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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 6 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with Checks; use Checks;
with Contracts; use Contracts;
with Debug; use Debug;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Elists; use Elists;
with Errout; use Errout;
with Expander; use Expander;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch6; use Exp_Ch6;
with Exp_Ch9; use Exp_Ch9;
with Exp_Dbug; use Exp_Dbug;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Ghost; use Ghost;
with Inline; use Inline;
with Itypes; use Itypes;
with Lib.Xref; use Lib.Xref;
with Layout; use Layout;
with Namet; use Namet;
with Lib; use Lib;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch4; use Sem_Ch4;
with Sem_Ch5; use Sem_Ch5;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch9; use Sem_Ch9;
with Sem_Ch10; use Sem_Ch10;
with Sem_Ch12; use Sem_Ch12;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Elim; use Sem_Elim;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Prag; use Sem_Prag;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Type; use Sem_Type;
with Sem_Warn; use Sem_Warn;
with Sinput; use Sinput;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Sinfo.CN; use Sinfo.CN;
with Snames; use Snames;
with Stringt; use Stringt;
with Style;
with Stylesw; use Stylesw;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with Urealp; use Urealp;
with Validsw; use Validsw;
package body Sem_Ch6 is
May_Hide_Profile : Boolean := False;
-- This flag is used to indicate that two formals in two subprograms being
-- checked for conformance differ only in that one is an access parameter
-- while the other is of a general access type with the same designated
-- type. In this case, if the rest of the signatures match, a call to
-- either subprogram may be ambiguous, which is worth a warning. The flag
-- is set in Compatible_Types, and the warning emitted in
-- New_Overloaded_Entity.
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Function_Return (N : Node_Id);
-- Subsidiary to Analyze_Return_Statement. Called when the return statement
-- applies to a [generic] function.
procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
-- Analyze a generic subprogram body. N is the body to be analyzed, and
-- Gen_Id is the defining entity Id for the corresponding spec.
procedure Analyze_Null_Procedure
(N : Node_Id;
Is_Completion : out Boolean);
-- A null procedure can be a declaration or (Ada 2012) a completion
procedure Analyze_Return_Statement (N : Node_Id);
-- Common processing for simple and extended return statements
procedure Analyze_Return_Type (N : Node_Id);
-- Subsidiary to Process_Formals: analyze subtype mark in function
-- specification in a context where the formals are visible and hide
-- outer homographs.
procedure Analyze_Subprogram_Body_Helper (N : Node_Id);
-- Does all the real work of Analyze_Subprogram_Body. This is split out so
-- that we can use RETURN but not skip the debug output at the end.
procedure Check_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Ctype : Conformance_Type;
Errmsg : Boolean;
Conforms : out Boolean;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False;
Skip_Controlling_Formals : Boolean := False);
-- Given two entities, this procedure checks that the profiles associated
-- with these entities meet the conformance criterion given by the third
-- parameter. If they conform, Conforms is set True and control returns
-- to the caller. If they do not conform, Conforms is set to False, and
-- in addition, if Errmsg is True on the call, proper messages are output
-- to complain about the conformance failure. If Err_Loc is non_Empty
-- the error messages are placed on Err_Loc, if Err_Loc is empty, then
-- error messages are placed on the appropriate part of the construct
-- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
-- against a formal access-to-subprogram type so Get_Instance_Of must
-- be called.
procedure Check_Formal_Subprogram_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id;
Errmsg : Boolean;
Conforms : out Boolean);
-- Core implementation of Check_Formal_Subprogram_Conformance from spec.
-- Errmsg can be set to False to not emit error messages.
-- Conforms is set to True if there is conformance, False otherwise.
procedure Check_Limited_Return
(N : Node_Id;
Expr : Node_Id;
R_Type : Entity_Id);
-- Check the appropriate (Ada 95 or Ada 2005) rules for returning limited
-- types. Used only for simple return statements. Expr is the expression
-- returned.
procedure Check_Subprogram_Order (N : Node_Id);
-- N is the N_Subprogram_Body node for a subprogram. This routine applies
-- the alpha ordering rule for N if this ordering requirement applicable.
procedure Check_Returns
(HSS : Node_Id;
Mode : Character;
Err : out Boolean;
Proc : Entity_Id := Empty);
-- Called to check for missing return statements in a function body, or for
-- returns present in a procedure body which has No_Return set. HSS is the
-- handled statement sequence for the subprogram body. This procedure
-- checks all flow paths to make sure they either have return (Mode = 'F',
-- used for functions) or do not have a return (Mode = 'P', used for
-- No_Return procedures). The flag Err is set if there are any control
-- paths not explicitly terminated by a return in the function case, and is
-- True otherwise. Proc is the entity for the procedure case and is used
-- in posting the warning message.
procedure Check_Untagged_Equality (Eq_Op : Entity_Id);
-- In Ada 2012, a primitive equality operator on an untagged record type
-- must appear before the type is frozen, and have the same visibility as
-- that of the type. This procedure checks that this rule is met, and
-- otherwise emits an error on the subprogram declaration and a warning
-- on the earlier freeze point if it is easy to locate. In Ada 2012 mode,
-- this routine outputs errors (or warnings if -gnatd.E is set). In earlier
-- versions of Ada, warnings are output if Warn_On_Ada_2012_Incompatibility
-- is set, otherwise the call has no effect.
procedure Enter_Overloaded_Entity (S : Entity_Id);
-- This procedure makes S, a new overloaded entity, into the first visible
-- entity with that name.
function Is_Non_Overriding_Operation
(Prev_E : Entity_Id;
New_E : Entity_Id) return Boolean;
-- Enforce the rule given in 12.3(18): a private operation in an instance
-- overrides an inherited operation only if the corresponding operation
-- was overriding in the generic. This needs to be checked for primitive
-- operations of types derived (in the generic unit) from formal private
-- or formal derived types.
procedure Make_Inequality_Operator (S : Entity_Id);
-- Create the declaration for an inequality operator that is implicitly
-- created by a user-defined equality operator that yields a boolean.
procedure Preanalyze_Formal_Expression (N : Node_Id; T : Entity_Id);
-- Preanalysis of default expressions of subprogram formals. N is the
-- expression to be analyzed and T is the expected type.
procedure Set_Formal_Validity (Formal_Id : Entity_Id);
-- Formal_Id is an formal parameter entity. This procedure deals with
-- setting the proper validity status for this entity, which depends on
-- the kind of parameter and the validity checking mode.
---------------------------------------------
-- Analyze_Abstract_Subprogram_Declaration --
---------------------------------------------
procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
Scop : constant Entity_Id := Current_Scope;
Subp_Id : constant Entity_Id :=
Analyze_Subprogram_Specification (Specification (N));
begin
Generate_Definition (Subp_Id);
-- Set the SPARK mode from the current context (may be overwritten later
-- with explicit pragma).
Set_SPARK_Pragma (Subp_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Subp_Id);
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => Subp_Id,
Checks => True,
Warnings => True);
Set_Is_Abstract_Subprogram (Subp_Id);
New_Overloaded_Entity (Subp_Id);
Check_Delayed_Subprogram (Subp_Id);
Set_Categorization_From_Scope (Subp_Id, Scop);
if Ekind (Scope (Subp_Id)) = E_Protected_Type then
Error_Msg_N ("abstract subprogram not allowed in protected type", N);
-- Issue a warning if the abstract subprogram is neither a dispatching
-- operation nor an operation that overrides an inherited subprogram or
-- predefined operator, since this most likely indicates a mistake.
elsif Warn_On_Redundant_Constructs
and then not Is_Dispatching_Operation (Subp_Id)
and then not Present (Overridden_Operation (Subp_Id))
and then (not Is_Operator_Symbol_Name (Chars (Subp_Id))
or else Scop /= Scope (Etype (First_Formal (Subp_Id))))
then
Error_Msg_N
("abstract subprogram is not dispatching or overriding?r?", N);
end if;
Generate_Reference_To_Formals (Subp_Id);
Check_Eliminated (Subp_Id);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Subp_Id);
end if;
end Analyze_Abstract_Subprogram_Declaration;
---------------------------------
-- Analyze_Expression_Function --
---------------------------------
procedure Analyze_Expression_Function (N : Node_Id) is
Expr : constant Node_Id := Expression (N);
Loc : constant Source_Ptr := Sloc (N);
LocX : constant Source_Ptr := Sloc (Expr);
Spec : constant Node_Id := Specification (N);
-- Local variables
Asp : Node_Id;
New_Body : Node_Id;
New_Spec : Node_Id;
Orig_N : Node_Id := Empty;
Ret : Node_Id;
Typ : Entity_Id := Empty;
Def_Id : Entity_Id := Empty;
Prev : Entity_Id;
-- If the expression is a completion, Prev is the entity whose
-- declaration is completed. Def_Id is needed to analyze the spec.
begin
-- This is one of the occasions on which we transform the tree during
-- semantic analysis. If this is a completion, transform the expression
-- function into an equivalent subprogram body, and analyze it.
-- Expression functions are inlined unconditionally. The back-end will
-- determine whether this is possible.
Inline_Processing_Required := True;
-- Create a specification for the generated body. This must be done
-- prior to the analysis of the initial declaration.
New_Spec := Copy_Subprogram_Spec (Spec);
Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
-- If there are previous overloadable entities with the same name,
-- check whether any of them is completed by the expression function.
-- In a generic context a formal subprogram has no completion.
if Present (Prev)
and then Is_Overloadable (Prev)
and then not Is_Formal_Subprogram (Prev)
then
Def_Id := Analyze_Subprogram_Specification (Spec);
Prev := Find_Corresponding_Spec (N);
Typ := Etype (Def_Id);
-- The previous entity may be an expression function as well, in
-- which case the redeclaration is illegal.
if Present (Prev)
and then Nkind (Original_Node (Unit_Declaration_Node (Prev))) =
N_Expression_Function
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("& conflicts with declaration#", Def_Id);
return;
end if;
end if;
Ret := Make_Simple_Return_Statement (LocX, Expr);
New_Body :=
Make_Subprogram_Body (Loc,
Specification => New_Spec,
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (LocX,
Statements => New_List (Ret)));
Set_Was_Expression_Function (New_Body);
-- If the expression completes a generic subprogram, we must create a
-- separate node for the body, because at instantiation the original
-- node of the generic copy must be a generic subprogram body, and
-- cannot be a expression function. Otherwise we just rewrite the
-- expression with the non-generic body.
if Present (Prev) and then Ekind (Prev) = E_Generic_Function then
Insert_After (N, New_Body);
-- Propagate any aspects or pragmas that apply to the expression
-- function to the proper body when the expression function acts
-- as a completion.
if Has_Aspects (N) then
Move_Aspects (N, To => New_Body);
end if;
Relocate_Pragmas_To_Body (New_Body);
Rewrite (N, Make_Null_Statement (Loc));
Set_Has_Completion (Prev, False);
Analyze (N);
Analyze (New_Body);
Set_Is_Inlined (Prev);
elsif Present (Prev)
and then Is_Overloadable (Prev)
and then not Is_Formal_Subprogram (Prev)
then
Set_Has_Completion (Prev, False);
Set_Is_Inlined (Prev);
-- AI12-0103: Expression functions that are a completion freeze their
-- expression but don't freeze anything else (unlike regular bodies).
-- Note that we cannot defer this freezing to the analysis of the
-- expression itself, because a freeze node might appear in a nested
-- scope, leading to an elaboration order issue in gigi.
-- As elsewhere, we do not emit freeze nodes within a generic unit.
if not Inside_A_Generic then
Freeze_Expr_Types
(Def_Id => Def_Id,
Typ => Typ,
Expr => Expr,
N => N);
end if;
-- For navigation purposes, indicate that the function is a body
Generate_Reference (Prev, Defining_Entity (N), 'b', Force => True);
Rewrite (N, New_Body);
-- Remove any existing aspects from the original node because the act
-- of rewriting causes the list to be shared between the two nodes.
Orig_N := Original_Node (N);
Remove_Aspects (Orig_N);
-- Propagate any pragmas that apply to expression function to the
-- proper body when the expression function acts as a completion.
-- Aspects are automatically transfered because of node rewriting.
Relocate_Pragmas_To_Body (N);
Analyze (N);
-- Prev is the previous entity with the same name, but it is can
-- be an unrelated spec that is not completed by the expression
-- function. In that case the relevant entity is the one in the body.
-- Not clear that the backend can inline it in this case ???
if Has_Completion (Prev) then
-- The formals of the expression function are body formals,
-- and do not appear in the ali file, which will only contain
-- references to the formals of the original subprogram spec.
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (Def_Id);
F2 := First_Formal (Prev);
while Present (F1) loop
Set_Spec_Entity (F1, F2);
Next_Formal (F1);
Next_Formal (F2);
end loop;
end;
else
Set_Is_Inlined (Defining_Entity (New_Body));
end if;
-- If this is not a completion, create both a declaration and a body, so
-- that the expression can be inlined whenever possible.
else
-- An expression function that is not a completion is not a
-- subprogram declaration, and thus cannot appear in a protected
-- definition.
if Nkind (Parent (N)) = N_Protected_Definition then
Error_Msg_N
("an expression function is not a legal protected operation", N);
end if;
Rewrite (N, Make_Subprogram_Declaration (Loc, Specification => Spec));
-- Remove any existing aspects from the original node because the act
-- of rewriting causes the list to be shared between the two nodes.
Orig_N := Original_Node (N);
Remove_Aspects (Orig_N);
Analyze (N);
-- If aspect SPARK_Mode was specified on the body, it needs to be
-- repeated both on the generated spec and the body.
Asp := Find_Aspect (Defining_Unit_Name (Spec), Aspect_SPARK_Mode);
if Present (Asp) then
Asp := New_Copy_Tree (Asp);
Set_Analyzed (Asp, False);
Set_Aspect_Specifications (New_Body, New_List (Asp));
end if;
Def_Id := Defining_Entity (N);
Set_Is_Inlined (Def_Id);
Typ := Etype (Def_Id);
-- Establish the linkages between the spec and the body. These are
-- used when the expression function acts as the prefix of attribute
-- 'Access in order to freeze the original expression which has been
-- moved to the generated body.
Set_Corresponding_Body (N, Defining_Entity (New_Body));
Set_Corresponding_Spec (New_Body, Def_Id);
-- Within a generic preanalyze the original expression for name
-- capture. The body is also generated but plays no role in
-- this because it is not part of the original source.
-- If this is an ignored Ghost entity, analysis of the generated
-- body is needed to hide external references (as is done in
-- Analyze_Subprogram_Body) after which the the subprogram profile
-- can be frozen, which is needed to expand calls to such an ignored
-- Ghost subprogram.
if Inside_A_Generic then
Set_Has_Completion (Def_Id, not Is_Ignored_Ghost_Entity (Def_Id));
Push_Scope (Def_Id);
Install_Formals (Def_Id);
Preanalyze_Spec_Expression (Expr, Typ);
End_Scope;
else
Push_Scope (Def_Id);
Install_Formals (Def_Id);
Preanalyze_Formal_Expression (Expr, Typ);
Check_Limited_Return (Orig_N, Expr, Typ);
End_Scope;
end if;
-- If this is a wrapper created in an instance for a formal
-- subprogram, insert body after declaration, to be analyzed when the
-- enclosing instance is analyzed.
if GNATprove_Mode
and then Is_Generic_Actual_Subprogram (Def_Id)
then
Insert_After (N, New_Body);
-- To prevent premature freeze action, insert the new body at the end
-- of the current declarations, or at the end of the package spec.
-- However, resolve usage names now, to prevent spurious visibility
-- on later entities. Note that the function can now be called in
-- the current declarative part, which will appear to be prior to the
-- presence of the body in the code. There are nevertheless no order
-- of elaboration issues because all name resolution has taken place
-- at the point of declaration.
else
declare
Decls : List_Id := List_Containing (N);
Par : constant Node_Id := Parent (Decls);
begin
if Nkind (Par) = N_Package_Specification
and then Decls = Visible_Declarations (Par)
and then not Is_Empty_List (Private_Declarations (Par))
then
Decls := Private_Declarations (Par);
end if;
Insert_After (Last (Decls), New_Body);
end;
end if;
-- In the case of an expression function marked with the aspect
-- Static, we need to check the requirement that the function's
-- expression is a potentially static expression. This is done
-- by making a full copy of the expression tree and performing
-- a special preanalysis on that tree with the global flag
-- Checking_Potentially_Static_Expression enabled. If the
-- resulting expression is static, then it's OK, but if not, that
-- means the expression violates the requirements of the Ada 2022
-- RM in 4.9(3.2/5-3.4/5) and we flag an error.
if Is_Static_Function (Def_Id) then
if not Is_Static_Expression (Expr) then
declare
Exp_Copy : constant Node_Id := New_Copy_Tree (Expr);
begin
Set_Checking_Potentially_Static_Expression (True);
Preanalyze_Formal_Expression (Exp_Copy, Typ);
if not Is_Static_Expression (Exp_Copy) then
Error_Msg_N
("static expression function requires "
& "potentially static expression", Expr);
end if;
Set_Checking_Potentially_Static_Expression (False);
end;
end if;
-- We also make an additional copy of the expression and
-- replace the expression of the expression function with
-- this copy, because the currently present expression is
-- now associated with the body created for the static
-- expression function, which will later be analyzed and
-- possibly rewritten, and we need to have the separate
-- unanalyzed copy available for use with later static
-- calls.
Set_Expression
(Original_Node (Subprogram_Spec (Def_Id)),
New_Copy_Tree (Expr));
-- Mark static expression functions as inlined, to ensure
-- that even calls with nonstatic actuals will be inlined.
Set_Has_Pragma_Inline (Def_Id);
Set_Is_Inlined (Def_Id);
end if;
end if;
-- Check incorrect use of dynamically tagged expression. This doesn't
-- fall out automatically when analyzing the generated function body,
-- because Check_Dynamically_Tagged_Expression deliberately ignores
-- nodes that don't come from source.
if Present (Def_Id)
and then Is_Tagged_Type (Typ)
then
Check_Dynamically_Tagged_Expression
(Expr => Expr,
Typ => Typ,
Related_Nod => Orig_N);
end if;
-- We must enforce checks for unreferenced formals in our newly
-- generated function, so we propagate the referenced flag from the
-- original spec to the new spec as well as setting Comes_From_Source.
if Present (Parameter_Specifications (New_Spec)) then
declare
Form_New_Def : Entity_Id;
Form_New_Spec : Node_Id;
Form_Old_Def : Entity_Id;
Form_Old_Spec : Node_Id;
begin
Form_New_Spec := First (Parameter_Specifications (New_Spec));
Form_Old_Spec := First (Parameter_Specifications (Spec));
while Present (Form_New_Spec) and then Present (Form_Old_Spec) loop
Form_New_Def := Defining_Identifier (Form_New_Spec);
Form_Old_Def := Defining_Identifier (Form_Old_Spec);
Set_Comes_From_Source (Form_New_Def, True);
-- Because of the usefulness of unreferenced controlling
-- formals we exempt them from unreferenced warnings by marking
-- them as always referenced.
Set_Referenced (Form_Old_Def,
(Is_Formal (Form_Old_Def)
and then Is_Controlling_Formal (Form_Old_Def))
or else Referenced (Form_Old_Def));
Next (Form_New_Spec);
Next (Form_Old_Spec);
end loop;
end;
end if;
end Analyze_Expression_Function;
---------------------------------------
-- Analyze_Extended_Return_Statement --
---------------------------------------
procedure Analyze_Extended_Return_Statement (N : Node_Id) is
begin
Check_Compiler_Unit ("extended return statement", N);
Analyze_Return_Statement (N);
end Analyze_Extended_Return_Statement;
----------------------------
-- Analyze_Function_Call --
----------------------------
procedure Analyze_Function_Call (N : Node_Id) is
Actuals : constant List_Id := Parameter_Associations (N);
Func_Nam : constant Node_Id := Name (N);
Actual : Node_Id;
begin
Analyze (Func_Nam);
-- A call of the form A.B (X) may be an Ada 2005 call, which is
-- rewritten as B (A, X). If the rewriting is successful, the call
-- has been analyzed and we just return.
if Nkind (Func_Nam) = N_Selected_Component
and then Name (N) /= Func_Nam
and then Is_Rewrite_Substitution (N)
and then Present (Etype (N))
then
return;
end if;
-- If error analyzing name, then set Any_Type as result type and return
if Etype (Func_Nam) = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- Otherwise analyze the parameters
if Present (Actuals) then
Actual := First (Actuals);
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
Next (Actual);
end loop;
end if;
Analyze_Call (N);
end Analyze_Function_Call;
-----------------------------
-- Analyze_Function_Return --
-----------------------------
procedure Analyze_Function_Return (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Stm_Entity : constant Entity_Id := Return_Statement_Entity (N);
Scope_Id : constant Entity_Id := Return_Applies_To (Stm_Entity);
R_Type : constant Entity_Id := Etype (Scope_Id);
-- Function result subtype
procedure Check_No_Return_Expression (Return_Expr : Node_Id);
-- Ada 2022: Check that the return expression in a No_Return function
-- meets the conditions specified by RM 6.5.1(5.1/5).
procedure Check_Return_Construct_Accessibility (Return_Stmt : Node_Id);
-- Apply legality rule of 6.5 (5.9) to the access discriminants of an
-- aggregate in a return statement.
procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id);
-- Check that the return_subtype_indication properly matches the result
-- subtype of the function, as required by RM-6.5(5.1/2-5.3/2).
--------------------------------
-- Check_No_Return_Expression --
--------------------------------
procedure Check_No_Return_Expression (Return_Expr : Node_Id) is
Kind : constant Node_Kind := Nkind (Return_Expr);
begin
if Kind = N_Raise_Expression then
return;
elsif Kind = N_Function_Call
and then Is_Entity_Name (Name (Return_Expr))
and then Ekind (Entity (Name (Return_Expr))) in
E_Function | E_Generic_Function
and then No_Return (Entity (Name (Return_Expr)))
then
return;
end if;
Error_Msg_N
("illegal expression in RETURN statement of No_Return function",
Return_Expr);
Error_Msg_N
("\must be raise expression or call to No_Return (RM 6.5.1(5.1/5))",
Return_Expr);
end Check_No_Return_Expression;
------------------------------------------
-- Check_Return_Construct_Accessibility --
------------------------------------------
procedure Check_Return_Construct_Accessibility (Return_Stmt : Node_Id) is
function First_Selector (Assoc : Node_Id) return Node_Id;
-- Obtain the first selector or choice from a given association
--------------------
-- First_Selector --
--------------------
function First_Selector (Assoc : Node_Id) return Node_Id is
begin
if Nkind (Assoc) = N_Component_Association then
return First (Choices (Assoc));
elsif Nkind (Assoc) = N_Discriminant_Association then
return (First (Selector_Names (Assoc)));
else
raise Program_Error;
end if;
end First_Selector;
-- Local declarations
Assoc : Node_Id := Empty;
-- Assoc should perhaps be renamed and declared as a
-- Node_Or_Entity_Id since it encompasses not only component and
-- discriminant associations, but also discriminant components within
-- a type declaration or subtype indication ???
Assoc_Expr : Node_Id;
Assoc_Present : Boolean := False;
Unseen_Disc_Count : Nat := 0;
Seen_Discs : Elist_Id;
Disc : Entity_Id;
First_Disc : Entity_Id;
Obj_Decl : Node_Id;
Return_Con : Node_Id;
Unqual : Node_Id;
-- Start of processing for Check_Return_Construct_Accessibility
begin
-- Only perform checks on record types with access discriminants and
-- non-internally generated functions.
if not Is_Record_Type (R_Type)
or else not Has_Anonymous_Access_Discriminant (R_Type)
or else not Comes_From_Source (Return_Stmt)
then
return;
end if;
-- We are only interested in return statements
if Nkind (Return_Stmt) not in
N_Extended_Return_Statement | N_Simple_Return_Statement
then
return;
end if;
-- Fetch the object from the return statement, in the case of a
-- simple return statement the expression is part of the node.
if Nkind (Return_Stmt) = N_Extended_Return_Statement then
-- Obtain the object definition from the expanded extended return
Return_Con := First (Return_Object_Declarations (Return_Stmt));
while Present (Return_Con) loop
-- Inspect the original node to avoid object declarations
-- expanded into renamings.
if Nkind (Original_Node (Return_Con)) = N_Object_Declaration
and then Comes_From_Source (Original_Node (Return_Con))
then
exit;
end if;
Nlists.Next (Return_Con);
end loop;
pragma Assert (Present (Return_Con));
-- Could be dealing with a renaming
Return_Con := Original_Node (Return_Con);
else
Return_Con := Expression (Return_Stmt);
end if;
-- Obtain the accessibility levels of the expressions associated
-- with all anonymous access discriminants, then generate a
-- dynamic check or static error when relevant.
Unqual := Unqualify (Original_Node (Return_Con));
-- Get the corresponding declaration based on the return object's
-- identifier.
if Nkind (Unqual) = N_Identifier
and then Nkind (Parent (Entity (Unqual)))
in N_Object_Declaration
| N_Object_Renaming_Declaration
then
Obj_Decl := Original_Node (Parent (Entity (Unqual)));
-- We were passed the object declaration directly, so use it
elsif Nkind (Unqual) in N_Object_Declaration
| N_Object_Renaming_Declaration
then
Obj_Decl := Unqual;
-- Otherwise, we are looking at something else
else
Obj_Decl := Empty;
end if;
-- Hop up object renamings when present
if Present (Obj_Decl)
and then Nkind (Obj_Decl) = N_Object_Renaming_Declaration
then
while Nkind (Obj_Decl) = N_Object_Renaming_Declaration loop
if Nkind (Name (Obj_Decl)) not in N_Entity then
-- We may be looking at the expansion of iterators or
-- some other internally generated construct, so it is safe
-- to ignore checks ???
if not Comes_From_Source (Obj_Decl) then
return;
end if;
Obj_Decl := Original_Node
(Declaration_Node
(Ultimate_Prefix (Name (Obj_Decl))));
-- Move up to the next declaration based on the object's name
else
Obj_Decl := Original_Node
(Declaration_Node (Name (Obj_Decl)));
end if;
end loop;
end if;
-- Obtain the discriminant values from the return aggregate
-- Do we cover extension aggregates correctly ???
if Nkind (Unqual) = N_Aggregate then
if Present (Expressions (Unqual)) then
Assoc := First (Expressions (Unqual));
else
Assoc := First (Component_Associations (Unqual));
end if;
-- There is an object declaration for the return object
elsif Present (Obj_Decl) then
-- When a subtype indication is present in an object declaration
-- it must contain the object's discriminants.
if Nkind (Object_Definition (Obj_Decl)) = N_Subtype_Indication then
Assoc := First
(Constraints
(Constraint
(Object_Definition (Obj_Decl))));
-- The object declaration contains an aggregate
elsif Present (Expression (Obj_Decl)) then
if Nkind (Unqualify (Expression (Obj_Decl))) = N_Aggregate then
-- Grab the first associated discriminant expresion
if Present
(Expressions (Unqualify (Expression (Obj_Decl))))
then
Assoc := First
(Expressions
(Unqualify (Expression (Obj_Decl))));
else
Assoc := First
(Component_Associations
(Unqualify (Expression (Obj_Decl))));
end if;
-- Otherwise, this is something else
else
return;
end if;
-- There are no supplied discriminants in the object declaration,
-- so get them from the type definition since they must be default
-- initialized.
-- Do we handle constrained subtypes correctly ???
elsif Nkind (Unqual) = N_Object_Declaration then
Assoc := First_Discriminant
(Etype (Object_Definition (Obj_Decl)));
else
Assoc := First_Discriminant (Etype (Unqual));
end if;
-- When we are not looking at an aggregate or an identifier, return
-- since any other construct (like a function call) is not
-- applicable since checks will be performed on the side of the
-- callee.
else
return;
end if;
-- Obtain the discriminants so we know the actual type in case the
-- value of their associated expression gets implicitly converted.
if No (Obj_Decl) then
pragma Assert (Nkind (Unqual) = N_Aggregate);
Disc := First_Discriminant (Etype (Unqual));
else
Disc := First_Discriminant
(Etype (Defining_Identifier (Obj_Decl)));
end if;
-- Preserve the first discriminant for checking named associations
First_Disc := Disc;
-- Count the number of discriminants for processing an aggregate
-- which includes an others.
Disc := First_Disc;
while Present (Disc) loop
Unseen_Disc_Count := Unseen_Disc_Count + 1;
Next_Discriminant (Disc);
end loop;
Seen_Discs := New_Elmt_List;
-- Loop through each of the discriminants and check each expression
-- associated with an anonymous access discriminant.
-- When named associations occur in the return aggregate then
-- discriminants can be in any order, so we need to ensure we do
-- not continue to loop when all discriminants have been seen.
Disc := First_Disc;
while Present (Assoc)
and then (Present (Disc) or else Assoc_Present)
and then Unseen_Disc_Count > 0
loop
-- Handle named associations by searching through the names of
-- the relevant discriminant components.
if Nkind (Assoc)
in N_Component_Association | N_Discriminant_Association
then
Assoc_Expr := Expression (Assoc);
Assoc_Present := True;
-- We currently don't handle box initialized discriminants,
-- however, since default initialized anonymous access
-- discriminants are a corner case, this is ok for now ???
if Nkind (Assoc) = N_Component_Association
and then Box_Present (Assoc)
then
Assoc_Present := False;
if Nkind (First_Selector (Assoc)) = N_Others_Choice then
Unseen_Disc_Count := 0;
end if;
-- When others is present we must identify a discriminant we
-- haven't already seen so as to get the appropriate type for
-- the static accessibility check.
-- This works because all components within an others clause
-- must have the same type.
elsif Nkind (First_Selector (Assoc)) = N_Others_Choice then
Disc := First_Disc;
Outer : while Present (Disc) loop
declare
Current_Seen_Disc : Elmt_Id;
begin
-- Move through the list of identified discriminants
Current_Seen_Disc := First_Elmt (Seen_Discs);
while Present (Current_Seen_Disc) loop
-- Exit the loop when we found a match
exit when
Chars (Node (Current_Seen_Disc)) = Chars (Disc);
Next_Elmt (Current_Seen_Disc);
end loop;
-- When we have exited the above loop without finding
-- a match then we know that Disc has not been seen.
exit Outer when No (Current_Seen_Disc);
end;
Next_Discriminant (Disc);
end loop Outer;
-- If we got to an others clause with a non-zero
-- discriminant count there must be a discriminant left to
-- check.
pragma Assert (Present (Disc));
-- Set the unseen discriminant count to zero because we know
-- an others clause sets all remaining components of an
-- aggregate.
Unseen_Disc_Count := 0;
-- Move through each of the selectors in the named association
-- and obtain a discriminant for accessibility checking if one
-- is referenced in the list. Also track which discriminants
-- are referenced for the purpose of handling an others clause.
else
declare
Assoc_Choice : Node_Id;
Curr_Disc : Node_Id;
begin
Disc := Empty;
Curr_Disc := First_Disc;
while Present (Curr_Disc) loop
-- Check each of the choices in the associations for a
-- match to the name of the current discriminant.
Assoc_Choice := First_Selector (Assoc);
while Present (Assoc_Choice) loop
-- When the name matches we track that we have seen
-- the discriminant, but instead of exiting the
-- loop we continue iterating to make sure all the
-- discriminants within the named association get
-- tracked.
if Chars (Assoc_Choice) = Chars (Curr_Disc) then
Append_Elmt (Curr_Disc, Seen_Discs);
Disc := Curr_Disc;
Unseen_Disc_Count := Unseen_Disc_Count - 1;
end if;
Next (Assoc_Choice);
end loop;
Next_Discriminant (Curr_Disc);
end loop;
end;
end if;
-- Unwrap the associated expression if we are looking at a default
-- initialized type declaration. In this case Assoc is not really
-- an association, but a component declaration. Should Assoc be
-- renamed in some way to be more clear ???
-- This occurs when the return object does not initialize
-- discriminant and instead relies on the type declaration for
-- their supplied values.
elsif Nkind (Assoc) in N_Entity
and then Ekind (Assoc) = E_Discriminant
then
Append_Elmt (Disc, Seen_Discs);
Assoc_Expr := Discriminant_Default_Value (Assoc);
Unseen_Disc_Count := Unseen_Disc_Count - 1;
-- Otherwise, there is nothing to do because Assoc is an
-- expression within the return aggregate itself.
else
Append_Elmt (Disc, Seen_Discs);
Assoc_Expr := Assoc;
Unseen_Disc_Count := Unseen_Disc_Count - 1;
end if;
-- Check the accessibility level of the expression when the
-- discriminant is of an anonymous access type.
if Present (Assoc_Expr)
and then Present (Disc)
and then Ekind (Etype (Disc)) = E_Anonymous_Access_Type
then
-- Perform a static check first, if possible
if Static_Accessibility_Level
(Expr => Assoc_Expr,
Level => Zero_On_Dynamic_Level,
In_Return_Context => True)
> Scope_Depth (Scope (Scope_Id))
then
Error_Msg_N
("access discriminant in return object would be a dangling"
& " reference", Return_Stmt);
exit;
end if;
-- Otherwise, generate a dynamic check based on the extra
-- accessibility of the result.
if Present (Extra_Accessibility_Of_Result (Scope_Id)) then
Insert_Before_And_Analyze (Return_Stmt,
Make_Raise_Program_Error (Loc,
Condition =>
Make_Op_Gt (Loc,
Left_Opnd => Accessibility_Level
(Expr => Assoc_Expr,
Level => Dynamic_Level,
In_Return_Context => True),
Right_Opnd => Extra_Accessibility_Of_Result
(Scope_Id)),
Reason => PE_Accessibility_Check_Failed));
end if;
end if;
-- Iterate over the discriminants, except when we have encountered
-- a named association since the discriminant order becomes
-- irrelevant in that case.
if not Assoc_Present then
Next_Discriminant (Disc);
end if;
-- Iterate over associations
if not Is_List_Member (Assoc) then
exit;
else
Nlists.Next (Assoc);
end if;
end loop;
end Check_Return_Construct_Accessibility;
-------------------------------------
-- Check_Return_Subtype_Indication --
-------------------------------------
procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is
Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl);
R_Stm_Type : constant Entity_Id := Etype (Return_Obj);
-- Subtype given in the extended return statement (must match R_Type)
Subtype_Ind : constant Node_Id :=
Object_Definition (Original_Node (Obj_Decl));
procedure Error_No_Match (N : Node_Id);
-- Output error messages for case where types do not statically
-- match. N is the location for the messages.
--------------------
-- Error_No_Match --
--------------------
procedure Error_No_Match (N : Node_Id) is
begin
Error_Msg_N
("subtype must statically match function result subtype", N);
if not Predicates_Match (R_Stm_Type, R_Type) then
Error_Msg_Node_2 := R_Type;
Error_Msg_NE
("\predicate of& does not match predicate of&",
N, R_Stm_Type);
end if;
end Error_No_Match;
-- Start of processing for Check_Return_Subtype_Indication
begin
-- First, avoid cascaded errors
if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then
return;
end if;
-- "return access T" case; check that the return statement also has
-- "access T", and that the subtypes statically match:
-- if this is an access to subprogram the signatures must match.
if Is_Anonymous_Access_Type (R_Type) then
if Is_Anonymous_Access_Type (R_Stm_Type) then
if Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type
then
if Base_Type (Designated_Type (R_Stm_Type)) /=
Base_Type (Designated_Type (R_Type))
or else not Subtypes_Statically_Match (R_Stm_Type, R_Type)
then
Error_No_Match (Subtype_Mark (Subtype_Ind));
end if;
else
-- For two anonymous access to subprogram types, the types
-- themselves must be type conformant.
if not Conforming_Types
(R_Stm_Type, R_Type, Fully_Conformant)
then
Error_No_Match (Subtype_Ind);
end if;
end if;
else
Error_Msg_N ("must use anonymous access type", Subtype_Ind);
end if;
-- If the return object is of an anonymous access type, then report
-- an error if the function's result type is not also anonymous.
elsif Is_Anonymous_Access_Type (R_Stm_Type) then
pragma Assert (not Is_Anonymous_Access_Type (R_Type));
Error_Msg_N
("anonymous access not allowed for function with named access "
& "result", Subtype_Ind);
-- Subtype indication case: check that the return object's type is
-- covered by the result type, and that the subtypes statically match
-- when the result subtype is constrained. Also handle record types
-- with unknown discriminants for which we have built the underlying
-- record view. Coverage is needed to allow specific-type return
-- objects when the result type is class-wide (see AI05-32).
elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type))
or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type))
and then
Covers
(Base_Type (R_Type),
Underlying_Record_View (Base_Type (R_Stm_Type))))
then
-- A null exclusion may be present on the return type, on the
-- function specification, on the object declaration or on the
-- subtype itself.
if Is_Access_Type (R_Type)
and then
(Can_Never_Be_Null (R_Type)
or else Null_Exclusion_Present (Parent (Scope_Id))) /=
Can_Never_Be_Null (R_Stm_Type)
then
Error_No_Match (Subtype_Ind);
end if;
-- AI05-103: for elementary types, subtypes must statically match
if Is_Constrained (R_Type) or else Is_Access_Type (R_Type) then
if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then
Error_No_Match (Subtype_Ind);
end if;
end if;
-- All remaining cases are illegal
-- Note: previous versions of this subprogram allowed the return
-- value to be the ancestor of the return type if the return type
-- was a null extension. This was plainly incorrect.
else
Error_Msg_N
("wrong type for return_subtype_indication", Subtype_Ind);
end if;
end Check_Return_Subtype_Indication;
---------------------
-- Local Variables --
---------------------
Expr : Node_Id;
Obj_Decl : Node_Id := Empty;
-- Start of processing for Analyze_Function_Return
begin
Set_Return_Present (Scope_Id);
if Nkind (N) = N_Simple_Return_Statement then
Expr := Expression (N);
-- Guard against a malformed expression. The parser may have tried to
-- recover but the node is not analyzable.
if Nkind (Expr) = N_Error then
Set_Etype (Expr, Any_Type);
Expander_Mode_Save_And_Set (False);
return;
else
-- The resolution of a controlled [extension] aggregate associated
-- with a return statement creates a temporary which needs to be
-- finalized on function exit. Wrap the return statement inside a
-- block so that the finalization machinery can detect this case.
-- This early expansion is done only when the return statement is
-- not part of a handled sequence of statements.
if Nkind (Expr) in N_Aggregate | N_Extension_Aggregate
and then Needs_Finalization (R_Type)
and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements
then
Rewrite (N,
Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Relocate_Node (N)))));
Analyze (N);
return;
end if;
Analyze (Expr);
-- Ada 2005 (AI-251): If the type of the returned object is
-- an access to an interface type then we add an implicit type
-- conversion to force the displacement of the "this" pointer to
-- reference the secondary dispatch table. We cannot delay the
-- generation of this implicit conversion until the expansion
-- because in this case the type resolution changes the decoration
-- of the expression node to match R_Type; by contrast, if the
-- returned object is a class-wide interface type then it is too
-- early to generate here the implicit conversion since the return
-- statement may be rewritten by the expander into an extended
-- return statement whose expansion takes care of adding the
-- implicit type conversion to displace the pointer to the object.
if Expander_Active
and then Serious_Errors_Detected = 0
and then Is_Access_Type (R_Type)
and then Nkind (Expr) not in N_Null | N_Raise_Expression
and then Is_Interface (Designated_Type (R_Type))
and then Is_Progenitor (Designated_Type (R_Type),
Designated_Type (Etype (Expr)))
then
Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr)));
Analyze (Expr);
end if;
Resolve (Expr, R_Type);
Check_Limited_Return (N, Expr, R_Type);
Check_Return_Construct_Accessibility (N);
-- Ada 2022 (AI12-0269): Any return statement that applies to a
-- nonreturning function shall be a simple_return_statement with
-- an expression that is a raise_expression, or else a call on a
-- nonreturning function, or else a parenthesized expression of
-- one of these.
if Ada_Version >= Ada_2022
and then No_Return (Scope_Id)
and then Comes_From_Source (N)
then
Check_No_Return_Expression (Original_Node (Expr));
end if;
end if;
else
Obj_Decl := Last (Return_Object_Declarations (N));
-- Analyze parts specific to extended_return_statement:
declare
Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl);
HSS : constant Node_Id := Handled_Statement_Sequence (N);
begin
Expr := Expression (Obj_Decl);
-- Note: The check for OK_For_Limited_Init will happen in
-- Analyze_Object_Declaration; we treat it as a normal
-- object declaration.
Set_Is_Return_Object (Defining_Identifier (Obj_Decl));
-- Returning a build-in-place unconstrained array type we defer
-- the full analysis of the returned object to avoid generating
-- the corresponding constrained subtype; otherwise the bounds
-- would be created in the stack and a dangling reference would
-- be returned pointing to the bounds. We perform its preanalysis
-- to report errors on the initializing aggregate now (if any);
-- we also ensure its activation chain and Master variable are
-- defined (if tasks are being declared) since they are generated
-- as part of the analysis and expansion of the object declaration
-- at this stage.
if Is_Array_Type (R_Type)
and then not Is_Constrained (R_Type)
and then Is_Build_In_Place_Function (Scope_Id)
and then Needs_BIP_Alloc_Form (Scope_Id)
and then Nkind (Expr) in N_Aggregate | N_Extension_Aggregate
then
Preanalyze (Obj_Decl);
if Expander_Active then
Ensure_Activation_Chain_And_Master (Obj_Decl);
end if;
else
Analyze (Obj_Decl);
end if;
Check_Return_Subtype_Indication (Obj_Decl);
if Present (HSS) then
Analyze (HSS);
if Present (Exception_Handlers (HSS)) then
-- ???Has_Nested_Block_With_Handler needs to be set.
-- Probably by creating an actual N_Block_Statement.
-- Probably in Expand.
null;
end if;
end if;
-- Mark the return object as referenced, since the return is an
-- implicit reference of the object.
Set_Referenced (Defining_Identifier (Obj_Decl));
Check_References (Stm_Entity);
Check_Return_Construct_Accessibility (N);
-- Check RM 6.5 (5.9/3)
if Has_Aliased then
if Ada_Version < Ada_2012
and then Warn_On_Ada_2012_Compatibility
then
Error_Msg_N
("ALIASED only allowed for limited return objects "
& "in Ada 2012?y?", N);
elsif not Is_Limited_View (R_Type) then
Error_Msg_N
("ALIASED only allowed for limited return objects", N);
end if;
end if;
-- Ada 2022 (AI12-0269): Any return statement that applies to a
-- nonreturning function shall be a simple_return_statement.
if Ada_Version >= Ada_2022
and then No_Return (Scope_Id)
and then Comes_From_Source (N)
then
Error_Msg_N
("extended RETURN statement not allowed in No_Return "
& "function", N);
end if;
end;
end if;
-- Case of Expr present
if Present (Expr) then
-- Defend against previous errors
if Nkind (Expr) = N_Empty
or else No (Etype (Expr))
then
return;
end if;
-- Apply constraint check. Note that this is done before the implicit
-- conversion of the expression done for anonymous access types to
-- ensure correct generation of the null-excluding check associated
-- with null-excluding expressions found in return statements. We
-- don't need a check if the subtype of the return object is the
-- same as the result subtype of the function.
if Nkind (N) /= N_Extended_Return_Statement
or else Nkind (Obj_Decl) /= N_Object_Declaration
or else Nkind (Object_Definition (Obj_Decl)) not in N_Has_Entity
or else Entity (Object_Definition (Obj_Decl)) /= R_Type
then
Apply_Constraint_Check (Expr, R_Type);
end if;
-- The return value is converted to the return type of the function,
-- which implies a predicate check if the return type is predicated.
-- We do not apply the check for an extended return statement because
-- Analyze_Object_Declaration has already done it on Obj_Decl above.
-- We do not apply the check to a case expression because it will
-- be expanded into a series of return statements, each of which
-- will receive a predicate check.
if Nkind (N) /= N_Extended_Return_Statement
and then Nkind (Expr) /= N_Case_Expression
then
Apply_Predicate_Check (Expr, R_Type);
end if;
-- Ada 2005 (AI-318-02): When the result type is an anonymous access
-- type, apply an implicit conversion of the expression to that type
-- to force appropriate static and run-time accessibility checks.
