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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 6 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, 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 Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Expander; use Expander;
with Exp_Ch6; use Exp_Ch6;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch9; use Exp_Ch9;
with Exp_Dbug; use Exp_Dbug;
with Exp_Disp; use Exp_Disp;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Fname; use Fname;
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 Rident; use Rident;
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_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.CN; use Sinfo.CN;
with Snames; use Snames;
with Stringt; use Stringt;
with Style;
with Stylesw; use Stylesw;
with Targparm; use Targparm;
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.
function Can_Override_Operator (Subp : Entity_Id) return Boolean;
-- Returns true if Subp can override a predefined operator.
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_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 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
Designator : constant Entity_Id :=
Analyze_Subprogram_Specification (Specification (N));
Scop : constant Entity_Id := Current_Scope;
begin
-- The abstract subprogram declaration may be subject to pragma Ghost
-- with policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged as
-- ignored Ghost.
Set_Ghost_Mode (N);
Check_SPARK_05_Restriction ("abstract subprogram is not allowed", N);
Generate_Definition (Designator);
Set_Is_Abstract_Subprogram (Designator);
New_Overloaded_Entity (Designator);
Check_Delayed_Subprogram (Designator);
Set_Categorization_From_Scope (Designator, Scop);
-- An abstract subprogram declared within a Ghost region is rendered
-- Ghost (SPARK RM 6.9(2)).
if Comes_From_Source (Designator) and then Ghost_Mode > None then
Set_Is_Ghost_Entity (Designator);
end if;
if Ekind (Scope (Designator)) = 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 (Designator)
and then not Present (Overridden_Operation (Designator))
and then (not Is_Operator_Symbol_Name (Chars (Designator))
or else Scop /= Scope (Etype (First_Formal (Designator))))
then
Error_Msg_N
("abstract subprogram is not dispatching or overriding?r?", N);
end if;
Generate_Reference_To_Formals (Designator);
Check_Eliminated (Designator);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Designator);
end if;
end Analyze_Abstract_Subprogram_Declaration;
---------------------------------
-- Analyze_Expression_Function --
---------------------------------
procedure Analyze_Expression_Function (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
LocX : constant Source_Ptr := Sloc (Expression (N));
Expr : constant Node_Id := Expression (N);
Spec : constant Node_Id := Specification (N);
Def_Id : Entity_Id;
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.
New_Body : Node_Id;
New_Spec : Node_Id;
Ret : Node_Id;
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. Types and defauts in
-- the profile are copies of the spec, but new entities must be created
-- for the unit name and the formals.
New_Spec := New_Copy_Tree (Spec);
Set_Defining_Unit_Name (New_Spec,
Make_Defining_Identifier (Sloc (Defining_Unit_Name (Spec)),
Chars (Defining_Unit_Name (Spec))));
if Present (Parameter_Specifications (New_Spec)) then
declare
Formal_Spec : Node_Id;
Def : Entity_Id;
begin
Formal_Spec := First (Parameter_Specifications (New_Spec));
-- Create a new formal parameter at the same source position
while Present (Formal_Spec) loop
Def := Defining_Identifier (Formal_Spec);
Set_Defining_Identifier (Formal_Spec,
Make_Defining_Identifier (Sloc (Def),
Chars => Chars (Def)));
Next (Formal_Spec);
end loop;
end;
end if;
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);
-- 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, Expression (N));
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)));
-- 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);
-- If the expression function is a completion, the previous declaration
-- must come from source. We know already that appears in the current
-- scope. The entity itself may be internally created if within a body
-- to be inlined.
elsif Present (Prev)
and then Comes_From_Source (Parent (Prev))
and then not Is_Formal_Subprogram (Prev)
then
Set_Has_Completion (Prev, False);
-- An expression function that is a completion freezes the
-- expression. This means freezing the return type, and if it is
-- an access type, freezing its designated type as well.
-- 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.
Freeze_Before (N, Etype (Prev));
if Is_Access_Type (Etype (Prev)) then
Freeze_Before (N, Designated_Type (Etype (Prev)));
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);
-- Correct the parent pointer of the aspect specification list to
-- reference the rewritten node.
if Has_Aspects (N) then
Set_Parent (Aspect_Specifications (N), N);
end if;
-- Propagate any pragmas that apply to the 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
Set_Is_Inlined (Prev);
-- 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));
-- Correct the parent pointer of the aspect specification list to
-- reference the rewritten node.
if Has_Aspects (N) then
Set_Parent (Aspect_Specifications (N), N);
end if;
Analyze (N);
-- Within a generic pre-analyze 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 Inside_A_Generic then
declare
Id : constant Entity_Id := Defining_Entity (N);
begin
Set_Has_Completion (Id);
Push_Scope (Id);
Install_Formals (Id);
Preanalyze_Spec_Expression (Expr, Etype (Id));
End_Scope;
end;
end if;
Set_Is_Inlined (Defining_Entity (N));
-- 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, Defining_Entity (N));
-- 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.
