-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2011, 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- --
with Einfo; use Einfo;
with Errout; use Errout;
with Elists; use Elists;
+with Exp_Aggr; use Exp_Aggr;
with Exp_Atag; use Exp_Atag;
with Exp_Ch2; use Exp_Ch2;
with Exp_Ch3; use Exp_Ch3;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
+with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with Validsw; use Validsw;
-- along directly to the build-in-place function. Finally, if Return_Object
-- is empty, then pass a null literal as the actual.
- procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Alloc_Form : BIP_Allocation_Form := Unspecified;
- Alloc_Form_Exp : Node_Id := Empty);
- -- Ada 2005 (AI-318-02): Add an actual indicating the form of allocation,
- -- if any, to be done by a build-in-place function. If Alloc_Form_Exp is
- -- present, then use it, otherwise pass a literal corresponding to the
- -- Alloc_Form parameter (which must not be Unspecified in that case).
-
- procedure Add_Extra_Actual_To_Call
- (Subprogram_Call : Node_Id;
- Extra_Formal : Entity_Id;
- Extra_Actual : Node_Id);
- -- Adds Extra_Actual as a named parameter association for the formal
- -- Extra_Formal in Subprogram_Call.
-
- procedure Add_Final_List_Actual_To_Build_In_Place_Call
- (Function_Call : Node_Id;
- Function_Id : Entity_Id;
- Acc_Type : Entity_Id;
- Sel_Comp : Node_Id := Empty);
- -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type has
- -- controlled parts, add an actual parameter that is a pointer to
- -- appropriate finalization list. The finalization list is that of the
- -- current scope, except for "new Acc'(F(...))" in which case it's the
- -- finalization list of the access type returned by the allocator. Acc_Type
- -- is that type in the allocator case; Empty otherwise. If Sel_Comp is
- -- not Empty, then it denotes a selected component and the finalization
- -- list is obtained from the _controller list of the prefix object.
+ Alloc_Form_Exp : Node_Id := Empty;
+ Pool_Actual : Node_Id := Make_Null (No_Location));
+ -- Ada 2005 (AI-318-02): Add the actuals needed for a build-in-place
+ -- function call that returns a caller-unknown-size result (BIP_Alloc_Form
+ -- and BIP_Storage_Pool). If Alloc_Form_Exp is present, then use it,
+ -- otherwise pass a literal corresponding to the Alloc_Form parameter
+ -- (which must not be Unspecified in that case). Pool_Actual is the
+ -- parameter to pass to BIP_Storage_Pool.
+
+ procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
+ (Func_Call : Node_Id;
+ Func_Id : Entity_Id;
+ Ptr_Typ : Entity_Id := Empty;
+ Master_Exp : Node_Id := Empty);
+ -- Ada 2005 (AI-318-02): If the result type of a build-in-place call needs
+ -- finalization actions, add an actual parameter which is a pointer to the
+ -- finalization master of the caller. If Master_Exp is not Empty, then that
+ -- will be passed as the actual. Otherwise, if Ptr_Typ is left Empty, this
+ -- will result in an automatic "null" value for the actual.
procedure Add_Task_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
-- expression to pass for the master. In most cases, this is the current
-- master (_master). The two exceptions are: If the function call is the
-- initialization expression for an allocator, we pass the master of the
- -- access type. If the function call is the initialization expression for
- -- a return object, we pass along the master passed in by the caller. The
- -- activation chain to pass is always the local one.
+ -- access type. If the function call is the initialization expression for a
+ -- return object, we pass along the master passed in by the caller. The
+ -- activation chain to pass is always the local one. Note: Master_Actual
+ -- can be Empty, but only if there are no tasks.
procedure Check_Overriding_Operation (Subp : Entity_Id);
-- Subp is a dispatching operation. Check whether it may override an
-- the values are not changed for the call, we know immediately that
-- we have an infinite recursion.
- procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
- -- For each actual of an in-out or out parameter which is a numeric
- -- (view) conversion of the form T (A), where A denotes a variable,
- -- we insert the declaration:
- --
- -- Temp : T[ := T (A)];
- --
- -- prior to the call. Then we replace the actual with a reference to Temp,
- -- and append the assignment:
- --
- -- A := TypeA (Temp);
- --
- -- after the call. Here TypeA is the actual type of variable A. For out
- -- parameters, the initial declaration has no expression. If A is not an
- -- entity name, we generate instead:
- --
- -- Var : TypeA renames A;
- -- Temp : T := Var; -- omitting expression for out parameter.
- -- ...
- -- Var := TypeA (Temp);
- --
- -- For other in-out parameters, we emit the required constraint checks
- -- before and/or after the call.
- --
- -- For all parameter modes, actuals that denote components and slices of
- -- packed arrays are expanded into suitable temporaries.
- --
- -- For non-scalar objects that are possibly unaligned, add call by copy
- -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
+ procedure Expand_Ctrl_Function_Call (N : Node_Id);
+ -- N is a function call which returns a controlled object. Transform the
+ -- call into a temporary which retrieves the returned object from the
+ -- secondary stack using 'reference.
procedure Expand_Inlined_Call
(N : Node_Id;
-- expressions in the body must be converted to the desired type (which
-- is simply not noted in the tree without inline expansion).
+ procedure Expand_Non_Function_Return (N : Node_Id);
+ -- Called by Expand_N_Simple_Return_Statement in case we're returning from
+ -- a procedure body, entry body, accept statement, or extended return
+ -- statement. Note that all non-function returns are simple return
+ -- statements.
+
function Expand_Protected_Object_Reference
(N : Node_Id;
Scop : Entity_Id) return Node_Id;
-- reference to the object itself, and the call becomes a call to the
-- corresponding protected subprogram.
- function Is_Null_Procedure (Subp : Entity_Id) return Boolean;
- -- Predicate to recognize stubbed procedures and null procedures, which
- -- can be inlined unconditionally in all cases.
+ function Has_Unconstrained_Access_Discriminants
+ (Subtyp : Entity_Id) return Boolean;
+ -- Returns True if the given subtype is unconstrained and has one
+ -- or more access discriminants.
+
+ procedure Expand_Simple_Function_Return (N : Node_Id);
+ -- Expand simple return from function. In the case where we are returning
+ -- from a function body this is called by Expand_N_Simple_Return_Statement.
----------------------------------------------
-- Add_Access_Actual_To_Build_In_Place_Call --
Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
end Add_Access_Actual_To_Build_In_Place_Call;
- --------------------------------------------------
- -- Add_Alloc_Form_Actual_To_Build_In_Place_Call --
- --------------------------------------------------
+ ------------------------------------------------------
+ -- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
+ ------------------------------------------------------
- procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Alloc_Form : BIP_Allocation_Form := Unspecified;
- Alloc_Form_Exp : Node_Id := Empty)
+ Alloc_Form_Exp : Node_Id := Empty;
+ Pool_Actual : Node_Id := Make_Null (No_Location))
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Alloc_Form_Actual : Node_Id;
Alloc_Form_Formal : Node_Id;
+ Pool_Formal : Node_Id;
begin
-- The allocation form generally doesn't need to be passed in the case
Add_Extra_Actual_To_Call
(Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
- end Add_Alloc_Form_Actual_To_Build_In_Place_Call;
+
+ -- Pass the Storage_Pool parameter. This parameter is omitted on
+ -- .NET/JVM/ZFP as those targets do not support pools.
+
+ if VM_Target = No_VM
+ and then RTE_Available (RE_Root_Storage_Pool_Ptr)
+ then
+ Pool_Formal := Build_In_Place_Formal (Function_Id, BIP_Storage_Pool);
+ Analyze_And_Resolve (Pool_Actual, Etype (Pool_Formal));
+ Add_Extra_Actual_To_Call
+ (Function_Call, Pool_Formal, Pool_Actual);
+ end if;
+ end Add_Unconstrained_Actuals_To_Build_In_Place_Call;
+
+ -----------------------------------------------------------
+ -- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
+ -----------------------------------------------------------
+
+ procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
+ (Func_Call : Node_Id;
+ Func_Id : Entity_Id;
+ Ptr_Typ : Entity_Id := Empty;
+ Master_Exp : Node_Id := Empty)
+ is
+ begin
+ if not Needs_BIP_Finalization_Master (Func_Id) then
+ return;
+ end if;
+
+ declare
+ Formal : constant Entity_Id :=
+ Build_In_Place_Formal (Func_Id, BIP_Finalization_Master);
+ Loc : constant Source_Ptr := Sloc (Func_Call);
+
+ Actual : Node_Id;
+ Desig_Typ : Entity_Id;
+
+ begin
+ -- If there is a finalization master actual, such as the implicit
+ -- finalization master of an enclosing build-in-place function,
+ -- then this must be added as an extra actual of the call.
+
+ if Present (Master_Exp) then
+ Actual := Master_Exp;
+
+ -- Case where the context does not require an actual master
+
+ elsif No (Ptr_Typ) then
+ Actual := Make_Null (Loc);
+
+ else
+ Desig_Typ := Directly_Designated_Type (Ptr_Typ);
+
+ -- Check for a library-level access type whose designated type has
+ -- supressed finalization. Such an access types lack a master.
+ -- Pass a null actual to the callee in order to signal a missing
+ -- master.
+
+ if Is_Library_Level_Entity (Ptr_Typ)
+ and then Finalize_Storage_Only (Desig_Typ)
+ then
+ Actual := Make_Null (Loc);
+
+ -- Types in need of finalization actions
+
+ elsif Needs_Finalization (Desig_Typ) then
+
+ -- The general mechanism of creating finalization masters for
+ -- anonymous access types is disabled by default, otherwise
+ -- finalization masters will pop all over the place. Such types
+ -- use context-specific masters.
+
+ if Ekind (Ptr_Typ) = E_Anonymous_Access_Type
+ and then No (Finalization_Master (Ptr_Typ))
+ then
+ Build_Finalization_Master
+ (Typ => Ptr_Typ,
+ Ins_Node => Associated_Node_For_Itype (Ptr_Typ),
+ Encl_Scope => Scope (Ptr_Typ));
+ end if;
+
+ -- Access-to-controlled types should always have a master
+
+ pragma Assert (Present (Finalization_Master (Ptr_Typ)));
+
+ Actual :=
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Reference_To (Finalization_Master (Ptr_Typ), Loc),
+ Attribute_Name => Name_Unrestricted_Access);
+
+ -- Tagged types
+
+ else
+ Actual := Make_Null (Loc);
+ end if;
+ end if;
+
+ Analyze_And_Resolve (Actual, Etype (Formal));
+
+ -- Build the parameter association for the new actual and add it to
+ -- the end of the function's actuals.
+
+ Add_Extra_Actual_To_Call (Func_Call, Formal, Actual);
+ end;
+ end Add_Finalization_Master_Actual_To_Build_In_Place_Call;
------------------------------
-- Add_Extra_Actual_To_Call --
end if;
end Add_Extra_Actual_To_Call;
- --------------------------------------------------
- -- Add_Final_List_Actual_To_Build_In_Place_Call --
- --------------------------------------------------
-
- procedure Add_Final_List_Actual_To_Build_In_Place_Call
- (Function_Call : Node_Id;
- Function_Id : Entity_Id;
- Acc_Type : Entity_Id;
- Sel_Comp : Node_Id := Empty)
- is
- Loc : constant Source_Ptr := Sloc (Function_Call);
- Final_List : Node_Id;
- Final_List_Actual : Node_Id;
- Final_List_Formal : Node_Id;
- Is_Ctrl_Result : constant Boolean :=
- Needs_Finalization
- (Underlying_Type (Etype (Function_Id)));
-
- begin
- -- No such extra parameter is needed if there are no controlled parts.
- -- The test for Needs_Finalization accounts for class-wide results
- -- (which potentially have controlled parts, even if the root type
- -- doesn't), and the test for a tagged result type is needed because
- -- calls to such a function can in general occur in dispatching
- -- contexts, which must be treated the same as a call to class-wide
- -- functions. Both of these situations require that a finalization list
- -- be passed.
-
- if not Needs_BIP_Final_List (Function_Id) then
- return;
- end if;
-
- -- Locate implicit finalization list parameter in the called function
-
- Final_List_Formal := Build_In_Place_Formal (Function_Id, BIP_Final_List);
-
- -- Create the actual which is a pointer to the appropriate finalization
- -- list. Acc_Type is present if and only if this call is the
- -- initialization of an allocator. Use the Current_Scope or the
- -- Acc_Type as appropriate.
-
- if Present (Acc_Type)
- and then (Ekind (Acc_Type) = E_Anonymous_Access_Type
- or else
- Present (Associated_Final_Chain (Base_Type (Acc_Type))))
- then
- Final_List := Find_Final_List (Acc_Type);
-
- -- If Sel_Comp is present and the function result is controlled, then
- -- the finalization list will be obtained from the _controller list of
- -- the selected component's prefix object.
-
- elsif Present (Sel_Comp) and then Is_Ctrl_Result then
- Final_List := Find_Final_List (Current_Scope, Sel_Comp);
-
- else
- Final_List := Find_Final_List (Current_Scope);
- end if;
-
- Final_List_Actual :=
- Make_Attribute_Reference (Loc,
- Prefix => Final_List,
- Attribute_Name => Name_Unrestricted_Access);
-
- Analyze_And_Resolve (Final_List_Actual, Etype (Final_List_Formal));
-
- -- Build the parameter association for the new actual and add it to the
- -- end of the function's actuals.
-
- Add_Extra_Actual_To_Call
- (Function_Call, Final_List_Formal, Final_List_Actual);
- end Add_Final_List_Actual_To_Build_In_Place_Call;
-
---------------------------------------------
-- Add_Task_Actuals_To_Build_In_Place_Call --
---------------------------------------------
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Master_Actual : Node_Id)
- -- Note: Master_Actual can be Empty, but only if there are no tasks
is
- Loc : constant Source_Ptr := Sloc (Function_Call);
+ Loc : constant Source_Ptr := Sloc (Function_Call);
+ Result_Subt : constant Entity_Id :=
+ Available_View (Etype (Function_Id));
+ Actual : Node_Id;
+ Chain_Actual : Node_Id;
+ Chain_Formal : Node_Id;
+ Master_Formal : Node_Id;
begin
-- No such extra parameters are needed if there are no tasks
- if not Has_Task (Etype (Function_Id)) then
+ if not Has_Task (Result_Subt) then
return;
end if;
- -- The master
+ Actual := Master_Actual;
- declare
- Master_Formal : Node_Id;
- begin
- -- Locate implicit master parameter in the called function
+ -- Use a dummy _master actual in case of No_Task_Hierarchy
- Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Master);
+ if Restriction_Active (No_Task_Hierarchy) then
+ Actual := New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc);
- Analyze_And_Resolve (Master_Actual, Etype (Master_Formal));
+ -- In the case where we use the master associated with an access type,
+ -- the actual is an entity and requires an explicit reference.
- -- Build the parameter association for the new actual and add it to
- -- the end of the function's actuals.
+ elsif Nkind (Actual) = N_Defining_Identifier then
+ Actual := New_Reference_To (Actual, Loc);
+ end if;
- Add_Extra_Actual_To_Call
- (Function_Call, Master_Formal, Master_Actual);
- end;
+ -- Locate the implicit master parameter in the called function
- -- The activation chain
+ Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Task_Master);
+ Analyze_And_Resolve (Actual, Etype (Master_Formal));
- declare
- Activation_Chain_Actual : Node_Id;
- Activation_Chain_Formal : Node_Id;
+ -- Build the parameter association for the new actual and add it to the
+ -- end of the function's actuals.
- begin
- -- Locate implicit activation chain parameter in the called function
+ Add_Extra_Actual_To_Call (Function_Call, Master_Formal, Actual);
+
+ -- Locate the implicit activation chain parameter in the called function
- Activation_Chain_Formal := Build_In_Place_Formal
- (Function_Id, BIP_Activation_Chain);
+ Chain_Formal :=
+ Build_In_Place_Formal (Function_Id, BIP_Activation_Chain);
- -- Create the actual which is a pointer to the current activation
- -- chain
+ -- Create the actual which is a pointer to the current activation chain
- Activation_Chain_Actual :=
- Make_Attribute_Reference (Loc,
- Prefix => Make_Identifier (Loc, Name_uChain),
- Attribute_Name => Name_Unrestricted_Access);
+ Chain_Actual :=
+ Make_Attribute_Reference (Loc,
+ Prefix => Make_Identifier (Loc, Name_uChain),
+ Attribute_Name => Name_Unrestricted_Access);
- Analyze_And_Resolve
- (Activation_Chain_Actual, Etype (Activation_Chain_Formal));
+ Analyze_And_Resolve (Chain_Actual, Etype (Chain_Formal));
- -- Build the parameter association for the new actual and add it to
- -- the end of the function's actuals.
+ -- Build the parameter association for the new actual and add it to the
+ -- end of the function's actuals.
- Add_Extra_Actual_To_Call
- (Function_Call, Activation_Chain_Formal, Activation_Chain_Actual);
- end;
+ Add_Extra_Actual_To_Call (Function_Call, Chain_Formal, Chain_Actual);
end Add_Task_Actuals_To_Build_In_Place_Call;
-----------------------
function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
begin
case Kind is
- when BIP_Alloc_Form =>
+ when BIP_Alloc_Form =>
return "BIPalloc";
- when BIP_Final_List =>
- return "BIPfinallist";
- when BIP_Master =>
- return "BIPmaster";
- when BIP_Activation_Chain =>
+ when BIP_Storage_Pool =>
+ return "BIPstoragepool";
+ when BIP_Finalization_Master =>
+ return "BIPfinalizationmaster";
+ when BIP_Task_Master =>
+ return "BIPtaskmaster";
+ when BIP_Activation_Chain =>
return "BIPactivationchain";
- when BIP_Object_Access =>
+ when BIP_Object_Access =>
return "BIPaccess";
end case;
end BIP_Formal_Suffix;
(Func : Entity_Id;
Kind : BIP_Formal_Kind) return Entity_Id
is
+ Formal_Name : constant Name_Id :=
+ New_External_Name
+ (Chars (Func), BIP_Formal_Suffix (Kind));
Extra_Formal : Entity_Id := Extra_Formals (Func);
begin
-- Maybe it would be better for each implicit formal of a build-in-place
-- function to have a flag or a Uint attribute to identify it. ???
+ -- The return type in the function declaration may have been a limited
+ -- view, and the extra formals for the function were not generated at
+ -- that point. At the point of call the full view must be available and
+ -- the extra formals can be created.
+
+ if No (Extra_Formal) then
+ Create_Extra_Formals (Func);
+ Extra_Formal := Extra_Formals (Func);
+ end if;
+
loop
pragma Assert (Present (Extra_Formal));
- exit when
- Chars (Extra_Formal) =
- New_External_Name (Chars (Func), BIP_Formal_Suffix (Kind));
+ exit when Chars (Extra_Formal) = Formal_Name;
+
Next_Formal_With_Extras (Extra_Formal);
end loop;
if Is_Derived_Type (Typ)
and then not Is_Private_Type (Typ)
and then In_Open_Scopes (Scope (Etype (Typ)))
- and then Typ = Base_Type (Typ)
+ and then Is_Base_Type (Typ)
then
-- Subp overrides an inherited private operation if there is an
-- inherited operation with a different name than Subp (see
Set_Assignment_OK (Lhs);
- Append_To (Post_Call,
- Make_Assignment_Statement (Loc,
- Name => Lhs,
- Expression => Expr));
+ if Is_Access_Type (E_Formal)
+ and then Is_Entity_Name (Lhs)
+ and then
+ Present (Effective_Extra_Accessibility (Entity (Lhs)))
+ then
+ -- Copyback target is an Ada 2012 stand-alone object
+ -- of an anonymous access type
+
+ pragma Assert (Ada_Version >= Ada_2012);
+
+ if Type_Access_Level (E_Formal) >
+ Object_Access_Level (Lhs)
+ then
+ Append_To (Post_Call,
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Accessibility_Check_Failed));
+ end if;
+
+ Append_To (Post_Call,
+ Make_Assignment_Statement (Loc,
+ Name => Lhs,
+ Expression => Expr));
+
+ -- We would like to somehow suppress generation of the
+ -- extra_accessibility assignment generated by the expansion
+ -- of the above assignment statement. It's not a correctness
+ -- issue because the following assignment renders it dead,
+ -- but generating back-to-back assignments to the same
+ -- target is undesirable. ???
+
+ Append_To (Post_Call,
+ Make_Assignment_Statement (Loc,
+ Name => New_Occurrence_Of (
+ Effective_Extra_Accessibility (Entity (Lhs)), Loc),
+ Expression => Make_Integer_Literal (Loc,
+ Type_Access_Level (E_Formal))));
+
+ else
+ Append_To (Post_Call,
+ Make_Assignment_Statement (Loc,
+ Name => Lhs,
+ Expression => Expr));
+ end if;
end;
end if;
end Add_Call_By_Copy_Code;
-- functions that are treated as build-in-place to include other
-- composite result types.
- if Ada_Version >= Ada_05
- and then Is_Build_In_Place_Function_Call (Actual)
- then
+ if Is_Build_In_Place_Function_Call (Actual) then
Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
end if;
elsif Is_Possibly_Unaligned_Slice (Actual) then
Add_Call_By_Copy_Code;
+
+ -- An unusual case: a current instance of an enclosing task can be
+ -- an actual, and must be replaced by a reference to self.
+
+ elsif Is_Entity_Name (Actual)
+ and then Is_Task_Type (Entity (Actual))
+ then
+ if In_Open_Scopes (Entity (Actual)) then
+ Rewrite (Actual,
+ (Make_Function_Call (Loc,
+ Name => New_Reference_To (RTE (RE_Self), Loc))));
+ Analyze (Actual);
+
+ -- A task type cannot otherwise appear as an actual
+
+ else
+ raise Program_Error;
+ end if;
end if;
end if;
if not Is_Empty_List (Post_Call) then
- -- If call is not a list member, it must be the triggering statement
- -- of a triggering alternative or an entry call alternative, and we
- -- can add the post call stuff to the corresponding statement list.
+ -- Cases where the call is not a member of a statement list
if not Is_List_Member (N) then
declare
- P : constant Node_Id := Parent (N);
+ P : Node_Id := Parent (N);
begin
- pragma Assert (Nkind_In (P, N_Triggering_Alternative,
- N_Entry_Call_Alternative));
+ -- In Ada 2012 the call may be a function call in an expression
+ -- (since OUT and IN OUT parameters are now allowed for such
+ -- calls. The write-back of (in)-out parameters is handled
+ -- by the back-end, but the constraint checks generated when
+ -- subtypes of formal and actual don't match must be inserted
+ -- in the form of assignments, at the nearest point after the
+ -- declaration or statement that contains the call.
+
+ if Ada_Version >= Ada_2012
+ and then Nkind (N) = N_Function_Call
+ then
+ while Nkind (P) not in N_Declaration
+ and then
+ Nkind (P) not in N_Statement_Other_Than_Procedure_Call
+ loop
+ P := Parent (P);
+ end loop;
+
+ Insert_Actions_After (P, Post_Call);
+
+ -- If not the special Ada 2012 case of a function call, then
+ -- we must have the triggering statement of a triggering
+ -- alternative or an entry call alternative, and we can add
+ -- the post call stuff to the corresponding statement list.
- if Is_Non_Empty_List (Statements (P)) then
- Insert_List_Before_And_Analyze
- (First (Statements (P)), Post_Call);
else
- Set_Statements (P, Post_Call);
+ pragma Assert (Nkind_In (P, N_Triggering_Alternative,
+ N_Entry_Call_Alternative));
+
+ if Is_Non_Empty_List (Statements (P)) then
+ Insert_List_Before_And_Analyze
+ (First (Statements (P)), Post_Call);
+ else
+ Set_Statements (P, Post_Call);
+ end if;
end if;
+
end;
-- Otherwise, normal case where N is in a statement sequence,
procedure Expand_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
+ Call_Node : Node_Id := N;
Extra_Actuals : List_Id := No_List;
Prev : Node_Id := Empty;
-- convoluted tree traversal before setting the proper subprogram to be
-- called.
+ function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean;
+ -- Determine if Subp denotes a non-dispatching call to a Deep routine
+
+ function New_Value (From : Node_Id) return Node_Id;
+ -- From is the original Expression. New_Value is equivalent to a call
+ -- to Duplicate_Subexpr with an explicit dereference when From is an
+ -- access parameter.
