-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
with 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_Ch12; use Sem_Ch12;
with Sem_Dist; use Sem_Dist;
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 Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with Validsw; use Validsw;
--
-- 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:
+ -- 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.
-- 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 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).
-- reference to the object itself, and the call becomes a call to the
-- corresponding protected subprogram.
+ function Is_Null_Procedure (Subp : Entity_Id) return Boolean;
+ -- Predicate to recognize stubbed procedures and null procedures, which
+ -- can be inlined unconditionally in all cases.
+
----------------------------------------------
-- Add_Access_Actual_To_Build_In_Place_Call --
----------------------------------------------
Final_List_Actual : Node_Id;
Final_List_Formal : Node_Id;
Is_Ctrl_Result : constant Boolean :=
- Controlled_Type
+ Needs_Finalization
(Underlying_Type (Etype (Function_Id)));
begin
-- No such extra parameter is needed if there are no controlled parts.
- -- The test for Controlled_Type accounts for class-wide results (which
- -- potentially have controlled parts, even if the root type doesn't),
- -- and the test for a tagged result type is needed because calls to
- -- such a function can in general occur in dispatching contexts, which
- -- must be treated the same as a call to class-wide functions. Both of
- -- these situations require that a finalization list be passed.
-
- if not Is_Ctrl_Result
- and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
- then
+ -- The test for Needs_Finalization accounts for class-wide results
+ -- (which potentially have controlled parts, even if the root type
+ -- doesn't), and the test for a tagged result type is needed because
+ -- calls to such a function can in general occur in dispatching
+ -- contexts, which must be treated the same as a call to class-wide
+ -- functions. Both of these situations require that a finalization list
+ -- be passed.
+
+ if not Needs_BIP_Final_List (Function_Id) then
return;
end if;
-- Create the actual which is a pointer to the appropriate finalization
-- list. Acc_Type is present if and only if this call is the
- -- initialization of an allocator. Use the Current_Scope or the Acc_Type
- -- as appropriate.
+ -- initialization of an allocator. Use the Current_Scope or the
+ -- Acc_Type as appropriate.
if Present (Acc_Type)
and then (Ekind (Acc_Type) = E_Anonymous_Access_Type
declare
Activation_Chain_Actual : Node_Id;
Activation_Chain_Formal : Node_Id;
+
begin
-- Locate implicit activation chain parameter in the called function
-- 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
-- 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
+ -- (before expansion of the packed reference) so that the proper
-- expansion of assignment to a packed component can take place.
declare
Expression => Expr));
end;
end if;
-
end Add_Call_By_Copy_Code;
----------------------------------
-- 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 Treat_As_Volatile (Entity (Actual))
+ and then Is_Volatile (Entity (Actual))
and then not Is_By_Reference_Type (Etype (Actual))
and then not Is_Scalar_Type (Etype (Entity (Actual)))
- and then not Treat_As_Volatile (E_Formal)
+ and then not Is_Volatile (E_Formal)
then
Add_Call_By_Copy_Code;
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, Etype (Actual))
+ or else
+ (Ekind (Formal) = E_In_Out_Parameter
+ and then not In_Subrange_Of (Etype (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;
-- Processing for IN parameters
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.
+ -- 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???
Make_Identifier (Loc, Chars (EF))));
Analyze_And_Resolve (Expr, Etype (EF));
+
+ if Nkind (N) = N_Function_Call then
+ Set_Is_Accessibility_Actual (Parent (Expr));
+ end if;
end Add_Extra_Actual;
---------------------------
else
Indic :=
- (Subtype_Indication
- (Type_Definition (Original_Node (Parent (S)))));
+ Subtype_Indication
+ (Type_Definition (Original_Node (Parent (S))));
if Nkind (Indic) = N_Subtype_Indication then
Par := Entity (Subtype_Mark (Indic));
or else not In_Open_Scopes (Scope (Par))
then
return Empty;
-
else
Gen_Par := Generic_Parent_Type (Parent (Par));
end if;
Scop : Entity_Id;
Subp : Entity_Id;
- Prev_Orig : Node_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
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 and collect the
- -- corresponding actuals in Extra_Actuals.
+ -- 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 as we go
- -- through the loop, since this is a convenient place to do this.
+ -- 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???)