declare
Decls : List_Id := List_Containing (N);
Par : constant Node_Id := Parent (Decls);
Id : constant Entity_Id := Defining_Entity (N);
begin
-- If this is a wrapper created for 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 (Defining_Entity (N))
then
Insert_After (N, New_Body);
else
if Nkind (Par) = N_Package_Specification
and then Decls = Visible_Declarations (Par)
and then Present (Private_Declarations (Par))
and then not Is_Empty_List (Private_Declarations (Par))
then
Decls := Private_Declarations (Par);
end if;
Insert_After (Last (Decls), New_Body);
Push_Scope (Id);
Install_Formals (Id);
-- Preanalyze the expression for name capture, except in an
-- instance, where this has been done during generic analysis,
-- and will be redone when analyzing the body.
declare
Expr : constant Node_Id := Expression (Ret);
begin
Set_Parent (Expr, Ret);
if not In_Instance then
Preanalyze_Spec_Expression (Expr, Etype (Id));
end if;
end;
End_Scope;
end if;
end;
end if;
-- If the return expression is a static constant, we suppress warning
-- messages on unused formals, which in most cases will be noise.
Set_Is_Trivial_Subprogram (Defining_Entity (New_Body),
Is_OK_Static_Expression (Expr));
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_Limited_Return (Expr : Node_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_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_Limited_Return --
--------------------------
procedure Check_Limited_Return (Expr : Node_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_Task_Interface (R_Type)
or else Is_Protected_Interface (R_Type)
or else Is_Synchronized_Interface (R_Type))
then
null;
elsif Is_Limited_Type (R_Type)
and then not Is_Interface (R_Type)
and then Comes_From_Source (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, compatibility warnings disabled
else
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_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));
R_Type_Is_Anon_Access : constant Boolean :=
Ekind_In (R_Type,
E_Anonymous_Access_Subprogram_Type,
E_Anonymous_Access_Protected_Subprogram_Type,
E_Anonymous_Access_Type);
-- True if return type of the function is an anonymous access type
-- Can't we make Is_Anonymous_Access_Type in einfo ???
R_Stm_Type_Is_Anon_Access : constant Boolean :=
Ekind_In (R_Stm_Type,
E_Anonymous_Access_Subprogram_Type,
E_Anonymous_Access_Protected_Subprogram_Type,
E_Anonymous_Access_Type);
-- True if type of the return object is an anonymous access type
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 R_Type_Is_Anon_Access then
if R_Stm_Type_Is_Anon_Access 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 R_Stm_Type_Is_Anon_Access
and then not R_Type_Is_Anon_Access
then
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;
-- 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_In (Expr, 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) /= N_Null
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 (Expr);
end if;
-- RETURN only allowed in SPARK as the last statement in function
if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements
and then
(Nkind (Parent (Parent (N))) /= N_Subprogram_Body
or else Present (Next (N)))
then
Check_SPARK_05_Restriction
("RETURN should be the last statement in function", N);
end if;
else
Check_SPARK_05_Restriction ("extended RETURN is not allowed", N);
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));
Analyze (Obj_Decl);
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 RM 6.5 (5.9/3)
if Has_Aliased then
if Ada_Version < Ada_2012 then
-- Shouldn't this test Warn_On_Ada_2012_Compatibility ???
-- Can it really happen (extended return???)
Error_Msg_N
("aliased only allowed for limited return objects "
& "in Ada 2012??", N);
elsif not Is_Limited_View (R_Type) then
Error_Msg_N
("aliased only allowed for limited return objects", N);
end if;
end if;
end;
end if;
-- Case of Expr present
if Present (Expr)
-- Defend against previous errors
and then Nkind (Expr) /= N_Empty
and then Present (Etype (Expr))
then
-- 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.
Apply_Constraint_Check (Expr, R_Type);
-- 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.
if Ada_Version >= Ada_2005
and then Ekind (R_Type) = E_Anonymous_Access_Type
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;
-- ??? A real run-time accessibility check is needed in cases
-- involving dereferences of access parameters. For now we just
-- check the static cases.
if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L)
and then Is_Limited_View (Etype (Scope_Id))
and then Object_Access_Level (Expr) >
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);
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
Set_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
Set_Ekind (Gen_Id, Ekind (Body_Id));
Set_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));
-- Inherit the "ghostness" of the generic spec. Note that this
-- property is not directly inherited as the body may be subject
-- to a different Ghost assertion policy.
if Is_Ghost_Entity (Gen_Id) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (Body_Id);
-- The Ghost policy in effect at the point of declaration and at
-- the point of completion must match (SPARK RM 6.9(15)).