+
--------------------------
-- Add_Actual_Parameter --
--------------------------
if No (Prev) or else
Nkind (Parent (Prev)) /= N_Parameter_Association
then
- Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
- Set_First_Named_Actual (N, Actual_Expr);
+ Set_Next_Named_Actual
+ (Insert_Param, First_Named_Actual (Call_Node));
+ Set_First_Named_Actual (Call_Node, Actual_Expr);
if No (Prev) then
- if No (Parameter_Associations (N)) then
- Set_Parameter_Associations (N, New_List);
- Append (Insert_Param, Parameter_Associations (N));
+ if No (Parameter_Associations (Call_Node)) then
+ Set_Parameter_Associations (Call_Node, New_List);
end if;
+
+ Append (Insert_Param, Parameter_Associations (Call_Node));
+
else
Insert_After (Prev, Insert_Param);
end if;
Set_Next_Named_Actual
(Insert_Param, Next_Named_Actual (Parent (Prev)));
Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
- Append (Insert_Param, Parameter_Associations (N));
+ Append (Insert_Param, Parameter_Associations (Call_Node));
end if;
Prev := Actual_Expr;
begin
if Extra_Actuals = No_List then
Extra_Actuals := New_List;
- Set_Parent (Extra_Actuals, N);
+ Set_Parent (Extra_Actuals, Call_Node);
end if;
Append_To (Extra_Actuals,
Make_Parameter_Association (Loc,
- Explicit_Actual_Parameter => Expr,
- Selector_Name =>
- Make_Identifier (Loc, Chars (EF))));
+ Selector_Name => Make_Identifier (Loc, Chars (EF)),
+ Explicit_Actual_Parameter => Expr));
Analyze_And_Resolve (Expr, Etype (EF));
- if Nkind (N) = N_Function_Call then
+ if Nkind (Call_Node) = N_Function_Call then
Set_Is_Accessibility_Actual (Parent (Expr));
end if;
end Add_Extra_Actual;
raise Program_Error;
end Inherited_From_Formal;
+ -------------------------
+ -- Is_Direct_Deep_Call --
+ -------------------------
+
+ function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean is
+ begin
+ if Is_TSS (Subp, TSS_Deep_Adjust)
+ or else Is_TSS (Subp, TSS_Deep_Finalize)
+ or else Is_TSS (Subp, TSS_Deep_Initialize)
+ then
+ declare
+ Actual : Node_Id;
+ Formal : Node_Id;
+
+ begin
+ Actual := First (Parameter_Associations (N));
+ Formal := First_Formal (Subp);
+ while Present (Actual)
+ and then Present (Formal)
+ loop
+ if Nkind (Actual) = N_Identifier
+ and then Is_Controlling_Actual (Actual)
+ and then Etype (Actual) = Etype (Formal)
+ then
+ return True;
+ end if;
+
+ Next (Actual);
+ Next_Formal (Formal);
+ end loop;
+ end;
+ end if;
+
+ return False;
+ end Is_Direct_Deep_Call;
+
+ ---------------
+ -- New_Value --
+ ---------------
+
+ function New_Value (From : Node_Id) return Node_Id is
+ Res : constant Node_Id := Duplicate_Subexpr (From);
+ begin
+ if Is_Access_Type (Etype (From)) then
+ return
+ Make_Explicit_Dereference (Sloc (From),
+ Prefix => Res);
+ else
+ return Res;
+ end if;
+ end New_Value;
+
-- Local variables
- Remote : constant Boolean := Is_Remote_Call (N);
+ Curr_S : constant Entity_Id := Current_Scope;
+ Remote : constant Boolean := Is_Remote_Call (Call_Node);
Actual : Node_Id;
Formal : Entity_Id;
Orig_Subp : Entity_Id := Empty;
begin
-- Ignore if previous error
- if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
+ if Nkind (Call_Node) in N_Has_Etype
+ and then Etype (Call_Node) = Any_Type
+ then
return;
end if;
-- Call using access to subprogram with explicit dereference
- if Nkind (Name (N)) = N_Explicit_Dereference then
- Subp := Etype (Name (N));
+ if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
+ Subp := Etype (Name (Call_Node));
Parent_Subp := Empty;
-- Case of call to simple entry, where the Name is a selected component
-- whose prefix is the task, and whose selector name is the entry name
- elsif Nkind (Name (N)) = N_Selected_Component then
- Subp := Entity (Selector_Name (Name (N)));
+ elsif Nkind (Name (Call_Node)) = N_Selected_Component then
+ Subp := Entity (Selector_Name (Name (Call_Node)));
Parent_Subp := Empty;
-- Case of call to member of entry family, where Name is an indexed
-- component, with the prefix being a selected component giving the
-- task and entry family name, and the index being the entry index.
- elsif Nkind (Name (N)) = N_Indexed_Component then
- Subp := Entity (Selector_Name (Prefix (Name (N))));
+ elsif Nkind (Name (Call_Node)) = N_Indexed_Component then
+ Subp := Entity (Selector_Name (Prefix (Name (Call_Node))));
Parent_Subp := Empty;
-- Normal case
else
- Subp := Entity (Name (N));
+ Subp := Entity (Name (Call_Node));
Parent_Subp := Alias (Subp);
-- Replace call to Raise_Exception by call to Raise_Exception_Always
and then RTE_Available (RE_Raise_Exception_Always)
then
declare
- FA : constant Node_Id := Original_Node (First_Actual (N));
+ FA : constant Node_Id :=
+ Original_Node (First_Actual (Call_Node));
begin
-- The case we catch is where the first argument is obtained
and then Attribute_Name (FA) = Name_Identity
then
Subp := RTE (RE_Raise_Exception_Always);
- Set_Name (N, New_Occurrence_Of (Subp, Loc));
+ Set_Name (Call_Node, New_Occurrence_Of (Subp, Loc));
end if;
end;
end if;
end if;
end if;
+ -- Detect the following code in System.Finalization_Masters only on
+ -- .NET/JVM targets:
+ --
+ -- procedure Finalize (Master : in out Finalization_Master) is
+ -- begin
+ -- . . .
+ -- begin
+ -- Finalize (Curr_Ptr.all);
+ --
+ -- Since .NET/JVM compilers lack address arithmetic and Deep_Finalize
+ -- cannot be named in library or user code, the compiler has to install
+ -- a kludge and transform the call to Finalize into Deep_Finalize.
+
+ if VM_Target /= No_VM
+ and then Chars (Subp) = Name_Finalize
+ and then Ekind (Curr_S) = E_Block
+ and then Ekind (Scope (Curr_S)) = E_Procedure
+ and then Chars (Scope (Curr_S)) = Name_Finalize
+ and then Etype (First_Formal (Scope (Curr_S))) =
+ RTE (RE_Finalization_Master)
+ then
+ declare
+ Deep_Fin : constant Entity_Id :=
+ Find_Prim_Op (RTE (RE_Root_Controlled),
+ TSS_Deep_Finalize);
+ begin
+ -- Since Root_Controlled is a tagged type, the compiler should
+ -- always generate Deep_Finalize for it.
+
+ pragma Assert (Present (Deep_Fin));
+
+ -- Generate:
+ -- Deep_Finalize (Curr_Ptr.all);
+
+ Rewrite (N,
+ Make_Procedure_Call_Statement (Loc,
+ Name =>
+ New_Reference_To (Deep_Fin, Loc),
+ Parameter_Associations =>
+ New_Copy_List_Tree (Parameter_Associations (N))));
+
+ Analyze (N);
+ return;
+ end;
+ end if;
+
-- Ada 2005 (AI-345): We have a procedure call as a triggering
-- alternative in an asynchronous select or as an entry call in
-- a conditional or timed select. Check whether the procedure call
-- is a renaming of an entry and rewrite it as an entry call.
- if Ada_Version >= Ada_05
- and then Nkind (N) = N_Procedure_Call_Statement
+ if Ada_Version >= Ada_2005
+ and then Nkind (Call_Node) = N_Procedure_Call_Statement
and then
- ((Nkind (Parent (N)) = N_Triggering_Alternative
- and then Triggering_Statement (Parent (N)) = N)
+ ((Nkind (Parent (Call_Node)) = N_Triggering_Alternative
+ and then Triggering_Statement (Parent (Call_Node)) = Call_Node)
or else
- (Nkind (Parent (N)) = N_Entry_Call_Alternative
- and then Entry_Call_Statement (Parent (N)) = N))
+ (Nkind (Parent (Call_Node)) = N_Entry_Call_Alternative
+ and then Entry_Call_Statement (Parent (Call_Node)) = Call_Node))
then
declare
Ren_Decl : Node_Id;
Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
- Rewrite (N,
+ Rewrite (Call_Node,
Make_Entry_Call_Statement (Loc,
Name =>
New_Copy_Tree (Name (Ren_Decl)),
Parameter_Associations =>
- New_Copy_List_Tree (Parameter_Associations (N))));
+ New_Copy_List_Tree
+ (Parameter_Associations (Call_Node))));
return;
end if;
-- as we go through the loop, since this is a convenient place to do it.
-- (Though it seems that this would be better done in Expand_Actuals???)
- Formal := First_Formal (Subp);
- Actual := First_Actual (N);
+ Formal := First_Formal (Subp);
+ Actual := First_Actual (Call_Node);
Param_Count := 1;
while Present (Formal) loop
CW_Interface_Formals_Present
or else
(Ekind (Etype (Formal)) = E_Class_Wide_Type
- and then Is_Interface (Etype (Etype (Formal))))
+ and then Is_Interface (Etype (Etype (Formal))))
or else
(Ekind (Etype (Formal)) = E_Anonymous_Access_Type
and then Is_Interface (Directly_Designated_Type
Prev_Orig := Prev;
end if;
- -- Ada 2005 (AI-251): Thunks must propagate the extra actuals
- -- of accessibility levels.
+ -- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
+ -- accessibility levels.
if Ekind (Current_Scope) in Subprogram_Kind
and then Is_Thunk (Current_Scope)
else
Add_Extra_Actual
- (Make_Integer_Literal (Loc,
- Intval => Type_Access_Level (Etype (Prev_Orig))),
+ (Dynamic_Accessibility_Level (Prev_Orig),
Extra_Accessibility (Formal));
end if;
-- For X'Access, pass on the level of the prefix X
when Attribute_Access =>
- Add_Extra_Actual
- (Make_Integer_Literal (Loc,
- Intval =>
- Object_Access_Level
- (Prefix (Prev_Orig))),
- Extra_Accessibility (Formal));
+
+ -- If this is an Access attribute applied to the
+ -- the current instance object passed to a type
+ -- initialization procedure, then use the level
+ -- of the type itself. This is not really correct,
+ -- as there should be an extra level parameter
+ -- passed in with _init formals (only in the case
+ -- where the type is immutably limited), but we
+ -- don't have an easy way currently to create such
+ -- an extra formal (init procs aren't ever frozen).
+ -- For now we just use the level of the type,
+ -- which may be too shallow, but that works better
+ -- than passing Object_Access_Level of the type,
+ -- which can be one level too deep in some cases.
+ -- ???
+
+ if Is_Entity_Name (Prefix (Prev_Orig))
+ and then Is_Type (Entity (Prefix (Prev_Orig)))
+ then
+ Add_Extra_Actual
+ (Make_Integer_Literal (Loc,
+ Intval =>
+ Type_Access_Level
+ (Entity (Prefix (Prev_Orig)))),
+ Extra_Accessibility (Formal));
+
+ else
+ Add_Extra_Actual
+ (Make_Integer_Literal (Loc,
+ Intval =>
+ Object_Access_Level
+ (Prefix (Prev_Orig))),
+ Extra_Accessibility (Formal));
+ end if;
-- Treat the unchecked attributes as library-level
Extra_Accessibility (Formal));
-- No other cases of attributes returning access
- -- values that can be passed to access parameters
+ -- values that can be passed to access parameters.
when others =>
raise Program_Error;
Intval => Scope_Depth (Current_Scope) + 1),
Extra_Accessibility (Formal));
- -- For other cases we simply pass the level of the actual's
- -- access type. The type is retrieved from Prev rather than
- -- Prev_Orig, because in some cases Prev_Orig denotes an
- -- original expression that has not been analyzed.
+ -- For most other cases we simply pass the level of the
+ -- actual's access type. The type is retrieved from
+ -- Prev rather than Prev_Orig, because in some cases
+ -- Prev_Orig denotes an original expression that has
+ -- not been analyzed.
when others =>
Add_Extra_Actual
- (Make_Integer_Literal (Loc,
- Intval => Type_Access_Level (Etype (Prev))),
+ (Dynamic_Accessibility_Level (Prev),
Extra_Accessibility (Formal));
end case;
end if;
end if;
-- Perform the check of 4.6(49) that prevents a null value from being
- -- passed as an actual to an access parameter. Note that the check is
- -- elided in the common cases of passing an access attribute or
+ -- passed as an actual to an access parameter. Note that the check
+ -- is elided in the common cases of passing an access attribute or
-- access parameter as an actual. Also, we currently don't enforce
-- this check for expander-generated actuals and when -gnatdj is set.
- if Ada_Version >= Ada_05 then
+ if Ada_Version >= Ada_2005 then
- -- Ada 2005 (AI-231): Check null-excluding access types
+ -- Ada 2005 (AI-231): Check null-excluding access types. Note that
+ -- the intent of 6.4.1(13) is that null-exclusion checks should
+ -- not be done for 'out' parameters, even though it refers only
+ -- to constraint checks, and a null_exclusion is not a constraint.
+ -- Note that AI05-0196-1 corrects this mistake in the RM.
if Is_Access_Type (Etype (Formal))
and then Can_Never_Be_Null (Etype (Formal))
+ and then Ekind (Formal) /= E_Out_Parameter
and then Nkind (Prev) /= N_Raise_Constraint_Error
and then (Known_Null (Prev)
- or else not Can_Never_Be_Null (Etype (Prev)))
+ or else not Can_Never_Be_Null (Etype (Prev)))
then
Install_Null_Excluding_Check (Prev);
end if;
- -- Ada_Version < Ada_05
+ -- Ada_Version < Ada_2005
else
if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
if Validity_Checks_On then
if (Ekind (Formal) = E_In_Parameter
- and then Validity_Check_In_Params)
+ and then Validity_Check_In_Params)
or else
(Ekind (Formal) = E_In_Out_Parameter
- and then Validity_Check_In_Out_Params)
+ and then Validity_Check_In_Out_Params)
then
-- If the actual is an indexed component of a packed type (or
-- is an indexed or selected component whose prefix recursively
end if;
end if;
+ -- For Ada 2012, if a parameter is aliased, the actual must be a
+ -- tagged type or an aliased view of an object.
+
+ if Is_Aliased (Formal)
+ and then not Is_Aliased_View (Actual)
+ and then not Is_Tagged_Type (Etype (Formal))
+ then
+ Error_Msg_NE
+ ("actual for aliased formal& must be aliased object",
+ Actual, Formal);
+ end if;
+
-- For IN OUT and OUT parameters, ensure that subscripts are valid
-- since this is a left side reference. We only do this for calls
-- from the source program since we assume that compiler generated
-- calls explicitly generate any required checks. We also need it
- -- only if we are doing standard validity checks, since clearly it
- -- is not needed if validity checks are off, and in subscript
- -- validity checking mode, all indexed components are checked with
- -- a call directly from Expand_N_Indexed_Component.
+ -- only if we are doing standard validity checks, since clearly it is
+ -- not needed if validity checks are off, and in subscript validity
+ -- checking mode, all indexed components are checked with a call
+ -- directly from Expand_N_Indexed_Component.
- if Comes_From_Source (N)
+ if Comes_From_Source (Call_Node)
and then Ekind (Formal) /= E_In_Parameter
and then Validity_Checks_On
and then Validity_Check_Default
-- or IN OUT parameter! We do reset the Is_Known_Valid flag
-- since the subprogram could have returned in invalid value.
- if (Ekind (Formal) = E_Out_Parameter
- or else
- Ekind (Formal) = E_In_Out_Parameter)
+ if Ekind_In (Formal, E_Out_Parameter, E_In_Out_Parameter)
and then Is_Assignable (Ent)
then
Sav := Last_Assignment (Ent);
Next_Formal (Formal);
end loop;
+ -- If we are calling an Ada 2012 function which needs to have the
+ -- "accessibility level determined by the point of call" (AI05-0234)
+ -- passed in to it, then pass it in.
+
+ if Ekind_In (Subp, E_Function, E_Operator, E_Subprogram_Type)
+ and then
+ Present (Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)))
+ then
+ declare
+ Ancestor : Node_Id := Parent (Call_Node);
+ Level : Node_Id := Empty;
+ Defer : Boolean := False;
+
+ begin
+ -- Unimplemented: if Subp returns an anonymous access type, then
+
+ -- a) if the call is the operand of an explict conversion, then
+ -- the target type of the conversion (a named access type)
+ -- determines the accessibility level pass in;
+
+ -- b) if the call defines an access discriminant of an object
+ -- (e.g., the discriminant of an object being created by an
+ -- allocator, or the discriminant of a function result),
+ -- then the accessibility level to pass in is that of the
+ -- discriminated object being initialized).
+
+ -- ???
+
+ while Nkind (Ancestor) = N_Qualified_Expression
+ loop
+ Ancestor := Parent (Ancestor);
+ end loop;
+
+ case Nkind (Ancestor) is
+ when N_Allocator =>
+
+ -- At this point, we'd like to assign
+
+ -- Level := Dynamic_Accessibility_Level (Ancestor);
+
+ -- but Etype of Ancestor may not have been set yet,
+ -- so that doesn't work.
+
+ -- Handle this later in Expand_Allocator_Expression.
+
+ Defer := True;
+
+ when N_Object_Declaration | N_Object_Renaming_Declaration =>
+ declare
+ Def_Id : constant Entity_Id :=
+ Defining_Identifier (Ancestor);
+
+ begin
+ if Is_Return_Object (Def_Id) then
+ if Present (Extra_Accessibility_Of_Result
+ (Return_Applies_To (Scope (Def_Id))))
+ then
+ -- Pass along value that was passed in if the
+ -- routine we are returning from also has an
+ -- Accessibility_Of_Result formal.
+
+ Level :=
+ New_Occurrence_Of
+ (Extra_Accessibility_Of_Result
+ (Return_Applies_To (Scope (Def_Id))), Loc);
+ end if;
+ else
+ Level :=
+ Make_Integer_Literal (Loc,
+ Intval => Object_Access_Level (Def_Id));
+ end if;
+ end;
+
+ when N_Simple_Return_Statement =>
+ if Present (Extra_Accessibility_Of_Result
+ (Return_Applies_To
+ (Return_Statement_Entity (Ancestor))))
+ then
+ -- Pass along value that was passed in if the routine
+ -- we are returning from also has an
+ -- Accessibility_Of_Result formal.
+
+ Level :=
+ New_Occurrence_Of
+ (Extra_Accessibility_Of_Result
+ (Return_Applies_To
+ (Return_Statement_Entity (Ancestor))), Loc);
+ end if;
+
+ when others =>
+ null;
+ end case;
+
+ if not Defer then
+ if not Present (Level) then
+
+ -- The "innermost master that evaluates the function call".
+
+ -- ??? - Should we use Integer'Last here instead in order
+ -- to deal with (some of) the problems associated with
+ -- calls to subps whose enclosing scope is unknown (e.g.,
+ -- Anon_Access_To_Subp_Param.all)?
+
+ Level := Make_Integer_Literal (Loc,
+ Scope_Depth (Current_Scope) + 1);
+ end if;
+
+ Add_Extra_Actual
+ (Level,
+ Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)));
+ end if;
+ end;
+ end if;
+
-- If we are expanding a rhs of an assignment we need to check if tag
-- propagation is needed. You might expect this processing to be in
-- Analyze_Assignment but has to be done earlier (bottom-up) because the
-- assignment might be transformed to a declaration for an unconstrained
-- value if the expression is classwide.
- if Nkind (N) = N_Function_Call
- and then Is_Tag_Indeterminate (N)
- and then Is_Entity_Name (Name (N))
+ if Nkind (Call_Node) = N_Function_Call
+ and then Is_Tag_Indeterminate (Call_Node)
+ and then Is_Entity_Name (Name (Call_Node))
then
declare
Ass : Node_Id := Empty;
begin
- if Nkind (Parent (N)) = N_Assignment_Statement then
- Ass := Parent (N);
+ if Nkind (Parent (Call_Node)) = N_Assignment_Statement then
+ Ass := Parent (Call_Node);
- elsif Nkind (Parent (N)) = N_Qualified_Expression
- and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
+ elsif Nkind (Parent (Call_Node)) = N_Qualified_Expression
+ and then Nkind (Parent (Parent (Call_Node))) =
+ N_Assignment_Statement
then
- Ass := Parent (Parent (N));
+ Ass := Parent (Parent (Call_Node));
- elsif Nkind (Parent (N)) = N_Explicit_Dereference
- and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
+ elsif Nkind (Parent (Call_Node)) = N_Explicit_Dereference
+ and then Nkind (Parent (Parent (Call_Node))) =
+ N_Assignment_Statement
then
- Ass := Parent (Parent (N));
+ Ass := Parent (Parent (Call_Node));
end if;
if Present (Ass)
and then Is_Class_Wide_Type (Etype (Name (Ass)))
then
- if Is_Access_Type (Etype (N)) then
- if Designated_Type (Etype (N)) /=
+ if Is_Access_Type (Etype (Call_Node)) then
+ if Designated_Type (Etype (Call_Node)) /=
Root_Type (Etype (Name (Ass)))
then
Error_Msg_NE
("tag-indeterminate expression "
& " must have designated type& (RM 5.2 (6))",
- N, Root_Type (Etype (Name (Ass))));
+ Call_Node, Root_Type (Etype (Name (Ass))));
else
- Propagate_Tag (Name (Ass), N);
+ Propagate_Tag (Name (Ass), Call_Node);
end if;
- elsif Etype (N) /= Root_Type (Etype (Name (Ass))) then
+ elsif Etype (Call_Node) /= Root_Type (Etype (Name (Ass))) then
Error_Msg_NE
("tag-indeterminate expression must have type&"
- & "(RM 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
+ & "(RM 5.2 (6))",
+ Call_Node, Root_Type (Etype (Name (Ass))));
else
- Propagate_Tag (Name (Ass), N);
+ Propagate_Tag (Name (Ass), Call_Node);
end if;
-- The call will be rewritten as a dispatching call, and
-- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
-- it to point to the correct secondary virtual table
- if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
+ if Nkind_In (Call_Node, N_Function_Call, N_Procedure_Call_Statement)
and then CW_Interface_Formals_Present
then
- Expand_Interface_Actuals (N);
+ Expand_Interface_Actuals (Call_Node);
end if;
-- Deals with Dispatch_Call if we still have a call, before expanding
-- extra actuals since this will be done on the re-analysis of the
- -- dispatching call. Note that we do not try to shorten the actual
- -- list for a dispatching call, it would not make sense to do so.
- -- Expansion of dispatching calls is suppressed when VM_Target, because
- -- the VM back-ends directly handle the generation of dispatching
- -- calls and would have to undo any expansion to an indirect call.
-
- if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
- and then Present (Controlling_Argument (N))
+ -- dispatching call. Note that we do not try to shorten the actual list
+ -- for a dispatching call, it would not make sense to do so. Expansion
+ -- of dispatching calls is suppressed when VM_Target, because the VM
+ -- back-ends directly handle the generation of dispatching calls and
+ -- would have to undo any expansion to an indirect call.
+
+ if Nkind_In (Call_Node, N_Function_Call, N_Procedure_Call_Statement)
+ and then Present (Controlling_Argument (Call_Node))
then
- if Tagged_Type_Expansion then
- Expand_Dispatching_Call (N);
+ declare
+ Call_Typ : constant Entity_Id := Etype (Call_Node);
+ Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
+ Eq_Prim_Op : Entity_Id := Empty;
+ New_Call : Node_Id;
+ Param : Node_Id;
+ Prev_Call : Node_Id;
- -- The following return is worrisome. Is it really OK to
- -- skip all remaining processing in this procedure ???
+ begin
+ if not Is_Limited_Type (Typ) then
+ Eq_Prim_Op := Find_Prim_Op (Typ, Name_Op_Eq);
+ end if;
- return;
+ if Tagged_Type_Expansion then
+ Expand_Dispatching_Call (Call_Node);
- else
- Apply_Tag_Checks (N);
+ -- The following return is worrisome. Is it really OK to skip
+ -- all remaining processing in this procedure ???
