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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ C H 6 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Debug; use Debug;
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 Exp_Ch7; use Exp_Ch7;
with Exp_Ch9; use Exp_Ch9;
with Exp_Dbug; use Exp_Dbug;
with Exp_Disp; use Exp_Disp;
with Exp_Dist; use Exp_Dist;
with Exp_Intr; use Exp_Intr;
with Exp_Pakd; use Exp_Pakd;
with Exp_Prag; use Exp_Prag;
with Exp_Tss; use Exp_Tss;
with Exp_Unst; use Exp_Unst;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Inline; use Inline;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Res; use Sem_Res;
with Sem_SCIL; use Sem_SCIL;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with Validsw; use Validsw;
package body Exp_Ch6 is
-----------------------
-- Local Subprograms --
-----------------------
procedure Add_Access_Actual_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Return_Object : Node_Id;
Is_Access : Boolean := False);
-- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
-- object name given by Return_Object and add the attribute to the end of
-- the actual parameter list associated with the build-in-place function
-- call denoted by Function_Call. However, if Is_Access is True, then
-- Return_Object is already an access expression, in which case it's passed
-- along directly to the build-in-place function. Finally, if Return_Object
-- is empty, then pass a null literal as the actual.
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;
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;
Function_Id : Entity_Id;
Master_Actual : Node_Id;
Chain : Node_Id := Empty);
-- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
-- contains tasks, add two actual parameters: the master, and a pointer to
-- the caller's activation chain. Master_Actual is the actual parameter
-- 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. In most
-- contexts, the activation chain to pass is the local one, which is
-- indicated by No (Chain). However, in an allocator, the caller passes in
-- the activation Chain. 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
-- inherited private operation, in which case its DT entry is that of
-- the hidden operation, not the one it may have received earlier.
-- This must be done before emitting the code to set the corresponding
-- DT to the address of the subprogram. The actual placement of Subp in
-- the proper place in the list of primitive operations is done in
-- Declare_Inherited_Private_Subprograms, which also has to deal with
-- implicit operations. This duplication is unavoidable for now???
procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
-- This procedure is called only if the subprogram body N, whose spec
-- has the given entity Spec, contains a parameterless recursive call.
-- It attempts to generate runtime code to detect if this a case of
-- infinite recursion.
--
-- The body is scanned to determine dependencies. If the only external
-- dependencies are on a small set of scalar variables, then the values
-- of these variables are captured on entry to the subprogram, and if
-- the values are not changed for the call, we know immediately that
-- we have an infinite recursion.
procedure Expand_Actuals (N : in out 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).
--
-- For OUT and IN OUT parameters, add predicate checks after the call
-- based on the predicates of the actual type.
--
-- The parameter N is IN OUT because in some cases, the expansion code
-- rewrites the call as an expression actions with the call inside. In
-- this case N is reset to point to the inside call so that the caller
-- can continue processing of this call.
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_Non_Function_Return (N : Node_Id);
-- Expand a simple return statement found in a procedure body, entry body,
-- accept statement, or an 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;
procedure Expand_Protected_Subprogram_Call
(N : Node_Id;
Subp : Entity_Id;
Scop : Entity_Id);
-- A call to a protected subprogram within the protected object may appear
-- as a regular call. The list of actuals must be expanded to contain a
-- reference to the object itself, and the call becomes a call to the
-- corresponding protected subprogram.
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 --
----------------------------------------------
procedure Add_Access_Actual_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Return_Object : Node_Id;
Is_Access : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Obj_Address : Node_Id;
Obj_Acc_Formal : Entity_Id;
begin
-- Locate the implicit access parameter in the called function
Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
-- If no return object is provided, then pass null
if not Present (Return_Object) then
Obj_Address := Make_Null (Loc);
Set_Parent (Obj_Address, Function_Call);
-- If Return_Object is already an expression of an access type, then use
-- it directly, since it must be an access value denoting the return
-- object, and couldn't possibly be the return object itself.
elsif Is_Access then
Obj_Address := Return_Object;
Set_Parent (Obj_Address, Function_Call);
-- Apply Unrestricted_Access to caller's return object
else
Obj_Address :=
Make_Attribute_Reference (Loc,
Prefix => Return_Object,
Attribute_Name => Name_Unrestricted_Access);
Set_Parent (Return_Object, Obj_Address);
Set_Parent (Obj_Address, Function_Call);
end if;
Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_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, Obj_Acc_Formal, Obj_Address);
end Add_Access_Actual_To_Build_In_Place_Call;
------------------------------------------------------
-- Add_Unconstrained_Actuals_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;
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
-- of a constrained result subtype, since normally the caller performs
-- the allocation in that case. However this formal is still needed in
-- the case where the function has a tagged result, because generally
-- such functions can be called in a dispatching context and such calls
-- must be handled like calls to class-wide functions.
if Is_Constrained (Underlying_Type (Etype (Function_Id)))
and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
then
return;
end if;
-- Locate the implicit allocation form parameter in the called function.
-- 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. ???
Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
if Present (Alloc_Form_Exp) then
pragma Assert (Alloc_Form = Unspecified);
Alloc_Form_Actual := Alloc_Form_Exp;
else
pragma Assert (Alloc_Form /= Unspecified);
Alloc_Form_Actual :=
Make_Integer_Literal (Loc,
Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
end if;
Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_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, Alloc_Form_Formal, Alloc_Form_Actual);
-- 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,
For_Anonymous => True,
Context_Scope => Scope (Ptr_Typ),
Insertion_Node => Associated_Node_For_Itype (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_Occurrence_Of (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 --
------------------------------
procedure Add_Extra_Actual_To_Call
(Subprogram_Call : Node_Id;
Extra_Formal : Entity_Id;
Extra_Actual : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Subprogram_Call);
Param_Assoc : Node_Id;
begin
Param_Assoc :=
Make_Parameter_Association (Loc,
Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
Explicit_Actual_Parameter => Extra_Actual);
Set_Parent (Param_Assoc, Subprogram_Call);
Set_Parent (Extra_Actual, Param_Assoc);
if Present (Parameter_Associations (Subprogram_Call)) then
if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
N_Parameter_Association
then
-- Find last named actual, and append
declare
L : Node_Id;
begin
L := First_Actual (Subprogram_Call);
while Present (L) loop
if No (Next_Actual (L)) then
Set_Next_Named_Actual (Parent (L), Extra_Actual);
exit;
end if;
Next_Actual (L);
end loop;
end;
else
Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
end if;
Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
else
Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
end if;
end Add_Extra_Actual_To_Call;
---------------------------------------------
-- Add_Task_Actuals_To_Build_In_Place_Call --
---------------------------------------------
procedure Add_Task_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Master_Actual : Node_Id;
Chain : Node_Id := Empty)
is
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 (Result_Subt) then
return;
end if;
Actual := Master_Actual;
-- Use a dummy _master actual in case of No_Task_Hierarchy
if Restriction_Active (No_Task_Hierarchy) then
Actual := New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc);
-- In the case where we use the master associated with an access type,
-- the actual is an entity and requires an explicit reference.
elsif Nkind (Actual) = N_Defining_Identifier then
Actual := New_Occurrence_Of (Actual, Loc);
end if;
-- Locate the implicit master parameter in the called function
Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Task_Master);
Analyze_And_Resolve (Actual, Etype (Master_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, Master_Formal, Actual);
-- Locate the implicit activation chain parameter in the called function
Chain_Formal :=
Build_In_Place_Formal (Function_Id, BIP_Activation_Chain);
-- Create the actual which is a pointer to the current activation chain
if No (Chain) then
Chain_Actual :=
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uChain),
Attribute_Name => Name_Unrestricted_Access);
-- Allocator case; make a reference to the Chain passed in by the caller
else
Chain_Actual :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Chain, Loc),
Attribute_Name => Name_Unrestricted_Access);
end if;
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.
Add_Extra_Actual_To_Call (Function_Call, Chain_Formal, Chain_Actual);
end Add_Task_Actuals_To_Build_In_Place_Call;
-----------------------
-- BIP_Formal_Suffix --
-----------------------
function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
begin
case Kind is
when BIP_Alloc_Form =>
return "BIPalloc";
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 =>
return "BIPaccess";
end case;
end BIP_Formal_Suffix;
---------------------------
-- Build_In_Place_Formal --
---------------------------
function Build_In_Place_Formal
(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) = Formal_Name;
Next_Formal_With_Extras (Extra_Formal);
end loop;
return Extra_Formal;
end Build_In_Place_Formal;
--------------------------------
-- Check_Overriding_Operation --
--------------------------------
procedure Check_Overriding_Operation (Subp : Entity_Id) is
Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
Op_List : constant Elist_Id := Primitive_Operations (Typ);
Op_Elmt : Elmt_Id;
Prim_Op : Entity_Id;
Par_Op : Entity_Id;
begin
if Is_Derived_Type (Typ)
and then not Is_Private_Type (Typ)
and then In_Open_Scopes (Scope (Etype (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
-- Derive_Subprogram) whose Alias is a hidden subprogram with the
-- same name as Subp.
Op_Elmt := First_Elmt (Op_List);
while Present (Op_Elmt) loop
Prim_Op := Node (Op_Elmt);
Par_Op := Alias (Prim_Op);
if Present (Par_Op)
and then not Comes_From_Source (Prim_Op)
and then Chars (Prim_Op) /= Chars (Par_Op)
and then Chars (Par_Op) = Chars (Subp)
and then Is_Hidden (Par_Op)
and then Type_Conformant (Prim_Op, Subp)
then
Set_DT_Position_Value (Subp, DT_Position (Prim_Op));
end if;
Next_Elmt (Op_Elmt);
end loop;
end if;
end Check_Overriding_Operation;
-------------------------------
-- Detect_Infinite_Recursion --
-------------------------------
procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Var_List : constant Elist_Id := New_Elmt_List;
-- List of globals referenced by body of procedure
Call_List : constant Elist_Id := New_Elmt_List;
-- List of recursive calls in body of procedure
Shad_List : constant Elist_Id := New_Elmt_List;
-- List of entity id's for entities created to capture the value of
-- referenced globals on entry to the procedure.
Scop : constant Uint := Scope_Depth (Spec);
-- This is used to record the scope depth of the current procedure, so
-- that we can identify global references.
