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gnu / gcc / 9b1856d6c8c54a1b4b7e3a312f46a76f6d89c3df / . / gcc / ada / sem_ch6.adb
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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 6 --
-- --
-- B o d y --
-- --
-- $Revision$
-- --
-- Copyright (C) 1992-2001, 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
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_Ch7; use Exp_Ch7;
with Fname; use Fname;
with Freeze; use Freeze;
with Lib.Xref; use Lib.Xref;
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 Rtsfind; use Rtsfind;
with Sem; use Sem;
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_Ch12; use Sem_Ch12;
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 Tbuild; use Tbuild;
with Uintp; use Uintp;
with Urealp; use Urealp;
with Validsw; use Validsw;
package body Sem_Ch6 is
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
-- Analyze a generic subprogram body
function Build_Body_To_Inline
(N : Node_Id;
Subp : Entity_Id;
Orig_Body : Node_Id)
return Boolean;
-- If a subprogram has pragma Inline and inlining is active, use generic
-- machinery to build an unexpanded body for the subprogram. This body is
-- subsequenty used for inline expansions at call sites. If subprogram can
-- be inlined (depending on size and nature of local declarations) this
-- function returns true. Otherwise subprogram body is treated normally.
type Conformance_Type is
(Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
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);
-- 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.
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 can happen for primitive operations
-- of types derived (in the generic unit) from formal private or formal
-- derived types.
procedure Check_Returns
(HSS : Node_Id;
Mode : Character;
Err : out Boolean);
-- Called to check for missing return statements in a function body,
-- or for returns present in a procedure body which has No_Return set.
-- L is the handled statement sequence for the subprogram body. This
-- procedure checks all flow paths to make sure they either have a
-- return (Mode = 'F') or do not have a return (Mode = 'P'). 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.
function Conforming_Types
(T1 : Entity_Id;
T2 : Entity_Id;
Ctype : Conformance_Type;
Get_Inst : Boolean := False)
return Boolean;
-- Check that two formal parameter types conform, checking both
-- for equality of base types, and where required statically
-- matching subtypes, depending on the setting of Ctype.
procedure Enter_Overloaded_Entity (S : Entity_Id);
-- This procedure makes S, a new overloaded entity, into the first
-- visible entity with that name.
procedure Install_Entity (E : Entity_Id);
-- Make single entity visible. Used for generic formals as well.
procedure Install_Formals (Id : Entity_Id);
-- On entry to a subprogram body, make the formals visible. Note
-- that simply placing the subprogram on the scope stack is not
-- sufficient: the formals must become the current entities for
-- their names.
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 May_Need_Actuals (Fun : Entity_Id);
-- Flag functions that can be called without parameters, i.e. those that
-- have no parameters, or those for which defaults exist for all parameters
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_Spec (Specification (N));
Scop : constant Entity_Id := Current_Scope;
begin
Generate_Definition (Designator);
Set_Is_Abstract (Designator);
New_Overloaded_Entity (Designator);
Check_Delayed_Subprogram (Designator);
Set_Is_Pure (Designator,
Is_Pure (Scop) and then Is_Library_Level_Entity (Designator));
Set_Is_Remote_Call_Interface (
Designator, Is_Remote_Call_Interface (Scop));
Set_Is_Remote_Types (Designator, Is_Remote_Types (Scop));
if Ekind (Scope (Designator)) = E_Protected_Type then
Error_Msg_N
("abstract subprogram not allowed in protected type", N);
end if;
end Analyze_Abstract_Subprogram_Declaration;
----------------------------
-- Analyze_Function_Call --
----------------------------
procedure Analyze_Function_Call (N : Node_Id) is
P : constant Node_Id := Name (N);
L : constant List_Id := Parameter_Associations (N);
Actual : Node_Id;
begin
Analyze (P);
-- If error analyzing name, then set Any_Type as result type and return
if Etype (P) = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- Otherwise analyze the parameters
if Present (L) then
Actual := First (L);
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
Next (Actual);
end loop;
end if;
Analyze_Call (N);
end Analyze_Function_Call;
-------------------------------------
-- 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);
Spec : Node_Id;
Kind : constant Entity_Kind := Ekind (Gen_Id);
Nam : Entity_Id;
New_N : 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.
Nam := Defining_Entity (Spec);
if Kind = E_Generic_Procedure
and then Nkind (Spec) /= N_Procedure_Specification
then
Error_Msg_N ("invalid body for generic procedure ", Nam);
return;
elsif Kind = E_Generic_Function
and then Nkind (Spec) /= N_Function_Specification
then
Error_Msg_N ("invalid body for generic function ", Nam);
return;
end if;
Set_Corresponding_Body (Gen_Decl, Nam);
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.
New_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.
Nam := Analyze_Spec (Spec);
if Nkind (N) = N_Subprogram_Body_Stub then
-- Nothing to do if no body to process
Set_Ekind (Nam, Kind);
End_Scope;
return;
end if;
if Present (E) then
-- E is the first formal parameter, which must be the first
-- entity in the subprogram body.
Set_First_Entity (Gen_Id, E);
-- Now make formal parameters visible
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 (Nam));
Set_Convention (Nam, Convention (Gen_Id));
Set_Scope (Nam, Scope (Gen_Id));
Check_Fully_Conformant (Nam, Gen_Id, Nam);
-- 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);
Set_Actual_Subtypes (N, Current_Scope);
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;
end;
End_Scope;
Check_Subprogram_Order (N);
-- Outside of its body, unit is generic again.
Set_Ekind (Gen_Id, Kind);
Set_Ekind (Nam, E_Subprogram_Body);
Generate_Reference (Gen_Id, Nam, 'b');
Style.Check_Identifier (Nam, Gen_Id);
End_Generic;
end Analyze_Generic_Subprogram_Body;
-----------------------------
-- 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 a
-- 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
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 defererence)
-- 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 error analyzing prefix, then set Any_Type as result and return
if Etype (P) = 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;
-- Special processing for Elab_Spec and Elab_Body calls
if Nkind (P) = N_Attribute_Reference
and then (Attribute_Name (P) = Name_Elab_Spec
or else Attribute_Name (P) = Name_Elab_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 (Entity (Selector_Name (P))) = E_Entry
or else
Ekind (Entity (Selector_Name (P))) = E_Procedure
or else
Ekind (Entity (Selector_Name (P))) = 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;
-- 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
Loc : constant Source_Ptr := Sloc (N);
Expr : Node_Id;
Scope_Id : Entity_Id;
Kind : Entity_Kind;
R_Type : Entity_Id;
begin
-- Find subprogram or accept statement enclosing the return statement
Scope_Id := Empty;
for J in reverse 0 .. Scope_Stack.Last loop
Scope_Id := Scope_Stack.Table (J).Entity;
exit when Ekind (Scope_Id) /= E_Block and then
Ekind (Scope_Id) /= E_Loop;
end loop;
pragma Assert (Present (Scope_Id));
Kind := Ekind (Scope_Id);
Expr := Expression (N);
if Kind /= E_Function
and then Kind /= E_Generic_Function
and then Kind /= E_Procedure
and then Kind /= E_Generic_Procedure
and then Kind /= E_Entry
and then Kind /= E_Entry_Family
then
Error_Msg_N ("illegal context for return statement", N);
elsif Present (Expr) then
if Kind = E_Function or else Kind = E_Generic_Function then
Set_Return_Present (Scope_Id);
R_Type := Etype (Scope_Id);
Set_Return_Type (N, R_Type);
Analyze_And_Resolve (Expr, R_Type);
if (Is_Class_Wide_Type (Etype (Expr))
or else Is_Dynamically_Tagged (Expr))
and then not Is_Class_Wide_Type (R_Type)
then
Error_Msg_N
("dynamically tagged expression not allowed!", Expr);
end if;
Apply_Constraint_Check (Expr, R_Type);
-- ??? A real run-time accessibility check is needed
-- in cases involving dereferences of access parameters.
-- For now we just check the static cases.
if Is_Return_By_Reference_Type (Etype (Scope_Id))
and then Object_Access_Level (Expr)
> Subprogram_Access_Level (Scope_Id)
then
Rewrite (N, Make_Raise_Program_Error (Loc));
Analyze (N);
Error_Msg_N
("cannot return a local value by reference?", N);
Error_Msg_NE
("& will be raised at run time?!",
N, Standard_Program_Error);
end if;
elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
Error_Msg_N ("procedure cannot return value (use function)", N);
else
Error_Msg_N ("accept statement cannot return value", N);
end if;
-- No expression present
else
if Kind = E_Function or Kind = E_Generic_Function then
Error_Msg_N ("missing expression in return from function", N);
end if;
if (Ekind (Scope_Id) = E_Procedure
or else Ekind (Scope_Id) = E_Generic_Procedure)
and then No_Return (Scope_Id)
then
Error_Msg_N
("RETURN statement not allowed (No_Return)", N);
end if;
end if;
Check_Unreachable_Code (N);
end Analyze_Return_Statement;
------------------
-- Analyze_Spec --
------------------
function Analyze_Spec (N : Node_Id) return Entity_Id is
Designator : constant Entity_Id := Defining_Entity (N);
Formals : constant List_Id := Parameter_Specifications (N);
Typ : Entity_Id;
begin
Generate_Definition (Designator);
if Nkind (N) = N_Function_Specification then
Set_Ekind (Designator, E_Function);
Set_Mechanism (Designator, Default_Mechanism);
if Subtype_Mark (N) /= Error then
Find_Type (Subtype_Mark (N));
Typ := Entity (Subtype_Mark (N));
Set_Etype (Designator, Typ);
if (Ekind (Typ) = E_Incomplete_Type
or else (Is_Class_Wide_Type (Typ)
and then
Ekind (Root_Type (Typ)) = E_Incomplete_Type))
then
Error_Msg_N
("invalid use of incomplete type", Subtype_Mark (N));
end if;
else
Set_Etype (Designator, Any_Type);
end if;
else
Set_Ekind (Designator, E_Procedure);
Set_Etype (Designator, Standard_Void_Type);
end if;
if Present (Formals) then
Set_Scope (Designator, Current_Scope);
New_Scope (Designator);
Process_Formals (Designator, Formals, N);
End_Scope;
end if;
if Nkind (N) = N_Function_Specification then
if Nkind (Designator) = N_Defining_Operator_Symbol then
Valid_Operator_Definition (Designator);
end if;
May_Need_Actuals (Designator);
if Is_Abstract (Etype (Designator))
and then Nkind (Parent (N)) /= N_Abstract_Subprogram_Declaration
then
Error_Msg_N
("function that returns abstract type must be abstract", N);
end if;
end if;
return Designator;
end Analyze_Spec;
-----------------------------
-- Analyze_Subprogram_Body --
-----------------------------
-- 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 (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);
HSS : Node_Id;
Spec_Id : Entity_Id;
Spec_Decl : Node_Id := Empty;
Last_Formal : Entity_Id := Empty;
Conformant : Boolean;
Missing_Ret : Boolean;
Body_Deleted : Boolean := False;
begin
if Debug_Flag_C then
Write_Str ("==== Compiling subprogram body ");
Write_Name (Chars (Body_Id));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
end if;
Trace_Scope (N, Body_Id, " Analyze subprogram");
-- 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 Ekind (Prev_Id) = E_Generic_Procedure
or else Ekind (Prev_Id) = E_Generic_Function
then
Spec_Id := Prev_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);
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_Spec (Body_Spec);
if Nkind (N) = N_Subprogram_Body_Stub
or else No (Corresponding_Spec (N))
then
Spec_Id := Find_Corresponding_Spec (N);
-- 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 the spec are compilation units.
if No (Spec_Id) then
Freeze_Before (N, Body_Id);
elsif Nkind (Parent (N)) = N_Compilation_Unit then
Freeze_Before (N, Spec_Id);
end if;
else
Spec_Id := Corresponding_Spec (N);
end if;
end if;
if No (Spec_Id)
and then Comes_From_Source (N)
and then Is_Protected_Type (Current_Scope)
then
-- 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.
declare
Decl : Node_Id;
Plist : List_Id;
Formal : Entity_Id;
New_Spec : Node_Id;
begin
Formal := First_Formal (Body_Id);
-- The protected operation always has at least one formal,
-- namely the object itself, but it is only placed in the
-- parameter list if expansion is enabled.