+
+ return;
- -- Expansion of a dispatching call results in an indirect call,
- -- which in turn causes current values to be killed (see
- -- Resolve_Call), so on VM targets we do the call here to ensure
- -- consistent warnings between VM and non-VM targets.
+ -- VM targets
- Kill_Current_Values;
- end if;
+ else
+ Apply_Tag_Checks (Call_Node);
+
+ -- If this is a dispatching "=", we must first compare the
+ -- tags so we generate: x.tag = y.tag and then x = y
+
+ if Subp = Eq_Prim_Op then
+
+ -- Mark the node as analyzed to avoid reanalizing this
+ -- dispatching call (which would cause a never-ending loop)
+
+ Prev_Call := Relocate_Node (Call_Node);
+ Set_Analyzed (Prev_Call);
+
+ Param := First_Actual (Call_Node);
+ New_Call :=
+ Make_And_Then (Loc,
+ Left_Opnd =>
+ Make_Op_Eq (Loc,
+ Left_Opnd =>
+ Make_Selected_Component (Loc,
+ Prefix => New_Value (Param),
+ Selector_Name =>
+ New_Reference_To (First_Tag_Component (Typ),
+ Loc)),
+
+ Right_Opnd =>
+ Make_Selected_Component (Loc,
+ Prefix =>
+ Unchecked_Convert_To (Typ,
+ New_Value (Next_Actual (Param))),
+ Selector_Name =>
+ New_Reference_To
+ (First_Tag_Component (Typ), Loc))),
+ Right_Opnd => Prev_Call);
+
+ Rewrite (Call_Node, New_Call);
+
+ Analyze_And_Resolve
+ (Call_Node, Call_Typ, Suppress => All_Checks);
+ end if;
+
+ -- Expansion of a dispatching call results in an indirect call,
+ -- which in turn causes current values to be killed (see
+ -- Resolve_Call), so on VM targets we do the call here to
+ -- ensure consistent warnings between VM and non-VM targets.
+
+ Kill_Current_Values;
+ end if;
+
+ -- If this is a dispatching "=" then we must update the reference
+ -- to the call node because we generated:
+ -- x.tag = y.tag and then x = y
+
+ if Subp = Eq_Prim_Op then
+ Call_Node := Right_Opnd (Call_Node);
+ end if;
+ end;
end if;
-- Similarly, expand calls to RCI subprograms on which pragma
-- All_Calls_Remote applies. The rewriting will be reanalyzed
- -- later. Do this only when the call comes from source since we do
- -- not want such a rewriting to occur in expanded code.
+ -- later. Do this only when the call comes from source since we
+ -- do not want such a rewriting to occur in expanded code.
- if Is_All_Remote_Call (N) then
- Expand_All_Calls_Remote_Subprogram_Call (N);
+ if Is_All_Remote_Call (Call_Node) then
+ Expand_All_Calls_Remote_Subprogram_Call (Call_Node);
-- Similarly, do not add extra actuals for an entry call whose entity
-- is a protected procedure, or for an internal protected subprogram
end loop;
end if;
- -- At this point we have all the actuals, so this is the point at
- -- which the various expansion activities for actuals is carried out.
+ -- At this point we have all the actuals, so this is the point at which
+ -- the various expansion activities for actuals is carried out.
- Expand_Actuals (N, Subp);
+ Expand_Actuals (Call_Node, Subp);
- -- If the subprogram is a renaming, or if it is inherited, replace it
- -- in the call with the name of the actual subprogram being called.
- -- If this is a dispatching call, the run-time decides what to call.
- -- The Alias attribute does not apply to entries.
+ -- If the subprogram is a renaming, or if it is inherited, replace it in
+ -- the call with the name of the actual subprogram being called. If this
+ -- is a dispatching call, the run-time decides what to call. The Alias
+ -- attribute does not apply to entries.
- if Nkind (N) /= N_Entry_Call_Statement
- and then No (Controlling_Argument (N))
+ if Nkind (Call_Node) /= N_Entry_Call_Statement
+ and then No (Controlling_Argument (Call_Node))
and then Present (Parent_Subp)
+ and then not Is_Direct_Deep_Call (Subp)
then
if Present (Inherited_From_Formal (Subp)) then
Parent_Subp := Inherited_From_Formal (Subp);
-- The below setting of Entity is suspect, see F109-018 discussion???
- Set_Entity (Name (N), Parent_Subp);
+ Set_Entity (Name (Call_Node), Parent_Subp);
if Is_Abstract_Subprogram (Parent_Subp)
and then not In_Instance
then
Error_Msg_NE
- ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
+ ("cannot call abstract subprogram &!",
+ Name (Call_Node), Parent_Subp);
end if;
-- Inspect all formals of derived subprogram Subp. Compare parameter
Parent_Typ : Entity_Id;
begin
- Actual := First_Actual (N);
+ Actual := First_Actual (Call_Node);
Formal := First_Formal (Subp);
Parent_Formal := First_Formal (Parent_Subp);
while Present (Formal) loop
-- Check for violation of No_Abort_Statements
- if Is_RTE (Subp, RE_Abort_Task) then
- Check_Restriction (No_Abort_Statements, N);
+ if Restriction_Check_Required (No_Abort_Statements)
+ and then Is_RTE (Subp, RE_Abort_Task)
+ then
+ Check_Restriction (No_Abort_Statements, Call_Node);
-- Check for violation of No_Dynamic_Attachment
- elsif RTU_Loaded (Ada_Interrupts)
+ elsif Restriction_Check_Required (No_Dynamic_Attachment)
+ and then RTU_Loaded (Ada_Interrupts)
and then (Is_RTE (Subp, RE_Is_Reserved) or else
Is_RTE (Subp, RE_Is_Attached) or else
Is_RTE (Subp, RE_Current_Handler) or else
Is_RTE (Subp, RE_Detach_Handler) or else
Is_RTE (Subp, RE_Reference))
then
- Check_Restriction (No_Dynamic_Attachment, N);
+ Check_Restriction (No_Dynamic_Attachment, Call_Node);
end if;
-- Deal with case where call is an explicit dereference
- if Nkind (Name (N)) = N_Explicit_Dereference then
+ if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
-- Handle case of access to protected subprogram type
if Is_Access_Protected_Subprogram_Type
- (Base_Type (Etype (Prefix (Name (N)))))
+ (Base_Type (Etype (Prefix (Name (Call_Node)))))
then
- -- If this is a call through an access to protected operation,
- -- the prefix has the form (object'address, operation'access).
- -- Rewrite as a for other protected calls: the object is the
- -- first parameter of the list of actuals.
+ -- If this is a call through an access to protected operation, the
+ -- prefix has the form (object'address, operation'access). Rewrite
+ -- as a for other protected calls: the object is the 1st parameter
+ -- of the list of actuals.
declare
Call : Node_Id;
Parm : List_Id;
Nam : Node_Id;
Obj : Node_Id;
- Ptr : constant Node_Id := Prefix (Name (N));
+ Ptr : constant Node_Id := Prefix (Name (Call_Node));
T : constant Entity_Id :=
Equivalent_Type (Base_Type (Etype (Ptr)));
Make_Explicit_Dereference (Loc,
Prefix => Nam);
- if Present (Parameter_Associations (N)) then
- Parm := Parameter_Associations (N);
+ if Present (Parameter_Associations (Call_Node)) then
+ Parm := Parameter_Associations (Call_Node);
else
Parm := New_List;
end if;
Parameter_Associations => Parm);
end if;
- Set_First_Named_Actual (Call, First_Named_Actual (N));
+ Set_First_Named_Actual (Call, First_Named_Actual (Call_Node));
Set_Etype (Call, Etype (D_T));
-- We do not re-analyze the call to avoid infinite recursion.
-- the checks on the prefix that would otherwise be emitted
-- when resolving a call.
- Rewrite (N, Call);
+ Rewrite (Call_Node, Call);
Analyze (Nam);
Apply_Access_Check (Nam);
Analyze (Obj);
-- In the case where the intrinsic is to be processed by the back end,
-- the call to Expand_Intrinsic_Call will do nothing, which is fine,
- -- since the idea in this case is to pass the call unchanged.
- -- If the intrinsic is an inherited unchecked conversion, and the
- -- derived type is the target type of the conversion, we must retain
- -- it as the return type of the expression. Otherwise the expansion
- -- below, which uses the parent operation, will yield the wrong type.
+ -- since the idea in this case is to pass the call unchanged. If the
+ -- intrinsic is an inherited unchecked conversion, and the derived type
+ -- is the target type of the conversion, we must retain it as the return
+ -- type of the expression. Otherwise the expansion below, which uses the
+ -- parent operation, will yield the wrong type.
if Is_Intrinsic_Subprogram (Subp) then
- Expand_Intrinsic_Call (N, Subp);
+ Expand_Intrinsic_Call (Call_Node, Subp);
- if Nkind (N) = N_Unchecked_Type_Conversion
+ if Nkind (Call_Node) = N_Unchecked_Type_Conversion
and then Parent_Subp /= Orig_Subp
and then Etype (Parent_Subp) /= Etype (Orig_Subp)
then
- Set_Etype (N, Etype (Orig_Subp));
+ Set_Etype (Call_Node, Etype (Orig_Subp));
end if;
return;
-- that tree generated is the same in both cases, for Inspector use.
if Is_RTE (Subp, RE_To_Address) then
- Rewrite (N,
+ Rewrite (Call_Node,
Unchecked_Convert_To
- (RTE (RE_Address), Relocate_Node (First_Actual (N))));
+ (RTE (RE_Address), Relocate_Node (First_Actual (Call_Node))));
return;
elsif Is_Null_Procedure (Subp) then
- Rewrite (N, Make_Null_Statement (Loc));
+ Rewrite (Call_Node, Make_Null_Statement (Loc));
return;
end if;
else
Bod := Body_To_Inline (Spec);
- if (In_Extended_Main_Code_Unit (N)
- or else In_Extended_Main_Code_Unit (Parent (N))
+ if (In_Extended_Main_Code_Unit (Call_Node)
+ or else In_Extended_Main_Code_Unit (Parent (Call_Node))
or else Has_Pragma_Inline_Always (Subp))
and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
or else
-- visible a private entity in the body of the main unit,
-- that gigi will see before its sees its proper definition.
- elsif not (In_Extended_Main_Code_Unit (N))
+ elsif not (In_Extended_Main_Code_Unit (Call_Node))
and then In_Package_Body
then
Must_Inline := not In_Extended_Main_Source_Unit (Subp);
end if;
if Must_Inline then
- Expand_Inlined_Call (N, Subp, Orig_Subp);
+ Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
else
-- Let the back end handle it
if Front_End_Inlining
and then Nkind (Spec) = N_Subprogram_Declaration
- and then (In_Extended_Main_Code_Unit (N))
+ and then (In_Extended_Main_Code_Unit (Call_Node))
and then No (Body_To_Inline (Spec))
and then not Has_Completion (Subp)
and then In_Same_Extended_Unit (Sloc (Spec), Loc)
then
Cannot_Inline
- ("cannot inline& (body not seen yet)?", N, Subp);
+ ("cannot inline& (body not seen yet)?", Call_Node, Subp);
end if;
end if;
end Inlined_Subprogram;
Scop := Scope (Subp);
- if Nkind (N) /= N_Entry_Call_Statement
+ if Nkind (Call_Node) /= N_Entry_Call_Statement
and then Is_Protected_Type (Scop)
and then Ekind (Subp) /= E_Subprogram_Type
and then not Is_Eliminated (Subp)
-- If the call is an internal one, it is rewritten as a call to the
-- corresponding unprotected subprogram.
- Expand_Protected_Subprogram_Call (N, Subp, Scop);
+ Expand_Protected_Subprogram_Call (Call_Node, Subp, Scop);
end if;
- -- Functions returning controlled objects need special attention:
- -- if the return type is limited, the context is an initialization
- -- and different processing applies. If the call is to a protected
- -- function, the expansion above will call Expand_Call recusively.
- -- To prevent a double attachment, check that the current call is
- -- not a rewriting of a protected function call.
+ -- Functions returning controlled objects need special attention. If
+ -- the return type is limited, then the context is initialization and
+ -- different processing applies. If the call is to a protected function,
+ -- the expansion above will call Expand_Call recursively. Otherwise the
+ -- function call is transformed into a temporary which obtains the
+ -- result from the secondary stack.
- if Needs_Finalization (Etype (Subp))
- and then not Is_Inherently_Limited_Type (Etype (Subp))
- and then
- (No (First_Formal (Subp))
- or else
- not Is_Concurrent_Record_Type (Etype (First_Formal (Subp))))
- then
- Expand_Ctrl_Function_Call (N);
+ if Needs_Finalization (Etype (Subp)) then
+ if not Is_Immutably_Limited_Type (Etype (Subp))
+ and then
+ (No (First_Formal (Subp))
+ or else
+ not Is_Concurrent_Record_Type (Etype (First_Formal (Subp))))
+ then
+ Expand_Ctrl_Function_Call (Call_Node);
+
+ -- Build-in-place function calls which appear in anonymous contexts
+ -- need a transient scope to ensure the proper finalization of the
+ -- intermediate result after its use.
+
+ elsif Is_Build_In_Place_Function_Call (Call_Node)
+ and then Nkind_In (Parent (Call_Node), N_Attribute_Reference,
+ N_Function_Call,
+ N_Indexed_Component,
+ N_Object_Renaming_Declaration,
+ N_Procedure_Call_Statement,
+ N_Selected_Component,
+ N_Slice)
+ then
+ Establish_Transient_Scope (Call_Node, Sec_Stack => True);
+ end if;
end if;
-- Test for First_Optional_Parameter, and if so, truncate parameter list
-- the validity of the parameter before setting it.
Formal := First_Formal (Subp);
- Actual := First_Actual (N);
+ Actual := First_Actual (Call_Node);
while Formal /= First_Optional_Parameter (Subp) loop
Last_Keep_Arg := Actual;
Next_Formal (Formal);
-- If no arguments, delete entire list, this is the easy case
if No (Last_Keep_Arg) then
- Set_Parameter_Associations (N, No_List);
- Set_First_Named_Actual (N, Empty);
+ Set_Parameter_Associations (Call_Node, No_List);
+ Set_First_Named_Actual (Call_Node, Empty);
-- Case where at the last retained argument is positional. This
-- is also an easy case, since the retained arguments are already
Discard_Node (Remove_Next (Last_Keep_Arg));
end loop;
- Set_First_Named_Actual (N, Empty);
+ Set_First_Named_Actual (Call_Node, Empty);
-- This is the annoying case where the last retained argument
-- is a named parameter. Since the original arguments are not
-- list (they are still chained using First_Named_Actual
-- and Next_Named_Actual, so we have not lost them!)
- Temp := First (Parameter_Associations (N));
+ Temp := First (Parameter_Associations (Call_Node));
-- Case of all parameters named, remove them all
if Nkind (Temp) = N_Parameter_Association then
- while Is_Non_Empty_List (Parameter_Associations (N)) loop
- Temp := Remove_Head (Parameter_Associations (N));
+ -- Suppress warnings to avoid warning on possible
+ -- infinite loop (because Call_Node is not modified).
+
+ pragma Warnings (Off);
+ while Is_Non_Empty_List
+ (Parameter_Associations (Call_Node))
+ loop
+ Temp :=
+ Remove_Head (Parameter_Associations (Call_Node));
end loop;
+ pragma Warnings (On);
-- Case of mixed positional/named, remove named parameters
-- touched since we are only reordering them on the actual
-- parameter association list.
- Passoc := Parent (First_Named_Actual (N));
+ Passoc := Parent (First_Named_Actual (Call_Node));
loop
Temp := Relocate_Node (Passoc);
Append_To
- (Parameter_Associations (N), Temp);
+ (Parameter_Associations (Call_Node), Temp);
exit when
Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
Passoc := Parent (Next_Named_Actual (Passoc));
end if;
end Expand_Call;
+ -------------------------------
+ -- Expand_Ctrl_Function_Call --
+ -------------------------------
+
+ procedure Expand_Ctrl_Function_Call (N : Node_Id) is
+ begin
+ -- Optimization, if the returned value (which is on the sec-stack) is
+ -- returned again, no need to copy/readjust/finalize, we can just pass
+ -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
+ -- attachment is needed
+
+ if Nkind (Parent (N)) = N_Simple_Return_Statement then
+ return;
+ end if;
+
+ -- Resolution is now finished, make sure we don't start analysis again
+ -- because of the duplication.
+
+ Set_Analyzed (N);
+
+ -- A function which returns a controlled object uses the secondary
+ -- stack. Rewrite the call into a temporary which obtains the result of
+ -- the function using 'reference.
+
+ Remove_Side_Effects (N);
+ end Expand_Ctrl_Function_Call;
+
--------------------------
-- Expand_Inlined_Call --
--------------------------
New_A : Node_Id;
Num_Ret : Int := 0;
Ret_Type : Entity_Id;
- Targ : Node_Id;
- Targ1 : Node_Id;
+
+ Targ : Node_Id;
+ -- The target of the call. If context is an assignment statement then
+ -- this is the left-hand side of the assignment. else it is a temporary
+ -- to which the return value is assigned prior to rewriting the call.
+
+ Targ1 : Node_Id;
+ -- A separate target used when the return type is unconstrained
+
Temp : Entity_Id;
Temp_Typ : Entity_Id;
-- Entity in declaration in an extended_return_statement
Is_Unc : constant Boolean :=
- Is_Array_Type (Etype (Subp))
- and then not Is_Constrained (Etype (Subp));
+ Is_Array_Type (Etype (Subp))
+ and then not Is_Constrained (Etype (Subp));
-- If the type returned by the function is unconstrained and the call
-- can be inlined, special processing is required.
Rewrite (N, New_Copy (A));
end if;
end if;
+
return Skip;
elsif Is_Entity_Name (N)
if Nkind_In (Expression (N), N_Aggregate, N_Null) then
Ret :=
Make_Qualified_Expression (Sloc (N),
- Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
- Expression => Relocate_Node (Expression (N)));
+ Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
+ Expression => Relocate_Node (Expression (N)));
else
Ret :=
Unchecked_Convert_To
if Nkind (Targ) = N_Defining_Identifier then
Rewrite (N,
Make_Assignment_Statement (Loc,
- Name => New_Occurrence_Of (Targ, Loc),
+ Name => New_Occurrence_Of (Targ, Loc),
Expression => Ret));
else
Rewrite (N,
Make_Assignment_Statement (Loc,
- Name => New_Copy (Targ),
+ Name => New_Copy (Targ),
Expression => Ret));
end if;
if Present (Exit_Lab) then
Insert_After (N,
- Make_Goto_Statement (Loc,
- Name => New_Copy (Lab_Id)));
+ Make_Goto_Statement (Loc, Name => New_Copy (Lab_Id)));
end if;
end if;
return OK;
- elsif Nkind (N) = N_Extended_Return_Statement then
-
- -- An extended return becomes a block whose first statement is
- -- the assignment of the initial expression of the return object
- -- to the target of the call itself.
+ -- An extended return becomes a block whose first statement is the
+ -- assignment of the initial expression of the return object to the
+ -- target of the call itself.
+ elsif Nkind (N) = N_Extended_Return_Statement then
declare
Return_Decl : constant Entity_Id :=
First (Return_Object_Declarations (N));
if Nkind (Targ) = N_Defining_Identifier then
Assign :=
Make_Assignment_Statement (Loc,
- Name => New_Occurrence_Of (Targ, Loc),
+ Name => New_Occurrence_Of (Targ, Loc),
Expression => Expression (Return_Decl));
else
Assign :=
Make_Assignment_Statement (Loc,
- Name => New_Copy (Targ),
+ Name => New_Copy (Targ),
Expression => Expression (Return_Decl));
end if;
and then Nkind (Fst) = N_Assignment_Statement
and then No (Next (Fst))
then
-
-- The function call may have been rewritten as the temporary
-- that holds the result of the call, in which case remove the
-- now useless declaration.
Insert_After (Parent (Entity (N)), Blk);
+ -- If the context is an assignment, and the left-hand side is free of
+ -- side-effects, the replacement is also safe.
+ -- Can this be generalized further???
+
elsif Nkind (Parent (N)) = N_Assignment_Statement
and then
(Is_Entity_Name (Name (Parent (N)))
- or else
- (Nkind (Name (Parent (N))) = N_Explicit_Dereference
- and then Is_Entity_Name (Prefix (Name (Parent (N))))))
+ or else
+ (Nkind (Name (Parent (N))) = N_Explicit_Dereference
+ and then Is_Entity_Name (Prefix (Name (Parent (N)))))
+
+ or else
+ (Nkind (Name (Parent (N))) = N_Selected_Component
+ and then Is_Entity_Name (Prefix (Name (Parent (N))))))
then
-- Replace assignment with the block
procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
+
begin
-- If there is a transient scope for N, this will be the scope of the
-- actions for N, and the statements in Blk need to be within this
-- Start of processing for Expand_Inlined_Call
begin
-
-- Check for an illegal attempt to inline a recursive procedure. If the
-- subprogram has parameters this is detected when trying to supply a
-- binding for parameters that already have one. For parameterless
Set_Declarations (Blk, New_List);
end if;
- -- For the unconstrained case, capture the name of the local
- -- variable that holds the result. This must be the first declaration
- -- in the block, because its bounds cannot depend on local variables.
- -- Otherwise there is no way to declare the result outside of the
- -- block. Needless to say, in general the bounds will depend on the
- -- actuals in the call.
+ -- For the unconstrained case, capture the name of the local variable
+ -- that holds the result. This must be the first declaration in the
+ -- block, because its bounds cannot depend on local variables. Otherwise
+ -- there is no way to declare the result outside of the block. Needless
+ -- to say, in general the bounds will depend on the actuals in the call.
+
+ -- If the context is an assignment statement, as is the case for the
+ -- expansion of an extended return, the left-hand side provides bounds
+ -- even if the return type is unconstrained.
if Is_Unc then
- Targ1 := Defining_Identifier (First (Declarations (Blk)));
+ if Nkind (Parent (N)) /= N_Assignment_Statement then
+ Targ1 := Defining_Identifier (First (Declarations (Blk)));
+ else
+ Targ1 := Name (Parent (N));
+ end if;
end if;
-- If this is a derived function, establish the proper return type
- if Present (Orig_Subp)
- and then Orig_Subp /= Subp
- then
+ if Present (Orig_Subp) and then Orig_Subp /= Subp then
Ret_Type := Etype (Orig_Subp);
else
Ret_Type := Etype (Subp);
if Is_Class_Wide_Type (Etype (F))
or else (Is_Access_Type (Etype (F))
- and then
- Is_Class_Wide_Type (Designated_Type (Etype (F))))
+ and then Is_Class_Wide_Type (Designated_Type (Etype (F))))
then
Temp_Typ := Etype (F);
and then Etype (F) /= Base_Type (Etype (F))
then
Temp_Typ := Etype (F);
-
else
Temp_Typ := Etype (A);
end if;
or else
(Nkind_In (A, N_Real_Literal,
- N_Integer_Literal,
- N_Character_Literal)
- and then not Address_Taken (F))
+ N_Integer_Literal,
+ N_Character_Literal)
+ and then not Address_Taken (F))
then
if Etype (F) /= Etype (A) then
Set_Renamed_Object
- (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
+ (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
else
Set_Renamed_Object (F, A);
end if;
-- code will have the same semantics.
if Ekind (F) = E_In_Parameter
- and then not Is_Limited_Type (Etype (A))
- and then not Is_Tagged_Type (Etype (A))
+ and then not Is_By_Reference_Type (Etype (A))
and then
- (not Is_Array_Type (Etype (A))
- or else not Is_Object_Reference (A)
- or else Is_Bit_Packed_Array (Etype (A)))
+ (not Is_Array_Type (Etype (A))
+ or else not Is_Object_Reference (A)
+ or else Is_Bit_Packed_Array (Etype (A)))
then
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
- Constant_Present => True,
- Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
- Expression => New_A);
+ Constant_Present => True,
+ Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
+ Expression => New_A);
else
Decl :=
Make_Object_Renaming_Declaration (Loc,
end loop;
-- Establish target of function call. If context is not assignment or
- -- declaration, create a temporary as a target. The declaration for
- -- the temporary may be subsequently optimized away if the body is a
- -- single expression, or if the left-hand side of the assignment is
- -- simple enough, i.e. an entity or an explicit dereference of one.