Formal := First_Formal (Subp);
Actual := First_Actual (N);
Param_Count := 1;
while Present (Formal) loop
- -- Generate range check if required (not activated yet ???)
+ -- Generate range check if required
--- if Do_Range_Check (Actual) then
--- Set_Do_Range_Check (Actual, False);
--- Generate_Range_Check
--- (Actual, Etype (Formal), CE_Range_Check_Failed);
--- end if;
+ if Do_Range_Check (Actual)
+ and then Ekind (Formal) = E_In_Parameter
+ then
+ Set_Do_Range_Check (Actual, False);
+ Generate_Range_Check
+ (Actual, Etype (Formal), CE_Range_Check_Failed);
+ end if;
-- Prepare to examine current entry
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 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
when Attribute_Access =>
Add_Extra_Actual
(Make_Integer_Literal (Loc,
- Intval =>
- Object_Access_Level (Prefix (Prev_Orig))),
- Extra_Accessibility (Formal));
+ Intval =>
+ Object_Access_Level
+ (Prefix (Prev_Orig))),
+ Extra_Accessibility (Formal));
-- Treat the unchecked attributes as library-level
end case;
- -- For allocators we pass the level of the execution of
- -- the called subprogram, which is one greater than the
- -- current scope level.
+ -- 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 => Type_Access_Level (Etype (Prev))),
Extra_Accessibility (Formal));
-
end case;
end if;
end if;
-- 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!
+ -- or IN OUT parameter! We do reset the Is_Known_Valid flag
+ -- since the subprogram could have returned in invalid value.
if (Ekind (Formal) = E_Out_Parameter
or else
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
if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
and then Present (Controlling_Argument (N))
then
- if VM_Target = No_VM then
+ if Tagged_Type_Expansion then
Expand_Dispatching_Call (N);
-- The following return is worrisome. Is it really OK to
return;
- -- Expansion of a dispatching call results in an indirect call, which
- -- in turn causes current values to be killed (see Resolve_Call), so
- -- on VM targets we do the call here to ensure consistent warnings
- -- between VM and non-VM targets.
-
else
+ Apply_Tag_Checks (N);
+
+ -- 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;
end if;
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
+ Set_Do_Range_Check (Actual, False);
+ Generate_Range_Check
+ (Actual, Etype (Formal), CE_Range_Check_Failed);
+ end if;
+
-- For access types, the parent formal type and actual type
-- differ.
Unchecked_Convert_To (Parent_Typ,
Relocate_Node (Actual)));
+ -- If the relocated node is a function call then it
+ -- can be part of the expansion of the predefined
+ -- equality operator of a tagged type and we may
+ -- need to adjust its SCIL dispatching node.
+
+ if Generate_SCIL
+ and then Nkind (Actual) /= N_Null
+ and then Nkind (Expression (Actual))
+ = N_Function_Call
+ then
+ Adjust_SCIL_Node (Actual, Expression (Actual));
+ end if;
+
Analyze (Actual);
Resolve (Actual, Parent_Typ);
end if;
if Ekind (Subp) = E_Function
or else Ekind (Subp) = 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 Inspector use.
+
+ if Is_RTE (Subp, RE_To_Address) then
+ Rewrite (N,
+ Unchecked_Convert_To
+ (RTE (RE_Address), Relocate_Node (First_Actual (N))));
+ return;
+
+ elsif Is_Null_Procedure (Subp) then
+ Rewrite (N, Make_Null_Statement (Loc));
+ return;
+ end if;
+
if Is_Inlined (Subp) then
Inlined_Subprogram : declare
Scop : constant Entity_Id := Scope (Subp);
function In_Unfrozen_Instance return Boolean;
- -- If the subprogram comes from an instance in the same
- -- unit, and the instance is not yet frozen, inlining might
- -- trigger order-of-elaboration problems in gigi.
+ -- If the subprogram comes from an instance in the same unit,
+ -- and the instance is not yet frozen, inlining might trigger
+ -- order-of-elaboration problems in gigi.
--------------------------
-- In_Unfrozen_Instance --
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.
+ -- 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 In_Same_Extended_Unit (Sloc (Spec), Loc)
then
Cannot_Inline
- ("cannot inline& (body not seen yet)?",
- N, Subp);
+ ("cannot inline& (body not seen yet)?", N, Subp);
end if;
end if;
end Inlined_Subprogram;
end if;
end if;
- -- Check for a 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.