if Present (Formal)
or else Expander_Active
then
Plist := New_List;
else
Plist := No_List;
end if;
while Present (Formal) loop
Append
(Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Sloc (Formal),
Chars => Chars (Formal)),
In_Present => In_Present (Parent (Formal)),
Out_Present => Out_Present (Parent (Formal)),
Parameter_Type =>
New_Reference_To (Etype (Formal), Loc),
Expression =>
New_Copy_Tree (Expression (Parent (Formal)))),
Plist);
Next_Formal (Formal);
end loop;
if Nkind (Body_Spec) = N_Procedure_Specification then
New_Spec :=
Make_Procedure_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Sloc (Body_Id),
Chars => Chars (Body_Id)),
Parameter_Specifications => Plist);
else
New_Spec :=
Make_Function_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Sloc (Body_Id),
Chars => Chars (Body_Id)),
Parameter_Specifications => Plist,
Subtype_Mark => New_Occurrence_Of (Etype (Body_Id), Loc));
end if;
Decl :=
Make_Subprogram_Declaration (Loc,
Specification => New_Spec);
Insert_Before (N, Decl);
Analyze (Decl);
Spec_Id := Defining_Unit_Name (New_Spec);
Set_Has_Completion (Spec_Id);
Set_Convention (Spec_Id, Convention_Protected);
end;
elsif Present (Spec_Id) then
Spec_Decl := Unit_Declaration_Node (Spec_Id);
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');
Style.Check_Identifier (Body_Id, Spec_Id);
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 (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);
if Is_Protected_Type (Scope (Spec_Id)) then
Set_Privals_Chain (Spec_Id, New_Elmt_List);
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 Nkind (Original_Node (Spec_Decl)) =
N_Subprogram_Renaming_Declaration
and then not Comes_From_Source (N)
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;
-- Generate references from body formals to spec formals
-- and also set the Spec_Entity fields for all formals
if Spec_Id /= Body_Id then
declare
Fs : Entity_Id;
Fb : Entity_Id;
begin
Fs := First_Formal (Spec_Id);
Fb := First_Formal (Body_Id);
while Present (Fs) loop
Generate_Reference (Fs, Fb, 'b');
Style.Check_Identifier (Fb, Fs);
Set_Spec_Entity (Fb, Fs);
Next_Formal (Fs);
Next_Formal (Fb);
end loop;
end;
end if;
if Nkind (N) /= N_Subprogram_Body_Stub then
Set_Corresponding_Spec (N, Spec_Id);
Install_Formals (Spec_Id);
Last_Formal := Last_Entity (Spec_Id);
New_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_Ekind (Body_Id, E_Subprogram_Body);
Set_Scope (Body_Id, Scope (Spec_Id));
-- Case of subprogram body with no previous spec
else
if Style_Check
and then Comes_From_Source (Body_Id)
and then not Suppress_Style_Checks (Body_Id)
and then not In_Instance
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);
Install_Formals (Body_Id);
New_Scope (Body_Id);
end if;
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)
then
declare
Conformant : Boolean := False;
Old_Id : Entity_Id :=
Defining_Entity
(Specification (Corresponding_Stub (Parent (N))));
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
return;
elsif Present (Spec_Id)
and then Expander_Active
and then Has_Pragma_Inline (Spec_Id)
and then (Front_End_Inlining
or else
(No_Run_Time and then Is_Always_Inlined (Spec_Id)))
then
if Build_Body_To_Inline (N, Spec_Id, Copy_Separate_Tree (N)) then
null;
end if;
end if;
-- Here we have a real body, not a stub. First step is to null out
-- the subprogram body if we have the special case of no run time
-- mode with a predefined unit, and the subprogram is not marked
-- as Inline_Always. The reason is that we should never call such
-- a routine in no run time mode, and it may in general have some
-- statements that we cannot handle in no run time mode.
-- ASIS note: we do a replace here, because we are really NOT going
-- to analyze the original body and declarations at all, so it is
-- useless to keep them around, we really are obliterating the body,
-- basically creating a specialized no run time version on the fly
-- in which the bodies *are* null.
if No_Run_Time
and then Present (Spec_Id)
and then Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Loc)))
and then not Is_Always_Inlined (Spec_Id)
then
Replace (N,
Make_Subprogram_Body (Loc,
Specification => Specification (N),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Null_Statement (Loc)),
End_Label =>
End_Label (Handled_Statement_Sequence (N)))));
Set_Corresponding_Spec (N, Spec_Id);
Body_Deleted := True;
end if;
-- Now we can go on to analyze the body
HSS := Handled_Statement_Sequence (N);
Set_Actual_Subtypes (N, Current_Scope);
Analyze_Declarations (Declarations (N));
Check_Completion;
Analyze (HSS);
Process_End_Label (HSS, 't');
End_Scope;
Check_Subprogram_Order (N);
-- 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
-- If a parent unit is categorized, the context of a subunit
-- must conform to the categorization. Conversely, if a child
-- unit is categorized, the parents themselves must conform.
if Nkind (Parent (N)) = N_Subunit then
Validate_Categorization_Dependency (N, Spec_Id);
elsif Is_Child_Unit (Spec_Id) then
Validate_Categorization_Dependency
(Unit_Declaration_Node (Spec_Id), Spec_Id);
end if;
if Present (Last_Formal) then
Set_Next_Entity
(Last_Entity (Body_Id), Next_Entity (Last_Formal));
Set_Next_Entity (Last_Formal, Empty);
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_Last_Entity (Spec_Id, Last_Formal);
else
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;
-- If function, check return statements
if Nkind (Body_Spec) = N_Function_Specification then
declare
Id : Entity_Id;
begin
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 not Is_Machine_Code_Subprogram (Id)
and then not Body_Deleted
then
Error_Msg_N ("missing RETURN statement in function body", N);
end if;
end;
-- 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);
end if;
-- Don't worry about checking for variables that are never modified
-- if the first statement of the body is a raise statement, since
-- we assume this is some kind of stub. We ignore a label generated
-- by the exception stuff for the purpose of this test.
declare
Stm : Node_Id := First (Statements (HSS));
begin
if Nkind (Stm) = N_Label then
Next (Stm);
end if;
if Nkind (Original_Node (Stm)) = N_Raise_Statement then
return;
end if;
end;
-- Check for variables that are never modified
declare
E1, E2 : Entity_Id;
begin
-- If there is a separate spec, then transfer Not_Source_Assigned
-- 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);
loop
-- If no matching body entity, then we already had
-- a detected error of some kind, so just forget
-- about worrying about these warnings.
if No (E2) then
return;
end if;
exit when Chars (E1) = Chars (E2);
Next_Entity (E2);
end loop;
Set_Not_Source_Assigned (E2, Not_Source_Assigned (E1));
end if;
Next_Entity (E1);
end loop;
end if;
-- Check references in body unless it was deleted. Note that the
-- check of Body_Deleted here is not just for efficiency, it is
-- necessary to avoid junk warnings on formal parameters.
if not Body_Deleted then
Check_References (Body_Id);
end if;
end;
end Analyze_Subprogram_Body;
------------------------------------
-- Analyze_Subprogram_Declaration --
------------------------------------
procedure Analyze_Subprogram_Declaration (N : Node_Id) is
Designator : constant Entity_Id := Analyze_Spec (Specification (N));
Scop : constant Entity_Id := Current_Scope;
-- Start of processing for Analyze_Subprogram_Declaration
begin
Generate_Definition (Designator);
-- Check for RCI unit subprogram declarations against in-lined
-- subprograms and subprograms having access parameter or limited
-- parameter without Read and Write (RM E.2.3(12-13)).
Validate_RCI_Subprogram_Declaration (N);
Trace_Scope
(N,
Defining_Entity (N),
" Analyze subprogram spec. ");
if Debug_Flag_C then
Write_Str ("==== Compiling subprogram spec ");
Write_Name (Chars (Designator));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
end if;
New_Overloaded_Entity (Designator);
Check_Delayed_Subprogram (Designator);
Set_Suppress_Elaboration_Checks
(Designator, Elaboration_Checks_Suppressed (Designator));
if Scop /= Standard_Standard
and then not Is_Child_Unit (Designator)
then
Set_Is_Pure (Designator,
Is_Pure (Scop) and then Is_Library_Level_Entity (Designator));
Set_Is_Remote_Call_Interface (
Designator, Is_Remote_Call_Interface (Scop));
Set_Is_Remote_Types (Designator, Is_Remote_Types (Scop));
else
-- For a compilation unit, check for library-unit pragmas.
New_Scope (Designator);
Set_Categorization_From_Pragmas (N);
Validate_Categorization_Dependency (N, Designator);
Pop_Scope;
end if;
-- For a compilation unit, set body required. This flag will only be
-- reset if a valid Import or Interface pragma is processed later on.
if Nkind (Parent (N)) = N_Compilation_Unit then
Set_Body_Required (Parent (N), True);
end if;
Check_Eliminated (Designator);
end Analyze_Subprogram_Declaration;
--------------------------
-- Build_Body_To_Inline --
--------------------------
function Build_Body_To_Inline
(N : Node_Id;
Subp : Entity_Id;
Orig_Body : Node_Id) return Boolean
is
Decl : constant Node_Id := Unit_Declaration_Node (Subp);
Original_Body : Node_Id;
Body_To_Analyze : Node_Id;
Max_Size : constant := 10;
Stat_Count : Integer := 0;
function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
-- Check for declarations that make inlining not worthwhile.
function Has_Excluded_Statement (Stats : List_Id) return Boolean;
-- Check for statements that make inlining not worthwhile: any
-- tasking statement, nested at any level. Keep track of total
-- number of elementary statements, as a measure of acceptable size.
function Has_Pending_Instantiation return Boolean;
-- If some enclosing body contains instantiations that appear before
-- the corresponding generic body, the enclosing body has a freeze node
-- so that it can be elaborated after the generic itself. This might
-- conflict with subsequent inlinings, so that it is unsafe to try to
-- inline in such a case.
-------------------
-- Cannot_Inline --
-------------------
procedure Cannot_Inline (Msg : String; N : Node_Id);
-- If subprogram has pragma Inline_Always, it is an error if
-- it cannot be inlined. Otherwise, emit a warning.
procedure Cannot_Inline (Msg : String; N : Node_Id) is
begin
if Is_Always_Inlined (Subp) then
Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp);
elsif Ineffective_Inline_Warnings then
Error_Msg_NE (Msg, N, Subp);
end if;
end Cannot_Inline;
------------------------------
-- Has_Excluded_Declaration --
------------------------------
function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
D : Node_Id;
begin
D := First (Decls);
while Present (D) loop
if Nkind (D) = N_Function_Instantiation
or else Nkind (D) = N_Protected_Type_Declaration
or else Nkind (D) = N_Package_Declaration
or else Nkind (D) = N_Package_Instantiation
or else Nkind (D) = N_Subprogram_Body
or else Nkind (D) = N_Procedure_Instantiation
or else Nkind (D) = N_Task_Type_Declaration
then
Cannot_Inline
("\declaration prevents front-end inlining of&?", D);
return True;
end if;
Next (D);
end loop;
return False;
end Has_Excluded_Declaration;
----------------------------
-- Has_Excluded_Statement --
----------------------------
function Has_Excluded_Statement (Stats : List_Id) return Boolean is
S : Node_Id;
E : Node_Id;
begin
S := First (Stats);
while Present (S) loop
Stat_Count := Stat_Count + 1;
if Nkind (S) = N_Abort_Statement
or else Nkind (S) = N_Asynchronous_Select
or else Nkind (S) = N_Conditional_Entry_Call
or else Nkind (S) = N_Delay_Relative_Statement
or else Nkind (S) = N_Delay_Until_Statement
or else Nkind (S) = N_Selective_Accept
or else Nkind (S) = N_Timed_Entry_Call
then
Cannot_Inline
("\statement prevents front-end inlining of&?", S);
return True;
elsif Nkind (S) = N_Block_Statement then
if Present (Declarations (S))
and then Has_Excluded_Declaration (Declarations (S))
then
return True;
elsif Present (Handled_Statement_Sequence (S))
and then
(Present
(Exception_Handlers (Handled_Statement_Sequence (S)))
or else
Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (S))))
then
return True;
end if;
elsif Nkind (S) = N_Case_Statement then
E := First (Alternatives (S));
while Present (E) loop
if Has_Excluded_Statement (Statements (E)) then
return True;
end if;
Next (E);
end loop;
elsif Nkind (S) = N_If_Statement then
if Has_Excluded_Statement (Then_Statements (S)) then
return True;
end if;
if Present (Elsif_Parts (S)) then
E := First (Elsif_Parts (S));
while Present (E) loop
if Has_Excluded_Statement (Then_Statements (E)) then
return True;
end if;
Next (E);
end loop;
end if;
if Present (Else_Statements (S))
and then Has_Excluded_Statement (Else_Statements (S))
then
return True;
end if;
elsif Nkind (S) = N_Loop_Statement
and then Has_Excluded_Statement (Statements (S))
then
return True;
end if;
Next (S);
end loop;
return False;
end Has_Excluded_Statement;
-------------------------------
-- Has_Pending_Instantiation --
-------------------------------
function Has_Pending_Instantiation return Boolean is
S : Entity_Id := Current_Scope;
begin
while Present (S) loop
if Is_Compilation_Unit (S)
or else Is_Child_Unit (S)
then
return False;
elsif Ekind (S) = E_Package
and then Has_Forward_Instantiation (S)
then
return True;
end if;
S := Scope (S);
end loop;
return False;
end Has_Pending_Instantiation;
-- Start of processing for Build_Body_To_Inline
begin
if Nkind (Decl) = N_Subprogram_Declaration
and then Present (Body_To_Inline (Decl))
then
return True; -- Done already.