-- But we want to apply the checks to an extended return statement
-- only once, i.e. not to the simple return statement generated at
-- the end of its expansion because, prior to leaving the function,
-- the accessibility level of the return object changes to be a level
-- determined by the point of call (RM 3.10.2(10.8/3)).
if Ada_Version >= Ada_2005
and then Ekind (R_Type) = E_Anonymous_Access_Type
and then (Nkind (N) = N_Extended_Return_Statement
or else not Comes_From_Extended_Return_Statement (N))
then
Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr)));
Analyze_And_Resolve (Expr, R_Type);
-- If this is a local anonymous access to subprogram, the
-- accessibility check can be applied statically. The return is
-- illegal if the access type of the return expression is declared
-- inside of the subprogram (except if it is the subtype indication
-- of an extended return statement).
elsif Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type then
if not Comes_From_Source (Current_Scope)
or else Ekind (Current_Scope) = E_Return_Statement
then
null;
elsif
Scope_Depth (Scope (Etype (Expr))) >= Scope_Depth (Scope_Id)
then
Error_Msg_N ("cannot return local access to subprogram", N);
end if;
-- The expression cannot be of a formal incomplete type
elsif Ekind (Etype (Expr)) = E_Incomplete_Type
and then Is_Generic_Type (Etype (Expr))
then
Error_Msg_N
("cannot return expression of a formal incomplete type", N);
end if;
-- If the result type is class-wide, then check that the return
-- expression's type is not declared at a deeper level than the
-- function (RM05-6.5(5.6/2)).
if Ada_Version >= Ada_2005
and then Is_Class_Wide_Type (R_Type)
then
if Type_Access_Level (Etype (Expr)) >
Subprogram_Access_Level (Scope_Id)
then
Error_Msg_N
("level of return expression type is deeper than "
& "class-wide function!", Expr);
end if;
end if;
-- Check incorrect use of dynamically tagged expression
if Is_Tagged_Type (R_Type) then
Check_Dynamically_Tagged_Expression
(Expr => Expr,
Typ => R_Type,
Related_Nod => N);
end if;
-- Perform static accessibility checks for cases involving
-- dereferences of access parameters. Runtime accessibility checks
-- get generated elsewhere.
if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L)
and then Is_Limited_View (Etype (Scope_Id))
and then Static_Accessibility_Level (Expr, Zero_On_Dynamic_Level)
> Subprogram_Access_Level (Scope_Id)
then
-- Suppress the message in a generic, where the rewriting
-- is irrelevant.
if Inside_A_Generic then
null;
else
Rewrite (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Accessibility_Check_Failed));
Analyze (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("cannot return a local value by reference<<", N);
Error_Msg_NE ("\& [<<", N, Standard_Program_Error);
end if;
end if;
if Known_Null (Expr)
and then Nkind (Parent (Scope_Id)) = N_Function_Specification
and then Null_Exclusion_Present (Parent (Scope_Id))
then
Apply_Compile_Time_Constraint_Error
(N => Expr,
Msg => "(Ada 2005) null not allowed for "
& "null-excluding return??",
Reason => CE_Null_Not_Allowed);
end if;
-- RM 6.5 (5.4/3): accessibility checks also apply if the return object
-- has no initializing expression.
elsif Ada_Version > Ada_2005 and then Is_Class_Wide_Type (R_Type) then
if Type_Access_Level (Etype (Defining_Identifier (Obj_Decl))) >
Subprogram_Access_Level (Scope_Id)
then
Error_Msg_N
("level of return expression type is deeper than "
& "class-wide function!", Obj_Decl);
end if;
end if;
end Analyze_Function_Return;
-------------------------------------
-- Analyze_Generic_Subprogram_Body --
-------------------------------------
procedure Analyze_Generic_Subprogram_Body
(N : Node_Id;
Gen_Id : Entity_Id)
is
Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
Kind : constant Entity_Kind := Ekind (Gen_Id);
Body_Id : Entity_Id;
New_N : Node_Id;
Spec : Node_Id;
begin
-- Copy body and disable expansion while analyzing the generic For a
-- stub, do not copy the stub (which would load the proper body), this
-- will be done when the proper body is analyzed.
if Nkind (N) /= N_Subprogram_Body_Stub then
New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
Rewrite (N, New_N);
-- Once the contents of the generic copy and the template are
-- swapped, do the same for their respective aspect specifications.
Exchange_Aspects (N, New_N);
-- Collect all contract-related source pragmas found within the
-- template and attach them to the contract of the subprogram body.
-- This contract is used in the capture of global references within
-- annotations.
Create_Generic_Contract (N);
Start_Generic;
end if;
Spec := Specification (N);
-- Within the body of the generic, the subprogram is callable, and
-- behaves like the corresponding non-generic unit.
Body_Id := Defining_Entity (Spec);
if Kind = E_Generic_Procedure
and then Nkind (Spec) /= N_Procedure_Specification
then
Error_Msg_N ("invalid body for generic procedure", Body_Id);
return;
elsif Kind = E_Generic_Function
and then Nkind (Spec) /= N_Function_Specification
then
Error_Msg_N ("invalid body for generic function", Body_Id);
return;
end if;
Set_Corresponding_Body (Gen_Decl, Body_Id);
if Has_Completion (Gen_Id)
and then Nkind (Parent (N)) /= N_Subunit
then
Error_Msg_N ("duplicate generic body", N);
return;
else
Set_Has_Completion (Gen_Id);
end if;
if Nkind (N) = N_Subprogram_Body_Stub then
Mutate_Ekind (Defining_Entity (Specification (N)), Kind);
else
Set_Corresponding_Spec (N, Gen_Id);
end if;
if Nkind (Parent (N)) = N_Compilation_Unit then
Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
end if;
-- Make generic parameters immediately visible in the body. They are
-- needed to process the formals declarations. Then make the formals
-- visible in a separate step.
Push_Scope (Gen_Id);
declare
E : Entity_Id;
First_Ent : Entity_Id;
begin
First_Ent := First_Entity (Gen_Id);
E := First_Ent;
while Present (E) and then not Is_Formal (E) loop
Install_Entity (E);
Next_Entity (E);
end loop;
Set_Use (Generic_Formal_Declarations (Gen_Decl));
-- Now generic formals are visible, and the specification can be
-- analyzed, for subsequent conformance check.
Body_Id := Analyze_Subprogram_Specification (Spec);
-- Make formal parameters visible
if Present (E) then
-- E is the first formal parameter, we loop through the formals
-- installing them so that they will be visible.
Set_First_Entity (Gen_Id, E);
while Present (E) loop
Install_Entity (E);
Next_Formal (E);
end loop;
end if;
-- Visible generic entity is callable within its own body
Mutate_Ekind (Gen_Id, Ekind (Body_Id));
Reinit_Field_To_Zero (Body_Id, F_Has_Out_Or_In_Out_Parameter,
Old_Ekind =>
(E_Function | E_Procedure |
E_Generic_Function | E_Generic_Procedure => True,
others => False));
Mutate_Ekind (Body_Id, E_Subprogram_Body);
Set_Convention (Body_Id, Convention (Gen_Id));
Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id));
Set_Scope (Body_Id, Scope (Gen_Id));
Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id);
if Nkind (N) = N_Subprogram_Body_Stub then
-- No body to analyze, so restore state of generic unit
Mutate_Ekind (Gen_Id, Kind);
Mutate_Ekind (Body_Id, Kind);
if Present (First_Ent) then
Set_First_Entity (Gen_Id, First_Ent);
end if;
End_Scope;
return;
end if;
-- If this is a compilation unit, it must be made visible explicitly,
-- because the compilation of the declaration, unlike other library
-- unit declarations, does not. If it is not a unit, the following
-- is redundant but harmless.
Set_Is_Immediately_Visible (Gen_Id);
Reference_Body_Formals (Gen_Id, Body_Id);
if Is_Child_Unit (Gen_Id) then
Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False);
end if;
Set_Actual_Subtypes (N, Current_Scope);
Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Body_Id);
-- Analyze any aspect specifications that appear on the generic
-- subprogram body.
if Has_Aspects (N) then
Analyze_Aspects_On_Subprogram_Body_Or_Stub (N);
end if;
Analyze_Declarations (Declarations (N));
Check_Completion;
-- Process the contract of the subprogram body after all declarations
-- have been analyzed. This ensures that any contract-related pragmas
-- are available through the N_Contract node of the body.
Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id);
Analyze (Handled_Statement_Sequence (N));
Save_Global_References (Original_Node (N));
-- Prior to exiting the scope, include generic formals again (if any
-- are present) in the set of local entities.
if Present (First_Ent) then
Set_First_Entity (Gen_Id, First_Ent);
end if;
Check_References (Gen_Id);
end;
Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope);
Update_Use_Clause_Chain;
Validate_Categorization_Dependency (N, Gen_Id);
End_Scope;
Check_Subprogram_Order (N);
-- Outside of its body, unit is generic again
Reinit_Field_To_Zero (Gen_Id, F_Has_Nested_Subprogram,
Old_Ekind => (E_Function | E_Procedure => True, others => False));
Mutate_Ekind (Gen_Id, Kind);
Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False);
if Style_Check then
Style.Check_Identifier (Body_Id, Gen_Id);
end if;
End_Generic;
end Analyze_Generic_Subprogram_Body;
----------------------------
-- Analyze_Null_Procedure --
----------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos that jump to the end of the routine and restore the
-- Ghost mode.
procedure Analyze_Null_Procedure
(N : Node_Id;
Is_Completion : out Boolean)
is
Loc : constant Source_Ptr := Sloc (N);
Spec : constant Node_Id := Specification (N);
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
Saved_ISMP : constant Boolean :=
Ignore_SPARK_Mode_Pragmas_In_Instance;
-- Save the Ghost and SPARK mode-related data to restore on exit
Designator : Entity_Id;
Form : Node_Id;
Null_Body : Node_Id := Empty;
Null_Stmt : Node_Id := Null_Statement (Spec);
Prev : Entity_Id;
begin
Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
-- A null procedure is Ghost when it is stand-alone and is subject to
-- pragma Ghost, or when the corresponding spec is Ghost. Set the mode
-- now, to ensure that any nodes generated during analysis and expansion
-- are properly marked as Ghost.
if Present (Prev) then
Mark_And_Set_Ghost_Body (N, Prev);
end if;
-- Capture the profile of the null procedure before analysis, for
-- expansion at the freeze point and at each point of call. The body is
-- used if the procedure has preconditions, or if it is a completion. In
-- the first case the body is analyzed at the freeze point, in the other
-- it replaces the null procedure declaration.
-- For a null procedure that comes from source, a NULL statement is
-- provided by the parser, which carries the source location of the
-- NULL keyword, and has Comes_From_Source set. For a null procedure
-- from expansion, create one now.
if No (Null_Stmt) then
Null_Stmt := Make_Null_Statement (Loc);
end if;
Null_Body :=
Make_Subprogram_Body (Loc,
Specification => New_Copy_Tree (Spec),
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Null_Stmt)));
-- Create new entities for body and formals
Set_Defining_Unit_Name (Specification (Null_Body),
Make_Defining_Identifier
(Sloc (Defining_Entity (N)),
Chars (Defining_Entity (N))));
Form := First (Parameter_Specifications (Specification (Null_Body)));
while Present (Form) loop
Set_Defining_Identifier (Form,
Make_Defining_Identifier
(Sloc (Defining_Identifier (Form)),
Chars (Defining_Identifier (Form))));
Next (Form);
end loop;
-- Determine whether the null procedure may be a completion of a generic
-- suprogram, in which case we use the new null body as the completion
-- and set minimal semantic information on the original declaration,
-- which is rewritten as a null statement.
if Present (Prev) and then Is_Generic_Subprogram (Prev) then
Insert_Before (N, Null_Body);
Mutate_Ekind (Defining_Entity (N), Ekind (Prev));
Rewrite (N, Make_Null_Statement (Loc));
Analyze_Generic_Subprogram_Body (Null_Body, Prev);
Is_Completion := True;
goto Leave;
else
-- Resolve the types of the formals now, because the freeze point may
-- appear in a different context, e.g. an instantiation.
Form := First (Parameter_Specifications (Specification (Null_Body)));
while Present (Form) loop
if Nkind (Parameter_Type (Form)) /= N_Access_Definition then
Find_Type (Parameter_Type (Form));
elsif No (Access_To_Subprogram_Definition
(Parameter_Type (Form)))
then
Find_Type (Subtype_Mark (Parameter_Type (Form)));
-- The case of a null procedure with a formal that is an
-- access-to-subprogram type, and that is used as an actual
-- in an instantiation is left to the enthusiastic reader.
else
null;
end if;
Next (Form);
end loop;
end if;
-- If there are previous overloadable entities with the same name, check
-- whether any of them is completed by the null procedure.
if Present (Prev) and then Is_Overloadable (Prev) then
Designator := Analyze_Subprogram_Specification (Spec);
Prev := Find_Corresponding_Spec (N);
end if;
if No (Prev) or else not Comes_From_Source (Prev) then
Designator := Analyze_Subprogram_Specification (Spec);
Set_Has_Completion (Designator);
-- Signal to caller that this is a procedure declaration
Is_Completion := False;
-- Null procedures are always inlined, but generic formal subprograms
-- which appear as such in the internal instance of formal packages,
-- need no completion and are not marked Inline.
if Expander_Active
and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration
then
Set_Corresponding_Body (N, Defining_Entity (Null_Body));
Set_Body_To_Inline (N, Null_Body);
Set_Is_Inlined (Designator);
end if;
else
-- The null procedure is a completion. We unconditionally rewrite
-- this as a null body (even if expansion is not active), because
-- there are various error checks that are applied on this body
-- when it is analyzed (e.g. correct aspect placement).
if Has_Completion (Prev) then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_NE ("duplicate body for & declared#", N, Prev);
end if;
Check_Previous_Null_Procedure (N, Prev);
Is_Completion := True;
Rewrite (N, Null_Body);
Analyze (N);
end if;
<<Leave>>
Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP;
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Analyze_Null_Procedure;
-----------------------------
-- Analyze_Operator_Symbol --
-----------------------------
-- An operator symbol such as "+" or "and" may appear in context where the
-- literal denotes an entity name, such as "+"(x, y) or in context when it
-- is just a string, as in (conjunction = "or"). In these cases the parser
-- generates this node, and the semantics does the disambiguation. Other
-- such case are actuals in an instantiation, the generic unit in an
-- instantiation, pragma arguments, and aspect specifications.
procedure Analyze_Operator_Symbol (N : Node_Id) is
Par : constant Node_Id := Parent (N);
Maybe_Aspect_Spec : Node_Id := Par;
begin
if Nkind (Maybe_Aspect_Spec) /= N_Aspect_Specification then
-- deal with N_Aggregate nodes
Maybe_Aspect_Spec := Parent (Maybe_Aspect_Spec);
end if;
if (Nkind (Par) = N_Function_Call and then N = Name (Par))
or else Nkind (Par) = N_Function_Instantiation
or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par))
or else (Nkind (Par) = N_Pragma_Argument_Association
and then not Is_Pragma_String_Literal (Par))
or else Nkind (Par) = N_Subprogram_Renaming_Declaration
or else (Nkind (Par) = N_Attribute_Reference
and then Attribute_Name (Par) /= Name_Value)
or else (Nkind (Maybe_Aspect_Spec) = N_Aspect_Specification
and then Get_Aspect_Id (Maybe_Aspect_Spec)
-- Include aspects that can be specified by a
-- subprogram name, which can be an operator.
in Aspect_Stable_Properties
| Aspect_Integer_Literal
| Aspect_Real_Literal
| Aspect_String_Literal
| Aspect_Aggregate)
then
Find_Direct_Name (N);
else
Change_Operator_Symbol_To_String_Literal (N);
Analyze (N);
end if;
end Analyze_Operator_Symbol;
-----------------------------------
-- Analyze_Parameter_Association --
-----------------------------------
procedure Analyze_Parameter_Association (N : Node_Id) is
begin
Analyze (Explicit_Actual_Parameter (N));
end Analyze_Parameter_Association;
----------------------------
-- Analyze_Procedure_Call --
----------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos that jump to the end of the routine and restore the
-- Ghost mode.
procedure Analyze_Procedure_Call (N : Node_Id) is
procedure Analyze_Call_And_Resolve;
-- Do Analyze and Resolve calls for procedure call. At the end, check
-- for illegal order dependence.
-- ??? where is the check for illegal order dependencies?
------------------------------
-- Analyze_Call_And_Resolve --
------------------------------
procedure Analyze_Call_And_Resolve is
begin
if Nkind (N) = N_Procedure_Call_Statement then
Analyze_Call (N);
Resolve (N, Standard_Void_Type);
else
Analyze (N);
end if;
end Analyze_Call_And_Resolve;
-- Local variables
Actuals : constant List_Id := Parameter_Associations (N);
Loc : constant Source_Ptr := Sloc (N);
P : constant Node_Id := Name (N);
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
Actual : Node_Id;
New_N : Node_Id;
-- Start of processing for Analyze_Procedure_Call
begin
-- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
-- a procedure call or an entry call. The prefix may denote an access
-- to subprogram type, in which case an implicit dereference applies.
-- If the prefix is an indexed component (without implicit dereference)
-- then the construct denotes a call to a member of an entire family.
-- If the prefix is a simple name, it may still denote a call to a
-- parameterless member of an entry family. Resolution of these various
-- interpretations is delicate.
-- Do not analyze machine code statements to avoid rejecting them in
-- CodePeer mode.
if CodePeer_Mode and then Nkind (P) = N_Qualified_Expression then
Set_Etype (P, Standard_Void_Type);
else
Analyze (P);
end if;
-- If this is a call of the form Obj.Op, the call may have been analyzed
-- and possibly rewritten into a block, in which case we are done.
if Analyzed (N) then
return;
-- If there is an error analyzing the name (which may have been
-- rewritten if the original call was in prefix notation) then error
-- has been emitted already, mark node and return.
elsif Error_Posted (N) or else Etype (Name (N)) = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- A procedure call is Ghost when its name denotes a Ghost procedure.
-- Set the mode now to ensure that any nodes generated during analysis
-- and expansion are properly marked as Ghost.
Mark_And_Set_Ghost_Procedure_Call (N);
-- Otherwise analyze the parameters
if Present (Actuals) then
Actual := First (Actuals);
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
Next (Actual);
end loop;
end if;
-- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls
if Nkind (P) = N_Attribute_Reference
and then Attribute_Name (P) in Name_Elab_Spec
| Name_Elab_Body
| Name_Elab_Subp_Body
then
if Present (Actuals) then
Error_Msg_N
("no parameters allowed for this call", First (Actuals));
goto Leave;
end if;
Set_Etype (N, Standard_Void_Type);
Set_Analyzed (N);
elsif Is_Entity_Name (P)
and then Is_Record_Type (Etype (Entity (P)))
and then Remote_AST_I_Dereference (P)
then
goto Leave;
elsif Is_Entity_Name (P)
and then Ekind (Entity (P)) /= E_Entry_Family
then
if Is_Access_Type (Etype (P))
and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
and then No (Actuals)
and then Comes_From_Source (N)
then
Error_Msg_N ("missing explicit dereference in call", N);
elsif Ekind (Entity (P)) = E_Operator then
Error_Msg_Name_1 := Chars (P);
Error_Msg_N ("operator % cannot be used as a procedure", N);
end if;
Analyze_Call_And_Resolve;
-- If the prefix is the simple name of an entry family, this is a
-- parameterless call from within the task body itself.
elsif Is_Entity_Name (P)
and then Nkind (P) = N_Identifier
and then Ekind (Entity (P)) = E_Entry_Family
and then Present (Actuals)
and then No (Next (First (Actuals)))
then
-- Can be call to parameterless entry family. What appears to be the
-- sole argument is in fact the entry index. Rewrite prefix of node
-- accordingly. Source representation is unchanged by this
-- transformation.
New_N :=
Make_Indexed_Component (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
Expressions => Actuals);
Set_Name (N, New_N);
Set_Etype (New_N, Standard_Void_Type);
Set_Parameter_Associations (N, No_List);
Analyze_Call_And_Resolve;
elsif Nkind (P) = N_Explicit_Dereference then
if Ekind (Etype (P)) = E_Subprogram_Type then
Analyze_Call_And_Resolve;
else
Error_Msg_N ("expect access to procedure in call", P);
end if;
-- The name can be a selected component or an indexed component that
-- yields an access to subprogram. Such a prefix is legal if the call
-- has parameter associations.
elsif Is_Access_Type (Etype (P))
and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
then
if Present (Actuals) then
Analyze_Call_And_Resolve;
else
Error_Msg_N ("missing explicit dereference in call", N);
end if;
-- If not an access to subprogram, then the prefix must resolve to the
-- name of an entry, entry family, or protected operation.
-- For the case of a simple entry call, P is a selected component where
-- the prefix is the task and the selector name is the entry. A call to
-- a protected procedure will have the same syntax. If the protected
-- object contains overloaded operations, the entity may appear as a
-- function, the context will select the operation whose type is Void.
elsif Nkind (P) = N_Selected_Component
and then Ekind (Entity (Selector_Name (P)))
in E_Entry | E_Function | E_Procedure
then
-- When front-end inlining is enabled, as with SPARK_Mode, a call
-- in prefix notation may still be missing its controlling argument,
-- so perform the transformation now.
if SPARK_Mode = On and then In_Inlined_Body then
declare
Subp : constant Entity_Id := Entity (Selector_Name (P));
Typ : constant Entity_Id := Etype (Prefix (P));
begin
if Is_Tagged_Type (Typ)
and then Present (First_Formal (Subp))
and then (Etype (First_Formal (Subp)) = Typ
or else
Class_Wide_Type (Etype (First_Formal (Subp))) = Typ)
and then Try_Object_Operation (P)
then
return;
else
Analyze_Call_And_Resolve;
end if;
end;
else
Analyze_Call_And_Resolve;
end if;
elsif Nkind (P) = N_Selected_Component
and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
and then Present (Actuals)
and then No (Next (First (Actuals)))
then
-- Can be call to parameterless entry family. What appears to be the
-- sole argument is in fact the entry index. Rewrite prefix of node
-- accordingly. Source representation is unchanged by this
-- transformation.
New_N :=
Make_Indexed_Component (Loc,
Prefix => New_Copy (P),
Expressions => Actuals);
Set_Name (N, New_N);
Set_Etype (New_N, Standard_Void_Type);
Set_Parameter_Associations (N, No_List);
Analyze_Call_And_Resolve;
-- For the case of a reference to an element of an entry family, P is
-- an indexed component whose prefix is a selected component (task and
-- entry family), and whose index is the entry family index.
elsif Nkind (P) = N_Indexed_Component
and then Nkind (Prefix (P)) = N_Selected_Component
and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
then
Analyze_Call_And_Resolve;
-- If the prefix is the name of an entry family, it is a call from
-- within the task body itself.
elsif Nkind (P) = N_Indexed_Component
and then Nkind (Prefix (P)) = N_Identifier
and then Ekind (Entity (Prefix (P))) = E_Entry_Family
then
New_N :=
Make_Selected_Component (Loc,
Prefix =>
New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
Rewrite (Prefix (P), New_N);
Analyze (P);
Analyze_Call_And_Resolve;
-- In Ada 2012. a qualified expression is a name, but it cannot be a
-- procedure name, so the construct can only be a qualified expression.
elsif Nkind (P) = N_Qualified_Expression
and then Ada_Version >= Ada_2012
then
Rewrite (N, Make_Code_Statement (Loc, Expression => P));
Analyze (N);
-- Anything else is an error
else
Error_Msg_N ("invalid procedure or entry call", N);
-- Specialize the error message in the case where both a primitive
-- operation and a record component are visible at the same time.
if Nkind (P) = N_Selected_Component
and then Is_Entity_Name (Selector_Name (P))
then
declare
Sel : constant Entity_Id := Entity (Selector_Name (P));
begin
if Ekind (Sel) = E_Component
and then Present (Homonym (Sel))
and then Ekind (Homonym (Sel)) = E_Procedure
then
Error_Msg_NE ("\component & conflicts with"
& " homonym procedure (RM 4.1.3 (9.2/3))",
Selector_Name (P), Sel);
end if;
end;
end if;
end if;
<<Leave>>
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Analyze_Procedure_Call;
------------------------------
-- Analyze_Return_Statement --
------------------------------
procedure Analyze_Return_Statement (N : Node_Id) is
pragma Assert
(Nkind (N) in N_Extended_Return_Statement | N_Simple_Return_Statement);
Returns_Object : constant Boolean :=
Nkind (N) = N_Extended_Return_Statement
or else
(Nkind (N) = N_Simple_Return_Statement
and then Present (Expression (N)));
-- True if we're returning something; that is, "return <expression>;"
-- or "return Result : T [:= ...]". False for "return;". Used for error
-- checking: If Returns_Object is True, N should apply to a function
-- body; otherwise N should apply to a procedure body, entry body,
-- accept statement, or extended return statement.
function Find_What_It_Applies_To return Entity_Id;
-- Find the entity representing the innermost enclosing body, accept
-- statement, or extended return statement. If the result is a callable
-- construct or extended return statement, then this will be the value
-- of the Return_Applies_To attribute. Otherwise, the program is
-- illegal. See RM-6.5(4/2).
-----------------------------
-- Find_What_It_Applies_To --
-----------------------------
function Find_What_It_Applies_To return Entity_Id is
Result : Entity_Id := Empty;
begin
-- Loop outward through the Scope_Stack, skipping blocks, and loops
for J in reverse 0 .. Scope_Stack.Last loop
Result := Scope_Stack.Table (J).Entity;
exit when Ekind (Result) not in E_Block | E_Loop;
end loop;
pragma Assert (Present (Result));
return Result;
end Find_What_It_Applies_To;
-- Local declarations
Scope_Id : constant Entity_Id := Find_What_It_Applies_To;
Kind : constant Entity_Kind := Ekind (Scope_Id);
Loc : constant Source_Ptr := Sloc (N);
Stm_Entity : constant Entity_Id :=
New_Internal_Entity
(E_Return_Statement, Current_Scope, Loc, 'R');
-- Start of processing for Analyze_Return_Statement
begin
Set_Return_Statement_Entity (N, Stm_Entity);
Set_Etype (Stm_Entity, Standard_Void_Type);
Set_Return_Applies_To (Stm_Entity, Scope_Id);
-- Place Return entity on scope stack, to simplify enforcement of 6.5
-- (4/2): an inner return statement will apply to this extended return.
if Nkind (N) = N_Extended_Return_Statement then
Push_Scope (Stm_Entity);
end if;
-- Check that pragma No_Return is obeyed. Don't complain about the
-- implicitly-generated return that is placed at the end.
if No_Return (Scope_Id)
and then Kind in E_Procedure | E_Generic_Procedure
and then Comes_From_Source (N)
then
Error_Msg_N
("RETURN statement not allowed in No_Return procedure", N);
end if;
-- Warn on any unassigned OUT parameters if in procedure
if Ekind (Scope_Id) = E_Procedure then
Warn_On_Unassigned_Out_Parameter (N, Scope_Id);
end if;
-- Check that functions return objects, and other things do not
if Kind in E_Function | E_Generic_Function then
if not Returns_Object then
Error_Msg_N ("missing expression in return from function", N);
end if;
elsif Kind in E_Procedure | E_Generic_Procedure then
if Returns_Object then
Error_Msg_N ("procedure cannot return value (use function)", N);
end if;
elsif Kind in E_Entry | E_Entry_Family then
if Returns_Object then
if Is_Protected_Type (Scope (Scope_Id)) then
Error_Msg_N ("entry body cannot return value", N);
else
Error_Msg_N ("accept statement cannot return value", N);
end if;
end if;
elsif Kind = E_Return_Statement then
-- We are nested within another return statement, which must be an
-- extended_return_statement.
if Returns_Object then
if Nkind (N) = N_Extended_Return_Statement then
Error_Msg_N
("extended return statement cannot be nested (use `RETURN;`)",
N);
-- Case of a simple return statement with a value inside extended
-- return statement.
else
Error_Msg_N
("return nested in extended return statement cannot return "
& "value (use `RETURN;`)", N);
end if;
end if;
else
Error_Msg_N ("illegal context for return statement", N);
end if;
if Kind in E_Function | E_Generic_Function then
Analyze_Function_Return (N);
elsif Kind in E_Procedure | E_Generic_Procedure then
Set_Return_Present (Scope_Id);
end if;
if Nkind (N) = N_Extended_Return_Statement then
End_Scope;
end if;
Kill_Current_Values (Last_Assignment_Only => True);
Check_Unreachable_Code (N);
Analyze_Dimension (N);
end Analyze_Return_Statement;
-----------------------------------
-- Analyze_Return_When_Statement --
-----------------------------------
procedure Analyze_Return_When_Statement (N : Node_Id) is
begin
-- Verify the condition is a Boolean expression
Analyze_And_Resolve (Condition (N), Any_Boolean);
Check_Unset_Reference (Condition (N));
end Analyze_Return_When_Statement;
-------------------------------------
-- Analyze_Simple_Return_Statement --
-------------------------------------
procedure Analyze_Simple_Return_Statement (N : Node_Id) is
begin
if Present (Expression (N)) then
Mark_Coextensions (N, Expression (N));
end if;
Analyze_Return_Statement (N);
end Analyze_Simple_Return_Statement;
-------------------------
-- Analyze_Return_Type --
-------------------------
procedure Analyze_Return_Type (N : Node_Id) is
Designator : constant Entity_Id := Defining_Entity (N);
Typ : Entity_Id := Empty;
begin
-- Normal case where result definition does not indicate an error
if Result_Definition (N) /= Error then
if Nkind (Result_Definition (N)) = N_Access_Definition then
-- Ada 2005 (AI-254): Handle anonymous access to subprograms
declare
AD : constant Node_Id :=
Access_To_Subprogram_Definition (Result_Definition (N));
begin
if Present (AD) and then Protected_Present (AD) then
Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N);
else
Typ := Access_Definition (N, Result_Definition (N));
end if;
end;
Set_Parent (Typ, Result_Definition (N));
Set_Is_Local_Anonymous_Access (Typ);
Set_Etype (Designator, Typ);
-- Ada 2005 (AI-231): Ensure proper usage of null exclusion
Null_Exclusion_Static_Checks (N);
-- Subtype_Mark case
else
Find_Type (Result_Definition (N));
Typ := Entity (Result_Definition (N));
Set_Etype (Designator, Typ);
-- Ada 2005 (AI-231): Ensure proper usage of null exclusion
Null_Exclusion_Static_Checks (N);
-- If a null exclusion is imposed on the result type, then create
-- a null-excluding itype (an access subtype) and use it as the
-- function's Etype. Note that the null exclusion checks are done
-- right before this, because they don't get applied to types that
-- do not come from source.
if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then
Set_Etype (Designator,
Create_Null_Excluding_Itype
(T => Typ,
Related_Nod => N,
Scope_Id => Scope (Current_Scope)));
-- The new subtype must be elaborated before use because
-- it is visible outside of the function. However its base
-- type may not be frozen yet, so the reference that will
-- force elaboration must be attached to the freezing of
-- the base type.
-- If the return specification appears on a proper body,
-- the subtype will have been created already on the spec.
if Is_Frozen (Typ) then
if Nkind (Parent (N)) = N_Subprogram_Body
and then Nkind (Parent (Parent (N))) = N_Subunit
then
null;
else
Build_Itype_Reference (Etype (Designator), Parent (N));
end if;
else
Ensure_Freeze_Node (Typ);
declare
IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
begin
Set_Itype (IR, Etype (Designator));
Append_Freeze_Actions (Typ, New_List (IR));
end;
end if;
else
Set_Etype (Designator, Typ);
end if;
if Ekind (Typ) = E_Incomplete_Type
or else (Is_Class_Wide_Type (Typ)
and then Ekind (Root_Type (Typ)) = E_Incomplete_Type)
then
-- AI05-0151: Tagged incomplete types are allowed in all formal
-- parts. Untagged incomplete types are not allowed in bodies.
-- As a consequence, limited views cannot appear in a basic
-- declaration that is itself within a body, because there is
-- no point at which the non-limited view will become visible.
if Ada_Version >= Ada_2012 then
if From_Limited_With (Typ) and then In_Package_Body then
Error_Msg_NE
("invalid use of incomplete type&",
Result_Definition (N), Typ);
-- The return type of a subprogram body cannot be of a
-- formal incomplete type.
elsif Is_Generic_Type (Typ)
and then Nkind (Parent (N)) = N_Subprogram_Body
then
Error_Msg_N
("return type cannot be a formal incomplete type",
Result_Definition (N));
elsif Is_Class_Wide_Type (Typ)
and then Is_Generic_Type (Root_Type (Typ))
and then Nkind (Parent (N)) = N_Subprogram_Body
then
Error_Msg_N
("return type cannot be a formal incomplete type",
Result_Definition (N));
elsif Is_Tagged_Type (Typ) then
null;
-- Use is legal in a thunk generated for an operation
-- inherited from a progenitor.
elsif Is_Thunk (Designator)
and then Present (Non_Limited_View (Typ))
then
null;
elsif Nkind (Parent (N)) = N_Subprogram_Body
or else Nkind (Parent (Parent (N))) in
N_Accept_Statement | N_Entry_Body
then
Error_Msg_NE
("invalid use of untagged incomplete type&",
Designator, Typ);
end if;
-- The type must be completed in the current package. This
-- is checked at the end of the package declaration when
-- Taft-amendment types are identified. If the return type
-- is class-wide, there is no required check, the type can
-- be a bona fide TAT.
if Ekind (Scope (Current_Scope)) = E_Package
and then In_Private_Part (Scope (Current_Scope))
and then not Is_Class_Wide_Type (Typ)
then
Append_Elmt (Designator, Private_Dependents (Typ));
end if;
else
Error_Msg_NE
("invalid use of incomplete type&", Designator, Typ);
end if;
end if;
end if;
-- Case where result definition does indicate an error
else
Set_Etype (Designator, Any_Type);
end if;
end Analyze_Return_Type;
-----------------------------
-- Analyze_Subprogram_Body --
-----------------------------
procedure Analyze_Subprogram_Body (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Body_Spec : constant Node_Id := Specification (N);
Body_Id : constant Entity_Id := Defining_Entity (Body_Spec);
begin
if Debug_Flag_C then
Write_Str ("==> subprogram body ");
Write_Name (Chars (Body_Id));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
Indent;
end if;
Trace_Scope (N, Body_Id, " Analyze subprogram: ");
-- The real work is split out into the helper, so it can do "return;"
-- without skipping the debug output:
Analyze_Subprogram_Body_Helper (N);
if Debug_Flag_C then
Outdent;
Write_Str ("<== subprogram body ");
Write_Name (Chars (Body_Id));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
end if;
end Analyze_Subprogram_Body;
------------------------------------
-- Analyze_Subprogram_Body_Helper --
------------------------------------
-- This procedure is called for regular subprogram bodies, generic bodies,
-- and for subprogram stubs of both kinds. In the case of stubs, only the
-- specification matters, and is used to create a proper declaration for
-- the subprogram, or to perform conformance checks.
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos that jump to the end of the routine and restore the
-- Ghost mode.
procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is
Body_Spec : Node_Id := Specification (N);
Body_Id : Entity_Id := Defining_Entity (Body_Spec);
Loc : constant Source_Ptr := Sloc (N);
Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
Body_Nod : Node_Id := Empty;
Minimum_Acc_Objs : List_Id := No_List;
Conformant : Boolean;
Desig_View : Entity_Id := Empty;
Exch_Views : Elist_Id := No_Elist;
HSS : Node_Id;
Mask_Types : Elist_Id := No_Elist;
Prot_Typ : Entity_Id := Empty;
Spec_Decl : Node_Id := Empty;
Spec_Id : Entity_Id;
Last_Real_Spec_Entity : Entity_Id := Empty;
-- When we analyze a separate spec, the entity chain ends up containing
-- the formals, as well as any itypes generated during analysis of the
-- default expressions for parameters, or the arguments of associated
-- precondition/postcondition pragmas (which are analyzed in the context
-- of the spec since they have visibility on formals).
--
-- These entities belong with the spec and not the body. However we do
-- the analysis of the body in the context of the spec (again to obtain
-- visibility to the formals), and all the entities generated during
-- this analysis end up also chained to the entity chain of the spec.
-- But they really belong to the body, and there is circuitry to move
-- them from the spec to the body.
--
-- However, when we do this move, we don't want to move the real spec
-- entities (first para above) to the body. The Last_Real_Spec_Entity
-- variable points to the last real spec entity, so we only move those
-- chained beyond that point. It is initialized to Empty to deal with
-- the case where there is no separate spec.
function Body_Has_Contract return Boolean;
-- Check whether unanalyzed body has an aspect or pragma that may
-- generate a SPARK contract.
function Body_Has_SPARK_Mode_On return Boolean;
-- Check whether SPARK_Mode On applies to the subprogram body, either
-- because it is specified directly on the body, or because it is
-- inherited from the enclosing subprogram or package.
function Build_Internal_Protected_Declaration
(N : Node_Id) return Entity_Id;
-- A subprogram body without a previous spec that appears in a protected
-- body must be expanded separately to create a subprogram declaration
-- for it, in order to resolve internal calls to it from other protected
-- operations.
--
-- Possibly factor this with Exp_Dist.Copy_Specification ???
procedure Build_Subprogram_Declaration;
-- Create a matching subprogram declaration for subprogram body N
procedure Check_Anonymous_Return;
-- Ada 2005: if a function returns an access type that denotes a task,
-- or a type that contains tasks, we must create a master entity for
-- the anonymous type, which typically will be used in an allocator
-- in the body of the function.
procedure Check_Inline_Pragma (Spec : in out Node_Id);
-- Look ahead to recognize a pragma that may appear after the body.
-- If there is a previous spec, check that it appears in the same
-- declarative part. If the pragma is Inline_Always, perform inlining
-- unconditionally, otherwise only if Front_End_Inlining is requested.
-- If the body acts as a spec, and inlining is required, we create a
-- subprogram declaration for it, in order to attach the body to inline.
-- If pragma does not appear after the body, check whether there is
-- an inline pragma before any local declarations.
procedure Check_Missing_Return;
-- Checks for a function with a no return statements, and also performs
-- the warning checks implemented by Check_Returns. In formal mode, also
-- verify that a function ends with a RETURN and that a procedure does
-- not contain any RETURN.
function Disambiguate_Spec return Entity_Id;
-- When a primitive is declared between the private view and the full
-- view of a concurrent type which implements an interface, a special
-- mechanism is used to find the corresponding spec of the primitive
-- body.
function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id;
-- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains
-- incomplete types coming from a limited context and replace their
-- limited views with the non-limited ones. Return the list of changes
-- to be used to undo the transformation.
procedure Generate_Minimum_Accessibility
(Extra_Access : Entity_Id;
Related_Form : Entity_Id := Empty);
-- Generate a minimum accessibility object for a given extra
-- accessibility formal (Extra_Access) and its related formal if it
-- exists.
function Is_Private_Concurrent_Primitive
(Subp_Id : Entity_Id) return Boolean;
-- Determine whether subprogram Subp_Id is a primitive of a concurrent
-- type that implements an interface and has a private view.
function Mask_Unfrozen_Types (Spec_Id : Entity_Id) return Elist_Id;
-- N is the body generated for an expression function that is not a
-- completion and Spec_Id the defining entity of its spec. Mark all
-- the not-yet-frozen types referenced by the simple return statement
-- of the function as formally frozen.
procedure Move_Pragmas (From : Node_Id; To : Node_Id);
-- Find all suitable source pragmas at the top of subprogram body
-- From's declarations and move them after arbitrary node To.
-- One exception is pragma SPARK_Mode which is copied rather than moved,
-- as it applies to the body too.
procedure Restore_Limited_Views (Restore_List : Elist_Id);
-- Undo the transformation done by Exchange_Limited_Views.
procedure Set_Trivial_Subprogram (N : Node_Id);
-- Sets the Is_Trivial_Subprogram flag in both spec and body of the
-- subprogram whose body is being analyzed. N is the statement node
-- causing the flag to be set, if the following statement is a return
-- of an entity, we mark the entity as set in source to suppress any
-- warning on the stylized use of function stubs with a dummy return.
procedure Unmask_Unfrozen_Types (Unmask_List : Elist_Id);
-- Undo the transformation done by Mask_Unfrozen_Types
procedure Verify_Overriding_Indicator;
-- If there was a previous spec, the entity has been entered in the
-- current scope previously. If the body itself carries an overriding
-- indicator, check that it is consistent with the known status of the
-- entity.
-----------------------
-- Body_Has_Contract --
-----------------------
function Body_Has_Contract return Boolean is
Decls : constant List_Id := Declarations (N);
Item : Node_Id;
begin
-- Check for aspects that may generate a contract
if Present (Aspect_Specifications (N)) then
Item := First (Aspect_Specifications (N));
while Present (Item) loop
if Is_Subprogram_Contract_Annotation (Item) then
return True;
end if;
Next (Item);
end loop;
end if;
-- Check for pragmas that may generate a contract
if Present (Decls) then
Item := First (Decls);
while Present (Item) loop
if Nkind (Item) = N_Pragma
and then Is_Subprogram_Contract_Annotation (Item)
then
return True;
end if;
Next (Item);
end loop;
end if;
return False;
end Body_Has_Contract;
----------------------------
-- Body_Has_SPARK_Mode_On --
----------------------------
function Body_Has_SPARK_Mode_On return Boolean is
Decls : constant List_Id := Declarations (N);
Item : Node_Id;
begin
-- Check for SPARK_Mode aspect
if Present (Aspect_Specifications (N)) then
Item := First (Aspect_Specifications (N));
while Present (Item) loop
if Get_Aspect_Id (Item) = Aspect_SPARK_Mode then
return Get_SPARK_Mode_From_Annotation (Item) = On;
end if;
Next (Item);
end loop;
end if;
-- Check for SPARK_Mode pragma
if Present (Decls) then
Item := First (Decls);
while Present (Item) loop
-- Pragmas that apply to a subprogram body are usually grouped
-- together. Look for a potential pragma SPARK_Mode among them.
if Nkind (Item) = N_Pragma then
if Get_Pragma_Id (Item) = Pragma_SPARK_Mode then
return Get_SPARK_Mode_From_Annotation (Item) = On;
end if;
-- Otherwise the first non-pragma declarative item terminates
-- the region where pragma SPARK_Mode may appear.
else
exit;
end if;
Next (Item);
end loop;
end if;
-- Otherwise, the applicable SPARK_Mode is inherited from the
-- enclosing subprogram or package.
return SPARK_Mode = On;
end Body_Has_SPARK_Mode_On;
------------------------------------------
-- Build_Internal_Protected_Declaration --
------------------------------------------
function Build_Internal_Protected_Declaration
(N : Node_Id) return Entity_Id
is
procedure Analyze_Pragmas (From : Node_Id);
-- Analyze all pragmas which follow arbitrary node From
---------------------
-- Analyze_Pragmas --
---------------------
procedure Analyze_Pragmas (From : Node_Id) is
Decl : Node_Id;
begin
Decl := Next (From);
while Present (Decl) loop
if Nkind (Decl) = N_Pragma then
Analyze_Pragma (Decl);
-- No candidate pragmas are available for analysis
else
exit;
end if;
Next (Decl);
end loop;
end Analyze_Pragmas;
-- Local variables
Body_Id : constant Entity_Id := Defining_Entity (N);
Loc : constant Source_Ptr := Sloc (N);
Decl : Node_Id;
Formal : Entity_Id;
Formals : List_Id;
Spec : Node_Id;
Spec_Id : Entity_Id;
-- Start of processing for Build_Internal_Protected_Declaration
begin
Formal := First_Formal (Body_Id);
-- The protected operation always has at least one formal, namely the
-- object itself, but it is only placed in the parameter list if
-- expansion is enabled.
if Present (Formal) or else Expander_Active then
Formals := Copy_Parameter_List (Body_Id);
else
Formals := No_List;
end if;
Spec_Id :=
Make_Defining_Identifier (Sloc (Body_Id),
Chars => Chars (Body_Id));
-- Indicate that the entity comes from source, to ensure that cross-
-- reference information is properly generated. The body itself is
-- rewritten during expansion, and the body entity will not appear in
-- calls to the operation.
Set_Comes_From_Source (Spec_Id, True);
if Nkind (Specification (N)) = N_Procedure_Specification then
Spec :=
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Spec_Id,
Parameter_Specifications => Formals);
else
Spec :=
Make_Function_Specification (Loc,
Defining_Unit_Name => Spec_Id,
Parameter_Specifications => Formals,
Result_Definition =>
New_Occurrence_Of (Etype (Body_Id), Loc));
end if;
Decl := Make_Subprogram_Declaration (Loc, Specification => Spec);
Set_Corresponding_Body (Decl, Body_Id);
Set_Corresponding_Spec (N, Spec_Id);
Insert_Before (N, Decl);
-- Associate all aspects and pragmas of the body with the spec. This
-- ensures that these annotations apply to the initial declaration of
-- the subprogram body.
Move_Aspects (From => N, To => Decl);
Move_Pragmas (From => N, To => Decl);
Analyze (Decl);
-- The analysis of the spec may generate pragmas which require manual
-- analysis. Since the generation of the spec and the relocation of
-- the annotations is driven by the expansion of the stand-alone
-- body, the pragmas will not be analyzed in a timely manner. Do this
-- now.
Analyze_Pragmas (Decl);
-- This subprogram has convention Intrinsic as per RM 6.3.1(10/2)
-- ensuring in particular that 'Access is illegal.
Set_Convention (Spec_Id, Convention_Intrinsic);
Set_Has_Completion (Spec_Id);
return Spec_Id;
end Build_Internal_Protected_Declaration;
----------------------------------
-- Build_Subprogram_Declaration --
----------------------------------
procedure Build_Subprogram_Declaration is
Decl : Node_Id;
Subp_Decl : Node_Id;
begin
-- Create a matching subprogram spec using the profile of the body.
-- The structure of the tree is identical, but has new entities for
-- the defining unit name and formal parameters.
Subp_Decl :=
Make_Subprogram_Declaration (Loc,
Specification => Copy_Subprogram_Spec (Body_Spec));
Set_Comes_From_Source (Subp_Decl, True);
-- Also mark parameters as coming from source
if Present (Parameter_Specifications (Specification (Subp_Decl))) then
declare
Form : Entity_Id;
begin
Form :=
First (Parameter_Specifications (Specification (Subp_Decl)));
while Present (Form) loop
Set_Comes_From_Source (Defining_Identifier (Form), True);
Next (Form);
end loop;
end;
end if;
-- Relocate the aspects and relevant pragmas from the subprogram body
-- to the generated spec because it acts as the initial declaration.
Insert_Before (N, Subp_Decl);
Move_Aspects (N, To => Subp_Decl);
Move_Pragmas (N, To => Subp_Decl);
-- Ensure that the generated corresponding spec and original body
-- share the same SPARK_Mode pragma or aspect. As a result, both have
-- the same SPARK_Mode attributes, and the global SPARK_Mode value is
-- correctly set for local subprograms.