+ -- 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 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.
Scop := Scope (Subp);
and then Is_Protected_Type (Scop)
and then Ekind (Subp) /= E_Subprogram_Type
then
- -- If the call is an internal one, it is rewritten as a call to
- -- to the corresponding unprotected subprogram.
+ -- If the call is an internal one, it is rewritten as a call to the
+ -- corresponding unprotected subprogram.
Expand_Protected_Subprogram_Call (N, Subp, Scop);
end if;
- -- Functions returning controlled objects need special attention
- -- If the return type is limited the context is an initialization
- -- and different processing applies.
+ -- Functions returning controlled objects need special attention:
+ -- if the return type is limited, the context is an initialization
+ -- and different processing applies. If the call is to a protected
+ -- function, the expansion above will call Expand_Call recusively.
+ -- To prevent a double attachment, check that the current call is
+ -- not a rewriting of a protected function call.
- if Controlled_Type (Etype (Subp))
+ if Needs_Finalization (Etype (Subp))
and then not Is_Inherently_Limited_Type (Etype (Subp))
- and then not Is_Limited_Interface (Etype (Subp))
+ and then
+ (No (First_Formal (Subp))
+ or else
+ not Is_Concurrent_Record_Type (Etype (First_Formal (Subp))))
then
Expand_Ctrl_Function_Call (N);
end if;
- -- Test for First_Optional_Parameter, and if so, truncate parameter
- -- list if there are optional parameters at the trailing end.
- -- Note we never delete procedures for call via a pointer.
+ -- Test for First_Optional_Parameter, and if so, truncate parameter list
+ -- if there are optional parameters at the trailing end.
+ -- Note: we never delete procedures for call via a pointer.
if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
and then Present (First_Optional_Parameter (Subp))
Last_Keep_Arg : Node_Id;
begin
- -- Last_Keep_Arg will hold the last actual that should be
- -- retained. If it remains empty at the end, it means that
- -- all parameters are optional.
+ -- Last_Keep_Arg will hold the last actual that should be kept.
+ -- If it remains empty at the end, it means that all parameters
+ -- are optional.
Last_Keep_Arg := Empty;
- -- Find first optional parameter, must be present since we
- -- checked the validity of the parameter before setting it.
+ -- Find first optional parameter, must be present since we checked
+ -- the validity of the parameter before setting it.
Formal := First_Formal (Subp);
Actual := First_Actual (N);
(Passoc, Next_Named_Actual (Parent (Temp)));
end loop;
end;
+
end if;
end;
end if;
Is_Unc : constant Boolean :=
Is_Array_Type (Etype (Subp))
and then not Is_Constrained (Etype (Subp));
- -- If the type returned by the function is unconstrained and the
- -- call can be inlined, special processing is required.
-
- function Is_Null_Procedure return Boolean;
- -- Predicate to recognize stubbed procedures and null procedures, for
- -- which there is no need for the full inlining mechanism.
+ -- If the type returned by the function is unconstrained and the call
+ -- can be inlined, special processing is required.
procedure Make_Exit_Label;
- -- Build declaration for exit label to be used in Return statements
+ -- Build declaration for exit label to be used in Return statements,
+ -- sets Exit_Lab (the label node) and Lab_Decl (corresponding implcit
+ -- declaration).
function Process_Formals (N : Node_Id) return Traverse_Result;
- -- Replace occurrence of a formal with the corresponding actual, or
- -- the thunk generated for it.
+ -- Replace occurrence of a formal with the corresponding actual, or the
+ -- thunk generated for it.
function Process_Sloc (Nod : Node_Id) return Traverse_Result;
- -- If the call being expanded is that of an internal subprogram,
- -- set the sloc of the generated block to that of the call itself,
- -- so that the expansion is skipped by the -next- command in gdb.
+ -- If the call being expanded is that of an internal subprogram, set the
+ -- sloc of the generated block to that of the call itself, so that the
+ -- expansion is skipped by the "next" command in gdb.
-- Same processing for a subprogram in a predefined file, e.g.
- -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
- -- to simplify our own development.