-- Functions that return unconstrained composite types will require
-- secondary stack handling, and cannot currently be inlined.
elsif Ekind (Subp) = E_Function
and then not Is_Scalar_Type (Etype (Subp))
and then not Is_Access_Type (Etype (Subp))
and then not Is_Constrained (Etype (Subp))
then
Cannot_Inline
("unconstrained return type prevents front-end inlining of&?", N);
return False;
end if;
-- We need to capture references to the formals in order to substitute
-- the actuals at the point of inlining, i.e. instantiation. To treat
-- the formals as globals to the body to inline, we nest it within
-- a dummy parameterless subprogram, declared within the real one.
Original_Body := Orig_Body;
-- Within an instance, the current tree is already the result of
-- a generic copy, and not what we need for subsequent inlining.
-- We create the required body by doing an instantiating copy, to
-- obtain the proper partially analyzed tree.
if In_Instance then
if No (Generic_Parent (Specification (N))) then
return False;
elsif Is_Child_Unit (Scope (Current_Scope)) then
return False;
elsif Scope (Current_Scope) = Cunit_Entity (Main_Unit) then
-- compiling an instantiation. There is no point in generating
-- bodies to inline, because they will not be used.
return False;
else
Body_To_Analyze :=
Copy_Generic_Node
(Generic_Parent (Specification (N)), Empty,
Instantiating => True);
end if;
else
Body_To_Analyze :=
Copy_Generic_Node (Original_Body, Empty,
Instantiating => False);
end if;
Set_Parameter_Specifications (Specification (Original_Body), No_List);
Set_Defining_Unit_Name (Specification (Original_Body),
Make_Defining_Identifier (Sloc (N), New_Internal_Name ('S')));
Set_Corresponding_Spec (Original_Body, Empty);
if Ekind (Subp) = E_Function then
Set_Subtype_Mark (Specification (Original_Body),
New_Occurrence_Of (Etype (Subp), Sloc (N)));
end if;
if Present (Declarations (Orig_Body))
and then Has_Excluded_Declaration (Declarations (Orig_Body))
then
return False;
end if;
if Present (Handled_Statement_Sequence (N)) then
if
(Present (Exception_Handlers (Handled_Statement_Sequence (N))))
then
Cannot_Inline ("handler prevents front-end inlining of&?",
First (Exception_Handlers (Handled_Statement_Sequence (N))));
return False;
elsif
Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (N)))
then
return False;
end if;
end if;
-- We do not inline a subprogram that is too large, unless it is
-- marked Inline_Always. This pragma does not suppress the other
-- checks on inlining (forbidden declarations, handlers, etc).
if Stat_Count > Max_Size
and then not Is_Always_Inlined (Subp)
then
Cannot_Inline ("body is too large for front-end inlining of&?", N);
return False;
end if;
if Has_Pending_Instantiation then
Cannot_Inline
("cannot inline& because of forward instance within enclosing body",
N);
return False;
end if;
Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
-- Set return type of function, which is also global and does not need
-- to be resolved.
if Ekind (Subp) = E_Function then
Set_Subtype_Mark (Specification (Body_To_Analyze),
New_Occurrence_Of (Etype (Subp), Sloc (N)));
end if;
if No (Declarations (N)) then
Set_Declarations (N, New_List (Body_To_Analyze));
else
Append (Body_To_Analyze, Declarations (N));
end if;
Expander_Mode_Save_And_Set (False);
Analyze (Body_To_Analyze);
New_Scope (Defining_Entity (Body_To_Analyze));
Save_Global_References (Original_Body);
End_Scope;
Remove (Body_To_Analyze);
Expander_Mode_Restore;
Set_Body_To_Inline (Decl, Original_Body);
Set_Is_Inlined (Subp);
return True;
end Build_Body_To_Inline;
-----------------------
-- Check_Conformance --
-----------------------
procedure Check_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Ctype : Conformance_Type;
Errmsg : Boolean;
Conforms : out Boolean;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False)
is
Old_Type : constant Entity_Id := Etype (Old_Id);
New_Type : constant Entity_Id := Etype (New_Id);
Old_Formal : Entity_Id;
New_Formal : Entity_Id;
procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
-- Post error message for conformance error on given node.
-- Two messages are output. The first points to the previous
-- declaration with a general "no conformance" message.
-- The second is the detailed reason, supplied as Msg. The
-- parameter N provide information for a possible & insertion
-- in the message, and also provides the location for posting
-- the message in the absence of a specified Err_Loc location.
-----------------------
-- Conformance_Error --
-----------------------
procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
Enode : Node_Id;
begin
Conforms := False;
if Errmsg then
if No (Err_Loc) then
Enode := N;
else
Enode := Err_Loc;
end if;
Error_Msg_Sloc := Sloc (Old_Id);
case Ctype is
when Type_Conformant =>
Error_Msg_N
("not type conformant with declaration#!", Enode);
when Mode_Conformant =>
Error_Msg_N
("not mode conformant with declaration#!", Enode);
when Subtype_Conformant =>
Error_Msg_N
("not subtype conformant with declaration#!", Enode);
when Fully_Conformant =>
Error_Msg_N
("not fully conformant with declaration#!", Enode);
end case;
Error_Msg_NE (Msg, Enode, N);
end if;
end Conformance_Error;
-- Start of processing for Check_Conformance
begin
Conforms := True;
-- We need a special case for operators, since they don't
-- appear explicitly.
if Ctype = Type_Conformant then
if Ekind (New_Id) = E_Operator
and then Operator_Matches_Spec (New_Id, Old_Id)
then
return;
end if;
end if;
-- If both are functions/operators, check return types conform
if Old_Type /= Standard_Void_Type
and then New_Type /= Standard_Void_Type
then
if not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
Conformance_Error ("return type does not match!", New_Id);
return;
end if;
-- If either is a function/operator and the other isn't, error
elsif Old_Type /= Standard_Void_Type
or else New_Type /= Standard_Void_Type
then
Conformance_Error ("functions can only match functions!", New_Id);
return;
end if;
-- In subtype conformant case, conventions must match (RM 6.3.1(16))
-- If this is a renaming as body, refine error message to indicate that
-- the conflict is with the original declaration. If the entity is not
-- frozen, the conventions don't have to match, the one of the renamed
-- entity is inherited.
if Ctype >= Subtype_Conformant then
if Convention (Old_Id) /= Convention (New_Id) then
if not Is_Frozen (New_Id) then
null;
elsif Present (Err_Loc)
and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
and then Present (Corresponding_Spec (Err_Loc))
then
Error_Msg_Name_1 := Chars (New_Id);
Error_Msg_Name_2 :=
Name_Ada + Convention_Id'Pos (Convention (New_Id));
Conformance_Error ("prior declaration for% has convention %!");
else
Conformance_Error ("calling conventions do not match!");
end if;
return;
elsif Is_Formal_Subprogram (Old_Id)
or else Is_Formal_Subprogram (New_Id)
then
Conformance_Error ("formal subprograms not allowed!");
return;
end if;
end if;
-- Deal with parameters
-- Note: we use the entity information, rather than going directly
-- to the specification in the tree. This is not only simpler, but
-- absolutely necessary for some cases of conformance tests between
-- operators, where the declaration tree simply does not exist!
Old_Formal := First_Formal (Old_Id);
New_Formal := First_Formal (New_Id);
while Present (Old_Formal) and then Present (New_Formal) loop
-- Types must always match. In the visible part of an instance,
-- usual overloading rules for dispatching operations apply, and
-- we check base types (not the actual subtypes).
if In_Instance_Visible_Part
and then Is_Dispatching_Operation (New_Id)
then
if not Conforming_Types
(Base_Type (Etype (Old_Formal)),
Base_Type (Etype (New_Formal)), Ctype, Get_Inst)
then
Conformance_Error ("type of & does not match!", New_Formal);
return;
end if;
elsif not Conforming_Types
(Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst)
then
Conformance_Error ("type of & does not match!", New_Formal);
return;
end if;
-- For mode conformance, mode must match
if Ctype >= Mode_Conformant
and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal)
then
Conformance_Error ("mode of & does not match!", New_Formal);
return;
end if;
-- Full conformance checks
if Ctype = Fully_Conformant then
-- Names must match
if Chars (Old_Formal) /= Chars (New_Formal) then
Conformance_Error ("name & does not match!", New_Formal);
return;
-- And default expressions for in parameters
elsif Parameter_Mode (Old_Formal) = E_In_Parameter then
declare
NewD : constant Boolean :=
Present (Default_Value (New_Formal));
OldD : constant Boolean :=
Present (Default_Value (Old_Formal));
begin
if NewD or OldD then
-- The old default value has been analyzed and expanded,
-- because the current full declaration will have frozen
-- everything before. The new default values have not
-- been expanded, so expand now to check conformance.
if NewD then
New_Scope (New_Id);
Analyze_Default_Expression
(Default_Value (New_Formal), Etype (New_Formal));
End_Scope;
end if;
if not (NewD and OldD)
or else not Fully_Conformant_Expressions
(Default_Value (Old_Formal),
Default_Value (New_Formal))
then
Conformance_Error
("default expression for & does not match!",
New_Formal);
return;
end if;
end if;
end;
end if;
end if;
-- A couple of special checks for Ada 83 mode. These checks are
-- skipped if either entity is an operator in package Standard.
-- or if either old or new instance is not from the source program.
if Ada_83
and then Sloc (Old_Id) > Standard_Location
and then Sloc (New_Id) > Standard_Location
and then Comes_From_Source (Old_Id)
and then Comes_From_Source (New_Id)
then
declare
Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
New_Param : constant Node_Id := Declaration_Node (New_Formal);
begin
-- Explicit IN must be present or absent in both cases. This
-- test is required only in the full conformance case.
if In_Present (Old_Param) /= In_Present (New_Param)
and then Ctype = Fully_Conformant
then
Conformance_Error
("(Ada 83) IN must appear in both declarations",
New_Formal);
return;
end if;
-- Grouping (use of comma in param lists) must be the same
-- This is where we catch a misconformance like:
-- A,B : Integer
-- A : Integer; B : Integer
-- which are represented identically in the tree except
-- for the setting of the flags More_Ids and Prev_Ids.
if More_Ids (Old_Param) /= More_Ids (New_Param)
or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
then
Conformance_Error
("grouping of & does not match!", New_Formal);
return;
end if;
end;
end if;
Next_Formal (Old_Formal);
Next_Formal (New_Formal);
end loop;
if Present (Old_Formal) then
Conformance_Error ("too few parameters!");
return;
elsif Present (New_Formal) then
Conformance_Error ("too many parameters!", New_Formal);
return;
end if;
end Check_Conformance;
------------------------------
-- Check_Delayed_Subprogram --
------------------------------
procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
F : Entity_Id;
procedure Possible_Freeze (T : Entity_Id);
-- T is the type of either a formal parameter or of the return type.
-- If T is not yet frozen and needs a delayed freeze, then the
-- subprogram itself must be delayed.
procedure Possible_Freeze (T : Entity_Id) is
begin
if Has_Delayed_Freeze (T)
and then not Is_Frozen (T)
then
Set_Has_Delayed_Freeze (Designator);
elsif Is_Access_Type (T)
and then Has_Delayed_Freeze (Designated_Type (T))
and then not Is_Frozen (Designated_Type (T))
then
Set_Has_Delayed_Freeze (Designator);
end if;
end Possible_Freeze;
-- Start of processing for Check_Delayed_Subprogram
begin
-- Never need to freeze abstract subprogram
if Is_Abstract (Designator) then
null;
else
-- Need delayed freeze if return type itself needs a delayed
-- freeze and is not yet frozen.
Possible_Freeze (Etype (Designator));
Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
-- Need delayed freeze if any of the formal types themselves need
-- a delayed freeze and are not yet frozen.
F := First_Formal (Designator);
while Present (F) loop
Possible_Freeze (Etype (F));
Possible_Freeze (Base_Type (Etype (F))); -- needed ???
Next_Formal (F);
end loop;
end if;
-- Mark functions that return by reference. Note that it cannot be
-- done for delayed_freeze subprograms because the underlying
-- returned type may not be known yet (for private types)
if not Has_Delayed_Freeze (Designator)
and then Expander_Active
then
declare
Typ : constant Entity_Id := Etype (Designator);
Utyp : constant Entity_Id := Underlying_Type (Typ);
begin
if Is_Return_By_Reference_Type (Typ) then
Set_Returns_By_Ref (Designator);
elsif Present (Utyp) and then Controlled_Type (Utyp) then
Set_Returns_By_Ref (Designator);
end if;
end;
end if;
end Check_Delayed_Subprogram;
------------------------------------
-- Check_Discriminant_Conformance --
------------------------------------
procedure Check_Discriminant_Conformance
(N : Node_Id;
Prev : Entity_Id;
Prev_Loc : Node_Id)
is
Old_Discr : Entity_Id := First_Discriminant (Prev);
New_Discr : Node_Id := First (Discriminant_Specifications (N));
New_Discr_Id : Entity_Id;
New_Discr_Type : Entity_Id;
procedure Conformance_Error (Msg : String; N : Node_Id);
-- Post error message for conformance error on given node.
-- Two messages are output. The first points to the previous
-- declaration with a general "no conformance" message.
-- The second is the detailed reason, supplied as Msg. The
-- parameter N provide information for a possible & insertion
-- in the message.