Check_Ghost_Completion (Gen_Id, Body_Id);
end if;
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
Set_Ekind (Gen_Id, Kind);
Set_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, True);
Analyze_Declarations (Declarations (N));
Check_Completion;
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);
End_Scope;
Check_Subprogram_Order (N);
-- Outside of its body, unit is generic again
Set_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 --
----------------------------
procedure Analyze_Null_Procedure
(N : Node_Id;
Is_Completion : out Boolean)
is
Loc : constant Source_Ptr := Sloc (N);
Spec : constant Node_Id := Specification (N);
Designator : Entity_Id;
Form : Node_Id;
Null_Body : Node_Id := Empty;
Prev : Entity_Id;
begin
-- 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.
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 (Make_Null_Statement (Loc))));
-- 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.
Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
if Present (Prev) and then Is_Generic_Subprogram (Prev) then
Insert_Before (N, Null_Body);
Set_Ekind (Defining_Entity (N), Ekind (Prev));
Rewrite (N, Make_Null_Statement (Loc));
Analyze_Generic_Subprogram_Body (Null_Body, Prev);
Is_Completion := True;
return;
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)));
else
-- 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.
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;
Is_Completion := True;
Rewrite (N, Null_Body);
Analyze (N);
end if;
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, and pragma arguments.
procedure Analyze_Operator_Symbol (N : Node_Id) is
Par : constant Node_Id := Parent (N);
begin
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)
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 --
----------------------------
procedure Analyze_Procedure_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
P : constant Node_Id := Name (N);
Actuals : constant List_Id := Parameter_Associations (N);
Actual : Node_Id;
New_N : Node_Id;
procedure Analyze_Call_And_Resolve;
-- Do Analyze and Resolve calls for procedure call
-- At end, check illegal order dependence.
------------------------------
-- 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;
-- 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.
Analyze (P);
-- 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;
end if;
-- 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.
if Error_Posted (N) or else Etype (Name (N)) = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- The name of the procedure call may reference an entity subject to
-- pragma Ghost with policy Ignore. Set the mode now to ensure that any
-- nodes generated during analysis and expansion are properly flagged as
-- ignored Ghost.
Set_Ghost_Mode (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 Nam_In (Attribute_Name (P), 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));
return;
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
return;
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);
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_In (Entity (Selector_Name (P)), E_Entry,
E_Procedure,
E_Function)
then
Analyze_Call_And_Resolve;
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);
end if;
end Analyze_Procedure_Call;
------------------------------
-- Analyze_Return_Statement --
------------------------------
procedure Analyze_Return_Statement (N : Node_Id) is
pragma Assert (Nkind_In (N, N_Simple_Return_Statement,
N_Extended_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, loops,
-- and postconditions.
for J in reverse 0 .. Scope_Stack.Last loop
Result := Scope_Stack.Table (J).Entity;
exit when not Ekind_In (Result, E_Block, E_Loop)
and then Chars (Result) /= Name_uPostconditions;
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 Comes_From_Source (N) then
Error_Msg_N ("RETURN statement not allowed (No_Return)", 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 = E_Function or else Kind = E_Generic_Function then
if not Returns_Object then
Error_Msg_N ("missing expression in return from function", N);
end if;
elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
if Returns_Object then
Error_Msg_N ("procedure cannot return value (use function)", N);
end if;
elsif Kind = E_Entry or else Kind = 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 Ekind_In (Kind, E_Function, E_Generic_Function) then
Analyze_Function_Return (N);
elsif Ekind_In (Kind, 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_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
Check_SPARK_05_Restriction
("access result is not allowed", Result_Definition (N));
-- 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);
-- Unconstrained array as result is not allowed in SPARK
if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then
Check_SPARK_05_Restriction
("returning an unconstrained array is not allowed",
Result_Definition (N));
end if;
-- 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
and then Is_Value_Type (Typ)
then
null;
elsif 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_In (Parent (Parent (N)), 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_Contract --
--------------------------------------
procedure Analyze_Subprogram_Body_Contract (Body_Id : Entity_Id) is
Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
procedure Analyze_Completion_Contract (Spec_Id : Entity_Id);
-- Analyze all delayed pragmas chained on the contract of subprogram
-- body Body_Id as if they appeared at the end of a declarative region.