+ -- Ada.Tags. If Debug_Generated_Code is true, suppress this change to
+ -- simplify our own development.
procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
-- If the function body is a single expression, replace call with
function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
-- Determine whether a formal parameter is used only once in Orig_Bod
- -----------------------
- -- Is_Null_Procedure --
- -----------------------
-
- function Is_Null_Procedure return Boolean is
- Decl : constant Node_Id := Unit_Declaration_Node (Subp);
-
- begin
- if Ekind (Subp) /= E_Procedure then
- return False;
-
- elsif Nkind (Orig_Bod) /= N_Subprogram_Body then
- return False;
-
- -- Check if this is an Ada 2005 null procedure
-
- elsif Nkind (Decl) = N_Subprogram_Declaration
- and then Null_Present (Specification (Decl))
- then
- return True;
-
- -- Check if the body contains only a null statement, followed by the
- -- return statement added during expansion.
-
- else
- declare
- Stat : constant Node_Id :=
- First
- (Statements (Handled_Statement_Sequence (Orig_Bod)));
-
- Stat2 : constant Node_Id := Next (Stat);
-
- begin
- return
- Nkind (Stat) = N_Null_Statement
- and then
- (No (Stat2)
- or else
- (Nkind (Stat2) = N_Simple_Return_Statement
- and then No (Next (Stat2))));
- end;
- end if;
- end Is_Null_Procedure;
-
---------------------
-- Make_Exit_Label --
---------------------
-- Start of processing for Expand_Inlined_Call
begin
- -- Check for special case of To_Address call, and if so, just do an
- -- unchecked conversion instead of expanding the call. Not only is this
- -- more efficient, but it also avoids problem with order of elaboration
- -- when address clauses are inlined (address expression elaborated at
- -- wrong point).
-
- if Subp = RTE (RE_To_Address) then
- Rewrite (N,
- Unchecked_Convert_To
- (RTE (RE_Address),
- Relocate_Node (First_Actual (N))));
- return;
-
- elsif Is_Null_Procedure then
- Rewrite (N, Make_Null_Statement (Loc));
- return;
- end if;
-- Check for an illegal attempt to inline a recursive procedure. If the
-- subprogram has parameters this is detected when trying to supply a
-- its value is captured in a renaming declaration. Otherwise
-- declare a local constant initialized with the actual.
+ -- We also use a renaming declaration for expressions of an array
+ -- type that is not bit-packed, both for efficiency reasons and to
+ -- respect the semantics of the call: in most cases the original
+ -- call will pass the parameter by reference, and thus the inlined
+ -- code will have the same semantics.
+
if Ekind (F) = E_In_Parameter
and then not Is_Limited_Type (Etype (A))
and then not Is_Tagged_Type (Etype (A))
+ and then
+ (not Is_Array_Type (Etype (A))
+ or else not Is_Object_Reference (A)
+ or else Is_Bit_Packed_Array (Etype (A)))
then
Decl :=
Make_Object_Declaration (Loc,
Set_Is_Internal (Temp);
-- For the unconstrained case, the generated temporary has the
- -- same constrained declaration as the result variable.
- -- It may eventually be possible to remove that temporary and
- -- use the result variable directly.
+ -- same constrained declaration as the result variable. It may
+ -- eventually be possible to remove that temporary and use the
+ -- result variable directly.
if Is_Unc then
Decl :=
end if;
-- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
- -- conflicting private views that Gigi would ignore. If this is
+ -- conflicting private views that Gigi would ignore. If this is a
-- predefined unit, analyze with checks off, as is done in the non-
-- inlined run-time units.
begin
Expand_Call (N);
- -- If the return value of a foreign compiled function is
- -- VAX Float then expand the return (adjusts the location
- -- of the return value on Alpha/VMS, noop everywhere else).
+ -- If the return value of a foreign compiled function is VAX Float, then
+ -- expand the return (adjusts the location of the return value on
+ -- Alpha/VMS, no-op everywhere else).
-- Comes_From_Source intercepts recursive expansion.
if Vax_Float (Etype (N))
-- Expand_N_Subprogram_Body --
------------------------------
- -- Add poll call if ATC polling is enabled, unless the body will be
- -- inlined by the back-end.
+ -- Add poll call if ATC polling is enabled, unless the body will be inlined
+ -- by the back-end.