Copy_SPARK_Mode_Aspect (Subp_Decl, To => N);
Analyze (Subp_Decl);
-- Propagate the attributes Rewritten_For_C and Corresponding_Proc to
-- the body since the expander may generate calls using that entity.
-- Required to ensure that Expand_Call rewrites calls to this
-- function by calls to the built procedure.
if Transform_Function_Array
and then Nkind (Body_Spec) = N_Function_Specification
and then
Rewritten_For_C (Defining_Entity (Specification (Subp_Decl)))
then
Set_Rewritten_For_C (Defining_Entity (Body_Spec));
Set_Corresponding_Procedure (Defining_Entity (Body_Spec),
Corresponding_Procedure
(Defining_Entity (Specification (Subp_Decl))));
end if;
-- Analyze any relocated source pragmas or pragmas created for aspect
-- specifications.
Decl := Next (Subp_Decl);
while Present (Decl) loop
-- Stop the search for pragmas once the body has been reached as
-- this terminates the region where pragmas may appear.
if Decl = N then
exit;
elsif Nkind (Decl) = N_Pragma then
Analyze (Decl);
end if;
Next (Decl);
end loop;
Spec_Id := Defining_Entity (Subp_Decl);
Set_Corresponding_Spec (N, Spec_Id);
-- Mark the generated spec as a source construct to ensure that all
-- calls to it are properly registered in ALI files for GNATprove.
Set_Comes_From_Source (Spec_Id, True);
-- Ensure that the specs of the subprogram declaration and its body
-- are identical, otherwise they will appear non-conformant due to
-- rewritings in the default values of formal parameters.
Body_Spec := Copy_Subprogram_Spec (Body_Spec);
Set_Specification (N, Body_Spec);
Body_Id := Analyze_Subprogram_Specification (Body_Spec);
end Build_Subprogram_Declaration;
----------------------------
-- Check_Anonymous_Return --
----------------------------
procedure Check_Anonymous_Return is
Decl : Node_Id;
Par : Node_Id;
Scop : Entity_Id;
begin
if Present (Spec_Id) then
Scop := Spec_Id;
else
Scop := Body_Id;
end if;
if Ekind (Scop) = E_Function
and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type
and then not Is_Thunk (Scop)
-- Skip internally built functions which handle the case of
-- a null access (see Expand_Interface_Conversion)
and then not (Is_Interface (Designated_Type (Etype (Scop)))
and then not Comes_From_Source (Parent (Scop)))
and then (Has_Task (Designated_Type (Etype (Scop)))
or else
(Is_Class_Wide_Type (Designated_Type (Etype (Scop)))
and then
Is_Limited_Record (Designated_Type (Etype (Scop)))))
and then Expander_Active
then
Decl := Build_Master_Declaration (Loc);
if Present (Declarations (N)) then
Prepend (Decl, Declarations (N));
else
Set_Declarations (N, New_List (Decl));
end if;
Set_Master_Id (Etype (Scop), Defining_Identifier (Decl));
Set_Has_Master_Entity (Scop);
-- Now mark the containing scope as a task master
Par := N;
while Nkind (Par) /= N_Compilation_Unit loop
Par := Parent (Par);
pragma Assert (Present (Par));
-- If we fall off the top, we are at the outer level, and
-- the environment task is our effective master, so nothing
-- to mark.
if Nkind (Par)
in N_Task_Body | N_Block_Statement | N_Subprogram_Body
then
Set_Is_Task_Master (Par, True);
exit;
end if;
end loop;
end if;
end Check_Anonymous_Return;
-------------------------
-- Check_Inline_Pragma --
-------------------------
procedure Check_Inline_Pragma (Spec : in out Node_Id) is
Prag : Node_Id;
Plist : List_Id;
function Is_Inline_Pragma (N : Node_Id) return Boolean;
-- True when N is a pragma Inline or Inline_Always that applies
-- to this subprogram.
-----------------------
-- Is_Inline_Pragma --
-----------------------
function Is_Inline_Pragma (N : Node_Id) return Boolean is
begin
if Nkind (N) = N_Pragma
and then
(Pragma_Name_Unmapped (N) = Name_Inline_Always
or else (Pragma_Name_Unmapped (N) = Name_Inline
and then
(Front_End_Inlining or else Optimization_Level > 0)))
and then Present (Pragma_Argument_Associations (N))
then
declare
Pragma_Arg : Node_Id :=
Expression (First (Pragma_Argument_Associations (N)));
begin
if Nkind (Pragma_Arg) = N_Selected_Component then
Pragma_Arg := Selector_Name (Pragma_Arg);
end if;
return Chars (Pragma_Arg) = Chars (Body_Id);
end;
else
return False;
end if;
end Is_Inline_Pragma;
-- Start of processing for Check_Inline_Pragma
begin
if not Expander_Active then
return;
end if;
if Is_List_Member (N)
and then Present (Next (N))
and then Is_Inline_Pragma (Next (N))
then
Prag := Next (N);
elsif Nkind (N) /= N_Subprogram_Body_Stub
and then Present (Declarations (N))
and then Is_Inline_Pragma (First (Declarations (N)))
then
Prag := First (Declarations (N));
else
Prag := Empty;
end if;
if Present (Prag) and then Is_List_Member (N) then
if Present (Spec_Id) then
if Is_List_Member (Unit_Declaration_Node (Spec_Id))
and then In_Same_List (N, Unit_Declaration_Node (Spec_Id))
then
Analyze (Prag);
end if;
else
-- Create a subprogram declaration, to make treatment uniform.
-- Make the sloc of the subprogram name that of the entity in
-- the body, so that style checks find identical strings.
declare
Subp : constant Entity_Id :=
Make_Defining_Identifier
(Sloc (Body_Id), Chars (Body_Id));
Decl : constant Node_Id :=
Make_Subprogram_Declaration (Loc,
Specification =>
New_Copy_Tree (Specification (N)));
begin
-- Link the body and the generated spec
Set_Corresponding_Body (Decl, Body_Id);
if Nkind (N) = N_Subprogram_Body_Stub then
Set_Corresponding_Spec_Of_Stub (N, Subp);
else
Set_Corresponding_Spec (N, Subp);
end if;
Set_Defining_Unit_Name (Specification (Decl), Subp);
-- To ensure proper coverage when body is inlined, indicate
-- whether the subprogram comes from source.
Preserve_Comes_From_Source (Subp, N);
if Present (First_Formal (Body_Id)) then
Plist := Copy_Parameter_List (Body_Id);
Set_Parameter_Specifications
(Specification (Decl), Plist);
end if;
-- Move aspects to the new spec
if Has_Aspects (N) then
Move_Aspects (N, To => Decl);
end if;
Insert_Before (N, Decl);
Analyze (Decl);
Analyze (Prag);
Set_Has_Pragma_Inline (Subp);
if Pragma_Name (Prag) = Name_Inline_Always then
Set_Is_Inlined (Subp);
Set_Has_Pragma_Inline_Always (Subp);
end if;
-- Prior to copying the subprogram body to create a template
-- for it for subsequent inlining, remove the pragma from
-- the current body so that the copy that will produce the
-- new body will start from a completely unanalyzed tree.
if Nkind (Parent (Prag)) = N_Subprogram_Body then
Rewrite (Prag, Make_Null_Statement (Sloc (Prag)));
end if;
Spec := Subp;
end;
end if;
end if;
end Check_Inline_Pragma;
--------------------------
-- Check_Missing_Return --
--------------------------
procedure Check_Missing_Return is
Id : Entity_Id;
Missing_Ret : Boolean;
begin
if Nkind (Body_Spec) = N_Function_Specification then
if Present (Spec_Id) then
Id := Spec_Id;
else
Id := Body_Id;
end if;
if Return_Present (Id) then
Check_Returns (HSS, 'F', Missing_Ret);
if Missing_Ret then
Set_Has_Missing_Return (Id);
end if;
-- Within a premature instantiation of a package with no body, we
-- build completions of the functions therein, with a Raise
-- statement. No point in complaining about a missing return in
-- this case.
elsif Ekind (Id) = E_Function
and then In_Instance
and then Present (Statements (HSS))
and then Nkind (First (Statements (HSS))) = N_Raise_Program_Error
then
null;
elsif Is_Generic_Subprogram (Id)
or else not Is_Machine_Code_Subprogram (Id)
then
Error_Msg_N ("missing RETURN statement in function body", N);
end if;
-- If procedure with No_Return, check returns
elsif Nkind (Body_Spec) = N_Procedure_Specification then
if Present (Spec_Id) then
Id := Spec_Id;
else
Id := Body_Id;
end if;
if No_Return (Id) then
Check_Returns (HSS, 'P', Missing_Ret, Id);
end if;
end if;
end Check_Missing_Return;
-----------------------
-- Disambiguate_Spec --
-----------------------
function Disambiguate_Spec return Entity_Id is
Priv_Spec : Entity_Id;
Spec_N : Entity_Id;
procedure Replace_Types (To_Corresponding : Boolean);
-- Depending on the flag, replace the type of formal parameters of
-- Body_Id if it is a concurrent type implementing interfaces with
-- the corresponding record type or the other way around.
procedure Replace_Types (To_Corresponding : Boolean) is
Formal : Entity_Id;
Formal_Typ : Entity_Id;
begin
Formal := First_Formal (Body_Id);
while Present (Formal) loop
Formal_Typ := Etype (Formal);
if Is_Class_Wide_Type (Formal_Typ) then
Formal_Typ := Root_Type (Formal_Typ);
end if;
-- From concurrent type to corresponding record
if To_Corresponding then
if Is_Concurrent_Type (Formal_Typ)
and then Present (Corresponding_Record_Type (Formal_Typ))
and then
Present (Interfaces
(Corresponding_Record_Type (Formal_Typ)))
then
Set_Etype (Formal,
Corresponding_Record_Type (Formal_Typ));
end if;
-- From corresponding record to concurrent type
else
if Is_Concurrent_Record_Type (Formal_Typ)
and then Present (Interfaces (Formal_Typ))
then
Set_Etype (Formal,
Corresponding_Concurrent_Type (Formal_Typ));
end if;
end if;
Next_Formal (Formal);
end loop;
end Replace_Types;
-- Start of processing for Disambiguate_Spec
begin
-- Try to retrieve the specification of the body as is. All error
-- messages are suppressed because the body may not have a spec in
-- its current state.
Spec_N := Find_Corresponding_Spec (N, False);
-- It is possible that this is the body of a primitive declared
-- between a private and a full view of a concurrent type. The
-- controlling parameter of the spec carries the concurrent type,
-- not the corresponding record type as transformed by Analyze_
-- Subprogram_Specification. In such cases, we undo the change
-- made by the analysis of the specification and try to find the
-- spec again.
-- Note that wrappers already have their corresponding specs and
-- bodies set during their creation, so if the candidate spec is
-- a wrapper, then we definitely need to swap all types to their
-- original concurrent status.
if No (Spec_N)
or else Is_Primitive_Wrapper (Spec_N)
then
-- Restore all references of corresponding record types to the
-- original concurrent types.
Replace_Types (To_Corresponding => False);
Priv_Spec := Find_Corresponding_Spec (N, False);
-- The current body truly belongs to a primitive declared between
-- a private and a full view. We leave the modified body as is,
-- and return the true spec.
if Present (Priv_Spec)
and then Is_Private_Primitive (Priv_Spec)
then
return Priv_Spec;
end if;
-- In case that this is some sort of error, restore the original
-- state of the body.
Replace_Types (To_Corresponding => True);
end if;
return Spec_N;
end Disambiguate_Spec;
----------------------------
-- Exchange_Limited_Views --
----------------------------
function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id is
Result : Elist_Id := No_Elist;
procedure Detect_And_Exchange (Id : Entity_Id);
-- Determine whether Id's type denotes an incomplete type associated
-- with a limited with clause and exchange the limited view with the
-- non-limited one when available. Note that the non-limited view
-- may exist because of a with_clause in another unit in the context,
-- but cannot be used because the current view of the enclosing unit
-- is still a limited view.
-------------------------
-- Detect_And_Exchange --
-------------------------
procedure Detect_And_Exchange (Id : Entity_Id) is
Typ : constant Entity_Id := Etype (Id);
begin
if From_Limited_With (Typ)
and then Has_Non_Limited_View (Typ)
and then not From_Limited_With (Scope (Typ))
then
if No (Result) then
Result := New_Elmt_List;
end if;
Prepend_Elmt (Typ, Result);
Prepend_Elmt (Id, Result);
Set_Etype (Id, Non_Limited_View (Typ));
end if;
end Detect_And_Exchange;
-- Local variables
Formal : Entity_Id;
-- Start of processing for Exchange_Limited_Views
begin
-- Do not process subprogram bodies as they already use the non-
-- limited view of types.
if Ekind (Subp_Id) not in E_Function | E_Procedure then
return No_Elist;
end if;
-- Examine all formals and swap views when applicable
Formal := First_Formal (Subp_Id);
while Present (Formal) loop
Detect_And_Exchange (Formal);
Next_Formal (Formal);
end loop;
-- Process the return type of a function
if Ekind (Subp_Id) = E_Function then
Detect_And_Exchange (Subp_Id);
end if;
return Result;
end Exchange_Limited_Views;
------------------------------------
-- Generate_Minimum_Accessibility --
------------------------------------
procedure Generate_Minimum_Accessibility
(Extra_Access : Entity_Id;
Related_Form : Entity_Id := Empty)
is
Loc : constant Source_Ptr := Sloc (Body_Nod);
Form : Entity_Id;
Obj_Node : Node_Id;
begin
-- When no related formal exists then we are dealing with an
-- extra accessibility formal for a function result.
if No (Related_Form) then
Form := Extra_Access;
else
Form := Related_Form;
end if;
-- Create the minimum accessibility object
Obj_Node :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Temporary
(Loc, 'A', Extra_Access),
Object_Definition => New_Occurrence_Of
(Standard_Natural, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of
(Standard_Natural, Loc),
Attribute_Name => Name_Min,
Expressions => New_List (
Make_Integer_Literal (Loc,
Scope_Depth (Body_Id)),
New_Occurrence_Of
(Extra_Access, Loc))));
-- Add the new local object to the Minimum_Acc_Obj to
-- be later prepended to the subprogram's list of
-- declarations after we are sure all expansion is
-- done.
if Present (Minimum_Acc_Objs) then
Prepend (Obj_Node, Minimum_Acc_Objs);
else
Minimum_Acc_Objs := New_List (Obj_Node);
end if;
-- Register the object and analyze it
Set_Minimum_Accessibility
(Form, Defining_Identifier (Obj_Node));
Analyze (Obj_Node);
end Generate_Minimum_Accessibility;
-------------------------------------
-- Is_Private_Concurrent_Primitive --
-------------------------------------
function Is_Private_Concurrent_Primitive
(Subp_Id : Entity_Id) return Boolean
is
Formal_Typ : Entity_Id;
begin
if Present (First_Formal (Subp_Id)) then
Formal_Typ := Etype (First_Formal (Subp_Id));
if Is_Concurrent_Record_Type (Formal_Typ) then
if Is_Class_Wide_Type (Formal_Typ) then
Formal_Typ := Root_Type (Formal_Typ);
end if;
Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ);
end if;
-- The type of the first formal is a concurrent tagged type with
-- a private view.
return
Is_Concurrent_Type (Formal_Typ)
and then Is_Tagged_Type (Formal_Typ)
and then Has_Private_Declaration (Formal_Typ);
end if;
return False;
end Is_Private_Concurrent_Primitive;
-------------------------
-- Mask_Unfrozen_Types --
-------------------------
function Mask_Unfrozen_Types (Spec_Id : Entity_Id) return Elist_Id is
Result : Elist_Id := No_Elist;
function Mask_Type_Refs (Node : Node_Id) return Traverse_Result;
-- Mask all types referenced in the subtree rooted at Node as
-- formally frozen.
--------------------
-- Mask_Type_Refs --
--------------------
function Mask_Type_Refs (Node : Node_Id) return Traverse_Result is
procedure Mask_Type (Typ : Entity_Id);
-- Mask a given type as formally frozen when outside the current
-- scope, or else freeze the type.
---------------
-- Mask_Type --
---------------
procedure Mask_Type (Typ : Entity_Id) is
begin
-- Skip Itypes created by the preanalysis
if Is_Itype (Typ)
and then Scope_Within_Or_Same (Scope (Typ), Spec_Id)
then
return;
end if;
if not Is_Frozen (Typ) then
if Scope (Typ) /= Current_Scope then
Set_Is_Frozen (Typ);
Append_New_Elmt (Typ, Result);
else
Freeze_Before (N, Typ);
end if;
end if;
end Mask_Type;
-- Start of processing for Mask_Type_Refs
begin
if Is_Entity_Name (Node) and then Present (Entity (Node)) then
Mask_Type (Etype (Entity (Node)));
if Ekind (Entity (Node)) in E_Component | E_Discriminant then
Mask_Type (Scope (Entity (Node)));
end if;
elsif Nkind (Node) in N_Aggregate | N_Null | N_Type_Conversion
and then Present (Etype (Node))
then
Mask_Type (Etype (Node));
end if;
return OK;
end Mask_Type_Refs;
procedure Mask_References is new Traverse_Proc (Mask_Type_Refs);
-- Local variables
Return_Stmt : constant Node_Id :=
First (Statements (Handled_Statement_Sequence (N)));
-- Start of processing for Mask_Unfrozen_Types
begin
pragma Assert (Nkind (Return_Stmt) = N_Simple_Return_Statement);
Mask_References (Expression (Return_Stmt));
return Result;
end Mask_Unfrozen_Types;
------------------
-- Move_Pragmas --
------------------
procedure Move_Pragmas (From : Node_Id; To : Node_Id) is
Decl : Node_Id;
Insert_Nod : Node_Id;
Next_Decl : Node_Id;
begin
pragma Assert (Nkind (From) = N_Subprogram_Body);
-- The pragmas are moved in an order-preserving fashion
Insert_Nod := To;
-- Inspect the declarations of the subprogram body and relocate all
-- candidate pragmas.
Decl := First (Declarations (From));
while Present (Decl) loop
-- Preserve the following declaration for iteration purposes, due
-- to possible relocation of a pragma.
Next_Decl := Next (Decl);
if Nkind (Decl) = N_Pragma then
-- Copy pragma SPARK_Mode if present in the declarative list
-- of subprogram body From and insert it after node To. This
-- pragma should not be moved, as it applies to the body too.
if Pragma_Name_Unmapped (Decl) = Name_SPARK_Mode then
Insert_After (Insert_Nod, New_Copy_Tree (Decl));
-- Move relevant pragmas to the spec
elsif Pragma_Name_Unmapped (Decl) in Name_Depends
| Name_Ghost
| Name_Global
| Name_Pre
| Name_Precondition
| Name_Post
| Name_Refined_Depends
| Name_Refined_Global
| Name_Refined_Post
| Name_Inline
| Name_Pure_Function
| Name_Volatile_Function
then
Remove (Decl);
Insert_After (Insert_Nod, Decl);
Insert_Nod := Decl;
end if;
-- Skip internally generated code
elsif not Comes_From_Source (Decl) then
null;
-- No candidate pragmas are available for relocation
else
exit;
end if;
Decl := Next_Decl;
end loop;
end Move_Pragmas;
---------------------------
-- Restore_Limited_Views --
---------------------------
procedure Restore_Limited_Views (Restore_List : Elist_Id) is
Elmt : Elmt_Id := First_Elmt (Restore_List);
Id : Entity_Id;
begin
while Present (Elmt) loop
Id := Node (Elmt);
Next_Elmt (Elmt);
Set_Etype (Id, Node (Elmt));
Next_Elmt (Elmt);
end loop;
end Restore_Limited_Views;
----------------------------
-- Set_Trivial_Subprogram --
----------------------------
procedure Set_Trivial_Subprogram (N : Node_Id) is
Nxt : constant Node_Id := Next (N);
begin
Set_Is_Trivial_Subprogram (Body_Id);
if Present (Spec_Id) then
Set_Is_Trivial_Subprogram (Spec_Id);
end if;
if Present (Nxt)
and then Nkind (Nxt) = N_Simple_Return_Statement
and then No (Next (Nxt))
and then Present (Expression (Nxt))
and then Is_Entity_Name (Expression (Nxt))
then
Set_Never_Set_In_Source (Entity (Expression (Nxt)), False);
end if;
end Set_Trivial_Subprogram;
---------------------------
-- Unmask_Unfrozen_Types --
---------------------------
procedure Unmask_Unfrozen_Types (Unmask_List : Elist_Id) is
Elmt : Elmt_Id := First_Elmt (Unmask_List);
begin
while Present (Elmt) loop
Set_Is_Frozen (Node (Elmt), False);
Next_Elmt (Elmt);
end loop;
end Unmask_Unfrozen_Types;
---------------------------------
-- Verify_Overriding_Indicator --
---------------------------------
procedure Verify_Overriding_Indicator is
begin
if Must_Override (Body_Spec) then
if Nkind (Spec_Id) = N_Defining_Operator_Symbol
and then Operator_Matches_Spec (Spec_Id, Spec_Id)
then
null;
-- Overridden controlled primitives may have had their
-- Overridden_Operation field cleared according to the setting of
-- the Is_Hidden flag. An issue arises, however, when analyzing
-- an instance that may have manipulated the flag during
-- expansion. As a result, we add an exception for this case.
elsif not Present (Overridden_Operation (Spec_Id))
and then not (Chars (Spec_Id) in Name_Adjust
| Name_Finalize
| Name_Initialize
and then In_Instance)
then
Error_Msg_NE
("subprogram& is not overriding", Body_Spec, Spec_Id);
-- Overriding indicators aren't allowed for protected subprogram
-- bodies (see the Confirmation in Ada Comment AC95-00213). Change
-- this to a warning if -gnatd.E is enabled.
elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then
Error_Msg_Warn := Error_To_Warning;
Error_Msg_N
("<<overriding indicator not allowed for protected "
& "subprogram body", Body_Spec);
end if;
elsif Must_Not_Override (Body_Spec) then
if Present (Overridden_Operation (Spec_Id)) then
Error_Msg_NE
("subprogram& overrides inherited operation",
Body_Spec, Spec_Id);
elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol
and then Operator_Matches_Spec (Spec_Id, Spec_Id)
then
Error_Msg_NE
("subprogram& overrides predefined operator",
Body_Spec, Spec_Id);
-- Overriding indicators aren't allowed for protected subprogram
-- bodies (see the Confirmation in Ada Comment AC95-00213). Change
-- this to a warning if -gnatd.E is enabled.
elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then
Error_Msg_Warn := Error_To_Warning;
Error_Msg_N
("<<overriding indicator not allowed "
& "for protected subprogram body", Body_Spec);
-- If this is not a primitive operation, then the overriding
-- indicator is altogether illegal.
elsif not Is_Primitive (Spec_Id) then
Error_Msg_N
("overriding indicator only allowed "
& "if subprogram is primitive", Body_Spec);
end if;
-- If checking the style rule and the operation overrides, then
-- issue a warning about a missing overriding_indicator. Protected
-- subprogram bodies are excluded from this style checking, since
-- they aren't primitives (even though their declarations can
-- override) and aren't allowed to have an overriding_indicator.
elsif Style_Check
and then Present (Overridden_Operation (Spec_Id))
and then Ekind (Scope (Spec_Id)) /= E_Protected_Type
then
pragma Assert (Unit_Declaration_Node (Body_Id) = N);
Style.Missing_Overriding (N, Body_Id);
elsif Style_Check
and then Can_Override_Operator (Spec_Id)
and then not In_Predefined_Unit (Spec_Id)
then
pragma Assert (Unit_Declaration_Node (Body_Id) = N);
Style.Missing_Overriding (N, Body_Id);
end if;
end Verify_Overriding_Indicator;
-- Local variables
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
Saved_EA : constant Boolean := Expander_Active;
Saved_ISMP : constant Boolean :=
Ignore_SPARK_Mode_Pragmas_In_Instance;
-- Save the Ghost and SPARK mode-related data to restore on exit
-- Start of processing for Analyze_Subprogram_Body_Helper
begin
-- A [generic] subprogram body freezes the contract of the nearest
-- enclosing package body and all other contracts encountered in the
-- same declarative part up to and excluding the subprogram body:
-- package body Nearest_Enclosing_Package
-- with Refined_State => (State => Constit)
-- is
-- Constit : ...;
-- procedure Freezes_Enclosing_Package_Body
-- with Refined_Depends => (Input => Constit) ...
-- This ensures that any annotations referenced by the contract of the
-- [generic] subprogram body are available. This form of freezing is
-- decoupled from the usual Freeze_xxx mechanism because it must also
-- work in the context of generics where normal freezing is disabled.
-- Only bodies coming from source should cause this type of freezing.
-- Expression functions that act as bodies and complete an initial
-- declaration must be included in this category, hence the use of
-- Original_Node.
if Comes_From_Source (Original_Node (N)) then
Freeze_Previous_Contracts (N);
end if;
-- Generic subprograms are handled separately. They always have a
-- generic specification. Determine whether current scope has a
-- previous declaration.
-- If the subprogram body is defined within an instance of the same
-- name, the instance appears as a package renaming, and will be hidden
-- within the subprogram.
if Present (Prev_Id)
and then not Is_Overloadable (Prev_Id)
and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
or else Comes_From_Source (Prev_Id))
then
if Is_Generic_Subprogram (Prev_Id) then
Spec_Id := Prev_Id;
-- A subprogram body is Ghost when it is stand-alone and subject
-- to pragma Ghost or when the corresponding spec is Ghost. Set
-- the mode now to ensure that any nodes generated during analysis
-- and expansion are properly marked as Ghost.
Mark_And_Set_Ghost_Body (N, Spec_Id);
-- If the body completes the initial declaration of a compilation
-- unit which is subject to pragma Elaboration_Checks, set the
-- model specified by the pragma because it applies to all parts
-- of the unit.
Install_Elaboration_Model (Spec_Id);
Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
Analyze_Generic_Subprogram_Body (N, Spec_Id);
if Nkind (N) = N_Subprogram_Body then
HSS := Handled_Statement_Sequence (N);
Check_Missing_Return;
end if;
goto Leave;
-- Otherwise a previous entity conflicts with the subprogram name.
-- Attempting to enter name will post error.
else
Enter_Name (Body_Id);
goto Leave;
end if;
-- Non-generic case, find the subprogram declaration, if one was seen,
-- or enter new overloaded entity in the current scope. If the
-- Current_Entity is the Body_Id itself, the unit is being analyzed as
-- part of the context of one of its subunits. No need to redo the
-- analysis.
elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then
goto Leave;
else
Body_Id := Analyze_Subprogram_Specification (Body_Spec);
if Nkind (N) = N_Subprogram_Body_Stub
or else No (Corresponding_Spec (N))
then
if Is_Private_Concurrent_Primitive (Body_Id) then
Spec_Id := Disambiguate_Spec;
-- A subprogram body is Ghost when it is stand-alone and
-- subject to pragma Ghost or when the corresponding spec is
-- Ghost. Set the mode now to ensure that any nodes generated
-- during analysis and expansion are properly marked as Ghost.
Mark_And_Set_Ghost_Body (N, Spec_Id);
-- If the body completes a compilation unit which is subject
-- to pragma Elaboration_Checks, set the model specified by
-- the pragma because it applies to all parts of the unit.
Install_Elaboration_Model (Spec_Id);
else
Spec_Id := Find_Corresponding_Spec (N);
-- A subprogram body is Ghost when it is stand-alone and
-- subject to pragma Ghost or when the corresponding spec is
-- Ghost. Set the mode now to ensure that any nodes generated
-- during analysis and expansion are properly marked as Ghost.
Mark_And_Set_Ghost_Body (N, Spec_Id);
-- If the body completes a compilation unit which is subject
-- to pragma Elaboration_Checks, set the model specified by
-- the pragma because it applies to all parts of the unit.
Install_Elaboration_Model (Spec_Id);
-- In GNATprove mode, if the body has no previous spec, create
-- one so that the inlining machinery can operate properly.
-- Transfer aspects, if any, to the new spec, so that they
-- are legal and can be processed ahead of the body.
-- We make two copies of the given spec, one for the new
-- declaration, and one for the body.
-- ??? This should be conditioned on front-end inlining rather
-- than GNATprove_Mode.
if No (Spec_Id) and then GNATprove_Mode
-- Inlining does not apply during preanalysis of code
and then Full_Analysis
-- Inlining only applies to full bodies, not stubs
and then Nkind (N) /= N_Subprogram_Body_Stub
-- Inlining only applies to bodies in the source code, not to
-- those generated by the compiler. In particular, expression
-- functions, whose body is generated by the compiler, are
-- treated specially by GNATprove.
and then Comes_From_Source (Body_Id)
-- This cannot be done for a compilation unit, which is not
-- in a context where we can insert a new spec.
and then Is_List_Member (N)
-- Inlining only applies to subprograms without contracts,
-- as a contract is a sign that GNATprove should perform a
-- modular analysis of the subprogram instead of a contextual
-- analysis at each call site. The same test is performed in
-- Inline.Can_Be_Inlined_In_GNATprove_Mode. It is repeated
-- here in another form (because the contract has not been
-- attached to the body) to avoid front-end errors in case
-- pragmas are used instead of aspects, because the
-- corresponding pragmas in the body would not be transferred
-- to the spec, leading to legality errors.
and then not Body_Has_Contract
and then not Inside_A_Generic
then
Build_Subprogram_Declaration;
-- If this is a function that returns a constrained array, and
-- Transform_Function_Array is set, create subprogram
-- declaration to simplify e.g. subsequent C generation.
elsif No (Spec_Id)
and then Transform_Function_Array
and then Nkind (Body_Spec) = N_Function_Specification
and then Is_Array_Type (Etype (Body_Id))
and then Is_Constrained (Etype (Body_Id))
then
Build_Subprogram_Declaration;
end if;
end if;
-- If this is a duplicate body, no point in analyzing it
if Error_Posted (N) then
goto Leave;
end if;
-- A subprogram body should cause freezing of its own declaration,
-- but if there was no previous explicit declaration, then the
-- subprogram will get frozen too late (there may be code within
-- the body that depends on the subprogram having been frozen,
-- such as uses of extra formals), so we force it to be frozen
-- here. Same holds if the body and spec are compilation units.
-- Finally, if the return type is an anonymous access to protected
-- subprogram, it must be frozen before the body because its
-- expansion has generated an equivalent type that is used when
-- elaborating the body.
-- An exception in the case of Ada 2012, AI05-177: The bodies
-- created for expression functions do not freeze.
if No (Spec_Id)
and then Nkind (Original_Node (N)) /= N_Expression_Function
then
Freeze_Before (N, Body_Id);
elsif Nkind (Parent (N)) = N_Compilation_Unit then
Freeze_Before (N, Spec_Id);
elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then
Freeze_Before (N, Etype (Body_Id));
end if;
else
Spec_Id := Corresponding_Spec (N);
-- A subprogram body is Ghost when it is stand-alone and subject
-- to pragma Ghost or when the corresponding spec is Ghost. Set
-- the mode now to ensure that any nodes generated during analysis
-- and expansion are properly marked as Ghost.
Mark_And_Set_Ghost_Body (N, Spec_Id);
-- If the body completes the initial declaration of a compilation
-- unit which is subject to pragma Elaboration_Checks, set the
-- model specified by the pragma because it applies to all parts
-- of the unit.
Install_Elaboration_Model (Spec_Id);
end if;
end if;
-- Deactivate expansion inside the body of ignored Ghost entities,
-- as this code will ultimately be ignored. This avoids requiring the
-- presence of run-time units which are not needed. Only do this for
-- user entities, as internally generated entitities might still need
-- to be expanded (e.g. those generated for types).
if Present (Ignored_Ghost_Region)
and then Comes_From_Source (Body_Id)
then
Expander_Active := False;
end if;
-- Previously we scanned the body to look for nested subprograms, and
-- rejected an inline directive if nested subprograms were present,
-- because the back-end would generate conflicting symbols for the
-- nested bodies. This is now unnecessary.
-- Look ahead to recognize a pragma Inline that appears after the body
Check_Inline_Pragma (Spec_Id);
-- Deal with special case of a fully private operation in the body of
-- the protected type. We must create a declaration for the subprogram,
-- in order to attach the subprogram that will be used in internal
-- calls. We exclude compiler generated bodies from the expander since
-- the issue does not arise for those cases.
if No (Spec_Id)
and then Comes_From_Source (N)
and then Is_Protected_Type (Current_Scope)
then
Spec_Id := Build_Internal_Protected_Declaration (N);
end if;
-- If Transform_Function_Array is set and this is a function returning a
-- constrained array type for which we must create a procedure with an
-- extra out parameter, build and analyze the body now. The procedure
-- declaration has already been created. We reuse the source body of the
-- function, because in an instance it may contain global references
-- that cannot be reanalyzed. The source function itself is not used any
-- further, so we mark it as having a completion. If the subprogram is a
-- stub the transformation is done later, when the proper body is
-- analyzed.
if Expander_Active
and then Transform_Function_Array
and then Nkind (N) /= N_Subprogram_Body_Stub
then
declare
S : constant Entity_Id :=
(if Present (Spec_Id)
then Spec_Id
else Defining_Unit_Name (Specification (N)));
Proc_Body : Node_Id;
begin
if Ekind (S) = E_Function and then Rewritten_For_C (S) then
Set_Has_Completion (S);
Proc_Body := Build_Procedure_Body_Form (S, N);
if Present (Spec_Id) then
Rewrite (N, Proc_Body);
Analyze (N);
-- The entity for the created procedure must remain
-- invisible, so it does not participate in resolution of
-- subsequent references to the function.
Set_Is_Immediately_Visible (Corresponding_Spec (N), False);
-- If we do not have a separate spec for N, build one and
-- insert the new body right after.
else
Rewrite (N,
Make_Subprogram_Declaration (Loc,
Specification => Relocate_Node (Specification (N))));
Analyze (N);
Insert_After_And_Analyze (N, Proc_Body);
Set_Is_Immediately_Visible
(Corresponding_Spec (Proc_Body), False);
end if;
goto Leave;
end if;
end;
end if;
-- If a separate spec is present, then deal with freezing issues
if Present (Spec_Id) then
Spec_Decl := Unit_Declaration_Node (Spec_Id);
Verify_Overriding_Indicator;
-- In general, the spec will be frozen when we start analyzing the
-- body. However, for internally generated operations, such as
-- wrapper functions for inherited operations with controlling
-- results, the spec may not have been frozen by the time we expand
-- the freeze actions that include the bodies. In particular, extra
-- formals for accessibility or for return-in-place may need to be
-- generated. Freeze nodes, if any, are inserted before the current
-- body. These freeze actions are also needed in Compile_Only mode to
-- enable the proper back-end type annotations.
-- They are necessary in any case to ensure proper elaboration order
-- in gigi.
if Nkind (N) = N_Subprogram_Body
and then Was_Expression_Function (N)
and then not Has_Completion (Spec_Id)
and then Serious_Errors_Detected = 0
and then (Expander_Active
or else Operating_Mode = Check_Semantics
or else Is_Ignored_Ghost_Entity (Spec_Id))
then
-- The body generated for an expression function that is not a
-- completion is a freeze point neither for the profile nor for
-- anything else. That's why, in order to prevent any freezing
-- during analysis, we need to mask types declared outside the
-- expression (and in an outer scope) that are not yet frozen.
-- This also needs to be done in the case of an ignored Ghost
-- expression function, where the expander isn't active.
Set_Is_Frozen (Spec_Id);
Mask_Types := Mask_Unfrozen_Types (Spec_Id);
elsif not Is_Frozen (Spec_Id)
and then Serious_Errors_Detected = 0
then
Set_Has_Delayed_Freeze (Spec_Id);
Freeze_Before (N, Spec_Id);
end if;
end if;
-- Place subprogram on scope stack, and make formals visible. If there
-- is a spec, the visible entity remains that of the spec.
if Present (Spec_Id) then
Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
if Is_Child_Unit (Spec_Id) then
Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False);
end if;
if Style_Check then
Style.Check_Identifier (Body_Id, Spec_Id);
end if;
Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
if Is_Abstract_Subprogram (Spec_Id) then
Error_Msg_N ("an abstract subprogram cannot have a body", N);
goto Leave;
else
Set_Convention (Body_Id, Convention (Spec_Id));
Set_Has_Completion (Spec_Id);
if Is_Protected_Type (Scope (Spec_Id)) then
Prot_Typ := Scope (Spec_Id);
end if;
-- If this is a body generated for a renaming, do not check for
-- full conformance. The check is redundant, because the spec of
-- the body is a copy of the spec in the renaming declaration,
-- and the test can lead to spurious errors on nested defaults.
if Present (Spec_Decl)
and then not Comes_From_Source (N)
and then
(Nkind (Original_Node (Spec_Decl)) =
N_Subprogram_Renaming_Declaration
or else (Present (Corresponding_Body (Spec_Decl))
and then
Nkind (Unit_Declaration_Node
(Corresponding_Body (Spec_Decl))) =
N_Subprogram_Renaming_Declaration))
then
Conformant := True;
-- Conversely, the spec may have been generated for specless body
-- with an inline pragma. The entity comes from source, which is
-- both semantically correct and necessary for proper inlining.
-- The subprogram declaration itself is not in the source.
elsif Comes_From_Source (N)
and then Present (Spec_Decl)
and then not Comes_From_Source (Spec_Decl)
and then Has_Pragma_Inline (Spec_Id)
then
Conformant := True;
-- Finally, a body generated for an expression function copies
-- the profile of the function and no check is needed either.
-- If the body is the completion of a previous function
-- declared elsewhere, the conformance check is required.
elsif Nkind (N) = N_Subprogram_Body
and then Was_Expression_Function (N)
and then Sloc (Spec_Id) = Sloc (Body_Id)
then
Conformant := True;
else
Check_Conformance
(Body_Id, Spec_Id,
Fully_Conformant, True, Conformant, Body_Id);
end if;
-- If the body is not fully conformant, we have to decide if we
-- should analyze it or not. If it has a really messed up profile
-- then we probably should not analyze it, since we will get too
-- many bogus messages.
-- Our decision is to go ahead in the non-fully conformant case
-- only if it is at least mode conformant with the spec. Note
-- that the call to Check_Fully_Conformant has issued the proper
-- error messages to complain about the lack of conformance.
if not Conformant
and then not Mode_Conformant (Body_Id, Spec_Id)
then
goto Leave;
end if;
end if;
-- In the case we are dealing with an expression function we check
-- the formals attached to the spec instead of the body - so we don't
-- reference body formals.
if Spec_Id /= Body_Id
and then not Is_Expression_Function (Spec_Id)
then
Reference_Body_Formals (Spec_Id, Body_Id);
end if;
Reinit_Field_To_Zero (Body_Id, F_Has_Out_Or_In_Out_Parameter);
Reinit_Field_To_Zero (Body_Id, F_Needs_No_Actuals,
Old_Ekind => (E_Function | E_Procedure => True, others => False));
Reinit_Field_To_Zero (Body_Id, F_Is_Predicate_Function,
Old_Ekind => (E_Function | E_Procedure => True, others => False));
Reinit_Field_To_Zero (Body_Id, F_Protected_Subprogram,
Old_Ekind => (E_Function | E_Procedure => True, others => False));
if Ekind (Body_Id) = E_Procedure then
Reinit_Field_To_Zero (Body_Id, F_Receiving_Entry);
end if;
Mutate_Ekind (Body_Id, E_Subprogram_Body);
if Nkind (N) = N_Subprogram_Body_Stub then
Set_Corresponding_Spec_Of_Stub (N, Spec_Id);
-- Regular body
else
Set_Corresponding_Spec (N, Spec_Id);
-- Ada 2005 (AI-345): If the operation is a primitive operation
-- of a concurrent type, the type of the first parameter has been
-- replaced with the corresponding record, which is the proper
-- run-time structure to use. However, within the body there may
-- be uses of the formals that depend on primitive operations
-- of the type (in particular calls in prefixed form) for which
-- we need the original concurrent type. The operation may have
-- several controlling formals, so the replacement must be done
-- for all of them.
if Comes_From_Source (Spec_Id)
and then Present (First_Entity (Spec_Id))
and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type
and then Is_Tagged_Type (Etype (First_Entity (Spec_Id)))
and then Present (Interfaces (Etype (First_Entity (Spec_Id))))
and then Present (Corresponding_Concurrent_Type
(Etype (First_Entity (Spec_Id))))
then
declare
Typ : constant Entity_Id := Etype (First_Entity (Spec_Id));
Form : Entity_Id;
begin
Form := First_Formal (Spec_Id);
while Present (Form) loop
if Etype (Form) = Typ then
Set_Etype (Form, Corresponding_Concurrent_Type (Typ));
end if;
Next_Formal (Form);
end loop;
end;
end if;
-- Make the formals visible, and place subprogram on scope stack.
-- This is also the point at which we set Last_Real_Spec_Entity
-- to mark the entities which will not be moved to the body.
Install_Formals (Spec_Id);
Last_Real_Spec_Entity := Last_Entity (Spec_Id);
-- Within an instance, add local renaming declarations so that
-- gdb can retrieve the values of actuals more easily. This is
-- only relevant if generating code.
if Is_Generic_Instance (Spec_Id)
and then Is_Wrapper_Package (Current_Scope)
and then Expander_Active
then
Build_Subprogram_Instance_Renamings (N, Current_Scope);
end if;
Push_Scope (Spec_Id);
-- Make sure that the subprogram is immediately visible. For
-- child units that have no separate spec this is indispensable.
-- Otherwise it is safe albeit redundant.
Set_Is_Immediately_Visible (Spec_Id);
end if;
Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
Set_Scope (Body_Id, Scope (Spec_Id));
-- Case of subprogram body with no previous spec
else
-- Check for style warning required
if Style_Check
-- Only apply check for source level subprograms for which checks
-- have not been suppressed.
and then Comes_From_Source (Body_Id)
and then not Suppress_Style_Checks (Body_Id)
-- No warnings within an instance
and then not In_Instance
-- No warnings for expression functions
and then Nkind (Original_Node (N)) /= N_Expression_Function
then
Style.Body_With_No_Spec (N);
end if;
New_Overloaded_Entity (Body_Id);
if Nkind (N) /= N_Subprogram_Body_Stub then
Set_Acts_As_Spec (N);
Generate_Definition (Body_Id);
Generate_Reference
(Body_Id, Body_Id, 'b', Set_Ref => False, Force => True);
-- If the body is an entry wrapper created for an entry with
-- preconditions, it must be compiled in the context of the
-- enclosing synchronized object, because it may mention other
-- operations of the type.
if Is_Entry_Wrapper (Body_Id) then
declare
Prot : constant Entity_Id := Etype (First_Entity (Body_Id));
begin
Push_Scope (Prot);
Install_Declarations (Prot);
end;
end if;
Install_Formals (Body_Id);
Push_Scope (Body_Id);
end if;
-- For stubs and bodies with no previous spec, generate references to
-- formals.
Generate_Reference_To_Formals (Body_Id);
end if;
-- Entry barrier functions are generated outside the protected type and
-- should not carry the SPARK_Mode of the enclosing context.
if Nkind (N) = N_Subprogram_Body
and then Is_Entry_Barrier_Function (N)
then
null;
-- The body is generated as part of expression function expansion. When
-- the expression function appears in the visible declarations of a
-- package, the body is added to the private declarations. Since both
-- declarative lists may be subject to a different SPARK_Mode, inherit
-- the mode of the spec.
-- package P with SPARK_Mode is
-- function Expr_Func ... is (...); -- original
-- [function Expr_Func ...;] -- generated spec
-- -- mode is ON
-- private
-- pragma SPARK_Mode (Off);
-- [function Expr_Func ... is return ...;] -- generated body
-- end P; -- mode is ON
elsif not Comes_From_Source (N)
and then Present (Spec_Id)
and then Is_Expression_Function (Spec_Id)
then
Set_SPARK_Pragma (Body_Id, SPARK_Pragma (Spec_Id));
Set_SPARK_Pragma_Inherited
(Body_Id, SPARK_Pragma_Inherited (Spec_Id));
-- Set the SPARK_Mode from the current context (may be overwritten later
-- with explicit pragma). Exclude the case where the SPARK_Mode appears
-- initially on a stand-alone subprogram body, but is then relocated to
-- a generated corresponding spec. In this scenario the mode is shared
-- between the spec and body.
elsif No (SPARK_Pragma (Body_Id)) then
Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Body_Id);
end if;
-- A subprogram body may be instantiated or inlined at a later pass.
-- Restore the state of Ignore_SPARK_Mode_Pragmas_In_Instance when it
-- applied to the initial declaration of the body.
if Present (Spec_Id) then
if Ignore_SPARK_Mode_Pragmas (Spec_Id) then
Ignore_SPARK_Mode_Pragmas_In_Instance := True;
end if;
else
-- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in
-- case the body is instantiated or inlined later and out of context.
-- The body uses this attribute to restore the value of the global
-- flag.
if Ignore_SPARK_Mode_Pragmas_In_Instance then
Set_Ignore_SPARK_Mode_Pragmas (Body_Id);
elsif Ignore_SPARK_Mode_Pragmas (Body_Id) then
Ignore_SPARK_Mode_Pragmas_In_Instance := True;
end if;
end if;
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
if No (Spec_Id) then
Mark_Elaboration_Attributes
(N_Id => Body_Id,
Checks => True,
Warnings => True);
end if;
-- If this is the proper body of a stub, we must verify that the stub
-- conforms to the body, and to the previous spec if one was present.