-- Spec_Id denotes the corresponding spec. The aspects in question are:
-- Refined_Depends
-- Refined_Global
-- Note that pragma Refined_Post is analyzed immediately
---------------------------------
-- Analyze_Completion_Contract --
---------------------------------
procedure Analyze_Completion_Contract (Spec_Id : Entity_Id) is
Items : constant Node_Id := Contract (Body_Id);
Prag : Node_Id;
Prag_Nam : Name_Id;
Ref_Depends : Node_Id := Empty;
Ref_Global : Node_Id := Empty;
begin
-- All subprograms carry a contract, but for some it is not
-- significant and should not be processed.
if not Has_Significant_Contract (Spec_Id) then
return;
elsif Present (Items) then
-- Locate and store pragmas Refined_Depends and Refined_Global
-- since their order of analysis matters.
Prag := Classifications (Items);
while Present (Prag) loop
Prag_Nam := Pragma_Name (Prag);
if Prag_Nam = Name_Refined_Depends then
Ref_Depends := Prag;
elsif Prag_Nam = Name_Refined_Global then
Ref_Global := Prag;
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
-- Analyze Refined_Global first as Refined_Depends may mention items
-- classified in the global refinement.
if Present (Ref_Global) then
Analyze_Refined_Global_In_Decl_Part (Ref_Global);
end if;
-- Refined_Depends must be analyzed after Refined_Global in order to
-- see the modes of all global refinements.
if Present (Ref_Depends) then
Analyze_Refined_Depends_In_Decl_Part (Ref_Depends);
end if;
end Analyze_Completion_Contract;
-- Local variables
Mode : SPARK_Mode_Type;
Spec_Id : Entity_Id;
-- Start of processing for Analyze_Subprogram_Body_Contract
begin
-- When a subprogram body declaration is illegal, its defining entity is
-- left unanalyzed. There is nothing left to do in this case because the
-- body lacks a contract, or even a proper Ekind.
if Ekind (Body_Id) = E_Void then
return;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related subprogram body.
Save_SPARK_Mode_And_Set (Body_Id, Mode);
if Nkind (Body_Decl) = N_Subprogram_Body_Stub then
Spec_Id := Corresponding_Spec_Of_Stub (Body_Decl);
else
Spec_Id := Corresponding_Spec (Body_Decl);
end if;
-- The subprogram body is a completion, analyze all delayed pragmas that
-- apply. Note that when the body is stand alone, the pragmas are always
-- analyzed on the spot.
if Present (Spec_Id) then
Analyze_Completion_Contract (Spec_Id);
end if;
-- Ensure that the contract cases or postconditions mention 'Result or
-- define a post-state.
Check_Result_And_Post_State (Body_Id);
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Mode);
end Analyze_Subprogram_Body_Contract;
------------------------------------
-- 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.
procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Body_Spec : constant Node_Id := Specification (N);
Body_Id : Entity_Id := Defining_Entity (Body_Spec);
Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
Conformant : Boolean;
HSS : Node_Id;
Prot_Typ : Entity_Id := Empty;
Spec_Id : Entity_Id;
Spec_Decl : Node_Id := Empty;
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.
procedure Analyze_Aspects_On_Body_Or_Stub;
-- Analyze the aspect specifications of a subprogram body [stub]. It is
-- assumed that N has aspects.
function Body_Has_Contract return Boolean;
-- Check whether unanalyzed body has an aspect or pragma that may
-- generate a SPARK contract.
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.
procedure Exchange_Limited_Views (Subp_Id : Entity_Id);
-- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains
-- incomplete types coming from a limited context and swap their limited
-- views with the non-limited ones.
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.
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 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.
-------------------------------------
-- Analyze_Aspects_On_Body_Or_Stub --
-------------------------------------
procedure Analyze_Aspects_On_Body_Or_Stub is
procedure Diagnose_Misplaced_Aspects;
-- Subprogram body [stub] N has aspects, but they are not properly
-- placed. Provide precise diagnostics depending on the aspects
-- involved.
--------------------------------
-- Diagnose_Misplaced_Aspects --
--------------------------------
procedure Diagnose_Misplaced_Aspects is
Asp : Node_Id;
Asp_Nam : Name_Id;
Asp_Id : Aspect_Id;
-- The current aspect along with its name and id
procedure SPARK_Aspect_Error (Ref_Nam : Name_Id);
-- Emit an error message concerning SPARK aspect Asp. Ref_Nam is
-- the name of the refined version of the aspect.