-- Add dummy push/pop label nodes at start and end to clear any local
- -- exception indications if local-exception-to-goto optimization active.
+ -- exception indications if local-exception-to-goto optimization is active.
-- Add return statement if last statement in body is not a return statement
-- (this makes things easier on Gigi which does not want to have to handle
procedure Add_Return (S : List_Id);
-- Append a return statement to the statement sequence S if the last
-- statement is not already a return or a goto statement. Note that
- -- the latter test is not critical, it does not matter if we add a
- -- few extra returns, since they get eliminated anyway later on.
+ -- the latter test is not critical, it does not matter if we add a few
+ -- extra returns, since they get eliminated anyway later on.
----------------
-- Add_Return --
Loc := Sloc (Last_Stm);
end if;
- Append_To (S, Make_Simple_Return_Statement (Loc));
+ declare
+ Rtn : constant Node_Id := Make_Simple_Return_Statement (Loc);
+
+ begin
+ -- Append return statement, and set analyzed manually. We can't
+ -- call Analyze on this return since the scope is wrong.
+
+ -- Note: it almost works to push the scope and then do the
+ -- Analyze call, but something goes wrong in some weird cases
+ -- and it is not worth worrying about ???
+
+ Append_To (S, Rtn);
+ Set_Analyzed (Rtn);
+
+ -- Call _Postconditions procedure if appropriate. We need to
+ -- do this explicitly because we did not analyze the generated
+ -- return statement above, so the call did not get inserted.
+
+ if Ekind (Spec_Id) = E_Procedure
+ and then Has_Postconditions (Spec_Id)
+ then
+ pragma Assert (Present (Postcondition_Proc (Spec_Id)));
+ Insert_Action (Rtn,
+ Make_Procedure_Call_Statement (Loc,
+ Name =>
+ New_Reference_To (Postcondition_Proc (Spec_Id), Loc)));
+ end if;
+ end;
end if;
end Add_Return;
-- Start of processing for Expand_N_Subprogram_Body
begin
- -- Set L to either the list of declarations if present, or
- -- to the list of statements if no declarations are present.
- -- This is used to insert new stuff at the start.
+ -- Set L to either the list of declarations if present, or to the list
+ -- of statements if no declarations are present. This is used to insert
+ -- new stuff at the start.
if Is_Non_Empty_List (Declarations (N)) then
L := Declarations (N);
-- Need poll on entry to subprogram if polling enabled. We only do this
-- for non-empty subprograms, since it does not seem necessary to poll
- -- for a dummy null subprogram. Do not add polling point if calls to
- -- this subprogram will be inlined by the back-end, to avoid repeated
- -- polling points in nested inlinings.
+ -- for a dummy null subprogram.
if Is_Non_Empty_List (L) then
+
+ -- Do not add a polling call if the subprogram is to be inlined by
+ -- the back-end, to avoid repeated calls with multiple inlinings.
+
if Is_Inlined (Spec_Id)
and then Front_End_Inlining
and then Optimization_Level > 1
end if;
end if;
- -- If this is a Pure function which has any parameters whose root
- -- type is System.Address, reset the Pure indication, since it will
- -- likely cause incorrect code to be generated as the parameter is
- -- probably a pointer, and the fact that the same pointer is passed
- -- does not mean that the same value is being referenced.
+ -- If this is a Pure function which has any parameters whose root type
+ -- is System.Address, reset the Pure indication, since it will likely
+ -- cause incorrect code to be generated as the parameter is probably
+ -- a pointer, and the fact that the same pointer is passed does not mean
+ -- that the same value is being referenced.
-- Note that if the programmer gave an explicit Pure_Function pragma,
-- then we believe the programmer, and leave the subprogram Pure.
- -- This code should probably be at the freeze point, so that it
- -- happens even on a -gnatc (or more importantly -gnatt) compile
- -- so that the semantic tree has Is_Pure set properly ???
+ -- This code should probably be at the freeze point, so that it happens
+ -- even on a -gnatc (or more importantly -gnatt) compile, so that the
+ -- semantic tree has Is_Pure set properly ???
if Is_Pure (Spec_Id)
and then Is_Subprogram (Spec_Id)
Set_Discriminals (Parent (Base_Type (Scope (Spec_Id))));
end if;
- -- Returns_By_Ref flag is normally set when the subprogram is frozen
- -- but subprograms with no specs are not frozen.