-- We know already that the body conforms to that spec. This test is
-- only required for subprograms that come from source.
if Nkind (Parent (N)) = N_Subunit
and then Comes_From_Source (N)
and then not Error_Posted (Body_Id)
and then Nkind (Corresponding_Stub (Parent (N))) =
N_Subprogram_Body_Stub
then
declare
Old_Id : constant Entity_Id :=
Defining_Entity
(Specification (Corresponding_Stub (Parent (N))));
Conformant : Boolean := False;
begin
if No (Spec_Id) then
Check_Fully_Conformant (Body_Id, Old_Id);
else
Check_Conformance
(Body_Id, Old_Id, Fully_Conformant, False, Conformant);
if not Conformant then
-- The stub was taken to be a new declaration. Indicate that
-- it lacks a body.
Set_Has_Completion (Old_Id, False);
end if;
end if;
end;
end if;
Set_Has_Completion (Body_Id);
Check_Eliminated (Body_Id);
-- Analyze any aspect specifications that appear on the subprogram body
-- stub. Stop the analysis now as the stub does not have a declarative
-- or a statement part, and it cannot be inlined.
if Nkind (N) = N_Subprogram_Body_Stub then
if Has_Aspects (N) then
Analyze_Aspects_On_Subprogram_Body_Or_Stub (N);
end if;
goto Leave;
end if;
-- Handle inlining
if Expander_Active
and then Serious_Errors_Detected = 0
and then Present (Spec_Id)
and then Has_Pragma_Inline (Spec_Id)
then
-- Legacy implementation (relying on front-end inlining)
if not Back_End_Inlining then
if Has_Pragma_Inline_Always (Spec_Id)
or else (Front_End_Inlining
and then not Opt.Disable_FE_Inline)
then
Build_Body_To_Inline (N, Spec_Id);
end if;
-- New implementation (relying on back-end inlining)
else
if Has_Pragma_Inline_Always (Spec_Id)
or else Optimization_Level > 0
then
-- Handle function returning an unconstrained type
if Comes_From_Source (Body_Id)
and then Ekind (Spec_Id) = E_Function
and then Returns_Unconstrained_Type (Spec_Id)
-- If function builds in place, i.e. returns a limited type,
-- inlining cannot be done.
and then not Is_Limited_Type (Etype (Spec_Id))
then
Check_And_Split_Unconstrained_Function (N, Spec_Id, Body_Id);
else
declare
Subp_Body : constant Node_Id :=
Unit_Declaration_Node (Body_Id);
Subp_Decl : constant List_Id := Declarations (Subp_Body);
begin
-- Do not pass inlining to the backend if the subprogram
-- has declarations or statements which cannot be inlined
-- by the backend. This check is done here to emit an
-- error instead of the generic warning message reported
-- by the GCC backend (ie. "function might not be
-- inlinable").
if Present (Subp_Decl)
and then Has_Excluded_Declaration (Spec_Id, Subp_Decl)
then
null;
elsif Has_Excluded_Statement
(Spec_Id,
Statements
(Handled_Statement_Sequence (Subp_Body)))
then
null;
-- If the backend inlining is available then at this
-- stage we only have to mark the subprogram as inlined.
-- The expander will take care of registering it in the
-- table of subprograms inlined by the backend a part of
-- processing calls to it (cf. Expand_Call)
else
Set_Is_Inlined (Spec_Id);
end if;
end;
end if;
end if;
end if;
-- In GNATprove mode, inline only when there is a separate subprogram
-- declaration for now, as inlining of subprogram bodies acting as
-- declarations, or subprogram stubs, are not supported by front-end
-- inlining. This inlining should occur after analysis of the body, so
-- that it is known whether the value of SPARK_Mode, which can be
-- defined by a pragma inside the body, is applicable to the body.
-- Inlining can be disabled with switch -gnatdm
elsif GNATprove_Mode
and then Full_Analysis
and then not Inside_A_Generic
and then Present (Spec_Id)
and then
Nkind (Unit_Declaration_Node (Spec_Id)) = N_Subprogram_Declaration
and then Body_Has_SPARK_Mode_On
and then Can_Be_Inlined_In_GNATprove_Mode (Spec_Id, Body_Id)
and then not Body_Has_Contract
and then not Debug_Flag_M
then
Build_Body_To_Inline (N, Spec_Id);
end if;
-- When generating code, inherited pre/postconditions are handled when
-- expanding the corresponding contract.
-- Ada 2005 (AI-262): In library subprogram bodies, after the analysis
-- of the specification we have to install the private withed units.
-- This holds for child units as well.
if Is_Compilation_Unit (Body_Id)
or else Nkind (Parent (N)) = N_Compilation_Unit
then
Install_Private_With_Clauses (Body_Id);
end if;
Check_Anonymous_Return;
-- Set the Protected_Formal field of each extra formal of the protected
-- subprogram to reference the corresponding extra formal of the
-- subprogram that implements it. For regular formals this occurs when
-- the protected subprogram's declaration is expanded, but the extra
-- formals don't get created until the subprogram is frozen. We need to
-- do this before analyzing the protected subprogram's body so that any
-- references to the original subprogram's extra formals will be changed
-- refer to the implementing subprogram's formals (see Expand_Formal).
if Present (Spec_Id)
and then Is_Protected_Type (Scope (Spec_Id))
and then Present (Protected_Body_Subprogram (Spec_Id))
then
declare
Impl_Subp : constant Entity_Id :=
Protected_Body_Subprogram (Spec_Id);
Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id);
Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp);
begin
while Present (Prot_Ext_Formal) loop
pragma Assert (Present (Impl_Ext_Formal));
Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal);
Next_Formal_With_Extras (Prot_Ext_Formal);
Next_Formal_With_Extras (Impl_Ext_Formal);
end loop;
end;
end if;
-- Generate minimum accessibility local objects to correspond with
-- any extra formal added for anonymous access types. This new local
-- object can then be used instead of the formal in case it is used
-- in an actual to a call to a nested subprogram.
-- This method is used to supplement our "small integer model" for
-- accessibility-check generation (for more information see
-- Accessibility_Level).
-- Because we allow accessibility values greater than our expected value
-- passing along the same extra accessibility formal as an actual
-- to a nested subprogram becomes a problem because high values mean
-- different things to the callee even though they are the same to the
-- caller. So, as described in the first section, we create a local
-- object representing the minimum of the accessibility level value that
-- is passed in and the accessibility level of the callee's parameter
-- and locals and use it in the case of a call to a nested subprogram.
-- This generated object is refered to as a "minimum accessiblity
-- level."
if Present (Spec_Id) or else Present (Body_Id) then
Body_Nod := Unit_Declaration_Node (Body_Id);
declare
Form : Entity_Id;
begin
-- Grab the appropriate formal depending on whether there exists
-- an actual spec for the subprogram or whether we are dealing
-- with a protected subprogram.
if Present (Spec_Id) then
if Present (Protected_Body_Subprogram (Spec_Id)) then
Form := First_Formal (Protected_Body_Subprogram (Spec_Id));
else
Form := First_Formal (Spec_Id);
end if;
else
Form := First_Formal (Body_Id);
end if;
-- Loop through formals if the subprogram is capable of accepting
-- a generated local object. If it is not then it is also not
-- capable of having local subprograms meaning it would not need
-- a minimum accessibility level object anyway.
if Present (Body_Nod)
and then Has_Declarations (Body_Nod)
and then Nkind (Body_Nod) /= N_Package_Specification
then
while Present (Form) loop
if Present (Extra_Accessibility (Form))
and then No (Minimum_Accessibility (Form))
then
-- Generate the minimum accessibility level object
-- A60b : constant natural := natural'min(1, paramL);
Generate_Minimum_Accessibility
(Extra_Accessibility (Form), Form);
end if;
Next_Formal (Form);
end loop;
-- Generate the minimum accessibility level object for the
-- function's Extra_Accessibility_Of_Result.
-- A31b : constant natural := natural'min (2, funcL);
if Ekind (Body_Id) = E_Function
and then Present (Extra_Accessibility_Of_Result (Body_Id))
then
Generate_Minimum_Accessibility
(Extra_Accessibility_Of_Result (Body_Id));
-- Replace the Extra_Accessibility_Of_Result with the new
-- minimum accessibility object.
Set_Extra_Accessibility_Of_Result
(Body_Id, Minimum_Accessibility
(Extra_Accessibility_Of_Result (Body_Id)));
end if;
end if;
end;
end if;
-- Now we can go on to analyze the body
HSS := Handled_Statement_Sequence (N);
Set_Actual_Subtypes (N, Current_Scope);
-- Add a declaration for the Protection object, renaming declarations
-- for discriminals and privals and finally a declaration for the entry
-- family index (if applicable). This form of early expansion is done
-- when the Expander is active because Install_Private_Data_Declarations
-- references entities which were created during regular expansion. The
-- subprogram entity must come from source, and not be an internally
-- generated subprogram.
if Expander_Active
and then Present (Prot_Typ)
and then Present (Spec_Id)
and then Comes_From_Source (Spec_Id)
and then not Is_Eliminated (Spec_Id)
then
Install_Private_Data_Declarations
(Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N));
end if;
-- Ada 2012 (AI05-0151): Incomplete types coming from a limited context
-- may now appear in parameter and result profiles. Since the analysis
-- of a subprogram body may use the parameter and result profile of the
-- spec, swap any limited views with their non-limited counterpart.
if Ada_Version >= Ada_2012 and then Present (Spec_Id) then
Exch_Views := Exchange_Limited_Views (Spec_Id);
end if;
-- If the return type is an anonymous access type whose designated type
-- is the limited view of a class-wide type and the non-limited view is
-- available, update the return type accordingly.
if Ada_Version >= Ada_2005 and then Present (Spec_Id) then
declare
Etyp : Entity_Id;
Rtyp : Entity_Id;
begin
Rtyp := Etype (Spec_Id);
if Ekind (Rtyp) = E_Anonymous_Access_Type then
Etyp := Directly_Designated_Type (Rtyp);
if Is_Class_Wide_Type (Etyp)
and then From_Limited_With (Etyp)
then
Desig_View := Etyp;
Set_Directly_Designated_Type (Rtyp, Available_View (Etyp));
end if;
end if;
end;
end if;
-- Analyze any aspect specifications that appear on the subprogram body
if Has_Aspects (N) then
Analyze_Aspects_On_Subprogram_Body_Or_Stub (N);
end if;
Analyze_Declarations (Declarations (N));
-- Verify that the SPARK_Mode of the body agrees with that of its spec
if Present (Spec_Id) and then Present (SPARK_Pragma (Body_Id)) then
if Present (SPARK_Pragma (Spec_Id)) then
if Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Spec_Id)) = Off
and then
Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = On
then
Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id));
Error_Msg_N ("incorrect application of SPARK_Mode#", N);
Error_Msg_Sloc := Sloc (SPARK_Pragma (Spec_Id));
Error_Msg_NE
("\value Off was set for SPARK_Mode on & #", N, Spec_Id);
end if;
elsif Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Body_Stub then
null;
-- SPARK_Mode Off could complete no SPARK_Mode in a generic, either
-- as specified in source code, or because SPARK_Mode On is ignored
-- in an instance where the context is SPARK_Mode Off/Auto.
elsif Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = Off
and then (Is_Generic_Unit (Spec_Id) or else In_Instance)
then
null;
else
Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id));
Error_Msg_N ("incorrect application of SPARK_Mode #", N);
Error_Msg_Sloc := Sloc (Spec_Id);
Error_Msg_NE
("\no value was set for SPARK_Mode on & #", N, Spec_Id);
end if;
end if;
-- A subprogram body freezes its own contract. Analyze the contract
-- after the declarations of the body have been processed as pragmas
-- are now chained on the contract of the subprogram body.
Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id);
-- Check completion, and analyze the statements
Check_Completion;
Inspect_Deferred_Constant_Completion (Declarations (N));
Analyze (HSS);
-- Add the generated minimum accessibility objects to the subprogram
-- body's list of declarations after analysis of the statements and
-- contracts.
while Is_Non_Empty_List (Minimum_Acc_Objs) loop
if Present (Declarations (Body_Nod)) then
Prepend (Remove_Head (Minimum_Acc_Objs), Declarations (Body_Nod));
else
Set_Declarations
(Body_Nod, New_List (Remove_Head (Minimum_Acc_Objs)));
end if;
end loop;
-- Deal with end of scope processing for the body
Process_End_Label (HSS, 't', Current_Scope);
Update_Use_Clause_Chain;
End_Scope;
-- If we are compiling an entry wrapper, remove the enclosing
-- synchronized object from the stack.
if Is_Entry_Wrapper (Body_Id) then
End_Scope;
end if;
Check_Subprogram_Order (N);
Set_Analyzed (Body_Id);
-- If we have a separate spec, then the analysis of the declarations
-- caused the entities in the body to be chained to the spec id, but
-- we want them chained to the body id. Only the formal parameters
-- end up chained to the spec id in this case.
if Present (Spec_Id) then
-- We must conform to the categorization of our spec
Validate_Categorization_Dependency (N, Spec_Id);
-- And if this is a child unit, the parent units must conform
if Is_Child_Unit (Spec_Id) then
Validate_Categorization_Dependency
(Unit_Declaration_Node (Spec_Id), Spec_Id);
end if;
-- Here is where we move entities from the spec to the body
-- Case where there are entities that stay with the spec
if Present (Last_Real_Spec_Entity) then
-- No body entities (happens when the only real spec entities come
-- from precondition and postcondition pragmas).
if No (Last_Entity (Body_Id)) then
Set_First_Entity (Body_Id, Next_Entity (Last_Real_Spec_Entity));
-- Body entities present (formals), so chain stuff past them
else
Link_Entities
(Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity));
end if;
Set_Next_Entity (Last_Real_Spec_Entity, Empty);
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity);
-- Case where there are no spec entities, in this case there can be
-- no body entities either, so just move everything.
-- If the body is generated for an expression function, it may have
-- been preanalyzed already, if 'access was applied to it.
else
if Nkind (Original_Node (Unit_Declaration_Node (Spec_Id))) /=
N_Expression_Function
then
pragma Assert (No (Last_Entity (Body_Id)));
null;
end if;
Set_First_Entity (Body_Id, First_Entity (Spec_Id));
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_First_Entity (Spec_Id, Empty);
Set_Last_Entity (Spec_Id, Empty);
end if;
-- Otherwise the body does not complete a previous declaration. Check
-- the categorization of the body against the units it withs.
else
Validate_Categorization_Dependency (N, Body_Id);
end if;
Check_Missing_Return;
-- Now we are going to check for variables that are never modified in
-- the body of the procedure. But first we deal with a special case
-- where we want to modify this check. If the body of the subprogram
-- starts with a raise statement or its equivalent, or if the body
-- consists entirely of a null statement, then it is pretty obvious that
-- it is OK to not reference the parameters. For example, this might be
-- the following common idiom for a stubbed function: statement of the
-- procedure raises an exception. In particular this deals with the
-- common idiom of a stubbed function, which appears something like:
-- function F (A : Integer) return Some_Type;
-- X : Some_Type;
-- begin
-- raise Program_Error;
-- return X;
-- end F;
-- Here the purpose of X is simply to satisfy the annoying requirement
-- in Ada that there be at least one return, and we certainly do not
-- want to go posting warnings on X that it is not initialized. On
-- the other hand, if X is entirely unreferenced that should still
-- get a warning.
-- What we do is to detect these cases, and if we find them, flag the
-- subprogram as being Is_Trivial_Subprogram and then use that flag to
-- suppress unwanted warnings. For the case of the function stub above
-- we have a special test to set X as apparently assigned to suppress
-- the warning.
declare
Stm : Node_Id;
begin
-- Skip call markers installed by the ABE mechanism, labels, and
-- Push_xxx_Error_Label to find the first real statement.
Stm := First (Statements (HSS));
while Nkind (Stm) in N_Call_Marker | N_Label | N_Push_xxx_Label loop
Next (Stm);
end loop;
-- Do the test on the original statement before expansion
declare
Ostm : constant Node_Id := Original_Node (Stm);
begin
-- If explicit raise statement, turn on flag
if Nkind (Ostm) = N_Raise_Statement then
Set_Trivial_Subprogram (Stm);
-- If null statement, and no following statements, turn on flag
elsif Nkind (Stm) = N_Null_Statement
and then Comes_From_Source (Stm)
and then No (Next (Stm))
then
Set_Trivial_Subprogram (Stm);
-- Check for explicit call cases which likely raise an exception
elsif Nkind (Ostm) = N_Procedure_Call_Statement then
if Is_Entity_Name (Name (Ostm)) then
declare
Ent : constant Entity_Id := Entity (Name (Ostm));
begin
-- If the procedure is marked No_Return, then likely it
-- raises an exception, but in any case it is not coming
-- back here, so turn on the flag.
if Present (Ent)
and then Ekind (Ent) = E_Procedure
and then No_Return (Ent)
then
Set_Trivial_Subprogram (Stm);
end if;
end;
end if;
end if;
end;
end;
-- Check for variables that are never modified
declare
E1 : Entity_Id;
E2 : Entity_Id;
begin
-- If there is a separate spec, then transfer Never_Set_In_Source
-- flags from out parameters to the corresponding entities in the
-- body. The reason we do that is we want to post error flags on
-- the body entities, not the spec entities.
if Present (Spec_Id) then
E1 := First_Entity (Spec_Id);
while Present (E1) loop
if Ekind (E1) = E_Out_Parameter then
E2 := First_Entity (Body_Id);
while Present (E2) loop
exit when Chars (E1) = Chars (E2);
Next_Entity (E2);
end loop;
if Present (E2) then
Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
end if;
end if;
Next_Entity (E1);
end loop;
end if;
-- Check references of the subprogram spec when we are dealing with
-- an expression function due to it having a generated body.
-- Otherwise, we simply check the formals of the subprogram body.
if Present (Spec_Id)
and then Is_Expression_Function (Spec_Id)
then
Check_References (Spec_Id);
else
Check_References (Body_Id);
end if;
end;
-- Check for nested subprogram, and mark outer level subprogram if so
declare
Ent : Entity_Id;
begin
if Present (Spec_Id) then
Ent := Spec_Id;
else
Ent := Body_Id;
end if;
loop
Ent := Enclosing_Subprogram (Ent);
exit when No (Ent) or else Is_Subprogram (Ent);
end loop;
if Present (Ent) then
Set_Has_Nested_Subprogram (Ent);
end if;
end;
-- Restore the limited views in the spec, if any, to let the back end
-- process it without running into circularities.
if Exch_Views /= No_Elist then
Restore_Limited_Views (Exch_Views);
end if;
if Mask_Types /= No_Elist then
Unmask_Unfrozen_Types (Mask_Types);
end if;
if Present (Desig_View) then
Set_Directly_Designated_Type (Etype (Spec_Id), Desig_View);
end if;
<<Leave>>
if Present (Ignored_Ghost_Region) then
Expander_Active := Saved_EA;
end if;
Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP;
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Analyze_Subprogram_Body_Helper;
------------------------------------
-- Analyze_Subprogram_Declaration --
------------------------------------
procedure Analyze_Subprogram_Declaration (N : Node_Id) is
Scop : constant Entity_Id := Current_Scope;
Designator : Entity_Id;
Is_Completion : Boolean;
-- Indicates whether a null procedure declaration is a completion
begin
-- Null procedures are not allowed in SPARK
if Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
then
-- Null procedures are allowed in protected types, following the
-- recent AI12-0147.
if Is_Protected_Type (Current_Scope)
and then Ada_Version < Ada_2012
then
Error_Msg_N ("protected operation cannot be a null procedure", N);
end if;
Analyze_Null_Procedure (N, Is_Completion);
-- The null procedure acts as a body, nothing further is needed
if Is_Completion then
return;
end if;
end if;
Designator := Analyze_Subprogram_Specification (Specification (N));
-- A reference may already have been generated for the unit name, in
-- which case the following call is redundant. However it is needed for
-- declarations that are the rewriting of an expression function.
Generate_Definition (Designator);
-- Set the SPARK mode from the current context (may be overwritten later
-- with explicit pragma). This is not done for entry barrier functions
-- because they are generated outside the protected type and should not
-- carry the mode of the enclosing context.
if Nkind (N) = N_Subprogram_Declaration
and then Is_Entry_Barrier_Function (N)
then
null;
else
Set_SPARK_Pragma (Designator, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Designator);
end if;
-- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in case
-- the body of this subprogram is instantiated or inlined later and out
-- of context. The body uses this attribute to restore the value of the
-- global flag.
if Ignore_SPARK_Mode_Pragmas_In_Instance then
Set_Ignore_SPARK_Mode_Pragmas (Designator);
end if;
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => Designator,
Checks => True,
Warnings => True);
if Debug_Flag_C then
Write_Str ("==> subprogram spec ");
Write_Name (Chars (Designator));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
Indent;
end if;
Validate_RCI_Subprogram_Declaration (N);
New_Overloaded_Entity (Designator);
Check_Delayed_Subprogram (Designator);
-- If the type of the first formal of the current subprogram is a non-
-- generic tagged private type, mark the subprogram as being a private
-- primitive. Ditto if this is a function with controlling result, and
-- the return type is currently private. In both cases, the type of the
-- controlling argument or result must be in the current scope for the
-- operation to be primitive.
if Has_Controlling_Result (Designator)
and then Is_Private_Type (Etype (Designator))
and then Scope (Etype (Designator)) = Current_Scope
and then not Is_Generic_Actual_Type (Etype (Designator))
then
Set_Is_Private_Primitive (Designator);
elsif Present (First_Formal (Designator)) then
declare
Formal_Typ : constant Entity_Id :=
Etype (First_Formal (Designator));
begin
Set_Is_Private_Primitive (Designator,
Is_Tagged_Type (Formal_Typ)
and then Scope (Formal_Typ) = Current_Scope
and then Is_Private_Type (Formal_Typ)
and then not Is_Generic_Actual_Type (Formal_Typ));
end;
end if;
-- Ada 2005 (AI-251): Abstract interface primitives must be abstract
-- or null.
if Ada_Version >= Ada_2005
and then Comes_From_Source (N)
and then Is_Dispatching_Operation (Designator)
then
declare
E : Entity_Id;
Etyp : Entity_Id;
begin
if Has_Controlling_Result (Designator) then
Etyp := Etype (Designator);
else
E := First_Entity (Designator);
while Present (E)
and then Is_Formal (E)
and then not Is_Controlling_Formal (E)
loop
Next_Entity (E);
end loop;
Etyp := Etype (E);
end if;
if Is_Access_Type (Etyp) then
Etyp := Directly_Designated_Type (Etyp);
end if;
if Is_Interface (Etyp)
and then not Is_Abstract_Subprogram (Designator)
and then not (Ekind (Designator) = E_Procedure
and then Null_Present (Specification (N)))
then
Error_Msg_Name_1 := Chars (Defining_Entity (N));
-- Specialize error message based on procedures vs. functions,
-- since functions can't be null subprograms.
if Ekind (Designator) = E_Procedure then
Error_Msg_N
("interface procedure % must be abstract or null", N);
else
Error_Msg_N
("interface function % must be abstract", N);
end if;
end if;
end;
end if;
-- For a compilation unit, set body required. This flag will only be
-- reset if a valid Import or Interface pragma is processed later on.
if Nkind (Parent (N)) = N_Compilation_Unit then
Set_Body_Required (Parent (N), True);
if Ada_Version >= Ada_2005
and then Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
then
Error_Msg_N
("null procedure cannot be declared at library level", N);
end if;
end if;
Generate_Reference_To_Formals (Designator);
Check_Eliminated (Designator);
if Debug_Flag_C then
Outdent;
Write_Str ("<== subprogram spec ");
Write_Name (Chars (Designator));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
end if;
-- Indicate that this is a protected operation, because it may be used
-- in subsequent declarations within the protected type.
if Is_Protected_Type (Current_Scope) then
Set_Convention (Designator, Convention_Protected);
end if;
List_Inherited_Pre_Post_Aspects (Designator);
-- Process the aspects before establishing the proper categorization in
-- case the subprogram is a compilation unit and one of its aspects is
-- converted into a categorization pragma.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Designator);
end if;
if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then
Set_Categorization_From_Scope (Designator, Scop);
-- Otherwise the unit is a compilation unit and/or a child unit. Set the
-- proper categorization of the unit based on its pragmas.
else
Push_Scope (Designator);
Set_Categorization_From_Pragmas (N);
Validate_Categorization_Dependency (N, Designator);
Pop_Scope;
end if;
end Analyze_Subprogram_Declaration;
--------------------------------------
-- Analyze_Subprogram_Specification --
--------------------------------------
-- Reminder: N here really is a subprogram specification (not a subprogram
-- declaration). This procedure is called to analyze the specification in
-- both subprogram bodies and subprogram declarations (specs).
function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is
function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean;
-- Determine whether entity E denotes the spec or body of an invariant
-- procedure.
------------------------------------
-- Is_Invariant_Procedure_Or_Body --
------------------------------------
function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean is
Decl : constant Node_Id := Unit_Declaration_Node (E);
Spec : Entity_Id;
begin
if Nkind (Decl) = N_Subprogram_Body then
Spec := Corresponding_Spec (Decl);
else
Spec := E;
end if;
return
Present (Spec)
and then Ekind (Spec) = E_Procedure
and then (Is_Partial_Invariant_Procedure (Spec)
or else Is_Invariant_Procedure (Spec));
end Is_Invariant_Procedure_Or_Body;
-- Local variables
Designator : constant Entity_Id := Defining_Entity (N);
Formals : constant List_Id := Parameter_Specifications (N);
-- Start of processing for Analyze_Subprogram_Specification
begin
-- Proceed with analysis. Do not emit a cross-reference entry if the
-- specification comes from an expression function, because it may be
-- the completion of a previous declaration. If it is not, the cross-
-- reference entry will be emitted for the new subprogram declaration.
if Nkind (Parent (N)) /= N_Expression_Function then
Generate_Definition (Designator);
end if;
if Nkind (N) = N_Function_Specification then
Mutate_Ekind (Designator, E_Function);
Set_Mechanism (Designator, Default_Mechanism);
else
Mutate_Ekind (Designator, E_Procedure);
Set_Etype (Designator, Standard_Void_Type);
end if;
-- Flag Is_Inlined_Always is True by default, and reversed to False for
-- those subprograms which could be inlined in GNATprove mode (because
-- Body_To_Inline is non-Empty) but should not be inlined.
if GNATprove_Mode then
Set_Is_Inlined_Always (Designator);
end if;
-- Introduce new scope for analysis of the formals and the return type
Set_Scope (Designator, Current_Scope);
if Present (Formals) then
Push_Scope (Designator);
Process_Formals (Formals, N);
-- Check dimensions in N for formals with default expression
Analyze_Dimension_Formals (N, Formals);
-- Ada 2005 (AI-345): If this is an overriding operation of an
-- inherited interface operation, and the controlling type is
-- a synchronized type, replace the type with its corresponding
-- record, to match the proper signature of an overriding operation.
-- Same processing for an access parameter whose designated type is
-- derived from a synchronized interface.
-- This modification is not done for invariant procedures because
-- the corresponding record may not necessarely be visible when the
-- concurrent type acts as the full view of a private type.
-- package Pack is
-- type Prot is private with Type_Invariant => ...;
-- procedure ConcInvariant (Obj : Prot);
-- private
-- protected type Prot is ...;
-- type Concurrent_Record_Prot is record ...;
-- procedure ConcInvariant (Obj : Prot) is
-- ...
-- end ConcInvariant;
-- end Pack;
-- In the example above, both the spec and body of the invariant
-- procedure must utilize the private type as the controlling type.
if Ada_Version >= Ada_2005
and then not Is_Invariant_Procedure_Or_Body (Designator)
then
declare
Formal : Entity_Id;
Formal_Typ : Entity_Id;
Rec_Typ : Entity_Id;
Desig_Typ : Entity_Id;
begin
Formal := First_Formal (Designator);
while Present (Formal) loop
Formal_Typ := Etype (Formal);
if Is_Concurrent_Type (Formal_Typ)
and then Present (Corresponding_Record_Type (Formal_Typ))
then
Rec_Typ := Corresponding_Record_Type (Formal_Typ);
if Present (Interfaces (Rec_Typ)) then
Set_Etype (Formal, Rec_Typ);
end if;
elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then
Desig_Typ := Designated_Type (Formal_Typ);
if Is_Concurrent_Type (Desig_Typ)
and then Present (Corresponding_Record_Type (Desig_Typ))
then
Rec_Typ := Corresponding_Record_Type (Desig_Typ);
if Present (Interfaces (Rec_Typ)) then
Set_Directly_Designated_Type (Formal_Typ, Rec_Typ);
end if;
end if;
end if;
Next_Formal (Formal);
end loop;
end;
end if;
End_Scope;
-- The subprogram scope is pushed and popped around the processing of
-- the return type for consistency with call above to Process_Formals
-- (which itself can call Analyze_Return_Type), and to ensure that any
-- itype created for the return type will be associated with the proper
-- scope.
elsif Nkind (N) = N_Function_Specification then
Push_Scope (Designator);
Analyze_Return_Type (N);
End_Scope;
end if;
-- Function case
if Nkind (N) = N_Function_Specification then
-- Deal with operator symbol case
if Nkind (Designator) = N_Defining_Operator_Symbol then
Valid_Operator_Definition (Designator);
end if;
May_Need_Actuals (Designator);
-- Ada 2005 (AI-251): If the return type is abstract, verify that
-- the subprogram is abstract also. This does not apply to renaming
-- declarations, where abstractness is inherited, and to subprogram
-- bodies generated for stream operations, which become renamings as
-- bodies.
-- In case of primitives associated with abstract interface types
-- the check is applied later (see Analyze_Subprogram_Declaration).
if Nkind (Original_Node (Parent (N))) not in
N_Abstract_Subprogram_Declaration |
N_Formal_Abstract_Subprogram_Declaration |
N_Subprogram_Renaming_Declaration
then
if Is_Abstract_Type (Etype (Designator)) then
Error_Msg_N
("function that returns abstract type must be abstract", N);
-- Ada 2012 (AI-0073): Extend this test to subprograms with an
-- access result whose designated type is abstract.
elsif Ada_Version >= Ada_2012
and then Nkind (Result_Definition (N)) = N_Access_Definition
and then
not Is_Class_Wide_Type (Designated_Type (Etype (Designator)))
and then Is_Abstract_Type (Designated_Type (Etype (Designator)))
then
Error_Msg_N
("function whose access result designates abstract type "
& "must be abstract", N);
end if;
end if;
end if;
return Designator;
end Analyze_Subprogram_Specification;
-----------------------
-- Check_Conformance --
-----------------------
procedure Check_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Ctype : Conformance_Type;
Errmsg : Boolean;
Conforms : out Boolean;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False;
Skip_Controlling_Formals : Boolean := False)
is
procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
-- Sets Conforms to False. If Errmsg is False, then that's all it does.
-- If Errmsg is True, then processing continues to post an error message
-- for conformance error on given node. Two messages are output. The
-- first message points to the previous declaration with a general "no
-- conformance" message. The second is the detailed reason, supplied as
-- Msg. The parameter N provide information for a possible & insertion
-- in the message, and also provides the location for posting the
-- message in the absence of a specified Err_Loc location.
function Conventions_Match (Id1, Id2 : Entity_Id) return Boolean;
-- True if the conventions of entities Id1 and Id2 match.
function Null_Exclusions_Match (F1, F2 : Entity_Id) return Boolean;
-- True if the null exclusions of two formals of anonymous access type
-- match.
-----------------------
-- Conformance_Error --
-----------------------
procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
Enode : Node_Id;
begin
Conforms := False;
if Errmsg then
if No (Err_Loc) then
Enode := N;
else
Enode := Err_Loc;
end if;
Error_Msg_Sloc := Sloc (Old_Id);
case Ctype is
when Type_Conformant =>
Error_Msg_N -- CODEFIX
("not type conformant with declaration#!", Enode);
when Mode_Conformant =>
if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
Error_Msg_N
("not mode conformant with operation inherited#!",
Enode);
else
Error_Msg_N
("not mode conformant with declaration#!", Enode);
end if;
when Subtype_Conformant =>
if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
Error_Msg_N
("not subtype conformant with operation inherited#!",
Enode);
else
Error_Msg_N
("not subtype conformant with declaration#!", Enode);
end if;
when Fully_Conformant =>
if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
Error_Msg_N -- CODEFIX
("not fully conformant with operation inherited#!",
Enode);
else
Error_Msg_N -- CODEFIX
("not fully conformant with declaration#!", Enode);
end if;
end case;
Error_Msg_NE (Msg, Enode, N);
end if;
end Conformance_Error;
-----------------------
-- Conventions_Match --
-----------------------
function Conventions_Match
(Id1 : Entity_Id;
Id2 : Entity_Id) return Boolean
is
begin
-- Ignore the conventions of anonymous access-to-subprogram types
-- and subprogram types because these are internally generated and
-- the only way these may receive a convention is if they inherit
-- the convention of a related subprogram.
if Ekind (Id1) in E_Anonymous_Access_Subprogram_Type
| E_Subprogram_Type
or else
Ekind (Id2) in E_Anonymous_Access_Subprogram_Type
| E_Subprogram_Type
then
return True;
-- Otherwise compare the conventions directly
else
return Convention (Id1) = Convention (Id2);
end if;
end Conventions_Match;
---------------------------
-- Null_Exclusions_Match --
---------------------------
function Null_Exclusions_Match (F1, F2 : Entity_Id) return Boolean is
begin
if not Is_Anonymous_Access_Type (Etype (F1))
or else not Is_Anonymous_Access_Type (Etype (F2))
then
return True;
end if;
-- AI12-0289-1: Case of controlling access parameter; False if the
-- partial view is untagged, the full view is tagged, and no explicit
-- "not null". Note that at this point, we're processing the package
-- body, so private/full types have been swapped. The Sloc test below
-- is to detect the (legal) case where F1 comes after the full type
-- declaration. This part is disabled pre-2005, because "not null" is
-- not allowed on those language versions.
if Ada_Version >= Ada_2005
and then Is_Controlling_Formal (F1)
and then not Null_Exclusion_Present (Parent (F1))
and then not Null_Exclusion_Present (Parent (F2))
then
declare
D : constant Entity_Id := Directly_Designated_Type (Etype (F1));
Partial_View_Of_Desig : constant Entity_Id :=
Incomplete_Or_Partial_View (D);
begin
return No (Partial_View_Of_Desig)
or else Is_Tagged_Type (Partial_View_Of_Desig)
or else Sloc (D) < Sloc (F1);
end;
-- Not a controlling parameter, or one or both views have an explicit
-- "not null".
else
return Null_Exclusion_Present (Parent (F1)) =
Null_Exclusion_Present (Parent (F2));
end if;
end Null_Exclusions_Match;
-- Local Variables
Old_Type : constant Entity_Id := Etype (Old_Id);
New_Type : constant Entity_Id := Etype (New_Id);
Old_Formal : Entity_Id;
New_Formal : Entity_Id;
Old_Formal_Base : Entity_Id;
New_Formal_Base : Entity_Id;
-- Start of processing for Check_Conformance
begin
Conforms := True;
-- We need a special case for operators, since they don't appear
-- explicitly.
if Ctype = Type_Conformant then
if Ekind (New_Id) = E_Operator
and then Operator_Matches_Spec (New_Id, Old_Id)
then
return;
end if;
end if;
-- If both are functions/operators, check return types conform
if Old_Type /= Standard_Void_Type
and then
New_Type /= Standard_Void_Type
then
-- If we are checking interface conformance we omit controlling
-- arguments and result, because we are only checking the conformance
-- of the remaining parameters.
if Has_Controlling_Result (Old_Id)
and then Has_Controlling_Result (New_Id)
and then Skip_Controlling_Formals
then
null;
elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
if Ctype >= Subtype_Conformant
and then not Predicates_Match (Old_Type, New_Type)
then
Conformance_Error
("\predicate of return type does not match!", New_Id);
else
Conformance_Error
("\return type does not match!", New_Id);
end if;
return;
end if;
-- Ada 2005 (AI-231): In case of anonymous access types check the
-- null-exclusion and access-to-constant attributes match.
if Ada_Version >= Ada_2005
and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type
and then
(Can_Never_Be_Null (Old_Type) /= Can_Never_Be_Null (New_Type)
or else Is_Access_Constant (Etype (Old_Type)) /=
Is_Access_Constant (Etype (New_Type)))
then
Conformance_Error ("\return type does not match!", New_Id);
return;
end if;
-- If either is a function/operator and the other isn't, error
elsif Old_Type /= Standard_Void_Type
or else New_Type /= Standard_Void_Type
then
Conformance_Error ("\functions can only match functions!", New_Id);
return;
end if;
-- In subtype conformant case, conventions must match (RM 6.3.1(16)).
-- If this is a renaming as body, refine error message to indicate that
-- the conflict is with the original declaration. If the entity is not
-- frozen, the conventions don't have to match, the one of the renamed
-- entity is inherited.
if Ctype >= Subtype_Conformant then
if not Conventions_Match (Old_Id, New_Id) then
if not Is_Frozen (New_Id) then
null;
elsif Present (Err_Loc)
and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
and then Present (Corresponding_Spec (Err_Loc))
then
Error_Msg_Name_1 := Chars (New_Id);
Error_Msg_Name_2 :=
Name_Ada + Convention_Id'Pos (Convention (New_Id));
Conformance_Error ("\prior declaration for% has convention %!");
return;
else
Conformance_Error ("\calling conventions do not match!");
return;
end if;
else
Check_Formal_Subprogram_Conformance
(New_Id, Old_Id, Err_Loc, Errmsg, Conforms);
if not Conforms then
return;
end if;
end if;
end if;
-- Deal with parameters
-- Note: we use the entity information, rather than going directly
-- to the specification in the tree. This is not only simpler, but
-- absolutely necessary for some cases of conformance tests between
-- operators, where the declaration tree simply does not exist.
Old_Formal := First_Formal (Old_Id);
New_Formal := First_Formal (New_Id);
while Present (Old_Formal) and then Present (New_Formal) loop
if Is_Controlling_Formal (Old_Formal)
and then Is_Controlling_Formal (New_Formal)
and then Skip_Controlling_Formals
then
-- The controlling formals will have different types when
-- comparing an interface operation with its match, but both
-- or neither must be access parameters.
if Is_Access_Type (Etype (Old_Formal))
=
Is_Access_Type (Etype (New_Formal))
then
goto Skip_Controlling_Formal;
else
Conformance_Error
("\access parameter does not match!", New_Formal);
end if;
end if;
-- Ada 2012: Mode conformance also requires that formal parameters
-- be both aliased, or neither.
if Ctype >= Mode_Conformant and then Ada_Version >= Ada_2012 then
if Is_Aliased (Old_Formal) /= Is_Aliased (New_Formal) then
Conformance_Error
("\aliased parameter mismatch!", New_Formal);
end if;
end if;
if Ctype = Fully_Conformant then
-- Names must match. Error message is more accurate if we do
-- this before checking that the types of the formals match.
if Chars (Old_Formal) /= Chars (New_Formal) then
Conformance_Error ("\name& does not match!", New_Formal);
-- Set error posted flag on new formal as well to stop
-- junk cascaded messages in some cases.
Set_Error_Posted (New_Formal);
return;
end if;
-- Null exclusion must match
if not Relaxed_RM_Semantics
and then not Null_Exclusions_Match (Old_Formal, New_Formal)
then
Conformance_Error
("\null exclusion for& does not match", New_Formal);
-- Mark error posted on the new formal to avoid duplicated
-- complaint about types not matching.
Set_Error_Posted (New_Formal);
end if;
end if;
-- Ada 2005 (AI-423): Possible access [sub]type and itype match. This
-- case occurs whenever a subprogram is being renamed and one of its
-- parameters imposes a null exclusion. For example:
-- type T is null record;
-- type Acc_T is access T;
-- subtype Acc_T_Sub is Acc_T;
-- procedure P (Obj : not null Acc_T_Sub); -- itype
-- procedure Ren_P (Obj : Acc_T_Sub) -- subtype
-- renames P;
Old_Formal_Base := Etype (Old_Formal);
New_Formal_Base := Etype (New_Formal);
if Get_Inst then
Old_Formal_Base := Get_Instance_Of (Old_Formal_Base);
New_Formal_Base := Get_Instance_Of (New_Formal_Base);
end if;
-- Types must always match. In the visible part of an instance,
-- usual overloading rules for dispatching operations apply, and
-- we check base types (not the actual subtypes).
if In_Instance_Visible_Part
and then Is_Dispatching_Operation (New_Id)
then
if not Conforming_Types
(T1 => Base_Type (Etype (Old_Formal)),
T2 => Base_Type (Etype (New_Formal)),
Ctype => Ctype,
Get_Inst => Get_Inst)
then
Conformance_Error ("\type of & does not match!", New_Formal);
return;
end if;
elsif not Conforming_Types
(T1 => Old_Formal_Base,
T2 => New_Formal_Base,
Ctype => Ctype,
Get_Inst => Get_Inst)
then
-- Don't give error message if old type is Any_Type. This test
-- avoids some cascaded errors, e.g. in case of a bad spec.
if Errmsg and then Old_Formal_Base = Any_Type then
Conforms := False;
else
if Ctype >= Subtype_Conformant
and then
not Predicates_Match (Old_Formal_Base, New_Formal_Base)
then
Conformance_Error
("\predicate of & does not match!", New_Formal);
else
Conformance_Error
("\type of & does not match!", New_Formal);
if not Dimensions_Match (Old_Formal_Base, New_Formal_Base)
then
Error_Msg_N ("\dimensions mismatch!", New_Formal);
end if;
end if;
end if;
return;
end if;
-- For mode conformance, mode must match
if Ctype >= Mode_Conformant then
if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then
if Ekind (New_Id) not in E_Function | E_Procedure
or else not Is_Primitive_Wrapper (New_Id)
then
Conformance_Error ("\mode of & does not match!", New_Formal);
else
declare
T : constant Entity_Id := Find_Dispatching_Type (New_Id);
begin
if Is_Protected_Type (Corresponding_Concurrent_Type (T))
then
Conforms := False;
if Errmsg then
Error_Msg_PT (New_Id, Ultimate_Alias (Old_Id));
end if;
else
Conformance_Error
("\mode of & does not match!", New_Formal);
end if;
end;
end if;
return;
elsif Is_Access_Type (Old_Formal_Base)
and then Is_Access_Type (New_Formal_Base)
and then Is_Access_Constant (Old_Formal_Base) /=
Is_Access_Constant (New_Formal_Base)
then
Conformance_Error
("\constant modifier does not match!", New_Formal);
return;
end if;
end if;
if Ctype >= Subtype_Conformant then
-- Ada 2005 (AI-231): In case of anonymous access types check
-- the null-exclusion and access-to-constant attributes must
-- match. For null exclusion, we test the types rather than the
-- formals themselves, since the attribute is only set reliably
-- on the formals in the Ada 95 case, and we exclude the case
-- where Old_Formal is marked as controlling, to avoid errors
-- when matching completing bodies with dispatching declarations
-- (access formals in the bodies aren't marked Can_Never_Be_Null).
if Ada_Version >= Ada_2005
and then Is_Anonymous_Access_Type (Etype (Old_Formal))
and then Is_Anonymous_Access_Type (Etype (New_Formal))
and then
((Can_Never_Be_Null (Etype (Old_Formal)) /=
Can_Never_Be_Null (Etype (New_Formal))
and then
not Is_Controlling_Formal (Old_Formal))
or else
Is_Access_Constant (Etype (Old_Formal)) /=
Is_Access_Constant (Etype (New_Formal)))
-- Do not complain if error already posted on New_Formal. This
-- avoids some redundant error messages.
and then not Error_Posted (New_Formal)
then
-- It is allowed to omit the null-exclusion in case of stream
-- attribute subprograms. We recognize stream subprograms
-- through their TSS-generated suffix.
declare
TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id);
begin
if TSS_Name /= TSS_Stream_Read
and then TSS_Name /= TSS_Stream_Write
and then TSS_Name /= TSS_Stream_Input
and then TSS_Name /= TSS_Stream_Output
then
-- Here we have a definite conformance error. It is worth
-- special casing the error message for the case of a
-- controlling formal (which excludes null).
if Is_Controlling_Formal (New_Formal) then
Error_Msg_Node_2 := Scope (New_Formal);
Conformance_Error
("\controlling formal & of & excludes null, "
& "declaration must exclude null as well",
New_Formal);
-- Normal case (couldn't we give more detail here???)
else
Conformance_Error
("\type of & does not match!", New_Formal);
end if;
return;
end if;
end;
end if;
end if;
-- Full conformance checks
if Ctype = Fully_Conformant then
-- We have checked already that names match
if Parameter_Mode (Old_Formal) = E_In_Parameter then
-- Check default expressions for in parameters
declare
NewD : constant Boolean :=
Present (Default_Value (New_Formal));
OldD : constant Boolean :=
Present (Default_Value (Old_Formal));
begin
if NewD or OldD then
-- The old default value has been analyzed because the
-- current full declaration will have frozen everything
-- before. The new default value has not been analyzed,
-- so analyze it now before we check for conformance.
if NewD then
Push_Scope (New_Id);
Preanalyze_Spec_Expression
(Default_Value (New_Formal), Etype (New_Formal));
End_Scope;
end if;
if not (NewD and OldD)
or else not Fully_Conformant_Expressions
(Default_Value (Old_Formal),
Default_Value (New_Formal))
then
Conformance_Error
("\default expression for & does not match!",
New_Formal);
return;
end if;
end if;
end;
end if;
end if;
-- A couple of special checks for Ada 83 mode. These checks are
-- skipped if either entity is an operator in package Standard,
-- or if either old or new instance is not from the source program.
if Ada_Version = Ada_83
and then Sloc (Old_Id) > Standard_Location
and then Sloc (New_Id) > Standard_Location
and then Comes_From_Source (Old_Id)
and then Comes_From_Source (New_Id)
then
declare
Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
New_Param : constant Node_Id := Declaration_Node (New_Formal);
begin
-- Explicit IN must be present or absent in both cases. This
-- test is required only in the full conformance case.
if In_Present (Old_Param) /= In_Present (New_Param)
and then Ctype = Fully_Conformant
then
Conformance_Error
("\(Ada 83) IN must appear in both declarations",
New_Formal);
return;
end if;
-- Grouping (use of comma in param lists) must be the same
-- This is where we catch a misconformance like:
-- A, B : Integer
-- A : Integer; B : Integer
-- which are represented identically in the tree except
-- for the setting of the flags More_Ids and Prev_Ids.
if More_Ids (Old_Param) /= More_Ids (New_Param)
or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
then
Conformance_Error
("\grouping of & does not match!", New_Formal);
return;
end if;
end;
end if;
-- This label is required when skipping controlling formals
<<Skip_Controlling_Formal>>
Next_Formal (Old_Formal);
Next_Formal (New_Formal);
end loop;
if Present (Old_Formal) then
Conformance_Error ("\too few parameters!");
return;
elsif Present (New_Formal) then
Conformance_Error ("\too many parameters!", New_Formal);
return;
end if;
end Check_Conformance;
-----------------------
-- Check_Conventions --
-----------------------
procedure Check_Conventions (Typ : Entity_Id) is
Ifaces_List : Elist_Id;
procedure Check_Convention (Op : Entity_Id);
-- Verify that the convention of inherited dispatching operation Op is
-- consistent among all subprograms it overrides. In order to minimize
-- the search, Search_From is utilized to designate a specific point in
-- the list rather than iterating over the whole list once more.