Max_Vars : constant := 4;
-- Do not test more than four global variables
Count_Vars : Natural := 0;
-- Count variables found so far
Var : Entity_Id;
Elm : Elmt_Id;
Ent : Entity_Id;
Call : Elmt_Id;
Decl : Node_Id;
Test : Node_Id;
Elm1 : Elmt_Id;
Elm2 : Elmt_Id;
Last : Node_Id;
function Process (Nod : Node_Id) return Traverse_Result;
-- Function to traverse the subprogram body (using Traverse_Func)
-------------
-- Process --
-------------
function Process (Nod : Node_Id) return Traverse_Result is
begin
-- Procedure call
if Nkind (Nod) = N_Procedure_Call_Statement then
-- Case of one of the detected recursive calls
if Is_Entity_Name (Name (Nod))
and then Has_Recursive_Call (Entity (Name (Nod)))
and then Entity (Name (Nod)) = Spec
then
Append_Elmt (Nod, Call_List);
return Skip;
-- Any other procedure call may have side effects
else
return Abandon;
end if;
-- A call to a pure function can always be ignored
elsif Nkind (Nod) = N_Function_Call
and then Is_Entity_Name (Name (Nod))
and then Is_Pure (Entity (Name (Nod)))
then
return Skip;
-- Case of an identifier reference
elsif Nkind (Nod) = N_Identifier then
Ent := Entity (Nod);
-- If no entity, then ignore the reference
-- Not clear why this can happen. To investigate, remove this
-- test and look at the crash that occurs here in 3401-004 ???
if No (Ent) then
return Skip;
-- Ignore entities with no Scope, again not clear how this
-- can happen, to investigate, look at 4108-008 ???
elsif No (Scope (Ent)) then
return Skip;
-- Ignore the reference if not to a more global object
elsif Scope_Depth (Scope (Ent)) >= Scop then
return Skip;
-- References to types, exceptions and constants are always OK
elsif Is_Type (Ent)
or else Ekind (Ent) = E_Exception
or else Ekind (Ent) = E_Constant
then
return Skip;
-- If other than a non-volatile scalar variable, we have some
-- kind of global reference (e.g. to a function) that we cannot
-- deal with so we forget the attempt.
elsif Ekind (Ent) /= E_Variable
or else not Is_Scalar_Type (Etype (Ent))
or else Treat_As_Volatile (Ent)
then
return Abandon;
-- Otherwise we have a reference to a global scalar
else
-- Loop through global entities already detected
Elm := First_Elmt (Var_List);
loop
-- If not detected before, record this new global reference
if No (Elm) then
Count_Vars := Count_Vars + 1;
if Count_Vars <= Max_Vars then
Append_Elmt (Entity (Nod), Var_List);
else
return Abandon;
end if;
exit;
-- If recorded before, ignore
elsif Node (Elm) = Entity (Nod) then
return Skip;
-- Otherwise keep looking
else
Next_Elmt (Elm);
end if;
end loop;
return Skip;
end if;
-- For all other node kinds, recursively visit syntactic children
else
return OK;
end if;
end Process;
function Traverse_Body is new Traverse_Func (Process);
-- Start of processing for Detect_Infinite_Recursion
begin
-- Do not attempt detection in No_Implicit_Conditional mode, since we
-- won't be able to generate the code to handle the recursion in any
-- case.
if Restriction_Active (No_Implicit_Conditionals) then
return;
end if;
-- Otherwise do traversal and quit if we get abandon signal
if Traverse_Body (N) = Abandon then
return;
-- We must have a call, since Has_Recursive_Call was set. If not just
-- ignore (this is only an error check, so if we have a funny situation,
-- due to bugs or errors, we do not want to bomb).
elsif Is_Empty_Elmt_List (Call_List) then
return;
end if;
-- Here is the case where we detect recursion at compile time
-- Push our current scope for analyzing the declarations and code that
-- we will insert for the checking.
Push_Scope (Spec);
-- This loop builds temporary variables for each of the referenced
-- globals, so that at the end of the loop the list Shad_List contains
-- these temporaries in one-to-one correspondence with the elements in
-- Var_List.
Last := Empty;
Elm := First_Elmt (Var_List);
while Present (Elm) loop
Var := Node (Elm);
Ent := Make_Temporary (Loc, 'S');
Append_Elmt (Ent, Shad_List);
-- Insert a declaration for this temporary at the start of the
-- declarations for the procedure. The temporaries are declared as
-- constant objects initialized to the current values of the
-- corresponding temporaries.
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
Constant_Present => True,
Expression => New_Occurrence_Of (Var, Loc));
if No (Last) then
Prepend (Decl, Declarations (N));
else
Insert_After (Last, Decl);
end if;
Last := Decl;
Analyze (Decl);
Next_Elmt (Elm);
end loop;
-- Loop through calls
Call := First_Elmt (Call_List);
while Present (Call) loop
-- Build a predicate expression of the form
-- True
-- and then global1 = temp1
-- and then global2 = temp2
-- ...
-- This predicate determines if any of the global values
-- referenced by the procedure have changed since the
-- current call, if not an infinite recursion is assured.
Test := New_Occurrence_Of (Standard_True, Loc);
Elm1 := First_Elmt (Var_List);
Elm2 := First_Elmt (Shad_List);
while Present (Elm1) loop
Test :=
Make_And_Then (Loc,
Left_Opnd => Test,
Right_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
Next_Elmt (Elm1);
Next_Elmt (Elm2);
end loop;
-- Now we replace the call with the sequence
-- if no-changes (see above) then
-- raise Storage_Error;
-- else
-- original-call
-- end if;
Rewrite (Node (Call),
Make_If_Statement (Loc,
Condition => Test,
Then_Statements => New_List (
Make_Raise_Storage_Error (Loc,
Reason => SE_Infinite_Recursion)),
Else_Statements => New_List (
Relocate_Node (Node (Call)))));
Analyze (Node (Call));
Next_Elmt (Call);
end loop;
-- Remove temporary scope stack entry used for analysis
Pop_Scope;
end Detect_Infinite_Recursion;
--------------------
-- Expand_Actuals --
--------------------
--------------------
-- Expand_Actuals --
--------------------
procedure Expand_Actuals (N : in out Node_Id; Subp : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Actual : Node_Id;
Formal : Entity_Id;
N_Node : Node_Id;
Post_Call : List_Id;
E_Actual : Entity_Id;
E_Formal : Entity_Id;
procedure Add_Call_By_Copy_Code;
-- For cases where the parameter must be passed by copy, this routine
-- generates a temporary variable into which the actual is copied and
-- then passes this as the parameter. For an OUT or IN OUT parameter,
-- an assignment is also generated to copy the result back. The call
-- also takes care of any constraint checks required for the type
-- conversion case (on both the way in and the way out).
procedure Add_Simple_Call_By_Copy_Code;
-- This is similar to the above, but is used in cases where we know
-- that all that is needed is to simply create a temporary and copy
-- the value in and out of the temporary.
procedure Check_Fortran_Logical;
-- A value of type Logical that is passed through a formal parameter
-- must be normalized because .TRUE. usually does not have the same
-- representation as True. We assume that .FALSE. = False = 0.
-- What about functions that return a logical type ???
function Is_Legal_Copy return Boolean;
-- Check that an actual can be copied before generating the temporary
-- to be used in the call. If the actual is of a by_reference type then
-- the program is illegal (this can only happen in the presence of
-- rep. clauses that force an incorrect alignment). If the formal is
-- a by_reference parameter imposed by a DEC pragma, emit a warning to
-- the effect that this might lead to unaligned arguments.
function Make_Var (Actual : Node_Id) return Entity_Id;
-- Returns an entity that refers to the given actual parameter, Actual
-- (not including any type conversion). If Actual is an entity name,
-- then this entity is returned unchanged, otherwise a renaming is
-- created to provide an entity for the actual.
procedure Reset_Packed_Prefix;
-- The expansion of a packed array component reference is delayed in
-- the context of a call. Now we need to complete the expansion, so we
-- unmark the analyzed bits in all prefixes.
---------------------------
-- Add_Call_By_Copy_Code --
---------------------------
procedure Add_Call_By_Copy_Code is
Expr : Node_Id;
Init : Node_Id;
Temp : Entity_Id;
Indic : Node_Id;
Var : Entity_Id;
F_Typ : constant Entity_Id := Etype (Formal);
V_Typ : Entity_Id;
Crep : Boolean;
begin
if not Is_Legal_Copy then
return;
end if;
Temp := Make_Temporary (Loc, 'T', Actual);
-- Use formal type for temp, unless formal type is an unconstrained
-- array, in which case we don't have to worry about bounds checks,
-- and we use the actual type, since that has appropriate bounds.
if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
Indic := New_Occurrence_Of (Etype (Actual), Loc);
else
Indic := New_Occurrence_Of (Etype (Formal), Loc);
end if;
if Nkind (Actual) = N_Type_Conversion then
V_Typ := Etype (Expression (Actual));
-- If the formal is an (in-)out parameter, capture the name
-- of the variable in order to build the post-call assignment.
Var := Make_Var (Expression (Actual));
Crep := not Same_Representation
(F_Typ, Etype (Expression (Actual)));
else
V_Typ := Etype (Actual);
Var := Make_Var (Actual);
Crep := False;
end if;
-- Setup initialization for case of in out parameter, or an out
-- parameter where the formal is an unconstrained array (in the
-- latter case, we have to pass in an object with bounds).
-- If this is an out parameter, the initial copy is wasteful, so as
-- an optimization for the one-dimensional case we extract the
-- bounds of the actual and build an uninitialized temporary of the
-- right size.
if Ekind (Formal) = E_In_Out_Parameter
or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
then
if Nkind (Actual) = N_Type_Conversion then
if Conversion_OK (Actual) then
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
else
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
end if;
elsif Ekind (Formal) = E_Out_Parameter
and then Is_Array_Type (F_Typ)
and then Number_Dimensions (F_Typ) = 1
and then not Has_Non_Null_Base_Init_Proc (F_Typ)
then
-- Actual is a one-dimensional array or slice, and the type
-- requires no initialization. Create a temporary of the
-- right size, but do not copy actual into it (optimization).