------------------------
-- SPARK_Aspect_Error --
------------------------
procedure SPARK_Aspect_Error (Ref_Nam : Name_Id) is
begin
-- The corresponding spec already contains the aspect in
-- question and the one appearing on the body must be the
-- refined form:
-- procedure P with Global ...;
-- procedure P with Global ... is ... end P;
-- ^
-- Refined_Global
if Has_Aspect (Spec_Id, Asp_Id) then
Error_Msg_Name_1 := Asp_Nam;
-- Subunits cannot carry aspects that apply to a subprogram
-- declaration.
if Nkind (Parent (N)) = N_Subunit then
Error_Msg_N ("aspect % cannot apply to a subunit", Asp);
else
Error_Msg_Name_2 := Ref_Nam;
Error_Msg_N ("aspect % should be %", Asp);
end if;
-- Otherwise the aspect must appear in the spec, not in the
-- body:
-- procedure P;
-- procedure P with Global ... is ... end P;
else
Error_Msg_N
("aspect specification must appear in subprogram "
& "declaration", Asp);
end if;
end SPARK_Aspect_Error;
-- Start of processing for Diagnose_Misplaced_Aspects
begin
-- Iterate over the aspect specifications and emit specific errors
-- where applicable.
Asp := First (Aspect_Specifications (N));
while Present (Asp) loop
Asp_Nam := Chars (Identifier (Asp));
Asp_Id := Get_Aspect_Id (Asp_Nam);
-- Do not emit errors on aspects that can appear on a
-- subprogram body. This scenario occurs when the aspect
-- specification list contains both misplaced and properly
-- placed aspects.
if Aspect_On_Body_Or_Stub_OK (Asp_Id) then
null;
-- Special diagnostics for SPARK aspects
elsif Asp_Nam = Name_Depends then
SPARK_Aspect_Error (Name_Refined_Depends);
elsif Asp_Nam = Name_Global then
SPARK_Aspect_Error (Name_Refined_Global);
elsif Asp_Nam = Name_Post then
SPARK_Aspect_Error (Name_Refined_Post);
else
Error_Msg_N
("aspect specification must appear in subprogram "
& "declaration", Asp);
end if;
Next (Asp);
end loop;
end Diagnose_Misplaced_Aspects;
-- Start of processing for Analyze_Aspects_On_Body_Or_Stub
begin
-- Language-defined aspects cannot be associated with a subprogram
-- body [stub] if the subprogram has a spec. Certain implementation
-- defined aspects are allowed to break this rule (for list, see
-- table Aspect_On_Body_Or_Stub_OK).
if Present (Spec_Id) and then not Aspects_On_Body_Or_Stub_OK (N) then
Diagnose_Misplaced_Aspects;
else
Analyze_Aspect_Specifications (N, Body_Id);
end if;
end Analyze_Aspects_On_Body_Or_Stub;
-----------------------
-- Body_Has_Contract --
-----------------------
function Body_Has_Contract return Boolean is
Decls : constant List_Id := Declarations (N);
A_Spec : Node_Id;
A : Aspect_Id;
Decl : Node_Id;
P_Id : Pragma_Id;
begin
-- Check for unanalyzed aspects in the body that will
-- generate a contract.
if Present (Aspect_Specifications (N)) then
A_Spec := First (Aspect_Specifications (N));
while Present (A_Spec) loop
A := Get_Aspect_Id (Chars (Identifier (A_Spec)));
if A = Aspect_Contract_Cases or else
A = Aspect_Depends or else
A = Aspect_Global or else
A = Aspect_Pre or else
A = Aspect_Precondition or else
A = Aspect_Post or else
A = Aspect_Postcondition
then
return True;
end if;
Next (A_Spec);
end loop;
end if;
-- Check for pragmas that may generate a contract
if Present (Decls) then
Decl := First (Decls);
while Present (Decl) loop
if Nkind (Decl) = N_Pragma then
P_Id := Get_Pragma_Id (Pragma_Name (Decl));
if P_Id = Pragma_Contract_Cases or else
P_Id = Pragma_Depends or else
P_Id = Pragma_Global or else
P_Id = Pragma_Pre or else
P_Id = Pragma_Precondition or else
P_Id = Pragma_Post or else
P_Id = Pragma_Postcondition
then
return True;
end if;
end if;
Next (Decl);
end loop;
end if;
return False;
end Body_Has_Contract;
----------------------------
-- 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
-- Avoid cases with no tasking support
and then RTE_Available (RE_Current_Master)
and then not Restriction_Active (No_Task_Hierarchy)
then
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uMaster),
Constant_Present => True,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Master_Id), Loc),
Expression =>
Make_Explicit_Dereference (Loc,
New_Occurrence_Of (RTE (RE_Current_Master), 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_In
(Par, 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
return
Nkind (N) = N_Pragma
and then
(Pragma_Name (N) = Name_Inline_Always
or else (Front_End_Inlining
and then Pragma_Name (N) = Name_Inline))
and then
Chars
(Expression (First (Pragma_Argument_Associations (N)))) =
Chars (Body_Id);
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) then
if Present (Spec_Id) then
if In_Same_List (N, Unit_Declaration_Node (Spec_Id)) then
Analyze (Prag);
end if;
else
-- Create a subprogram declaration, to make treatment uniform
declare
Subp : constant Entity_Id :=
Make_Defining_Identifier (Loc, Chars (Body_Id));
Decl : constant Node_Id :=
Make_Subprogram_Declaration (Loc,