----------------------
-- Check_Convention --
----------------------
procedure Check_Convention (Op : Entity_Id) is
Op_Conv : constant Convention_Id := Convention (Op);
Iface_Conv : Convention_Id;
Iface_Elmt : Elmt_Id;
Iface_Prim_Elmt : Elmt_Id;
Iface_Prim : Entity_Id;
begin
Iface_Elmt := First_Elmt (Ifaces_List);
while Present (Iface_Elmt) loop
Iface_Prim_Elmt :=
First_Elmt (Primitive_Operations (Node (Iface_Elmt)));
while Present (Iface_Prim_Elmt) loop
Iface_Prim := Node (Iface_Prim_Elmt);
Iface_Conv := Convention (Iface_Prim);
if Is_Interface_Conformant (Typ, Iface_Prim, Op)
and then Iface_Conv /= Op_Conv
then
Error_Msg_N
("inconsistent conventions in primitive operations", Typ);
Error_Msg_Name_1 := Chars (Op);
Error_Msg_Name_2 := Get_Convention_Name (Op_Conv);
Error_Msg_Sloc := Sloc (Op);
if Comes_From_Source (Op) or else No (Alias (Op)) then
if not Present (Overridden_Operation (Op)) then
Error_Msg_N ("\\primitive % defined #", Typ);
else
Error_Msg_N
("\\overriding operation % with "
& "convention % defined #", Typ);
end if;
else pragma Assert (Present (Alias (Op)));
Error_Msg_Sloc := Sloc (Alias (Op));
Error_Msg_N ("\\inherited operation % with "
& "convention % defined #", Typ);
end if;
Error_Msg_Name_1 := Chars (Op);
Error_Msg_Name_2 := Get_Convention_Name (Iface_Conv);
Error_Msg_Sloc := Sloc (Iface_Prim);
Error_Msg_N ("\\overridden operation % with "
& "convention % defined #", Typ);
-- Avoid cascading errors
return;
end if;
Next_Elmt (Iface_Prim_Elmt);
end loop;
Next_Elmt (Iface_Elmt);
end loop;
end Check_Convention;
-- Local variables
Prim_Op : Entity_Id;
Prim_Op_Elmt : Elmt_Id;
-- Start of processing for Check_Conventions
begin
if not Has_Interfaces (Typ) then
return;
end if;
Collect_Interfaces (Typ, Ifaces_List);
-- The algorithm checks every overriding dispatching operation against
-- all the corresponding overridden dispatching operations, detecting
-- differences in conventions.
Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ));
while Present (Prim_Op_Elmt) loop
Prim_Op := Node (Prim_Op_Elmt);
-- A small optimization: skip the predefined dispatching operations
-- since they always have the same convention.
if not Is_Predefined_Dispatching_Operation (Prim_Op) then
Check_Convention (Prim_Op);
end if;
Next_Elmt (Prim_Op_Elmt);
end loop;
end Check_Conventions;
------------------------------
-- Check_Delayed_Subprogram --
------------------------------
procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
procedure Possible_Freeze (T : Entity_Id);
-- T is the type of either a formal parameter or of the return type. If
-- T is not yet frozen and needs a delayed freeze, then the subprogram
-- itself must be delayed.
---------------------
-- Possible_Freeze --
---------------------
procedure Possible_Freeze (T : Entity_Id) is
Scop : constant Entity_Id := Scope (Designator);
begin
-- If the subprogram appears within a package instance (which may be
-- the wrapper package of a subprogram instance) the freeze node for
-- that package will freeze the subprogram at the proper place, so
-- do not emit a freeze node for the subprogram, given that it may
-- appear in the wrong scope.
if Ekind (Scop) = E_Package
and then not Comes_From_Source (Scop)
and then Is_Generic_Instance (Scop)
then
null;
elsif Has_Delayed_Freeze (T) and then not Is_Frozen (T) then
Set_Has_Delayed_Freeze (Designator);
elsif Is_Access_Type (T)
and then Has_Delayed_Freeze (Designated_Type (T))
and then not Is_Frozen (Designated_Type (T))
then
Set_Has_Delayed_Freeze (Designator);
end if;
end Possible_Freeze;
-- Local variables
F : Entity_Id;
-- Start of processing for Check_Delayed_Subprogram
begin
-- All subprograms, including abstract subprograms, may need a freeze
-- node if some formal type or the return type needs one.
Possible_Freeze (Etype (Designator));
Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
-- Need delayed freeze if any of the formal types themselves need a
-- delayed freeze and are not yet frozen.
F := First_Formal (Designator);
while Present (F) loop
Possible_Freeze (Etype (F));
Possible_Freeze (Base_Type (Etype (F))); -- needed ???
Next_Formal (F);
end loop;
-- Mark functions that return by reference. Note that it cannot be done
-- for delayed_freeze subprograms because the underlying returned type
-- may not be known yet (for private types).
if not Has_Delayed_Freeze (Designator) and then Expander_Active then
Compute_Returns_By_Ref (Designator);
end if;
end Check_Delayed_Subprogram;
------------------------------------
-- Check_Discriminant_Conformance --
------------------------------------
procedure Check_Discriminant_Conformance
(N : Node_Id;
Prev : Entity_Id;
Prev_Loc : Node_Id)
is
Old_Discr : Entity_Id := First_Discriminant (Prev);
New_Discr : Node_Id := First (Discriminant_Specifications (N));
New_Discr_Id : Entity_Id;
New_Discr_Type : Entity_Id;
procedure Conformance_Error (Msg : String; N : Node_Id);
-- Post error message for conformance error on given node. Two messages
-- are output. The first points to the previous declaration with a
-- general "no conformance" message. The second is the detailed reason,
-- supplied as Msg. The parameter N provide information for a possible
-- & insertion in the message.
-----------------------
-- Conformance_Error --
-----------------------
procedure Conformance_Error (Msg : String; N : Node_Id) is
begin
Error_Msg_Sloc := Sloc (Prev_Loc);
Error_Msg_N -- CODEFIX
("not fully conformant with declaration#!", N);
Error_Msg_NE (Msg, N, N);
end Conformance_Error;
-- Start of processing for Check_Discriminant_Conformance
begin
while Present (Old_Discr) and then Present (New_Discr) loop
New_Discr_Id := Defining_Identifier (New_Discr);
-- The subtype mark of the discriminant on the full type has not
-- been analyzed so we do it here. For an access discriminant a new
-- type is created.
if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
New_Discr_Type :=
Access_Definition (N, Discriminant_Type (New_Discr));
else
Find_Type (Discriminant_Type (New_Discr));
New_Discr_Type := Etype (Discriminant_Type (New_Discr));
-- Ada 2005: if the discriminant definition carries a null
-- exclusion, create an itype to check properly for consistency
-- with partial declaration.
if Is_Access_Type (New_Discr_Type)
and then Null_Exclusion_Present (New_Discr)
then
New_Discr_Type :=
Create_Null_Excluding_Itype
(T => New_Discr_Type,
Related_Nod => New_Discr,
Scope_Id => Current_Scope);
end if;
end if;
if not Conforming_Types
(Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
then
Conformance_Error ("type of & does not match!", New_Discr_Id);
return;
else
-- Treat the new discriminant as an occurrence of the old one,
-- for navigation purposes, and fill in some semantic
-- information, for completeness.
Generate_Reference (Old_Discr, New_Discr_Id, 'r');
Set_Etype (New_Discr_Id, Etype (Old_Discr));
Set_Scope (New_Discr_Id, Scope (Old_Discr));
end if;
-- Names must match
if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
Conformance_Error ("name & does not match!", New_Discr_Id);
return;
end if;
-- Default expressions must match
declare
NewD : constant Boolean :=
Present (Expression (New_Discr));
OldD : constant Boolean :=
Present (Expression (Parent (Old_Discr)));
begin
if NewD or OldD then
-- The old default value has been analyzed and expanded,
-- because the current full declaration will have frozen
-- everything before. The new default values have not been
-- expanded, so expand now to check conformance.
if NewD then
Preanalyze_Spec_Expression
(Expression (New_Discr), New_Discr_Type);
end if;
if not (NewD and OldD)
or else not Fully_Conformant_Expressions
(Expression (Parent (Old_Discr)),
Expression (New_Discr))
then
Conformance_Error
("default expression for & does not match!",
New_Discr_Id);
return;
end if;
end if;
end;
-- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
if Ada_Version = Ada_83 then
declare
Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
begin
-- Grouping (use of comma in param lists) must be the same
-- This is where we catch a misconformance like:
-- A, B : Integer
-- A : Integer; B : Integer
-- which are represented identically in the tree except
-- for the setting of the flags More_Ids and Prev_Ids.
if More_Ids (Old_Disc) /= More_Ids (New_Discr)
or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
then
Conformance_Error
("grouping of & does not match!", New_Discr_Id);
return;
end if;
end;
end if;
Next_Discriminant (Old_Discr);
Next (New_Discr);
end loop;
if Present (Old_Discr) then
Conformance_Error ("too few discriminants!", Defining_Identifier (N));
return;
elsif Present (New_Discr) then
Conformance_Error
("too many discriminants!", Defining_Identifier (New_Discr));
return;
end if;
end Check_Discriminant_Conformance;
-----------------------------------------
-- Check_Formal_Subprogram_Conformance --
-----------------------------------------
procedure Check_Formal_Subprogram_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id;
Errmsg : Boolean;
Conforms : out Boolean)
is
N : Node_Id;
begin
Conforms := True;
if Is_Formal_Subprogram (Old_Id)
or else Is_Formal_Subprogram (New_Id)
or else (Is_Subprogram (New_Id)
and then Present (Alias (New_Id))
and then Is_Formal_Subprogram (Alias (New_Id)))
then
if Present (Err_Loc) then
N := Err_Loc;
else
N := New_Id;
end if;
Conforms := False;
if Errmsg then
Error_Msg_Sloc := Sloc (Old_Id);
Error_Msg_N ("not subtype conformant with declaration#!", N);
Error_Msg_NE
("\formal subprograms are not subtype conformant "
& "(RM 6.3.1 (17/3))", N, New_Id);
end if;
end if;
end Check_Formal_Subprogram_Conformance;
procedure Check_Formal_Subprogram_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Ignore : Boolean;
begin
Check_Formal_Subprogram_Conformance
(New_Id, Old_Id, Err_Loc, True, Ignore);
end Check_Formal_Subprogram_Conformance;
----------------------------
-- Check_Fully_Conformant --
----------------------------
procedure Check_Fully_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
end Check_Fully_Conformant;
--------------------------
-- Check_Limited_Return --
--------------------------
procedure Check_Limited_Return
(N : Node_Id;
Expr : Node_Id;
R_Type : Entity_Id)
is
begin
-- Ada 2005 (AI-318-02): Return-by-reference types have been removed and
-- replaced by anonymous access results. This is an incompatibility with
-- Ada 95. Not clear whether this should be enforced yet or perhaps
-- controllable with special switch. ???
-- A limited interface that is not immutably limited is OK
if Is_Limited_Interface (R_Type)
and then not Is_Concurrent_Interface (R_Type)
then
null;
elsif Is_Limited_Type (R_Type)
and then not Is_Interface (R_Type)
and then not (Nkind (N) = N_Simple_Return_Statement
and then Comes_From_Extended_Return_Statement (N))
and then not In_Instance_Body
and then not OK_For_Limited_Init_In_05 (R_Type, Expr)
then
-- Error in Ada 2005
if Ada_Version >= Ada_2005
and then not Debug_Flag_Dot_L
and then not GNAT_Mode
then
Error_Msg_N
("(Ada 2005) cannot copy object of a limited type "
& "(RM-2005 6.5(5.5/2))", Expr);
if Is_Limited_View (R_Type) then
Error_Msg_N
("\return by reference not permitted in Ada 2005", Expr);
end if;
-- Warn in Ada 95 mode, to give folks a heads up about this
-- incompatibility.
-- In GNAT mode, this is just a warning, to allow it to be evilly
-- turned off. Otherwise it is a real error.
-- In a generic context, simplify the warning because it makes no
-- sense to discuss pass-by-reference or copy.
elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then
if Inside_A_Generic then
Error_Msg_N
("return of limited object not permitted in Ada 2005 "
& "(RM-2005 6.5(5.5/2))?y?", Expr);
elsif Is_Limited_View (R_Type) then
Error_Msg_N
("return by reference not permitted in Ada 2005 "
& "(RM-2005 6.5(5.5/2))?y?", Expr);
else
Error_Msg_N
("cannot copy object of a limited type in Ada 2005 "
& "(RM-2005 6.5(5.5/2))?y?", Expr);
end if;
-- Ada 95 mode, and compatibility warnings disabled
else
pragma Assert (Ada_Version <= Ada_95);
pragma Assert (not (Warn_On_Ada_2005_Compatibility or GNAT_Mode));
return; -- skip continuation messages below
end if;
if not Inside_A_Generic then
Error_Msg_N
("\consider switching to return of access type", Expr);
Explain_Limited_Type (R_Type, Expr);
end if;
end if;
end Check_Limited_Return;
---------------------------
-- Check_Mode_Conformant --
---------------------------
procedure Check_Mode_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
end Check_Mode_Conformant;
--------------------------------
-- Check_Overriding_Indicator --
--------------------------------
procedure Check_Overriding_Indicator
(Subp : Entity_Id;
Overridden_Subp : Entity_Id;
Is_Primitive : Boolean)
is
Decl : Node_Id;
Spec : Node_Id;
begin
-- No overriding indicator for literals
if Ekind (Subp) = E_Enumeration_Literal then
return;
elsif Ekind (Subp) = E_Entry then
Decl := Parent (Subp);
-- No point in analyzing a malformed operator
elsif Nkind (Subp) = N_Defining_Operator_Symbol
and then Error_Posted (Subp)
then
return;
else
Decl := Unit_Declaration_Node (Subp);
end if;
if Nkind (Decl) in N_Subprogram_Body
| N_Subprogram_Body_Stub
| N_Subprogram_Declaration
| N_Abstract_Subprogram_Declaration
| N_Subprogram_Renaming_Declaration
then
Spec := Specification (Decl);
elsif Nkind (Decl) = N_Entry_Declaration then
Spec := Decl;
else
return;
end if;
-- An overriding indication is illegal on a subprogram declared
-- in a protected body, where there is no operation to override.
if (Must_Override (Spec) or else Must_Not_Override (Spec))
and then Is_List_Member (Decl)
and then Present (Parent (List_Containing (Decl)))
and then Nkind (Parent (List_Containing (Decl))) = N_Protected_Body
then
Error_Msg_N
("illegal overriding indication in protected body", Decl);
return;
end if;
-- The overriding operation is type conformant with the overridden one,
-- but the names of the formals are not required to match. If the names
-- appear permuted in the overriding operation, this is a possible
-- source of confusion that is worth diagnosing. Controlling formals
-- often carry names that reflect the type, and it is not worthwhile
-- requiring that their names match.
if Present (Overridden_Subp)
and then Nkind (Subp) /= N_Defining_Operator_Symbol
then
declare
Form1 : Entity_Id;
Form2 : Entity_Id;
begin
Form1 := First_Formal (Subp);
Form2 := First_Formal (Overridden_Subp);
-- If the overriding operation is a synchronized operation, skip
-- the first parameter of the overridden operation, which is
-- implicit in the new one. If the operation is declared in the
-- body it is not primitive and all formals must match.
if Is_Concurrent_Type (Scope (Subp))
and then Is_Tagged_Type (Scope (Subp))
and then not Has_Completion (Scope (Subp))
then
Form2 := Next_Formal (Form2);
end if;
if Present (Form1) then
Form1 := Next_Formal (Form1);
Form2 := Next_Formal (Form2);
end if;
while Present (Form1) loop
if not Is_Controlling_Formal (Form1)
and then Present (Next_Formal (Form2))
and then Chars (Form1) = Chars (Next_Formal (Form2))
then
Error_Msg_Node_2 := Alias (Overridden_Subp);
Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
Error_Msg_NE
("& does not match corresponding formal of&#",
Form1, Form1);
exit;
end if;
Next_Formal (Form1);
Next_Formal (Form2);
end loop;
end;
end if;
-- If there is an overridden subprogram, then check that there is no
-- "not overriding" indicator, and mark the subprogram as overriding.
-- This is not done if the overridden subprogram is marked as hidden,
-- which can occur for the case of inherited controlled operations
-- (see Derive_Subprogram), unless the inherited subprogram's parent
-- subprogram is not itself hidden or we are within a generic instance,
-- in which case the hidden flag may have been modified for the
-- expansion of the instance.
-- (Note: This condition could probably be simplified, leaving out the
-- testing for the specific controlled cases, but it seems safer and
-- clearer this way, and echoes similar special-case tests of this
-- kind in other places.)
if Present (Overridden_Subp)
and then (not Is_Hidden (Overridden_Subp)
or else
(Chars (Overridden_Subp) in Name_Initialize
| Name_Adjust
| Name_Finalize
and then Present (Alias (Overridden_Subp))
and then (not Is_Hidden (Alias (Overridden_Subp))
or else In_Instance)))
then
if Must_Not_Override (Spec) then
Error_Msg_Sloc := Sloc (Overridden_Subp);
if Ekind (Subp) = E_Entry then
Error_Msg_NE
("entry & overrides inherited operation #", Spec, Subp);
else
Error_Msg_NE
("subprogram & overrides inherited operation #", Spec, Subp);
end if;
-- Special-case to fix a GNAT oddity: Limited_Controlled is declared
-- as an extension of Root_Controlled, and thus has a useless Adjust
-- operation. This operation should not be inherited by other limited
-- controlled types. An explicit Adjust for them is not overriding.
elsif Must_Override (Spec)
and then Chars (Overridden_Subp) = Name_Adjust
and then Is_Limited_Type (Etype (First_Formal (Subp)))
and then Present (Alias (Overridden_Subp))
and then In_Predefined_Unit (Alias (Overridden_Subp))
then
Get_Name_String
(Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp))));
Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
elsif Is_Subprogram (Subp) then
if Is_Init_Proc (Subp) then
null;
elsif No (Overridden_Operation (Subp)) then
-- For entities generated by Derive_Subprograms the overridden
-- operation is the inherited primitive (which is available
-- through the attribute alias)
if (Is_Dispatching_Operation (Subp)
or else Is_Dispatching_Operation (Overridden_Subp))
and then not Comes_From_Source (Overridden_Subp)
and then Find_Dispatching_Type (Overridden_Subp) =
Find_Dispatching_Type (Subp)
and then Present (Alias (Overridden_Subp))
and then Comes_From_Source (Alias (Overridden_Subp))
then
Set_Overridden_Operation (Subp, Alias (Overridden_Subp));
Inherit_Subprogram_Contract (Subp, Alias (Overridden_Subp));
Set_Is_Ada_2022_Only (Subp,
Is_Ada_2022_Only (Alias (Overridden_Subp)));
else
Set_Overridden_Operation (Subp, Overridden_Subp);
Inherit_Subprogram_Contract (Subp, Overridden_Subp);
Set_Is_Ada_2022_Only (Subp,
Is_Ada_2022_Only (Overridden_Subp));
end if;
end if;
end if;
-- If primitive flag is set or this is a protected operation, then
-- the operation is overriding at the point of its declaration, so
-- warn if necessary. Otherwise it may have been declared before the
-- operation it overrides and no check is required.
if Style_Check
and then not Must_Override (Spec)
and then (Is_Primitive
or else Ekind (Scope (Subp)) = E_Protected_Type)
then
Style.Missing_Overriding (Decl, Subp);
end if;
-- If Subp is an operator, it may override a predefined operation, if
-- it is defined in the same scope as the type to which it applies.
-- In that case Overridden_Subp is empty because of our implicit
-- representation for predefined operators. We have to check whether the
-- signature of Subp matches that of a predefined operator. Note that
-- first argument provides the name of the operator, and the second
-- argument the signature that may match that of a standard operation.
-- If the indicator is overriding, then the operator must match a
-- predefined signature, because we know already that there is no
-- explicit overridden operation.
elsif Chars (Subp) in Any_Operator_Name then
if Must_Not_Override (Spec) then
-- If this is not a primitive or a protected subprogram, then
-- "not overriding" is illegal.
if not Is_Primitive
and then Ekind (Scope (Subp)) /= E_Protected_Type
then
Error_Msg_N ("overriding indicator only allowed "
& "if subprogram is primitive", Subp);
elsif Can_Override_Operator (Subp) then
Error_Msg_NE
("subprogram& overrides predefined operator", Spec, Subp);
end if;
elsif Must_Override (Spec) then
if No (Overridden_Operation (Subp))
and then not Can_Override_Operator (Subp)
then
Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
end if;
elsif not Error_Posted (Subp)
and then Style_Check
and then Can_Override_Operator (Subp)
and then not In_Predefined_Unit (Subp)
then
-- If style checks are enabled, indicate that the indicator is
-- missing. However, at the point of declaration, the type of
-- which this is a primitive operation may be private, in which
-- case the indicator would be premature.
if Has_Private_Declaration (Etype (Subp))
or else Has_Private_Declaration (Etype (First_Formal (Subp)))
then
null;
else
Style.Missing_Overriding (Decl, Subp);
end if;
end if;
elsif Must_Override (Spec) then
if Ekind (Subp) = E_Entry then
Error_Msg_NE ("entry & is not overriding", Spec, Subp);
else
Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
end if;
-- If the operation is marked "not overriding" and it's not primitive
-- then an error is issued, unless this is an operation of a task or
-- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding"
-- has been specified have already been checked above.
elsif Must_Not_Override (Spec)
and then not Is_Primitive
and then Ekind (Subp) /= E_Entry
and then Ekind (Scope (Subp)) /= E_Protected_Type
then
Error_Msg_N
("overriding indicator only allowed if subprogram is primitive",
Subp);
return;
end if;
end Check_Overriding_Indicator;
-------------------
-- Check_Returns --
-------------------
-- Note: this procedure needs to know far too much about how the expander
-- messes with exceptions. The use of the flag Exception_Junk and the
-- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers
-- works, but is not very clean. It would be better if the expansion
-- routines would leave Original_Node working nicely, and we could use
-- Original_Node here to ignore all the peculiar expander messing ???
procedure Check_Returns
(HSS : Node_Id;
Mode : Character;
Err : out Boolean;
Proc : Entity_Id := Empty)
is
Handler : Node_Id;
procedure Check_Statement_Sequence (L : List_Id);
-- Internal recursive procedure to check a list of statements for proper
-- termination by a return statement (or a transfer of control or a
-- compound statement that is itself internally properly terminated).
------------------------------
-- Check_Statement_Sequence --
------------------------------
procedure Check_Statement_Sequence (L : List_Id) is
Last_Stm : Node_Id;
Stm : Node_Id;
Kind : Node_Kind;
function Assert_False return Boolean;
-- Returns True if Last_Stm is a pragma Assert (False) that has been
-- rewritten as a null statement when assertions are off. The assert
-- is not active, but it is still enough to kill the warning.
------------------
-- Assert_False --
------------------
function Assert_False return Boolean is
Orig : constant Node_Id := Original_Node (Last_Stm);
begin
if Nkind (Orig) = N_Pragma
and then Pragma_Name (Orig) = Name_Assert
and then not Error_Posted (Orig)
then
declare
Arg : constant Node_Id :=
First (Pragma_Argument_Associations (Orig));
Exp : constant Node_Id := Expression (Arg);
begin
return Nkind (Exp) = N_Identifier
and then Chars (Exp) = Name_False;
end;
else
return False;
end if;
end Assert_False;
-- Local variables
Raise_Exception_Call : Boolean;
-- Set True if statement sequence terminated by Raise_Exception call
-- or a Reraise_Occurrence call.
-- Start of processing for Check_Statement_Sequence
begin
Raise_Exception_Call := False;
-- Get last real statement
Last_Stm := Last (L);
-- Deal with digging out exception handler statement sequences that
-- have been transformed by the local raise to goto optimization.
-- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this
-- optimization has occurred, we are looking at something like:
-- begin
-- original stmts in block
-- exception \
-- when excep1 => |
-- goto L1; | omitted if No_Exception_Propagation
-- when excep2 => |
-- goto L2; /
-- end;
-- goto L3; -- skip handler when exception not raised
-- <<L1>> -- target label for local exception
-- begin
-- estmts1
-- end;
-- goto L3;
-- <<L2>>
-- begin
-- estmts2
-- end;
-- <<L3>>
-- and what we have to do is to dig out the estmts1 and estmts2
-- sequences (which were the original sequences of statements in
-- the exception handlers) and check them.
if Nkind (Last_Stm) = N_Label and then Exception_Junk (Last_Stm) then
Stm := Last_Stm;
loop
Prev (Stm);
exit when No (Stm);
exit when Nkind (Stm) /= N_Block_Statement;
exit when not Exception_Junk (Stm);
Prev (Stm);
exit when No (Stm);
exit when Nkind (Stm) /= N_Label;
exit when not Exception_Junk (Stm);
Check_Statement_Sequence
(Statements (Handled_Statement_Sequence (Next (Stm))));
Prev (Stm);
Last_Stm := Stm;
exit when No (Stm);
exit when Nkind (Stm) /= N_Goto_Statement;
exit when not Exception_Junk (Stm);
end loop;
end if;
-- Don't count pragmas
while Nkind (Last_Stm) = N_Pragma
-- Don't count call to SS_Release (can happen after Raise_Exception)
or else
(Nkind (Last_Stm) = N_Procedure_Call_Statement
and then
Nkind (Name (Last_Stm)) = N_Identifier
and then
Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
-- Don't count exception junk
or else
(Nkind (Last_Stm) in
N_Goto_Statement | N_Label | N_Object_Declaration
and then Exception_Junk (Last_Stm))
or else Nkind (Last_Stm) in N_Push_xxx_Label | N_Pop_xxx_Label
-- Inserted code, such as finalization calls, is irrelevant: we only
-- need to check original source.
or else Is_Rewrite_Insertion (Last_Stm)
loop
Prev (Last_Stm);
end loop;
-- Here we have the "real" last statement
Kind := Nkind (Last_Stm);
-- Transfer of control, OK. Note that in the No_Return procedure
-- case, we already diagnosed any explicit return statements, so
-- we can treat them as OK in this context.
if Is_Transfer (Last_Stm) then
return;
-- Check cases of explicit non-indirect procedure calls
elsif Kind = N_Procedure_Call_Statement
and then Is_Entity_Name (Name (Last_Stm))
then
-- Check call to Raise_Exception procedure which is treated
-- specially, as is a call to Reraise_Occurrence.
-- We suppress the warning in these cases since it is likely that
-- the programmer really does not expect to deal with the case
-- of Null_Occurrence, and thus would find a warning about a
-- missing return curious, and raising Program_Error does not
-- seem such a bad behavior if this does occur.
-- Note that in the Ada 2005 case for Raise_Exception, the actual
-- behavior will be to raise Constraint_Error (see AI-329).
if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
or else
Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
then
Raise_Exception_Call := True;
-- For Raise_Exception call, test first argument, if it is
-- an attribute reference for a 'Identity call, then we know
-- that the call cannot possibly return.
declare
Arg : constant Node_Id :=
Original_Node (First_Actual (Last_Stm));
begin
if Nkind (Arg) = N_Attribute_Reference
and then Attribute_Name (Arg) = Name_Identity
then
return;
end if;
end;
end if;
-- If statement, need to look inside if there is an else and check
-- each constituent statement sequence for proper termination.
elsif Kind = N_If_Statement
and then Present (Else_Statements (Last_Stm))
then
Check_Statement_Sequence (Then_Statements (Last_Stm));
Check_Statement_Sequence (Else_Statements (Last_Stm));
if Present (Elsif_Parts (Last_Stm)) then
declare
Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
begin
while Present (Elsif_Part) loop
Check_Statement_Sequence (Then_Statements (Elsif_Part));
Next (Elsif_Part);
end loop;
end;
end if;
return;
-- Case statement, check each case for proper termination
elsif Kind = N_Case_Statement then
declare
Case_Alt : Node_Id;
begin
Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
while Present (Case_Alt) loop
Check_Statement_Sequence (Statements (Case_Alt));
Next_Non_Pragma (Case_Alt);
end loop;
end;
return;
-- Block statement, check its handled sequence of statements
elsif Kind = N_Block_Statement then
declare
Err1 : Boolean;
begin
Check_Returns
(Handled_Statement_Sequence (Last_Stm), Mode, Err1);
if Err1 then
Err := True;
end if;
return;
end;
-- Loop statement. If there is an iteration scheme, we can definitely
-- fall out of the loop. Similarly if there is an exit statement, we
-- can fall out. In either case we need a following return.
elsif Kind = N_Loop_Statement then
if Present (Iteration_Scheme (Last_Stm))
or else Has_Exit (Entity (Identifier (Last_Stm)))
then
null;
-- A loop with no exit statement or iteration scheme is either
-- an infinite loop, or it has some other exit (raise/return).
-- In either case, no warning is required.
else
return;
end if;
-- Timed entry call, check entry call and delay alternatives
-- Note: in expanded code, the timed entry call has been converted
-- to a set of expanded statements on which the check will work
-- correctly in any case.
elsif Kind = N_Timed_Entry_Call then
declare
ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
DCA : constant Node_Id := Delay_Alternative (Last_Stm);
begin
-- If statement sequence of entry call alternative is missing,
-- then we can definitely fall through, and we post the error
-- message on the entry call alternative itself.
if No (Statements (ECA)) then
Last_Stm := ECA;
-- If statement sequence of delay alternative is missing, then
-- we can definitely fall through, and we post the error
-- message on the delay alternative itself.
-- Note: if both ECA and DCA are missing the return, then we
-- post only one message, should be enough to fix the bugs.
-- If not we will get a message next time on the DCA when the
-- ECA is fixed.
elsif No (Statements (DCA)) then
Last_Stm := DCA;
-- Else check both statement sequences
else
Check_Statement_Sequence (Statements (ECA));
Check_Statement_Sequence (Statements (DCA));
return;
end if;
end;
-- Conditional entry call, check entry call and else part
-- Note: in expanded code, the conditional entry call has been
-- converted to a set of expanded statements on which the check
-- will work correctly in any case.
elsif Kind = N_Conditional_Entry_Call then
declare
ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
begin
-- If statement sequence of entry call alternative is missing,
-- then we can definitely fall through, and we post the error
-- message on the entry call alternative itself.
if No (Statements (ECA)) then
Last_Stm := ECA;
-- Else check statement sequence and else part
else
Check_Statement_Sequence (Statements (ECA));
Check_Statement_Sequence (Else_Statements (Last_Stm));
return;
end if;
end;
end if;
-- If we fall through, issue appropriate message
if Mode = 'F' then
-- Kill warning if last statement is a raise exception call,
-- or a pragma Assert (False). Note that with assertions enabled,
-- such a pragma has been converted into a raise exception call
-- already, so the Assert_False is for the assertions off case.
if not Raise_Exception_Call and then not Assert_False then
-- In GNATprove mode, it is an error to have a missing return
Error_Msg_Warn := SPARK_Mode /= On;
-- Issue error message or warning
Error_Msg_N
("RETURN statement missing following this statement<<!",
Last_Stm);
Error_Msg_N
("\Program_Error [<<!", Last_Stm);
end if;
-- Note: we set Err even though we have not issued a warning
-- because we still have a case of a missing return. This is
-- an extremely marginal case, probably will never be noticed
-- but we might as well get it right.
Err := True;
-- Otherwise we have the case of a procedure marked No_Return
else
if not Raise_Exception_Call then
if GNATprove_Mode then
Error_Msg_N
("implied return after this statement would have raised "
& "Program_Error", Last_Stm);
-- In normal compilation mode, do not warn on a generated call
-- (e.g. in the body of a renaming as completion).
elsif Comes_From_Source (Last_Stm) then
Error_Msg_N
("implied return after this statement will raise "
& "Program_Error??", Last_Stm);
end if;
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_NE
("\procedure & is marked as No_Return<<!", Last_Stm, Proc);
end if;
declare
RE : constant Node_Id :=
Make_Raise_Program_Error (Sloc (Last_Stm),
Reason => PE_Implicit_Return);
begin
Insert_After (Last_Stm, RE);
Analyze (RE);
end;
end if;
end Check_Statement_Sequence;
-- Start of processing for Check_Returns
begin
Err := False;
Check_Statement_Sequence (Statements (HSS));
if Present (Exception_Handlers (HSS)) then
Handler := First_Non_Pragma (Exception_Handlers (HSS));
while Present (Handler) loop
Check_Statement_Sequence (Statements (Handler));
Next_Non_Pragma (Handler);
end loop;
end if;
end Check_Returns;
----------------------------
-- Check_Subprogram_Order --
----------------------------
procedure Check_Subprogram_Order (N : Node_Id) is
function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
-- This is used to check if S1 > S2 in the sense required by this test,
-- for example nameab < namec, but name2 < name10.
-----------------------------
-- Subprogram_Name_Greater --
-----------------------------
function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
L1, L2 : Positive;
N1, N2 : Natural;
begin
-- Deal with special case where names are identical except for a
-- numerical suffix. These are handled specially, taking the numeric
-- ordering from the suffix into account.
L1 := S1'Last;
while S1 (L1) in '0' .. '9' loop
L1 := L1 - 1;
end loop;
L2 := S2'Last;
while S2 (L2) in '0' .. '9' loop
L2 := L2 - 1;
end loop;
-- If non-numeric parts non-equal, do straight compare
if S1 (S1'First .. L1) /= S2 (S2'First .. L2) then
return S1 > S2;
-- If non-numeric parts equal, compare suffixed numeric parts. Note
-- that a missing suffix is treated as numeric zero in this test.
else
N1 := 0;
while L1 < S1'Last loop
L1 := L1 + 1;
N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
end loop;
N2 := 0;
while L2 < S2'Last loop
L2 := L2 + 1;
N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
end loop;
return N1 > N2;
end if;
end Subprogram_Name_Greater;
-- Start of processing for Check_Subprogram_Order
begin
-- Check body in alpha order if this is option
if Style_Check
and then Style_Check_Order_Subprograms
and then Nkind (N) = N_Subprogram_Body
and then Comes_From_Source (N)
and then In_Extended_Main_Source_Unit (N)
then
declare
LSN : String_Ptr
renames Scope_Stack.Table
(Scope_Stack.Last).Last_Subprogram_Name;
Body_Id : constant Entity_Id :=
Defining_Entity (Specification (N));
begin
Get_Decoded_Name_String (Chars (Body_Id));
if LSN /= null then
if Subprogram_Name_Greater
(LSN.all, Name_Buffer (1 .. Name_Len))
then
Style.Subprogram_Not_In_Alpha_Order (Body_Id);
end if;
Free (LSN);
end if;
LSN := new String'(Name_Buffer (1 .. Name_Len));
end;
end if;
end Check_Subprogram_Order;
------------------------------
-- Check_Subtype_Conformant --
------------------------------
procedure Check_Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Skip_Controlling_Formals : Boolean := False;
Get_Inst : Boolean := False)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc,
Skip_Controlling_Formals => Skip_Controlling_Formals,
Get_Inst => Get_Inst);
end Check_Subtype_Conformant;
-----------------------------------
-- Check_Synchronized_Overriding --
-----------------------------------
procedure Check_Synchronized_Overriding
(Def_Id : Entity_Id;
Overridden_Subp : out Entity_Id)
is
Ifaces_List : Elist_Id;
In_Scope : Boolean;
Typ : Entity_Id;
function Is_Valid_Formal (F : Entity_Id) return Boolean;
-- Predicate for legality rule in 9.4 (11.9/2): If an inherited
-- subprogram is implemented by a protected procedure or entry,
-- its first parameter must be out, in out, or access-to-variable.
function Matches_Prefixed_View_Profile
(Prim_Params : List_Id;
Iface_Params : List_Id) return Boolean;
-- Determine whether a subprogram's parameter profile Prim_Params
-- matches that of a potentially overridden interface subprogram
-- Iface_Params. Also determine if the type of first parameter of
-- Iface_Params is an implemented interface.
----------------------
-- Is_Valid_Formal --
----------------------
function Is_Valid_Formal (F : Entity_Id) return Boolean is
begin
return
Ekind (F) in E_In_Out_Parameter | E_Out_Parameter
or else
(Nkind (Parameter_Type (Parent (F))) = N_Access_Definition
and then not Constant_Present (Parameter_Type (Parent (F))));
end Is_Valid_Formal;
-----------------------------------
-- Matches_Prefixed_View_Profile --
-----------------------------------
function Matches_Prefixed_View_Profile
(Prim_Params : List_Id;
Iface_Params : List_Id) return Boolean
is
function Is_Implemented
(Ifaces_List : Elist_Id;
Iface : Entity_Id) return Boolean;
-- Determine if Iface is implemented by the current task or
-- protected type.
--------------------
-- Is_Implemented --
--------------------
function Is_Implemented
(Ifaces_List : Elist_Id;
Iface : Entity_Id) return Boolean
is
Iface_Elmt : Elmt_Id;
begin
Iface_Elmt := First_Elmt (Ifaces_List);
while Present (Iface_Elmt) loop
if Node (Iface_Elmt) = Iface then
return True;
end if;
Next_Elmt (Iface_Elmt);
end loop;
return False;
end Is_Implemented;
-- Local variables
Iface_Id : Entity_Id;
Iface_Param : Node_Id;
Iface_Typ : Entity_Id;
Prim_Id : Entity_Id;
Prim_Param : Node_Id;
Prim_Typ : Entity_Id;
-- Start of processing for Matches_Prefixed_View_Profile
begin
Iface_Param := First (Iface_Params);
Iface_Typ := Etype (Defining_Identifier (Iface_Param));
if Is_Access_Type (Iface_Typ) then
Iface_Typ := Designated_Type (Iface_Typ);
end if;
Prim_Param := First (Prim_Params);
-- The first parameter of the potentially overridden subprogram must
-- be an interface implemented by Prim.
if not Is_Interface (Iface_Typ)
or else not Is_Implemented (Ifaces_List, Iface_Typ)
then
return False;
end if;
-- The checks on the object parameters are done, so move on to the
-- rest of the parameters.
if not In_Scope then
Next (Prim_Param);
end if;
Next (Iface_Param);
while Present (Iface_Param) and then Present (Prim_Param) loop
Iface_Id := Defining_Identifier (Iface_Param);
Iface_Typ := Find_Parameter_Type (Iface_Param);
Prim_Id := Defining_Identifier (Prim_Param);
Prim_Typ := Find_Parameter_Type (Prim_Param);
if Ekind (Iface_Typ) = E_Anonymous_Access_Type
and then Ekind (Prim_Typ) = E_Anonymous_Access_Type
and then Is_Concurrent_Type (Designated_Type (Prim_Typ))
then
Iface_Typ := Designated_Type (Iface_Typ);
Prim_Typ := Designated_Type (Prim_Typ);
end if;
-- Case of multiple interface types inside a parameter profile
-- (Obj_Param : in out Iface; ...; Param : Iface)
-- If the interface type is implemented, then the matching type in
-- the primitive should be the implementing record type.
if Ekind (Iface_Typ) = E_Record_Type
and then Is_Interface (Iface_Typ)
and then Is_Implemented (Ifaces_List, Iface_Typ)
then
if Prim_Typ /= Typ then
return False;
end if;
-- The two parameters must be both mode and subtype conformant
elsif Ekind (Iface_Id) /= Ekind (Prim_Id)
or else not
Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant)
then
return False;
end if;
Next (Iface_Param);
Next (Prim_Param);
end loop;
-- One of the two lists contains more parameters than the other
if Present (Iface_Param) or else Present (Prim_Param) then
return False;
end if;
return True;
end Matches_Prefixed_View_Profile;
-- Start of processing for Check_Synchronized_Overriding
begin
Overridden_Subp := Empty;
-- Def_Id must be an entry or a subprogram. We should skip predefined
-- primitives internally generated by the front end; however at this
-- stage predefined primitives are still not fully decorated. As a
-- minor optimization we skip here internally generated subprograms.
if (Ekind (Def_Id) /= E_Entry
and then Ekind (Def_Id) /= E_Function
and then Ekind (Def_Id) /= E_Procedure)
or else not Comes_From_Source (Def_Id)
then
return;
end if;
-- Search for the concurrent declaration since it contains the list of
-- all implemented interfaces. In this case, the subprogram is declared
-- within the scope of a protected or a task type.
if Present (Scope (Def_Id))
and then Is_Concurrent_Type (Scope (Def_Id))
and then not Is_Generic_Actual_Type (Scope (Def_Id))
then
Typ := Scope (Def_Id);
In_Scope := True;
-- The enclosing scope is not a synchronized type and the subprogram
-- has no formals.
elsif No (First_Formal (Def_Id)) then
return;
-- The subprogram has formals and hence it may be a primitive of a
-- concurrent type.
else
Typ := Etype (First_Formal (Def_Id));
if Is_Access_Type (Typ) then
Typ := Directly_Designated_Type (Typ);
end if;
if Is_Concurrent_Type (Typ)
and then not Is_Generic_Actual_Type (Typ)
then
In_Scope := False;
-- This case occurs when the concurrent type is declared within a
-- generic unit. As a result the corresponding record has been built
-- and used as the type of the first formal, we just have to retrieve
-- the corresponding concurrent type.
elsif Is_Concurrent_Record_Type (Typ)
and then not Is_Class_Wide_Type (Typ)
and then Present (Corresponding_Concurrent_Type (Typ))
then
Typ := Corresponding_Concurrent_Type (Typ);
In_Scope := False;
else
return;
end if;
end if;
-- There is no overriding to check if this is an inherited operation in
-- a type derivation for a generic actual.
Collect_Interfaces (Typ, Ifaces_List);
if Is_Empty_Elmt_List (Ifaces_List) then
return;
end if;
-- Determine whether entry or subprogram Def_Id overrides a primitive
-- operation that belongs to one of the interfaces in Ifaces_List.
declare
Candidate : Entity_Id := Empty;
Hom : Entity_Id := Empty;
Subp : Entity_Id := Empty;
begin
-- Traverse the homonym chain, looking for a potentially overridden
-- subprogram that belongs to an implemented interface.