Init := Empty;
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (F_Typ, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Range (Loc,
Low_Bound =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Var, Loc),
Attribute_Name => Name_First),
High_Bound =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Var, Loc),
Attribute_Name => Name_Last)))));
else
Init := New_Occurrence_Of (Var, Loc);
end if;
-- An initialization is created for packed conversions as
-- actuals for out parameters to enable Make_Object_Declaration
-- to determine the proper subtype for N_Node. Note that this
-- is wasteful because the extra copying on the call side is
-- not required for such out parameters. ???
elsif Ekind (Formal) = E_Out_Parameter
and then Nkind (Actual) = N_Type_Conversion
and then (Is_Bit_Packed_Array (F_Typ)
or else
Is_Bit_Packed_Array (Etype (Expression (Actual))))
then
if Conversion_OK (Actual) then
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
else
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
end if;
elsif Ekind (Formal) = E_In_Parameter then
-- Handle the case in which the actual is a type conversion
if Nkind (Actual) = N_Type_Conversion then
if Conversion_OK (Actual) then
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
else
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
end if;
else
Init := New_Occurrence_Of (Var, Loc);
end if;
else
Init := Empty;
end if;
N_Node :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => Indic,
Expression => Init);
Set_Assignment_OK (N_Node);
Insert_Action (N, N_Node);
-- Now, normally the deal here is that we use the defining
-- identifier created by that object declaration. There is
-- one exception to this. In the change of representation case
-- the above declaration will end up looking like:
-- temp : type := identifier;
-- And in this case we might as well use the identifier directly
-- and eliminate the temporary. Note that the analysis of the
-- declaration was not a waste of time in that case, since it is
-- what generated the necessary change of representation code. If
-- the change of representation introduced additional code, as in
-- a fixed-integer conversion, the expression is not an identifier
-- and must be kept.
if Crep
and then Present (Expression (N_Node))
and then Is_Entity_Name (Expression (N_Node))
then
Temp := Entity (Expression (N_Node));
Rewrite (N_Node, Make_Null_Statement (Loc));
end if;
-- For IN parameter, all we do is to replace the actual
if Ekind (Formal) = E_In_Parameter then
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
Analyze (Actual);
-- Processing for OUT or IN OUT parameter
else
-- Kill current value indications for the temporary variable we
-- created, since we just passed it as an OUT parameter.
Kill_Current_Values (Temp);
Set_Is_Known_Valid (Temp, False);
-- If type conversion, use reverse conversion on exit
if Nkind (Actual) = N_Type_Conversion then
if Conversion_OK (Actual) then
Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
else
Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
end if;
else
Expr := New_Occurrence_Of (Temp, Loc);
end if;
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
Analyze (Actual);
-- If the actual is a conversion of a packed reference, it may
-- already have been expanded by Remove_Side_Effects, and the
-- resulting variable is a temporary which does not designate
-- the proper out-parameter, which may not be addressable. In
-- that case, generate an assignment to the original expression
-- (before expansion of the packed reference) so that the proper
-- expansion of assignment to a packed component can take place.
declare
Obj : Node_Id;
Lhs : Node_Id;
begin
if Is_Renaming_Of_Object (Var)
and then Nkind (Renamed_Object (Var)) = N_Selected_Component
and then Is_Entity_Name (Prefix (Renamed_Object (Var)))
and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
= N_Indexed_Component
and then
Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
then
Obj := Renamed_Object (Var);
Lhs :=
Make_Selected_Component (Loc,
Prefix =>
New_Copy_Tree (Original_Node (Prefix (Obj))),
Selector_Name => New_Copy (Selector_Name (Obj)));
Reset_Analyzed_Flags (Lhs);
else
Lhs := New_Occurrence_Of (Var, Loc);
end if;
Set_Assignment_OK (Lhs);
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;
----------------------------------
-- Add_Simple_Call_By_Copy_Code --
----------------------------------
procedure Add_Simple_Call_By_Copy_Code is
Temp : Entity_Id;
Decl : Node_Id;
Incod : Node_Id;
Outcod : Node_Id;
Lhs : Node_Id;
Rhs : Node_Id;
Indic : Node_Id;
F_Typ : constant Entity_Id := Etype (Formal);
begin
if not Is_Legal_Copy then
return;
end if;
-- Use formal type for temp, unless formal type is an unconstrained
-- array, in which case we don't have to worry about bounds checks,
-- and we use the actual type, since that has appropriate bounds.
if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
Indic := New_Occurrence_Of (Etype (Actual), Loc);
else
Indic := New_Occurrence_Of (Etype (Formal), Loc);
end if;
-- Prepare to generate code
Reset_Packed_Prefix;
Temp := Make_Temporary (Loc, 'T', Actual);
Incod := Relocate_Node (Actual);
Outcod := New_Copy_Tree (Incod);
-- Generate declaration of temporary variable, initializing it
-- with the input parameter unless we have an OUT formal or
-- this is an initialization call.
-- If the formal is an out parameter with discriminants, the
-- discriminants must be captured even if the rest of the object
-- is in principle uninitialized, because the discriminants may
-- be read by the called subprogram.
if Ekind (Formal) = E_Out_Parameter then
Incod := Empty;
if Has_Discriminants (Etype (Formal)) then
Indic := New_Occurrence_Of (Etype (Actual), Loc);
end if;
elsif Inside_Init_Proc then
-- Could use a comment here to match comment below ???
if Nkind (Actual) /= N_Selected_Component
or else
not Has_Discriminant_Dependent_Constraint
(Entity (Selector_Name (Actual)))
then
Incod := Empty;
-- Otherwise, keep the component in order to generate the proper
-- actual subtype, that depends on enclosing discriminants.
else
null;
end if;
end if;
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => Indic,
Expression => Incod);
if Inside_Init_Proc
and then No (Incod)
then
-- If the call is to initialize a component of a composite type,
-- and the component does not depend on discriminants, use the
-- actual type of the component. This is required in case the
-- component is constrained, because in general the formal of the
-- initialization procedure will be unconstrained. Note that if
-- the component being initialized is constrained by an enclosing
-- discriminant, the presence of the initialization in the
-- declaration will generate an expression for the actual subtype.
Set_No_Initialization (Decl);
Set_Object_Definition (Decl,
New_Occurrence_Of (Etype (Actual), Loc));
end if;
Insert_Action (N, Decl);
-- The actual is simply a reference to the temporary
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
-- Generate copy out if OUT or IN OUT parameter
if Ekind (Formal) /= E_In_Parameter then
Lhs := Outcod;
Rhs := New_Occurrence_Of (Temp, Loc);
-- Deal with conversion
if Nkind (Lhs) = N_Type_Conversion then
Lhs := Expression (Lhs);
Rhs := Convert_To (Etype (Actual), Rhs);
end if;
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Rhs));
Set_Assignment_OK (Name (Last (Post_Call)));
end if;
end Add_Simple_Call_By_Copy_Code;
---------------------------
-- Check_Fortran_Logical --
---------------------------
procedure Check_Fortran_Logical is
Logical : constant Entity_Id := Etype (Formal);
Var : Entity_Id;
-- Note: this is very incomplete, e.g. it does not handle arrays
-- of logical values. This is really not the right approach at all???)
begin
if Convention (Subp) = Convention_Fortran
and then Root_Type (Etype (Formal)) = Standard_Boolean
and then Ekind (Formal) /= E_In_Parameter
then
Var := Make_Var (Actual);
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Var, Loc),
Expression =>
Unchecked_Convert_To (
Logical,
Make_Op_Ne (Loc,
Left_Opnd => New_Occurrence_Of (Var, Loc),
Right_Opnd =>
Unchecked_Convert_To (
Logical,
New_Occurrence_Of (Standard_False, Loc))))));
end if;
end Check_Fortran_Logical;
-------------------
-- Is_Legal_Copy --
-------------------
function Is_Legal_Copy return Boolean is
begin
-- An attempt to copy a value of such a type can only occur if
-- representation clauses give the actual a misaligned address.
if Is_By_Reference_Type (Etype (Formal)) then
-- If the front-end does not perform full type layout, the actual
-- may in fact be properly aligned but there is not enough front-
-- end information to determine this. In that case gigi will emit
-- an error if a copy is not legal, or generate the proper code.
-- For other backends we report the error now.
-- Seems wrong to be issuing an error in the expander, since it
-- will be missed in -gnatc mode ???
if Frontend_Layout_On_Target then
Error_Msg_N
("misaligned actual cannot be passed by reference", Actual);
end if;
return False;
-- For users of Starlet, we assume that the specification of by-
-- reference mechanism is mandatory. This may lead to unaligned
-- objects but at least for DEC legacy code it is known to work.
-- The warning will alert users of this code that a problem may
-- be lurking.
elsif Mechanism (Formal) = By_Reference
and then Is_Valued_Procedure (Scope (Formal))
then
Error_Msg_N
("by_reference actual may be misaligned??", Actual);
return False;
else
return True;
end if;
end Is_Legal_Copy;
--------------
-- Make_Var --
--------------
function Make_Var (Actual : Node_Id) return Entity_Id is
Var : Entity_Id;
begin
if Is_Entity_Name (Actual) then
return Entity (Actual);
else
Var := Make_Temporary (Loc, 'T', Actual);
N_Node :=
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Var,
Subtype_Mark =>
New_Occurrence_Of (Etype (Actual), Loc),
Name => Relocate_Node (Actual));
Insert_Action (N, N_Node);
return Var;
end if;
end Make_Var;
-------------------------
-- Reset_Packed_Prefix --
-------------------------
procedure Reset_Packed_Prefix is
Pfx : Node_Id := Actual;
begin
loop
Set_Analyzed (Pfx, False);
exit when
not Nkind_In (Pfx, N_Selected_Component, N_Indexed_Component);
Pfx := Prefix (Pfx);
end loop;
end Reset_Packed_Prefix;
-- Start of processing for Expand_Actuals
begin
Post_Call := New_List;
Formal := First_Formal (Subp);
Actual := First_Actual (N);
while Present (Formal) loop
E_Formal := Etype (Formal);
E_Actual := Etype (Actual);
if Is_Scalar_Type (E_Formal)
or else Nkind (Actual) = N_Slice
then
Check_Fortran_Logical;
-- RM 6.4.1 (11)
elsif Ekind (Formal) /= E_Out_Parameter then
-- The unusual case of the current instance of a protected type
-- requires special handling. This can only occur in the context
-- of a call within the body of a protected operation.
if Is_Entity_Name (Actual)
and then Ekind (Entity (Actual)) = E_Protected_Type
and then In_Open_Scopes (Entity (Actual))
then
if Scope (Subp) /= Entity (Actual) then
Error_Msg_N
("operation outside protected type may not "
& "call back its protected operations??", Actual);
end if;
Rewrite (Actual,
Expand_Protected_Object_Reference (N, Entity (Actual)));
end if;
-- Ada 2005 (AI-318-02): If the actual parameter is a call to a
-- build-in-place function, then a temporary return object needs
-- to be created and access to it must be passed to the function.