-----------------------
-- Conformance_Error --
-----------------------
procedure Conformance_Error (Msg : String; N : Node_Id) is
begin
Error_Msg_Sloc := Sloc (Prev_Loc);
Error_Msg_N ("not fully conformant with declaration#!", N);
Error_Msg_NE (Msg, N, N);
end Conformance_Error;
-- Start of processing for Check_Discriminant_Conformance
begin
while Present (Old_Discr) and then Present (New_Discr) loop
New_Discr_Id := Defining_Identifier (New_Discr);
-- The subtype mark of the discriminant on the full type
-- has not been analyzed so we do it here. For an access
-- discriminant a new type is created.
if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
New_Discr_Type :=
Access_Definition (N, Discriminant_Type (New_Discr));
else
Analyze (Discriminant_Type (New_Discr));
New_Discr_Type := Etype (Discriminant_Type (New_Discr));
end if;
if not Conforming_Types
(Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
then
Conformance_Error ("type of & does not match!", New_Discr_Id);
return;
end if;
-- Names must match
if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
Conformance_Error ("name & does not match!", New_Discr_Id);
return;
end if;
-- Default expressions must match
declare
NewD : constant Boolean :=
Present (Expression (New_Discr));
OldD : constant Boolean :=
Present (Expression (Parent (Old_Discr)));
begin
if NewD or OldD then
-- The old default value has been analyzed and expanded,
-- because the current full declaration will have frozen
-- everything before. The new default values have not
-- been expanded, so expand now to check conformance.
if NewD then
Analyze_Default_Expression
(Expression (New_Discr), New_Discr_Type);
end if;
if not (NewD and OldD)
or else not Fully_Conformant_Expressions
(Expression (Parent (Old_Discr)),
Expression (New_Discr))
then
Conformance_Error
("default expression for & does not match!",
New_Discr_Id);
return;
end if;
end if;
end;
-- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
if Ada_83 then
declare
Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
begin
-- Grouping (use of comma in param lists) must be the same
-- This is where we catch a misconformance like:
-- A,B : Integer
-- A : Integer; B : Integer
-- which are represented identically in the tree except
-- for the setting of the flags More_Ids and Prev_Ids.
if More_Ids (Old_Disc) /= More_Ids (New_Discr)
or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
then
Conformance_Error
("grouping of & does not match!", New_Discr_Id);
return;
end if;
end;
end if;
Next_Discriminant (Old_Discr);
Next (New_Discr);
end loop;
if Present (Old_Discr) then
Conformance_Error ("too few discriminants!", Defining_Identifier (N));
return;
elsif Present (New_Discr) then
Conformance_Error
("too many discriminants!", Defining_Identifier (New_Discr));
return;
end if;
end Check_Discriminant_Conformance;
----------------------------
-- Check_Fully_Conformant --
----------------------------
procedure Check_Fully_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
begin
Check_Conformance
(New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
end Check_Fully_Conformant;
---------------------------
-- Check_Mode_Conformant --
---------------------------
procedure Check_Mode_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False)
is
Result : Boolean;
begin
Check_Conformance
(New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
end Check_Mode_Conformant;
-------------------
-- Check_Returns --
-------------------
procedure Check_Returns
(HSS : Node_Id;
Mode : Character;
Err : out Boolean)
is
Handler : Node_Id;
procedure Check_Statement_Sequence (L : List_Id);
-- Internal recursive procedure to check a list of statements for proper
-- termination by a return statement (or a transfer of control or a
-- compound statement that is itself internally properly terminated).
------------------------------
-- Check_Statement_Sequence --
------------------------------
procedure Check_Statement_Sequence (L : List_Id) is
Last_Stm : Node_Id;
Kind : Node_Kind;
Raise_Exception_Call : Boolean;
-- Set True if statement sequence terminated by Raise_Exception call
-- or a Reraise_Occurrence call.
begin
Raise_Exception_Call := False;
-- Get last real statement
Last_Stm := Last (L);
-- Don't count pragmas
while Nkind (Last_Stm) = N_Pragma
-- Don't count call to SS_Release (can happen after Raise_Exception)
or else
(Nkind (Last_Stm) = N_Procedure_Call_Statement
and then
Nkind (Name (Last_Stm)) = N_Identifier
and then
Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
-- Don't count exception junk
or else
((Nkind (Last_Stm) = N_Goto_Statement
or else Nkind (Last_Stm) = N_Label
or else Nkind (Last_Stm) = N_Object_Declaration)
and then Exception_Junk (Last_Stm))
loop
Prev (Last_Stm);
end loop;
-- Here we have the "real" last statement
Kind := Nkind (Last_Stm);
-- Transfer of control, OK. Note that in the No_Return procedure
-- case, we already diagnosed any explicit return statements, so
-- we can treat them as OK in this context.
if Is_Transfer (Last_Stm) then
return;
-- Check cases of explicit non-indirect procedure calls
elsif Kind = N_Procedure_Call_Statement
and then Is_Entity_Name (Name (Last_Stm))
then
-- Check call to Raise_Exception procedure which is treated
-- specially, as is a call to Reraise_Occurrence.
-- We suppress the warning in these cases since it is likely that
-- the programmer really does not expect to deal with the case
-- of Null_Occurrence, and thus would find a warning about a
-- missing return curious, and raising Program_Error does not
-- seem such a bad behavior if this does occur.
if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
or else
Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
then
Raise_Exception_Call := True;
-- For Raise_Exception call, test first argument, if it is
-- an attribute reference for a 'Identity call, then we know
-- that the call cannot possibly return.
declare
Arg : constant Node_Id :=
Original_Node (First_Actual (Last_Stm));
begin
if Nkind (Arg) = N_Attribute_Reference
and then Attribute_Name (Arg) = Name_Identity
then
return;
end if;
end;
end if;
-- If statement, need to look inside if there is an else and check
-- each constituent statement sequence for proper termination.
elsif Kind = N_If_Statement
and then Present (Else_Statements (Last_Stm))
then
Check_Statement_Sequence (Then_Statements (Last_Stm));
Check_Statement_Sequence (Else_Statements (Last_Stm));
if Present (Elsif_Parts (Last_Stm)) then
declare
Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
begin
while Present (Elsif_Part) loop
Check_Statement_Sequence (Then_Statements (Elsif_Part));
Next (Elsif_Part);
end loop;
end;
end if;
return;
-- Case statement, check each case for proper termination
elsif Kind = N_Case_Statement then
declare
Case_Alt : Node_Id;
begin
Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
while Present (Case_Alt) loop
Check_Statement_Sequence (Statements (Case_Alt));
Next_Non_Pragma (Case_Alt);
end loop;
end;
return;
-- Block statement, check its handled sequence of statements
elsif Kind = N_Block_Statement then
declare
Err1 : Boolean;
begin
Check_Returns
(Handled_Statement_Sequence (Last_Stm), Mode, Err1);
if Err1 then
Err := True;
end if;
return;
end;
-- Loop statement. If there is an iteration scheme, we can definitely
-- fall out of the loop. Similarly if there is an exit statement, we
-- can fall out. In either case we need a following return.
elsif Kind = N_Loop_Statement then
if Present (Iteration_Scheme (Last_Stm))
or else Has_Exit (Entity (Identifier (Last_Stm)))
then
null;
-- A loop with no exit statement or iteration scheme if either
-- an inifite loop, or it has some other exit (raise/return).
-- In either case, no warning is required.
else
return;
end if;
-- Timed entry call, check entry call and delay alternatives
-- Note: in expanded code, the timed entry call has been converted
-- to a set of expanded statements on which the check will work
-- correctly in any case.
elsif Kind = N_Timed_Entry_Call then
declare
ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
DCA : constant Node_Id := Delay_Alternative (Last_Stm);
begin
-- If statement sequence of entry call alternative is missing,
-- then we can definitely fall through, and we post the error
-- message on the entry call alternative itself.
if No (Statements (ECA)) then
Last_Stm := ECA;
-- If statement sequence of delay alternative is missing, then
-- we can definitely fall through, and we post the error
-- message on the delay alternative itself.
-- Note: if both ECA and DCA are missing the return, then we
-- post only one message, should be enough to fix the bugs.
-- If not we will get a message next time on the DCA when the
-- ECA is fixed!
elsif No (Statements (DCA)) then
Last_Stm := DCA;
-- Else check both statement sequences
else
Check_Statement_Sequence (Statements (ECA));
Check_Statement_Sequence (Statements (DCA));
return;
end if;
end;
-- Conditional entry call, check entry call and else part
-- Note: in expanded code, the conditional entry call has been
-- converted to a set of expanded statements on which the check
-- will work correctly in any case.
elsif Kind = N_Conditional_Entry_Call then
declare
ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
begin
-- If statement sequence of entry call alternative is missing,
-- then we can definitely fall through, and we post the error
-- message on the entry call alternative itself.
if No (Statements (ECA)) then
Last_Stm := ECA;
-- Else check statement sequence and else part
else
Check_Statement_Sequence (Statements (ECA));
Check_Statement_Sequence (Else_Statements (Last_Stm));
return;
end if;
end;
end if;
-- If we fall through, issue appropriate message
if Mode = 'F' then
if not Raise_Exception_Call then
Error_Msg_N
("?RETURN statement missing following this statement!",
Last_Stm);
Error_Msg_N
("\?Program_Error may be raised at run time",
Last_Stm);
end if;
-- Note: we set Err even though we have not issued a warning
-- because we still have a case of a missing return. This is
-- an extremely marginal case, probably will never be noticed
-- but we might as well get it right.
Err := True;
else
Error_Msg_N
("implied return after this statement not allowed (No_Return)",
Last_Stm);
end if;
end Check_Statement_Sequence;
-- Start of processing for Check_Returns
begin
Err := False;
Check_Statement_Sequence (Statements (HSS));
if Present (Exception_Handlers (HSS)) then
Handler := First_Non_Pragma (Exception_Handlers (HSS));
while Present (Handler) loop
Check_Statement_Sequence (Statements (Handler));
Next_Non_Pragma (Handler);
end loop;
end if;
end Check_Returns;
----------------------------
-- Check_Subprogram_Order --
----------------------------
procedure Check_Subprogram_Order (N : Node_Id) is
function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
-- This is used to check if S1 > S2 in the sense required by this
-- test, for example nameab < namec, but name2 < name10.
function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
L1, L2 : Positive;
N1, N2 : Natural;
begin
-- Remove trailing numeric parts
L1 := S1'Last;
while S1 (L1) in '0' .. '9' loop
L1 := L1 - 1;
end loop;
L2 := S2'Last;
while S2 (L2) in '0' .. '9' loop
L2 := L2 - 1;
end loop;
-- If non-numeric parts non-equal, that's decisive
if S1 (S1'First .. L1) < S2 (S2'First .. L2) then
return False;
elsif S1 (S1'First .. L1) > S2 (S2'First .. L2) then
return True;
-- If non-numeric parts equal, compare suffixed numeric parts. Note
-- that a missing suffix is treated as numeric zero in this test.
else
N1 := 0;
while L1 < S1'Last loop
L1 := L1 + 1;
N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
end loop;
N2 := 0;
while L2 < S2'Last loop
L2 := L2 + 1;
N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
end loop;
return N1 > N2;
end if;
end Subprogram_Name_Greater;
-- Start of processing for Check_Subprogram_Order
begin
-- Check body in alpha order if this is option
if Style_Check_Subprogram_Order
and then Nkind (N) = N_Subprogram_Body
and then Comes_From_Source (N)
and then In_Extended_Main_Source_Unit (N)
then
declare
LSN : String_Ptr
renames Scope_Stack.Table
(Scope_Stack.Last).Last_Subprogram_Name;
Body_Id : constant Entity_Id :=
Defining_Entity (Specification (N));
begin
Get_Decoded_Name_String (Chars (Body_Id));
if LSN /= null then
if Subprogram_Name_Greater
(LSN.all, Name_Buffer (1 .. Name_Len))
then
Style.Subprogram_Not_In_Alpha_Order (Body_Id);
end if;
Free (LSN);
end if;
LSN := new String'(Name_Buffer (1 .. Name_Len));
end;
end if;
end Check_Subprogram_Order;
------------------------------
-- Check_Subtype_Conformant --
------------------------------
procedure Check_Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
begin
Check_Conformance
(New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
end Check_Subtype_Conformant;
---------------------------
-- Check_Type_Conformant --
---------------------------
procedure Check_Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
begin
Check_Conformance
(New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
end Check_Type_Conformant;
----------------------
-- Conforming_Types --
----------------------
function Conforming_Types
(T1 : Entity_Id;
T2 : Entity_Id;
Ctype : Conformance_Type;
Get_Inst : Boolean := False)
return Boolean
is
Type_1 : Entity_Id := T1;
Type_2 : Entity_Id := T2;
function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
-- If neither T1 nor T2 are generic actual types, then verify
-- that the base types are equal. Otherwise T1 and T2 must be
-- on the same subtype chain. The whole purpose of this procedure
-- is to prevent spurious ambiguities in an instantiation that may
-- arise if two distinct generic types are instantiated with the
-- same actual.