+ -- Returns_By_Ref flag is normally set when the subprogram is frozen but
+ -- subprograms with no specs are not frozen.
declare
Typ : constant Entity_Id := Etype (Spec_Id);
elsif Is_Inherently_Limited_Type (Typ) then
Set_Returns_By_Ref (Spec_Id);
- elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
+ elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
Set_Returns_By_Ref (Spec_Id);
end if;
end;
- -- For a procedure, we add a return for all possible syntactic ends
- -- of the subprogram. Note that reanalysis is not necessary in this
- -- case since it would require a lot of work and accomplish nothing.
+ -- For a procedure, we add a return for all possible syntactic ends of
+ -- the subprogram.
if Ekind (Spec_Id) = E_Procedure
or else Ekind (Spec_Id) = E_Generic_Procedure
-- raise Program_Error;
-- end;
- -- This approach is necessary because the raise must be signalled
- -- to the caller, not handled by any local handler (RM 6.4(11)).
+ -- This approach is necessary because the raise must be signalled to the
+ -- caller, not handled by any local handler (RM 6.4(11)).
- -- Note: we do not need to analyze the constructed sequence here,
- -- since it has no handler, and an attempt to analyze the handled
- -- statement sequence twice is risky in various ways (e.g. the
- -- issue of expanding cleanup actions twice).
+ -- Note: we do not need to analyze the constructed sequence here, since
+ -- it has no handler, and an attempt to analyze the handled statement
+ -- sequence twice is risky in various ways (e.g. the issue of expanding
+ -- cleanup actions twice).
elsif Has_Missing_Return (Spec_Id) then
declare
Analyze (Prot_Decl);
Insert_Actions (N, Freeze_Entity (Prot_Id, Loc));
Set_Protected_Body_Subprogram (Subp, Prot_Id);
+
+ -- Create protected operation as well. Even though the operation
+ -- is only accessible within the body, it is possible to make it
+ -- available outside of the protected object by using 'Access to
+ -- provide a callback, so build protected version in all cases.
+
+ Prot_Decl :=
+ Make_Subprogram_Declaration (Loc,
+ Specification =>
+ Build_Protected_Sub_Specification (N, Scop, Protected_Mode));
+ Insert_Before (Prot_Bod, Prot_Decl);
+ Analyze (Prot_Decl);
+
Pop_Scope;
end if;
- -- Ada 2005 (AI-348): Generation of the null body
+ -- Ada 2005 (AI-348): Generate body for a null procedure.
+ -- In most cases this is superfluous because calls to it
+ -- will be automatically inlined, but we definitely need
+ -- the body if preconditions for the procedure are present.
elsif Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
then
declare
- Bod : constant Node_Id :=
- Make_Subprogram_Body (Loc,
- Specification =>
- New_Copy_Tree (Specification (N)),
- Declarations => New_List,
- Handled_Statement_Sequence =>
- Make_Handled_Sequence_Of_Statements (Loc,
- Statements => New_List (Make_Null_Statement (Loc))));
- begin
- Set_Body_To_Inline (N, Bod);
- Insert_After (N, Bod);
- Analyze (Bod);
+ Bod : constant Node_Id := Body_To_Inline (N);
- -- Corresponding_Spec isn't being set by Analyze_Subprogram_Body,
- -- evidently because Set_Has_Completion is called earlier for null
- -- procedures in Analyze_Subprogram_Declaration, so we force its
- -- setting here. If the setting of Has_Completion is not set
- -- earlier, then it can result in missing body errors if other
- -- errors were already reported (since expansion is turned off).
+ begin
+ Set_Has_Completion (Subp, False);
+ Append_Freeze_Action (Subp, Bod);
- -- Should creation of the empty body be moved to the analyzer???
+ -- The body now contains raise statements, so calls to it will
+ -- not be inlined.