Specification =>
New_Copy_Tree (Specification (N)));
begin
Set_Defining_Unit_Name (Specification (Decl), Subp);
if Present (First_Formal (Body_Id)) then
Plist := Copy_Parameter_List (Body_Id);
Set_Parameter_Specifications
(Specification (Decl), Plist);
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;
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
and then Present (Spec_Id)
and then No_Return (Spec_Id)
then
Check_Returns (HSS, 'P', Missing_Ret, Spec_Id);
end if;
-- Special checks in SPARK mode
if Nkind (Body_Spec) = N_Function_Specification then
-- In SPARK mode, last statement of a function should be a return
declare
Stat : constant Node_Id := Last_Source_Statement (HSS);
begin
if Present (Stat)
and then not Nkind_In (Stat, N_Simple_Return_Statement,
N_Extended_Return_Statement)
then
Check_SPARK_05_Restriction
("last statement in function should be RETURN", Stat);
end if;
end;
-- In SPARK mode, verify that a procedure has no return
elsif Nkind (Body_Spec) = N_Procedure_Specification then
if Present (Spec_Id) then
Id := Spec_Id;
else
Id := Body_Id;
end if;
-- Would be nice to point to return statement here, can we
-- borrow the Check_Returns procedure here ???
if Return_Present (Id) then
Check_SPARK_05_Restriction
("procedure should not have RETURN", N);
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 --
----------------------------
procedure Exchange_Limited_Views (Subp_Id : Entity_Id) is
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.
-------------------------
-- Detect_And_Exchange --
-------------------------
procedure Detect_And_Exchange (Id : Entity_Id) is
Typ : constant Entity_Id := Etype (Id);
begin
if Ekind (Typ) = E_Incomplete_Type
and then From_Limited_With (Typ)
and then Present (Non_Limited_View (Typ))
then
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
if No (Subp_Id) then
return;
-- Do not process subprogram bodies as they already use the non-
-- limited view of types.
elsif not Ekind_In (Subp_Id, E_Function, E_Procedure) then
return;
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;
end Exchange_Limited_Views;
-------------------------------------
-- 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;
----------------------------
-- 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;
---------------------------------
-- 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;
elsif not Present (Overridden_Operation (Spec_Id)) 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 Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Spec_Id)))
then
pragma Assert (Unit_Declaration_Node (Body_Id) = N);
Style.Missing_Overriding (N, Body_Id);
end if;
end Verify_Overriding_Indicator;
-- Start of processing for Analyze_Subprogram_Body_Helper
begin
-- 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;
-- The corresponding spec may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged
-- as ignored Ghost.
Set_Ghost_Mode (N, 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;
return;
else
-- Previous entity conflicts with subprogram name. Attempting to
-- enter name will post error.
Enter_Name (Body_Id);
return;
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
return;
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;
-- The corresponding spec may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged
-- as ignored Ghost.
Set_Ghost_Mode (N, Spec_Id);
else
Spec_Id := Find_Corresponding_Spec (N);
-- The corresponding spec may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged
-- as ignored Ghost.
Set_Ghost_Mode (N, 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.
if No (Spec_Id) and then GNATprove_Mode
-- Inlining does not apply during pre-analysis 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 frontend 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
then
declare
Body_Spec : constant Node_Id :=
Copy_Separate_Tree (Specification (N));
New_Decl : constant Node_Id :=
Make_Subprogram_Declaration (Loc,
Copy_Separate_Tree (Specification (N)));
SPARK_Mode_Aspect : Node_Id;
Aspects : List_Id;
Prag, Aspect : Node_Id;
begin
Insert_Before (N, New_Decl);
Move_Aspects (From => N, To => New_Decl);
-- Mark the newly moved aspects as not analyzed, so that
-- their effect on New_Decl is properly analyzed.
Aspect := First (Aspect_Specifications (New_Decl));
while Present (Aspect) loop
Set_Analyzed (Aspect, False);
Next (Aspect);
end loop;
Analyze (New_Decl);
-- The analysis of the generated subprogram declaration
-- may have introduced pragmas that need to be analyzed.
Prag := Next (New_Decl);
while Prag /= N loop
Analyze (Prag);
Next (Prag);
end loop;
Spec_Id := Defining_Entity (New_Decl);
-- As Body_Id originally comes from source, mark the new
-- Spec_Id as such, which is required so that calls to
-- this subprogram are registered in the local effects
-- stored in ALI files for GNATprove.