-- Currently we limit such functions to those with inherently
-- limited result subtypes, but eventually we plan to expand the
-- functions that are treated as build-in-place to include other
-- composite result types.
if Is_Build_In_Place_Function_Call (Actual) then
Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
end if;
Apply_Constraint_Check (Actual, E_Formal);
-- Out parameter case. No constraint checks on access type
-- RM 6.4.1 (13)
elsif Is_Access_Type (E_Formal) then
null;
-- RM 6.4.1 (14)
elsif Has_Discriminants (Base_Type (E_Formal))
or else Has_Non_Null_Base_Init_Proc (E_Formal)
then
Apply_Constraint_Check (Actual, E_Formal);
-- RM 6.4.1 (15)
else
Apply_Constraint_Check (Actual, Base_Type (E_Formal));
end if;
-- Processing for IN-OUT and OUT parameters
if Ekind (Formal) /= E_In_Parameter then
-- For type conversions of arrays, apply length/range checks
if Is_Array_Type (E_Formal)
and then Nkind (Actual) = N_Type_Conversion
then
if Is_Constrained (E_Formal) then
Apply_Length_Check (Expression (Actual), E_Formal);
else
Apply_Range_Check (Expression (Actual), E_Formal);
end if;
end if;
-- If argument is a type conversion for a type that is passed
-- by copy, then we must pass the parameter by copy.
if Nkind (Actual) = N_Type_Conversion
and then
(Is_Numeric_Type (E_Formal)
or else Is_Access_Type (E_Formal)
or else Is_Enumeration_Type (E_Formal)
or else Is_Bit_Packed_Array (Etype (Formal))
or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
-- Also pass by copy if change of representation
or else not Same_Representation
(Etype (Formal),
Etype (Expression (Actual))))
then
Add_Call_By_Copy_Code;
-- References to components of bit packed arrays are expanded
-- at this point, rather than at the point of analysis of the
-- actuals, to handle the expansion of the assignment to
-- [in] out parameters.
elsif Is_Ref_To_Bit_Packed_Array (Actual) then
Add_Simple_Call_By_Copy_Code;
-- If a non-scalar actual is possibly bit-aligned, we need a copy
-- because the back-end cannot cope with such objects. In other
-- cases where alignment forces a copy, the back-end generates
-- it properly. It should not be generated unconditionally in the
-- front-end because it does not know precisely the alignment
-- requirements of the target, and makes too conservative an
-- estimate, leading to superfluous copies or spurious errors
-- on by-reference parameters.
elsif Nkind (Actual) = N_Selected_Component
and then
Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
and then not Represented_As_Scalar (Etype (Formal))
then
Add_Simple_Call_By_Copy_Code;
-- References to slices of bit packed arrays are expanded
elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
Add_Call_By_Copy_Code;
-- References to possibly unaligned slices of arrays are expanded
elsif Is_Possibly_Unaligned_Slice (Actual) then
Add_Call_By_Copy_Code;
-- Deal with access types where the actual subtype and the
-- formal subtype are not the same, requiring a check.
-- It is necessary to exclude tagged types because of "downward
-- conversion" errors.
elsif Is_Access_Type (E_Formal)
and then not Same_Type (E_Formal, E_Actual)
and then not Is_Tagged_Type (Designated_Type (E_Formal))
then
Add_Call_By_Copy_Code;
-- If the actual is not a scalar and is marked for volatile
-- treatment, whereas the formal is not volatile, then pass
-- by copy unless it is a by-reference type.
-- Note: we use Is_Volatile here rather than Treat_As_Volatile,
-- because this is the enforcement of a language rule that applies
-- only to "real" volatile variables, not e.g. to the address
-- clause overlay case.
elsif Is_Entity_Name (Actual)
and then Is_Volatile (Entity (Actual))
and then not Is_By_Reference_Type (E_Actual)
and then not Is_Scalar_Type (Etype (Entity (Actual)))
and then not Is_Volatile (E_Formal)
then
Add_Call_By_Copy_Code;
elsif Nkind (Actual) = N_Indexed_Component
and then Is_Entity_Name (Prefix (Actual))
and then Has_Volatile_Components (Entity (Prefix (Actual)))
then
Add_Call_By_Copy_Code;
-- Add call-by-copy code for the case of scalar out parameters
-- when it is not known at compile time that the subtype of the
-- formal is a subrange of the subtype of the actual (or vice
-- versa for in out parameters), in order to get range checks
-- on such actuals. (Maybe this case should be handled earlier
-- in the if statement???)
elsif Is_Scalar_Type (E_Formal)
and then
(not In_Subrange_Of (E_Formal, E_Actual)
or else
(Ekind (Formal) = E_In_Out_Parameter
and then not In_Subrange_Of (E_Actual, E_Formal)))
then
-- Perhaps the setting back to False should be done within
-- Add_Call_By_Copy_Code, since it could get set on other
-- cases occurring above???
if Do_Range_Check (Actual) then
Set_Do_Range_Check (Actual, False);
end if;
Add_Call_By_Copy_Code;
end if;
-- RM 3.2.4 (23/3): A predicate is checked on in-out and out
-- by-reference parameters on exit from the call. If the actual
-- is a derived type and the operation is inherited, the body
-- of the operation will not contain a call to the predicate
-- function, so it must be done explicitly after the call. Ditto
-- if the actual is an entity of a predicated subtype.
-- The rule refers to by-reference types, but a check is needed
-- for by-copy types as well. That check is subsumed by the rule
-- for subtype conversion on assignment, but we can generate the
-- required check now.
-- Note also that Subp may be either a subprogram entity for
-- direct calls, or a type entity for indirect calls, which must
-- be handled separately because the name does not denote an
-- overloadable entity.
By_Ref_Predicate_Check : declare
Aund : constant Entity_Id := Underlying_Type (E_Actual);
Atyp : Entity_Id;
function Is_Public_Subp return Boolean;
-- Check whether the subprogram being called is a visible
-- operation of the type of the actual. Used to determine
-- whether an invariant check must be generated on the
-- caller side.
---------------------
-- Is_Public_Subp --
---------------------
function Is_Public_Subp return Boolean is
Pack : constant Entity_Id := Scope (Subp);
Subp_Decl : Node_Id;
begin
if not Is_Subprogram (Subp) then
return False;
-- The operation may be inherited, or a primitive of the
-- root type.
elsif
Nkind_In (Parent (Subp), N_Private_Extension_Declaration,
N_Full_Type_Declaration)
then
Subp_Decl := Parent (Subp);
else
Subp_Decl := Unit_Declaration_Node (Subp);
end if;
return Ekind (Pack) = E_Package
and then
List_Containing (Subp_Decl) =
Visible_Declarations
(Specification (Unit_Declaration_Node (Pack)));
end Is_Public_Subp;
-- Start of processing for By_Ref_Predicate_Check
begin
if No (Aund) then
Atyp := E_Actual;
else
Atyp := Aund;
end if;
if Has_Predicates (Atyp)
and then Present (Predicate_Function (Atyp))
-- Skip predicate checks for special cases
and then Predicate_Tests_On_Arguments (Subp)
then
Append_To (Post_Call,
Make_Predicate_Check (Atyp, Actual));
end if;
-- We generated caller-side invariant checks in two cases:
-- a) when calling an inherited operation, where there is an
-- implicit view conversion of the actual to the parent type.
-- b) When the conversion is explicit
-- We treat these cases separately because the required
-- conversion for a) is added later when expanding the call.
if Has_Invariants (Etype (Actual))
and then
Nkind (Parent (Subp)) = N_Private_Extension_Declaration
then
if Comes_From_Source (N) and then Is_Public_Subp then
Append_To (Post_Call, Make_Invariant_Call (Actual));
end if;
elsif Nkind (Actual) = N_Type_Conversion
and then Has_Invariants (Etype (Expression (Actual)))
then
if Comes_From_Source (N) and then Is_Public_Subp then
Append_To (Post_Call,
Make_Invariant_Call (Expression (Actual)));
end if;
end if;
end By_Ref_Predicate_Check;
-- Processing for IN parameters
else
-- For IN parameters is in the packed array case, we expand an
-- indexed component (the circuit in Exp_Ch4 deliberately left
-- indexed components appearing as actuals untouched, so that
-- the special processing above for the OUT and IN OUT cases
-- could be performed. We could make the test in Exp_Ch4 more
-- complex and have it detect the parameter mode, but it is
-- easier simply to handle all cases here.)
if Nkind (Actual) = N_Indexed_Component
and then Is_Packed (Etype (Prefix (Actual)))
then
Reset_Packed_Prefix;
Expand_Packed_Element_Reference (Actual);
-- If we have a reference to a bit packed array, we copy it, since
-- the actual must be byte aligned.
-- Is this really necessary in all cases???
elsif Is_Ref_To_Bit_Packed_Array (Actual) then
Add_Simple_Call_By_Copy_Code;
-- If a non-scalar actual is possibly unaligned, we need a copy
elsif Is_Possibly_Unaligned_Object (Actual)
and then not Represented_As_Scalar (Etype (Formal))
then
Add_Simple_Call_By_Copy_Code;
-- Similarly, we have to expand slices of packed arrays here
-- because the result must be byte aligned.
elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
Add_Call_By_Copy_Code;
-- Only processing remaining is to pass by copy if this is a
-- reference to a possibly unaligned slice, since the caller
-- expects an appropriately aligned argument.
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_Occurrence_Of (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;
Next_Formal (Formal);
Next_Actual (Actual);
end loop;
-- Find right place to put post call stuff if it is present
if not Is_Empty_List (Post_Call) then
-- Cases where the call is not a member of a statement list
if not Is_List_Member (N) then
-- 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.
if Ada_Version >= Ada_2012
and then Nkind (N) = N_Function_Call
then
-- We used to just do handle this by climbing up parents to
-- a non-statement/declaration and then simply making a call
-- to Insert_Actions_After (P, Post_Call), but that doesn't
-- work. If we are in the middle of an expression, e.g. the
-- condition of an IF, this call would insert after the IF
-- statement, which is much too late to be doing the write
-- back. For example:
-- if Clobber (X) then
-- Put_Line (X'Img);
-- else
-- goto Junk
-- end if;
-- Now assume Clobber changes X, if we put the write back
-- after the IF, the Put_Line gets the wrong value and the
-- goto causes the write back to be skipped completely.