+ -- declaration, create a temporary as a target. The declaration for the
+ -- temporary may be subsequently optimized away if the body is a single
+ -- expression, or if the left-hand side of the assignment is simple
+ -- enough, i.e. an entity or an explicit dereference of one.
if Ekind (Subp) = E_Function then
if Nkind (Parent (N)) = N_Assignment_Statement
then
Targ := Name (Parent (N));
+ elsif Nkind (Parent (N)) = N_Assignment_Statement
+ and then Nkind (Name (Parent (N))) = N_Selected_Component
+ and then Is_Entity_Name (Prefix (Name (Parent (N))))
+ then
+ Targ := New_Copy_Tree (Name (Parent (N)));
+
elsif Nkind (Parent (N)) = N_Object_Declaration
and then Is_Limited_Type (Etype (Subp))
then
-- eventually be possible to remove that temporary and use the
-- result variable directly.
- if Is_Unc then
+ if Is_Unc
+ and then Nkind (Parent (N)) /= N_Assignment_Statement
+ then
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
- Object_Definition =>
+ Object_Definition =>
New_Copy_Tree (Object_Definition (Parent (Targ1))));
Replace_Formals (Decl);
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
- Object_Definition =>
- New_Occurrence_Of (Ret_Type, Loc));
+ Object_Definition => New_Occurrence_Of (Ret_Type, Loc));
Set_Etype (Temp, Ret_Type);
end if;
Replace_Formals (Blk);
Set_Parent (Blk, N);
- if not Comes_From_Source (Subp)
- or else Is_Predef
- then
+ if not Comes_From_Source (Subp) or else Is_Predef then
Reset_Slocs (Blk);
end if;
if Num_Ret = 1
and then
Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
- N_Goto_Statement
+ N_Goto_Statement
then
Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
else
if Ekind (Subp) = E_Procedure then
Rewrite_Procedure_Call (N, Blk);
+
else
Rewrite_Function_Call (N, Blk);
end loop;
end Expand_Inlined_Call;
- ----------------------------
- -- Expand_N_Function_Call --
- ----------------------------
-
- procedure Expand_N_Function_Call (N : Node_Id) is
- begin
- Expand_Call (N);
+ ----------------------------------------
+ -- Expand_N_Extended_Return_Statement --
+ ----------------------------------------
- -- If the return value of a foreign compiled function is VAX Float, then
- -- expand the return (adjusts the location of the return value on
- -- Alpha/VMS, no-op everywhere else).
- -- Comes_From_Source intercepts recursive expansion.
+ -- If there is a Handled_Statement_Sequence, we rewrite this:
- if Vax_Float (Etype (N))
- and then Nkind (N) = N_Function_Call
- and then Present (Name (N))
- and then Present (Entity (Name (N)))
- and then Has_Foreign_Convention (Entity (Name (N)))
- and then Comes_From_Source (Parent (N))
- then
- Expand_Vax_Foreign_Return (N);
- end if;
- end Expand_N_Function_Call;
+ -- return Result : T := <expression> do
+ -- <handled_seq_of_stms>
+ -- end return;
- ---------------------------------------
- -- Expand_N_Procedure_Call_Statement --
- ---------------------------------------
+ -- to be:
- procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
- begin
- Expand_Call (N);
- end Expand_N_Procedure_Call_Statement;
+ -- declare
+ -- Result : T := <expression>;
+ -- begin
+ -- <handled_seq_of_stms>
+ -- return Result;
+ -- end;
- ------------------------------
- -- Expand_N_Subprogram_Body --
- ------------------------------
+ -- Otherwise (no Handled_Statement_Sequence), we rewrite this:
- -- Add poll call if ATC polling is enabled, unless the body will be inlined
- -- by the back-end.
+ -- return Result : T := <expression>;
- -- Add dummy push/pop label nodes at start and end to clear any local
- -- exception indications if local-exception-to-goto optimization is active.
+ -- to be:
- -- Add return statement if last statement in body is not a return statement
- -- (this makes things easier on Gigi which does not want to have to handle
- -- a missing return).
+ -- return <expression>;
- -- Add call to Activate_Tasks if body is a task activator
+ -- unless it's build-in-place or there's no <expression>, in which case
+ -- we generate:
- -- Deal with possible detection of infinite recursion
+ -- declare
+ -- Result : T := <expression>;
+ -- begin
+ -- return Result;
+ -- end;
- -- Eliminate body completely if convention stubbed
+ -- Note that this case could have been written by the user as an extended
+ -- return statement, or could have been transformed to this from a simple
+ -- return statement.
- -- Encode entity names within body, since we will not need to reference
- -- these entities any longer in the front end.
+ -- That is, we need to have a reified return object if there are statements
+ -- (which might refer to it) or if we're doing build-in-place (so we can
+ -- set its address to the final resting place or if there is no expression
+ -- (in which case default initial values might need to be set).
- -- Initialize scalar out parameters if Initialize/Normalize_Scalars
+ procedure Expand_N_Extended_Return_Statement (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
- -- Reset Pure indication if any parameter has root type System.Address
+ Par_Func : constant Entity_Id :=
+ Return_Applies_To (Return_Statement_Entity (N));
+ Result_Subt : constant Entity_Id := Etype (Par_Func);
+ Ret_Obj_Id : constant Entity_Id :=
+ First_Entity (Return_Statement_Entity (N));
+ Ret_Obj_Decl : constant Node_Id := Parent (Ret_Obj_Id);
+
+ Is_Build_In_Place : constant Boolean :=
+ Is_Build_In_Place_Function (Par_Func);
+
+ Exp : Node_Id;
+ HSS : Node_Id;
+ Result : Node_Id;
+ Return_Stmt : Node_Id;
+ Stmts : List_Id;
+
+ function Build_Heap_Allocator
+ (Temp_Id : Entity_Id;
+ Temp_Typ : Entity_Id;
+ Func_Id : Entity_Id;
+ Ret_Typ : Entity_Id;
+ Alloc_Expr : Node_Id) return Node_Id;
+ -- Create the statements necessary to allocate a return object on the
+ -- caller's master. The master is available through implicit parameter
+ -- BIPfinalizationmaster.
+ --
+ -- if BIPfinalizationmaster /= null then
+ -- declare
+ -- type Ptr_Typ is access Ret_Typ;
+ -- for Ptr_Typ'Storage_Pool use
+ -- Base_Pool (BIPfinalizationmaster.all).all;
+ -- Local : Ptr_Typ;
+ --
+ -- begin
+ -- procedure Allocate (...) is
+ -- begin
+ -- System.Storage_Pools.Subpools.Allocate_Any (...);
+ -- end Allocate;
+ --
+ -- Local := <Alloc_Expr>;
+ -- Temp_Id := Temp_Typ (Local);
+ -- end;
+ -- end if;
+ --
+ -- Temp_Id is the temporary which is used to reference the internally
+ -- created object in all allocation forms. Temp_Typ is the type of the
+ -- temporary. Func_Id is the enclosing function. Ret_Typ is the return
+ -- type of Func_Id. Alloc_Expr is the actual allocator.
+
+ function Move_Activation_Chain return Node_Id;
+ -- Construct a call to System.Tasking.Stages.Move_Activation_Chain
+ -- with parameters:
+ -- From current activation chain
+ -- To activation chain passed in by the caller
+ -- New_Master master passed in by the caller
- -- Wrap thread body
+ --------------------------
+ -- Build_Heap_Allocator --
+ --------------------------
- procedure Expand_N_Subprogram_Body (N : Node_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- H : constant Node_Id := Handled_Statement_Sequence (N);
- Body_Id : Entity_Id;
- Except_H : Node_Id;
- L : List_Id;
- Spec_Id : Entity_Id;
+ function Build_Heap_Allocator
+ (Temp_Id : Entity_Id;
+ Temp_Typ : Entity_Id;
+ Func_Id : Entity_Id;
+ Ret_Typ : Entity_Id;
+ Alloc_Expr : Node_Id) return Node_Id
+ is
+ begin
+ pragma Assert (Is_Build_In_Place_Function (Func_Id));
- procedure Add_Return (S : List_Id);
- -- Append a return statement to the statement sequence S if the last
- -- statement is not already a return or a goto statement. Note that
- -- the latter test is not critical, it does not matter if we add a few
- -- extra returns, since they get eliminated anyway later on.
+ -- Processing for build-in-place object allocation. This is disabled
+ -- on .NET/JVM because the targets do not support pools.
- ----------------
- -- Add_Return --
- ----------------
+ if VM_Target = No_VM
+ and then Needs_Finalization (Ret_Typ)
+ then
+ declare
+ Decls : constant List_Id := New_List;
+ Fin_Mas_Id : constant Entity_Id :=
+ Build_In_Place_Formal
+ (Func_Id, BIP_Finalization_Master);
+ Stmts : constant List_Id := New_List;
+ Desig_Typ : Entity_Id;
+ Local_Id : Entity_Id;
+ Pool_Id : Entity_Id;
+ Ptr_Typ : Entity_Id;
- procedure Add_Return (S : List_Id) is
- Last_Stm : Node_Id;
- Loc : Source_Ptr;
+ begin
+ -- Generate:
+ -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
- begin
- -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
- -- not relevant in this context since they are not executable.
+ Pool_Id := Make_Temporary (Loc, 'P');
- Last_Stm := Last (S);
- while Nkind (Last_Stm) in N_Pop_xxx_Label loop
- Prev (Last_Stm);
- end loop;
+ Append_To (Decls,
+ Make_Object_Renaming_Declaration (Loc,
+ Defining_Identifier => Pool_Id,
+ Subtype_Mark =>
+ New_Reference_To (RTE (RE_Root_Storage_Pool), Loc),
+ Name =>
+ Make_Explicit_Dereference (Loc,
+ Prefix =>
+ Make_Function_Call (Loc,
+ Name =>
+ New_Reference_To (RTE (RE_Base_Pool), Loc),
+ Parameter_Associations => New_List (
+ Make_Explicit_Dereference (Loc,
+ Prefix =>
+ New_Reference_To (Fin_Mas_Id, Loc)))))));
+
+ -- Create an access type which uses the storage pool of the
+ -- caller's master. This additional type is necessary because
+ -- the finalization master cannot be associated with the type
+ -- of the temporary. Otherwise the secondary stack allocation
+ -- will fail.
+
+ Desig_Typ := Ret_Typ;
+
+ -- Ensure that the build-in-place machinery uses a fat pointer
+ -- when allocating an unconstrained array on the heap. In this
+ -- case the result object type is a constrained array type even
+ -- though the function type is unconstrained.
+
+ if Ekind (Desig_Typ) = E_Array_Subtype then
+ Desig_Typ := Base_Type (Desig_Typ);
+ end if;
- -- Now insert return unless last statement is a transfer
+ -- Generate:
+ -- type Ptr_Typ is access Desig_Typ;
- if not Is_Transfer (Last_Stm) then
+ Ptr_Typ := Make_Temporary (Loc, 'P');
- -- The source location for the return is the end label of the
- -- procedure if present. Otherwise use the sloc of the last
- -- statement in the list. If the list comes from a generated
- -- exception handler and we are not debugging generated code,
- -- all the statements within the handler are made invisible
- -- to the debugger.
+ Append_To (Decls,
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Ptr_Typ,
+ Type_Definition =>
+ Make_Access_To_Object_Definition (Loc,
+ Subtype_Indication =>
+ New_Reference_To (Desig_Typ, Loc))));
- if Nkind (Parent (S)) = N_Exception_Handler
- and then not Comes_From_Source (Parent (S))
- then
- Loc := Sloc (Last_Stm);
+ -- Perform minor decoration in order to set the master and the
+ -- storage pool attributes.
- elsif Present (End_Label (H)) then
- Loc := Sloc (End_Label (H));
+ Set_Ekind (Ptr_Typ, E_Access_Type);
+ Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
+ Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
- else
- Loc := Sloc (Last_Stm);
- end if;
+ -- Create the temporary, generate:
+ -- Local_Id : Ptr_Typ;
- declare
- Rtn : constant Node_Id := Make_Simple_Return_Statement (Loc);
+ Local_Id := Make_Temporary (Loc, 'T');
- begin
- -- Append return statement, and set analyzed manually. We can't
- -- call Analyze on this return since the scope is wrong.
+ Append_To (Decls,
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Local_Id,
+ Object_Definition =>
+ New_Reference_To (Ptr_Typ, Loc)));
- -- Note: it almost works to push the scope and then do the
- -- Analyze call, but something goes wrong in some weird cases
- -- and it is not worth worrying about ???
+ -- Allocate the object, generate:
+ -- Local_Id := <Alloc_Expr>;
- Append_To (S, Rtn);
- Set_Analyzed (Rtn);
+ Append_To (Stmts,
+ Make_Assignment_Statement (Loc,
+ Name => New_Reference_To (Local_Id, Loc),
+ Expression => Alloc_Expr));
- -- Call _Postconditions procedure if appropriate. We need to
- -- do this explicitly because we did not analyze the generated
- -- return statement above, so the call did not get inserted.
+ -- Generate:
+ -- Temp_Id := Temp_Typ (Local_Id);
- if Ekind (Spec_Id) = E_Procedure
- and then Has_Postconditions (Spec_Id)
- then
- pragma Assert (Present (Postcondition_Proc (Spec_Id)));
- Insert_Action (Rtn,
- Make_Procedure_Call_Statement (Loc,
- Name =>
- New_Reference_To (Postcondition_Proc (Spec_Id), Loc)));
- end if;
+ Append_To (Stmts,
+ Make_Assignment_Statement (Loc,
+ Name => New_Reference_To (Temp_Id, Loc),
+ Expression =>
+ Unchecked_Convert_To (Temp_Typ,
+ New_Reference_To (Local_Id, Loc))));
+
+ -- Wrap the allocation in a block. This is further conditioned
+ -- by checking the caller finalization master at runtime. A
+ -- null value indicates a non-existent master, most likely due
+ -- to a Finalize_Storage_Only allocation.
+
+ -- Generate:
+ -- if BIPfinalizationmaster /= null then
+ -- declare
+ -- <Decls>
+ -- begin
+ -- <Stmts>
+ -- end;
+ -- end if;
+
+ return
+ Make_If_Statement (Loc,
+ Condition =>
+ Make_Op_Ne (Loc,
+ Left_Opnd => New_Reference_To (Fin_Mas_Id, Loc),
+ Right_Opnd => Make_Null (Loc)),
+
+ Then_Statements => New_List (
+ Make_Block_Statement (Loc,
+ Declarations => Decls,
+ Handled_Statement_Sequence =>
+ Make_Handled_Sequence_Of_Statements (Loc,
+ Statements => Stmts))));
end;
+
+ -- For all other cases, generate:
+ -- Temp_Id := <Alloc_Expr>;
+
+ else
+ return
+ Make_Assignment_Statement (Loc,
+ Name => New_Reference_To (Temp_Id, Loc),
+ Expression => Alloc_Expr);
end if;
- end Add_Return;
+ end Build_Heap_Allocator;
- -- Start of processing for Expand_N_Subprogram_Body
+ ---------------------------
+ -- Move_Activation_Chain --
+ ---------------------------
- begin
- -- Set L to either the list of declarations if present, or to the list
- -- of statements if no declarations are present. This is used to insert
- -- new stuff at the start.
+ function Move_Activation_Chain return Node_Id is
+ begin
+ return
+ Make_Procedure_Call_Statement (Loc,
+ Name =>
+ New_Reference_To (RTE (RE_Move_Activation_Chain), Loc),
- if Is_Non_Empty_List (Declarations (N)) then
- L := Declarations (N);
+ Parameter_Associations => New_List (
+
+ -- Source chain
+
+ Make_Attribute_Reference (Loc,
+ Prefix => Make_Identifier (Loc, Name_uChain),
+ Attribute_Name => Name_Unrestricted_Access),
+
+ -- Destination chain
+
+ New_Reference_To
+ (Build_In_Place_Formal (Par_Func, BIP_Activation_Chain), Loc),
+
+ -- New master
+
+ New_Reference_To
+ (Build_In_Place_Formal (Par_Func, BIP_Task_Master), Loc)));
+ end Move_Activation_Chain;
+
+ -- Start of processing for Expand_N_Extended_Return_Statement
+
+ begin
+ if Nkind (Ret_Obj_Decl) = N_Object_Declaration then
+ Exp := Expression (Ret_Obj_Decl);
else
- L := Statements (H);
+ Exp := Empty;
end if;
- -- If local-exception-to-goto optimization active, insert dummy push
- -- statements at start, and dummy pop statements at end.
+ HSS := Handled_Statement_Sequence (N);
- if (Debug_Flag_Dot_G
- or else Restriction_Active (No_Exception_Propagation))
- and then Is_Non_Empty_List (L)
+ -- If the returned object needs finalization actions, the function must
+ -- perform the appropriate cleanup should it fail to return. The state
+ -- of the function itself is tracked through a flag which is coupled
+ -- with the scope finalizer. There is one flag per each return object
+ -- in case of multiple returns.
+
+ if Is_Build_In_Place
+ and then Needs_Finalization (Etype (Ret_Obj_Id))
then
declare
- FS : constant Node_Id := First (L);
- FL : constant Source_Ptr := Sloc (FS);
- LS : Node_Id;
- LL : Source_Ptr;
+ Flag_Decl : Node_Id;
+ Flag_Id : Entity_Id;
+ Func_Bod : Node_Id;
begin
- -- LS points to either last statement, if statements are present
- -- or to the last declaration if there are no statements present.
- -- It is the node after which the pop's are generated.
+ -- Recover the function body
- if Is_Non_Empty_List (Statements (H)) then
- LS := Last (Statements (H));
- else
- LS := Last (L);
+ Func_Bod := Unit_Declaration_Node (Par_Func);
+
+ if Nkind (Func_Bod) = N_Subprogram_Declaration then
+ Func_Bod := Parent (Parent (Corresponding_Body (Func_Bod)));
end if;
- LL := Sloc (LS);
+ -- Create a flag to track the function state
- Insert_List_Before_And_Analyze (FS, New_List (
- Make_Push_Constraint_Error_Label (FL),
- Make_Push_Program_Error_Label (FL),
- Make_Push_Storage_Error_Label (FL)));
+ Flag_Id := Make_Temporary (Loc, 'F');
+ Set_Return_Flag_Or_Transient_Decl (Ret_Obj_Id, Flag_Id);
- Insert_List_After_And_Analyze (LS, New_List (
- Make_Pop_Constraint_Error_Label (LL),
- Make_Pop_Program_Error_Label (LL),
- Make_Pop_Storage_Error_Label (LL)));
+ -- Insert the flag at the beginning of the function declarations,
+ -- generate:
+ -- Fnn : Boolean := False;
+
+ Flag_Decl :=
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Flag_Id,
+ Object_Definition =>
+ New_Reference_To (Standard_Boolean, Loc),
+ Expression => New_Reference_To (Standard_False, Loc));
+
+ Prepend_To (Declarations (Func_Bod), Flag_Decl);
+ Analyze (Flag_Decl);
end;
end if;
- -- Find entity for subprogram
+ -- Build a simple_return_statement that returns the return object when
+ -- there is a statement sequence, or no expression, or the result will
+ -- be built in place. Note however that we currently do this for all
+ -- composite cases, even though nonlimited composite results are not yet
+ -- built in place (though we plan to do so eventually).
- Body_Id := Defining_Entity (N);
+ if Present (HSS)
+ or else Is_Composite_Type (Result_Subt)
+ or else No (Exp)
+ then
+ if No (HSS) then
+ Stmts := New_List;
- if Present (Corresponding_Spec (N)) then
- Spec_Id := Corresponding_Spec (N);
- else
- Spec_Id := Body_Id;
- end if;
+ -- If the extended return has a handled statement sequence, then wrap
+ -- it in a block and use the block as the first statement.
- -- Need poll on entry to subprogram if polling enabled. We only do this
- -- for non-empty subprograms, since it does not seem necessary to poll
- -- for a dummy null subprogram.
+ else
+ Stmts := New_List (
+ Make_Block_Statement (Loc,
+ Declarations => New_List,
+ Handled_Statement_Sequence => HSS));
+ end if;
+
+ -- If the result type contains tasks, we call Move_Activation_Chain.
+ -- Later, the cleanup code will call Complete_Master, which will
+ -- terminate any unactivated tasks belonging to the return statement
+ -- master. But Move_Activation_Chain updates their master to be that
+ -- of the caller, so they will not be terminated unless the return
+ -- statement completes unsuccessfully due to exception, abort, goto,
+ -- or exit. As a formality, we test whether the function requires the
+ -- result to be built in place, though that's necessarily true for
+ -- the case of result types with task parts.
+
+ if Is_Build_In_Place
+ and then Has_Task (Result_Subt)
+ then
+ -- The return expression is an aggregate for a complex type which
+ -- contains tasks. This particular case is left unexpanded since
+ -- the regular expansion would insert all temporaries and
+ -- initialization code in the wrong block.
+
+ if Nkind (Exp) = N_Aggregate then
+ Expand_N_Aggregate (Exp);
+ end if;
+
+ -- Do not move the activation chain if the return object does not
+ -- contain tasks.
+
+ if Has_Task (Etype (Ret_Obj_Id)) then
+ Append_To (Stmts, Move_Activation_Chain);
+ end if;
+ end if;
+
+ -- Update the state of the function right before the object is
+ -- returned.
+
+ if Is_Build_In_Place
+ and then Needs_Finalization (Etype (Ret_Obj_Id))
+ then
+ declare
+ Flag_Id : constant Entity_Id :=
+ Return_Flag_Or_Transient_Decl (Ret_Obj_Id);
+
+ begin
+ -- Generate:
+ -- Fnn := True;
+
+ Append_To (Stmts,
+ Make_Assignment_Statement (Loc,
+ Name => New_Reference_To (Flag_Id, Loc),
+ Expression => New_Reference_To (Standard_True, Loc)));
+ end;
+ end if;
+
+ -- Build a simple_return_statement that returns the return object
+
+ Return_Stmt :=
+ Make_Simple_Return_Statement (Loc,
+ Expression => New_Occurrence_Of (Ret_Obj_Id, Loc));
+ Append_To (Stmts, Return_Stmt);
+
+ HSS := Make_Handled_Sequence_Of_Statements (Loc, Stmts);
+ end if;
+
+ -- Case where we build a return statement block
+
+ if Present (HSS) then
+ Result :=
+ Make_Block_Statement (Loc,
+ Declarations => Return_Object_Declarations (N),
+ Handled_Statement_Sequence => HSS);
+
+ -- We set the entity of the new block statement to be that of the
+ -- return statement. This is necessary so that various fields, such
+ -- as Finalization_Chain_Entity carry over from the return statement
+ -- to the block. Note that this block is unusual, in that its entity
+ -- is an E_Return_Statement rather than an E_Block.
+
+ Set_Identifier
+ (Result, New_Occurrence_Of (Return_Statement_Entity (N), Loc));
+
+ -- If the object decl was already rewritten as a renaming, then we
+ -- don't want to do the object allocation and transformation of of
+ -- the return object declaration to a renaming. This case occurs
+ -- when the return object is initialized by a call to another
+ -- build-in-place function, and that function is responsible for
+ -- the allocation of the return object.
+
+ if Is_Build_In_Place
+ and then Nkind (Ret_Obj_Decl) = N_Object_Renaming_Declaration
+ then
+ pragma Assert
+ (Nkind (Original_Node (Ret_Obj_Decl)) = N_Object_Declaration
+ and then Is_Build_In_Place_Function_Call
+ (Expression (Original_Node (Ret_Obj_Decl))));
+
+ -- Return the build-in-place result by reference
+
+ Set_By_Ref (Return_Stmt);
+
+ elsif Is_Build_In_Place then
+
+ -- Locate the implicit access parameter associated with the
+ -- caller-supplied return object and convert the return
+ -- statement's return object declaration to a renaming of a
+ -- dereference of the access parameter. If the return object's
+ -- declaration includes an expression that has not already been
+ -- expanded as separate assignments, then add an assignment
+ -- statement to ensure the return object gets initialized.
+
+ -- declare
+ -- Result : T [:= <expression>];
+ -- begin
+ -- ...
+
+ -- is converted to
+
+ -- declare
+ -- Result : T renames FuncRA.all;
+ -- [Result := <expression;]
+ -- begin
+ -- ...