----------------------
-- Base_Types_Match --
----------------------
function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
begin
if T1 = T2 then
return True;
elsif Base_Type (T1) = Base_Type (T2) then
-- The following is too permissive. A more precise test must
-- check that the generic actual is an ancestor subtype of the
-- other ???.
return not Is_Generic_Actual_Type (T1)
or else not Is_Generic_Actual_Type (T2);
else
return False;
end if;
end Base_Types_Match;
begin
-- The context is an instance association for a formal
-- access-to-subprogram type; the formal parameter types
-- require mapping because they may denote other formal
-- parameters of the generic unit.
if Get_Inst then
Type_1 := Get_Instance_Of (T1);
Type_2 := Get_Instance_Of (T2);
end if;
-- First see if base types match
if Base_Types_Match (Type_1, Type_2) then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Type_2);
elsif Is_Incomplete_Or_Private_Type (Type_1)
and then Present (Full_View (Type_1))
and then Base_Types_Match (Full_View (Type_1), Type_2)
then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
elsif Ekind (Type_2) = E_Incomplete_Type
and then Present (Full_View (Type_2))
and then Base_Types_Match (Type_1, Full_View (Type_2))
then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
end if;
-- Test anonymous access type case. For this case, static subtype
-- matching is required for mode conformance (RM 6.3.1(15))
if Ekind (Type_1) = E_Anonymous_Access_Type
and then Ekind (Type_2) = E_Anonymous_Access_Type
then
declare
Desig_1 : Entity_Id;
Desig_2 : Entity_Id;
begin
Desig_1 := Directly_Designated_Type (Type_1);
-- An access parameter can designate an incomplete type.
if Ekind (Desig_1) = E_Incomplete_Type
and then Present (Full_View (Desig_1))
then
Desig_1 := Full_View (Desig_1);
end if;
Desig_2 := Directly_Designated_Type (Type_2);
if Ekind (Desig_2) = E_Incomplete_Type
and then Present (Full_View (Desig_2))
then
Desig_2 := Full_View (Desig_2);
end if;
-- The context is an instance association for a formal
-- access-to-subprogram type; formal access parameter
-- designated types require mapping because they may
-- denote other formal parameters of the generic unit.
if Get_Inst then
Desig_1 := Get_Instance_Of (Desig_1);
Desig_2 := Get_Instance_Of (Desig_2);
end if;
-- It is possible for a Class_Wide_Type to be introduced for
-- an incomplete type, in which case there is a separate class_
-- wide type for the full view. The types conform if their
-- Etypes conform, i.e. one may be the full view of the other.
-- This can only happen in the context of an access parameter,
-- other uses of an incomplete Class_Wide_Type are illegal.
if Ekind (Desig_1) = E_Class_Wide_Type
and then Ekind (Desig_2) = E_Class_Wide_Type
then
return
Conforming_Types (Etype (Desig_1), Etype (Desig_2), Ctype);
else
return Base_Type (Desig_1) = Base_Type (Desig_2)
and then (Ctype = Type_Conformant
or else
Subtypes_Statically_Match (Desig_1, Desig_2));
end if;
end;
-- Otherwise definitely no match
else
return False;
end if;
end Conforming_Types;
--------------------------
-- Create_Extra_Formals --
--------------------------
procedure Create_Extra_Formals (E : Entity_Id) is
Formal : Entity_Id;
Last_Formal : Entity_Id;
Last_Extra : Entity_Id;
Formal_Type : Entity_Id;
P_Formal : Entity_Id := Empty;
function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
-- Add an extra formal, associated with the current Formal. The
-- extra formal is added to the list of extra formals, and also
-- returned as the result. These formals are always of mode IN.
function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
EF : constant Entity_Id :=
Make_Defining_Identifier (Sloc (Formal),
Chars => New_External_Name (Chars (Formal), 'F'));
begin
-- We never generate extra formals if expansion is not active
-- because we don't need them unless we are generating code.
if not Expander_Active then
return Empty;
end if;
-- A little optimization. Never generate an extra formal for
-- the _init operand of an initialization procedure, since it
-- could never be used.
if Chars (Formal) = Name_uInit then
return Empty;
end if;
Set_Ekind (EF, E_In_Parameter);
Set_Actual_Subtype (EF, Typ);
Set_Etype (EF, Typ);
Set_Scope (EF, Scope (Formal));
Set_Mechanism (EF, Default_Mechanism);
Set_Formal_Validity (EF);
Set_Extra_Formal (Last_Extra, EF);
Last_Extra := EF;
return EF;
end Add_Extra_Formal;
-- Start of processing for Create_Extra_Formals
begin
-- If this is a derived subprogram then the subtypes of the
-- parent subprogram's formal parameters will be used to
-- to determine the need for extra formals.
if Is_Overloadable (E) and then Present (Alias (E)) then
P_Formal := First_Formal (Alias (E));
end if;
Last_Extra := Empty;
Formal := First_Formal (E);
while Present (Formal) loop
Last_Extra := Formal;
Next_Formal (Formal);
end loop;
-- If Extra_formals where already created, don't do it again
-- This situation may arise for subprogram types created as part
-- of dispatching calls (see Expand_Dispatch_Call)
if Present (Last_Extra) and then
Present (Extra_Formal (Last_Extra))
then
return;
end if;
Formal := First_Formal (E);
while Present (Formal) loop
-- Create extra formal for supporting the attribute 'Constrained.
-- The case of a private type view without discriminants also
-- requires the extra formal if the underlying type has defaulted
-- discriminants.
if Ekind (Formal) /= E_In_Parameter then
if Present (P_Formal) then
Formal_Type := Etype (P_Formal);
else
Formal_Type := Etype (Formal);
end if;
if not Has_Discriminants (Formal_Type)
and then Ekind (Formal_Type) in Private_Kind
and then Present (Underlying_Type (Formal_Type))
then
Formal_Type := Underlying_Type (Formal_Type);
end if;
if Has_Discriminants (Formal_Type)
and then
((not Is_Constrained (Formal_Type)
and then not Is_Indefinite_Subtype (Formal_Type))
or else Present (Extra_Formal (Formal)))
then
Set_Extra_Constrained
(Formal, Add_Extra_Formal (Standard_Boolean));
end if;
end if;
-- Create extra formal for supporting accessibility checking
-- This is suppressed if we specifically suppress accessibility
-- checks for either the subprogram, or the package in which it
-- resides. However, we do not suppress it simply if the scope
-- has accessibility checks suppressed, since this could cause
-- trouble when clients are compiled with a different suppression
-- setting. The explicit checks are safe from this point of view.
if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
and then not
(Suppress_Accessibility_Checks (E)
or else
Suppress_Accessibility_Checks (Scope (E)))
and then
(not Present (P_Formal)
or else Present (Extra_Accessibility (P_Formal)))
then
-- Temporary kludge: for now we avoid creating the extra
-- formal for access parameters of protected operations
-- because of problem with the case of internal protected
-- calls. ???
if Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Definition
and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body
then
Set_Extra_Accessibility
(Formal, Add_Extra_Formal (Standard_Natural));
end if;
end if;
if Present (P_Formal) then
Next_Formal (P_Formal);
end if;
Last_Formal := Formal;
Next_Formal (Formal);
end loop;
end Create_Extra_Formals;
-----------------------------
-- Enter_Overloaded_Entity --
-----------------------------
procedure Enter_Overloaded_Entity (S : Entity_Id) is
E : Entity_Id := Current_Entity_In_Scope (S);
C_E : Entity_Id := Current_Entity (S);
begin
if Present (E) then
Set_Has_Homonym (E);
Set_Has_Homonym (S);
end if;
Set_Is_Immediately_Visible (S);
Set_Scope (S, Current_Scope);
-- Chain new entity if front of homonym in current scope, so that
-- homonyms are contiguous.
if Present (E)
and then E /= C_E
then
while Homonym (C_E) /= E loop
C_E := Homonym (C_E);
end loop;
Set_Homonym (C_E, S);
else
E := C_E;
Set_Current_Entity (S);
end if;
Set_Homonym (S, E);
Append_Entity (S, Current_Scope);
Set_Public_Status (S);
if Debug_Flag_E then
Write_Str ("New overloaded entity chain: ");
Write_Name (Chars (S));
E := S;
while Present (E) loop
Write_Str (" "); Write_Int (Int (E));
E := Homonym (E);
end loop;
Write_Eol;
end if;
-- Generate warning for hiding
if Warn_On_Hiding
and then Comes_From_Source (S)
and then In_Extended_Main_Source_Unit (S)
then
E := S;
loop
E := Homonym (E);
exit when No (E);
-- Warn unless genuine overloading
if (not Is_Overloadable (E))
or else Subtype_Conformant (E, S)
then
Error_Msg_Sloc := Sloc (E);
Error_Msg_N ("declaration of & hides one#?", S);
end if;
end loop;
end if;
end Enter_Overloaded_Entity;
-----------------------------
-- Find_Corresponding_Spec --
-----------------------------
function Find_Corresponding_Spec (N : Node_Id) return Entity_Id is
Spec : constant Node_Id := Specification (N);
Designator : constant Entity_Id := Defining_Entity (Spec);
E : Entity_Id;
begin
E := Current_Entity (Designator);
while Present (E) loop
-- We are looking for a matching spec. It must have the same scope,
-- and the same name, and either be type conformant, or be the case
-- of a library procedure spec and its body (which belong to one
-- another regardless of whether they are type conformant or not).
if Scope (E) = Current_Scope then
if (Current_Scope = Standard_Standard
or else (Ekind (E) = Ekind (Designator)
and then
Type_Conformant (E, Designator)))
then
-- Within an instantiation, we know that spec and body are
-- subtype conformant, because they were subtype conformant
-- in the generic. We choose the subtype-conformant entity
-- here as well, to resolve spurious ambiguities in the
-- instance that were not present in the generic (i.e. when
-- two different types are given the same actual). If we are
-- looking for a spec to match a body, full conformance is
-- expected.
if In_Instance then
Set_Convention (Designator, Convention (E));
if Nkind (N) = N_Subprogram_Body
and then Present (Homonym (E))
and then not Fully_Conformant (E, Designator)
then
goto Next_Entity;
elsif not Subtype_Conformant (E, Designator) then
goto Next_Entity;
end if;
end if;
if not Has_Completion (E) then
if Nkind (N) /= N_Subprogram_Body_Stub then
Set_Corresponding_Spec (N, E);
end if;
Set_Has_Completion (E);
return E;
elsif Nkind (Parent (N)) = N_Subunit then
-- If this is the proper body of a subunit, the completion
-- flag is set when analyzing the stub.
return E;
-- If body already exists, this is an error unless the
-- previous declaration is the implicit declaration of
-- a derived subprogram, or this is a spurious overloading
-- in an instance.
elsif No (Alias (E))
and then not Is_Intrinsic_Subprogram (E)
and then not In_Instance
then
Error_Msg_Sloc := Sloc (E);
Error_Msg_NE ("duplicate body for & declared#", N, E);
end if;
elsif Is_Child_Unit (E)
and then
Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
and then
Nkind (Parent (Unit_Declaration_Node (Designator)))
= N_Compilation_Unit
then
-- Child units cannot be overloaded, so a conformance mismatch
-- between body and a previous spec is an error.
Error_Msg_N
("body of child unit does not match previous declaration", N);
end if;
end if;
<<Next_Entity>>
E := Homonym (E);
end loop;
-- On exit, we know that no previous declaration of subprogram exists
return Empty;
end Find_Corresponding_Spec;
----------------------
-- Fully_Conformant --
----------------------
function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
return Result;
end Fully_Conformant;
----------------------------------
-- Fully_Conformant_Expressions --
----------------------------------
function Fully_Conformant_Expressions
(Given_E1 : Node_Id;
Given_E2 : Node_Id)
return Boolean
is
E1 : constant Node_Id := Original_Node (Given_E1);
E2 : constant Node_Id := Original_Node (Given_E2);
-- We always test conformance on original nodes, since it is possible
-- for analysis and/or expansion to make things look as though they
-- conform when they do not, e.g. by converting 1+2 into 3.
function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
renames Fully_Conformant_Expressions;
function FCL (L1, L2 : List_Id) return Boolean;
-- Compare elements of two lists for conformance. Elements have to
-- be conformant, and actuals inserted as default parameters do not
-- match explicit actuals with the same value.
function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
-- Compare an operator node with a function call.