-- To deal with this, we replace the call by
-- do
-- Tnnn : function-result-type renames function-call;
-- Post_Call actions
-- in
-- Tnnn;
-- end;
-- Note: this won't do in Modify_Tree_For_C mode, but we
-- will deal with that later (it will require creating a
-- declaration for Temp, using Insert_Declaration) ???
declare
Tnnn : constant Entity_Id := Make_Temporary (Loc, 'T');
FRTyp : constant Entity_Id := Etype (N);
Name : constant Node_Id := Relocate_Node (N);
begin
Prepend_To (Post_Call,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Tnnn,
Subtype_Mark => New_Occurrence_Of (FRTyp, Loc),
Name => Name));
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => Post_Call,
Expression => New_Occurrence_Of (Tnnn, Loc)));
-- We don't want to just blindly call Analyze_And_Resolve
-- because that would cause unwanted recursion on the call.
-- So for a moment set the call as analyzed to prevent that
-- recursion, and get the rest analyzed properly, then reset
-- the analyzed flag, so our caller can continue.
Set_Analyzed (Name, True);
Analyze_And_Resolve (N, FRTyp);
Set_Analyzed (Name, False);
-- Reset calling argument to point to function call inside
-- the expression with actions so the caller can continue
-- to process the call.
N := Name;
end;
-- 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.
else
declare
P : Node_Id;
begin
P := Parent (N);
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;
return;
end;
end if;
-- Otherwise, normal case where N is in a statement sequence,
-- just put the post-call stuff after the call statement.
else
Insert_Actions_After (N, Post_Call);
return;
end if;
end if;
-- The call node itself is re-analyzed in Expand_Call
end Expand_Actuals;
-----------------
-- Expand_Call --
-----------------
-- This procedure handles expansion of function calls and procedure call
-- statements (i.e. it serves as the body for Expand_N_Function_Call and
-- Expand_N_Procedure_Call_Statement). Processing for calls includes:
-- Replace call to Raise_Exception by Raise_Exception_Always if possible
-- Provide values of actuals for all formals in Extra_Formals list
-- Replace "call" to enumeration literal function by literal itself
-- Rewrite call to predefined operator as operator
-- Replace actuals to in-out parameters that are numeric conversions,
-- with explicit assignment to temporaries before and after the call.
-- Note that the list of actuals has been filled with default expressions
-- during semantic analysis of the call. Only the extra actuals required
-- for the 'Constrained attribute and for accessibility checks are added
-- at this point.
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;
procedure Add_Actual_Parameter (Insert_Param : Node_Id);
-- Adds one entry to the end of the actual parameter list. Used for
-- default parameters and for extra actuals (for Extra_Formals). The
-- argument is an N_Parameter_Association node.
procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
-- Adds an extra actual to the list of extra actuals. Expr is the
-- expression for the value of the actual, EF is the entity for the
-- extra formal.
function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
-- Within an instance, a type derived from an untagged formal derived
-- type inherits from the original parent, not from the actual. The
-- current derivation mechanism has the derived type inherit from the
-- actual, which is only correct outside of the instance. If the
-- subprogram is inherited, we test for this particular case through a
-- convoluted tree traversal before setting the proper subprogram to be
-- called.
function In_Unfrozen_Instance (E : Entity_Id) return Boolean;
-- Return true if E comes from an instance that is not yet frozen
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 --
--------------------------
procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
Actual_Expr : constant Node_Id :=
Explicit_Actual_Parameter (Insert_Param);
begin
-- Case of insertion is first named actual
if No (Prev) or else
Nkind (Parent (Prev)) /= N_Parameter_Association
then
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 (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;
-- Case of insertion is not first named actual
else
Set_Next_Named_Actual
(Insert_Param, Next_Named_Actual (Parent (Prev)));
Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
Append (Insert_Param, Parameter_Associations (Call_Node));
end if;
Prev := Actual_Expr;
end Add_Actual_Parameter;
----------------------
-- Add_Extra_Actual --
----------------------
procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Expr);
begin
if Extra_Actuals = No_List then
Extra_Actuals := New_List;
Set_Parent (Extra_Actuals, Call_Node);
end if;
Append_To (Extra_Actuals,
Make_Parameter_Association (Loc,
Selector_Name => New_Occurrence_Of (EF, Loc),
Explicit_Actual_Parameter => Expr));
Analyze_And_Resolve (Expr, Etype (EF));
if Nkind (Call_Node) = N_Function_Call then
Set_Is_Accessibility_Actual (Parent (Expr));
end if;
end Add_Extra_Actual;
---------------------------
-- Inherited_From_Formal --
---------------------------
function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
Par : Entity_Id;
Gen_Par : Entity_Id;
Gen_Prim : Elist_Id;
Elmt : Elmt_Id;
Indic : Node_Id;
begin
-- If the operation is inherited, it is attached to the corresponding
-- type derivation. If the parent in the derivation is a generic
-- actual, it is a subtype of the actual, and we have to recover the
-- original derived type declaration to find the proper parent.
if Nkind (Parent (S)) /= N_Full_Type_Declaration
or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
N_Derived_Type_Definition
or else not In_Instance
then
return Empty;
else
Indic :=
Subtype_Indication
(Type_Definition (Original_Node (Parent (S))));
if Nkind (Indic) = N_Subtype_Indication then
Par := Entity (Subtype_Mark (Indic));
else
Par := Entity (Indic);
end if;
end if;
if not Is_Generic_Actual_Type (Par)
or else Is_Tagged_Type (Par)
or else Nkind (Parent (Par)) /= N_Subtype_Declaration
or else not In_Open_Scopes (Scope (Par))
then
return Empty;
else
Gen_Par := Generic_Parent_Type (Parent (Par));
end if;
-- If the actual has no generic parent type, the formal is not
-- a formal derived type, so nothing to inherit.
if No (Gen_Par) then
return Empty;
end if;
-- If the generic parent type is still the generic type, this is a
-- private formal, not a derived formal, and there are no operations
-- inherited from the formal.
if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
return Empty;
end if;
Gen_Prim := Collect_Primitive_Operations (Gen_Par);
Elmt := First_Elmt (Gen_Prim);
while Present (Elmt) loop
if Chars (Node (Elmt)) = Chars (S) then
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (S);
F2 := First_Formal (Node (Elmt));
while Present (F1)
and then Present (F2)
loop
if Etype (F1) = Etype (F2)
or else Etype (F2) = Gen_Par
then
Next_Formal (F1);
Next_Formal (F2);
else
Next_Elmt (Elmt);
exit; -- not the right subprogram
end if;
return Node (Elmt);
end loop;
end;
else
Next_Elmt (Elmt);
end if;
end loop;
raise Program_Error;
end Inherited_From_Formal;
--------------------------
-- In_Unfrozen_Instance --
--------------------------
function In_Unfrozen_Instance (E : Entity_Id) return Boolean is
S : Entity_Id;
begin
S := E;
while Present (S) and then S /= Standard_Standard loop
if Is_Generic_Instance (S)
and then Present (Freeze_Node (S))
and then not Analyzed (Freeze_Node (S))
then
return True;
end if;
S := Scope (S);
end loop;
return False;
end In_Unfrozen_Instance;
-------------------------
-- 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
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;
Param_Count : Natural := 0;
Parent_Formal : Entity_Id;
Parent_Subp : Entity_Id;
Scop : Entity_Id;
Subp : Entity_Id;
Prev_Orig : Node_Id;
-- Original node for an actual, which may have been rewritten. If the
-- actual is a function call that has been transformed from a selected
-- component, the original node is unanalyzed. Otherwise, it carries
-- semantic information used to generate additional actuals.
CW_Interface_Formals_Present : Boolean := False;
-- Start of processing for Expand_Call
begin
-- Expand the procedure call if the first actual has a dimension and if
-- the procedure is Put (Ada 2012).
if Ada_Version >= Ada_2012
and then Nkind (Call_Node) = N_Procedure_Call_Statement
and then Present (Parameter_Associations (Call_Node))
then
Expand_Put_Call_With_Symbol (Call_Node);
end if;
-- Ignore if previous error
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 (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 (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 (Call_Node)) = N_Indexed_Component then
Subp := Entity (Selector_Name (Prefix (Name (Call_Node))));
Parent_Subp := Empty;
-- Normal case
else
Subp := Entity (Name (Call_Node));
Parent_Subp := Alias (Subp);
-- Replace call to Raise_Exception by call to Raise_Exception_Always
-- if we can tell that the first parameter cannot possibly be null.
-- This improves efficiency by avoiding a run-time test.
-- We do not do this if Raise_Exception_Always does not exist, which
-- can happen in configurable run time profiles which provide only a
-- Raise_Exception.
if Is_RTE (Subp, RE_Raise_Exception)
and then RTE_Available (RE_Raise_Exception_Always)
then
declare
FA : constant Node_Id :=
Original_Node (First_Actual (Call_Node));
begin
-- The case we catch is where the first argument is obtained
-- using the Identity attribute (which must always be
-- non-null).
if Nkind (FA) = N_Attribute_Reference
and then Attribute_Name (FA) = Name_Identity
then
Subp := RTE (RE_Raise_Exception_Always);
Set_Name (Call_Node, New_Occurrence_Of (Subp, Loc));
end if;
end;
end if;
if Ekind (Subp) = E_Entry then
Parent_Subp := Empty;
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 deal
-- with this by transforming 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_Occurrence_Of (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_2005
and then Nkind (Call_Node) = N_Procedure_Call_Statement
and then
((Nkind (Parent (Call_Node)) = N_Triggering_Alternative
and then Triggering_Statement (Parent (Call_Node)) = Call_Node)
or else
(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_Root : Entity_Id := Subp;
begin
-- This may be a chain of renamings, find the root
if Present (Alias (Ren_Root)) then
Ren_Root := Alias (Ren_Root);
end if;
if Present (Original_Node (Parent (Parent (Ren_Root)))) then
Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
Rewrite (Call_Node,
Make_Entry_Call_Statement (Loc,
Name =>
New_Copy_Tree (Name (Ren_Decl)),
Parameter_Associations =>
New_Copy_List_Tree
(Parameter_Associations (Call_Node))));
return;
end if;
end if;
end;
end if;
-- First step, compute extra actuals, corresponding to any Extra_Formals
-- present. Note that we do not access Extra_Formals directly, instead
-- we simply note the presence of the extra formals as we process the
-- regular formals collecting corresponding actuals in Extra_Actuals.
-- We also generate any required range checks for actuals for in formals
-- 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???)