+
+ declare
+ Return_Obj_Id : constant Entity_Id :=
+ Defining_Identifier (Ret_Obj_Decl);
+ Return_Obj_Typ : constant Entity_Id := Etype (Return_Obj_Id);
+ Return_Obj_Expr : constant Node_Id :=
+ Expression (Ret_Obj_Decl);
+ Constr_Result : constant Boolean :=
+ Is_Constrained (Result_Subt);
+ Obj_Alloc_Formal : Entity_Id;
+ Object_Access : Entity_Id;
+ Obj_Acc_Deref : Node_Id;
+ Init_Assignment : Node_Id := Empty;
+
+ begin
+ -- Build-in-place results must be returned by reference
+
+ Set_By_Ref (Return_Stmt);
+
+ -- Retrieve the implicit access parameter passed by the caller
+
+ Object_Access :=
+ Build_In_Place_Formal (Par_Func, BIP_Object_Access);
+
+ -- If the return object's declaration includes an expression
+ -- and the declaration isn't marked as No_Initialization, then
+ -- we need to generate an assignment to the object and insert
+ -- it after the declaration before rewriting it as a renaming
+ -- (otherwise we'll lose the initialization). The case where
+ -- the result type is an interface (or class-wide interface)
+ -- is also excluded because the context of the function call
+ -- must be unconstrained, so the initialization will always
+ -- be done as part of an allocator evaluation (storage pool
+ -- or secondary stack), never to a constrained target object
+ -- passed in by the caller. Besides the assignment being
+ -- unneeded in this case, it avoids problems with trying to
+ -- generate a dispatching assignment when the return expression
+ -- is a nonlimited descendant of a limited interface (the
+ -- interface has no assignment operation).
+
+ if Present (Return_Obj_Expr)
+ and then not No_Initialization (Ret_Obj_Decl)
+ and then not Is_Interface (Return_Obj_Typ)
+ then
+ Init_Assignment :=
+ Make_Assignment_Statement (Loc,
+ Name => New_Reference_To (Return_Obj_Id, Loc),
+ Expression => Relocate_Node (Return_Obj_Expr));
+
+ Set_Etype (Name (Init_Assignment), Etype (Return_Obj_Id));
+ Set_Assignment_OK (Name (Init_Assignment));
+ Set_No_Ctrl_Actions (Init_Assignment);
+
+ Set_Parent (Name (Init_Assignment), Init_Assignment);
+ Set_Parent (Expression (Init_Assignment), Init_Assignment);
+
+ Set_Expression (Ret_Obj_Decl, Empty);
+
+ if Is_Class_Wide_Type (Etype (Return_Obj_Id))
+ and then not Is_Class_Wide_Type
+ (Etype (Expression (Init_Assignment)))
+ then
+ Rewrite (Expression (Init_Assignment),
+ Make_Type_Conversion (Loc,
+ Subtype_Mark =>
+ New_Occurrence_Of (Etype (Return_Obj_Id), Loc),
+ Expression =>
+ Relocate_Node (Expression (Init_Assignment))));
+ end if;
+
+ -- In the case of functions where the calling context can
+ -- determine the form of allocation needed, initialization
+ -- is done with each part of the if statement that handles
+ -- the different forms of allocation (this is true for
+ -- unconstrained and tagged result subtypes).
+
+ if Constr_Result
+ and then not Is_Tagged_Type (Underlying_Type (Result_Subt))
+ then
+ Insert_After (Ret_Obj_Decl, Init_Assignment);
+ end if;
+ end if;
+
+ -- When the function's subtype is unconstrained, a run-time
+ -- test is needed to determine the form of allocation to use
+ -- for the return object. The function has an implicit formal
+ -- parameter indicating this. If the BIP_Alloc_Form formal has
+ -- the value one, then the caller has passed access to an
+ -- existing object for use as the return object. If the value
+ -- is two, then the return object must be allocated on the
+ -- secondary stack. Otherwise, the object must be allocated in
+ -- a storage pool (currently only supported for the global
+ -- heap, user-defined storage pools TBD ???). We generate an
+ -- if statement to test the implicit allocation formal and
+ -- initialize a local access value appropriately, creating
+ -- allocators in the secondary stack and global heap cases.
+ -- The special formal also exists and must be tested when the
+ -- function has a tagged result, even when the result subtype
+ -- is constrained, because in general such functions can be
+ -- called in dispatching contexts and must be handled similarly
+ -- to functions with a class-wide result.
+
+ if not Constr_Result
+ or else Is_Tagged_Type (Underlying_Type (Result_Subt))
+ then
+ Obj_Alloc_Formal :=
+ Build_In_Place_Formal (Par_Func, BIP_Alloc_Form);
+
+ declare
+ Pool_Id : constant Entity_Id :=
+ Make_Temporary (Loc, 'P');
+ Alloc_Obj_Id : Entity_Id;
+ Alloc_Obj_Decl : Node_Id;
+ Alloc_If_Stmt : Node_Id;
+ Heap_Allocator : Node_Id;
+ Pool_Decl : Node_Id;
+ Pool_Allocator : Node_Id;
+ Ptr_Type_Decl : Node_Id;
+ Ref_Type : Entity_Id;
+ SS_Allocator : Node_Id;
+
+ begin
+ -- Reuse the itype created for the function's implicit
+ -- access formal. This avoids the need to create a new
+ -- access type here, plus it allows assigning the access
+ -- formal directly without applying a conversion.
+
+ -- Ref_Type := Etype (Object_Access);
+
+ -- Create an access type designating the function's
+ -- result subtype.
+
+ Ref_Type := Make_Temporary (Loc, 'A');
+
+ Ptr_Type_Decl :=
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Ref_Type,
+ Type_Definition =>
+ Make_Access_To_Object_Definition (Loc,
+ All_Present => True,
+ Subtype_Indication =>
+ New_Reference_To (Return_Obj_Typ, Loc)));
+
+ Insert_Before (Ret_Obj_Decl, Ptr_Type_Decl);
+
+ -- Create an access object that will be initialized to an
+ -- access value denoting the return object, either coming
+ -- from an implicit access value passed in by the caller
+ -- or from the result of an allocator.
+
+ Alloc_Obj_Id := Make_Temporary (Loc, 'R');
+ Set_Etype (Alloc_Obj_Id, Ref_Type);
+
+ Alloc_Obj_Decl :=
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Alloc_Obj_Id,
+ Object_Definition =>
+ New_Reference_To (Ref_Type, Loc));
+
+ Insert_Before (Ret_Obj_Decl, Alloc_Obj_Decl);
+
+ -- Create allocators for both the secondary stack and
+ -- global heap. If there's an initialization expression,
+ -- then create these as initialized allocators.
+
+ if Present (Return_Obj_Expr)
+ and then not No_Initialization (Ret_Obj_Decl)
+ then
+ -- Always use the type of the expression for the
+ -- qualified expression, rather than the result type.
+ -- In general we cannot always use the result type
+ -- for the allocator, because the expression might be
+ -- of a specific type, such as in the case of an
+ -- aggregate or even a nonlimited object when the
+ -- result type is a limited class-wide interface type.
+
+ Heap_Allocator :=
+ Make_Allocator (Loc,
+ Expression =>
+ Make_Qualified_Expression (Loc,
+ Subtype_Mark =>
+ New_Reference_To
+ (Etype (Return_Obj_Expr), Loc),
+ Expression =>
+ New_Copy_Tree (Return_Obj_Expr)));
+
+ else
+ -- If the function returns a class-wide type we cannot
+ -- use the return type for the allocator. Instead we
+ -- use the type of the expression, which must be an
+ -- aggregate of a definite type.
+
+ if Is_Class_Wide_Type (Return_Obj_Typ) then
+ Heap_Allocator :=
+ Make_Allocator (Loc,
+ Expression =>
+ New_Reference_To
+ (Etype (Return_Obj_Expr), Loc));
+ else
+ Heap_Allocator :=
+ Make_Allocator (Loc,
+ Expression =>
+ New_Reference_To (Return_Obj_Typ, Loc));
+ end if;
+
+ -- If the object requires default initialization then
+ -- that will happen later following the elaboration of
+ -- the object renaming. If we don't turn it off here
+ -- then the object will be default initialized twice.
+
+ Set_No_Initialization (Heap_Allocator);
+ end if;
+
+ -- The Pool_Allocator is just like the Heap_Allocator,
+ -- except we set Storage_Pool and Procedure_To_Call so
+ -- it will use the user-defined storage pool.
+
+ Pool_Allocator := New_Copy_Tree (Heap_Allocator);
+
+ -- Do not generate the renaming of the build-in-place
+ -- pool parameter on .NET/JVM/ZFP because the parameter
+ -- is not created in the first place.
+
+ if VM_Target = No_VM
+ and then RTE_Available (RE_Root_Storage_Pool_Ptr)
+ then
+ Pool_Decl :=
+ Make_Object_Renaming_Declaration (Loc,
+ Defining_Identifier => Pool_Id,
+ Subtype_Mark =>
+ New_Reference_To
+ (RTE (RE_Root_Storage_Pool), Loc),
+ Name =>
+ Make_Explicit_Dereference (Loc,
+ New_Reference_To
+ (Build_In_Place_Formal
+ (Par_Func, BIP_Storage_Pool), Loc)));
+ Set_Storage_Pool (Pool_Allocator, Pool_Id);
+ Set_Procedure_To_Call
+ (Pool_Allocator, RTE (RE_Allocate_Any));
+ else
+ Pool_Decl := Make_Null_Statement (Loc);
+ end if;
+
+ -- If the No_Allocators restriction is active, then only
+ -- an allocator for secondary stack allocation is needed.
+ -- It's OK for such allocators to have Comes_From_Source
+ -- set to False, because gigi knows not to flag them as
+ -- being a violation of No_Implicit_Heap_Allocations.
+
+ if Restriction_Active (No_Allocators) then
+ SS_Allocator := Heap_Allocator;
+ Heap_Allocator := Make_Null (Loc);
+ Pool_Allocator := Make_Null (Loc);
+
+ -- Otherwise the heap and pool allocators may be needed,
+ -- so we make another allocator for secondary stack
+ -- allocation.
+
+ else
+ SS_Allocator := New_Copy_Tree (Heap_Allocator);
+
+ -- The heap and pool allocators are marked as
+ -- Comes_From_Source since they correspond to an
+ -- explicit user-written allocator (that is, it will
+ -- only be executed on behalf of callers that call the
+ -- function as initialization for such an allocator).
+ -- Prevents errors when No_Implicit_Heap_Allocations
+ -- is in force.
+
+ Set_Comes_From_Source (Heap_Allocator, True);
+ Set_Comes_From_Source (Pool_Allocator, True);
+ end if;
+
+ -- The allocator is returned on the secondary stack. We
+ -- don't do this on VM targets, since the SS is not used.
+
+ if VM_Target = No_VM then
+ Set_Storage_Pool (SS_Allocator, RTE (RE_SS_Pool));
+ Set_Procedure_To_Call
+ (SS_Allocator, RTE (RE_SS_Allocate));
+
+ -- The allocator is returned on the secondary stack,
+ -- so indicate that the function return, as well as
+ -- the block that encloses the allocator, must not
+ -- release it. The flags must be set now because
+ -- the decision to use the secondary stack is done
+ -- very late in the course of expanding the return
+ -- statement, past the point where these flags are
+ -- normally set.
+
+ Set_Sec_Stack_Needed_For_Return (Par_Func);
+ Set_Sec_Stack_Needed_For_Return
+ (Return_Statement_Entity (N));
+ Set_Uses_Sec_Stack (Par_Func);
+ Set_Uses_Sec_Stack (Return_Statement_Entity (N));
+ end if;
+
+ -- Create an if statement to test the BIP_Alloc_Form
+ -- formal and initialize the access object to either the
+ -- BIP_Object_Access formal (BIP_Alloc_Form =
+ -- Caller_Allocation), the result of allocating the
+ -- object in the secondary stack (BIP_Alloc_Form =
+ -- Secondary_Stack), or else an allocator to create the
+ -- return object in the heap or user-defined pool
+ -- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
+
+ -- ??? An unchecked type conversion must be made in the
+ -- case of assigning the access object formal to the
+ -- local access object, because a normal conversion would
+ -- be illegal in some cases (such as converting access-
+ -- to-unconstrained to access-to-constrained), but the
+ -- the unchecked conversion will presumably fail to work
+ -- right in just such cases. It's not clear at all how to
+ -- handle this. ???
+
+ Alloc_If_Stmt :=
+ Make_If_Statement (Loc,
+ Condition =>
+ Make_Op_Eq (Loc,
+ Left_Opnd =>
+ New_Reference_To (Obj_Alloc_Formal, Loc),
+ Right_Opnd =>
+ Make_Integer_Literal (Loc,
+ UI_From_Int (BIP_Allocation_Form'Pos
+ (Caller_Allocation)))),
+
+ Then_Statements => New_List (
+ Make_Assignment_Statement (Loc,
+ Name =>
+ New_Reference_To (Alloc_Obj_Id, Loc),
+ Expression =>
+ Make_Unchecked_Type_Conversion (Loc,
+ Subtype_Mark =>
+ New_Reference_To (Ref_Type, Loc),
+ Expression =>
+ New_Reference_To (Object_Access, Loc)))),
+
+ Elsif_Parts => New_List (
+ Make_Elsif_Part (Loc,
+ Condition =>
+ Make_Op_Eq (Loc,
+ Left_Opnd =>
+ New_Reference_To (Obj_Alloc_Formal, Loc),
+ Right_Opnd =>
+ Make_Integer_Literal (Loc,
+ UI_From_Int (BIP_Allocation_Form'Pos
+ (Secondary_Stack)))),
+
+ Then_Statements => New_List (
+ Make_Assignment_Statement (Loc,
+ Name =>
+ New_Reference_To (Alloc_Obj_Id, Loc),
+ Expression => SS_Allocator))),
+
+ Make_Elsif_Part (Loc,
+ Condition =>
+ Make_Op_Eq (Loc,
+ Left_Opnd =>
+ New_Reference_To (Obj_Alloc_Formal, Loc),
+ Right_Opnd =>
+ Make_Integer_Literal (Loc,
+ UI_From_Int (BIP_Allocation_Form'Pos
+ (Global_Heap)))),
+
+ Then_Statements => New_List (
+ Build_Heap_Allocator
+ (Temp_Id => Alloc_Obj_Id,
+ Temp_Typ => Ref_Type,
+ Func_Id => Par_Func,
+ Ret_Typ => Return_Obj_Typ,
+ Alloc_Expr => Heap_Allocator)))),
+
+ Else_Statements => New_List (
+ Pool_Decl,
+ Build_Heap_Allocator
+ (Temp_Id => Alloc_Obj_Id,
+ Temp_Typ => Ref_Type,
+ Func_Id => Par_Func,
+ Ret_Typ => Return_Obj_Typ,
+ Alloc_Expr => Pool_Allocator)));
+
+ -- If a separate initialization assignment was created
+ -- earlier, append that following the assignment of the
+ -- implicit access formal to the access object, to ensure
+ -- that the return object is initialized in that case. In
+ -- this situation, the target of the assignment must be
+ -- rewritten to denote a dereference of the access to the
+ -- return object passed in by the caller.
+
+ if Present (Init_Assignment) then
+ Rewrite (Name (Init_Assignment),
+ Make_Explicit_Dereference (Loc,
+ Prefix => New_Reference_To (Alloc_Obj_Id, Loc)));
+
+ Set_Etype
+ (Name (Init_Assignment), Etype (Return_Obj_Id));
+
+ Append_To
+ (Then_Statements (Alloc_If_Stmt), Init_Assignment);
+ end if;
+
+ Insert_Before (Ret_Obj_Decl, Alloc_If_Stmt);
+
+ -- Remember the local access object for use in the
+ -- dereference of the renaming created below.
+
+ Object_Access := Alloc_Obj_Id;
+ end;
+ end if;
+
+ -- Replace the return object declaration with a renaming of a
+ -- dereference of the access value designating the return
+ -- object.
+
+ Obj_Acc_Deref :=
+ Make_Explicit_Dereference (Loc,
+ Prefix => New_Reference_To (Object_Access, Loc));
+
+ Rewrite (Ret_Obj_Decl,
+ Make_Object_Renaming_Declaration (Loc,
+ Defining_Identifier => Return_Obj_Id,
+ Access_Definition => Empty,
+ Subtype_Mark =>
+ New_Occurrence_Of (Return_Obj_Typ, Loc),
+ Name => Obj_Acc_Deref));
+
+ Set_Renamed_Object (Return_Obj_Id, Obj_Acc_Deref);
+ end;
+ end if;
+
+ -- Case where we do not build a block
+
+ else
+ -- We're about to drop Return_Object_Declarations on the floor, so
+ -- we need to insert it, in case it got expanded into useful code.
+ -- Remove side effects from expression, which may be duplicated in
+ -- subsequent checks (see Expand_Simple_Function_Return).
+
+ Insert_List_Before (N, Return_Object_Declarations (N));
+ Remove_Side_Effects (Exp);
+
+ -- Build simple_return_statement that returns the expression directly
+
+ Return_Stmt := Make_Simple_Return_Statement (Loc, Expression => Exp);
+ Result := Return_Stmt;
+ end if;
+
+ -- Set the flag to prevent infinite recursion
+
+ Set_Comes_From_Extended_Return_Statement (Return_Stmt);
+
+ Rewrite (N, Result);
+ Analyze (N);
+ end Expand_N_Extended_Return_Statement;
+
+ ----------------------------
+ -- Expand_N_Function_Call --
+ ----------------------------
+
+ procedure Expand_N_Function_Call (N : Node_Id) is
+ begin
+ Expand_Call (N);
+
+ -- If the return value of a foreign compiled function is VAX Float, then
+ -- expand the return (adjusts the location of the return value on
+ -- Alpha/VMS, no-op everywhere else).
+ -- Comes_From_Source intercepts recursive expansion.
+
+ if Vax_Float (Etype (N))
+ and then Nkind (N) = N_Function_Call
+ and then Present (Name (N))
+ and then Present (Entity (Name (N)))
+ and then Has_Foreign_Convention (Entity (Name (N)))
+ and then Comes_From_Source (Parent (N))
+ then
+ Expand_Vax_Foreign_Return (N);
+ end if;
+ end Expand_N_Function_Call;
+
+ ---------------------------------------
+ -- Expand_N_Procedure_Call_Statement --
+ ---------------------------------------
+
+ procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
+ begin
+ Expand_Call (N);
+ end Expand_N_Procedure_Call_Statement;
+
+ --------------------------------------
+ -- Expand_N_Simple_Return_Statement --
+ --------------------------------------
+
+ procedure Expand_N_Simple_Return_Statement (N : Node_Id) is
+ begin
+ -- Defend against previous errors (i.e. the return statement calls a
+ -- function that is not available in configurable runtime).
+
+ if Present (Expression (N))
+ and then Nkind (Expression (N)) = N_Empty
+ then
+ return;
+ end if;
+
+ -- Distinguish the function and non-function cases:
+
+ case Ekind (Return_Applies_To (Return_Statement_Entity (N))) is
+
+ when E_Function |
+ E_Generic_Function =>
+ Expand_Simple_Function_Return (N);
+
+ when E_Procedure |
+ E_Generic_Procedure |
+ E_Entry |
+ E_Entry_Family |
+ E_Return_Statement =>
+ Expand_Non_Function_Return (N);
+
+ when others =>
+ raise Program_Error;
+ end case;
+
+ exception
+ when RE_Not_Available =>
+ return;
+ end Expand_N_Simple_Return_Statement;
+
+ ------------------------------
+ -- Expand_N_Subprogram_Body --
+ ------------------------------
+
+ -- Add poll call if ATC polling is enabled, unless the body will be inlined
+ -- by the back-end.
+
+ -- Add dummy push/pop label nodes at start and end to clear any local
+ -- exception indications if local-exception-to-goto optimization is active.
+
+ -- Add return statement if last statement in body is not a return statement
+ -- (this makes things easier on Gigi which does not want to have to handle
+ -- a missing return).
+
+ -- Add call to Activate_Tasks if body is a task activator
+
+ -- Deal with possible detection of infinite recursion
+
+ -- Eliminate body completely if convention stubbed
+
+ -- Encode entity names within body, since we will not need to reference
+ -- these entities any longer in the front end.
+
+ -- Initialize scalar out parameters if Initialize/Normalize_Scalars
+
+ -- Reset Pure indication if any parameter has root type System.Address
+ -- or has any parameters of limited types, where limited means that the
+ -- run-time view is limited (i.e. the full type is limited).
+
+ -- Wrap thread body
+
+ procedure Expand_N_Subprogram_Body (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
+ H : constant Node_Id := Handled_Statement_Sequence (N);
+ Body_Id : Entity_Id;
+ Except_H : Node_Id;
+ L : List_Id;
+ Spec_Id : Entity_Id;
+
+ procedure Add_Return (S : List_Id);
+ -- Append a return statement to the statement sequence S if the last
+ -- statement is not already a return or a goto statement. Note that
+ -- the latter test is not critical, it does not matter if we add a few
+ -- extra returns, since they get eliminated anyway later on.
+
+ ----------------
+ -- Add_Return --
+ ----------------
+
+ procedure Add_Return (S : List_Id) is
+ Last_Stm : Node_Id;
+ Loc : Source_Ptr;
+
+ begin
+ -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
+ -- not relevant in this context since they are not executable.
+
+ Last_Stm := Last (S);
+ while Nkind (Last_Stm) in N_Pop_xxx_Label loop
+ Prev (Last_Stm);
+ end loop;
+
+ -- Now insert return unless last statement is a transfer
+
+ if not Is_Transfer (Last_Stm) then
+
+ -- The source location for the return is the end label of the
+ -- procedure if present. Otherwise use the sloc of the last
+ -- statement in the list. If the list comes from a generated
+ -- exception handler and we are not debugging generated code,
+ -- all the statements within the handler are made invisible
+ -- to the debugger.
+
+ if Nkind (Parent (S)) = N_Exception_Handler
+ and then not Comes_From_Source (Parent (S))
+ then
+ Loc := Sloc (Last_Stm);
+ elsif Present (End_Label (H)) then
+ Loc := Sloc (End_Label (H));
+ else
+ Loc := Sloc (Last_Stm);
+ end if;
+
+ declare
+ Rtn : constant Node_Id := Make_Simple_Return_Statement (Loc);
+
+ begin
+ -- Append return statement, and set analyzed manually. We can't
+ -- call Analyze on this return since the scope is wrong.
+
+ -- Note: it almost works to push the scope and then do the
+ -- Analyze call, but something goes wrong in some weird cases
+ -- and it is not worth worrying about ???
+
+ Append_To (S, Rtn);
+ Set_Analyzed (Rtn);
+
+ -- Call _Postconditions procedure if appropriate. We need to
+ -- do this explicitly because we did not analyze the generated
+ -- return statement above, so the call did not get inserted.
+
+ if Ekind (Spec_Id) = E_Procedure
+ and then Has_Postconditions (Spec_Id)
+ then
+ pragma Assert (Present (Postcondition_Proc (Spec_Id)));
+ Insert_Action (Rtn,
+ Make_Procedure_Call_Statement (Loc,
+ Name =>
+ New_Reference_To (Postcondition_Proc (Spec_Id), Loc)));
+ end if;
+ end;
+ end if;
+ end Add_Return;
+
+ -- Start of processing for Expand_N_Subprogram_Body
+
+ begin
+ -- Set L to either the list of declarations if present, or to the list
+ -- of statements if no declarations are present. This is used to insert
+ -- new stuff at the start.
+
+ if Is_Non_Empty_List (Declarations (N)) then
+ L := Declarations (N);
+ else
+ L := Statements (H);
+ end if;
+
+ -- If local-exception-to-goto optimization active, insert dummy push
+ -- statements at start, and dummy pop statements at end, but inhibit
+ -- this if we have No_Exception_Handlers, since they are useless and
+ -- intefere with analysis, e.g. by codepeer.
+
+ if (Debug_Flag_Dot_G
+ or else Restriction_Active (No_Exception_Propagation))
+ and then not Restriction_Active (No_Exception_Handlers)
+ and then not CodePeer_Mode
+ and then Is_Non_Empty_List (L)
+ then
+ declare
+ FS : constant Node_Id := First (L);
+ FL : constant Source_Ptr := Sloc (FS);
+ LS : Node_Id;
+ LL : Source_Ptr;
+
+ begin
+ -- LS points to either last statement, if statements are present
+ -- or to the last declaration if there are no statements present.