Set_Comes_From_Source (Spec_Id, True);
-- If aspect SPARK_Mode was specified on the body, it
-- needs to be repeated on the generated decl and the
-- body. Since the original aspect was moved to the
-- generated decl, copy it for the body.
if Has_Aspect (Spec_Id, Aspect_SPARK_Mode) then
SPARK_Mode_Aspect :=
New_Copy (Find_Aspect (Spec_Id, Aspect_SPARK_Mode));
Set_Analyzed (SPARK_Mode_Aspect, False);
Aspects := New_List (SPARK_Mode_Aspect);
Set_Aspect_Specifications (N, Aspects);
end if;
Set_Specification (N, Body_Spec);
Body_Id := Analyze_Subprogram_Specification (Body_Spec);
Set_Corresponding_Spec (N, Spec_Id);
end;
end if;
end if;
-- If this is a duplicate body, no point in analyzing it
if Error_Posted (N) then
return;
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);
-- The corresponding spec may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged
-- as ignored Ghost.
Set_Ghost_Mode (N, Spec_Id);
end if;
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 protected 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_Private_Protected_Declaration (N);
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 ASIS mode to enable
-- the proper back-annotations.
if not Is_Frozen (Spec_Id)
and then (Expander_Active or ASIS_Mode)
then
-- Force the generation of its freezing node to ensure proper
-- management of access types in the backend.
-- This is definitely needed for some cases, but it is not clear
-- why, to be investigated further???
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);
return;
else
Set_Convention (Body_Id, Convention (Spec_Id));
Set_Has_Completion (Spec_Id);
-- Inherit the "ghostness" of the subprogram spec. Note that this
-- property is not directly inherited as the body may be subject
-- to a different Ghost assertion policy.
if Is_Ghost_Entity (Spec_Id) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (Body_Id);
-- The Ghost policy in effect at the point of declaration and
-- at the point of completion must match (SPARK RM 6.9(15)).
Check_Ghost_Completion (Spec_Id, Body_Id);
end if;
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.
elsif Comes_From_Source (N)
and then not Comes_From_Source (Spec_Id)
and then Has_Pragma_Inline (Spec_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
return;
end if;
end if;
if Spec_Id /= Body_Id then
Reference_Body_Formals (Spec_Id, Body_Id);
end if;
Set_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 (and indeed we definitely
-- do not want these definitions -gnatc mode, because that would
-- confuse ASIS).
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);
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;
-- Set SPARK_Mode from context
Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Body_Id, True);
-- 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 Comes_From_Source (N) then
declare
Etyp : Entity_Id;
Rtyp : Entity_Id;
begin
Rtyp := Etype (Current_Scope);
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
Set_Directly_Designated_Type
(Etype (Current_Scope), Available_View (Etyp));
end if;
end if;
end;
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);
if Nkind (N) = N_Subprogram_Body_Stub then
-- Analyze any aspect specifications that appear on the subprogram
-- body stub.
if Has_Aspects (N) then
Analyze_Aspects_On_Body_Or_Stub;
end if;
-- Stop the analysis now as the stub cannot be inlined, plus it does
-- not have declarative or statement lists.
return;
end if;
-- Handle frontend inlining
-- Note: Normally we don't do any inlining if expansion is off, since
-- we won't generate code in any case. An exception arises in GNATprove
-- mode where we want to expand some calls in place, even with expansion
-- disabled, since the inlining eases formal verification.
if not GNATprove_Mode
and then 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 frontend inlining)
if not Back_End_Inlining then
if (Has_Pragma_Inline_Always (Spec_Id)
and then not Opt.Disable_FE_Inline_Always)
or else
(Has_Pragma_Inline (Spec_Id) and then Front_End_Inlining
and then not Opt.Disable_FE_Inline)
then
Build_Body_To_Inline (N, Spec_Id);
end if;
-- New implementation (relying on backend 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 frontend
-- inlining. This inlining should occur after analysis of the body, so
-- that it is known whether the value of SPARK_Mode applicable to the
-- body, which can be defined by a pragma inside the body.
elsif GNATprove_Mode
and then Full_Analysis
and then not Inside_A_Generic
and then Present (Spec_Id)
and then Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Declaration
and then Can_Be_Inlined_In_GNATprove_Mode (Spec_Id, Body_Id)
and then not Body_Has_Contract
then
Build_Body_To_Inline (N, Spec_Id);
end if;
-- 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;
-- 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 then
Exchange_Limited_Views (Spec_Id);
end if;
-- Analyze any aspect specifications that appear on the subprogram body
if Has_Aspects (N) then
Analyze_Aspects_On_Body_Or_Stub;
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_Pragma (SPARK_Pragma (Spec_Id)) = Off
and then
Get_SPARK_Mode_From_Pragma (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;
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;
-- When a subprogram body appears inside a package, its contract is
-- analyzed at the end of the package body declarations. This is due
-- to the delay with respect of the package contract upon which the
-- body contract may depend. When the subprogram body is stand alone
-- and acts as a compilation unit, this delay is not necessary.