---------
-- FCL --
---------
function FCL (L1, L2 : List_Id) return Boolean is
N1, N2 : Node_Id;
begin
if L1 = No_List then
N1 := Empty;
else
N1 := First (L1);
end if;
if L2 = No_List then
N2 := Empty;
else
N2 := First (L2);
end if;
-- Compare two lists, skipping rewrite insertions (we want to
-- compare the original trees, not the expanded versions!)
loop
if Is_Rewrite_Insertion (N1) then
Next (N1);
elsif Is_Rewrite_Insertion (N2) then
Next (N2);
elsif No (N1) then
return No (N2);
elsif No (N2) then
return False;
elsif not FCE (N1, N2) then
return False;
else
Next (N1);
Next (N2);
end if;
end loop;
end FCL;
---------
-- FCO --
---------
function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
Actuals : constant List_Id := Parameter_Associations (Call_Node);
Act : Node_Id;
begin
if No (Actuals)
or else Entity (Op_Node) /= Entity (Name (Call_Node))
then
return False;
else
Act := First (Actuals);
if Nkind (Op_Node) in N_Binary_Op then
if not FCE (Left_Opnd (Op_Node), Act) then
return False;
end if;
Next (Act);
end if;
return Present (Act)
and then FCE (Right_Opnd (Op_Node), Act)
and then No (Next (Act));
end if;
end FCO;
-- Start of processing for Fully_Conformant_Expressions
begin
-- Non-conformant if paren count does not match. Note: if some idiot
-- complains that we don't do this right for more than 3 levels of
-- parentheses, they will be treated with the respect they deserve :-)
if Paren_Count (E1) /= Paren_Count (E2) then
return False;
-- If same entities are referenced, then they are conformant
-- even if they have different forms (RM 8.3.1(19-20)).
elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
if Present (Entity (E1)) then
return Entity (E1) = Entity (E2)
or else (Chars (Entity (E1)) = Chars (Entity (E2))
and then Ekind (Entity (E1)) = E_Discriminant
and then Ekind (Entity (E2)) = E_In_Parameter);
elsif Nkind (E1) = N_Expanded_Name
and then Nkind (E2) = N_Expanded_Name
and then Nkind (Selector_Name (E1)) = N_Character_Literal
and then Nkind (Selector_Name (E2)) = N_Character_Literal
then
return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
else
-- Identifiers in component associations don't always have
-- entities, but their names must conform.
return Nkind (E1) = N_Identifier
and then Nkind (E2) = N_Identifier
and then Chars (E1) = Chars (E2);
end if;
elsif Nkind (E1) = N_Character_Literal
and then Nkind (E2) = N_Expanded_Name
then
return Nkind (Selector_Name (E2)) = N_Character_Literal
and then Chars (E1) = Chars (Selector_Name (E2));
elsif Nkind (E2) = N_Character_Literal
and then Nkind (E1) = N_Expanded_Name
then
return Nkind (Selector_Name (E1)) = N_Character_Literal
and then Chars (E2) = Chars (Selector_Name (E1));
elsif Nkind (E1) in N_Op
and then Nkind (E2) = N_Function_Call
then
return FCO (E1, E2);
elsif Nkind (E2) in N_Op
and then Nkind (E1) = N_Function_Call
then
return FCO (E2, E1);
-- Otherwise we must have the same syntactic entity
elsif Nkind (E1) /= Nkind (E2) then
return False;
-- At this point, we specialize by node type
else
case Nkind (E1) is
when N_Aggregate =>
return
FCL (Expressions (E1), Expressions (E2))
and then FCL (Component_Associations (E1),
Component_Associations (E2));
when N_Allocator =>
if Nkind (Expression (E1)) = N_Qualified_Expression
or else
Nkind (Expression (E2)) = N_Qualified_Expression
then
return FCE (Expression (E1), Expression (E2));
-- Check that the subtype marks and any constraints
-- are conformant
else
declare
Indic1 : constant Node_Id := Expression (E1);
Indic2 : constant Node_Id := Expression (E2);
Elt1 : Node_Id;
Elt2 : Node_Id;
begin
if Nkind (Indic1) /= N_Subtype_Indication then
return
Nkind (Indic2) /= N_Subtype_Indication
and then Entity (Indic1) = Entity (Indic2);
elsif Nkind (Indic2) /= N_Subtype_Indication then
return
Nkind (Indic1) /= N_Subtype_Indication
and then Entity (Indic1) = Entity (Indic2);
else
if Entity (Subtype_Mark (Indic1)) /=
Entity (Subtype_Mark (Indic2))
then
return False;
end if;
Elt1 := First (Constraints (Constraint (Indic1)));
Elt2 := First (Constraints (Constraint (Indic2)));
while Present (Elt1) and then Present (Elt2) loop
if not FCE (Elt1, Elt2) then
return False;
end if;
Next (Elt1);
Next (Elt2);
end loop;
return True;
end if;
end;
end if;
when N_Attribute_Reference =>
return
Attribute_Name (E1) = Attribute_Name (E2)
and then FCL (Expressions (E1), Expressions (E2));
when N_Binary_Op =>
return
Entity (E1) = Entity (E2)
and then FCE (Left_Opnd (E1), Left_Opnd (E2))
and then FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_And_Then | N_Or_Else | N_In | N_Not_In =>
return
FCE (Left_Opnd (E1), Left_Opnd (E2))
and then
FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Character_Literal =>
return
Char_Literal_Value (E1) = Char_Literal_Value (E2);
when N_Component_Association =>
return
FCL (Choices (E1), Choices (E2))
and then FCE (Expression (E1), Expression (E2));
when N_Conditional_Expression =>
return
FCL (Expressions (E1), Expressions (E2));
when N_Explicit_Dereference =>
return
FCE (Prefix (E1), Prefix (E2));
when N_Extension_Aggregate =>
return
FCL (Expressions (E1), Expressions (E2))
and then Null_Record_Present (E1) =
Null_Record_Present (E2)
and then FCL (Component_Associations (E1),
Component_Associations (E2));
when N_Function_Call =>
return
FCE (Name (E1), Name (E2))
and then FCL (Parameter_Associations (E1),
Parameter_Associations (E2));
when N_Indexed_Component =>
return
FCE (Prefix (E1), Prefix (E2))
and then FCL (Expressions (E1), Expressions (E2));
when N_Integer_Literal =>
return (Intval (E1) = Intval (E2));
when N_Null =>
return True;
when N_Operator_Symbol =>
return
Chars (E1) = Chars (E2);
when N_Others_Choice =>
return True;
when N_Parameter_Association =>
return
Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
and then FCE (Explicit_Actual_Parameter (E1),
Explicit_Actual_Parameter (E2));
when N_Qualified_Expression =>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then FCE (Expression (E1), Expression (E2));
when N_Range =>
return
FCE (Low_Bound (E1), Low_Bound (E2))
and then FCE (High_Bound (E1), High_Bound (E2));
when N_Real_Literal =>
return (Realval (E1) = Realval (E2));
when N_Selected_Component =>
return
FCE (Prefix (E1), Prefix (E2))
and then FCE (Selector_Name (E1), Selector_Name (E2));
when N_Slice =>
return
FCE (Prefix (E1), Prefix (E2))
and then FCE (Discrete_Range (E1), Discrete_Range (E2));
when N_String_Literal =>
declare
S1 : constant String_Id := Strval (E1);
S2 : constant String_Id := Strval (E2);
L1 : constant Nat := String_Length (S1);
L2 : constant Nat := String_Length (S2);
begin
if L1 /= L2 then
return False;
else
for J in 1 .. L1 loop
if Get_String_Char (S1, J) /=
Get_String_Char (S2, J)
then
return False;
end if;
end loop;
return True;
end if;
end;
when N_Type_Conversion =>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then FCE (Expression (E1), Expression (E2));
when N_Unary_Op =>
return
Entity (E1) = Entity (E2)
and then FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Unchecked_Type_Conversion =>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then FCE (Expression (E1), Expression (E2));
-- All other node types cannot appear in this context. Strictly
-- we should raise a fatal internal error. Instead we just ignore
-- the nodes. This means that if anyone makes a mistake in the
-- expander and mucks an expression tree irretrievably, the
-- result will be a failure to detect a (probably very obscure)
-- case of non-conformance, which is better than bombing on some
-- case where two expressions do in fact conform.
when others =>
return True;
end case;
end if;
end Fully_Conformant_Expressions;
--------------------
-- Install_Entity --
--------------------
procedure Install_Entity (E : Entity_Id) is
Prev : constant Entity_Id := Current_Entity (E);
begin
Set_Is_Immediately_Visible (E);
Set_Current_Entity (E);
Set_Homonym (E, Prev);
end Install_Entity;
---------------------
-- Install_Formals --
---------------------
procedure Install_Formals (Id : Entity_Id) is
F : Entity_Id;
begin
F := First_Formal (Id);
while Present (F) loop
Install_Entity (F);
Next_Formal (F);
end loop;
end Install_Formals;
---------------------------------
-- Is_Non_Overriding_Operation --
---------------------------------
function Is_Non_Overriding_Operation
(Prev_E : Entity_Id;
New_E : Entity_Id)
return Boolean
is
Formal : Entity_Id;
F_Typ : Entity_Id;
G_Typ : Entity_Id := Empty;
function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
-- If F_Type is a derived type associated with a generic actual
-- subtype, then return its Generic_Parent_Type attribute, else
-- return Empty.
function Types_Correspond
(P_Type : Entity_Id;
N_Type : Entity_Id)
return Boolean;
-- Returns true if and only if the types (or designated types
-- in the case of anonymous access types) are the same or N_Type
-- is derived directly or indirectly from P_Type.
-----------------------------
-- Get_Generic_Parent_Type --
-----------------------------
function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
G_Typ : Entity_Id;
Indic : Node_Id;
begin
if Is_Derived_Type (F_Typ)
and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
then
-- The tree must be traversed to determine the parent
-- subtype in the generic unit, which unfortunately isn't
-- always available via semantic attributes. ???
-- (Note: The use of Original_Node is needed for cases
-- where a full derived type has been rewritten.)
Indic := Subtype_Indication
(Type_Definition (Original_Node (Parent (F_Typ))));
if Nkind (Indic) = N_Subtype_Indication then
G_Typ := Entity (Subtype_Mark (Indic));
else
G_Typ := Entity (Indic);
end if;
if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
and then Present (Generic_Parent_Type (Parent (G_Typ)))
then
return Generic_Parent_Type (Parent (G_Typ));
end if;
end if;
return Empty;
end Get_Generic_Parent_Type;
----------------------
-- Types_Correspond --
----------------------
function Types_Correspond
(P_Type : Entity_Id;
N_Type : Entity_Id)
return Boolean
is
Prev_Type : Entity_Id := Base_Type (P_Type);
New_Type : Entity_Id := Base_Type (N_Type);
begin
if Ekind (Prev_Type) = E_Anonymous_Access_Type then
Prev_Type := Designated_Type (Prev_Type);
end if;
if Ekind (New_Type) = E_Anonymous_Access_Type then
New_Type := Designated_Type (New_Type);
end if;
if Prev_Type = New_Type then
return True;
elsif not Is_Class_Wide_Type (New_Type) then
while Etype (New_Type) /= New_Type loop
New_Type := Etype (New_Type);
if New_Type = Prev_Type then
return True;
end if;
end loop;
end if;
return False;
end Types_Correspond;
-- Start of processing for Is_Non_Overriding_Operation
begin
-- In the case where both operations are implicit derived
-- subprograms then neither overrides the other. This can
-- only occur in certain obscure cases (e.g., derivation
-- from homographs created in a generic instantiation).
if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
return True;
elsif Ekind (Current_Scope) = E_Package
and then Is_Generic_Instance (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Comes_From_Source (New_E)
then
-- We examine the formals and result subtype of the inherited
-- operation, to determine whether their type is derived from
-- (the instance of) a generic type.
Formal := First_Formal (Prev_E);
while Present (Formal) loop
F_Typ := Base_Type (Etype (Formal));
if Ekind (F_Typ) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (F_Typ);
end if;
G_Typ := Get_Generic_Parent_Type (F_Typ);
Next_Formal (Formal);
end loop;
if not Present (G_Typ) and then Ekind (Prev_E) = E_Function then
G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
end if;
if No (G_Typ) then
return False;
end if;
-- If the generic type is a private type, then the original
-- operation was not overriding in the generic, because there was
-- no primitive operation to override.
if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
N_Formal_Private_Type_Definition
then
return True;
-- The generic parent type is the ancestor of a formal derived
-- type declaration. We need to check whether it has a primitive
-- operation that should be overridden by New_E in the generic.
else
declare
P_Formal : Entity_Id;
N_Formal : Entity_Id;
P_Typ : Entity_Id;
N_Typ : Entity_Id;
P_Prim : Entity_Id;
Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
begin
while Present (Prim_Elt) loop
P_Prim := Node (Prim_Elt);
if Chars (P_Prim) = Chars (New_E)
and then Ekind (P_Prim) = Ekind (New_E)
then
P_Formal := First_Formal (P_Prim);
N_Formal := First_Formal (New_E);
while Present (P_Formal) and then Present (N_Formal) loop
P_Typ := Etype (P_Formal);
N_Typ := Etype (N_Formal);
if not Types_Correspond (P_Typ, N_Typ) then
exit;
end if;
Next_Entity (P_Formal);
Next_Entity (N_Formal);
end loop;
-- Found a matching primitive operation belonging to
-- the formal ancestor type, so the new subprogram
-- is overriding.
if not Present (P_Formal)
and then not Present (N_Formal)
and then (Ekind (New_E) /= E_Function
or else
Types_Correspond
(Etype (P_Prim), Etype (New_E)))
then
return False;
end if;
end if;
Next_Elmt (Prim_Elt);
end loop;
-- If no match found, then the new subprogram does
-- not override in the generic (nor in the instance).