+ -- It is the node after which the pop's are generated.
+
+ if Is_Non_Empty_List (Statements (H)) then
+ LS := Last (Statements (H));
+ else
+ LS := Last (L);
+ end if;
+
+ LL := Sloc (LS);
+
+ Insert_List_Before_And_Analyze (FS, New_List (
+ Make_Push_Constraint_Error_Label (FL),
+ Make_Push_Program_Error_Label (FL),
+ Make_Push_Storage_Error_Label (FL)));
+
+ Insert_List_After_And_Analyze (LS, New_List (
+ Make_Pop_Constraint_Error_Label (LL),
+ Make_Pop_Program_Error_Label (LL),
+ Make_Pop_Storage_Error_Label (LL)));
+ end;
+ end if;
+
+ -- Find entity for subprogram
+
+ Body_Id := Defining_Entity (N);
+
+ if Present (Corresponding_Spec (N)) then
+ Spec_Id := Corresponding_Spec (N);
+ else
+ Spec_Id := Body_Id;
+ end if;
+
+ -- Need poll on entry to subprogram if polling enabled. We only do this
+ -- for non-empty subprograms, since it does not seem necessary to poll
+ -- for a dummy null subprogram.
if Is_Non_Empty_List (L) then
begin
F := First_Formal (Spec_Id);
while Present (F) loop
- if Is_Descendent_Of_Address (Etype (F)) then
+ if Is_Descendent_Of_Address (Etype (F))
+
+ -- Note that this test is being made in the body of the
+ -- subprogram, not the spec, so we are testing the full
+ -- type for being limited here, as required.
+
+ or else Is_Limited_Type (Etype (F))
+ then
Set_Is_Pure (Spec_Id, False);
if Spec_Id /= Body_Id then
Set_Declarations (N, Empty_List);
Set_Handled_Statement_Sequence (N,
Make_Handled_Sequence_Of_Statements (Loc,
- Statements => New_List (
- Make_Null_Statement (Loc))));
+ Statements => New_List (Make_Null_Statement (Loc))));
return;
end if;
end if;
then
null;
- elsif Is_Inherently_Limited_Type (Typ) then
+ elsif Is_Immutably_Limited_Type (Typ) then
Set_Returns_By_Ref (Spec_Id);
elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
Prot_Id : Entity_Id;
begin
+ -- In SPARK, subprogram declarations are only allowed in package
+ -- specifications.
+
+ if Nkind (Parent (N)) /= N_Package_Specification then
+ if Nkind (Parent (N)) = N_Compilation_Unit then
+ Check_SPARK_Restriction
+ ("subprogram declaration is not a library item", N);
+
+ elsif Present (Next (N))
+ and then Nkind (Next (N)) = N_Pragma
+ and then Get_Pragma_Id (Pragma_Name (Next (N))) = Pragma_Import
+ then
+ -- In SPARK, subprogram declarations are also permitted in
+ -- declarative parts when immediately followed by a corresponding
+ -- pragma Import. We only check here that there is some pragma
+ -- Import.
+
+ null;
+ else
+ Check_SPARK_Restriction
+ ("subprogram declaration is not allowed here", N);
+ end if;
+ end if;
+
-- Deal with case of protected subprogram. Do not generate protected
-- operation if operation is flagged as eliminated.
Push_Scope (Scope (Scop));
Analyze (Prot_Decl);
- Insert_Actions (N, Freeze_Entity (Prot_Id, Loc));
+ Freeze_Before (N, Prot_Id);
Set_Protected_Body_Subprogram (Subp, Prot_Id);
-- Create protected operation as well. Even though the operation
Pop_Scope;
end if;
- -- Ada 2005 (AI-348): Generate body for a null procedure.
- -- In most cases this is superfluous because calls to it
- -- will be automatically inlined, but we definitely need
- -- the body if preconditions for the procedure are present.
+ -- Ada 2005 (AI-348): Generate body for a null procedure. In most
+ -- cases this is superfluous because calls to it will be automatically
+ -- inlined, but we definitely need the body if preconditions for the
+ -- procedure are present.
elsif Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
end if;
end Expand_N_Subprogram_Declaration;
+ --------------------------------
+ -- Expand_Non_Function_Return --
+ --------------------------------
+
+ procedure Expand_Non_Function_Return (N : Node_Id) is
+ pragma Assert (No (Expression (N)));
+
+ Loc : constant Source_Ptr := Sloc (N);
+ Scope_Id : Entity_Id :=
+ Return_Applies_To (Return_Statement_Entity (N));
+ Kind : constant Entity_Kind := Ekind (Scope_Id);
+ Call : Node_Id;
+ Acc_Stat : Node_Id;
+ Goto_Stat : Node_Id;
+ Lab_Node : Node_Id;
+
+ begin
+ -- Call _Postconditions procedure if procedure with active
+ -- postconditions. Here, we use the Postcondition_Proc attribute,
+ -- which is needed for implicitly-generated returns. Functions
+ -- never have implicitly-generated returns, and there's no
+ -- room for Postcondition_Proc in E_Function, so we look up the
+ -- identifier Name_uPostconditions for function returns (see
+ -- Expand_Simple_Function_Return).
+
+ if Ekind (Scope_Id) = E_Procedure
+ and then Has_Postconditions (Scope_Id)
+ then
+ pragma Assert (Present (Postcondition_Proc (Scope_Id)));
+ Insert_Action (N,
+ Make_Procedure_Call_Statement (Loc,
+ Name => New_Reference_To (Postcondition_Proc (Scope_Id), Loc)));
+ end if;
+
+ -- If it is a return from a procedure do no extra steps
+
+ if Kind = E_Procedure or else Kind = E_Generic_Procedure then
+ return;
+
+ -- If it is a nested return within an extended one, replace it with a
+ -- return of the previously declared return object.
+
+ elsif Kind = E_Return_Statement then
+ Rewrite (N,
+ Make_Simple_Return_Statement (Loc,
+ Expression =>
+ New_Occurrence_Of (First_Entity (Scope_Id), Loc)));
+ Set_Comes_From_Extended_Return_Statement (N);
+ Set_Return_Statement_Entity (N, Scope_Id);
+ Expand_Simple_Function_Return (N);
+ return;
+ end if;
+
+ pragma Assert (Is_Entry (Scope_Id));
+
+ -- Look at the enclosing block to see whether the return is from an
+ -- accept statement or an entry body.
+
+ for J in reverse 0 .. Scope_Stack.Last loop
+ Scope_Id := Scope_Stack.Table (J).Entity;
+ exit when Is_Concurrent_Type (Scope_Id);
+ end loop;
+
+ -- If it is a return from accept statement it is expanded as call to
+ -- RTS Complete_Rendezvous and a goto to the end of the accept body.
+
+ -- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
+ -- Expand_N_Accept_Alternative in exp_ch9.adb)
+
+ if Is_Task_Type (Scope_Id) then
+
+ Call :=
+ Make_Procedure_Call_Statement (Loc,
+ Name => New_Reference_To (RTE (RE_Complete_Rendezvous), Loc));
+ Insert_Before (N, Call);
+ -- why not insert actions here???
+ Analyze (Call);
+
+ Acc_Stat := Parent (N);
+ while Nkind (Acc_Stat) /= N_Accept_Statement loop
+ Acc_Stat := Parent (Acc_Stat);
+ end loop;
+
+ Lab_Node := Last (Statements
+ (Handled_Statement_Sequence (Acc_Stat)));
+
+ Goto_Stat := Make_Goto_Statement (Loc,
+ Name => New_Occurrence_Of
+ (Entity (Identifier (Lab_Node)), Loc));
+
+ Set_Analyzed (Goto_Stat);
+
+ Rewrite (N, Goto_Stat);
+ Analyze (N);
+
+ -- If it is a return from an entry body, put a Complete_Entry_Body call
+ -- in front of the return.
+
+ elsif Is_Protected_Type (Scope_Id) then
+ Call :=
+ Make_Procedure_Call_Statement (Loc,
+ Name =>
+ New_Reference_To (RTE (RE_Complete_Entry_Body), Loc),
+ Parameter_Associations => New_List (
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Reference_To
+ (Find_Protection_Object (Current_Scope), Loc),
+ Attribute_Name => Name_Unchecked_Access)));
+
+ Insert_Before (N, Call);
+ Analyze (Call);
+ end if;
+ end Expand_Non_Function_Return;
+
---------------------------------------
-- Expand_Protected_Object_Reference --
---------------------------------------
Proc : Entity_Id;
begin
- Rec :=
- Make_Identifier (Loc,
- Chars => Name_uObject);
+ Rec := Make_Identifier (Loc, Name_uObject);
Set_Etype (Rec, Corresponding_Record_Type (Scop));
-- Find enclosing protected operation, and retrieve its first parameter,
Decls := New_List (
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Obj_Ptr,
- Type_Definition =>
+ Type_Definition =>
Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
New_Reference_To
(Corresponding_Record_Type (Scop), Loc))));
Insert_Actions (N, Decls);
- Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
+ Freeze_Before (N, Obj_Ptr);
Rec :=
Make_Explicit_Dereference (Loc,
- Unchecked_Convert_To (Obj_Ptr,
- New_Occurrence_Of (Param, Loc)));
+ Prefix =>
+ Unchecked_Convert_To (Obj_Ptr,
+ New_Occurrence_Of (Param, Loc)));
-- Analyze new actual. Other actuals in calls are already analyzed
-- and the list of actuals is not reanalyzed after rewriting.
Rec : Node_Id;
begin
- -- If the protected object is not an enclosing scope, this is
- -- an inter-object function call. Inter-object procedure
- -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
- -- The call is intra-object only if the subprogram being
- -- called is in the protected body being compiled, and if the
- -- protected object in the call is statically the enclosing type.
- -- The object may be an component of some other data structure,
- -- in which case this must be handled as an inter-object call.
+ -- If the protected object is not an enclosing scope, this is an inter-
+ -- object function call. Inter-object procedure calls are expanded by
+ -- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
+ -- subprogram being called is in the protected body being compiled, and
+ -- if the protected object in the call is statically the enclosing type.
+ -- The object may be an component of some other data structure, in which
+ -- case this must be handled as an inter-object call.
if not In_Open_Scopes (Scop)
or else not Is_Entity_Name (Name (N))
if Nkind (Name (N)) = N_Selected_Component then
Rec := Prefix (Name (N));
- else
- pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
- Rec := Prefix (Prefix (Name (N)));
- end if;
+ else
+ pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
+ Rec := Prefix (Prefix (Name (N)));
+ end if;
+
+ Build_Protected_Subprogram_Call (N,
+ Name => New_Occurrence_Of (Subp, Sloc (N)),
+ Rec => Convert_Concurrent (Rec, Etype (Rec)),
+ External => True);
+
+ else
+ Rec := Expand_Protected_Object_Reference (N, Scop);
+
+ if No (Rec) then
+ return;
+ end if;
+
+ Build_Protected_Subprogram_Call (N,
+ Name => Name (N),
+ Rec => Rec,
+ External => False);
+
+ end if;
+
+ -- If it is a function call it can appear in elaboration code and
+ -- the called entity must be frozen here.
+
+ if Ekind (Subp) = E_Function then
+ Freeze_Expression (Name (N));
+ end if;
+
+ -- Analyze and resolve the new call. The actuals have already been
+ -- resolved, but expansion of a function call will add extra actuals
+ -- if needed. Analysis of a procedure call already includes resolution.
+
+ Analyze (N);
+
+ if Ekind (Subp) = E_Function then
+ Resolve (N, Etype (Subp));
+ end if;
+ end Expand_Protected_Subprogram_Call;
+
+ --------------------------------------------
+ -- Has_Unconstrained_Access_Discriminants --
+ --------------------------------------------
+
+ function Has_Unconstrained_Access_Discriminants
+ (Subtyp : Entity_Id) return Boolean
+ is
+ Discr : Entity_Id;
+
+ begin
+ if Has_Discriminants (Subtyp)
+ and then not Is_Constrained (Subtyp)
+ then
+ Discr := First_Discriminant (Subtyp);
+ while Present (Discr) loop
+ if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then
+ return True;
+ end if;
+
+ Next_Discriminant (Discr);
+ end loop;
+ end if;
+
+ return False;
+ end Has_Unconstrained_Access_Discriminants;
+
+ -----------------------------------
+ -- Expand_Simple_Function_Return --
+ -----------------------------------
+
+ -- The "simple" comes from the syntax rule simple_return_statement. The
+ -- semantics are not at all simple!
+
+ procedure Expand_Simple_Function_Return (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
+
+ Scope_Id : constant Entity_Id :=
+ Return_Applies_To (Return_Statement_Entity (N));
+ -- The function we are returning from
+
+ R_Type : constant Entity_Id := Etype (Scope_Id);
+ -- The result type of the function
+
+ Utyp : constant Entity_Id := Underlying_Type (R_Type);
+
+ Exp : constant Node_Id := Expression (N);
+ pragma Assert (Present (Exp));
+
+ Exptyp : constant Entity_Id := Etype (Exp);
+ -- The type of the expression (not necessarily the same as R_Type)
+
+ Subtype_Ind : Node_Id;
+ -- If the result type of the function is class-wide and the expression
+ -- has a specific type, then we use the expression's type as the type of
+ -- the return object. In cases where the expression is an aggregate that
+ -- is built in place, this avoids the need for an expensive conversion
+ -- of the return object to the specific type on assignments to the
+ -- individual components.
+
+ begin
+ if Is_Class_Wide_Type (R_Type)
+ and then not Is_Class_Wide_Type (Etype (Exp))
+ then
+ Subtype_Ind := New_Occurrence_Of (Etype (Exp), Loc);
+ else
+ Subtype_Ind := New_Occurrence_Of (R_Type, Loc);
+ end if;
+
+ -- For the case of a simple return that does not come from an extended
+ -- return, in the case of Ada 2005 where we are returning a limited
+ -- type, we rewrite "return <expression>;" to be:
+
+ -- return _anon_ : <return_subtype> := <expression>
+
+ -- The expansion produced by Expand_N_Extended_Return_Statement will
+ -- contain simple return statements (for example, a block containing
+ -- simple return of the return object), which brings us back here with
+ -- Comes_From_Extended_Return_Statement set. The reason for the barrier
+ -- checking for a simple return that does not come from an extended
+ -- return is to avoid this infinite recursion.
+
+ -- The reason for this design is that for Ada 2005 limited returns, we
+ -- need to reify the return object, so we can build it "in place", and
+ -- we need a block statement to hang finalization and tasking stuff.
+
+ -- ??? In order to avoid disruption, we avoid translating to extended
+ -- return except in the cases where we really need to (Ada 2005 for
+ -- inherently limited). We might prefer to do this translation in all
+ -- cases (except perhaps for the case of Ada 95 inherently limited),
+ -- in order to fully exercise the Expand_N_Extended_Return_Statement
+ -- code. This would also allow us to do the build-in-place optimization
+ -- for efficiency even in cases where it is semantically not required.
+
+ -- As before, we check the type of the return expression rather than the
+ -- return type of the function, because the latter may be a limited
+ -- class-wide interface type, which is not a limited type, even though
+ -- the type of the expression may be.
+
+ if not Comes_From_Extended_Return_Statement (N)
+ and then Is_Immutably_Limited_Type (Etype (Expression (N)))
+ and then Ada_Version >= Ada_2005
+ and then not Debug_Flag_Dot_L
+ then
+ declare
+ Return_Object_Entity : constant Entity_Id :=
+ Make_Temporary (Loc, 'R', Exp);
+ Obj_Decl : constant Node_Id :=
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Return_Object_Entity,
+ Object_Definition => Subtype_Ind,
+ Expression => Exp);
+
+ Ext : constant Node_Id := Make_Extended_Return_Statement (Loc,
+ Return_Object_Declarations => New_List (Obj_Decl));
+ -- Do not perform this high-level optimization if the result type
+ -- is an interface because the "this" pointer must be displaced.
+
+ begin
+ Rewrite (N, Ext);
+ Analyze (N);
+ return;
+ end;
+ end if;
+
+ -- Here we have a simple return statement that is part of the expansion
+ -- of an extended return statement (either written by the user, or
+ -- generated by the above code).
+
+ -- Always normalize C/Fortran boolean result. This is not always needed,
+ -- but it seems a good idea to minimize the passing around of non-
+ -- normalized values, and in any case this handles the processing of
+ -- barrier functions for protected types, which turn the condition into
+ -- a return statement.
+
+ if Is_Boolean_Type (Exptyp)
+ and then Nonzero_Is_True (Exptyp)
+ then
+ Adjust_Condition (Exp);
+ Adjust_Result_Type (Exp, Exptyp);
+ end if;
+
+ -- Do validity check if enabled for returns
+
+ if Validity_Checks_On
+ and then Validity_Check_Returns
+ then
+ Ensure_Valid (Exp);
+ end if;
+
+ -- Check the result expression of a scalar function against the subtype
+ -- of the function by inserting a conversion. This conversion must
+ -- eventually be performed for other classes of types, but for now it's
+ -- only done for scalars.
+ -- ???
+
+ if Is_Scalar_Type (Exptyp) then
+ Rewrite (Exp, Convert_To (R_Type, Exp));
+
+ -- The expression is resolved to ensure that the conversion gets
+ -- expanded to generate a possible constraint check.
+
+ Analyze_And_Resolve (Exp, R_Type);
+ end if;
+
+ -- Deal with returning variable length objects and controlled types
+
+ -- Nothing to do if we are returning by reference, or this is not a
+ -- type that requires special processing (indicated by the fact that
+ -- it requires a cleanup scope for the secondary stack case).
+
+ if Is_Immutably_Limited_Type (Exptyp)
+ or else Is_Limited_Interface (Exptyp)
+ then
+ null;
+
+ elsif not Requires_Transient_Scope (R_Type) then
+
+ -- Mutable records with no variable length components are not
+ -- returned on the sec-stack, so we need to make sure that the
+ -- backend will only copy back the size of the actual value, and not
+ -- the maximum size. We create an actual subtype for this purpose.
+
+ declare
+ Ubt : constant Entity_Id := Underlying_Type (Base_Type (Exptyp));
+ Decl : Node_Id;
+ Ent : Entity_Id;
+ begin
+ if Has_Discriminants (Ubt)
+ and then not Is_Constrained (Ubt)
+ and then not Has_Unchecked_Union (Ubt)
+ then
+ Decl := Build_Actual_Subtype (Ubt, Exp);
+ Ent := Defining_Identifier (Decl);
+ Insert_Action (Exp, Decl);
+ Rewrite (Exp, Unchecked_Convert_To (Ent, Exp));
+ Analyze_And_Resolve (Exp);
+ end if;
+ end;
+
+ -- Here if secondary stack is used
+
+ else
+ -- Make sure that no surrounding block will reclaim the secondary
+ -- stack on which we are going to put the result. Not only may this
+ -- introduce secondary stack leaks but worse, if the reclamation is
+ -- done too early, then the result we are returning may get
+ -- clobbered.
+
+ declare
+ S : Entity_Id;
+ begin
+ S := Current_Scope;
+ while Ekind (S) = E_Block or else Ekind (S) = E_Loop loop
+ Set_Sec_Stack_Needed_For_Return (S, True);
+ S := Enclosing_Dynamic_Scope (S);
+ end loop;
+ end;
+
+ -- Optimize the case where the result is a function call. In this
+ -- case either the result is already on the secondary stack, or is
+ -- already being returned with the stack pointer depressed and no
+ -- further processing is required except to set the By_Ref flag
+ -- to ensure that gigi does not attempt an extra unnecessary copy.
+ -- (actually not just unnecessary but harmfully wrong in the case
+ -- of a controlled type, where gigi does not know how to do a copy).
+ -- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
+ -- for array types if the constrained status of the target type is
+ -- different from that of the expression.
+
+ if Requires_Transient_Scope (Exptyp)
+ and then
+ (not Is_Array_Type (Exptyp)
+ or else Is_Constrained (Exptyp) = Is_Constrained (R_Type)
+ or else CW_Or_Has_Controlled_Part (Utyp))
+ and then Nkind (Exp) = N_Function_Call
+ then
+ Set_By_Ref (N);
+
+ -- Remove side effects from the expression now so that other parts
+ -- of the expander do not have to reanalyze this node without this
+ -- optimization
+
+ Rewrite (Exp, Duplicate_Subexpr_No_Checks (Exp));
+
+ -- For controlled types, do the allocation on the secondary stack
+ -- manually in order to call adjust at the right time:
+
+ -- type Anon1 is access R_Type;
+ -- for Anon1'Storage_pool use ss_pool;
+ -- Anon2 : anon1 := new R_Type'(expr);
+ -- return Anon2.all;
+
+ -- We do the same for classwide types that are not potentially
+ -- controlled (by the virtue of restriction No_Finalization) because
+ -- gigi is not able to properly allocate class-wide types.
+
+ elsif CW_Or_Has_Controlled_Part (Utyp) then
+ declare
+ Loc : constant Source_Ptr := Sloc (N);
+ Acc_Typ : constant Entity_Id := Make_Temporary (Loc, 'A');
+ Alloc_Node : Node_Id;
+ Temp : Entity_Id;
+
+ begin
+ Set_Ekind (Acc_Typ, E_Access_Type);
+
+ Set_Associated_Storage_Pool (Acc_Typ, RTE (RE_SS_Pool));
+
+ -- This is an allocator for the secondary stack, and it's fine
+ -- to have Comes_From_Source set False on it, as gigi knows not
+ -- to flag it as a violation of No_Implicit_Heap_Allocations.
+
+ Alloc_Node :=
+ Make_Allocator (Loc,
+ Expression =>
+ Make_Qualified_Expression (Loc,
+ Subtype_Mark => New_Reference_To (Etype (Exp), Loc),
+ Expression => Relocate_Node (Exp)));
+
+ -- We do not want discriminant checks on the declaration,
+ -- given that it gets its value from the allocator.
+
+ Set_No_Initialization (Alloc_Node);
+
+ Temp := Make_Temporary (Loc, 'R', Alloc_Node);
+
+ Insert_List_Before_And_Analyze (N, New_List (
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Acc_Typ,
+ Type_Definition =>
+ Make_Access_To_Object_Definition (Loc,
+ Subtype_Indication => Subtype_Ind)),
+
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Temp,
+ Object_Definition => New_Reference_To (Acc_Typ, Loc),
+ Expression => Alloc_Node)));
+
+ Rewrite (Exp,
+ Make_Explicit_Dereference (Loc,
+ Prefix => New_Reference_To (Temp, Loc)));
+
+ -- Ada 2005 (AI-251): If the type of the returned object is
+ -- an interface then add an implicit type conversion to force
+ -- displacement of the "this" pointer.
+
+ if Is_Interface (R_Type) then
+ Rewrite (Exp, Convert_To (R_Type, Relocate_Node (Exp)));
+ end if;
+
+ Analyze_And_Resolve (Exp, R_Type);
+ end;
+
+ -- Otherwise use the gigi mechanism to allocate result on the
+ -- secondary stack.
+
+ else
+ Check_Restriction (No_Secondary_Stack, N);
+ Set_Storage_Pool (N, RTE (RE_SS_Pool));
+
+ -- If we are generating code for the VM do not use
+ -- SS_Allocate since everything is heap-allocated anyway.
+
+ if VM_Target = No_VM then
+ Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
+ end if;
+ end if;
+ end if;
+
+ -- Implement the rules of 6.5(8-10), which require a tag check in
+ -- the case of a limited tagged return type, and tag reassignment for
+ -- nonlimited tagged results. These actions are needed when the return
+ -- type is a specific tagged type and the result expression is a
+ -- conversion or a formal parameter, because in that case the tag of
+ -- the expression might differ from the tag of the specific result type.
+
+ if Is_Tagged_Type (Utyp)
+ and then not Is_Class_Wide_Type (Utyp)
+ and then (Nkind_In (Exp, N_Type_Conversion,
+ N_Unchecked_Type_Conversion)
+ or else (Is_Entity_Name (Exp)
+ and then Ekind (Entity (Exp)) in Formal_Kind))
+ then
+ -- When the return type is limited, perform a check that the tag of
+ -- the result is the same as the tag of the return type.