Hom := Current_Entity_In_Scope (Def_Id);
while Present (Hom) loop
Subp := Hom;
if Subp = Def_Id
or else not Is_Overloadable (Subp)
or else not Is_Primitive (Subp)
or else not Is_Dispatching_Operation (Subp)
or else not Present (Find_Dispatching_Type (Subp))
or else not Is_Interface (Find_Dispatching_Type (Subp))
then
null;
-- Entries and procedures can override abstract or null interface
-- procedures.
elsif Ekind (Def_Id) in E_Entry | E_Procedure
and then Ekind (Subp) = E_Procedure
and then Matches_Prefixed_View_Profile
(Parameter_Specifications (Parent (Def_Id)),
Parameter_Specifications (Parent (Subp)))
then
Candidate := Subp;
-- For an overridden subprogram Subp, check whether the mode
-- of its first parameter is correct depending on the kind of
-- synchronized type.
declare
Formal : constant Node_Id := First_Formal (Candidate);
begin
-- In order for an entry or a protected procedure to
-- override, the first parameter of the overridden routine
-- must be of mode "out", "in out", or access-to-variable.
if Ekind (Candidate) in E_Entry | E_Procedure
and then Is_Protected_Type (Typ)
and then not Is_Valid_Formal (Formal)
then
null;
-- All other cases are OK since a task entry or routine does
-- not have a restriction on the mode of the first parameter
-- of the overridden interface routine.
else
Overridden_Subp := Candidate;
return;
end if;
end;
-- Functions can override abstract interface functions. Return
-- types must be subtype conformant.
elsif Ekind (Def_Id) = E_Function
and then Ekind (Subp) = E_Function
and then Matches_Prefixed_View_Profile
(Parameter_Specifications (Parent (Def_Id)),
Parameter_Specifications (Parent (Subp)))
and then Conforming_Types
(Etype (Def_Id), Etype (Subp), Subtype_Conformant)
then
Candidate := Subp;
-- If an inherited subprogram is implemented by a protected
-- function, then the first parameter of the inherited
-- subprogram shall be of mode in, but not an access-to-
-- variable parameter (RM 9.4(11/9)).
if Present (First_Formal (Subp))
and then Ekind (First_Formal (Subp)) = E_In_Parameter
and then
(not Is_Access_Type (Etype (First_Formal (Subp)))
or else
Is_Access_Constant (Etype (First_Formal (Subp))))
then
Overridden_Subp := Subp;
return;
end if;
end if;
Hom := Homonym (Hom);
end loop;
-- After examining all candidates for overriding, we are left with
-- the best match, which is a mode-incompatible interface routine.
if In_Scope and then Present (Candidate) then
Error_Msg_PT (Def_Id, Candidate);
end if;
Overridden_Subp := Candidate;
return;
end;
end Check_Synchronized_Overriding;
---------------------------
-- Check_Type_Conformant --
---------------------------
procedure Check_Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
end Check_Type_Conformant;
---------------------------
-- Can_Override_Operator --
---------------------------
function Can_Override_Operator (Subp : Entity_Id) return Boolean is
Typ : Entity_Id;
begin
-- Return False if not an operator. We test the name rather than testing
-- that the Nkind is N_Defining_Operator_Symbol, because there are cases
-- where an operator entity can be an N_Defining_Identifier (such as for
-- function instantiations).
if Chars (Subp) not in Any_Operator_Name then
return False;
else
Typ := Base_Type (Etype (First_Formal (Subp)));
-- Check explicitly that the operation is a primitive of the type
return Operator_Matches_Spec (Subp, Subp)
and then not Is_Generic_Type (Typ)
and then Scope (Subp) = Scope (Typ)
and then not Is_Class_Wide_Type (Typ);
end if;
end Can_Override_Operator;
----------------------
-- Conforming_Types --
----------------------
function Conforming_Types
(T1 : Entity_Id;
T2 : Entity_Id;
Ctype : Conformance_Type;
Get_Inst : Boolean := False) return Boolean
is
function Base_Types_Match
(Typ_1 : Entity_Id;
Typ_2 : Entity_Id) return Boolean;
-- If neither Typ_1 nor Typ_2 are generic actual types, or if they are
-- in different scopes (e.g. parent and child instances), then verify
-- that the base types are equal. Otherwise Typ_1 and Typ_2 must be on
-- the same subtype chain. The whole purpose of this procedure is to
-- prevent spurious ambiguities in an instantiation that may arise if
-- two distinct generic types are instantiated with the same actual.
function Find_Designated_Type (Typ : Entity_Id) return Entity_Id;
-- An access parameter can designate an incomplete type. If the
-- incomplete type is the limited view of a type from a limited_
-- with_clause, check whether the non-limited view is available.
-- If it is a (non-limited) incomplete type, get the full view.
function Matches_Limited_With_View
(Typ_1 : Entity_Id;
Typ_2 : Entity_Id) return Boolean;
-- Returns True if and only if either Typ_1 denotes a limited view of
-- Typ_2 or Typ_2 denotes a limited view of Typ_1. This can arise when
-- the limited with view of a type is used in a subprogram declaration
-- and the subprogram body is in the scope of a regular with clause for
-- the same unit. In such a case, the two type entities are considered
-- identical for purposes of conformance checking.
----------------------
-- Base_Types_Match --
----------------------
function Base_Types_Match
(Typ_1 : Entity_Id;
Typ_2 : Entity_Id) return Boolean
is
Base_1 : constant Entity_Id := Base_Type (Typ_1);
Base_2 : constant Entity_Id := Base_Type (Typ_2);
begin
if Typ_1 = Typ_2 then
return True;
elsif Base_1 = Base_2 then
-- The following is too permissive. A more precise test should
-- check that the generic actual is an ancestor subtype of the
-- other ???.
-- See code in Find_Corresponding_Spec that applies an additional
-- filter to handle accidental amiguities in instances.
return
not Is_Generic_Actual_Type (Typ_1)
or else not Is_Generic_Actual_Type (Typ_2)
or else Scope (Typ_1) /= Scope (Typ_2);
-- If Typ_2 is a generic actual type it is declared as the subtype of
-- the actual. If that actual is itself a subtype we need to use its
-- own base type to check for compatibility.
elsif Ekind (Base_2) = Ekind (Typ_2)
and then Base_1 = Base_Type (Base_2)
then
return True;
elsif Ekind (Base_1) = Ekind (Typ_1)
and then Base_2 = Base_Type (Base_1)
then
return True;
else
return False;
end if;
end Base_Types_Match;
--------------------------
-- Find_Designated_Type --
--------------------------
function Find_Designated_Type (Typ : Entity_Id) return Entity_Id is
Desig : Entity_Id;
begin
Desig := Directly_Designated_Type (Typ);
if Ekind (Desig) = E_Incomplete_Type then
-- If regular incomplete type, get full view if available
if Present (Full_View (Desig)) then
Desig := Full_View (Desig);
-- If limited view of a type, get non-limited view if available,
-- and check again for a regular incomplete type.
elsif Present (Non_Limited_View (Desig)) then
Desig := Get_Full_View (Non_Limited_View (Desig));
end if;
end if;
return Desig;
end Find_Designated_Type;
-------------------------------
-- Matches_Limited_With_View --
-------------------------------
function Matches_Limited_With_View
(Typ_1 : Entity_Id;
Typ_2 : Entity_Id) return Boolean
is
function Is_Matching_Limited_View
(Typ : Entity_Id;
View : Entity_Id) return Boolean;
-- Determine whether non-limited view View denotes type Typ in some
-- conformant fashion.
------------------------------
-- Is_Matching_Limited_View --
------------------------------
function Is_Matching_Limited_View
(Typ : Entity_Id;
View : Entity_Id) return Boolean
is
Root_Typ : Entity_Id;
Root_View : Entity_Id;
begin
-- The non-limited view directly denotes the type
if Typ = View then
return True;
-- The type is a subtype of the non-limited view
elsif Is_Subtype_Of (Typ, View) then
return True;
-- Both the non-limited view and the type denote class-wide types
elsif Is_Class_Wide_Type (Typ)
and then Is_Class_Wide_Type (View)
then
Root_Typ := Root_Type (Typ);
Root_View := Root_Type (View);
if Root_Typ = Root_View then
return True;
-- An incomplete tagged type and its full view may receive two
-- distinct class-wide types when the related package has not
-- been analyzed yet.
-- package Pack is
-- type T is tagged; -- CW_1
-- type T is tagged null record; -- CW_2
-- end Pack;
-- This is because the package lacks any semantic information
-- that may eventually link both views of T. As a consequence,
-- a client of the limited view of Pack will see CW_2 while a
-- client of the non-limited view of Pack will see CW_1.
elsif Is_Incomplete_Type (Root_Typ)
and then Present (Full_View (Root_Typ))
and then Full_View (Root_Typ) = Root_View
then
return True;
elsif Is_Incomplete_Type (Root_View)
and then Present (Full_View (Root_View))
and then Full_View (Root_View) = Root_Typ
then
return True;
end if;
end if;
return False;
end Is_Matching_Limited_View;
-- Start of processing for Matches_Limited_With_View
begin
-- In some cases a type imported through a limited_with clause, and
-- its non-limited view are both visible, for example in an anonymous
-- access-to-class-wide type in a formal, or when building the body
-- for a subprogram renaming after the subprogram has been frozen.
-- In these cases both entities designate the same type. In addition,
-- if one of them is an actual in an instance, it may be a subtype of
-- the non-limited view of the other.
if From_Limited_With (Typ_1)
and then From_Limited_With (Typ_2)
and then Available_View (Typ_1) = Available_View (Typ_2)
then
return True;
elsif From_Limited_With (Typ_1) then
return Is_Matching_Limited_View (Typ_2, Available_View (Typ_1));
elsif From_Limited_With (Typ_2) then
return Is_Matching_Limited_View (Typ_1, Available_View (Typ_2));
else
return False;
end if;
end Matches_Limited_With_View;
-- Local variables
Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
Type_1 : Entity_Id := T1;
Type_2 : Entity_Id := T2;
-- Start of processing for Conforming_Types
begin
-- The context is an instance association for a formal access-to-
-- subprogram type; the formal parameter types require mapping because
-- they may denote other formal parameters of the generic unit.
if Get_Inst then
Type_1 := Get_Instance_Of (T1);
Type_2 := Get_Instance_Of (T2);
end if;
-- If one of the types is a view of the other introduced by a limited
-- with clause, treat these as conforming for all purposes.
if Matches_Limited_With_View (T1, T2) then
return True;
elsif Base_Types_Match (Type_1, Type_2) then
if Ctype <= Mode_Conformant then
return True;
else
return
Subtypes_Statically_Match (Type_1, Type_2)
and then Dimensions_Match (Type_1, Type_2);
end if;
elsif Is_Incomplete_Or_Private_Type (Type_1)
and then Present (Full_View (Type_1))
and then Base_Types_Match (Full_View (Type_1), Type_2)
then
return
Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
elsif Ekind (Type_2) = E_Incomplete_Type
and then Present (Full_View (Type_2))
and then Base_Types_Match (Type_1, Full_View (Type_2))
then
return
Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
elsif Is_Private_Type (Type_2)
and then In_Instance
and then Present (Full_View (Type_2))
and then Base_Types_Match (Type_1, Full_View (Type_2))
then
return
Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
-- Another confusion between views in a nested instance with an
-- actual private type whose full view is not in scope.
elsif Ekind (Type_2) = E_Private_Subtype
and then In_Instance
and then Etype (Type_2) = Type_1
then
return True;
-- In Ada 2012, incomplete types (including limited views) can appear
-- as actuals in instantiations, where they are conformant to the
-- corresponding incomplete formal.
elsif Is_Incomplete_Type (Type_1)
and then Is_Incomplete_Type (Type_2)
and then In_Instance
and then (Used_As_Generic_Actual (Type_1)
or else Used_As_Generic_Actual (Type_2))
then
return True;
end if;
-- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be
-- treated recursively because they carry a signature. As far as
-- conformance is concerned, convention plays no role, and either
-- or both could be access to protected subprograms.
Are_Anonymous_Access_To_Subprogram_Types :=
Ekind (Type_1) in E_Anonymous_Access_Subprogram_Type
| E_Anonymous_Access_Protected_Subprogram_Type
and then
Ekind (Type_2) in E_Anonymous_Access_Subprogram_Type
| E_Anonymous_Access_Protected_Subprogram_Type;
-- Test anonymous access type case. For this case, static subtype
-- matching is required for mode conformance (RM 6.3.1(15)). We check
-- the base types because we may have built internal subtype entities
-- to handle null-excluding types (see Process_Formals).
if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type
and then
Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type)
-- Ada 2005 (AI-254)
or else Are_Anonymous_Access_To_Subprogram_Types
then
declare
Desig_1 : Entity_Id;
Desig_2 : Entity_Id;
begin
-- In Ada 2005, access constant indicators must match for
-- subtype conformance.
if Ada_Version >= Ada_2005
and then Ctype >= Subtype_Conformant
and then
Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2)
then
return False;
end if;
Desig_1 := Find_Designated_Type (Type_1);
Desig_2 := Find_Designated_Type (Type_2);
-- If the context is an instance association for a formal
-- access-to-subprogram type; formal access parameter designated
-- types require mapping because they may denote other formal
-- parameters of the generic unit.
if Get_Inst then
Desig_1 := Get_Instance_Of (Desig_1);
Desig_2 := Get_Instance_Of (Desig_2);
end if;
-- It is possible for a Class_Wide_Type to be introduced for an
-- incomplete type, in which case there is a separate class_ wide
-- type for the full view. The types conform if their Etypes
-- conform, i.e. one may be the full view of the other. This can
-- only happen in the context of an access parameter, other uses
-- of an incomplete Class_Wide_Type are illegal.
if Is_Class_Wide_Type (Desig_1)
and then
Is_Class_Wide_Type (Desig_2)
then
return
Conforming_Types
(Etype (Base_Type (Desig_1)),
Etype (Base_Type (Desig_2)), Ctype);
elsif Are_Anonymous_Access_To_Subprogram_Types then
if Ada_Version < Ada_2005 then
return
Ctype = Type_Conformant
or else Subtypes_Statically_Match (Desig_1, Desig_2);
-- We must check the conformance of the signatures themselves
else
declare
Conformant : Boolean;
begin
Check_Conformance
(Desig_1, Desig_2, Ctype, False, Conformant);
return Conformant;
end;
end if;
-- A limited view of an actual matches the corresponding
-- incomplete formal.
elsif Ekind (Desig_2) = E_Incomplete_Subtype
and then From_Limited_With (Desig_2)
and then Used_As_Generic_Actual (Etype (Desig_2))
then
return True;
else
return Base_Type (Desig_1) = Base_Type (Desig_2)
and then (Ctype = Type_Conformant
or else
Subtypes_Statically_Match (Desig_1, Desig_2));
end if;
end;
-- Otherwise definitely no match
else
if ((Ekind (Type_1) = E_Anonymous_Access_Type
and then Is_Access_Type (Type_2))
or else (Ekind (Type_2) = E_Anonymous_Access_Type
and then Is_Access_Type (Type_1)))
and then
Conforming_Types
(Designated_Type (Type_1), Designated_Type (Type_2), Ctype)
then
May_Hide_Profile := True;
end if;
return False;
end if;
end Conforming_Types;
--------------------------
-- Create_Extra_Formals --
--------------------------
procedure Create_Extra_Formals (E : Entity_Id) is
First_Extra : Entity_Id := Empty;
Formal : Entity_Id;
Last_Extra : Entity_Id := Empty;
function Add_Extra_Formal
(Assoc_Entity : Entity_Id;
Typ : Entity_Id;
Scope : Entity_Id;
Suffix : String) return Entity_Id;
-- Add an extra formal to the current list of formals and extra formals.
-- The extra formal is added to the end of the list of extra formals,
-- and also returned as the result. These formals are always of mode IN.
-- The new formal has the type Typ, is declared in Scope, and its name
-- is given by a concatenation of the name of Assoc_Entity and Suffix.
-- The following suffixes are currently used. They should not be changed
-- without coordinating with CodePeer, which makes use of these to
-- provide better messages.
-- O denotes the Constrained bit.
-- L denotes the accessibility level.
-- BIP_xxx denotes an extra formal for a build-in-place function. See
-- the full list in exp_ch6.BIP_Formal_Kind.
----------------------
-- Add_Extra_Formal --
----------------------
function Add_Extra_Formal
(Assoc_Entity : Entity_Id;
Typ : Entity_Id;
Scope : Entity_Id;
Suffix : String) return Entity_Id
is
EF : constant Entity_Id :=
Make_Defining_Identifier (Sloc (Assoc_Entity),
Chars => New_External_Name (Chars (Assoc_Entity),
Suffix => Suffix));
begin
-- A little optimization. Never generate an extra formal for the
-- _init operand of an initialization procedure, since it could
-- never be used.
if Chars (Formal) = Name_uInit then
return Empty;
end if;
Mutate_Ekind (EF, E_In_Parameter);
Set_Actual_Subtype (EF, Typ);
Set_Etype (EF, Typ);
Set_Scope (EF, Scope);
Set_Mechanism (EF, Default_Mechanism);
Set_Formal_Validity (EF);
if No (First_Extra) then
First_Extra := EF;
Set_Extra_Formals (Scope, EF);
end if;
if Present (Last_Extra) then
Set_Extra_Formal (Last_Extra, EF);
end if;
Last_Extra := EF;
return EF;
end Add_Extra_Formal;
-- Local variables
Formal_Type : Entity_Id;
P_Formal : Entity_Id := Empty;
-- Start of processing for Create_Extra_Formals
begin
-- We never generate extra formals if expansion is not active because we
-- don't need them unless we are generating code.
if not Expander_Active then
return;
end if;
-- No need to generate extra formals in interface thunks whose target
-- primitive has no extra formals.
if Is_Thunk (E) and then No (Extra_Formals (Thunk_Entity (E))) then
return;
end if;
-- If this is a derived subprogram then the subtypes of the parent
-- subprogram's formal parameters will be used to determine the need
-- for extra formals.
if Is_Overloadable (E) and then Present (Alias (E)) then
P_Formal := First_Formal (Alias (E));
end if;
Formal := First_Formal (E);
while Present (Formal) loop
Last_Extra := Formal;
Next_Formal (Formal);
end loop;
-- If Extra_Formals were already created, don't do it again. This
-- situation may arise for subprogram types created as part of
-- dispatching calls (see Expand_Dispatching_Call).
if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then
return;
end if;
-- If the subprogram is a predefined dispatching subprogram then don't
-- generate any extra constrained or accessibility level formals. In
-- general we suppress these for internal subprograms (by not calling
-- Freeze_Subprogram and Create_Extra_Formals at all), but internally
-- generated stream attributes do get passed through because extra
-- build-in-place formals are needed in some cases (limited 'Input).
if Is_Predefined_Internal_Operation (E) then
goto Test_For_Func_Result_Extras;
end if;
Formal := First_Formal (E);
while Present (Formal) loop
-- Create extra formal for supporting the attribute 'Constrained.
-- The case of a private type view without discriminants also
-- requires the extra formal if the underlying type has defaulted
-- discriminants.
if Ekind (Formal) /= E_In_Parameter then
if Present (P_Formal) then
Formal_Type := Etype (P_Formal);
else
Formal_Type := Etype (Formal);
end if;
-- Do not produce extra formals for Unchecked_Union parameters.
-- Jump directly to the end of the loop.
if Is_Unchecked_Union (Base_Type (Formal_Type)) then
goto Skip_Extra_Formal_Generation;
end if;
if not Has_Discriminants (Formal_Type)
and then Is_Private_Type (Formal_Type)
and then Present (Underlying_Type (Formal_Type))
then
Formal_Type := Underlying_Type (Formal_Type);
end if;
-- Suppress the extra formal if formal's subtype is constrained or
-- indefinite, or we're compiling for Ada 2012 and the underlying
-- type is tagged and limited. In Ada 2012, a limited tagged type
-- can have defaulted discriminants, but 'Constrained is required
-- to return True, so the formal is never needed (see AI05-0214).
-- Note that this ensures consistency of calling sequences for
-- dispatching operations when some types in a class have defaults
-- on discriminants and others do not (and requiring the extra
-- formal would introduce distributed overhead).
-- If the type does not have a completion yet, treat as prior to
-- Ada 2012 for consistency.
if Has_Discriminants (Formal_Type)
and then not Is_Constrained (Formal_Type)
and then Is_Definite_Subtype (Formal_Type)
and then (Ada_Version < Ada_2012
or else No (Underlying_Type (Formal_Type))
or else not
(Is_Limited_Type (Formal_Type)
and then
(Is_Tagged_Type
(Underlying_Type (Formal_Type)))))
then
Set_Extra_Constrained
(Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O"));
end if;
end if;
-- Create extra formal for supporting accessibility checking. This
-- is done for both anonymous access formals and formals of named
-- access types that are marked as controlling formals. The latter
-- case can occur when Expand_Dispatching_Call creates a subprogram
-- type and substitutes the types of access-to-class-wide actuals
-- for the anonymous access-to-specific-type of controlling formals.
-- Base_Type is applied because in cases where there is a null
-- exclusion the formal may have an access subtype.
-- This is suppressed if we specifically suppress accessibility
-- checks at the package level for either the subprogram, or the
-- package in which it resides. However, we do not suppress it
-- simply if the scope has accessibility checks suppressed, since
-- this could cause trouble when clients are compiled with a
-- different suppression setting. The explicit checks at the
-- package level are safe from this point of view.
if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type
or else (Is_Controlling_Formal (Formal)
and then Is_Access_Type (Base_Type (Etype (Formal)))))
and then not
(Explicit_Suppress (E, Accessibility_Check)
or else
Explicit_Suppress (Scope (E), Accessibility_Check))
and then
(No (P_Formal)
or else Present (Extra_Accessibility (P_Formal)))
then
Set_Extra_Accessibility
(Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L"));
end if;
-- This label is required when skipping extra formal generation for
-- Unchecked_Union parameters.
<<Skip_Extra_Formal_Generation>>
if Present (P_Formal) then
Next_Formal (P_Formal);
end if;
Next_Formal (Formal);
end loop;
<<Test_For_Func_Result_Extras>>
-- Ada 2012 (AI05-234): "the accessibility level of the result of a
-- function call is ... determined by the point of call ...".
if Needs_Result_Accessibility_Level (E) then
Set_Extra_Accessibility_Of_Result
(E, Add_Extra_Formal (E, Standard_Natural, E, "L"));
end if;
-- Ada 2005 (AI-318-02): In the case of build-in-place functions, add
-- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind.
if Is_Build_In_Place_Function (E) then
declare
Result_Subt : constant Entity_Id := Etype (E);
Formal_Typ : Entity_Id;
Subp_Decl : Node_Id;
Discard : Entity_Id;
begin
-- In the case of functions with unconstrained result subtypes,
-- add a 4-state formal indicating whether the return object is
-- allocated by the caller (1), or should be allocated by the
-- callee on the secondary stack (2), in the global heap (3), or
-- in a user-defined storage pool (4). For the moment we just use
-- Natural for the type of this formal. Note that this formal
-- isn't usually needed in the case where the result subtype is
-- constrained, but it is needed when the function has a tagged
-- result, because generally such functions can be called in a
-- dispatching context and such calls must be handled like calls
-- to a class-wide function.
if Needs_BIP_Alloc_Form (E) then
Discard :=
Add_Extra_Formal
(E, Standard_Natural,
E, BIP_Formal_Suffix (BIP_Alloc_Form));
-- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to
-- use a user-defined pool. This formal is not added on
-- ZFP as those targets do not support pools.
if RTE_Available (RE_Root_Storage_Pool_Ptr) then
Discard :=
Add_Extra_Formal
(E, RTE (RE_Root_Storage_Pool_Ptr),
E, BIP_Formal_Suffix (BIP_Storage_Pool));
end if;
end if;
-- In the case of functions whose result type needs finalization,
-- add an extra formal which represents the finalization master.
if Needs_BIP_Finalization_Master (E) then
Discard :=
Add_Extra_Formal
(E, RTE (RE_Finalization_Master_Ptr),
E, BIP_Formal_Suffix (BIP_Finalization_Master));
end if;
-- When the result type contains tasks, add two extra formals: the
-- master of the tasks to be created, and the caller's activation
-- chain.
if Needs_BIP_Task_Actuals (E) then
Discard :=
Add_Extra_Formal
(E, Standard_Integer,
E, BIP_Formal_Suffix (BIP_Task_Master));
Set_Has_Master_Entity (E);
Discard :=
Add_Extra_Formal
(E, RTE (RE_Activation_Chain_Access),
E, BIP_Formal_Suffix (BIP_Activation_Chain));
end if;
-- All build-in-place functions get an extra formal that will be
-- passed the address of the return object within the caller.
Formal_Typ :=
Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E));
-- Incomplete_View_From_Limited_With is needed here because
-- gigi gets confused if the designated type is the full view
-- coming from a limited-with'ed package. In the normal case,
-- (no limited with) Incomplete_View_From_Limited_With
-- returns Result_Subt.
Set_Directly_Designated_Type
(Formal_Typ, Incomplete_View_From_Limited_With (Result_Subt));
Set_Etype (Formal_Typ, Formal_Typ);
Set_Depends_On_Private
(Formal_Typ, Has_Private_Component (Formal_Typ));
Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ)));
Set_Is_Access_Constant (Formal_Typ, False);
-- Ada 2005 (AI-50217): Propagate the attribute that indicates
-- the designated type comes from the limited view (for back-end
-- purposes).
Set_From_Limited_With
(Formal_Typ, From_Limited_With (Result_Subt));
Layout_Type (Formal_Typ);
-- Force the definition of the Itype in case of internal function
-- calls within the same or nested scope.
if Is_Subprogram_Or_Generic_Subprogram (E) then
Subp_Decl := Parent (E);
-- The insertion point for an Itype reference should be after
-- the unit declaration node of the subprogram. An exception
-- to this are inherited operations from a parent type in which
-- case the derived type acts as their parent.
if Nkind (Subp_Decl) in N_Function_Specification
| N_Procedure_Specification
then
Subp_Decl := Parent (Subp_Decl);
end if;
Build_Itype_Reference (Formal_Typ, Subp_Decl);
end if;
Discard :=
Add_Extra_Formal
(E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access));
end;
end if;
-- If this is an instance of a generic, we need to have extra formals
-- for the Alias.
if Is_Generic_Instance (E) and then Present (Alias (E)) then
Set_Extra_Formals (Alias (E), Extra_Formals (E));
end if;
end Create_Extra_Formals;
-----------------------------
-- Enter_Overloaded_Entity --
-----------------------------
procedure Enter_Overloaded_Entity (S : Entity_Id) is
function Matches_Predefined_Op return Boolean;
-- This returns an approximation of whether S matches a predefined
-- operator, based on the operator symbol, and the parameter and result
-- types. The rules are scattered throughout chapter 4 of the Ada RM.
---------------------------
-- Matches_Predefined_Op --
---------------------------
function Matches_Predefined_Op return Boolean is
Formal_1 : constant Entity_Id := First_Formal (S);
Formal_2 : constant Entity_Id := Next_Formal (Formal_1);
Op : constant Name_Id := Chars (S);
Result_Type : constant Entity_Id := Base_Type (Etype (S));
Type_1 : constant Entity_Id := Base_Type (Etype (Formal_1));
begin
-- Binary operator
if Present (Formal_2) then
declare
Type_2 : constant Entity_Id := Base_Type (Etype (Formal_2));
begin
-- All but "&" and "**" have same-types parameters
case Op is
when Name_Op_Concat
| Name_Op_Expon
=>
null;
when others =>
if Type_1 /= Type_2 then
return False;
end if;
end case;
-- Check parameter and result types
case Op is
when Name_Op_And
| Name_Op_Or
| Name_Op_Xor
=>
return
Is_Boolean_Type (Result_Type)
and then Result_Type = Type_1;
when Name_Op_Mod
| Name_Op_Rem
=>
return
Is_Integer_Type (Result_Type)
and then Result_Type = Type_1;
when Name_Op_Add
| Name_Op_Divide
| Name_Op_Multiply
| Name_Op_Subtract
=>
return
Is_Numeric_Type (Result_Type)
and then Result_Type = Type_1;
when Name_Op_Eq
| Name_Op_Ne
=>
return
Is_Boolean_Type (Result_Type)
and then not Is_Limited_Type (Type_1);
when Name_Op_Ge
| Name_Op_Gt
| Name_Op_Le
| Name_Op_Lt
=>
return
Is_Boolean_Type (Result_Type)
and then (Is_Array_Type (Type_1)
or else Is_Scalar_Type (Type_1));
when Name_Op_Concat =>
return Is_Array_Type (Result_Type);
when Name_Op_Expon =>
return
(Is_Integer_Type (Result_Type)
or else Is_Floating_Point_Type (Result_Type))
and then Result_Type = Type_1
and then Type_2 = Standard_Integer;
when others =>
raise Program_Error;
end case;
end;
-- Unary operator
else
case Op is
when Name_Op_Abs
| Name_Op_Add
| Name_Op_Subtract
=>
return
Is_Numeric_Type (Result_Type)
and then Result_Type = Type_1;
when Name_Op_Not =>
return
Is_Boolean_Type (Result_Type)
and then Result_Type = Type_1;
when others =>
raise Program_Error;
end case;
end if;
end Matches_Predefined_Op;
-- Local variables
E : Entity_Id := Current_Entity_In_Scope (S);
C_E : Entity_Id := Current_Entity (S);
-- Start of processing for Enter_Overloaded_Entity
begin
if Present (E) then
Set_Has_Homonym (E);
Set_Has_Homonym (S);
end if;
Set_Is_Immediately_Visible (S);
Set_Scope (S, Current_Scope);
-- Chain new entity if front of homonym in current scope, so that
-- homonyms are contiguous.
if Present (E) and then E /= C_E then
while Homonym (C_E) /= E loop
C_E := Homonym (C_E);
end loop;
Set_Homonym (C_E, S);
else
E := C_E;
Set_Current_Entity (S);
end if;
Set_Homonym (S, E);
if Is_Inherited_Operation (S) then
Append_Inherited_Subprogram (S);
else
Append_Entity (S, Current_Scope);
end if;
Set_Public_Status (S);
if Debug_Flag_E then
Write_Str ("New overloaded entity chain: ");
Write_Name (Chars (S));
E := S;
while Present (E) loop
Write_Str (" "); Write_Int (Int (E));
E := Homonym (E);
end loop;
Write_Eol;
end if;
-- Generate warning for hiding
if Warn_On_Hiding
and then Comes_From_Source (S)
and then In_Extended_Main_Source_Unit (S)
then
E := S;
loop
E := Homonym (E);
exit when No (E);
-- Warn unless genuine overloading. Do not emit warning on
-- hiding predefined operators in Standard (these are either an
-- artifact of our implicit declarations, or simple noise) but
-- keep warning on a operator defined on a local subtype, because
-- of the real danger that different operators may be applied in
-- various parts of the program.
-- Note that if E and S have the same scope, there is never any
-- hiding. Either the two conflict, and the program is illegal,
-- or S is overriding an implicit inherited subprogram.
if Scope (E) /= Scope (S)
and then (not Is_Overloadable (E)
or else Subtype_Conformant (E, S))
and then (Is_Immediately_Visible (E)
or else Is_Potentially_Use_Visible (S))
then
if Scope (E) = Standard_Standard then
if Nkind (S) = N_Defining_Operator_Symbol
and then Scope (Base_Type (Etype (First_Formal (S)))) /=
Scope (S)
and then Matches_Predefined_Op
then
Error_Msg_N
("declaration of & hides predefined operator?h?", S);
end if;
-- E not immediately within Standard
else
Error_Msg_Sloc := Sloc (E);
Error_Msg_N ("declaration of & hides one #?h?", S);
end if;
end if;
end loop;
end if;
end Enter_Overloaded_Entity;
-----------------------------
-- Check_Untagged_Equality --
-----------------------------
procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is
Typ : constant Entity_Id := Etype (First_Formal (Eq_Op));
Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op);
Obj_Decl : Node_Id;
begin
-- This check applies only if we have a subprogram declaration with an
-- untagged record type that is conformant to the predefined op.
if Nkind (Decl) /= N_Subprogram_Declaration
or else not Is_Record_Type (Typ)
or else Is_Tagged_Type (Typ)
or else Etype (Next_Formal (First_Formal (Eq_Op))) /= Typ
then
return;
end if;
-- In Ada 2012 case, we will output errors or warnings depending on
-- the setting of debug flag -gnatd.E.
if Ada_Version >= Ada_2012 then
Error_Msg_Warn := Debug_Flag_Dot_EE;
-- In earlier versions of Ada, nothing to do unless we are warning on
-- Ada 2012 incompatibilities (Warn_On_Ada_2012_Incompatibility set).
else
if not Warn_On_Ada_2012_Compatibility then
return;
end if;
end if;
-- Cases where the type has already been frozen
if Is_Frozen (Typ) then
-- The check applies to a primitive operation, so check that type
-- and equality operation are in the same scope.
if Scope (Typ) /= Current_Scope then
return;
-- If the type is a generic actual (sub)type, the operation is not
-- primitive either because the base type is declared elsewhere.
elsif Is_Generic_Actual_Type (Typ) then
return;
-- Here we have a definite error of declaration after freezing
else
if Ada_Version >= Ada_2012 then
Error_Msg_NE
("equality operator must be declared before type & is "
& "frozen (RM 4.5.2 (9.8)) (Ada 2012)<<", Eq_Op, Typ);
-- In Ada 2012 mode with error turned to warning, output one
-- more warning to warn that the equality operation may not
-- compose. This is the consequence of ignoring the error.
if Error_Msg_Warn then
Error_Msg_N ("\equality operation may not compose??", Eq_Op);
end if;
else
Error_Msg_NE
("equality operator must be declared before type& is "
& "frozen (RM 4.5.2 (9.8)) (Ada 2012)?y?", Eq_Op, Typ);
end if;
-- If we are in the package body, we could just move the
-- declaration to the package spec, so add a message saying that.
if In_Package_Body (Scope (Typ)) then
if Ada_Version >= Ada_2012 then
Error_Msg_N
("\move declaration to package spec<<", Eq_Op);
else
Error_Msg_N
("\move declaration to package spec (Ada 2012)?y?", Eq_Op);
end if;
-- Otherwise try to find the freezing point for better message.
else
Obj_Decl := Next (Parent (Typ));
while Present (Obj_Decl) and then Obj_Decl /= Decl loop
if Nkind (Obj_Decl) = N_Object_Declaration
and then Etype (Defining_Identifier (Obj_Decl)) = Typ
then
-- Freezing point, output warnings
if Ada_Version >= Ada_2012 then
Error_Msg_NE
("type& is frozen by declaration??", Obj_Decl, Typ);
Error_Msg_N
("\an equality operator cannot be declared after "
& "this point??",
Obj_Decl);
else
Error_Msg_NE
("type& is frozen by declaration (Ada 2012)?y?",
Obj_Decl, Typ);
Error_Msg_N
("\an equality operator cannot be declared after "
& "this point (Ada 2012)?y?",
Obj_Decl);
end if;
exit;
-- If we reach generated code for subprogram declaration
-- or body, it is the body that froze the type and the
-- declaration is legal.
elsif Sloc (Obj_Decl) = Sloc (Decl) then
return;
end if;
Next (Obj_Decl);
end loop;
end if;
end if;
-- Here if type is not frozen yet. It is illegal to have a primitive
-- equality declared in the private part if the type is visible
-- (RM 4.5.2(9.8)).
elsif not In_Same_List (Parent (Typ), Decl)
and then not Is_Limited_Type (Typ)
then
if Ada_Version >= Ada_2012 then
Error_Msg_N
("equality operator appears too late<<", Eq_Op);
else
Error_Msg_N
("equality operator appears too late (Ada 2012)?y?", Eq_Op);
end if;
-- Finally check for AI12-0352: declaration of a user-defined primitive
-- equality operation for a record type T is illegal if it occurs after
-- a type has been derived from T.
else
Obj_Decl := Next (Parent (Typ));
while Present (Obj_Decl) and then Obj_Decl /= Decl loop
if Nkind (Obj_Decl) = N_Full_Type_Declaration
and then Etype (Defining_Identifier (Obj_Decl)) = Typ
then
Error_Msg_N
("equality operator cannot appear after derivation", Eq_Op);
Error_Msg_NE
("an equality operator for& cannot be declared after "
& "this point??",
Obj_Decl, Typ);
end if;
Next (Obj_Decl);
end loop;
end if;
end Check_Untagged_Equality;
-----------------------------
-- Find_Corresponding_Spec --
-----------------------------
function Find_Corresponding_Spec
(N : Node_Id;
Post_Error : Boolean := True) return Entity_Id
is
Spec : constant Node_Id := Specification (N);
Designator : constant Entity_Id := Defining_Entity (Spec);
E : Entity_Id;
function Different_Generic_Profile (E : Entity_Id) return Boolean;
-- Even if fully conformant, a body may depend on a generic actual when
-- the spec does not, or vice versa, in which case they were distinct
-- entities in the generic.
-------------------------------
-- Different_Generic_Profile --
-------------------------------
function Different_Generic_Profile (E : Entity_Id) return Boolean is
F1, F2 : Entity_Id;
function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean;
-- Check that the types of corresponding formals have the same
-- generic actual if any. We have to account for subtypes of a
-- generic formal, declared between a spec and a body, which may
-- appear distinct in an instance but matched in the generic, and
-- the subtype may be used either in the spec or the body of the
-- subprogram being checked.
-------------------------
-- Same_Generic_Actual --
-------------------------
function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean is
function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean;
-- Predicate to check whether S1 is a subtype of S2 in the source
-- of the instance.
-------------------------
-- Is_Declared_Subtype --
-------------------------
function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean is
begin
return Comes_From_Source (Parent (S1))
and then Nkind (Parent (S1)) = N_Subtype_Declaration
and then Is_Entity_Name (Subtype_Indication (Parent (S1)))
and then Entity (Subtype_Indication (Parent (S1))) = S2;
end Is_Declared_Subtype;
-- Start of processing for Same_Generic_Actual
begin
return Is_Generic_Actual_Type (T1) = Is_Generic_Actual_Type (T2)
or else Is_Declared_Subtype (T1, T2)
or else Is_Declared_Subtype (T2, T1);
end Same_Generic_Actual;
-- Start of processing for Different_Generic_Profile
begin
if not In_Instance then
return False;
elsif Ekind (E) = E_Function
and then not Same_Generic_Actual (Etype (E), Etype (Designator))
then
return True;
end if;
F1 := First_Formal (Designator);
F2 := First_Formal (E);
while Present (F1) loop
if not Same_Generic_Actual (Etype (F1), Etype (F2)) then
return True;
end if;
Next_Formal (F1);
Next_Formal (F2);
end loop;
return False;
end Different_Generic_Profile;
-- Start of processing for Find_Corresponding_Spec
begin
E := Current_Entity (Designator);
while Present (E) loop
-- We are looking for a matching spec. It must have the same scope,
-- and the same name, and either be type conformant, or be the case
-- of a library procedure spec and its body (which belong to one
-- another regardless of whether they are type conformant or not).
if Scope (E) = Current_Scope then
if Current_Scope = Standard_Standard
or else (Ekind (E) = Ekind (Designator)
and then Type_Conformant (E, Designator))
then
-- Within an instantiation, we know that spec and body are
-- subtype conformant, because they were subtype conformant in
-- the generic. We choose the subtype-conformant entity here as
-- well, to resolve spurious ambiguities in the instance that
-- were not present in the generic (i.e. when two different
-- types are given the same actual). If we are looking for a
-- spec to match a body, full conformance is expected.
if In_Instance then
-- Inherit the convention and "ghostness" of the matching
-- spec to ensure proper full and subtype conformance.
Set_Convention (Designator, Convention (E));
-- Skip past subprogram bodies and subprogram renamings that
-- may appear to have a matching spec, but that aren't fully
-- conformant with it. That can occur in cases where an
-- actual type causes unrelated homographs in the instance.
if Nkind (N) in N_Subprogram_Body
| N_Subprogram_Renaming_Declaration
and then Present (Homonym (E))
and then not Fully_Conformant (Designator, E)
then
goto Next_Entity;
elsif not Subtype_Conformant (Designator, E) then
goto Next_Entity;
elsif Different_Generic_Profile (E) then
goto Next_Entity;
end if;
end if;
-- Ada 2012 (AI05-0165): For internally generated bodies of
-- null procedures locate the internally generated spec. We
-- enforce mode conformance since a tagged type may inherit
-- from interfaces several null primitives which differ only
-- in the mode of the formals.
if not (Comes_From_Source (E))
and then Is_Null_Procedure (E)
and then not Mode_Conformant (Designator, E)
then
null;
-- For null procedures coming from source that are completions,
-- analysis of the generated body will establish the link.
elsif Comes_From_Source (E)
and then Nkind (Spec) = N_Procedure_Specification
and then Null_Present (Spec)
then
return E;
-- Expression functions can be completions, but cannot be
-- completed by an explicit body.
elsif Comes_From_Source (E)
and then Comes_From_Source (N)
and then Nkind (N) = N_Subprogram_Body
and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
N_Expression_Function
then
Error_Msg_Sloc := Sloc (E);
Error_Msg_N ("body conflicts with expression function#", N);
return Empty;
elsif not Has_Completion (E) then
if Nkind (N) /= N_Subprogram_Body_Stub then
Set_Corresponding_Spec (N, E);
end if;
Set_Has_Completion (E);
return E;
elsif Nkind (Parent (N)) = N_Subunit then
-- If this is the proper body of a subunit, the completion
-- flag is set when analyzing the stub.
return E;
-- If E is an internal function with a controlling result that
-- was created for an operation inherited by a null extension,
-- it may be overridden by a body without a previous spec (one
-- more reason why these should be shunned). In that case we
-- remove the generated body if present, because the current
-- one is the explicit overriding.
elsif Ekind (E) = E_Function
and then Ada_Version >= Ada_2005
and then not Comes_From_Source (E)
and then Has_Controlling_Result (E)
and then Is_Null_Extension (Etype (E))
and then Comes_From_Source (Spec)
then
Set_Has_Completion (E, False);
if Expander_Active
and then Nkind (Parent (E)) = N_Function_Specification
then
Remove
(Unit_Declaration_Node
(Corresponding_Body (Unit_Declaration_Node (E))));
return E;
-- If expansion is disabled, or if the wrapper function has
-- not been generated yet, this a late body overriding an
-- inherited operation, or it is an overriding by some other
-- declaration before the controlling result is frozen. In
-- either case this is a declaration of a new entity.
else
return Empty;
end if;
-- If the body already exists, then this is an error unless
-- the previous declaration is the implicit declaration of a
-- derived subprogram. It is also legal for an instance to
-- contain type conformant overloadable declarations (but the
-- generic declaration may not), per 8.3(26/2).
elsif No (Alias (E))
and then not Is_Intrinsic_Subprogram (E)
and then not In_Instance
and then Post_Error
then
Error_Msg_Sloc := Sloc (E);
if Is_Imported (E) then
Error_Msg_NE
("body not allowed for imported subprogram & declared#",
N, E);
else
Error_Msg_NE ("duplicate body for & declared#", N, E);
end if;
end if;
-- Child units cannot be overloaded, so a conformance mismatch
-- between body and a previous spec is an error.
elsif Is_Child_Unit (E)
and then
Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
and then
Nkind (Parent (Unit_Declaration_Node (Designator))) =
N_Compilation_Unit
and then Post_Error
then
Error_Msg_N
("body of child unit does not match previous declaration", N);
end if;
end if;
<<Next_Entity>>
E := Homonym (E);
end loop;
-- On exit, we know that no previous declaration of subprogram exists
return Empty;
end Find_Corresponding_Spec;
----------------------
-- Fully_Conformant --
----------------------
function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
return Result;
end Fully_Conformant;
----------------------------------
-- Fully_Conformant_Expressions --
----------------------------------
function Fully_Conformant_Expressions
(Given_E1 : Node_Id;
Given_E2 : Node_Id;
Report : Boolean := False) return Boolean
is
E1 : constant Node_Id := Original_Node (Given_E1);
E2 : constant Node_Id := Original_Node (Given_E2);
-- We always test conformance on original nodes, since it is possible
-- for analysis and/or expansion to make things look as though they
-- conform when they do not, e.g. by converting 1+2 into 3.
function FCE (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean;
-- Convenience function to abbreviate recursive calls to
-- Fully_Conformant_Expressions without having to pass Report.
function FCL (L1 : List_Id; L2 : List_Id) return Boolean;
-- Compare elements of two lists for conformance. Elements have to be
-- conformant, and actuals inserted as default parameters do not match
-- explicit actuals with the same value.
function FCO (Op_Node : Node_Id; Call_Node : Node_Id) return Boolean;
-- Compare an operator node with a function call
---------
-- FCE --
---------
function FCE (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean is
begin
return Fully_Conformant_Expressions (Given_E1, Given_E2, Report);
end FCE;
---------
-- FCL --
---------
function FCL (L1 : List_Id; L2 : List_Id) return Boolean is
N1 : Node_Id;
N2 : Node_Id;
begin
if L1 = No_List then
N1 := Empty;
else
N1 := First (L1);
end if;
if L2 = No_List then
N2 := Empty;
else
N2 := First (L2);
end if;
-- Compare two lists, skipping rewrite insertions (we want to compare
-- the original trees, not the expanded versions).
loop
if Is_Rewrite_Insertion (N1) then
Next (N1);
elsif Is_Rewrite_Insertion (N2) then
Next (N2);
elsif No (N1) then
return No (N2);
elsif No (N2) then
return False;
elsif not FCE (N1, N2) then
return False;
else
Next (N1);
Next (N2);
end if;
end loop;
end FCL;
---------
-- FCO --
---------
function FCO (Op_Node : Node_Id; Call_Node : Node_Id) return Boolean is
Actuals : constant List_Id := Parameter_Associations (Call_Node);
Act : Node_Id;
begin
if No (Actuals)
or else Entity (Op_Node) /= Entity (Name (Call_Node))
then
return False;
else
Act := First (Actuals);
if Nkind (Op_Node) in N_Binary_Op then
if not FCE (Left_Opnd (Op_Node), Act) then
return False;
end if;
Next (Act);
end if;
return Present (Act)
and then FCE (Right_Opnd (Op_Node), Act)
and then No (Next (Act));
end if;
end FCO;
function User_Defined_Numeric_Literal_Mismatch return Boolean;
-- Usually literals with the same value like 12345 and 12_345
-- or 123.0 and 123.00 conform, but not if they are
-- user-defined literals.