return True;
end;
end if;
else
return False;
end if;
end Is_Non_Overriding_Operation;
------------------------------
-- Make_Inequality_Operator --
------------------------------
-- S is the defining identifier of an equality operator. We build a
-- subprogram declaration with the right signature. This operation is
-- intrinsic, because it is always expanded as the negation of the
-- call to the equality function.
procedure Make_Inequality_Operator (S : Entity_Id) is
Loc : constant Source_Ptr := Sloc (S);
Decl : Node_Id;
Formals : List_Id;
Op_Name : Entity_Id;
A : Entity_Id;
B : Entity_Id;
begin
-- Check that equality was properly defined.
if No (Next_Formal (First_Formal (S))) then
return;
end if;
A := Make_Defining_Identifier (Loc, Chars (First_Formal (S)));
B := Make_Defining_Identifier (Loc,
Chars (Next_Formal (First_Formal (S))));
Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => A,
Parameter_Type =>
New_Reference_To (Etype (First_Formal (S)), Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => B,
Parameter_Type =>
New_Reference_To (Etype (Next_Formal (First_Formal (S))), Loc)));
Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Op_Name,
Parameter_Specifications => Formals,
Subtype_Mark => New_Reference_To (Standard_Boolean, Loc)));
-- Insert inequality right after equality if it is explicit or after
-- the derived type when implicit. These entities are created only
-- for visibility purposes, and eventually replaced in the course of
-- expansion, so they do not need to be attached to the tree and seen
-- by the back-end. Keeping them internal also avoids spurious freezing
-- problems. The parent field is set simply to make analysis safe.
if No (Alias (S)) then
Set_Parent (Decl, Parent (Unit_Declaration_Node (S)));
else
Set_Parent (Decl, Parent (Parent (Etype (First_Formal (S)))));
end if;
Mark_Rewrite_Insertion (Decl);
Set_Is_Intrinsic_Subprogram (Op_Name);
Analyze (Decl);
Set_Has_Completion (Op_Name);
Set_Corresponding_Equality (Op_Name, S);
Set_Is_Abstract (Op_Name, Is_Abstract (S));
end Make_Inequality_Operator;
----------------------
-- May_Need_Actuals --
----------------------
procedure May_Need_Actuals (Fun : Entity_Id) is
F : Entity_Id;
B : Boolean;
begin
F := First_Formal (Fun);
B := True;
while Present (F) loop
if No (Default_Value (F)) then
B := False;
exit;
end if;
Next_Formal (F);
end loop;
Set_Needs_No_Actuals (Fun, B);
end May_Need_Actuals;
---------------------
-- Mode_Conformant --
---------------------
function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
return Result;
end Mode_Conformant;
---------------------------
-- New_Overloaded_Entity --
---------------------------
procedure New_Overloaded_Entity
(S : Entity_Id;
Derived_Type : Entity_Id := Empty)
is
E : Entity_Id := Current_Entity_In_Scope (S);
Prev_Vis : Entity_Id := Empty;
function Is_Private_Declaration (E : Entity_Id) return Boolean;
-- Check that E is declared in the private part of the current package,
-- or in the package body, where it may hide a previous declaration.
-- We can' use In_Private_Part by itself because this flag is also
-- set when freezing entities, so we must examine the place of the
-- declaration in the tree, and recognize wrapper packages as well.
procedure Maybe_Primitive_Operation (Overriding : Boolean := False);
-- If the subprogram being analyzed is a primitive operation of
-- the type of one of its formals, set the corresponding flag.
----------------------------
-- Is_Private_Declaration --
----------------------------
function Is_Private_Declaration (E : Entity_Id) return Boolean is
Priv_Decls : List_Id;
Decl : constant Node_Id := Unit_Declaration_Node (E);
begin
if Is_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
then
Priv_Decls :=
Private_Declarations (
Specification (Unit_Declaration_Node (Current_Scope)));
return In_Package_Body (Current_Scope)
or else List_Containing (Decl) = Priv_Decls
or else (Nkind (Parent (Decl)) = N_Package_Specification
and then not Is_Compilation_Unit (
Defining_Entity (Parent (Decl)))
and then List_Containing (Parent (Parent (Decl)))
= Priv_Decls);
else
return False;
end if;
end Is_Private_Declaration;
-------------------------------
-- Maybe_Primitive_Operation --
-------------------------------
procedure Maybe_Primitive_Operation (Overriding : Boolean := False) is
Formal : Entity_Id;
F_Typ : Entity_Id;
function Visible_Part_Type (T : Entity_Id) return Boolean;
-- Returns true if T is declared in the visible part of
-- the current package scope; otherwise returns false.
-- Assumes that T is declared in a package.
procedure Check_Private_Overriding (T : Entity_Id);
-- Checks that if a primitive abstract subprogram of a visible
-- abstract type is declared in a private part, then it must
-- override an abstract subprogram declared in the visible part.
-- Also checks that if a primitive function with a controlling
-- result is declared in a private part, then it must override
-- a function declared in the visible part.
------------------------------
-- Check_Private_Overriding --
------------------------------
procedure Check_Private_Overriding (T : Entity_Id) is
begin
if Ekind (Current_Scope) = E_Package
and then In_Private_Part (Current_Scope)
and then Visible_Part_Type (T)
and then not In_Instance
then
if Is_Abstract (T)
and then Is_Abstract (S)
and then (not Overriding or else not Is_Abstract (E))
then
Error_Msg_N ("abstract subprograms must be visible "
& "('R'M 3.9.3(10))!", S);
elsif Ekind (S) = E_Function
and then Is_Tagged_Type (T)
and then T = Base_Type (Etype (S))
and then not Overriding
then
Error_Msg_N
("private function with tagged result must"
& " override visible-part function", S);
Error_Msg_N
("\move subprogram to the visible part"
& " ('R'M 3.9.3(10))", S);
end if;
end if;
end Check_Private_Overriding;
-----------------------
-- Visible_Part_Type --
-----------------------
function Visible_Part_Type (T : Entity_Id) return Boolean is
P : Node_Id := Unit_Declaration_Node (Scope (T));
N : Node_Id := First (Visible_Declarations (Specification (P)));
begin
-- If the entity is a private type, then it must be
-- declared in a visible part.
if Ekind (T) in Private_Kind then
return True;
end if;
-- Otherwise, we traverse the visible part looking for its
-- corresponding declaration. We cannot use the declaration
-- node directly because in the private part the entity of a
-- private type is the one in the full view, which does not
-- indicate that it is the completion of something visible.
while Present (N) loop
if Nkind (N) = N_Full_Type_Declaration
and then Present (Defining_Identifier (N))
and then T = Defining_Identifier (N)
then
return True;
elsif (Nkind (N) = N_Private_Type_Declaration
or else
Nkind (N) = N_Private_Extension_Declaration)
and then Present (Defining_Identifier (N))
and then T = Full_View (Defining_Identifier (N))
then
return True;
end if;
Next (N);
end loop;
return False;
end Visible_Part_Type;
-- Start of processing for Maybe_Primitive_Operation
begin
if not Comes_From_Source (S) then
null;
elsif (Ekind (Current_Scope) = E_Package
and then not In_Package_Body (Current_Scope))
or else Overriding
then
if Ekind (S) = E_Function
and then Scope (Base_Type (Etype (S))) = Current_Scope
then
Set_Has_Primitive_Operations (Base_Type (Etype (S)));
Check_Private_Overriding (Base_Type (Etype (S)));
end if;
Formal := First_Formal (S);
while Present (Formal) loop
if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (Etype (Formal));
else
F_Typ := Etype (Formal);
end if;
if Scope (Base_Type (F_Typ)) = Current_Scope then
Set_Has_Primitive_Operations (Base_Type (F_Typ));
Check_Private_Overriding (Base_Type (F_Typ));
end if;
Next_Formal (Formal);
end loop;
end if;
end Maybe_Primitive_Operation;
-- Start of processing for New_Overloaded_Entity
begin
if No (E) then
Enter_Overloaded_Entity (S);
Check_Dispatching_Operation (S, Empty);
Maybe_Primitive_Operation;
elsif not Is_Overloadable (E) then
-- Check for spurious conflict produced by a subprogram that has the
-- same name as that of the enclosing generic package. The conflict
-- occurs within an instance, between the subprogram and the renaming
-- declaration for the package. After the subprogram, the package
-- renaming declaration becomes hidden.
if Ekind (E) = E_Package
and then Present (Renamed_Object (E))
and then Renamed_Object (E) = Current_Scope
and then Nkind (Parent (Renamed_Object (E))) =
N_Package_Specification
and then Present (Generic_Parent (Parent (Renamed_Object (E))))
then
Set_Is_Hidden (E);
Set_Is_Immediately_Visible (E, False);
Enter_Overloaded_Entity (S);
Set_Homonym (S, Homonym (E));
Check_Dispatching_Operation (S, Empty);
-- If the subprogram is implicit it is hidden by the previous
-- declaration. However if it is dispatching, it must appear in
-- the dispatch table anyway, because it can be dispatched to
-- even if it cannot be called directly.
elsif Present (Alias (S))
and then not Comes_From_Source (S)
then
Set_Scope (S, Current_Scope);
if Is_Dispatching_Operation (Alias (S)) then
Check_Dispatching_Operation (S, Empty);
end if;
return;
else
Error_Msg_Sloc := Sloc (E);
Error_Msg_N ("& conflicts with declaration#", S);
-- Useful additional warning.
if Is_Generic_Unit (E) then
Error_Msg_N ("\previous generic unit cannot be overloaded", S);
end if;
return;
end if;
else
-- E exists and is overloadable. Determine whether S is the body
-- of E, a new overloaded entity with a different signature, or
-- an error altogether.
while Present (E) loop
if Scope (E) /= Current_Scope then
null;
elsif Type_Conformant (E, S) then
-- If the old and new entities have the same profile and
-- one is not the body of the other, then this is an error,
-- unless one of them is implicitly declared.
-- There are some cases when both can be implicit, for example
-- when both a literal and a function that overrides it are
-- inherited in a derivation, or when an inhertited operation
-- of a tagged full type overrides the ineherited operation of
-- a private extension. Ada 83 had a special rule for the
-- the literal case. In Ada95, the later implicit operation
-- hides the former, and the literal is always the former.
-- In the odd case where both are derived operations declared
-- at the same point, both operations should be declared,
-- and in that case we bypass the following test and proceed
-- to the next part (this can only occur for certain obscure
-- cases involving homographs in instances and can't occur for
-- dispatching operations ???). Note that the following
-- condition is less than clear. For example, it's not at
-- all clear why there's a test for E_Entry here. ???
if Present (Alias (S))
and then (No (Alias (E))
or else Comes_From_Source (E)
or else Is_Dispatching_Operation (E))
and then
(Ekind (E) = E_Entry
or else Ekind (E) /= E_Enumeration_Literal)
then
-- When an derived operation is overloaded it may be due
-- to the fact that the full view of a private extension
-- re-inherits. It has to be dealt with.
if Is_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
then
Check_Operation_From_Private_View (S, E);
end if;
-- In any case the implicit operation remains hidden by
-- the existing declaration.
return;
-- Within an instance, the renaming declarations for
-- actual subprograms may become ambiguous, but they do
-- not hide each other.
elsif Ekind (E) /= E_Entry
and then not Comes_From_Source (E)
and then not Is_Generic_Instance (E)
and then (Present (Alias (E))
or else Is_Intrinsic_Subprogram (E))
and then (not In_Instance
or else No (Parent (E))
or else Nkind (Unit_Declaration_Node (E)) /=
N_Subprogram_Renaming_Declaration)
then
-- A subprogram child unit is not allowed to override
-- an inherited subprogram (10.1.1(20)).
if Is_Child_Unit (S) then
Error_Msg_N
("child unit overrides inherited subprogram in parent",
S);
return;
end if;
if Is_Non_Overriding_Operation (E, S) then
Enter_Overloaded_Entity (S);
if not Present (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
Check_Dispatching_Operation (S, Empty);
end if;
return;
end if;
-- E is a derived operation or an internal operator which
-- is being overridden. Remove E from further visibility.
-- Furthermore, if E is a dispatching operation, it must be
-- replaced in the list of primitive operations of its type
-- (see Override_Dispatching_Operation).
declare
Prev : Entity_Id;
begin
Prev := First_Entity (Current_Scope);
while Present (Prev)
and then Next_Entity (Prev) /= E
loop
Next_Entity (Prev);
end loop;
-- It is possible for E to be in the current scope and
-- yet not in the entity chain. This can only occur in a
-- generic context where E is an implicit concatenation
-- in the formal part, because in a generic body the
-- entity chain starts with the formals.
pragma Assert
(Present (Prev) or else Chars (E) = Name_Op_Concat);
-- E must be removed both from the entity_list of the
-- current scope, and from the visibility chain
if Debug_Flag_E then
Write_Str ("Override implicit operation ");
Write_Int (Int (E));
Write_Eol;
end if;
-- If E is a predefined concatenation, it stands for four
-- different operations. As a result, a single explicit
-- declaration does not hide it. In a possible ambiguous
-- situation, Disambiguate chooses the user-defined op,
-- so it is correct to retain the previous internal one.
if Chars (E) /= Name_Op_Concat
or else Ekind (E) /= E_Operator
then
-- For nondispatching derived operations that are
-- overridden by a subprogram declared in the private
-- part of a package, we retain the derived subprogram
-- but mark it as not immediately visible. If the
-- derived operation was declared in the visible part
-- then this ensures that it will still be visible
-- outside the package with the proper signature
-- (calls from outside must also be directed to this
-- version rather than the overriding one, unlike the
-- dispatching case). Calls from inside the package
-- will still resolve to the overriding subprogram
-- since the derived one is marked as not visible
-- within the package.