+
+ if Is_Limited_Type (R_Type) then
+ Insert_Action (Exp,
+ Make_Raise_Constraint_Error (Loc,
+ Condition =>
+ Make_Op_Ne (Loc,
+ Left_Opnd =>
+ Make_Selected_Component (Loc,
+ Prefix => Duplicate_Subexpr (Exp),
+ Selector_Name => Make_Identifier (Loc, Name_uTag)),
+ Right_Opnd =>
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Occurrence_Of (Base_Type (Utyp), Loc),
+ Attribute_Name => Name_Tag)),
+ Reason => CE_Tag_Check_Failed));
+
+ -- If the result type is a specific nonlimited tagged type, then we
+ -- have to ensure that the tag of the result is that of the result
+ -- type. This is handled by making a copy of the expression in
+ -- the case where it might have a different tag, namely when the
+ -- expression is a conversion or a formal parameter. We create a new
+ -- object of the result type and initialize it from the expression,
+ -- which will implicitly force the tag to be set appropriately.
+
+ else
+ declare
+ ExpR : constant Node_Id := Relocate_Node (Exp);
+ Result_Id : constant Entity_Id :=
+ Make_Temporary (Loc, 'R', ExpR);
+ Result_Exp : constant Node_Id :=
+ New_Reference_To (Result_Id, Loc);
+ Result_Obj : constant Node_Id :=
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Result_Id,
+ Object_Definition =>
+ New_Reference_To (R_Type, Loc),
+ Constant_Present => True,
+ Expression => ExpR);
+
+ begin
+ Set_Assignment_OK (Result_Obj);
+ Insert_Action (Exp, Result_Obj);
+
+ Rewrite (Exp, Result_Exp);
+ Analyze_And_Resolve (Exp, R_Type);
+ end;
+ end if;
+
+ -- Ada 2005 (AI-344): If the result type is class-wide, then insert
+ -- a check that the level of the return expression's underlying type
+ -- is not deeper than the level of the master enclosing the function.
+ -- Always generate the check when the type of the return expression
+ -- is class-wide, when it's a type conversion, or when it's a formal
+ -- parameter. Otherwise, suppress the check in the case where the
+ -- return expression has a specific type whose level is known not to
+ -- be statically deeper than the function's result type.
+
+ -- Note: accessibility check is skipped in the VM case, since there
+ -- does not seem to be any practical way to implement this check.
+
+ elsif Ada_Version >= Ada_2005
+ and then Tagged_Type_Expansion
+ and then Is_Class_Wide_Type (R_Type)
+ and then not Scope_Suppress (Accessibility_Check)
+ and then
+ (Is_Class_Wide_Type (Etype (Exp))
+ or else Nkind_In (Exp, N_Type_Conversion,
+ N_Unchecked_Type_Conversion)
+ or else (Is_Entity_Name (Exp)
+ and then Ekind (Entity (Exp)) in Formal_Kind)
+ or else Scope_Depth (Enclosing_Dynamic_Scope (Etype (Exp))) >
+ Scope_Depth (Enclosing_Dynamic_Scope (Scope_Id)))
+ then
+ declare
+ Tag_Node : Node_Id;
+
+ begin
+ -- Ada 2005 (AI-251): In class-wide interface objects we displace
+ -- "this" to reference the base of the object. This is required to
+ -- get access to the TSD of the object.
+
+ if Is_Class_Wide_Type (Etype (Exp))
+ and then Is_Interface (Etype (Exp))
+ and then Nkind (Exp) = N_Explicit_Dereference
+ then
+ Tag_Node :=
+ Make_Explicit_Dereference (Loc,
+ Prefix =>
+ Unchecked_Convert_To (RTE (RE_Tag_Ptr),
+ Make_Function_Call (Loc,
+ Name =>
+ New_Reference_To (RTE (RE_Base_Address), Loc),
+ Parameter_Associations => New_List (
+ Unchecked_Convert_To (RTE (RE_Address),
+ Duplicate_Subexpr (Prefix (Exp)))))));
+ else
+ Tag_Node :=
+ Make_Attribute_Reference (Loc,
+ Prefix => Duplicate_Subexpr (Exp),
+ Attribute_Name => Name_Tag);
+ end if;
+
+ Insert_Action (Exp,
+ Make_Raise_Program_Error (Loc,
+ Condition =>
+ Make_Op_Gt (Loc,
+ Left_Opnd => Build_Get_Access_Level (Loc, Tag_Node),
+ Right_Opnd =>
+ Make_Integer_Literal (Loc,
+ Scope_Depth (Enclosing_Dynamic_Scope (Scope_Id)))),
+ Reason => PE_Accessibility_Check_Failed));
+ end;
+
+ -- AI05-0073: If function has a controlling access result, check that
+ -- the tag of the return value, if it is not null, matches designated
+ -- type of return type.
+ -- The return expression is referenced twice in the code below, so
+ -- it must be made free of side effects. Given that different compilers
+ -- may evaluate these parameters in different order, both occurrences
+ -- perform a copy.
+
+ elsif Ekind (R_Type) = E_Anonymous_Access_Type
+ and then Has_Controlling_Result (Scope_Id)
+ then
+ Insert_Action (N,
+ Make_Raise_Constraint_Error (Loc,
+ Condition =>
+ Make_And_Then (Loc,
+ Left_Opnd =>
+ Make_Op_Ne (Loc,
+ Left_Opnd => Duplicate_Subexpr (Exp),
+ Right_Opnd => Make_Null (Loc)),
+
+ Right_Opnd => Make_Op_Ne (Loc,
+ Left_Opnd =>
+ Make_Selected_Component (Loc,
+ Prefix => Duplicate_Subexpr (Exp),
+ Selector_Name => Make_Identifier (Loc, Name_uTag)),
+
+ Right_Opnd =>
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Occurrence_Of (Designated_Type (R_Type), Loc),
+ Attribute_Name => Name_Tag))),
+
+ Reason => CE_Tag_Check_Failed),
+ Suppress => All_Checks);
+ end if;
+
+ -- AI05-0234: RM 6.5(21/3). Check access discriminants to
+ -- ensure that the function result does not outlive an
+ -- object designated by one of it discriminants.
+
+ if Present (Extra_Accessibility_Of_Result (Scope_Id))
+ and then Has_Unconstrained_Access_Discriminants (R_Type)
+ then
+ declare
+ Discrim_Source : Node_Id;
+
+ procedure Check_Against_Result_Level (Level : Node_Id);
+ -- Check the given accessibility level against the level
+ -- determined by the point of call. (AI05-0234).
+
+ --------------------------------
+ -- Check_Against_Result_Level --
+ --------------------------------
+
+ procedure Check_Against_Result_Level (Level : Node_Id) is
+ begin
+ Insert_Action (N,
+ Make_Raise_Program_Error (Loc,
+ Condition =>
+ Make_Op_Gt (Loc,
+ Left_Opnd => Level,
+ Right_Opnd =>
+ New_Occurrence_Of
+ (Extra_Accessibility_Of_Result (Scope_Id), Loc)),
+ Reason => PE_Accessibility_Check_Failed));
+ end Check_Against_Result_Level;
+
+ begin
+ Discrim_Source := Exp;
+ while Nkind (Discrim_Source) = N_Qualified_Expression loop
+ Discrim_Source := Expression (Discrim_Source);
+ end loop;
+
+ if Nkind (Discrim_Source) = N_Identifier
+ and then Is_Return_Object (Entity (Discrim_Source))
+ then
+ Discrim_Source := Entity (Discrim_Source);
+
+ if Is_Constrained (Etype (Discrim_Source)) then
+ Discrim_Source := Etype (Discrim_Source);
+ else
+ Discrim_Source := Expression (Parent (Discrim_Source));
+ end if;
+
+ elsif Nkind (Discrim_Source) = N_Identifier
+ and then Nkind_In (Original_Node (Discrim_Source),
+ N_Aggregate, N_Extension_Aggregate)
+ then
+ Discrim_Source := Original_Node (Discrim_Source);
+
+ elsif Nkind (Discrim_Source) = N_Explicit_Dereference and then
+ Nkind (Original_Node (Discrim_Source)) = N_Function_Call
+ then
+ Discrim_Source := Original_Node (Discrim_Source);
+ end if;
+
+ while Nkind_In (Discrim_Source, N_Qualified_Expression,
+ N_Type_Conversion,
+ N_Unchecked_Type_Conversion)
+ loop
+ Discrim_Source := Expression (Discrim_Source);
+ end loop;
+
+ case Nkind (Discrim_Source) is
+ when N_Defining_Identifier =>
+
+ pragma Assert (Is_Composite_Type (Discrim_Source)
+ and then Has_Discriminants (Discrim_Source)
+ and then Is_Constrained (Discrim_Source));
+
+ declare
+ Discrim : Entity_Id :=
+ First_Discriminant (Base_Type (R_Type));
+ Disc_Elmt : Elmt_Id :=
+ First_Elmt (Discriminant_Constraint
+ (Discrim_Source));
+ begin
+ loop
+ if Ekind (Etype (Discrim)) =
+ E_Anonymous_Access_Type
+ then
+ Check_Against_Result_Level
+ (Dynamic_Accessibility_Level (Node (Disc_Elmt)));
+ end if;
+
+ Next_Elmt (Disc_Elmt);
+ Next_Discriminant (Discrim);
+ exit when not Present (Discrim);
+ end loop;
+ end;
+
+ when N_Aggregate | N_Extension_Aggregate =>
+
+ -- Unimplemented: extension aggregate case where discrims
+ -- come from ancestor part, not extension part.
+
+ declare
+ Discrim : Entity_Id :=
+ First_Discriminant (Base_Type (R_Type));
+
+ Disc_Exp : Node_Id := Empty;
+
+ Positionals_Exhausted
+ : Boolean := not Present (Expressions
+ (Discrim_Source));
+
+ function Associated_Expr
+ (Comp_Id : Entity_Id;
+ Associations : List_Id) return Node_Id;
+
+ -- Given a component and a component associations list,
+ -- locate the expression for that component; returns
+ -- Empty if no such expression is found.
+
+ ---------------------
+ -- Associated_Expr --
+ ---------------------
+
+ function Associated_Expr
+ (Comp_Id : Entity_Id;
+ Associations : List_Id) return Node_Id
+ is
+ Assoc : Node_Id;
+ Choice : Node_Id;
+
+ begin
+ -- Simple linear search seems ok here
+
+ Assoc := First (Associations);
+ while Present (Assoc) loop
+ Choice := First (Choices (Assoc));
+ while Present (Choice) loop
+ if (Nkind (Choice) = N_Identifier
+ and then Chars (Choice) = Chars (Comp_Id))
+ or else (Nkind (Choice) = N_Others_Choice)
+ then
+ return Expression (Assoc);
+ end if;
+
+ Next (Choice);
+ end loop;
+
+ Next (Assoc);
+ end loop;
+
+ return Empty;
+ end Associated_Expr;
+
+ -- Start of processing for Expand_Simple_Function_Return
+
+ begin
+ if not Positionals_Exhausted then
+ Disc_Exp := First (Expressions (Discrim_Source));
+ end if;
+
+ loop
+ if Positionals_Exhausted then
+ Disc_Exp :=
+ Associated_Expr
+ (Discrim,
+ Component_Associations (Discrim_Source));
+ end if;
+
+ if Ekind (Etype (Discrim)) =
+ E_Anonymous_Access_Type
+ then
+ Check_Against_Result_Level
+ (Dynamic_Accessibility_Level (Disc_Exp));
+ end if;
+
+ Next_Discriminant (Discrim);
+ exit when not Present (Discrim);
+
+ if not Positionals_Exhausted then
+ Next (Disc_Exp);
+ Positionals_Exhausted := not Present (Disc_Exp);
+ end if;
+ end loop;
+ end;
+
+ when N_Function_Call =>
+
+ -- No check needed (check performed by callee)
+
+ null;
+
+ when others =>
+
+ declare
+ Level : constant Node_Id :=
+ Make_Integer_Literal (Loc,
+ Object_Access_Level (Discrim_Source));
+
+ begin
+ -- Unimplemented: check for name prefix that includes
+ -- a dereference of an access value with a dynamic
+ -- accessibility level (e.g., an access param or a
+ -- saooaaat) and use dynamic level in that case. For
+ -- example:
+ -- return Access_Param.all(Some_Index).Some_Component;
+ -- ???
+
+ Set_Etype (Level, Standard_Natural);
+ Check_Against_Result_Level (Level);
+ end;
+
+ end case;
+ end;
+ end if;
+
+ -- If we are returning an object that may not be bit-aligned, then copy
+ -- the value into a temporary first. This copy may need to expand to a
+ -- loop of component operations.
+
+ if Is_Possibly_Unaligned_Slice (Exp)
+ or else Is_Possibly_Unaligned_Object (Exp)
+ then
+ declare
+ ExpR : constant Node_Id := Relocate_Node (Exp);
+ Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', ExpR);
+ begin
+ Insert_Action (Exp,
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Tnn,
+ Constant_Present => True,
+ Object_Definition => New_Occurrence_Of (R_Type, Loc),
+ Expression => ExpR),
+ Suppress => All_Checks);
+ Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
+ end;
+ end if;
+
+ -- Generate call to postcondition checks if they are present
- Build_Protected_Subprogram_Call (N,
- Name => New_Occurrence_Of (Subp, Sloc (N)),
- Rec => Convert_Concurrent (Rec, Etype (Rec)),
- External => True);
+ if Ekind (Scope_Id) = E_Function
+ and then Has_Postconditions (Scope_Id)
+ then
+ -- We are going to reference the returned value twice in this case,
+ -- once in the call to _Postconditions, and once in the actual return
+ -- statement, but we can't have side effects happening twice, and in
+ -- any case for efficiency we don't want to do the computation twice.
+
+ -- If the returned expression is an entity name, we don't need to
+ -- worry since it is efficient and safe to reference it twice, that's
+ -- also true for literals other than string literals, and for the
+ -- case of X.all where X is an entity name.
+
+ if Is_Entity_Name (Exp)
+ or else Nkind_In (Exp, N_Character_Literal,
+ N_Integer_Literal,
+ N_Real_Literal)
+ or else (Nkind (Exp) = N_Explicit_Dereference
+ and then Is_Entity_Name (Prefix (Exp)))
+ then
+ null;
- else
- Rec := Expand_Protected_Object_Reference (N, Scop);
+ -- Otherwise we are going to need a temporary to capture the value
- if No (Rec) then
- return;
- end if;
+ else
+ declare
+ ExpR : constant Node_Id := Relocate_Node (Exp);
+ Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', ExpR);
- Build_Protected_Subprogram_Call (N,
- Name => Name (N),
- Rec => Rec,
- External => False);
+ begin
+ -- For a complex expression of an elementary type, capture
+ -- value in the temporary and use it as the reference.
+
+ if Is_Elementary_Type (R_Type) then
+ Insert_Action (Exp,
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Tnn,
+ Constant_Present => True,
+ Object_Definition => New_Occurrence_Of (R_Type, Loc),
+ Expression => ExpR),
+ Suppress => All_Checks);
+
+ Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
+
+ -- If we have something we can rename, generate a renaming of
+ -- the object and replace the expression with a reference
+
+ elsif Is_Object_Reference (Exp) then
+ Insert_Action (Exp,
+ Make_Object_Renaming_Declaration (Loc,
+ Defining_Identifier => Tnn,
+ Subtype_Mark => New_Occurrence_Of (R_Type, Loc),
+ Name => ExpR),
+ Suppress => All_Checks);
+
+ Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
+
+ -- Otherwise we have something like a string literal or an
+ -- aggregate. We could copy the value, but that would be
+ -- inefficient. Instead we make a reference to the value and
+ -- capture this reference with a renaming, the expression is
+ -- then replaced by a dereference of this renaming.
- end if;
+ else
+ -- For now, copy the value, since the code below does not
+ -- seem to work correctly ???
+
+ Insert_Action (Exp,
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Tnn,
+ Constant_Present => True,
+ Object_Definition => New_Occurrence_Of (R_Type, Loc),
+ Expression => Relocate_Node (Exp)),
+ Suppress => All_Checks);
+
+ Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
+
+ -- Insert_Action (Exp,
+ -- Make_Object_Renaming_Declaration (Loc,
+ -- Defining_Identifier => Tnn,
+ -- Access_Definition =>
+ -- Make_Access_Definition (Loc,
+ -- All_Present => True,
+ -- Subtype_Mark => New_Occurrence_Of (R_Type, Loc)),
+ -- Name =>
+ -- Make_Reference (Loc,
+ -- Prefix => Relocate_Node (Exp))),
+ -- Suppress => All_Checks);
+
+ -- Rewrite (Exp,
+ -- Make_Explicit_Dereference (Loc,
+ -- Prefix => New_Occurrence_Of (Tnn, Loc)));
+ end if;
+ end;
+ end if;
- -- If it is a function call it can appear in elaboration code and
- -- the called entity must be frozen here.
+ -- Generate call to _postconditions
- if Ekind (Subp) = E_Function then
- Freeze_Expression (Name (N));
+ Insert_Action (Exp,
+ Make_Procedure_Call_Statement (Loc,
+ Name => Make_Identifier (Loc, Name_uPostconditions),
+ Parameter_Associations => New_List (Duplicate_Subexpr (Exp))));
end if;
- -- Analyze and resolve the new call. The actuals have already been
- -- resolved, but expansion of a function call will add extra actuals
- -- if needed. Analysis of a procedure call already includes resolution.
-
- Analyze (N);
+ -- Ada 2005 (AI-251): If this return statement corresponds with an
+ -- simple return statement associated with an extended return statement
+ -- and the type of the returned object is an interface then generate an
+ -- implicit conversion to force displacement of the "this" pointer.
- if Ekind (Subp) = E_Function then
- Resolve (N, Etype (Subp));
+ if Ada_Version >= Ada_2005
+ and then Comes_From_Extended_Return_Statement (N)
+ and then Nkind (Expression (N)) = N_Identifier
+ and then Is_Interface (Utyp)
+ and then Utyp /= Underlying_Type (Exptyp)
+ then
+ Rewrite (Exp, Convert_To (Utyp, Relocate_Node (Exp)));
+ Analyze_And_Resolve (Exp);
end if;
- end Expand_Protected_Subprogram_Call;
+ end Expand_Simple_Function_Return;
--------------------------------
-- Is_Build_In_Place_Function --
-- may return objects of nonlimited descendants.
else
- return Is_Inherently_Limited_Type (Etype (E))
- and then Ada_Version >= Ada_05
+ return Is_Immutably_Limited_Type (Etype (E))
+ and then Ada_Version >= Ada_2005
and then not Debug_Flag_Dot_L;
end if;
Function_Id : Entity_Id;
begin
+ -- Return False when the expander is inactive, since awareness of
+ -- build-in-place treatment is only relevant during expansion. Note that
+ -- Is_Build_In_Place_Function, which is called as part of this function,
+ -- is also conditioned this way, but we need to check here as well to
+ -- avoid blowing up on processing protected calls when expansion is
+ -- disabled (such as with -gnatc) since those would trip over the raise
+ -- of Program_Error below.
+
+ if not Expander_Active then
+ return False;
+ end if;
+
-- Step past qualification or unchecked conversion (the latter can occur
-- in cases of calls to 'Input).
- if Nkind_In
- (Exp_Node, N_Qualified_Expression, N_Unchecked_Type_Conversion)
+ if Nkind_In (Exp_Node, N_Qualified_Expression,
+ N_Unchecked_Type_Conversion)
then
Exp_Node := Expression (N);
end if;
return False;
else
- if Is_Entity_Name (Name (Exp_Node)) then
+ -- In Alfa mode, build-in-place calls are not expanded, so that we
+ -- may end up with a call that is neither resolved to an entity, nor
+ -- an indirect call.
+
+ if Alfa_Mode then
+ return False;
+
+ elsif Is_Entity_Name (Name (Exp_Node)) then
Function_Id := Entity (Name (Exp_Node));
+ -- In the case of an explicitly dereferenced call, use the subprogram
+ -- type generated for the dereference.
+
elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
Function_Id := Etype (Name (Exp_Node));
+
+ else
+ raise Program_Error;
end if;
return Is_Build_In_Place_Function (Function_Id);
Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ))));
while Present (Iface_DT_Ptr)
- and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
+ and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
loop
pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code);
Thunk_Code,
Build_Set_Predefined_Prim_Op_Address (Loc,
- Tag_Node =>
+ Tag_Node =>
New_Reference_To (Node (Next_Elmt (Iface_DT_Ptr)), Loc),
- Position => DT_Position (Prim),
+ Position => DT_Position (Prim),
Address_Node =>
Unchecked_Convert_To (RTE (RE_Prim_Ptr),
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Unrestricted_Access))),
Build_Set_Predefined_Prim_Op_Address (Loc,
- Tag_Node =>
+ Tag_Node =>
New_Reference_To
(Node (Next_Elmt (Next_Elmt (Next_Elmt (Iface_DT_Ptr)))),
Loc),
- Position => DT_Position (Prim),
+ Position => DT_Position (Prim),
Address_Node =>
Unchecked_Convert_To (RTE (RE_Prim_Ptr),
Make_Attribute_Reference (Loc,
Next_Elmt (Iface_DT_Ptr);
pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
- -- Skip the tag of the no-thunks dispatch table
+ -- Skip tag of the no-thunks dispatch table
Next_Elmt (Iface_DT_Ptr);
pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
- -- Skip the tag of the predefined primitives no-thunks dispatch
- -- table
+ -- Skip tag of predefined primitives no-thunks dispatch table
Next_Elmt (Iface_DT_Ptr);
pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
-- Local variables
- Subp : constant Entity_Id := Entity (N);
+ Subp : constant Entity_Id := Entity (N);
-- Start of processing for Freeze_Subprogram
-- slots.
elsif Is_Imported (Subp)
- and then (Convention (Subp) = Convention_CPP
- or else Convention (Subp) = Convention_C)
+ and then (Convention (Subp) = Convention_CPP
+ or else Convention (Subp) = Convention_C)
then
null;
-- Generate code to register the primitive in non statically
-- allocated dispatch tables
- elsif not Static_Dispatch_Tables
- or else not
- Is_Library_Level_Tagged_Type (Scope (DTC_Entity (Subp)))
- then
+ elsif not Building_Static_DT (Scope (DTC_Entity (Subp))) then
+
-- When a primitive is frozen, enter its name in its dispatch
-- table slot.
Typ : constant Entity_Id := Etype (Subp);
Utyp : constant Entity_Id := Underlying_Type (Typ);
begin
- if Is_Inherently_Limited_Type (Typ) then
+ if Is_Immutably_Limited_Type (Typ) then
Set_Returns_By_Ref (Subp);
elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
Set_Returns_By_Ref (Subp);
(Allocator : Node_Id;
Function_Call : Node_Id)
is
+ Acc_Type : constant Entity_Id := Etype (Allocator);
Loc : Source_Ptr;
Func_Call : Node_Id := Function_Call;
Function_Id : Entity_Id;
Result_Subt : Entity_Id;
- Acc_Type : constant Entity_Id := Etype (Allocator);
New_Allocator : Node_Id;
Return_Obj_Access : Entity_Id;
raise Program_Error;
end if;
- Result_Subt := Etype (Function_Id);
+ Result_Subt := Available_View (Etype (Function_Id));
+
+ -- Check whether return type includes tasks. This may not have been done
+ -- previously, if the type was a limited view.
+
+ if Has_Task (Result_Subt) then
+ Build_Activation_Chain_Entity (Allocator);
+ end if;
-- When the result subtype is constrained, the return object must be
-- allocated on the caller side, and access to it is passed to the
-- called as a dispatching operation and must be treated similarly
-- to functions with unconstrained result subtypes.
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
- Add_Final_List_Actual_To_Build_In_Place_Call
+ Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, Acc_Type);
Add_Task_Actuals_To_Build_In_Place_Call
-- operations. ???
else
+ -- Case of a user-defined storage pool. Pass an allocation parameter
+ -- indicating that the function should allocate its result in the
+ -- pool, and pass the pool. Use 'Unrestricted_Access because the
+ -- pool may not be aliased.
- -- Pass an allocation parameter indicating that the function should
- -- allocate its result on the heap.
+ if VM_Target = No_VM
+ and then Present (Associated_Storage_Pool (Acc_Type))
+ then
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
+ (Func_Call, Function_Id, Alloc_Form => User_Storage_Pool,
+ Pool_Actual =>
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Reference_To
+ (Associated_Storage_Pool (Acc_Type), Loc),
+ Attribute_Name => Name_Unrestricted_Access));
+
+ -- No user-defined pool; pass an allocation parameter indicating that
+ -- the function should allocate its result on the heap.