-- Special case: Thunks must not compute the extra actuals; they must
-- just propagate to the target primitive their extra actuals.
if Is_Thunk (Current_Scope)
and then Thunk_Entity (Current_Scope) = Subp
and then Present (Extra_Formals (Subp))
then
pragma Assert (Present (Extra_Formals (Current_Scope)));
declare
Target_Formal : Entity_Id;
Thunk_Formal : Entity_Id;
begin
Target_Formal := Extra_Formals (Subp);
Thunk_Formal := Extra_Formals (Current_Scope);
while Present (Target_Formal) loop
Add_Extra_Actual
(New_Occurrence_Of (Thunk_Formal, Loc), Thunk_Formal);
Target_Formal := Extra_Formal (Target_Formal);
Thunk_Formal := Extra_Formal (Thunk_Formal);
end loop;
while Is_Non_Empty_List (Extra_Actuals) loop
Add_Actual_Parameter (Remove_Head (Extra_Actuals));
end loop;
Expand_Actuals (Call_Node, Subp);
return;
end;
end if;
Formal := First_Formal (Subp);
Actual := First_Actual (Call_Node);
Param_Count := 1;
while Present (Formal) loop
-- Generate range check if required
if Do_Range_Check (Actual)
and then Ekind (Formal) = E_In_Parameter
then
Generate_Range_Check
(Actual, Etype (Formal), CE_Range_Check_Failed);
end if;
-- Prepare to examine current entry
Prev := Actual;
Prev_Orig := Original_Node (Prev);
-- Ada 2005 (AI-251): Check if any formal is a class-wide interface
-- to expand it in a further round.
CW_Interface_Formals_Present :=
CW_Interface_Formals_Present
or else
(Ekind (Etype (Formal)) = E_Class_Wide_Type
and then Is_Interface (Etype (Etype (Formal))))
or else
(Ekind (Etype (Formal)) = E_Anonymous_Access_Type
and then Is_Interface (Directly_Designated_Type
(Etype (Etype (Formal)))));
-- Create possible extra actual for constrained case. Usually, the
-- extra actual is of the form actual'constrained, but since this
-- attribute is only available for unconstrained records, TRUE is
-- expanded if the type of the formal happens to be constrained (for
-- instance when this procedure is inherited from an unconstrained
-- record to a constrained one) or if the actual has no discriminant
-- (its type is constrained). An exception to this is the case of a
-- private type without discriminants. In this case we pass FALSE
-- because the object has underlying discriminants with defaults.
if Present (Extra_Constrained (Formal)) then
if Ekind (Etype (Prev)) in Private_Kind
and then not Has_Discriminants (Base_Type (Etype (Prev)))
then
Add_Extra_Actual
(New_Occurrence_Of (Standard_False, Loc),
Extra_Constrained (Formal));
elsif Is_Constrained (Etype (Formal))
or else not Has_Discriminants (Etype (Prev))
then
Add_Extra_Actual
(New_Occurrence_Of (Standard_True, Loc),
Extra_Constrained (Formal));
-- Do not produce extra actuals for Unchecked_Union parameters.
-- Jump directly to the end of the loop.
elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
goto Skip_Extra_Actual_Generation;
else
-- If the actual is a type conversion, then the constrained
-- test applies to the actual, not the target type.
declare
Act_Prev : Node_Id;
begin
-- Test for unchecked conversions as well, which can occur
-- as out parameter actuals on calls to stream procedures.
Act_Prev := Prev;
while Nkind_In (Act_Prev, N_Type_Conversion,
N_Unchecked_Type_Conversion)
loop
Act_Prev := Expression (Act_Prev);
end loop;
-- If the expression is a conversion of a dereference, this
-- is internally generated code that manipulates addresses,
-- e.g. when building interface tables. No check should
-- occur in this case, and the discriminated object is not
-- directly a hand.
if not Comes_From_Source (Actual)
and then Nkind (Actual) = N_Unchecked_Type_Conversion
and then Nkind (Act_Prev) = N_Explicit_Dereference
then
Add_Extra_Actual
(New_Occurrence_Of (Standard_False, Loc),
Extra_Constrained (Formal));
else
Add_Extra_Actual
(Make_Attribute_Reference (Sloc (Prev),
Prefix =>
Duplicate_Subexpr_No_Checks
(Act_Prev, Name_Req => True),
Attribute_Name => Name_Constrained),
Extra_Constrained (Formal));
end if;
end;
end if;
end if;
-- Create possible extra actual for accessibility level
if Present (Extra_Accessibility (Formal)) then
-- Ada 2005 (AI-252): If the actual was rewritten as an Access
-- attribute, then the original actual may be an aliased object
-- occurring as the prefix in a call using "Object.Operation"
-- notation. In that case we must pass the level of the object,
-- so Prev_Orig is reset to Prev and the attribute will be
-- processed by the code for Access attributes further below.
if Prev_Orig /= Prev
and then Nkind (Prev) = N_Attribute_Reference
and then
Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
and then Is_Aliased_View (Prev_Orig)
then
Prev_Orig := Prev;
end if;
-- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
-- accessibility levels.
if Is_Thunk (Current_Scope) then
declare
Parm_Ent : Entity_Id;
begin
if Is_Controlling_Actual (Actual) then
-- Find the corresponding actual of the thunk
Parm_Ent := First_Entity (Current_Scope);
for J in 2 .. Param_Count loop
Next_Entity (Parm_Ent);
end loop;
-- Handle unchecked conversion of access types generated
-- in thunks (cf. Expand_Interface_Thunk).
elsif Is_Access_Type (Etype (Actual))
and then Nkind (Actual) = N_Unchecked_Type_Conversion
then
Parm_Ent := Entity (Expression (Actual));
else pragma Assert (Is_Entity_Name (Actual));
Parm_Ent := Entity (Actual);
end if;
Add_Extra_Actual
(New_Occurrence_Of (Extra_Accessibility (Parm_Ent), Loc),
Extra_Accessibility (Formal));
end;
elsif Is_Entity_Name (Prev_Orig) then
-- When passing an access parameter, or a renaming of an access
-- parameter, as the actual to another access parameter we need
-- to pass along the actual's own access level parameter. This
-- is done if we are within the scope of the formal access
-- parameter (if this is an inlined body the extra formal is
-- irrelevant).
if (Is_Formal (Entity (Prev_Orig))
or else
(Present (Renamed_Object (Entity (Prev_Orig)))
and then
Is_Entity_Name (Renamed_Object (Entity (Prev_Orig)))
and then
Is_Formal
(Entity (Renamed_Object (Entity (Prev_Orig))))))
and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
then
declare
Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
begin
pragma Assert (Present (Parm_Ent));
if Present (Extra_Accessibility (Parm_Ent)) then
Add_Extra_Actual
(New_Occurrence_Of
(Extra_Accessibility (Parm_Ent), Loc),
Extra_Accessibility (Formal));
-- If the actual access parameter does not have an
-- associated extra formal providing its scope level,
-- then treat the actual as having library-level
-- accessibility.
else
Add_Extra_Actual
(Make_Integer_Literal (Loc,
Intval => Scope_Depth (Standard_Standard)),
Extra_Accessibility (Formal));
end if;
end;
-- The actual is a normal access value, so just pass the level
-- of the actual's access type.
else
Add_Extra_Actual
(Dynamic_Accessibility_Level (Prev_Orig),
Extra_Accessibility (Formal));
end if;
-- If the actual is an access discriminant, then pass the level
-- of the enclosing object (RM05-3.10.2(12.4/2)).
elsif Nkind (Prev_Orig) = N_Selected_Component
and then Ekind (Entity (Selector_Name (Prev_Orig))) =
E_Discriminant
and then Ekind (Etype (Entity (Selector_Name (Prev_Orig)))) =
E_Anonymous_Access_Type
then
Add_Extra_Actual
(Make_Integer_Literal (Loc,
Intval => Object_Access_Level (Prefix (Prev_Orig))),
Extra_Accessibility (Formal));
-- All other cases
else
case Nkind (Prev_Orig) is
when N_Attribute_Reference =>
case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
-- For X'Access, pass on the level of the prefix X
when Attribute_Access =>
-- 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
when Attribute_Unchecked_Access |
Attribute_Unrestricted_Access =>
Add_Extra_Actual
(Make_Integer_Literal (Loc,
Intval => Scope_Depth (Standard_Standard)),
Extra_Accessibility (Formal));
-- No other cases of attributes returning access
-- values that can be passed to access parameters.
when others =>
raise Program_Error;
end case;
-- For allocators we pass the level of the execution of the
-- called subprogram, which is one greater than the current
-- scope level.
when N_Allocator =>
Add_Extra_Actual
(Make_Integer_Literal (Loc,
Intval => Scope_Depth (Current_Scope) + 1),
Extra_Accessibility (Formal));
-- 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
(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
-- 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_2005 then
-- 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)))
then
Install_Null_Excluding_Check (Prev);
end if;
-- Ada_Version < Ada_2005
else
if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
or else Access_Checks_Suppressed (Subp)
then
null;
elsif Debug_Flag_J then
null;
elsif not Comes_From_Source (Prev) then
null;
elsif Is_Entity_Name (Prev)
and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
then
null;
elsif Nkind_In (Prev, N_Allocator, N_Attribute_Reference) then
null;
-- Suppress null checks when passing to access parameters of Java
-- and CIL subprograms. (Should this be done for other foreign
-- conventions as well ???)
elsif Convention (Subp) = Convention_Java
or else Convention (Subp) = Convention_CIL
then
null;
else
Install_Null_Excluding_Check (Prev);
end if;
end if;
-- Perform appropriate validity checks on parameters that
-- are entities.
if Validity_Checks_On then
if (Ekind (Formal) = E_In_Parameter
and then Validity_Check_In_Params)
or else
(Ekind (Formal) = E_In_Out_Parameter
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
-- meets this condition), it has not been expanded yet. It will
-- be copied in the validity code that follows, and has to be
-- expanded appropriately, so reanalyze it.