- Set_Corresponding_Spec (Bod, Defining_Entity (Specification (N)));
+ Set_Is_Inlined (Subp, False);
end;
end if;
end Expand_N_Subprogram_Declaration;
-- which denotes the enclosing protected object. If the enclosing
-- operation is an entry, we are immediately within the protected body,
-- and we can retrieve the object from the service entries procedure. A
- -- barrier function has has the same signature as an entry. A barrier
+ -- barrier function has the same signature as an entry. A barrier
-- function is compiled within the protected object, but unlike
-- protected operations its never needs locks, so that its protected
-- body subprogram points to itself.
end if;
- Analyze (N);
-
-- If it is a function call it can appear in elaboration code and
-- the called entity must be frozen here.
if Ekind (Subp) = E_Function then
Freeze_Expression (Name (N));
end if;
+
+ -- Analyze and resolve the new call. The actuals have already been
+ -- resolved, but expansion of a function call will add extra actuals
+ -- if needed. Analysis of a procedure call already includes resolution.
+
+ Analyze (N);
+
+ if Ekind (Subp) = E_Function then
+ Resolve (N, Etype (Subp));
+ end if;
end Expand_Protected_Subprogram_Call;
--------------------------------
then
return False;
- -- If the return type is a limited interface it has to be treated
- -- as a return in place, even if the actual object is some non-
- -- limited descendant.
-
- elsif Is_Limited_Interface (Etype (E)) then
- return True;
+ -- In Ada 2005 all functions with an inherently limited return type
+ -- must be handled using a build-in-place profile, including the case
+ -- of a function with a limited interface result, where the function
+ -- may return objects of nonlimited descendants.
else
return Is_Inherently_Limited_Type (Etype (E))
end if;
end Is_Build_In_Place_Function_Call;
- ---------------------------------------
- -- Is_Build_In_Place_Function_Return --
- ---------------------------------------
-
- function Is_Build_In_Place_Function_Return (N : Node_Id) return Boolean is
- begin
- if Nkind_In (N, N_Simple_Return_Statement,
- N_Extended_Return_Statement)
- then
- return Is_Build_In_Place_Function
- (Return_Applies_To (Return_Statement_Entity (N)));
- else
- return False;
- end if;
- end Is_Build_In_Place_Function_Return;
-
-----------------------
-- Freeze_Subprogram --
-----------------------
and then not Is_Abstract_Subprogram (Subp)
and then Present (DTC_Entity (Subp))
and then Present (Scope (DTC_Entity (Subp)))
- and then VM_Target = No_VM
+ and then Tagged_Type_Expansion
and then not Restriction_Active (No_Dispatching_Calls)
and then RTE_Available (RE_Tag)
then
Register_Predefined_DT_Entry (Subp);
end if;
- Register_Primitive (Loc,
- Prim => Subp,
- Ins_Nod => N);
+ Insert_Actions_After (N,
+ Register_Primitive (Loc, Prim => Subp));
end if;
end if;
end;
begin
if Is_Inherently_Limited_Type (Typ) then
Set_Returns_By_Ref (Subp);
- elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
+ elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
Set_Returns_By_Ref (Subp);
end if;
end;
end Freeze_Subprogram;
+ -----------------------
+ -- Is_Null_Procedure --
+ -----------------------
+
+ function Is_Null_Procedure (Subp : Entity_Id) return Boolean is
+ Decl : constant Node_Id := Unit_Declaration_Node (Subp);
+
+ begin
+ if Ekind (Subp) /= E_Procedure then
+ return False;
+
+ -- Check if this is a declared null procedure
+
+ elsif Nkind (Decl) = N_Subprogram_Declaration then
+ if not Null_Present (Specification (Decl)) then
+ return False;
+
+ elsif No (Body_To_Inline (Decl)) then
+ return False;
+
+ -- Check if the body contains only a null statement, followed by
+ -- the return statement added during expansion.
+
+ else
+ declare
+ Orig_Bod : constant Node_Id := Body_To_Inline (Decl);
+
+ Stat : Node_Id;
+ Stat2 : Node_Id;
+
+ begin
+ if Nkind (Orig_Bod) /= N_Subprogram_Body then
+ return False;
+ else
+ -- We must skip SCIL nodes because they are currently
+ -- implemented as special N_Null_Statement nodes.