-- If the private operation is dispatching, we achieve
-- the overriding by keeping the implicit operation
-- but setting its alias to be the overring one. In
-- this fashion the proper body is executed in all
-- cases, but the original signature is used outside
-- of the package.
-- If the overriding is not in the private part, we
-- remove the implicit operation altogether.
if Is_Private_Declaration (S) then
if not Is_Dispatching_Operation (E) then
Set_Is_Immediately_Visible (E, False);
else
-- work done in Override_Dispatching_Operation.
null;
end if;
else
-- Find predecessor of E in Homonym chain.
if E = Current_Entity (E) then
Prev_Vis := Empty;
else
Prev_Vis := Current_Entity (E);
while Homonym (Prev_Vis) /= E loop
Prev_Vis := Homonym (Prev_Vis);
end loop;
end if;
if Prev_Vis /= Empty then
-- Skip E in the visibility chain
Set_Homonym (Prev_Vis, Homonym (E));
else
Set_Name_Entity_Id (Chars (E), Homonym (E));
end if;
Set_Next_Entity (Prev, Next_Entity (E));
if No (Next_Entity (Prev)) then
Set_Last_Entity (Current_Scope, Prev);
end if;
end if;
end if;
Enter_Overloaded_Entity (S);
if Is_Dispatching_Operation (E) then
-- An overriding dispatching subprogram inherits
-- the convention of the overridden subprogram
-- (by AI-117).
Set_Convention (S, Convention (E));
Check_Dispatching_Operation (S, E);
else
Check_Dispatching_Operation (S, Empty);
end if;
Maybe_Primitive_Operation (Overriding => True);
goto Check_Inequality;
end;
-- Apparent redeclarations in instances can occur when two
-- formal types get the same actual type. The subprograms in
-- in the instance are legal, even if not callable from the
-- outside. Calls from within are disambiguated elsewhere.
-- For dispatching operations in the visible part, the usual
-- rules apply, and operations with the same profile are not
-- legal (B830001).
elsif (In_Instance_Visible_Part
and then not Is_Dispatching_Operation (E))
or else In_Instance_Not_Visible
then
null;
-- Here we have a real error (identical profile)
else
Error_Msg_Sloc := Sloc (E);
-- Avoid cascaded errors if the entity appears in
-- subsequent calls.
Set_Scope (S, Current_Scope);
Error_Msg_N ("& conflicts with declaration#", S);
if Is_Generic_Instance (S)
and then not Has_Completion (E)
then
Error_Msg_N
("\instantiation cannot provide body for it", S);
end if;
return;
end if;
else
null;
end if;
Prev_Vis := E;
E := Homonym (E);
end loop;
-- On exit, we know that S is a new entity
Enter_Overloaded_Entity (S);
Maybe_Primitive_Operation;
-- If S is a derived operation for an untagged type then
-- by definition it's not a dispatching operation (even
-- if the parent operation was dispatching), so we don't
-- call Check_Dispatching_Operation in that case.
if not Present (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
Check_Dispatching_Operation (S, Empty);
end if;
end if;
-- If this is a user-defined equality operator that is not
-- a derived subprogram, create the corresponding inequality.
-- If the operation is dispatching, the expansion is done
-- elsewhere, and we do not create an explicit inequality
-- operation.
<<Check_Inequality>>
if Chars (S) = Name_Op_Eq
and then Etype (S) = Standard_Boolean
and then Present (Parent (S))
and then not Is_Dispatching_Operation (S)
then
Make_Inequality_Operator (S);
end if;
end New_Overloaded_Entity;
---------------------
-- Process_Formals --
---------------------
procedure Process_Formals
(S : Entity_Id;
T : List_Id;
Related_Nod : Node_Id)
is
Param_Spec : Node_Id;
Formal : Entity_Id;
Formal_Type : Entity_Id;
Default : Node_Id;
Ptype : Entity_Id;
begin
-- In order to prevent premature use of the formals in the same formal
-- part, the Ekind is left undefined until all default expressions are
-- analyzed. The Ekind is established in a separate loop at the end.
Param_Spec := First (T);
while Present (Param_Spec) loop
Formal := Defining_Identifier (Param_Spec);
Enter_Name (Formal);
-- Case of ordinary parameters
if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
Find_Type (Parameter_Type (Param_Spec));
Ptype := Parameter_Type (Param_Spec);
if Ptype = Error then
goto Continue;
end if;
Formal_Type := Entity (Ptype);
if Ekind (Formal_Type) = E_Incomplete_Type
or else (Is_Class_Wide_Type (Formal_Type)
and then Ekind (Root_Type (Formal_Type)) =
E_Incomplete_Type)
then
if Nkind (Parent (T)) /= N_Access_Function_Definition
and then Nkind (Parent (T)) /= N_Access_Procedure_Definition
then
Error_Msg_N ("invalid use of incomplete type", Param_Spec);
end if;
elsif Ekind (Formal_Type) = E_Void then
Error_Msg_NE ("premature use of&",
Parameter_Type (Param_Spec), Formal_Type);
end if;
-- An access formal type
else
Formal_Type :=
Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
end if;
Set_Etype (Formal, Formal_Type);
Default := Expression (Param_Spec);
if Present (Default) then
if Out_Present (Param_Spec) then
Error_Msg_N
("default initialization only allowed for IN parameters",
Param_Spec);
end if;
-- Do the special preanalysis of the expression (see section on
-- "Handling of Default Expressions" in the spec of package Sem).
Analyze_Default_Expression (Default, Formal_Type);
-- Check that the designated type of an access parameter's
-- default is not a class-wide type unless the parameter's
-- designated type is also class-wide.
if Ekind (Formal_Type) = E_Anonymous_Access_Type
and then Is_Class_Wide_Type (Designated_Type (Etype (Default)))
and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
then
Wrong_Type (Default, Formal_Type);
end if;
end if;
<<Continue>>
Next (Param_Spec);
end loop;
-- Now set the kind (mode) of each formal
Param_Spec := First (T);
while Present (Param_Spec) loop
Formal := Defining_Identifier (Param_Spec);
Set_Formal_Mode (Formal);
if Ekind (Formal) = E_In_Parameter then
Set_Default_Value (Formal, Expression (Param_Spec));
if Present (Expression (Param_Spec)) then
Default := Expression (Param_Spec);
if Is_Scalar_Type (Etype (Default)) then
if Nkind
(Parameter_Type (Param_Spec)) /= N_Access_Definition
then
Formal_Type := Entity (Parameter_Type (Param_Spec));
else
Formal_Type := Access_Definition
(Related_Nod, Parameter_Type (Param_Spec));
end if;
Apply_Scalar_Range_Check (Default, Formal_Type);
end if;
end if;
end if;
Next (Param_Spec);
end loop;
end Process_Formals;
-------------------------
-- Set_Actual_Subtypes --
-------------------------
procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Decl : Node_Id;
Formal : Entity_Id;
T : Entity_Id;
First_Stmt : Node_Id := Empty;
AS_Needed : Boolean;
begin
Formal := First_Formal (Subp);
while Present (Formal) loop
T := Etype (Formal);
-- We never need an actual subtype for a constrained formal.
if Is_Constrained (T) then
AS_Needed := False;
-- If we have unknown discriminants, then we do not need an
-- actual subtype, or more accurately we cannot figure it out!
-- Note that all class-wide types have unknown discriminants.
elsif Has_Unknown_Discriminants (T) then
AS_Needed := False;
-- At this stage we have an unconstrained type that may need
-- an actual subtype. For sure the actual subtype is needed
-- if we have an unconstrained array type.
elsif Is_Array_Type (T) then
AS_Needed := True;
-- The only other case which needs an actual subtype is an
-- unconstrained record type which is an IN parameter (we
-- cannot generate actual subtypes for the OUT or IN OUT case,
-- since an assignment can change the discriminant values.
-- However we exclude the case of initialization procedures,
-- since discriminants are handled very specially in this context,
-- see the section entitled "Handling of Discriminants" in Einfo.
-- We also exclude the case of Discrim_SO_Functions (functions
-- used in front end layout mode for size/offset values), since
-- in such functions only discriminants are referenced, and not
-- only are such subtypes not needed, but they cannot always
-- be generated, because of order of elaboration issues.
elsif Is_Record_Type (T)
and then Ekind (Formal) = E_In_Parameter
and then Chars (Formal) /= Name_uInit
and then not Is_Discrim_SO_Function (Subp)
then
AS_Needed := True;
-- All other cases do not need an actual subtype
else
AS_Needed := False;
end if;
-- Generate actual subtypes for unconstrained arrays and
-- unconstrained discriminated records.
if AS_Needed then
Decl := Build_Actual_Subtype (T, Formal);
if Nkind (N) = N_Accept_Statement then
if Present (Handled_Statement_Sequence (N)) then
First_Stmt :=
First (Statements (Handled_Statement_Sequence (N)));
Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
Mark_Rewrite_Insertion (Decl);
else
-- If the accept statement has no body, there will be
-- no reference to the actuals, so no need to compute
-- actual subtypes.
return;
end if;
else
Prepend (Decl, Declarations (N));
Mark_Rewrite_Insertion (Decl);
end if;
Analyze (Decl);
-- We need to freeze manually the generated type when it is
-- inserted anywhere else than in a declarative part.
if Present (First_Stmt) then
Insert_List_Before_And_Analyze (First_Stmt,
Freeze_Entity (Defining_Identifier (Decl), Loc));
end if;
Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
end if;
Next_Formal (Formal);
end loop;
end Set_Actual_Subtypes;
---------------------
-- Set_Formal_Mode --
---------------------
procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
Spec : constant Node_Id := Parent (Formal_Id);
begin
-- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
-- since we ensure that corresponding actuals are always valid at the
-- point of the call.
if Out_Present (Spec) then
if Ekind (Scope (Formal_Id)) = E_Function
or else Ekind (Scope (Formal_Id)) = E_Generic_Function
then
Error_Msg_N ("functions can only have IN parameters", Spec);
Set_Ekind (Formal_Id, E_In_Parameter);
elsif In_Present (Spec) then
Set_Ekind (Formal_Id, E_In_Out_Parameter);
else
Set_Ekind (Formal_Id, E_Out_Parameter);
Set_Not_Source_Assigned (Formal_Id);
end if;
else
Set_Ekind (Formal_Id, E_In_Parameter);
end if;
Set_Mechanism (Formal_Id, Default_Mechanism);
Set_Formal_Validity (Formal_Id);
end Set_Formal_Mode;
-------------------------
-- Set_Formal_Validity --
-------------------------
procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
begin
-- If in full validity checking mode, then we can assume that
-- an IN or IN OUT parameter is valid (see Exp_Ch5.Expand_Call)
if not Validity_Checks_On then
return;
elsif Ekind (Formal_Id) = E_In_Parameter
and then Validity_Check_In_Params
then
Set_Is_Known_Valid (Formal_Id, True);
elsif Ekind (Formal_Id) = E_In_Out_Parameter
and then Validity_Check_In_Out_Params
then
Set_Is_Known_Valid (Formal_Id, True);
end if;
end Set_Formal_Validity;
------------------------
-- Subtype_Conformant --
------------------------
function Subtype_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result);
return Result;
end Subtype_Conformant;
---------------------
-- Type_Conformant --
---------------------
function Type_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Type_Conformant, False, Result);
return Result;
end Type_Conformant;
-------------------------------
-- Valid_Operator_Definition --
-------------------------------
procedure Valid_Operator_Definition (Designator : Entity_Id) is
N : Integer := 0;
F : Entity_Id;
Id : constant Name_Id := Chars (Designator);
N_OK : Boolean;
begin
F := First_Formal (Designator);
while Present (F) loop
N := N + 1;
if Present (Default_Value (F)) then
Error_Msg_N
("default values not allowed for operator parameters",
Parent (F));
end if;
Next_Formal (F);
end loop;
-- Verify that user-defined operators have proper number of arguments
-- First case of operators which can only be unary
if Id = Name_Op_Not
or else Id = Name_Op_Abs
then
N_OK := (N = 1);
-- Case of operators which can be unary or binary
elsif Id = Name_Op_Add
or Id = Name_Op_Subtract
then
N_OK := (N in 1 .. 2);
-- All other operators can only be binary
else
N_OK := (N = 2);
end if;
if not N_OK then
Error_Msg_N
("incorrect number of arguments for operator", Designator);
end if;
if Id = Name_Op_Ne
and then Base_Type (Etype (Designator)) = Standard_Boolean
and then not Is_Intrinsic_Subprogram (Designator)
then
Error_Msg_N
("explicit definition of inequality not allowed", Designator);
end if;
end Valid_Operator_Definition;
end Sem_Ch6;