-- What we do is just to unset analyzed bits on prefixes till
-- we reach something that does not have a prefix.
declare
Nod : Node_Id;
begin
Nod := Actual;
while Nkind_In (Nod, N_Indexed_Component,
N_Selected_Component)
loop
Set_Analyzed (Nod, False);
Nod := Prefix (Nod);
end loop;
end;
Ensure_Valid (Actual);
end if;
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.
if Comes_From_Source (Call_Node)
and then Ekind (Formal) /= E_In_Parameter
and then Validity_Checks_On
and then Validity_Check_Default
and then not Validity_Check_Subscripts
then
Check_Valid_Lvalue_Subscripts (Actual);
end if;
-- Mark any scalar OUT parameter that is a simple variable as no
-- longer known to be valid (unless the type is always valid). This
-- reflects the fact that if an OUT parameter is never set in a
-- procedure, then it can become invalid on the procedure return.
if Ekind (Formal) = E_Out_Parameter
and then Is_Entity_Name (Actual)
and then Ekind (Entity (Actual)) = E_Variable
and then not Is_Known_Valid (Etype (Actual))
then
Set_Is_Known_Valid (Entity (Actual), False);
end if;
-- For an OUT or IN OUT parameter, if the actual is an entity, then
-- clear current values, since they can be clobbered. We are probably
-- doing this in more places than we need to, but better safe than
-- sorry when it comes to retaining bad current values.
if Ekind (Formal) /= E_In_Parameter
and then Is_Entity_Name (Actual)
and then Present (Entity (Actual))
then
declare
Ent : constant Entity_Id := Entity (Actual);
Sav : Node_Id;
begin
-- For an OUT or IN OUT parameter that is an assignable entity,
-- we do not want to clobber the Last_Assignment field, since
-- if it is set, it was precisely because it is indeed an OUT
-- or IN OUT parameter. We do reset the Is_Known_Valid flag
-- since the subprogram could have returned in invalid value.
if Ekind_In (Formal, E_Out_Parameter, E_In_Out_Parameter)
and then Is_Assignable (Ent)
then
Sav := Last_Assignment (Ent);
Kill_Current_Values (Ent);
Set_Last_Assignment (Ent, Sav);
Set_Is_Known_Valid (Ent, False);
-- For all other cases, just kill the current values
else
Kill_Current_Values (Ent);
end if;
end;
end if;
-- If the formal is class wide and the actual is an aggregate, force
-- evaluation so that the back end who does not know about class-wide
-- type, does not generate a temporary of the wrong size.
if not Is_Class_Wide_Type (Etype (Formal)) then
null;
elsif Nkind (Actual) = N_Aggregate
or else (Nkind (Actual) = N_Qualified_Expression
and then Nkind (Expression (Actual)) = N_Aggregate)
then
Force_Evaluation (Actual);
end if;
-- In a remote call, if the formal is of a class-wide type, check
-- that the actual meets the requirements described in E.4(18).
if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
Insert_Action (Actual,
Make_Transportable_Check (Loc,
Duplicate_Subexpr_Move_Checks (Actual)));
end if;
-- This label is required when skipping extra actual generation for
-- Unchecked_Union parameters.
<<Skip_Extra_Actual_Generation>>
Param_Count := Param_Count + 1;
Next_Actual (Actual);
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 returned
-- routine 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 the 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 (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 (Call_Node)) = N_Assignment_Statement then
Ass := Parent (Call_Node);
elsif Nkind (Parent (Call_Node)) = N_Qualified_Expression
and then Nkind (Parent (Parent (Call_Node))) =
N_Assignment_Statement
then
Ass := Parent (Parent (Call_Node));
elsif Nkind (Parent (Call_Node)) = N_Explicit_Dereference
and then Nkind (Parent (Parent (Call_Node))) =
N_Assignment_Statement
then
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 (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))",
Call_Node, Root_Type (Etype (Name (Ass))));
else
Propagate_Tag (Name (Ass), Call_Node);
end if;
elsif Etype (Call_Node) /= Root_Type (Etype (Name (Ass))) then
Error_Msg_NE
("tag-indeterminate expression must have type&"
& "(RM 5.2 (6))",
Call_Node, Root_Type (Etype (Name (Ass))));
else
Propagate_Tag (Name (Ass), Call_Node);
end if;
-- The call will be rewritten as a dispatching call, and
-- expanded as such.
return;
end if;
end;
end if;
-- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
-- it to point to the correct secondary virtual table
if Nkind (Call_Node) in N_Subprogram_Call
and then CW_Interface_Formals_Present
then
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 (Call_Node) in N_Subprogram_Call
and then Present (Controlling_Argument (Call_Node))
then
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;
begin
if not Is_Limited_Type (Typ) then
Eq_Prim_Op := Find_Prim_Op (Typ, Name_Op_Eq);
end if;
if Tagged_Type_Expansion then
Expand_Dispatching_Call (Call_Node);
-- The following return is worrisome. Is it really OK to skip
-- all remaining processing in this procedure ???
return;
-- VM targets
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_Occurrence_Of
(First_Tag_Component (Typ), Loc)),
Right_Opnd =>
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Typ,
New_Value (Next_Actual (Param))),
Selector_Name =>
New_Occurrence_Of
(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.
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
-- call, because it will be rewritten as a protected subprogram call
-- and reanalyzed (see Expand_Protected_Subprogram_Call).
elsif Is_Protected_Type (Scope (Subp))
and then (Ekind (Subp) = E_Procedure
or else Ekind (Subp) = E_Function)
then
null;
-- During that loop we gathered the extra actuals (the ones that
-- correspond to Extra_Formals), so now they can be appended.
else
while Is_Non_Empty_List (Extra_Actuals) loop
Add_Actual_Parameter (Remove_Head (Extra_Actuals));
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.
Expand_Actuals (Call_Node, Subp);
-- Verify that the actuals do not share storage. This check must be done
-- on the caller side rather that inside the subprogram to avoid issues
-- of parameter passing.
if Check_Aliasing_Of_Parameters then
Apply_Parameter_Aliasing_Checks (Call_Node, Subp);
end if;
-- 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 (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);
else
Parent_Subp := Ultimate_Alias (Parent_Subp);
end if;
-- The below setting of Entity is suspect, see F109-018 discussion???
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 (Call_Node), Parent_Subp);
end if;
-- Inspect all formals of derived subprogram Subp. Compare parameter
-- types with the parent subprogram and check whether an actual may
-- need a type conversion to the corresponding formal of the parent
-- subprogram.
-- Not clear whether intrinsic subprograms need such conversions. ???
if not Is_Intrinsic_Subprogram (Parent_Subp)
or else Is_Generic_Instance (Parent_Subp)
then
declare
procedure Convert (Act : Node_Id; Typ : Entity_Id);
-- Rewrite node Act as a type conversion of Act to Typ. Analyze
-- and resolve the newly generated construct.
-------------
-- Convert --
-------------
procedure Convert (Act : Node_Id; Typ : Entity_Id) is
begin
Rewrite (Act, OK_Convert_To (Typ, Relocate_Node (Act)));
Analyze (Act);
Resolve (Act, Typ);
end Convert;
-- Local variables
Actual_Typ : Entity_Id;
Formal_Typ : Entity_Id;
Parent_Typ : Entity_Id;
begin
Actual := First_Actual (Call_Node);
Formal := First_Formal (Subp);
Parent_Formal := First_Formal (Parent_Subp);
while Present (Formal) loop
Actual_Typ := Etype (Actual);
Formal_Typ := Etype (Formal);
Parent_Typ := Etype (Parent_Formal);
-- For an IN parameter of a scalar type, the parent formal
-- type and derived formal type differ or the parent formal
-- type and actual type do not match statically.
if Is_Scalar_Type (Formal_Typ)
and then Ekind (Formal) = E_In_Parameter
and then Formal_Typ /= Parent_Typ
and then
not Subtypes_Statically_Match (Parent_Typ, Actual_Typ)
and then not Raises_Constraint_Error (Actual)
then
Convert (Actual, Parent_Typ);
Enable_Range_Check (Actual);
-- If the actual has been marked as requiring a range
-- check, then generate it here.
if Do_Range_Check (Actual) then
Generate_Range_Check
(Actual, Etype (Formal), CE_Range_Check_Failed);
end if;
-- For access types, the parent formal type and actual type
-- differ.
elsif Is_Access_Type (Formal_Typ)
and then Base_Type (Parent_Typ) /= Base_Type (Actual_Typ)
then
if Ekind (Formal) /= E_In_Parameter then
Convert (Actual, Parent_Typ);
elsif Ekind (Parent_Typ) = E_Anonymous_Access_Type
and then Designated_Type (Parent_Typ) /=
Designated_Type (Actual_Typ)
and then not Is_Controlling_Formal (Formal)
then
-- This unchecked conversion is not necessary unless
-- inlining is enabled, because in that case the type
-- mismatch may become visible in the body about to be
-- inlined.
Rewrite (Actual,
Unchecked_Convert_To (Parent_Typ,
Relocate_Node (Actual)));
Analyze (Actual);
Resolve (Actual, Parent_Typ);
end if;
-- If there is a change of representation, then generate a
-- warning, and do the change of representation.
elsif not Same_Representation (Formal_Typ, Parent_Typ) then
Error_Msg_N
("??change of representation required", Actual);
Convert (Actual, Parent_Typ);
-- For array and record types, the parent formal type and
-- derived formal type have different sizes or pragma Pack
-- status.
elsif ((Is_Array_Type (Formal_Typ)
and then Is_Array_Type (Parent_Typ))
or else
(Is_Record_Type (Formal_Typ)
and then Is_Record_Type (Parent_Typ)))
and then
(Esize (Formal_Typ) /= Esize (Parent_Typ)
or else Has_Pragma_Pack (Formal_Typ) /=
Has_Pragma_Pack (Parent_Typ))
then
Convert (Actual, Parent_Typ);
end if;
Next_Actual (Actual);
Next_Formal (Formal);
Next_Formal (Parent_Formal);
end loop;
end;
end if;
Orig_Subp := Subp;
Subp := Parent_Subp;
end if;
-- Deal with case where call is an explicit dereference
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 (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 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 (Call_Node));
T : constant Entity_Id :=
Equivalent_Type (Base_Type (Etype (Ptr)));
D_T : constant Entity_Id :=
Designated_Type (Base_Type (Etype (Ptr)));
begin
Obj :=
Make_Selected_Component (Loc,
Prefix => Unchecked_Convert_To (T, Ptr),
Selector_Name =>
New_Occurrence_Of (First_Entity (T), Loc));
Nam :=
Make_Selected_Component (Loc,
Prefix => Unchecked_Convert_To (T, Ptr),
Selector_Name =>
New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
Nam :=
Make_Explicit_Dereference (Loc,
Prefix => Nam);
if Present (Parameter_Associations (Call_Node)) then
Parm := Parameter_Associations (Call_Node);
else
Parm := New_List;
end if;
Prepend (Obj, Parm);
if Etype (D_T) = Standard_Void_Type then
Call :=
Make_Procedure_Call_Statement (Loc,
Name => Nam,
Parameter_Associations => Parm);
else
Call :=
Make_Function_Call (Loc,
Name => Nam,
Parameter_Associations => Parm);
end if;
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.