if Nkind (Parent (N)) = N_Compilation_Unit then
Analyze_Subprogram_Body_Contract (Body_Id);
end if;
-- Deal with preconditions, [refined] postconditions, Contract_Cases,
-- invariants and predicates associated with body and its spec. Since
-- there is no routine Expand_Declarations which would otherwise deal
-- with the contract expansion, generate all necessary mechanisms to
-- verify the contract assertions now.
Expand_Subprogram_Contract (N);
-- If SPARK_Mode for body is not On, disable frontend inlining for this
-- subprogram in GNATprove mode, as its body should not be analyzed.
if SPARK_Mode /= On
and then GNATprove_Mode
and then Present (Spec_Id)
and then Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Declaration
then
Set_Body_To_Inline (Parent (Parent (Spec_Id)), Empty);
Set_Is_Inlined_Always (Spec_Id, False);
end if;
-- Check completion, and analyze the statements
Check_Completion;
Inspect_Deferred_Constant_Completion (Declarations (N));
Analyze (HSS);
-- Deal with end of scope processing for the body
Process_End_Label (HSS, 't', Current_Scope);
End_Scope;
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
Set_Next_Entity
(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;
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 initial labels (for one thing this occurs when we are in
-- front end ZCX mode, but in any case it is irrelevant), and also
-- initial Push_xxx_Error_Label nodes, which are also irrelevant.
Stm := First (Statements (HSS));
while Nkind (Stm) = N_Label
or else Nkind (Stm) in 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, 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 in body
Check_References (Body_Id);
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;
end Analyze_Subprogram_Body_Helper;
---------------------------------
-- Analyze_Subprogram_Contract --
---------------------------------
procedure Analyze_Subprogram_Contract (Subp_Id : Entity_Id) is
procedure Save_Global_References_In_List (First_Prag : Node_Id);
-- Save all global references in contract-related source pragma found in
-- the list starting from pragma First_Prag.
------------------------------------
-- Save_Global_References_In_List --
------------------------------------
procedure Save_Global_References_In_List (First_Prag : Node_Id) is
Prag : Node_Id;
begin
Prag := First_Prag;
while Present (Prag) loop
if Comes_From_Source (Prag)
and then Nam_In (Pragma_Name (Prag), Name_Contract_Cases,
Name_Depends,
Name_Extensions_Visible,
Name_Global,
Name_Postcondition,
Name_Precondition,
Name_Test_Case)
then
Save_Global_References (Original_Node (Prag));
end if;
Prag := Next_Pragma (Prag);
end loop;
end Save_Global_References_In_List;
-- Local variables
Items : constant Node_Id := Contract (Subp_Id);
Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id);
Depends : Node_Id := Empty;
Global : Node_Id := Empty;
Mode : SPARK_Mode_Type;
Prag : Node_Id;
Prag_Nam : Name_Id;
Restore_Scope : Boolean := False;
-- Start of processing for Analyze_Subprogram_Contract
begin
-- All subprograms carry a contract, but for some it is not significant
-- and should not be processed.
if not Has_Significant_Contract (Subp_Id) then
return;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related subprogram body.
Save_SPARK_Mode_And_Set (Subp_Id, Mode);
-- Ensure that the formal parameters are visible when analyzing all
-- contract items.
if not In_Open_Scopes (Subp_Id) then
Restore_Scope := True;
Push_Scope (Subp_Id);
if Is_Generic_Subprogram (Subp_Id) then
Install_Generic_Formals (Subp_Id);
else
Install_Formals (Subp_Id);
end if;
end if;
if Present (Items) then
-- Analyze pre- and postconditions
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
Analyze_Pre_Post_Condition_In_Decl_Part (Prag);
Prag := Next_Pragma (Prag);
end loop;
-- Analyze contract-cases and test-cases
Prag := Contract_Test_Cases (Items);
while Present (Prag) loop
Prag_Nam := Pragma_Name (Prag);
if Prag_Nam = Name_Contract_Cases then
Analyze_Contract_Cases_In_Decl_Part (Prag);
else
pragma Assert (Prag_Nam = Name_Test_Case);
Analyze_Test_Case_In_Decl_Part (Prag);
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Analyze classification pragmas
Prag := Classifications (Items);
while Present (Prag) loop
Prag_Nam := Pragma_Name (Prag);
if Prag_Nam = Name_Depends then
Depends := Prag;