-------------------------------------------
-- User_Defined_Numeric_Literal_Mismatch --
-------------------------------------------
function User_Defined_Numeric_Literal_Mismatch return Boolean is
E1_Is_User_Defined : constant Boolean :=
Nkind (Given_E1) not in N_Integer_Literal | N_Real_Literal;
E2_Is_User_Defined : constant Boolean :=
Nkind (Given_E2) not in N_Integer_Literal | N_Real_Literal;
begin
pragma Assert (E1_Is_User_Defined = E2_Is_User_Defined);
return E1_Is_User_Defined and then
not String_Equal (String_From_Numeric_Literal (E1),
String_From_Numeric_Literal (E2));
end User_Defined_Numeric_Literal_Mismatch;
-- Local variables
Result : Boolean;
-- Start of processing for Fully_Conformant_Expressions
begin
Result := True;
-- Nonconformant if paren count does not match. Note: if some idiot
-- complains that we don't do this right for more than 3 levels of
-- parentheses, they will be treated with the respect they deserve.
if Paren_Count (E1) /= Paren_Count (E2) then
return False;
-- If same entities are referenced, then they are conformant even if
-- they have different forms (RM 8.3.1(19-20)).
elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
if Present (Entity (E1)) then
Result := Entity (E1) = Entity (E2)
-- One may be a discriminant that has been replaced by the
-- corresponding discriminal.
or else
(Chars (Entity (E1)) = Chars (Entity (E2))
and then Ekind (Entity (E1)) = E_Discriminant
and then Ekind (Entity (E2)) = E_In_Parameter)
-- The discriminant of a protected type is transformed into
-- a local constant and then into a parameter of a protected
-- operation.
or else
(Ekind (Entity (E1)) = E_Constant
and then Ekind (Entity (E2)) = E_In_Parameter
and then Present (Discriminal_Link (Entity (E1)))
and then Discriminal_Link (Entity (E1)) =
Discriminal_Link (Entity (E2)))
-- AI12-050: The loop variables of quantified expressions match
-- if they have the same identifier, even though they may have
-- different entities.
or else
(Chars (Entity (E1)) = Chars (Entity (E2))
and then Ekind (Entity (E1)) = E_Loop_Parameter
and then Ekind (Entity (E2)) = E_Loop_Parameter)
-- A call to an instantiation of Unchecked_Conversion is
-- rewritten with the name of the generated function created for
-- the instance, and this must be special-cased.
or else
(Ekind (Entity (E1)) = E_Function
and then Is_Intrinsic_Subprogram (Entity (E1))
and then Is_Generic_Instance (Entity (E1))
and then Entity (E2) = Alias (Entity (E1)));
if Report and not Result then
Error_Msg_Sloc :=
Text_Ptr'Max (Sloc (Entity (E1)), Sloc (Entity (E2)));
Error_Msg_NE
("meaning of& differs because of declaration#", E1, E2);
end if;
return Result;
elsif Nkind (E1) = N_Expanded_Name
and then Nkind (E2) = N_Expanded_Name
and then Nkind (Selector_Name (E1)) = N_Character_Literal
and then Nkind (Selector_Name (E2)) = N_Character_Literal
then
return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
else
-- Identifiers in component associations don't always have
-- entities, but their names must conform.
return Nkind (E1) = N_Identifier
and then Nkind (E2) = N_Identifier
and then Chars (E1) = Chars (E2);
end if;
elsif Nkind (E1) = N_Character_Literal
and then Nkind (E2) = N_Expanded_Name
then
return Nkind (Selector_Name (E2)) = N_Character_Literal
and then Chars (E1) = Chars (Selector_Name (E2));
elsif Nkind (E2) = N_Character_Literal
and then Nkind (E1) = N_Expanded_Name
then
return Nkind (Selector_Name (E1)) = N_Character_Literal
and then Chars (E2) = Chars (Selector_Name (E1));
elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then
return FCO (E1, E2);
elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then
return FCO (E2, E1);
-- Otherwise we must have the same syntactic entity
elsif Nkind (E1) /= Nkind (E2) then
return False;
-- At this point, we specialize by node type
else
case Nkind (E1) is
when N_Aggregate =>
return
FCL (Expressions (E1), Expressions (E2))
and then
FCL (Component_Associations (E1),
Component_Associations (E2));
when N_Allocator =>
if Nkind (Expression (E1)) = N_Qualified_Expression
or else
Nkind (Expression (E2)) = N_Qualified_Expression
then
return FCE (Expression (E1), Expression (E2));
-- Check that the subtype marks and any constraints
-- are conformant
else
declare
Indic1 : constant Node_Id := Expression (E1);
Indic2 : constant Node_Id := Expression (E2);
Elt1 : Node_Id;
Elt2 : Node_Id;
begin
if Nkind (Indic1) /= N_Subtype_Indication then
return
Nkind (Indic2) /= N_Subtype_Indication
and then Entity (Indic1) = Entity (Indic2);
elsif Nkind (Indic2) /= N_Subtype_Indication then
return
Nkind (Indic1) /= N_Subtype_Indication
and then Entity (Indic1) = Entity (Indic2);
else
if Entity (Subtype_Mark (Indic1)) /=
Entity (Subtype_Mark (Indic2))
then
return False;
end if;
Elt1 := First (Constraints (Constraint (Indic1)));
Elt2 := First (Constraints (Constraint (Indic2)));
while Present (Elt1) and then Present (Elt2) loop
if not FCE (Elt1, Elt2) then
return False;
end if;
Next (Elt1);
Next (Elt2);
end loop;
return True;
end if;
end;
end if;
when N_Attribute_Reference =>
return
Attribute_Name (E1) = Attribute_Name (E2)
and then FCL (Expressions (E1), Expressions (E2));
when N_Binary_Op =>
return
Entity (E1) = Entity (E2)
and then FCE (Left_Opnd (E1), Left_Opnd (E2))
and then FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Membership_Test
| N_Short_Circuit
=>
return
FCE (Left_Opnd (E1), Left_Opnd (E2))
and then
FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Case_Expression =>
declare
Alt1 : Node_Id;
Alt2 : Node_Id;
begin
if not FCE (Expression (E1), Expression (E2)) then
return False;
else
Alt1 := First (Alternatives (E1));
Alt2 := First (Alternatives (E2));
loop
if Present (Alt1) /= Present (Alt2) then
return False;
elsif No (Alt1) then
return True;
end if;
if not FCE (Expression (Alt1), Expression (Alt2))
or else not FCL (Discrete_Choices (Alt1),
Discrete_Choices (Alt2))
then
return False;
end if;
Next (Alt1);
Next (Alt2);
end loop;
end if;
end;
when N_Character_Literal =>
return
Char_Literal_Value (E1) = Char_Literal_Value (E2);
when N_Component_Association =>
return
FCL (Choices (E1), Choices (E2))
and then
FCE (Expression (E1), Expression (E2));
when N_Explicit_Dereference =>
return
FCE (Prefix (E1), Prefix (E2));
when N_Extension_Aggregate =>
return
FCL (Expressions (E1), Expressions (E2))
and then Null_Record_Present (E1) =
Null_Record_Present (E2)
and then FCL (Component_Associations (E1),
Component_Associations (E2));
when N_Function_Call =>
return
FCE (Name (E1), Name (E2))
and then
FCL (Parameter_Associations (E1),
Parameter_Associations (E2));
when N_If_Expression =>
return
FCL (Expressions (E1), Expressions (E2));
when N_Indexed_Component =>
return
FCE (Prefix (E1), Prefix (E2))
and then
FCL (Expressions (E1), Expressions (E2));
when N_Integer_Literal =>
return (Intval (E1) = Intval (E2))
and then not User_Defined_Numeric_Literal_Mismatch;
when N_Null =>
return True;
when N_Operator_Symbol =>
return
Chars (E1) = Chars (E2);
when N_Others_Choice =>
return True;
when N_Parameter_Association =>
return
Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
and then FCE (Explicit_Actual_Parameter (E1),
Explicit_Actual_Parameter (E2));
when N_Qualified_Expression
| N_Type_Conversion
| N_Unchecked_Type_Conversion
=>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then
FCE (Expression (E1), Expression (E2));
when N_Quantified_Expression =>
if not FCE (Condition (E1), Condition (E2)) then
return False;
end if;
if Present (Loop_Parameter_Specification (E1))
and then Present (Loop_Parameter_Specification (E2))
then
declare
L1 : constant Node_Id :=
Loop_Parameter_Specification (E1);
L2 : constant Node_Id :=
Loop_Parameter_Specification (E2);
begin
return
Reverse_Present (L1) = Reverse_Present (L2)
and then
FCE (Defining_Identifier (L1),
Defining_Identifier (L2))
and then
FCE (Discrete_Subtype_Definition (L1),
Discrete_Subtype_Definition (L2));
end;
elsif Present (Iterator_Specification (E1))
and then Present (Iterator_Specification (E2))
then
declare
I1 : constant Node_Id := Iterator_Specification (E1);
I2 : constant Node_Id := Iterator_Specification (E2);
begin
return
FCE (Defining_Identifier (I1),
Defining_Identifier (I2))
and then
Of_Present (I1) = Of_Present (I2)
and then
Reverse_Present (I1) = Reverse_Present (I2)
and then FCE (Name (I1), Name (I2))
and then FCE (Subtype_Indication (I1),
Subtype_Indication (I2));
end;
-- The quantified expressions used different specifications to
-- walk their respective ranges.
else
return False;
end if;
when N_Range =>
return
FCE (Low_Bound (E1), Low_Bound (E2))
and then
FCE (High_Bound (E1), High_Bound (E2));
when N_Real_Literal =>
return (Realval (E1) = Realval (E2))
and then not User_Defined_Numeric_Literal_Mismatch;
when N_Selected_Component =>
return
FCE (Prefix (E1), Prefix (E2))
and then
FCE (Selector_Name (E1), Selector_Name (E2));
when N_Slice =>
return
FCE (Prefix (E1), Prefix (E2))
and then
FCE (Discrete_Range (E1), Discrete_Range (E2));
when N_String_Literal =>
declare
S1 : constant String_Id := Strval (E1);
S2 : constant String_Id := Strval (E2);
L1 : constant Nat := String_Length (S1);
L2 : constant Nat := String_Length (S2);
begin
if L1 /= L2 then
return False;
else
for J in 1 .. L1 loop
if Get_String_Char (S1, J) /=
Get_String_Char (S2, J)
then
return False;
end if;
end loop;
return True;
end if;
end;
when N_Unary_Op =>
return
Entity (E1) = Entity (E2)
and then
FCE (Right_Opnd (E1), Right_Opnd (E2));
-- All other node types cannot appear in this context. Strictly
-- we should raise a fatal internal error. Instead we just ignore
-- the nodes. This means that if anyone makes a mistake in the
-- expander and mucks an expression tree irretrievably, the result
-- will be a failure to detect a (probably very obscure) case
-- of non-conformance, which is better than bombing on some
-- case where two expressions do in fact conform.
when others =>
return True;
end case;
end if;
end Fully_Conformant_Expressions;
----------------------------------------
-- Fully_Conformant_Discrete_Subtypes --
----------------------------------------
function Fully_Conformant_Discrete_Subtypes
(Given_S1 : Node_Id;
Given_S2 : Node_Id) return Boolean
is
S1 : constant Node_Id := Original_Node (Given_S1);
S2 : constant Node_Id := Original_Node (Given_S2);
function Conforming_Bounds (B1, B2 : Node_Id) return Boolean;
-- Special-case for a bound given by a discriminant, which in the body
-- is replaced with the discriminal of the enclosing type.
function Conforming_Ranges (R1, R2 : Node_Id) return Boolean;
-- Check both bounds
-----------------------
-- Conforming_Bounds --
-----------------------
function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is
begin
if Is_Entity_Name (B1)
and then Is_Entity_Name (B2)
and then Ekind (Entity (B1)) = E_Discriminant
then
return Chars (B1) = Chars (B2);
else
return Fully_Conformant_Expressions (B1, B2);
end if;
end Conforming_Bounds;
-----------------------
-- Conforming_Ranges --
-----------------------
function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is
begin
return
Conforming_Bounds (Low_Bound (R1), Low_Bound (R2))
and then
Conforming_Bounds (High_Bound (R1), High_Bound (R2));
end Conforming_Ranges;
-- Start of processing for Fully_Conformant_Discrete_Subtypes
begin
if Nkind (S1) /= Nkind (S2) then
return False;
elsif Is_Entity_Name (S1) then
return Entity (S1) = Entity (S2);
elsif Nkind (S1) = N_Range then
return Conforming_Ranges (S1, S2);
elsif Nkind (S1) = N_Subtype_Indication then
return
Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2))
and then
Conforming_Ranges
(Range_Expression (Constraint (S1)),
Range_Expression (Constraint (S2)));
else
return True;
end if;
end Fully_Conformant_Discrete_Subtypes;
--------------------
-- Install_Entity --
--------------------
procedure Install_Entity (E : Entity_Id) is
Prev : constant Entity_Id := Current_Entity (E);
begin
Set_Is_Immediately_Visible (E);
Set_Current_Entity (E);
pragma Assert (Prev /= E);
Set_Homonym (E, Prev);
end Install_Entity;
---------------------
-- Install_Formals --
---------------------
procedure Install_Formals (Id : Entity_Id) is
F : Entity_Id;
begin
F := First_Formal (Id);
while Present (F) loop
Install_Entity (F);
Next_Formal (F);
end loop;
end Install_Formals;
-----------------------------
-- Is_Interface_Conformant --
-----------------------------
function Is_Interface_Conformant
(Tagged_Type : Entity_Id;
Iface_Prim : Entity_Id;
Prim : Entity_Id) return Boolean
is
-- The operation may in fact be an inherited (implicit) operation
-- rather than the original interface primitive, so retrieve the
-- ultimate ancestor.
Iface : constant Entity_Id :=
Find_Dispatching_Type (Ultimate_Alias (Iface_Prim));
Typ : constant Entity_Id := Find_Dispatching_Type (Prim);
function Controlling_Formal (Prim : Entity_Id) return Entity_Id;
-- Return the controlling formal of Prim
------------------------
-- Controlling_Formal --
------------------------
function Controlling_Formal (Prim : Entity_Id) return Entity_Id is
E : Entity_Id;
begin
E := First_Entity (Prim);
while Present (E) loop
if Is_Formal (E) and then Is_Controlling_Formal (E) then
return E;
end if;
Next_Entity (E);
end loop;
return Empty;
end Controlling_Formal;
-- Local variables
Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim);
Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim);
-- Start of processing for Is_Interface_Conformant
begin
pragma Assert (Is_Subprogram (Iface_Prim)
and then Is_Subprogram (Prim)
and then Is_Dispatching_Operation (Iface_Prim)
and then Is_Dispatching_Operation (Prim));
pragma Assert (Is_Interface (Iface)
or else (Present (Alias (Iface_Prim))
and then
Is_Interface
(Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
if Prim = Iface_Prim
or else not Is_Subprogram (Prim)
or else Ekind (Prim) /= Ekind (Iface_Prim)
or else not Is_Dispatching_Operation (Prim)
or else Scope (Prim) /= Scope (Tagged_Type)
or else No (Typ)
or else Base_Type (Typ) /= Base_Type (Tagged_Type)
or else not Primitive_Names_Match (Iface_Prim, Prim)
then
return False;
-- The mode of the controlling formals must match
elsif Present (Iface_Ctrl_F)
and then Present (Prim_Ctrl_F)
and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F)
then
return False;
-- Case of a procedure, or a function whose result type matches the
-- result type of the interface primitive, or a function that has no
-- controlling result (I or access I).
elsif Ekind (Iface_Prim) = E_Procedure
or else Etype (Prim) = Etype (Iface_Prim)
or else not Has_Controlling_Result (Prim)
then
return Type_Conformant
(Iface_Prim, Prim, Skip_Controlling_Formals => True);
-- Case of a function returning an interface, or an access to one. Check
-- that the return types correspond.
elsif Implements_Interface (Typ, Iface) then
if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type)
/=
(Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type)
then
return False;
else
return
Type_Conformant (Prim, Ultimate_Alias (Iface_Prim),
Skip_Controlling_Formals => True);
end if;
else
return False;
end if;
end Is_Interface_Conformant;
---------------------------------
-- Is_Non_Overriding_Operation --
---------------------------------
function Is_Non_Overriding_Operation
(Prev_E : Entity_Id;
New_E : Entity_Id) return Boolean
is
Formal : Entity_Id;
F_Typ : Entity_Id;
G_Typ : Entity_Id := Empty;
function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
-- If F_Type is a derived type associated with a generic actual subtype,
-- then return its Generic_Parent_Type attribute, else return Empty.
function Types_Correspond
(P_Type : Entity_Id;
N_Type : Entity_Id) return Boolean;
-- Returns true if and only if the types (or designated types in the
-- case of anonymous access types) are the same or N_Type is derived
-- directly or indirectly from P_Type.
-----------------------------
-- Get_Generic_Parent_Type --
-----------------------------
function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
G_Typ : Entity_Id;
Defn : Node_Id;
Indic : Node_Id;
begin
if Is_Derived_Type (F_Typ)
and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
then
-- The tree must be traversed to determine the parent subtype in
-- the generic unit, which unfortunately isn't always available
-- via semantic attributes. ??? (Note: The use of Original_Node
-- is needed for cases where a full derived type has been
-- rewritten.)
-- If the parent type is a scalar type, the derivation creates
-- an anonymous base type for it, and the source type is its
-- first subtype.
if Is_Scalar_Type (F_Typ)
and then not Comes_From_Source (F_Typ)
then
Defn :=
Type_Definition
(Original_Node (Parent (First_Subtype (F_Typ))));
else
Defn := Type_Definition (Original_Node (Parent (F_Typ)));
end if;
if Nkind (Defn) = N_Derived_Type_Definition then
Indic := Subtype_Indication (Defn);
if Nkind (Indic) = N_Subtype_Indication then
G_Typ := Entity (Subtype_Mark (Indic));
else
G_Typ := Entity (Indic);
end if;
if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
and then Present (Generic_Parent_Type (Parent (G_Typ)))
then
return Generic_Parent_Type (Parent (G_Typ));
end if;
end if;
end if;
return Empty;
end Get_Generic_Parent_Type;
----------------------
-- Types_Correspond --
----------------------
function Types_Correspond
(P_Type : Entity_Id;
N_Type : Entity_Id) return Boolean
is
Prev_Type : Entity_Id := Base_Type (P_Type);
New_Type : Entity_Id := Base_Type (N_Type);
begin
if Ekind (Prev_Type) = E_Anonymous_Access_Type then
Prev_Type := Designated_Type (Prev_Type);
end if;
if Ekind (New_Type) = E_Anonymous_Access_Type then
New_Type := Designated_Type (New_Type);
end if;
if Prev_Type = New_Type then
return True;
elsif not Is_Class_Wide_Type (New_Type) then
while Etype (New_Type) /= New_Type loop
New_Type := Etype (New_Type);
if New_Type = Prev_Type then
return True;
end if;
end loop;
end if;
return False;
end Types_Correspond;
-- Start of processing for Is_Non_Overriding_Operation
begin
-- In the case where both operations are implicit derived subprograms
-- then neither overrides the other. This can only occur in certain
-- obscure cases (e.g., derivation from homographs created in a generic
-- instantiation).
if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
return True;
elsif Ekind (Current_Scope) = E_Package
and then Is_Generic_Instance (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Comes_From_Source (New_E)
then
-- We examine the formals and result type of the inherited operation,
-- to determine whether their type is derived from (the instance of)
-- a generic type. The first such formal or result type is the one
-- tested.
Formal := First_Formal (Prev_E);
F_Typ := Empty;
while Present (Formal) loop
F_Typ := Base_Type (Etype (Formal));
if Ekind (F_Typ) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (F_Typ);
end if;
G_Typ := Get_Generic_Parent_Type (F_Typ);
exit when Present (G_Typ);
Next_Formal (Formal);
end loop;
-- If the function dispatches on result check the result type
if No (G_Typ) and then Ekind (Prev_E) = E_Function then
G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
end if;
if No (G_Typ) then
return False;
end if;
-- If the generic type is a private type, then the original operation
-- was not overriding in the generic, because there was no primitive
-- operation to override.
if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
N_Formal_Private_Type_Definition
then
return True;
-- The generic parent type is the ancestor of a formal derived
-- type declaration. We need to check whether it has a primitive
-- operation that should be overridden by New_E in the generic.
else
declare
P_Formal : Entity_Id;
N_Formal : Entity_Id;
P_Typ : Entity_Id;
N_Typ : Entity_Id;
P_Prim : Entity_Id;
Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
begin
while Present (Prim_Elt) loop
P_Prim := Node (Prim_Elt);
if Chars (P_Prim) = Chars (New_E)
and then Ekind (P_Prim) = Ekind (New_E)
then
P_Formal := First_Formal (P_Prim);
N_Formal := First_Formal (New_E);
while Present (P_Formal) and then Present (N_Formal) loop
P_Typ := Etype (P_Formal);
N_Typ := Etype (N_Formal);
if not Types_Correspond (P_Typ, N_Typ) then
exit;
end if;
Next_Formal (P_Formal);
Next_Formal (N_Formal);
end loop;
-- Found a matching primitive operation belonging to the
-- formal ancestor type, so the new subprogram is
-- overriding.
if No (P_Formal)
and then No (N_Formal)
and then (Ekind (New_E) /= E_Function
or else
Types_Correspond
(Etype (P_Prim), Etype (New_E)))
then
return False;
end if;
end if;
Next_Elmt (Prim_Elt);
end loop;
-- If no match found, then the new subprogram does not override
-- in the generic (nor in the instance).
-- If the type in question is not abstract, and the subprogram
-- is, this will be an error if the new operation is in the
-- private part of the instance. Emit a warning now, which will
-- make the subsequent error message easier to understand.
if Present (F_Typ) and then not Is_Abstract_Type (F_Typ)
and then Is_Abstract_Subprogram (Prev_E)
and then In_Private_Part (Current_Scope)
then
Error_Msg_Node_2 := F_Typ;
Error_Msg_NE
("private operation& in generic unit does not override "
& "any primitive operation of& (RM 12.3(18))??",
New_E, New_E);
end if;
return True;
end;
end if;
else
return False;
end if;
end Is_Non_Overriding_Operation;
-------------------------------------
-- List_Inherited_Pre_Post_Aspects --
-------------------------------------
procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is
begin
if Opt.List_Inherited_Aspects
and then Is_Subprogram_Or_Generic_Subprogram (E)
then
declare
Subps : constant Subprogram_List := Inherited_Subprograms (E);
Items : Node_Id;
Prag : Node_Id;
begin
for Index in Subps'Range loop
Items := Contract (Subps (Index));
if Present (Items) then
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
Error_Msg_Sloc := Sloc (Prag);
if Class_Present (Prag)
and then not Split_PPC (Prag)
then
if Pragma_Name (Prag) = Name_Precondition then
Error_Msg_N
("info: & inherits `Pre''Class` aspect from "
& "#?L?", E);
else
Error_Msg_N
("info: & inherits `Post''Class` aspect from "
& "#?L?", E);
end if;
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
end loop;
end;
end if;
end List_Inherited_Pre_Post_Aspects;
------------------------------
-- Make_Inequality_Operator --
------------------------------
-- S is the defining identifier of an equality operator. We build a
-- subprogram declaration with the right signature. This operation is
-- intrinsic, because it is always expanded as the negation of the
-- call to the equality function.
procedure Make_Inequality_Operator (S : Entity_Id) is
Loc : constant Source_Ptr := Sloc (S);
Decl : Node_Id;
Formals : List_Id;
Op_Name : Entity_Id;
FF : constant Entity_Id := First_Formal (S);
NF : constant Entity_Id := Next_Formal (FF);
begin
-- Check that equality was properly defined, ignore call if not
if No (NF) then
return;
end if;
declare
A : constant Entity_Id :=
Make_Defining_Identifier (Sloc (FF),
Chars => Chars (FF));
B : constant Entity_Id :=
Make_Defining_Identifier (Sloc (NF),
Chars => Chars (NF));
begin
Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => A,
Parameter_Type =>
New_Occurrence_Of (Etype (First_Formal (S)),
Sloc (Etype (First_Formal (S))))),
Make_Parameter_Specification (Loc,
Defining_Identifier => B,
Parameter_Type =>
New_Occurrence_Of (Etype (Next_Formal (First_Formal (S))),
Sloc (Etype (Next_Formal (First_Formal (S)))))));
Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Op_Name,
Parameter_Specifications => Formals,
Result_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc)));
-- Insert inequality right after equality if it is explicit or after
-- the derived type when implicit. These entities are created only
-- for visibility purposes, and eventually replaced in the course
-- of expansion, so they do not need to be attached to the tree and
-- seen by the back-end. Keeping them internal also avoids spurious
-- freezing problems. The declaration is inserted in the tree for
-- analysis, and removed afterwards. If the equality operator comes
-- from an explicit declaration, attach the inequality immediately
-- after. Else the equality is inherited from a derived type
-- declaration, so insert inequality after that declaration.
if No (Alias (S)) then
Insert_After (Unit_Declaration_Node (S), Decl);
elsif Is_List_Member (Parent (S)) then
Insert_After (Parent (S), Decl);
else
Insert_After (Parent (Etype (First_Formal (S))), Decl);
end if;
Mark_Rewrite_Insertion (Decl);
Set_Is_Intrinsic_Subprogram (Op_Name);
Analyze (Decl);
Remove (Decl);
Set_Has_Completion (Op_Name);
Set_Corresponding_Equality (Op_Name, S);
Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S));
end;
end Make_Inequality_Operator;
----------------------
-- May_Need_Actuals --
----------------------
procedure May_Need_Actuals (Fun : Entity_Id) is
F : Entity_Id;
B : Boolean;
begin
F := First_Formal (Fun);
B := True;
while Present (F) loop
if No (Default_Value (F)) then
B := False;
exit;
end if;
Next_Formal (F);
end loop;
Set_Needs_No_Actuals (Fun, B);
end May_Need_Actuals;
---------------------
-- Mode_Conformant --
---------------------
function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
return Result;
end Mode_Conformant;
---------------------------
-- New_Overloaded_Entity --
---------------------------
procedure New_Overloaded_Entity
(S : Entity_Id;
Derived_Type : Entity_Id := Empty)
is
Overridden_Subp : Entity_Id := Empty;
-- Set if the current scope has an operation that is type-conformant
-- with S, and becomes hidden by S.
Is_Primitive_Subp : Boolean;
-- Set to True if the new subprogram is primitive
E : Entity_Id;
-- Entity that S overrides
procedure Check_For_Primitive_Subprogram
(Is_Primitive : out Boolean;
Is_Overriding : Boolean := False);
-- If the subprogram being analyzed is a primitive operation of the type
-- of a formal or result, set the Has_Primitive_Operations flag on the
-- type, and set Is_Primitive to True (otherwise set to False). Set the
-- corresponding flag on the entity itself for later use.
function Has_Matching_Entry_Or_Subprogram (E : Entity_Id) return Boolean;
-- True if a) E is a subprogram whose first formal is a concurrent type
-- defined in the scope of E that has some entry or subprogram whose
-- profile matches E, or b) E is an internally built dispatching
-- subprogram of a protected type and there is a matching subprogram
-- defined in the enclosing scope of the protected type, or c) E is
-- an entry of a synchronized type and a matching procedure has been
-- previously defined in the enclosing scope of the synchronized type.
function Is_Private_Declaration (E : Entity_Id) return Boolean;
-- Check that E is declared in the private part of the current package,
-- or in the package body, where it may hide a previous declaration.
-- We can't use In_Private_Part by itself because this flag is also
-- set when freezing entities, so we must examine the place of the
-- declaration in the tree, and recognize wrapper packages as well.
function Is_Overriding_Alias
(Old_E : Entity_Id;
New_E : Entity_Id) return Boolean;
-- Check whether new subprogram and old subprogram are both inherited
-- from subprograms that have distinct dispatch table entries. This can
-- occur with derivations from instances with accidental homonyms. The
-- function is conservative given that the converse is only true within
-- instances that contain accidental overloadings.
procedure Report_Conflict (S : Entity_Id; E : Entity_Id);
-- Report conflict between entities S and E
------------------------------------
-- Check_For_Primitive_Subprogram --
------------------------------------
procedure Check_For_Primitive_Subprogram
(Is_Primitive : out Boolean;
Is_Overriding : Boolean := False)
is
procedure Add_Or_Replace_Untagged_Primitive (Typ : Entity_Id);
-- Either add the new subprogram to the list of primitives for
-- untagged type Typ, or if it overrides a primitive of Typ, then
-- replace the overridden primitive in Typ's primitives list with
-- the new subprogram.
function Visible_Part_Type (T : Entity_Id) return Boolean;
-- Returns true if T is declared in the visible part of the current
-- package scope; otherwise returns false. Assumes that T is declared
-- in a package.
procedure Check_Private_Overriding (T : Entity_Id);
-- Checks that if a primitive abstract subprogram of a visible
-- abstract type is declared in a private part, then it must override
-- an abstract subprogram declared in the visible part. Also checks
-- that if a primitive function with a controlling result is declared
-- in a private part, then it must override a function declared in
-- the visible part.
---------------------------------------
-- Add_Or_Replace_Untagged_Primitive --
---------------------------------------
procedure Add_Or_Replace_Untagged_Primitive (Typ : Entity_Id) is
Replaced_Overridden_Subp : Boolean := False;
begin
pragma Assert (not Is_Tagged_Type (Typ));
-- Anonymous access types don't have a primitives list. Normally
-- such types wouldn't make it here, but the case of anonymous
-- access-to-subprogram types can.
if not Is_Anonymous_Access_Type (Typ) then
-- If S overrides a subprogram that's a primitive of
-- the formal's type, then replace the overridden
-- subprogram with the new subprogram in the type's
-- list of primitives.
if Is_Overriding then
pragma Assert (Present (Overridden_Subp)
and then Overridden_Subp = E); -- Added for now
declare
Prim_Ops : constant Elist_Id :=
Primitive_Operations (Typ);
Elmt : Elmt_Id;
begin
if Present (Prim_Ops) then
Elmt := First_Elmt (Prim_Ops);
while Present (Elmt)
and then Node (Elmt) /= Overridden_Subp
loop
Next_Elmt (Elmt);
end loop;
if Present (Elmt) then
Replace_Elmt (Elmt, S);
Replaced_Overridden_Subp := True;
end if;
end if;
end;
end if;
-- If the new subprogram did not override an operation
-- of the formal's type, then add it to the primitives
-- list of the type.
if not Replaced_Overridden_Subp then
Append_Unique_Elmt (S, Primitive_Operations (Typ));
end if;
end if;
end Add_Or_Replace_Untagged_Primitive;
------------------------------
-- Check_Private_Overriding --
------------------------------
procedure Check_Private_Overriding (T : Entity_Id) is
function Overrides_Private_Part_Op return Boolean;
-- This detects the special case where the overriding subprogram
-- is overriding a subprogram that was declared in the same
-- private part. That case is illegal by 3.9.3(10).
function Overrides_Visible_Function
(Partial_View : Entity_Id) return Boolean;
-- True if S overrides a function in the visible part. The
-- overridden function could be explicitly or implicitly declared.
-------------------------------
-- Overrides_Private_Part_Op --
-------------------------------
function Overrides_Private_Part_Op return Boolean is
Over_Decl : constant Node_Id :=
Unit_Declaration_Node (Overridden_Operation (S));
Subp_Decl : constant Node_Id := Unit_Declaration_Node (S);
begin
pragma Assert (Is_Overriding);
pragma Assert
(Nkind (Over_Decl) = N_Abstract_Subprogram_Declaration);
pragma Assert
(Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration);
return In_Same_List (Over_Decl, Subp_Decl);
end Overrides_Private_Part_Op;
--------------------------------
-- Overrides_Visible_Function --
--------------------------------
function Overrides_Visible_Function
(Partial_View : Entity_Id) return Boolean
is
begin
if not Is_Overriding or else not Has_Homonym (S) then
return False;
end if;
if not Present (Partial_View) then
return True;
end if;
-- Search through all the homonyms H of S in the current
-- package spec, and return True if we find one that matches.
-- Note that Parent (H) will be the declaration of the
-- partial view of T for a match.
declare
H : Entity_Id := S;
begin
loop
H := Homonym (H);
exit when not Present (H) or else Scope (H) /= Scope (S);
if Nkind (Parent (H)) in
N_Private_Extension_Declaration |
N_Private_Type_Declaration
and then Defining_Identifier (Parent (H)) = Partial_View
then
return True;
end if;
end loop;
end;
return False;
end Overrides_Visible_Function;
-- Start of processing for Check_Private_Overriding
begin
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Visible_Part_Type (T)
and then not In_Instance
then
if Is_Abstract_Type (T)
and then Is_Abstract_Subprogram (S)
and then (not Is_Overriding
or else not Is_Abstract_Subprogram (E)
or else Overrides_Private_Part_Op)
then
Error_Msg_N
("abstract subprograms must be visible (RM 3.9.3(10))!",
S);
elsif Ekind (S) = E_Function then
declare
Partial_View : constant Entity_Id :=
Incomplete_Or_Partial_View (T);
begin
if not Overrides_Visible_Function (Partial_View) then
-- Here, S is "function ... return T;" declared in
-- the private part, not overriding some visible
-- operation. That's illegal in the tagged case
-- (but not if the private type is untagged).
if ((Present (Partial_View)
and then Is_Tagged_Type (Partial_View))
or else (not Present (Partial_View)
and then Is_Tagged_Type (T)))
and then T = Base_Type (Etype (S))
then
Error_Msg_N
("private function with tagged result must"
& " override visible-part function", S);
Error_Msg_N
("\move subprogram to the visible part"
& " (RM 3.9.3(10))", S);
-- Ada 2012 (AI05-0073): Extend this check to the case
-- of a function whose result subtype is defined by an
-- access_definition designating specific tagged type.
elsif Ekind (Etype (S)) = E_Anonymous_Access_Type
and then Is_Tagged_Type (Designated_Type (Etype (S)))
and then
not Is_Class_Wide_Type
(Designated_Type (Etype (S)))
and then Ada_Version >= Ada_2012
then
Error_Msg_N
("private function with controlling access "
& "result must override visible-part function",
S);
Error_Msg_N
("\move subprogram to the visible part"
& " (RM 3.9.3(10))", S);
end if;
end if;
end;
end if;
end if;
end Check_Private_Overriding;
-----------------------
-- Visible_Part_Type --
-----------------------
function Visible_Part_Type (T : Entity_Id) return Boolean is
P : constant Node_Id := Unit_Declaration_Node (Scope (T));
begin
-- If the entity is a private type, then it must be declared in a
-- visible part.
if Is_Private_Type (T) then
return True;
elsif Is_Type (T) and then Has_Private_Declaration (T) then
return True;
elsif Is_List_Member (Declaration_Node (T))
and then List_Containing (Declaration_Node (T)) =
Visible_Declarations (Specification (P))
then
return True;
else
return False;
end if;
end Visible_Part_Type;
-- Local variables
Formal : Entity_Id;
F_Typ : Entity_Id;
B_Typ : Entity_Id;
-- Start of processing for Check_For_Primitive_Subprogram
begin
Is_Primitive := False;
if not Comes_From_Source (S) then
-- Add an inherited primitive for an untagged derived type to
-- Derived_Type's list of primitives. Tagged primitives are dealt
-- with in Check_Dispatching_Operation.
if Present (Derived_Type)
and then Extensions_Allowed
and then not Is_Tagged_Type (Derived_Type)
then
Append_Unique_Elmt (S, Primitive_Operations (Derived_Type));
end if;
-- If subprogram is at library level, it is not primitive operation
elsif Current_Scope = Standard_Standard then
null;
elsif (Is_Package_Or_Generic_Package (Current_Scope)
and then not In_Package_Body (Current_Scope))
or else Is_Overriding
then
-- For function, check return type
if Ekind (S) = E_Function then
if Ekind (Etype (S)) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (Etype (S));
else
F_Typ := Etype (S);
end if;
B_Typ := Base_Type (F_Typ);
if Scope (B_Typ) = Current_Scope
and then not Is_Class_Wide_Type (B_Typ)
and then not Is_Generic_Type (B_Typ)
then
Is_Primitive := True;
Set_Has_Primitive_Operations (B_Typ);
Set_Is_Primitive (S);
-- Add a primitive for an untagged type to B_Typ's list
-- of primitives. Tagged primitives are dealt with in
-- Check_Dispatching_Operation.
if Extensions_Allowed
and then not Is_Tagged_Type (B_Typ)
then
Add_Or_Replace_Untagged_Primitive (B_Typ);
end if;
Check_Private_Overriding (B_Typ);
-- The Ghost policy in effect at the point of declaration
-- or a tagged type and a primitive operation must match
-- (SPARK RM 6.9(16)).
Check_Ghost_Primitive (S, B_Typ);
end if;
end if;
-- For all subprograms, check formals
Formal := First_Formal (S);
while Present (Formal) loop
if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (Etype (Formal));
else
F_Typ := Etype (Formal);
end if;
B_Typ := Base_Type (F_Typ);
if Ekind (B_Typ) = E_Access_Subtype then
B_Typ := Base_Type (B_Typ);
end if;
if Scope (B_Typ) = Current_Scope
and then not Is_Class_Wide_Type (B_Typ)
and then not Is_Generic_Type (B_Typ)
then
Is_Primitive := True;
Set_Is_Primitive (S);
Set_Has_Primitive_Operations (B_Typ);
-- Add a primitive for an untagged type to B_Typ's list
-- of primitives. Tagged primitives are dealt with in
-- Check_Dispatching_Operation.
if Extensions_Allowed
and then not Is_Tagged_Type (B_Typ)
then
Add_Or_Replace_Untagged_Primitive (B_Typ);
end if;
Check_Private_Overriding (B_Typ);
-- The Ghost policy in effect at the point of declaration
-- of a tagged type and a primitive operation must match
-- (SPARK RM 6.9(16)).
Check_Ghost_Primitive (S, B_Typ);
end if;
Next_Formal (Formal);
end loop;
-- Special case: An equality function can be redefined for a type
-- occurring in a declarative part, and won't otherwise be treated as
-- a primitive because it doesn't occur in a package spec and doesn't
-- override an inherited subprogram. It's important that we mark it
-- primitive so it can be returned by Collect_Primitive_Operations
-- and be used in composing the equality operation of later types
-- that have a component of the type.
elsif Chars (S) = Name_Op_Eq
and then Etype (S) = Standard_Boolean
then
B_Typ := Base_Type (Etype (First_Formal (S)));
if Scope (B_Typ) = Current_Scope
and then
Base_Type (Etype (Next_Formal (First_Formal (S)))) = B_Typ
and then not Is_Limited_Type (B_Typ)
then
Is_Primitive := True;
Set_Is_Primitive (S);
Set_Has_Primitive_Operations (B_Typ);
Check_Private_Overriding (B_Typ);
-- The Ghost policy in effect at the point of declaration of a
-- tagged type and a primitive operation must match
-- (SPARK RM 6.9(16)).
Check_Ghost_Primitive (S, B_Typ);
end if;
end if;
end Check_For_Primitive_Subprogram;
--------------------------------------
-- Has_Matching_Entry_Or_Subprogram --
--------------------------------------
function Has_Matching_Entry_Or_Subprogram
(E : Entity_Id) return Boolean
is
function Check_Conforming_Parameters
(E1_Param : Node_Id;
E2_Param : Node_Id;
Ctype : Conformance_Type) return Boolean;
-- Starting from the given parameters, check that all the parameters
-- of two entries or subprograms are conformant. Used to skip
-- the check on the controlling argument.
function Matching_Entry_Or_Subprogram
(Conc_Typ : Entity_Id;
Subp : Entity_Id) return Entity_Id;
-- Return the first entry or subprogram of the given concurrent type
-- whose name matches the name of Subp and has a profile conformant
-- with Subp; return Empty if not found.
function Matching_Dispatching_Subprogram
(Conc_Typ : Entity_Id;
Ent : Entity_Id) return Entity_Id;
-- Return the first dispatching primitive of Conc_Type defined in the
-- enclosing scope of Conc_Type (i.e. before the full definition of
-- this concurrent type) whose name matches the entry Ent and has a
-- profile conformant with the profile of the corresponding (not yet
-- built) dispatching primitive of Ent; return Empty if not found.
function Matching_Original_Protected_Subprogram
(Prot_Typ : Entity_Id;
Subp : Entity_Id) return Entity_Id;
-- Return the first subprogram defined in the enclosing scope of
-- Prot_Typ (before the full definition of this protected type)
-- whose name matches the original name of Subp and has a profile
-- conformant with the profile of Subp; return Empty if not found.
function Normalized_First_Parameter_Type
(E : Entity_Id) return Entity_Id;
-- Return the type of the first parameter unless that type
-- is an anonymous access type, in which case return the
-- designated type. Used to treat anonymous-access-to-synchronized
-- the same as synchronized for purposes of checking for
-- prefixed view profile conflicts.
---------------------------------
-- Check_Conforming_Parameters --
---------------------------------
function Check_Conforming_Parameters
(E1_Param : Node_Id;
E2_Param : Node_Id;
Ctype : Conformance_Type) return Boolean
is
Param_E1 : Node_Id := E1_Param;
Param_E2 : Node_Id := E2_Param;
begin
while Present (Param_E1) and then Present (Param_E2) loop
if (Ctype >= Mode_Conformant) and then
Ekind (Defining_Identifier (Param_E1)) /=
Ekind (Defining_Identifier (Param_E2))
then
return False;
elsif not
Conforming_Types
(Find_Parameter_Type (Param_E1),
Find_Parameter_Type (Param_E2),
Ctype)
then
return False;
end if;
Next (Param_E1);
Next (Param_E2);
end loop;
-- The candidate is not valid if one of the two lists contains
-- more parameters than the other
return No (Param_E1) and then No (Param_E2);
end Check_Conforming_Parameters;
----------------------------------
-- Matching_Entry_Or_Subprogram --
----------------------------------
function Matching_Entry_Or_Subprogram
(Conc_Typ : Entity_Id;
Subp : Entity_Id) return Entity_Id
is
E : Entity_Id;
begin
E := First_Entity (Conc_Typ);
while Present (E) loop
if Chars (Subp) = Chars (E)
and then (Ekind (E) = E_Entry or else Is_Subprogram (E))
and then
Check_Conforming_Parameters
(First (Parameter_Specifications (Parent (E))),
Next (First (Parameter_Specifications (Parent (Subp)))),
Type_Conformant)
then
return E;
end if;
Next_Entity (E);
end loop;
return Empty;
end Matching_Entry_Or_Subprogram;
-------------------------------------
-- Matching_Dispatching_Subprogram --
-------------------------------------
function Matching_Dispatching_Subprogram
(Conc_Typ : Entity_Id;
Ent : Entity_Id) return Entity_Id
is
E : Entity_Id;
begin
-- Search for entities in the enclosing scope of this synchonized
-- type.
pragma Assert (Is_Concurrent_Type (Conc_Typ));
Push_Scope (Scope (Conc_Typ));
E := Current_Entity_In_Scope (Ent);
Pop_Scope;
while Present (E) loop
if Scope (E) = Scope (Conc_Typ)
and then Comes_From_Source (E)
and then Ekind (E) = E_Procedure
and then Present (First_Entity (E))
and then Is_Controlling_Formal (First_Entity (E))
and then Etype (First_Entity (E)) = Conc_Typ
and then
Check_Conforming_Parameters
(First (Parameter_Specifications (Parent (Ent))),
Next (First (Parameter_Specifications (Parent (E)))),
Subtype_Conformant)
then
return E;
end if;
E := Homonym (E);
end loop;
return Empty;
end Matching_Dispatching_Subprogram;
--------------------------------------------
-- Matching_Original_Protected_Subprogram --
--------------------------------------------
function Matching_Original_Protected_Subprogram
(Prot_Typ : Entity_Id;
Subp : Entity_Id) return Entity_Id
is
ICF : constant Boolean :=
Is_Controlling_Formal (First_Entity (Subp));
E : Entity_Id;
begin
-- Temporarily decorate the first parameter of Subp as controlling
-- formal, required to invoke Subtype_Conformant.
Set_Is_Controlling_Formal (First_Entity (Subp));
E :=
Current_Entity_In_Scope (Original_Protected_Subprogram (Subp));
while Present (E) loop
if Scope (E) = Scope (Prot_Typ)
and then Comes_From_Source (E)
and then Ekind (Subp) = Ekind (E)
and then Present (First_Entity (E))
and then Is_Controlling_Formal (First_Entity (E))
and then Etype (First_Entity (E)) = Prot_Typ
and then Subtype_Conformant (Subp, E,
Skip_Controlling_Formals => True)
then
Set_Is_Controlling_Formal (First_Entity (Subp), ICF);
return E;
end if;
E := Homonym (E);
end loop;
Set_Is_Controlling_Formal (First_Entity (Subp), ICF);
return Empty;
end Matching_Original_Protected_Subprogram;
-------------------------------------
-- Normalized_First_Parameter_Type --
-------------------------------------
function Normalized_First_Parameter_Type
(E : Entity_Id) return Entity_Id
is
Result : Entity_Id := Etype (First_Entity (E));
begin
if Ekind (Result) = E_Anonymous_Access_Type then
Result := Designated_Type (Result);
end if;
return Result;
end Normalized_First_Parameter_Type;
-- Start of processing for Has_Matching_Entry_Or_Subprogram
begin
-- Case 1: E is a subprogram whose first formal is a concurrent type
-- defined in the scope of E that has an entry or subprogram whose
-- profile matches E.
if Comes_From_Source (E)
and then Is_Subprogram (E)
and then Present (First_Entity (E))
and then Is_Concurrent_Record_Type
(Normalized_First_Parameter_Type (E))
then
if Scope (E) =
Scope (Corresponding_Concurrent_Type
(Normalized_First_Parameter_Type (E)))
and then
Present
(Matching_Entry_Or_Subprogram
(Corresponding_Concurrent_Type
(Normalized_First_Parameter_Type (E)),
Subp => E))
then
Report_Conflict (E,
Matching_Entry_Or_Subprogram
(Corresponding_Concurrent_Type
(Normalized_First_Parameter_Type (E)),
Subp => E));
return True;
end if;
-- Case 2: E is an internally built dispatching subprogram of a
-- protected type and there is a subprogram defined in the enclosing
-- scope of the protected type that has the original name of E and
-- its profile is conformant with the profile of E. We check the
-- name of the original protected subprogram associated with E since
-- the expander builds dispatching primitives of protected functions
-- and procedures with other names (see Exp_Ch9.Build_Selected_Name).
elsif not Comes_From_Source (E)
and then Is_Subprogram (E)
and then Present (First_Entity (E))
and then Is_Concurrent_Record_Type (Etype (First_Entity (E)))
and then Present (Original_Protected_Subprogram (E))
and then
Present
(Matching_Original_Protected_Subprogram
(Corresponding_Concurrent_Type (Etype (First_Entity (E))),
Subp => E))
then
Report_Conflict (E,
Matching_Original_Protected_Subprogram
(Corresponding_Concurrent_Type (Etype (First_Entity (E))),
Subp => E));
return True;
-- Case 3: E is an entry of a synchronized type and a matching
-- procedure has been previously defined in the enclosing scope
-- of the synchronized type.
elsif Comes_From_Source (E)
and then Ekind (E) = E_Entry
and then
Present (Matching_Dispatching_Subprogram (Current_Scope, E))
then
Report_Conflict (E,
Matching_Dispatching_Subprogram (Current_Scope, E));
return True;
end if;
return False;
end Has_Matching_Entry_Or_Subprogram;
----------------------------
-- Is_Private_Declaration --
----------------------------
function Is_Private_Declaration (E : Entity_Id) return Boolean is
Decl : constant Node_Id := Unit_Declaration_Node (E);
Priv_Decls : List_Id;
begin
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
then
Priv_Decls :=
Private_Declarations (Package_Specification (Current_Scope));
return In_Package_Body (Current_Scope)
or else
(Is_List_Member (Decl)
and then List_Containing (Decl) = Priv_Decls)
or else (Nkind (Parent (Decl)) = N_Package_Specification
and then not
Is_Compilation_Unit
(Defining_Entity (Parent (Decl)))
and then List_Containing (Parent (Parent (Decl))) =
Priv_Decls);
else
return False;
end if;
end Is_Private_Declaration;
--------------------------
-- Is_Overriding_Alias --
--------------------------
function Is_Overriding_Alias
(Old_E : Entity_Id;
New_E : Entity_Id) return Boolean
is
AO : constant Entity_Id := Alias (Old_E);
AN : constant Entity_Id := Alias (New_E);
begin
return Scope (AO) /= Scope (AN)
or else No (DTC_Entity (AO))
or else No (DTC_Entity (AN))
or else DT_Position (AO) = DT_Position (AN);
end Is_Overriding_Alias;
---------------------
-- Report_Conflict --
---------------------
procedure Report_Conflict (S : Entity_Id; E : Entity_Id) is
begin
Error_Msg_Sloc := Sloc (E);
-- Generate message, with useful additional warning if in generic
if Is_Generic_Unit (E) then
Error_Msg_N ("previous generic unit cannot be overloaded", S);
Error_Msg_N ("\& conflicts with declaration#", S);
else
Error_Msg_N ("& conflicts with declaration#", S);
end if;
end Report_Conflict;
-- Start of processing for New_Overloaded_Entity
begin
-- We need to look for an entity that S may override. This must be a
-- homonym in the current scope, so we look for the first homonym of
-- S in the current scope as the starting point for the search.