-- We analyze separately the prefix and the object, and set
-- the checks on the prefix that would otherwise be emitted
-- when resolving a call.
Rewrite (Call_Node, Call);
Analyze (Nam);
Apply_Access_Check (Nam);
Analyze (Obj);
return;
end;
end if;
end if;
-- If this is a call to an intrinsic subprogram, then perform the
-- appropriate expansion to the corresponding tree node and we
-- are all done (since after that the call is gone).
-- 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.
if Is_Intrinsic_Subprogram (Subp) then
Expand_Intrinsic_Call (Call_Node, Subp);
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 (Call_Node, Etype (Orig_Subp));
end if;
return;
end if;
if Ekind_In (Subp, E_Function, E_Procedure) then
-- We perform two simple optimization on calls:
-- a) replace calls to null procedures unconditionally;
-- b) for To_Address, just do an unchecked conversion. Not only is
-- this efficient, but it also avoids order of elaboration problems
-- when address clauses are inlined (address expression elaborated
-- at the wrong point).
-- We perform these optimization regardless of whether we are in the
-- main unit or in a unit in the context of the main unit, to ensure
-- that tree generated is the same in both cases, for CodePeer use.
if Is_RTE (Subp, RE_To_Address) then
Rewrite (Call_Node,
Unchecked_Convert_To
(RTE (RE_Address), Relocate_Node (First_Actual (Call_Node))));
return;
elsif Is_Null_Procedure (Subp) then
Rewrite (Call_Node, Make_Null_Statement (Loc));
return;
end if;
-- Handle inlining. No action needed if the subprogram is not inlined
if not Is_Inlined (Subp) then
null;
-- Handle frontend inlining
elsif not Back_End_Inlining then
Inlined_Subprogram : declare
Bod : Node_Id;
Must_Inline : Boolean := False;
Spec : constant Node_Id := Unit_Declaration_Node (Subp);
begin
-- Verify that the body to inline has already been seen, and
-- that if the body is in the current unit the inlining does
-- not occur earlier. This avoids order-of-elaboration problems
-- in the back end.
-- This should be documented in sinfo/einfo ???
if No (Spec)
or else Nkind (Spec) /= N_Subprogram_Declaration
or else No (Body_To_Inline (Spec))
then
Must_Inline := False;
-- If this an inherited function that returns a private type,
-- do not inline if the full view is an unconstrained array,
-- because such calls cannot be inlined.
elsif Present (Orig_Subp)
and then Is_Array_Type (Etype (Orig_Subp))
and then not Is_Constrained (Etype (Orig_Subp))
then
Must_Inline := False;
elsif In_Unfrozen_Instance (Scope (Subp)) then
Must_Inline := False;
else
Bod := Body_To_Inline (Spec);
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
Earlier_In_Extended_Unit (Sloc (Bod), Loc))
then
Must_Inline := True;
-- If we are compiling a package body that is not the main
-- unit, it must be for inlining/instantiation purposes,
-- in which case we inline the call to insure that the same
-- temporaries are generated when compiling the body by
-- itself. Otherwise link errors can occur.
-- If the function being called is itself in the main unit,
-- we cannot inline, because there is a risk of double
-- elaboration and/or circularity: the inlining can make
-- 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 (Call_Node))
and then In_Package_Body
then
Must_Inline := not In_Extended_Main_Source_Unit (Subp);
end if;
end if;
if Must_Inline then
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
else
-- Let the back end handle it
Add_Inlined_Body (Subp, Call_Node);
if Front_End_Inlining
and then Nkind (Spec) = N_Subprogram_Declaration
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)?",
Call_Node, Subp);
end if;
end if;
end Inlined_Subprogram;
-- Back end inlining: let the back end handle it
elsif No (Unit_Declaration_Node (Subp))
or else Nkind (Unit_Declaration_Node (Subp)) /=
N_Subprogram_Declaration
or else No (Body_To_Inline (Unit_Declaration_Node (Subp)))
or else Nkind (Body_To_Inline (Unit_Declaration_Node (Subp))) in
N_Entity
then
Add_Inlined_Body (Subp, Call_Node);
-- Front end expansion of simple functions returning unconstrained
-- types (see Check_And_Split_Unconstrained_Function). Note that the
-- case of a simple renaming (Body_To_Inline in N_Entity above, see
-- also Build_Renamed_Body) cannot be expanded here because this may
-- give rise to order-of-elaboration issues for the types of the
-- parameters of the subprogram, if any.
else
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
end if;
end if;
-- Check for protected subprogram. This is either an intra-object call,
-- or a protected function call. Protected procedure calls are rewritten
-- as entry calls and handled accordingly.
-- In Ada 2005, this may be an indirect call to an access parameter that
-- is an access_to_subprogram. In that case the anonymous type has a
-- scope that is a protected operation, but the call is a regular one.
-- In either case do not expand call if subprogram is eliminated.
Scop := Scope (Subp);
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)
then
-- If the call is an internal one, it is rewritten as a call to the
-- corresponding unprotected subprogram.
Expand_Protected_Subprogram_Call (Call_Node, Subp, Scop);
end if;
-- 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)) then
if not Is_Limited_View (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;
end Expand_Call;
-------------------------------
-- Expand_Ctrl_Function_Call --
-------------------------------
procedure Expand_Ctrl_Function_Call (N : Node_Id) is
function Is_Element_Reference (N : Node_Id) return Boolean;
-- Determine whether node N denotes a reference to an Ada 2012 container
-- element.
--------------------------
-- Is_Element_Reference --
--------------------------
function Is_Element_Reference (N : Node_Id) return Boolean is
Ref : constant Node_Id := Original_Node (N);
begin
-- Analysis marks an element reference by setting the generalized
-- indexing attribute of an indexed component before the component
-- is rewritten into a function call.
return
Nkind (Ref) = N_Indexed_Component
and then Present (Generalized_Indexing (Ref));
end Is_Element_Reference;
-- Local variables
Is_Elem_Ref : constant Boolean := Is_Element_Reference (N);
-- Start of processing for Expand_Ctrl_Function_Call
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);
-- When the temporary function result appears inside a case expression
-- or an if expression, its lifetime must be extended to match that of
-- the context. If not, the function result will be finalized too early
-- and the evaluation of the expression could yield incorrect result. An
-- exception to this rule are references to Ada 2012 container elements.
-- Such references must be finalized at the end of each iteration of the
-- related quantified expression, otherwise the container will remain
-- busy.
if not Is_Elem_Ref
and then Within_Case_Or_If_Expression (N)
and then Nkind (N) = N_Explicit_Dereference
then
Set_Is_Processed_Transient (Entity (Prefix (N)));
end if;
end Expand_Ctrl_Function_Call;
----------------------------------------
-- Expand_N_Extended_Return_Statement --
----------------------------------------
-- If there is a Handled_Statement_Sequence, we rewrite this:
-- return Result : T := <expression> do
-- <handled_seq_of_stms>
-- end return;
-- to be:
-- declare
-- Result : T := <expression>;
-- begin
-- <handled_seq_of_stms>
-- return Result;
-- end;
-- Otherwise (no Handled_Statement_Sequence), we rewrite this:
-- return Result : T := <expression>;
-- to be:
-- return <expression>;
-- unless it's build-in-place or there's no <expression>, in which case
-- we generate:
-- declare
-- Result : T := <expression>;
-- begin
-- return Result;
-- end;
-- 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.
-- 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).
procedure Expand_N_Extended_Return_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
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
--------------------------
-- Build_Heap_Allocator --
--------------------------
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));
-- Processing for build-in-place object allocation. This is disabled
-- on .NET/JVM because the targets do not support pools.
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;
begin
-- Generate:
-- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
Pool_Id := Make_Temporary (Loc, 'P');
Append_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pool_Id,
Subtype_Mark =>
New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc),
Name =>
Make_Explicit_Dereference (Loc,
Prefix =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Base_Pool), Loc),
Parameter_Associations => New_List (
Make_Explicit_Dereference (Loc,
Prefix =>
New_Occurrence_Of (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;
-- Generate:
-- type Ptr_Typ is access Desig_Typ;
Ptr_Typ := Make_Temporary (Loc, 'P');
Append_To (Decls,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ptr_Typ,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
New_Occurrence_Of (Desig_Typ, Loc))));
-- Perform minor decoration in order to set the master and the
-- storage pool attributes.
Set_Ekind (Ptr_Typ, E_Access_Type);
Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
-- Create the temporary, generate:
-- Local_Id : Ptr_Typ;
Local_Id := Make_Temporary (Loc, 'T');
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Local_Id,
Object_Definition =>
New_Occurrence_Of (Ptr_Typ, Loc)));
-- Allocate the object, generate:
-- Local_Id := <Alloc_Expr>;
Append_To (Stmts,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Local_Id, Loc),
Expression => Alloc_Expr));
-- Generate:
-- Temp_Id := Temp_Typ (Local_Id);
Append_To (Stmts,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Temp_Id, Loc),
Expression =>
Unchecked_Convert_To (Temp_Typ,
New_Occurrence_Of (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_Occurrence_Of (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_Occurrence_Of (Temp_Id, Loc),
Expression => Alloc_Expr);
end if;
end Build_Heap_Allocator;
---------------------------
-- Move_Activation_Chain --
---------------------------
function Move_Activation_Chain return Node_Id is
begin
return
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Move_Activation_Chain), Loc),
Parameter_Associations => New_List (
-- Source chain
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uChain),
Attribute_Name => Name_Unrestricted_Access),
-- Destination chain
New_Occurrence_Of
(Build_In_Place_Formal (Par_Func, BIP_Activation_Chain), Loc),
-- New master
New_Occurrence_Of
(Build_In_Place_Formal (Par_Func, BIP_Task_Master), Loc)));
end Move_Activation_Chain;
-- Start of processing for Expand_N_Extended_Return_Statement
begin
-- Given that functionality of interface thunks is simple (just displace
-- the pointer to the object) they are always handled by means of
-- simple return statements.
pragma Assert (not Is_Thunk (Current_Scope));
if Nkind (Ret_Obj_Decl) = N_Object_Declaration then
Exp := Expression (Ret_Obj_Decl);
else
Exp := Empty;
end if;
HSS := Handled_Statement_Sequence (N);
-- 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
Flag_Decl : Node_Id;