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Alloc_Form => Global_Heap);
+ else
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
+ (Func_Call, Function_Id, Alloc_Form => Global_Heap);
+ end if;
- Add_Final_List_Actual_To_Build_In_Place_Call
+ Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, Acc_Type);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Return_Object => Empty);
end if;
+ -- If the build-in-place function call returns a controlled object,
+ -- the finalization master will require a reference to routine
+ -- Finalize_Address of the designated type. Setting this attribute
+ -- is done in the same manner to expansion of allocators.
+
+ if Needs_Finalization (Result_Subt) then
+
+ -- Controlled types with supressed finalization do not need to
+ -- associate the address of their Finalize_Address primitives with
+ -- a master since they do not need a master to begin with.
+
+ if Is_Library_Level_Entity (Acc_Type)
+ and then Finalize_Storage_Only (Result_Subt)
+ then
+ null;
+
+ -- Do not generate the call to Set_Finalize_Address in Alfa mode
+ -- because it is not necessary and results in unwanted expansion.
+ -- This expansion is also not carried out in CodePeer mode because
+ -- Finalize_Address is never built.
+
+ elsif not Alfa_Mode
+ and then not CodePeer_Mode
+ then
+ Insert_Action (Allocator,
+ Make_Set_Finalize_Address_Call (Loc,
+ Typ => Etype (Function_Id),
+ Ptr_Typ => Acc_Type));
+ end if;
+ end if;
+
-- Finally, replace the allocator node with a reference to the result
-- of the function call itself (which will effectively be an access
-- to the object created by the allocator).
Rewrite (Allocator, Make_Reference (Loc, Relocate_Node (Function_Call)));
+
+ -- Ada 2005 (AI-251): If the type of the allocator is an interface then
+ -- generate an implicit conversion to force displacement of the "this"
+ -- pointer.
+
+ if Is_Interface (Designated_Type (Acc_Type)) then
+ Rewrite (Allocator, Convert_To (Acc_Type, Relocate_Node (Allocator)));
+ end if;
+
Analyze_And_Resolve (Allocator, Acc_Type);
end Make_Build_In_Place_Call_In_Allocator;
Result_Subt := Etype (Function_Id);
+ -- If the build-in-place function returns a controlled object, then the
+ -- object needs to be finalized immediately after the context. Since
+ -- this case produces a transient scope, the servicing finalizer needs
+ -- to name the returned object. Create a temporary which is initialized
+ -- with the function call:
+ --
+ -- Temp_Id : Func_Type := BIP_Func_Call;
+ --
+ -- The initialization expression of the temporary will be rewritten by
+ -- the expander using the appropriate mechanism in Make_Build_In_Place_
+ -- Call_In_Object_Declaration.
+
+ if Needs_Finalization (Result_Subt) then
+ declare
+ Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'R');
+ Temp_Decl : Node_Id;
+
+ begin
+ -- Reset the guard on the function call since the following does
+ -- not perform actual call expansion.
+
+ Set_Is_Expanded_Build_In_Place_Call (Func_Call, False);
+
+ Temp_Decl :=
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Temp_Id,
+ Object_Definition =>
+ New_Reference_To (Result_Subt, Loc),
+ Expression =>
+ New_Copy_Tree (Function_Call));
+
+ Insert_Action (Function_Call, Temp_Decl);
+
+ Rewrite (Function_Call, New_Reference_To (Temp_Id, Loc));
+ Analyze (Function_Call);
+ end;
+
-- When the result subtype is constrained, an object of the subtype is
-- declared and an access value designating it is passed as an actual.
- if Is_Constrained (Underlying_Type (Result_Subt)) then
+ elsif Is_Constrained (Underlying_Type (Result_Subt)) then
-- Create a temporary object to hold the function result
-- called as a dispatching operation and must be treated similarly
-- to functions with unconstrained result subtypes.
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
- Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Acc_Type => Empty);
+ Add_Finalization_Master_Actual_To_Build_In_Place_Call
+ (Func_Call, Function_Id);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
-- scope is established to ensure eventual cleanup of the result.
else
-
-- Pass an allocation parameter indicating that the function should
-- allocate its result on the secondary stack.
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
- Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Acc_Type => Empty);
+ Add_Finalization_Master_Actual_To_Build_In_Place_Call
+ (Func_Call, Function_Id);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, Empty);
-
- Establish_Transient_Scope (Func_Call, Sec_Stack => True);
end if;
end Make_Build_In_Place_Call_In_Anonymous_Context;
Obj_Id : Entity_Id;
Ptr_Typ : Entity_Id;
Ptr_Typ_Decl : Node_Id;
+ New_Expr : Node_Id;
Result_Subt : Entity_Id;
Target : Node_Id;
-- controlling result, because dispatching calls to the function needs
-- to be treated effectively the same as calls to class-wide functions.
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Func_Id, Alloc_Form => Caller_Allocation);
- -- If Lhs is a selected component, then pass it along so that its prefix
- -- object will be used as the source of the finalization list.
-
- if Nkind (Lhs) = N_Selected_Component then
- Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Func_Id, Acc_Type => Empty, Sel_Comp => Lhs);
- else
- Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Func_Id, Acc_Type => Empty);
- end if;
+ Add_Finalization_Master_Actual_To_Build_In_Place_Call
+ (Func_Call, Func_Id);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Func_Id, Make_Identifier (Loc, Name_uMaster));
Ptr_Typ_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ptr_Typ,
- Type_Definition =>
+ Type_Definition =>
Make_Access_To_Object_Definition (Loc,
- All_Present => True,
+ All_Present => True,
Subtype_Indication =>
New_Reference_To (Result_Subt, Loc)));
Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
-- Finally, create an access object initialized to a reference to the
- -- function call.
+ -- function call. We know this access value is non-null, so mark the
+ -- entity accordingly to suppress junk access checks.
+
+ New_Expr := Make_Reference (Loc, Relocate_Node (Func_Call));
- Obj_Id := Make_Temporary (Loc, 'R');
+ Obj_Id := Make_Temporary (Loc, 'R', New_Expr);
Set_Etype (Obj_Id, Ptr_Typ);
+ Set_Is_Known_Non_Null (Obj_Id);
Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Obj_Id,
- Object_Definition =>
- New_Reference_To (Ptr_Typ, Loc),
- Expression =>
- Make_Reference (Loc,
- Prefix => Relocate_Node (Func_Call)));
+ Object_Definition => New_Reference_To (Ptr_Typ, Loc),
+ Expression => New_Expr);
Insert_After_And_Analyze (Ptr_Typ_Decl, Obj_Decl);
Rewrite (Assign, Make_Null_Statement (Loc));
else
return;
end if;
-
- -- When the target of the assignment is a return object of an enclosing
- -- build-in-place function and also requires finalization, the list
- -- generated for the assignment must be moved to that of the enclosing
- -- function.
-
- -- function Enclosing_BIP_Function return Ctrl_Typ is
- -- begin
- -- return (Ctrl_Parent_Part => BIP_Function with ...);
- -- end Enclosing_BIP_Function;
-
- if Is_Return_Object (Target)
- and then Needs_Finalization (Etype (Target))
- and then Needs_Finalization (Result_Subt)
- then
- declare
- Obj_List : constant Node_Id := Find_Final_List (Obj_Id);
- Encl_List : Node_Id;
- Encl_Scop : Entity_Id;
-
- begin
- Encl_Scop := Scope (Target);
-
- -- Locate the scope of the extended return statement
-
- while Present (Encl_Scop)
- and then Ekind (Encl_Scop) /= E_Return_Statement
- loop
- Encl_Scop := Scope (Encl_Scop);
- end loop;
-
- -- A return object should always be enclosed by a return statement
- -- scope at some level.
-
- pragma Assert (Present (Encl_Scop));
-
- Encl_List :=
- Make_Attribute_Reference (Loc,
- Prefix =>
- New_Reference_To (
- Finalization_Chain_Entity (Encl_Scop), Loc),
- Attribute_Name => Name_Unrestricted_Access);
-
- -- Generate a call to move final list
-
- Insert_After_And_Analyze (Obj_Decl,
- Make_Procedure_Call_Statement (Loc,
- Name =>
- New_Reference_To (RTE (RE_Move_Final_List), Loc),
- Parameter_Associations => New_List (Obj_List, Encl_List)));
- end;
- end if;
end Make_Build_In_Place_Call_In_Assignment;
----------------------------------------------------
Loc : Source_Ptr;
Obj_Def_Id : constant Entity_Id :=
Defining_Identifier (Object_Decl);
-
+ Enclosing_Func : constant Entity_Id :=
+ Enclosing_Subprogram (Obj_Def_Id);
+ Call_Deref : Node_Id;
+ Caller_Object : Node_Id;
+ Def_Id : Entity_Id;
+ Fmaster_Actual : Node_Id := Empty;
Func_Call : Node_Id := Function_Call;
Function_Id : Entity_Id;
- Result_Subt : Entity_Id;
- Caller_Object : Node_Id;
- Call_Deref : Node_Id;
- Ref_Type : Entity_Id;
+ Pool_Actual : Node_Id;
Ptr_Typ_Decl : Node_Id;
- Def_Id : Entity_Id;
- New_Expr : Node_Id;
- Enclosing_Func : Entity_Id;
Pass_Caller_Acc : Boolean := False;
+ New_Expr : Node_Id;
+ Ref_Type : Entity_Id;
+ Result_Subt : Entity_Id;
begin
-- Step past qualification or unchecked conversion (the latter can occur
Result_Subt := Etype (Function_Id);
- -- In the constrained case, add an implicit actual to the function call
- -- that provides access to the declared object. An unchecked conversion
- -- to the (specific) result type of the function is inserted to handle
- -- the case where the object is declared with a class-wide type.
-
- if Is_Constrained (Underlying_Type (Result_Subt)) then
- Caller_Object :=
- Make_Unchecked_Type_Conversion (Loc,
- Subtype_Mark => New_Reference_To (Result_Subt, Loc),
- Expression => New_Reference_To (Obj_Def_Id, Loc));
-
- -- When the function has a controlling result, an allocation-form
- -- parameter must be passed indicating that the caller is allocating
- -- the result object. This is needed because such a function can be
- -- called as a dispatching operation and must be treated similarly
- -- to functions with unconstrained result subtypes.
-
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
-
- -- If the function's result subtype is unconstrained and the object is
- -- a return object of an enclosing build-in-place function, then the
- -- implicit build-in-place parameters of the enclosing function must be
- -- passed along to the called function. (Unfortunately, this won't cover
- -- the case of extension aggregates where the ancestor part is a build-
- -- in-place unconstrained function call that should be passed along the
- -- caller's parameters. Currently those get mishandled by reassigning
- -- the result of the call to the aggregate return object, when the call
- -- result should really be directly built in place in the aggregate and
- -- not built in a temporary. ???)
-
- elsif Is_Return_Object (Defining_Identifier (Object_Decl)) then
+ -- If the the object is a return object of an enclosing build-in-place
+ -- function, then the implicit build-in-place parameters of the
+ -- enclosing function are simply passed along to the called function.
+ -- (Unfortunately, this won't cover the case of extension aggregates
+ -- where the ancestor part is a build-in-place unconstrained function
+ -- call that should be passed along the caller's parameters. Currently
+ -- those get mishandled by reassigning the result of the call to the
+ -- aggregate return object, when the call result should really be
+ -- directly built in place in the aggregate and not in a temporary. ???)
+
+ if Is_Return_Object (Defining_Identifier (Object_Decl)) then
Pass_Caller_Acc := True;
- Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
+ -- When the enclosing function has a BIP_Alloc_Form formal then we
+ -- pass it along to the callee (such as when the enclosing function
+ -- has an unconstrained or tagged result type).
- -- If the enclosing function has a constrained result type, then
- -- caller allocation will be used.
+ if Needs_BIP_Alloc_Form (Enclosing_Func) then
+ if VM_Target = No_VM and then
+ RTE_Available (RE_Root_Storage_Pool_Ptr)
+ then
+ Pool_Actual :=
+ New_Reference_To (Build_In_Place_Formal
+ (Enclosing_Func, BIP_Storage_Pool), Loc);
- if Is_Constrained (Etype (Enclosing_Func)) then
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
+ -- The build-in-place pool formal is not built on .NET/JVM
- -- Otherwise, when the enclosing function has an unconstrained result
- -- type, the BIP_Alloc_Form formal of the enclosing function must be
- -- passed along to the callee.
+ else
+ Pool_Actual := Empty;
+ end if;
- else
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call,
Function_Id,
Alloc_Form_Exp =>
New_Reference_To
(Build_In_Place_Formal (Enclosing_Func, BIP_Alloc_Form),
- Loc));
+ Loc),
+ Pool_Actual => Pool_Actual);
+
+ -- Otherwise, if enclosing function has a constrained result subtype,
+ -- then caller allocation will be used.
+
+ else
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
+ (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
+ end if;
+
+ if Needs_BIP_Finalization_Master (Enclosing_Func) then
+ Fmaster_Actual :=
+ New_Reference_To
+ (Build_In_Place_Formal
+ (Enclosing_Func, BIP_Finalization_Master), Loc);
end if;
-- Retrieve the BIPacc formal from the enclosing function and convert
(Build_In_Place_Formal (Enclosing_Func, BIP_Object_Access),
Loc));
+ -- In the constrained case, add an implicit actual to the function call
+ -- that provides access to the declared object. An unchecked conversion
+ -- to the (specific) result type of the function is inserted to handle
+ -- the case where the object is declared with a class-wide type.
+
+ elsif Is_Constrained (Underlying_Type (Result_Subt)) then
+ Caller_Object :=
+ Make_Unchecked_Type_Conversion (Loc,
+ Subtype_Mark => New_Reference_To (Result_Subt, Loc),
+ Expression => New_Reference_To (Obj_Def_Id, Loc));
+
+ -- When the function has a controlling result, an allocation-form
+ -- parameter must be passed indicating that the caller is allocating
+ -- the result object. This is needed because such a function can be
+ -- called as a dispatching operation and must be treated similarly
+ -- to functions with unconstrained result subtypes.
+
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
+ (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
+
-- In other unconstrained cases, pass an indication to do the allocation
-- on the secondary stack and set Caller_Object to Empty so that a null
-- value will be passed for the caller's object address. A transient
-- scope is established to ensure eventual cleanup of the result.
else
- Add_Alloc_Form_Actual_To_Build_In_Place_Call
- (Func_Call,
- Function_Id,
- Alloc_Form => Secondary_Stack);
+ Add_Unconstrained_Actuals_To_Build_In_Place_Call
+ (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
Caller_Object := Empty;
Establish_Transient_Scope (Object_Decl, Sec_Stack => True);
end if;
- Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Acc_Type => Empty);
+ -- Pass along any finalization master actual, which is needed in the
+ -- case where the called function initializes a return object of an
+ -- enclosing build-in-place function.
+
+ Add_Finalization_Master_Actual_To_Build_In_Place_Call
+ (Func_Call => Func_Call,
+ Func_Id => Function_Id,
+ Master_Exp => Fmaster_Actual);
if Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement
and then Has_Task (Result_Subt)
then
- Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
-
-- Here we're passing along the master that was passed in to this
-- function.
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id,
Master_Actual =>
- New_Reference_To
- (Build_In_Place_Formal (Enclosing_Func, BIP_Master), Loc));
+ New_Reference_To (Build_In_Place_Formal
+ (Enclosing_Func, BIP_Task_Master), Loc));
else
Add_Task_Actuals_To_Build_In_Place_Call
Ptr_Typ_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ref_Type,
- Type_Definition =>
+ Type_Definition =>
Make_Access_To_Object_Definition (Loc,
- All_Present => True,
+ All_Present => True,
Subtype_Indication =>
New_Reference_To (Etype (Function_Call), Loc)));
-- The access type and its accompanying object must be inserted after
-- the object declaration in the constrained case, so that the function
-- call can be passed access to the object. In the unconstrained case,
- -- the access type and object must be inserted before the object, since
- -- the object declaration is rewritten to be a renaming of a dereference
- -- of the access object.
+ -- or if the object declaration is for a return object, the access type
+ -- and object must be inserted before the object, since the object
+ -- declaration is rewritten to be a renaming of a dereference of the
+ -- access object.
- if Is_Constrained (Underlying_Type (Result_Subt)) then
+ if Is_Constrained (Underlying_Type (Result_Subt))
+ and then not Is_Return_Object (Defining_Identifier (Object_Decl))
+ then
Insert_After_And_Analyze (Object_Decl, Ptr_Typ_Decl);
else
Insert_Action (Object_Decl, Ptr_Typ_Decl);
end if;
-- Finally, create an access object initialized to a reference to the
- -- function call.
+ -- function call. We know this access value cannot be null, so mark the
+ -- entity accordingly to suppress the access check.
- New_Expr :=
- Make_Reference (Loc,
- Prefix => Relocate_Node (Func_Call));
+ New_Expr := Make_Reference (Loc, Relocate_Node (Func_Call));
Def_Id := Make_Temporary (Loc, 'R', New_Expr);
Set_Etype (Def_Id, Ref_Type);
+ Set_Is_Known_Non_Null (Def_Id);
Insert_After_And_Analyze (Ptr_Typ_Decl,
Make_Object_Declaration (Loc,
Object_Definition => New_Reference_To (Ref_Type, Loc),
Expression => New_Expr));
- if Is_Constrained (Underlying_Type (Result_Subt)) then
+ -- If the result subtype of the called function is constrained and
+ -- is not itself the return expression of an enclosing BIP function,
+ -- then mark the object as having no initialization.
+
+ if Is_Constrained (Underlying_Type (Result_Subt))
+ and then not Is_Return_Object (Defining_Identifier (Object_Decl))
+ then
Set_Expression (Object_Decl, Empty);
Set_No_Initialization (Object_Decl);
- -- In case of an unconstrained result subtype, rewrite the object
+ -- In case of an unconstrained result subtype, or if the call is the
+ -- return expression of an enclosing BIP function, rewrite the object
-- declaration as an object renaming where the renamed object is a
-- dereference of <function_Call>'reference:
--
Make_Explicit_Dereference (Loc,
Prefix => New_Reference_To (Def_Id, Loc));
+ Loc := Sloc (Object_Decl);
Rewrite (Object_Decl,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Make_Temporary (Loc, 'D'),
Set_Homonym (Renaming_Def_Id, Homonym (Obj_Def_Id));
Exchange_Entities (Renaming_Def_Id, Obj_Def_Id);
+
+ -- Preserve source indication of original declaration, so that
+ -- xref information is properly generated for the right entity.
+
+ Preserve_Comes_From_Source
+ (Object_Decl, Original_Node (Object_Decl));
+
+ Preserve_Comes_From_Source
+ (Obj_Def_Id, Original_Node (Object_Decl));
+
+ Set_Comes_From_Source (Renaming_Def_Id, False);
end;
end if;
end if;
end Make_Build_In_Place_Call_In_Object_Declaration;
+ -----------------------------------
+ -- Needs_BIP_Finalization_Master --
+ -----------------------------------
+
+ function Needs_BIP_Finalization_Master
+ (Func_Id : Entity_Id) return Boolean
+ is
+ pragma Assert (Is_Build_In_Place_Function (Func_Id));
+ Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
+ begin
+ return
+ not Restriction_Active (No_Finalization)
+ and then Needs_Finalization (Func_Typ);
+ end Needs_BIP_Finalization_Master;
+
--------------------------
- -- Needs_BIP_Final_List --
+ -- Needs_BIP_Alloc_Form --
--------------------------
- function Needs_BIP_Final_List (E : Entity_Id) return Boolean is
- pragma Assert (Is_Build_In_Place_Function (E));
- Result_Subt : constant Entity_Id := Underlying_Type (Etype (E));
+ function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean is
+ pragma Assert (Is_Build_In_Place_Function (Func_Id));
+ Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
+ begin
+ return not Is_Constrained (Func_Typ) or else Is_Tagged_Type (Func_Typ);
+ end Needs_BIP_Alloc_Form;
+
+ --------------------------------------
+ -- Needs_Result_Accessibility_Level --
+ --------------------------------------
+
+ function Needs_Result_Accessibility_Level
+ (Func_Id : Entity_Id) return Boolean
+ is
+ Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
+
+ function Has_Unconstrained_Access_Discriminant_Component
+ (Comp_Typ : Entity_Id) return Boolean;
+ -- Returns True if any component of the type has an unconstrained access
+ -- discriminant.
+
+ -----------------------------------------------------
+ -- Has_Unconstrained_Access_Discriminant_Component --
+ -----------------------------------------------------
+
+ function Has_Unconstrained_Access_Discriminant_Component
+ (Comp_Typ : Entity_Id) return Boolean
+ is
+ begin
+ if not Is_Limited_Type (Comp_Typ) then
+ return False;
+
+ -- Only limited types can have access discriminants with
+ -- defaults.
+
+ elsif Has_Unconstrained_Access_Discriminants (Comp_Typ) then
+ return True;
+
+ elsif Is_Array_Type (Comp_Typ) then
+ return Has_Unconstrained_Access_Discriminant_Component
+ (Underlying_Type (Component_Type (Comp_Typ)));
+
+ elsif Is_Record_Type (Comp_Typ) then
+ declare
+ Comp : Entity_Id;
+
+ begin
+ Comp := First_Component (Comp_Typ);
+ while Present (Comp) loop
+ if Has_Unconstrained_Access_Discriminant_Component
+ (Underlying_Type (Etype (Comp)))
+ then
+ return True;
+ end if;
+
+ Next_Component (Comp);
+ end loop;
+ end;
+ end if;
+
+ return False;
+ end Has_Unconstrained_Access_Discriminant_Component;
+
+ Feature_Disabled : constant Boolean := True;
+ -- Temporary
+
+ -- Start of processing for Needs_Result_Accessibility_Level
begin
- -- We need the BIP_Final_List if the result type needs finalization. We
- -- also need it for tagged types, even if not class-wide, because some
- -- type extension might need finalization, and all overriding functions
- -- must have the same calling conventions. However, if there is a
- -- pragma Restrictions (No_Finalization), we never need this parameter.
-
- return (Needs_Finalization (Result_Subt)
- or else Is_Tagged_Type (Underlying_Type (Result_Subt)))
- and then not Restriction_Active (No_Finalization);
- end Needs_BIP_Final_List;
+ -- False if completion unavailable (how does this happen???)
+
+ if not Present (Func_Typ) then
+ return False;
+
+ elsif Feature_Disabled then
+ return False;
+
+ -- False if not a function, also handle enum-lit renames case
+
+ elsif Func_Typ = Standard_Void_Type
+ or else Is_Scalar_Type (Func_Typ)
+ then
+ return False;
+
+ -- Handle a corner case, a cross-dialect subp renaming. For example,
+ -- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
+ -- an Ada 2005 (or earlier) unit references predefined run-time units.
+
+ elsif Present (Alias (Func_Id)) then
+
+ -- Unimplemented: a cross-dialect subp renaming which does not set
+ -- the Alias attribute (e.g., a rename of a dereference of an access
+ -- to subprogram value). ???
+
+ return Present (Extra_Accessibility_Of_Result (Alias (Func_Id)));
+
+ -- Remaining cases require Ada 2012 mode
+
+ elsif Ada_Version < Ada_2012 then
+ return False;
+
+ elsif Ekind (Func_Typ) = E_Anonymous_Access_Type
+ or else Is_Tagged_Type (Func_Typ)
+ then
+ -- In the case of, say, a null tagged record result type, the need
+ -- for this extra parameter might not be obvious. This function
+ -- returns True for all tagged types for compatibility reasons.
+ -- A function with, say, a tagged null controlling result type might
+ -- be overridden by a primitive of an extension having an access
+ -- discriminant and the overrider and overridden must have compatible
+ -- calling conventions (including implicitly declared parameters).
+ -- Similarly, values of one access-to-subprogram type might designate
+ -- both a primitive subprogram of a given type and a function
+ -- which is, for example, not a primitive subprogram of any type.
+ -- Again, this requires calling convention compatibility.
+ -- It might be possible to solve these issues by introducing
+ -- wrappers, but that is not the approach that was chosen.
+
+ return True;
+
+ elsif Has_Unconstrained_Access_Discriminants (Func_Typ) then
+ return True;
+
+ elsif Has_Unconstrained_Access_Discriminant_Component (Func_Typ) then
+ return True;
+
+ -- False for all other cases
+
+ else
+ return False;
+ end if;
+ end Needs_Result_Accessibility_Level;
end Exp_Ch6;
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