E := Current_Entity_In_Scope (S);
-- Ada 2005 (AI-251): Derivation of abstract interface primitives.
-- They are directly added to the list of primitive operations of
-- Derived_Type, unless this is a rederivation in the private part
-- of an operation that was already derived in the visible part of
-- the current package.
if Ada_Version >= Ada_2005
and then Present (Derived_Type)
and then Present (Alias (S))
and then Is_Dispatching_Operation (Alias (S))
and then Present (Find_Dispatching_Type (Alias (S)))
and then Is_Interface (Find_Dispatching_Type (Alias (S)))
then
-- For private types, when the full-view is processed we propagate to
-- the full view the non-overridden entities whose attribute "alias"
-- references an interface primitive. These entities were added by
-- Derive_Subprograms to ensure that interface primitives are
-- covered.
-- Inside_Freeze_Actions is non zero when S corresponds with an
-- internal entity that links an interface primitive with its
-- covering primitive through attribute Interface_Alias (see
-- Add_Internal_Interface_Entities).
if Inside_Freezing_Actions = 0
and then Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Parent_Kind (E) = N_Private_Extension_Declaration
and then Nkind (Parent (S)) = N_Full_Type_Declaration
and then Full_View (Defining_Identifier (Parent (E)))
= Defining_Identifier (Parent (S))
and then Alias (E) = Alias (S)
then
Check_Operation_From_Private_View (S, E);
Set_Is_Dispatching_Operation (S);
-- Common case
else
Enter_Overloaded_Entity (S);
Check_Dispatching_Operation (S, Empty);
Check_For_Primitive_Subprogram (Is_Primitive_Subp);
end if;
return;
end if;
-- For synchronized types check conflicts of this entity with previously
-- defined entities.
if Ada_Version >= Ada_2005
and then Has_Matching_Entry_Or_Subprogram (S)
then
return;
end if;
-- If there is no homonym then this is definitely not overriding
if No (E) then
Enter_Overloaded_Entity (S);
Check_Dispatching_Operation (S, Empty);
Check_For_Primitive_Subprogram (Is_Primitive_Subp);
-- If subprogram has an explicit declaration, check whether it has an
-- overriding indicator.
if Comes_From_Source (S) then
Check_Synchronized_Overriding (S, Overridden_Subp);
-- (Ada 2012: AI05-0125-1): If S is a dispatching operation then
-- it may have overridden some hidden inherited primitive. Update
-- Overridden_Subp to avoid spurious errors when checking the
-- overriding indicator.
if Ada_Version >= Ada_2012
and then No (Overridden_Subp)
and then Is_Dispatching_Operation (S)
and then Present (Overridden_Operation (S))
then
Overridden_Subp := Overridden_Operation (S);
end if;
Check_Overriding_Indicator
(S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp);
-- The Ghost policy in effect at the point of declaration of a
-- parent subprogram and an overriding subprogram must match
-- (SPARK RM 6.9(17)).
Check_Ghost_Overriding (S, Overridden_Subp);
end if;
-- If there is a homonym that is not overloadable, then we have an
-- error, except for the special cases checked explicitly below.
elsif not Is_Overloadable (E) then
-- Check for spurious conflict produced by a subprogram that has the
-- same name as that of the enclosing generic package. The conflict
-- occurs within an instance, between the subprogram and the renaming
-- declaration for the package. After the subprogram, the package
-- renaming declaration becomes hidden.
if Ekind (E) = E_Package
and then Present (Renamed_Object (E))
and then Renamed_Object (E) = Current_Scope
and then Nkind (Parent (Renamed_Object (E))) =
N_Package_Specification
and then Present (Generic_Parent (Parent (Renamed_Object (E))))
then
Set_Is_Hidden (E);
Set_Is_Immediately_Visible (E, False);
Enter_Overloaded_Entity (S);
Set_Homonym (S, Homonym (E));
Check_Dispatching_Operation (S, Empty);
Check_Overriding_Indicator (S, Empty, Is_Primitive => False);
-- If the subprogram is implicit it is hidden by the previous
-- declaration. However if it is dispatching, it must appear in the
-- dispatch table anyway, because it can be dispatched to even if it
-- cannot be called directly.
elsif Present (Alias (S)) and then not Comes_From_Source (S) then
Set_Scope (S, Current_Scope);
if Is_Dispatching_Operation (Alias (S)) then
Check_Dispatching_Operation (S, Empty);
end if;
return;
else
Report_Conflict (S, E);
return;
end if;
-- E exists and is overloadable
else
Check_Synchronized_Overriding (S, Overridden_Subp);
-- Loop through E and its homonyms to determine if any of them is
-- the candidate for overriding by S.
while Present (E) loop
-- Definitely not interesting if not in the current scope
if Scope (E) /= Current_Scope then
null;
-- A function can overload the name of an abstract state. The
-- state can be viewed as a function with a profile that cannot
-- be matched by anything.
elsif Ekind (S) = E_Function
and then Ekind (E) = E_Abstract_State
then
Enter_Overloaded_Entity (S);
return;
-- Ada 2012 (AI05-0165): For internally generated bodies of null
-- procedures locate the internally generated spec. We enforce
-- mode conformance since a tagged type may inherit from
-- interfaces several null primitives which differ only in
-- the mode of the formals.
elsif not Comes_From_Source (S)
and then Is_Null_Procedure (S)
and then not Mode_Conformant (E, S)
then
null;
-- Check if we have type conformance
elsif Type_Conformant (E, S) then
-- If the old and new entities have the same profile and one
-- is not the body of the other, then this is an error, unless
-- one of them is implicitly declared.
-- There are some cases when both can be implicit, for example
-- when both a literal and a function that overrides it are
-- inherited in a derivation, or when an inherited operation
-- of a tagged full type overrides the inherited operation of
-- a private extension. Ada 83 had a special rule for the
-- literal case. In Ada 95, the later implicit operation hides
-- the former, and the literal is always the former. In the
-- odd case where both are derived operations declared at the
-- same point, both operations should be declared, and in that
-- case we bypass the following test and proceed to the next
-- part. This can only occur for certain obscure cases in
-- instances, when an operation on a type derived from a formal
-- private type does not override a homograph inherited from
-- the actual. In subsequent derivations of such a type, the
-- DT positions of these operations remain distinct, if they
-- have been set.
if Present (Alias (S))
and then (No (Alias (E))
or else Comes_From_Source (E)
or else Is_Abstract_Subprogram (S)
or else
(Is_Dispatching_Operation (E)
and then Is_Overriding_Alias (E, S)))
and then Ekind (E) /= E_Enumeration_Literal
then
-- When an derived operation is overloaded it may be due to
-- the fact that the full view of a private extension
-- re-inherits. It has to be dealt with.
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
then
Check_Operation_From_Private_View (S, E);
end if;
-- In any case the implicit operation remains hidden by the
-- existing declaration, which is overriding. Indicate that
-- E overrides the operation from which S is inherited.
if Present (Alias (S)) then
Set_Overridden_Operation (E, Alias (S));
Inherit_Subprogram_Contract (E, Alias (S));
Set_Is_Ada_2022_Only (E,
Is_Ada_2022_Only (Alias (S)));
else
Set_Overridden_Operation (E, S);
Inherit_Subprogram_Contract (E, S);
Set_Is_Ada_2022_Only (E, Is_Ada_2022_Only (S));
end if;
-- When a dispatching operation overrides an inherited
-- subprogram, it shall be subtype conformant with the
-- inherited subprogram (RM 3.9.2 (10.2)).
if Comes_From_Source (E)
and then Is_Dispatching_Operation (E)
and then Find_Dispatching_Type (S)
= Find_Dispatching_Type (E)
then
Check_Subtype_Conformant (E, S);
end if;
if Comes_From_Source (E) then
Check_Overriding_Indicator (E, S, Is_Primitive => False);
-- The Ghost policy in effect at the point of declaration
-- of a parent subprogram and an overriding subprogram
-- must match (SPARK RM 6.9(17)).
Check_Ghost_Overriding (E, S);
end if;
return;
-- Within an instance, the renaming declarations for actual
-- subprograms may become ambiguous, but they do not hide each
-- other.
elsif Ekind (E) /= E_Entry
and then not Comes_From_Source (E)
and then not Is_Generic_Instance (E)
and then (Present (Alias (E))
or else Is_Intrinsic_Subprogram (E))
and then (not In_Instance
or else No (Parent (E))
or else Nkind (Unit_Declaration_Node (E)) /=
N_Subprogram_Renaming_Declaration)
then
-- A subprogram child unit is not allowed to override an
-- inherited subprogram (10.1.1(20)).
if Is_Child_Unit (S) then
Error_Msg_N
("child unit overrides inherited subprogram in parent",
S);
return;
end if;
if Is_Non_Overriding_Operation (E, S) then
Enter_Overloaded_Entity (S);
if No (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
Check_Dispatching_Operation (S, Empty);
end if;
return;
end if;
-- E is a derived operation or an internal operator which
-- is being overridden. Remove E from further visibility.
-- Furthermore, if E is a dispatching operation, it must be
-- replaced in the list of primitive operations of its type
-- (see Override_Dispatching_Operation).
Overridden_Subp := E;
-- It is possible for E to be in the current scope and
-- yet not in the entity chain. This can only occur in a
-- generic context where E is an implicit concatenation
-- in the formal part, because in a generic body the
-- entity chain starts with the formals.
-- In GNATprove mode, a wrapper for an operation with
-- axiomatization may be a homonym of another declaration
-- for an actual subprogram (needs refinement ???).
if No (Prev_Entity (E)) then
if In_Instance
and then GNATprove_Mode
and then
Nkind (Original_Node (Unit_Declaration_Node (S))) =
N_Subprogram_Renaming_Declaration
then
return;
else
pragma Assert (Chars (E) = Name_Op_Concat);
null;
end if;
end if;
-- E must be removed both from the entity_list of the
-- current scope, and from the visibility chain.
if Debug_Flag_E then
Write_Str ("Override implicit operation ");
Write_Int (Int (E));
Write_Eol;
end if;
-- If E is a predefined concatenation, it stands for four
-- different operations. As a result, a single explicit
-- declaration does not hide it. In a possible ambiguous
-- situation, Disambiguate chooses the user-defined op,
-- so it is correct to retain the previous internal one.
if Chars (E) /= Name_Op_Concat
or else Ekind (E) /= E_Operator
then
-- For nondispatching derived operations that are
-- overridden by a subprogram declared in the private
-- part of a package, we retain the derived subprogram
-- but mark it as not immediately visible. If the
-- derived operation was declared in the visible part
-- then this ensures that it will still be visible
-- outside the package with the proper signature
-- (calls from outside must also be directed to this
-- version rather than the overriding one, unlike the
-- dispatching case). Calls from inside the package
-- will still resolve to the overriding subprogram
-- since the derived one is marked as not visible
-- within the package.
-- If the private operation is dispatching, we achieve
-- the overriding by keeping the implicit operation
-- but setting its alias to be the overriding one. In
-- this fashion the proper body is executed in all
-- cases, but the original signature is used outside
-- of the package.
-- If the overriding is not in the private part, we
-- remove the implicit operation altogether.
if Is_Private_Declaration (S) then
if not Is_Dispatching_Operation (E) then
Set_Is_Immediately_Visible (E, False);
else
-- Work done in Override_Dispatching_Operation, so
-- nothing else needs to be done here.
null;
end if;
else
Remove_Entity_And_Homonym (E);
end if;
end if;
Enter_Overloaded_Entity (S);
-- For entities generated by Derive_Subprograms the
-- overridden operation is the inherited primitive
-- (which is available through the attribute alias).
if not (Comes_From_Source (E))
and then Is_Dispatching_Operation (E)
and then Find_Dispatching_Type (E) =
Find_Dispatching_Type (S)
and then Present (Alias (E))
and then Comes_From_Source (Alias (E))
then
Set_Overridden_Operation (S, Alias (E));
Inherit_Subprogram_Contract (S, Alias (E));
Set_Is_Ada_2022_Only (S,
Is_Ada_2022_Only (Alias (E)));
-- Normal case of setting entity as overridden
-- Note: Static_Initialization and Overridden_Operation
-- attributes use the same field in subprogram entities.
-- Static_Initialization is only defined for internal
-- initialization procedures, where Overridden_Operation
-- is irrelevant. Therefore the setting of this attribute
-- must check whether the target is an init_proc.
elsif not Is_Init_Proc (S) then
-- LSP wrappers must override the ultimate alias of their
-- wrapped dispatching primitive E; required to traverse
-- the chain of ancestor primitives (c.f. Map_Primitives)
-- They don't inherit contracts.
if Is_Wrapper (S)
and then Present (LSP_Subprogram (S))
then
Set_Overridden_Operation (S, Ultimate_Alias (E));
else
Set_Overridden_Operation (S, E);
Inherit_Subprogram_Contract (S, E);
end if;
Set_Is_Ada_2022_Only (S, Is_Ada_2022_Only (E));
end if;
Check_Overriding_Indicator (S, E, Is_Primitive => True);
-- The Ghost policy in effect at the point of declaration
-- of a parent subprogram and an overriding subprogram
-- must match (SPARK RM 6.9(17)).
Check_Ghost_Overriding (S, E);
-- If S is a user-defined subprogram or a null procedure
-- expanded to override an inherited null procedure, or a
-- predefined dispatching primitive then indicate that E
-- overrides the operation from which S is inherited.
if Comes_From_Source (S)
or else
(Present (Parent (S))
and then Nkind (Parent (S)) = N_Procedure_Specification
and then Null_Present (Parent (S)))
or else
(Present (Alias (E))
and then
Is_Predefined_Dispatching_Operation (Alias (E)))
then
if Present (Alias (E)) then
-- LSP wrappers must override the ultimate alias of
-- their wrapped dispatching primitive E; required to
-- traverse the chain of ancestor primitives (see
-- Map_Primitives). They don't inherit contracts.
if Is_Wrapper (S)
and then Present (LSP_Subprogram (S))
then
Set_Overridden_Operation (S, Ultimate_Alias (E));
else
Set_Overridden_Operation (S, Alias (E));
Inherit_Subprogram_Contract (S, Alias (E));
end if;
Set_Is_Ada_2022_Only (S, Is_Ada_2022_Only (Alias (E)));
end if;
end if;
if Is_Dispatching_Operation (E) then
-- An overriding dispatching subprogram inherits the
-- convention of the overridden subprogram (AI-117).
Set_Convention (S, Convention (E));
Check_Dispatching_Operation (S, E);
else
Check_Dispatching_Operation (S, Empty);
end if;
Check_For_Primitive_Subprogram
(Is_Primitive_Subp, Is_Overriding => True);
goto Check_Inequality;
-- Apparent redeclarations in instances can occur when two
-- formal types get the same actual type. The subprograms in
-- in the instance are legal, even if not callable from the
-- outside. Calls from within are disambiguated elsewhere.
-- For dispatching operations in the visible part, the usual
-- rules apply, and operations with the same profile are not
-- legal (B830001).
elsif (In_Instance_Visible_Part
and then not Is_Dispatching_Operation (E))
or else In_Instance_Not_Visible
then
null;
-- Here we have a real error (identical profile)
else
Error_Msg_Sloc := Sloc (E);
-- Avoid cascaded errors if the entity appears in
-- subsequent calls.
Set_Scope (S, Current_Scope);
-- Generate error, with extra useful warning for the case
-- of a generic instance with no completion.
if Is_Generic_Instance (S)
and then not Has_Completion (E)
then
Error_Msg_N
("instantiation cannot provide body for&", S);
Error_Msg_N ("\& conflicts with declaration#", S);
else
Error_Msg_N ("& conflicts with declaration#", S);
end if;
return;
end if;
else
-- If one subprogram has an access parameter and the other
-- a parameter of an access type, calls to either might be
-- ambiguous. Verify that parameters match except for the
-- access parameter.
if May_Hide_Profile then
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (S);
F2 := First_Formal (E);
while Present (F1) and then Present (F2) loop
if Is_Access_Type (Etype (F1)) then
if not Is_Access_Type (Etype (F2))
or else not Conforming_Types
(Designated_Type (Etype (F1)),
Designated_Type (Etype (F2)),
Type_Conformant)
then
May_Hide_Profile := False;
end if;
elsif
not Conforming_Types
(Etype (F1), Etype (F2), Type_Conformant)
then
May_Hide_Profile := False;
end if;
Next_Formal (F1);
Next_Formal (F2);
end loop;
if May_Hide_Profile
and then No (F1)
and then No (F2)
then
Error_Msg_NE ("calls to& may be ambiguous??", S, S);
end if;
end;
end if;
end if;
E := Homonym (E);
end loop;
-- On exit, we know that S is a new entity
Enter_Overloaded_Entity (S);
Check_For_Primitive_Subprogram (Is_Primitive_Subp);
Check_Overriding_Indicator
(S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp);
-- The Ghost policy in effect at the point of declaration of a parent
-- subprogram and an overriding subprogram must match
-- (SPARK RM 6.9(17)).
Check_Ghost_Overriding (S, Overridden_Subp);
-- If S is a derived operation for an untagged type then by
-- definition it's not a dispatching operation (even if the parent
-- operation was dispatching), so Check_Dispatching_Operation is not
-- called in that case.
if No (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
Check_Dispatching_Operation (S, Empty);
end if;
end if;
-- If this is a user-defined equality operator that is not a derived
-- subprogram, create the corresponding inequality. If the operation is
-- dispatching, the expansion is done elsewhere, and we do not create
-- an explicit inequality operation.
<<Check_Inequality>>
if Chars (S) = Name_Op_Eq
and then Etype (S) = Standard_Boolean
and then Present (Parent (S))
and then not Is_Dispatching_Operation (S)
then
Make_Inequality_Operator (S);
Check_Untagged_Equality (S);
end if;
end New_Overloaded_Entity;
----------------------------------
-- Preanalyze_Formal_Expression --
----------------------------------
procedure Preanalyze_Formal_Expression (N : Node_Id; T : Entity_Id) is
Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
begin
In_Spec_Expression := True;
Preanalyze_With_Freezing_And_Resolve (N, T);
In_Spec_Expression := Save_In_Spec_Expression;
end Preanalyze_Formal_Expression;
---------------------
-- Process_Formals --
---------------------
procedure Process_Formals
(T : List_Id;
Related_Nod : Node_Id)
is
function Designates_From_Limited_With (Typ : Entity_Id) return Boolean;
-- Determine whether an access type designates a type coming from a
-- limited view.
function Is_Class_Wide_Default (D : Node_Id) return Boolean;
-- Check whether the default has a class-wide type. After analysis the
-- default has the type of the formal, so we must also check explicitly
-- for an access attribute.
----------------------------------
-- Designates_From_Limited_With --
----------------------------------
function Designates_From_Limited_With (Typ : Entity_Id) return Boolean is
Desig : Entity_Id := Typ;
begin
if Is_Access_Type (Desig) then
Desig := Directly_Designated_Type (Desig);
end if;
if Is_Class_Wide_Type (Desig) then
Desig := Root_Type (Desig);
end if;
return
Ekind (Desig) = E_Incomplete_Type
and then From_Limited_With (Desig);
end Designates_From_Limited_With;
---------------------------
-- Is_Class_Wide_Default --
---------------------------
function Is_Class_Wide_Default (D : Node_Id) return Boolean is
begin
return Is_Class_Wide_Type (Designated_Type (Etype (D)))
or else (Nkind (D) = N_Attribute_Reference
and then Attribute_Name (D) = Name_Access
and then Is_Class_Wide_Type (Etype (Prefix (D))));
end Is_Class_Wide_Default;
-- Local variables
Context : constant Node_Id := Parent (Parent (T));
Default : Node_Id;
Formal : Entity_Id;
Formal_Type : Entity_Id;
Param_Spec : Node_Id;
Ptype : Entity_Id;
Num_Out_Params : Nat := 0;
First_Out_Param : Entity_Id := Empty;
-- Used for setting Is_Only_Out_Parameter
-- Start of processing for Process_Formals
begin
-- In order to prevent premature use of the formals in the same formal
-- part, the Ekind is left undefined until all default expressions are
-- analyzed. The Ekind is established in a separate loop at the end.
Param_Spec := First (T);
while Present (Param_Spec) loop
Formal := Defining_Identifier (Param_Spec);
Set_Never_Set_In_Source (Formal, True);
Enter_Name (Formal);
-- Case of ordinary parameters
if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
Find_Type (Parameter_Type (Param_Spec));
Ptype := Parameter_Type (Param_Spec);
if Ptype = Error then
goto Continue;
end if;
-- Protect against malformed parameter types
if Nkind (Ptype) not in N_Has_Entity then
Formal_Type := Any_Type;
else
Formal_Type := Entity (Ptype);
end if;
if Is_Incomplete_Type (Formal_Type)
or else
(Is_Class_Wide_Type (Formal_Type)
and then Is_Incomplete_Type (Root_Type (Formal_Type)))
then
-- Ada 2005 (AI-326): Tagged incomplete types allowed in
-- primitive operations, as long as their completion is
-- in the same declarative part. If in the private part
-- this means that the type cannot be a Taft-amendment type.
-- Check is done on package exit. For access to subprograms,
-- the use is legal for Taft-amendment types.
-- Ada 2012: tagged incomplete types are allowed as generic
-- formal types. They do not introduce dependencies and the
-- corresponding generic subprogram does not have a delayed
-- freeze, because it does not need a freeze node. However,
-- it is still the case that untagged incomplete types cannot
-- be Taft-amendment types and must be completed in private
-- part, so the subprogram must appear in the list of private
-- dependents of the type.
if Is_Tagged_Type (Formal_Type)
or else (Ada_Version >= Ada_2012
and then not From_Limited_With (Formal_Type)
and then not Is_Generic_Type (Formal_Type))
then
if Ekind (Scope (Current_Scope)) = E_Package
and then not Is_Generic_Type (Formal_Type)
and then not Is_Class_Wide_Type (Formal_Type)
then
if Nkind (Parent (T)) not in
N_Access_Function_Definition |
N_Access_Procedure_Definition
then
Append_Elmt (Current_Scope,
Private_Dependents (Base_Type (Formal_Type)));
-- Freezing is delayed to ensure that Register_Prim
-- will get called for this operation, which is needed
-- in cases where static dispatch tables aren't built.
-- (Note that the same is done for controlling access
-- parameter cases in function Access_Definition.)
if not Is_Thunk (Current_Scope) then
Set_Has_Delayed_Freeze (Current_Scope);
end if;
end if;
end if;
elsif Nkind (Parent (T)) not in N_Access_Function_Definition
| N_Access_Procedure_Definition
then
-- AI05-0151: Tagged incomplete types are allowed in all
-- formal parts. Untagged incomplete types are not allowed
-- in bodies. Limited views of either kind are not allowed
-- if there is no place at which the non-limited view can
-- become available.
-- Incomplete formal untagged types are not allowed in
-- subprogram bodies (but are legal in their declarations).
-- This excludes bodies created for null procedures, which
-- are basic declarations.
if Is_Generic_Type (Formal_Type)
and then not Is_Tagged_Type (Formal_Type)
and then Nkind (Parent (Related_Nod)) = N_Subprogram_Body
then
Error_Msg_N
("invalid use of formal incomplete type", Param_Spec);
elsif Ada_Version >= Ada_2012 then
if Is_Tagged_Type (Formal_Type)
and then (not From_Limited_With (Formal_Type)
or else not In_Package_Body)
then
null;
elsif Nkind (Context) in N_Accept_Statement
| N_Accept_Alternative
| N_Entry_Body
or else (Nkind (Context) = N_Subprogram_Body
and then Comes_From_Source (Context))
then
Error_Msg_NE
("invalid use of untagged incomplete type &",
Ptype, Formal_Type);
end if;
else
Error_Msg_NE
("invalid use of incomplete type&",
Param_Spec, Formal_Type);
-- Further checks on the legality of incomplete types
-- in formal parts are delayed until the freeze point
-- of the enclosing subprogram or access to subprogram.
end if;
end if;
elsif Ekind (Formal_Type) = E_Void then
Error_Msg_NE
("premature use of&",
Parameter_Type (Param_Spec), Formal_Type);
end if;
-- Ada 2012 (AI-142): Handle aliased parameters
if Ada_Version >= Ada_2012
and then Aliased_Present (Param_Spec)
then
Set_Is_Aliased (Formal);
-- AI12-001: All aliased objects are considered to be specified
-- as independently addressable (RM C.6(8.1/4)).
Set_Is_Independent (Formal);
end if;
-- Ada 2005 (AI-231): Create and decorate an internal subtype
-- declaration corresponding to the null-excluding type of the
-- formal in the enclosing scope. Finally, replace the parameter
-- type of the formal with the internal subtype.
if Ada_Version >= Ada_2005
and then Null_Exclusion_Present (Param_Spec)
then
if not Is_Access_Type (Formal_Type) then
Error_Msg_N
("`NOT NULL` allowed only for an access type", Param_Spec);
else
if Can_Never_Be_Null (Formal_Type)
and then Comes_From_Source (Related_Nod)
then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)",
Param_Spec, Formal_Type);
end if;
Formal_Type :=
Create_Null_Excluding_Itype
(T => Formal_Type,
Related_Nod => Related_Nod,
Scope_Id => Scope (Current_Scope));
-- If the designated type of the itype is an itype that is
-- not frozen yet, we set the Has_Delayed_Freeze attribute
-- on the access subtype, to prevent order-of-elaboration
-- issues in the backend.
-- Example:
-- type T is access procedure;
-- procedure Op (O : not null T);
if Is_Itype (Directly_Designated_Type (Formal_Type))
and then
not Is_Frozen (Directly_Designated_Type (Formal_Type))
then
Set_Has_Delayed_Freeze (Formal_Type);
end if;
end if;
end if;
-- An access formal type
else
Formal_Type :=
Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
-- No need to continue if we already notified errors
if not Present (Formal_Type) then
return;
end if;
-- Ada 2005 (AI-254)
declare
AD : constant Node_Id :=
Access_To_Subprogram_Definition
(Parameter_Type (Param_Spec));
begin
if Present (AD) and then Protected_Present (AD) then
Formal_Type :=
Replace_Anonymous_Access_To_Protected_Subprogram
(Param_Spec);
end if;
end;
end if;
Set_Etype (Formal, Formal_Type);
-- Deal with default expression if present
Default := Expression (Param_Spec);
if Present (Default) then
if Out_Present (Param_Spec) then
Error_Msg_N
("default initialization only allowed for IN parameters",
Param_Spec);
end if;
-- Do the special preanalysis of the expression (see section on
-- "Handling of Default Expressions" in the spec of package Sem).
Preanalyze_Formal_Expression (Default, Formal_Type);
-- An access to constant cannot be the default for
-- an access parameter that is an access to variable.
if Ekind (Formal_Type) = E_Anonymous_Access_Type
and then not Is_Access_Constant (Formal_Type)
and then Is_Access_Type (Etype (Default))
and then Is_Access_Constant (Etype (Default))
then
Error_Msg_N
("formal that is access to variable cannot be initialized "
& "with an access-to-constant expression", Default);
end if;
-- Check that the designated type of an access parameter's default
-- is not a class-wide type unless the parameter's designated type
-- is also class-wide.
if Ekind (Formal_Type) = E_Anonymous_Access_Type
and then not Designates_From_Limited_With (Formal_Type)
and then Is_Class_Wide_Default (Default)
and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
then
Error_Msg_N
("access to class-wide expression not allowed here", Default);
end if;
-- Check incorrect use of dynamically tagged expressions
if Is_Tagged_Type (Formal_Type) then
Check_Dynamically_Tagged_Expression
(Expr => Default,
Typ => Formal_Type,
Related_Nod => Default);
end if;
end if;
-- Ada 2005 (AI-231): Static checks
if Ada_Version >= Ada_2005
and then Is_Access_Type (Etype (Formal))
and then Can_Never_Be_Null (Etype (Formal))
then
Null_Exclusion_Static_Checks (Param_Spec);
end if;
-- The following checks are relevant only when SPARK_Mode is on as
-- these are not standard Ada legality rules.
if SPARK_Mode = On then
if Ekind (Scope (Formal)) in E_Function | E_Generic_Function then
-- A function cannot have a parameter of mode IN OUT or OUT
-- (SPARK RM 6.1).
if Ekind (Formal) in E_In_Out_Parameter | E_Out_Parameter then
Error_Msg_N
("function cannot have parameter of mode `OUT` or "
& "`IN OUT`", Formal);
end if;
-- A procedure cannot have an effectively volatile formal
-- parameter of mode IN because it behaves as a constant
-- (SPARK RM 7.1.3(4)).
elsif Ekind (Scope (Formal)) = E_Procedure
and then Ekind (Formal) = E_In_Parameter
and then Is_Effectively_Volatile (Formal)
then
Error_Msg_N
("formal parameter of mode `IN` cannot be volatile", Formal);
end if;
end if;
-- Deal with aspects on formal parameters. Only Unreferenced is
-- supported for the time being.
if Has_Aspects (Param_Spec) then
declare
Aspect : Node_Id := First (Aspect_Specifications (Param_Spec));
begin
while Present (Aspect) loop
if Chars (Identifier (Aspect)) = Name_Unreferenced then
Set_Has_Pragma_Unreferenced (Formal);
else
Error_Msg_NE
("unsupported aspect& on parameter",
Aspect, Identifier (Aspect));
end if;
Next (Aspect);
end loop;
end;
end if;
<<Continue>>
Next (Param_Spec);
end loop;
-- If this is the formal part of a function specification, analyze the
-- subtype mark in the context where the formals are visible but not
-- yet usable, and may hide outer homographs.
if Nkind (Related_Nod) = N_Function_Specification then
Analyze_Return_Type (Related_Nod);
end if;
-- Now set the kind (mode) of each formal
Param_Spec := First (T);
while Present (Param_Spec) loop
Formal := Defining_Identifier (Param_Spec);
Set_Formal_Mode (Formal);
if Ekind (Formal) = E_In_Parameter then
Set_Default_Value (Formal, Expression (Param_Spec));
if Present (Expression (Param_Spec)) then
Default := Expression (Param_Spec);
if Is_Scalar_Type (Etype (Default)) then
if Nkind (Parameter_Type (Param_Spec)) /=
N_Access_Definition
then
Formal_Type := Entity (Parameter_Type (Param_Spec));
else
Formal_Type :=
Access_Definition
(Related_Nod, Parameter_Type (Param_Spec));
end if;
Apply_Scalar_Range_Check (Default, Formal_Type);
end if;
end if;
elsif Ekind (Formal) = E_Out_Parameter then
Num_Out_Params := Num_Out_Params + 1;
if Num_Out_Params = 1 then
First_Out_Param := Formal;
end if;
elsif Ekind (Formal) = E_In_Out_Parameter then
Num_Out_Params := Num_Out_Params + 1;
end if;
-- Skip remaining processing if formal type was in error
if Etype (Formal) = Any_Type or else Error_Posted (Formal) then
goto Next_Parameter;
end if;
-- Force call by reference if aliased
declare
Conv : constant Convention_Id := Convention (Etype (Formal));
begin
if Is_Aliased (Formal) then
Set_Mechanism (Formal, By_Reference);
-- Warn if user asked this to be passed by copy
if Conv = Convention_Ada_Pass_By_Copy then
Error_Msg_N
("cannot pass aliased parameter & by copy??", Formal);
end if;
-- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy
elsif Conv = Convention_Ada_Pass_By_Copy then
Set_Mechanism (Formal, By_Copy);
elsif Conv = Convention_Ada_Pass_By_Reference then
Set_Mechanism (Formal, By_Reference);
end if;
end;
<<Next_Parameter>>
Next (Param_Spec);
end loop;
if Present (First_Out_Param) and then Num_Out_Params = 1 then
Set_Is_Only_Out_Parameter (First_Out_Param);
end if;
end Process_Formals;
----------------------------
-- Reference_Body_Formals --
----------------------------
procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is
Fs : Entity_Id;
Fb : Entity_Id;
begin
if Error_Posted (Spec) then
return;
end if;
-- Iterate over both lists. They may be of different lengths if the two
-- specs are not conformant.
Fs := First_Formal (Spec);
Fb := First_Formal (Bod);
while Present (Fs) and then Present (Fb) loop
Generate_Reference (Fs, Fb, 'b');
if Style_Check then
Style.Check_Identifier (Fb, Fs);
end if;
Set_Spec_Entity (Fb, Fs);
Set_Referenced (Fs, False);
Next_Formal (Fs);
Next_Formal (Fb);
end loop;
end Reference_Body_Formals;
-------------------------
-- Set_Actual_Subtypes --
-------------------------
procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
Decl : Node_Id;
Formal : Entity_Id;
T : Entity_Id;
First_Stmt : Node_Id := Empty;
AS_Needed : Boolean;
begin
-- If this is an empty initialization procedure, no need to create
-- actual subtypes (small optimization).
if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then
return;
-- Within a predicate function we do not want to generate local
-- subtypes that may generate nested predicate functions.
elsif Is_Subprogram (Subp) and then Is_Predicate_Function (Subp) then
return;
end if;
-- The subtype declarations may freeze the formals. The body generated
-- for an expression function is not a freeze point, so do not emit
-- these declarations (small loss of efficiency in rare cases).
if Nkind (N) = N_Subprogram_Body
and then Was_Expression_Function (N)
then
return;
end if;
Formal := First_Formal (Subp);
while Present (Formal) loop
T := Etype (Formal);
-- We never need an actual subtype for a constrained formal
if Is_Constrained (T) then
AS_Needed := False;
-- If we have unknown discriminants, then we do not need an actual
-- subtype, or more accurately we cannot figure it out. Note that
-- all class-wide types have unknown discriminants.
elsif Has_Unknown_Discriminants (T) then
AS_Needed := False;
-- At this stage we have an unconstrained type that may need an
-- actual subtype. For sure the actual subtype is needed if we have
-- an unconstrained array type. However, in an instance, the type
-- may appear as a subtype of the full view, while the actual is
-- in fact private (in which case no actual subtype is needed) so
-- check the kind of the base type.
elsif Is_Array_Type (Base_Type (T)) then
AS_Needed := True;
-- The only other case needing an actual subtype is an unconstrained
-- record type which is an IN parameter (we cannot generate actual
-- subtypes for the OUT or IN OUT case, since an assignment can
-- change the discriminant values. However we exclude the case of
-- initialization procedures, since discriminants are handled very
-- specially in this context, see the section entitled "Handling of
-- Discriminants" in Einfo.
-- We also exclude the case of Discrim_SO_Functions (functions used
-- in front-end layout mode for size/offset values), since in such
-- functions only discriminants are referenced, and not only are such
-- subtypes not needed, but they cannot always be generated, because
-- of order of elaboration issues.
elsif Is_Record_Type (T)
and then Ekind (Formal) = E_In_Parameter
and then Chars (Formal) /= Name_uInit
and then not Is_Unchecked_Union (T)
and then not Is_Discrim_SO_Function (Subp)
then
AS_Needed := True;
-- All other cases do not need an actual subtype
else
AS_Needed := False;
end if;
-- Generate actual subtypes for unconstrained arrays and
-- unconstrained discriminated records.
if AS_Needed then
if Nkind (N) = N_Accept_Statement then
-- If expansion is active, the formal is replaced by a local
-- variable that renames the corresponding entry of the
-- parameter block, and it is this local variable that may
-- require an actual subtype.
if Expander_Active then
Decl := Build_Actual_Subtype (T, Renamed_Object (Formal));
else
Decl := Build_Actual_Subtype (T, Formal);
end if;
if Present (Handled_Statement_Sequence (N)) then
First_Stmt :=
First (Statements (Handled_Statement_Sequence (N)));
Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
Mark_Rewrite_Insertion (Decl);
else
-- If the accept statement has no body, there will be no
-- reference to the actuals, so no need to compute actual
-- subtypes.
return;
end if;
else
Decl := Build_Actual_Subtype (T, Formal);
Prepend (Decl, Declarations (N));
Mark_Rewrite_Insertion (Decl);
end if;
-- The declaration uses the bounds of an existing object, and
-- therefore needs no constraint checks.
Analyze (Decl, Suppress => All_Checks);
Set_Is_Actual_Subtype (Defining_Identifier (Decl));
-- We need to freeze manually the generated type when it is
-- inserted anywhere else than in a declarative part.
if Present (First_Stmt) then
Insert_List_Before_And_Analyze (First_Stmt,
Freeze_Entity (Defining_Identifier (Decl), N));
-- Ditto if the type has a dynamic predicate, because the
-- generated function will mention the actual subtype. The
-- predicate may come from an explicit aspect of be inherited.
elsif Has_Predicates (T) then
Insert_List_After_And_Analyze (Decl,
Freeze_Entity (Defining_Identifier (Decl), N));
end if;
if Nkind (N) = N_Accept_Statement
and then Expander_Active
then
Set_Actual_Subtype (Renamed_Object (Formal),
Defining_Identifier (Decl));
else
Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
end if;
end if;
Next_Formal (Formal);
end loop;
end Set_Actual_Subtypes;
---------------------
-- Set_Formal_Mode --
---------------------
procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
Spec : constant Node_Id := Parent (Formal_Id);
Id : constant Entity_Id := Scope (Formal_Id);
begin
-- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
-- since we ensure that corresponding actuals are always valid at the
-- point of the call.
if Out_Present (Spec) then
if Is_Entry (Id)
or else Is_Subprogram_Or_Generic_Subprogram (Id)
then
Set_Has_Out_Or_In_Out_Parameter (Id, True);
end if;
if Ekind (Id) in E_Function | E_Generic_Function then
-- [IN] OUT parameters allowed for functions in Ada 2012
if Ada_Version >= Ada_2012 then
-- Even in Ada 2012 operators can only have IN parameters
if Is_Operator_Symbol_Name (Chars (Scope (Formal_Id))) then
Error_Msg_N ("operators can only have IN parameters", Spec);
end if;
if In_Present (Spec) then
Mutate_Ekind (Formal_Id, E_In_Out_Parameter);
else
Mutate_Ekind (Formal_Id, E_Out_Parameter);
end if;
-- But not in earlier versions of Ada
else
Error_Msg_N ("functions can only have IN parameters", Spec);
Mutate_Ekind (Formal_Id, E_In_Parameter);
end if;
elsif In_Present (Spec) then
Mutate_Ekind (Formal_Id, E_In_Out_Parameter);
else
Mutate_Ekind (Formal_Id, E_Out_Parameter);
Set_Never_Set_In_Source (Formal_Id, True);
Set_Is_True_Constant (Formal_Id, False);
Set_Current_Value (Formal_Id, Empty);
end if;
else
Mutate_Ekind (Formal_Id, E_In_Parameter);
end if;
-- Set Is_Known_Non_Null for access parameters since the language
-- guarantees that access parameters are always non-null. We also set
-- Can_Never_Be_Null, since there is no way to change the value.
if Nkind (Parameter_Type (Spec)) = N_Access_Definition then
-- Ada 2005 (AI-231): In Ada 95, access parameters are always non-
-- null; In Ada 2005, only if then null_exclusion is explicit.
if Ada_Version < Ada_2005
or else Can_Never_Be_Null (Etype (Formal_Id))
then
Set_Is_Known_Non_Null (Formal_Id);
Set_Can_Never_Be_Null (Formal_Id);
end if;
-- Ada 2005 (AI-231): Null-exclusion access subtype
elsif Is_Access_Type (Etype (Formal_Id))
and then Can_Never_Be_Null (Etype (Formal_Id))
then
Set_Is_Known_Non_Null (Formal_Id);
-- We can also set Can_Never_Be_Null (thus preventing some junk
-- access checks) for the case of an IN parameter, which cannot
-- be changed, or for an IN OUT parameter, which can be changed but
-- not to a null value. But for an OUT parameter, the initial value
-- passed in can be null, so we can't set this flag in that case.
if Ekind (Formal_Id) /= E_Out_Parameter then
Set_Can_Never_Be_Null (Formal_Id);
end if;
end if;
Set_Mechanism (Formal_Id, Default_Mechanism);
Set_Formal_Validity (Formal_Id);
end Set_Formal_Mode;
-------------------------
-- Set_Formal_Validity --
-------------------------
procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
begin
-- If no validity checking, then we cannot assume anything about the
-- validity of parameters, since we do not know there is any checking
-- of the validity on the call side.
if not Validity_Checks_On then
return;
-- If validity checking for parameters is enabled, this means we are
-- not supposed to make any assumptions about argument values.
elsif Validity_Check_Parameters then
return;
-- If we are checking in parameters, we will assume that the caller is
-- also checking parameters, so we can assume the parameter is valid.
elsif Ekind (Formal_Id) = E_In_Parameter
and then Validity_Check_In_Params
then
Set_Is_Known_Valid (Formal_Id, True);
-- Similar treatment for IN OUT parameters
elsif Ekind (Formal_Id) = E_In_Out_Parameter
and then Validity_Check_In_Out_Params
then
Set_Is_Known_Valid (Formal_Id, True);
end if;
end Set_Formal_Validity;
------------------------
-- Subtype_Conformant --
------------------------
function Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Skip_Controlling_Formals : Boolean := False) return Boolean
is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result,
Skip_Controlling_Formals => Skip_Controlling_Formals);
return Result;
end Subtype_Conformant;
---------------------
-- Type_Conformant --
---------------------
function Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Skip_Controlling_Formals : Boolean := False) return Boolean
is
Result : Boolean;
begin
May_Hide_Profile := False;
Check_Conformance
(New_Id, Old_Id, Type_Conformant, False, Result,
Skip_Controlling_Formals => Skip_Controlling_Formals);
return Result;
end Type_Conformant;
-------------------------------
-- Valid_Operator_Definition --
-------------------------------
procedure Valid_Operator_Definition (Designator : Entity_Id) is
N : Integer := 0;
F : Entity_Id;
Id : constant Name_Id := Chars (Designator);
N_OK : Boolean;
begin
F := First_Formal (Designator);
while Present (F) loop
N := N + 1;
if Present (Default_Value (F)) then
Error_Msg_N
("default values not allowed for operator parameters",
Parent (F));
-- For function instantiations that are operators, we must check
-- separately that the corresponding generic only has in-parameters.
-- For subprogram declarations this is done in Set_Formal_Mode. Such
-- an error could not arise in earlier versions of the language.
elsif Ekind (F) /= E_In_Parameter then
Error_Msg_N ("operators can only have IN parameters", F);
end if;
Next_Formal (F);
end loop;
-- Verify that user-defined operators have proper number of arguments
-- First case of operators which can only be unary
if Id in Name_Op_Not | Name_Op_Abs then
N_OK := (N = 1);
-- Case of operators which can be unary or binary
elsif Id in Name_Op_Add | Name_Op_Subtract then
N_OK := (N in 1 .. 2);
-- All other operators can only be binary
else
N_OK := (N = 2);
end if;
if not N_OK then
Error_Msg_N
("incorrect number of arguments for operator", Designator);
end if;
if Id = Name_Op_Ne
and then Base_Type (Etype (Designator)) = Standard_Boolean
and then not Is_Intrinsic_Subprogram (Designator)
then
Error_Msg_N
("explicit definition of inequality not allowed", Designator);
end if;
end Valid_Operator_Definition;
end Sem_Ch6;