+
+ Stat :=
+ First_Non_SCIL_Node
+ (Statements (Handled_Statement_Sequence (Orig_Bod)));
+ Stat2 := Next_Non_SCIL_Node (Stat);
+
+ return
+ Is_Empty_List (Declarations (Orig_Bod))
+ and then Nkind (Stat) = N_Null_Statement
+ and then
+ (No (Stat2)
+ or else
+ (Nkind (Stat2) = N_Simple_Return_Statement
+ and then No (Next (Stat2))));
+ end if;
+ end;
+ end if;
+
+ else
+ return False;
+ end if;
+ end Is_Null_Procedure;
+
-------------------------------------------
-- Make_Build_In_Place_Call_In_Allocator --
-------------------------------------------
-- is handled separately further below.
New_Allocator :=
- Make_Allocator (Loc, New_Reference_To (Result_Subt, Loc));
+ Make_Allocator (Loc,
+ Expression => New_Reference_To (Result_Subt, Loc));
+ Set_No_Initialization (New_Allocator);
+
+ -- Copy attributes to new allocator. Note that the new allocator
+ -- logically comes from source if the original one did, so copy the
+ -- relevant flag. This ensures proper treatment of the restriction
+ -- No_Implicit_Heap_Allocations in this case.
- Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
+ Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
- Set_No_Initialization (New_Allocator);
+ Set_Comes_From_Source (New_Allocator, Comes_From_Source (Allocator));
Rewrite (Allocator, New_Allocator);
(Assign : Node_Id;
Function_Call : Node_Id)
is
- Lhs : constant Node_Id := Name (Assign);
- Loc : Source_Ptr;
- Func_Call : Node_Id := Function_Call;
- Function_Id : Entity_Id;
- Result_Subt : Entity_Id;
- Ref_Type : Entity_Id;
- Ptr_Typ_Decl : Node_Id;
- Def_Id : Entity_Id;
- New_Expr : Node_Id;
+ Lhs : constant Node_Id := Name (Assign);
+ Func_Call : Node_Id := Function_Call;
+ Func_Id : Entity_Id;
+ Loc : Source_Ptr;
+ Obj_Decl : Node_Id;
+ Obj_Id : Entity_Id;
+ Ptr_Typ : Entity_Id;
+ Ptr_Typ_Decl : Node_Id;
+ Result_Subt : Entity_Id;
+ Target : Node_Id;
begin
-- Step past qualification or unchecked conversion (the latter can occur
Loc := Sloc (Function_Call);
if Is_Entity_Name (Name (Func_Call)) then
- Function_Id := Entity (Name (Func_Call));
+ Func_Id := Entity (Name (Func_Call));
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
- Function_Id := Etype (Name (Func_Call));
+ Func_Id := Etype (Name (Func_Call));
else
raise Program_Error;
end if;
- Result_Subt := Etype (Function_Id);
+ Result_Subt := Etype (Func_Id);
-- When the result subtype is unconstrained, an additional actual must
-- be passed to indicate that the caller is providing the return object.
-- to be treated effectively the same as calls to class-wide functions.
Add_Alloc_Form_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
+ (Func_Call, Func_Id, Alloc_Form => Caller_Allocation);
-- If Lhs is a selected component, then pass it along so that its prefix
-- object will be used as the source of the finalization list.
if Nkind (Lhs) = N_Selected_Component then
Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Acc_Type => Empty, Sel_Comp => Lhs);
+ (Func_Call, Func_Id, Acc_Type => Empty, Sel_Comp => Lhs);
else
Add_Final_List_Actual_To_Build_In_Place_Call
- (Func_Call, Function_Id, Acc_Type => Empty);
+ (Func_Call, Func_Id, Acc_Type => Empty);
end if;
Add_Task_Actuals_To_Build_In_Place_Call
- (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
+ (Func_Call, Func_Id, Make_Identifier (Loc, Name_uMaster));
-- Add an implicit actual to the function call that provides access to
-- the caller's return object.
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call,
- Function_Id,
+ Func_Id,
Make_Unchecked_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Result_Subt, Loc),
Expression => Relocate_Node (Lhs)));
-- Create an access type designating the function's result subtype
- Ref_Type :=
+ Ptr_Typ :=
Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Ptr_Typ_Decl :=
Make_Full_Type_Declaration (Loc,
- Defining_Identifier => Ref_Type,
+ Defining_Identifier => Ptr_Typ,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication =>
New_Reference_To (Result_Subt, Loc)));
-
Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
-- Finally, create an access object initialized to a reference to the
-- function call.
- Def_Id :=
- Make_Defining_Identifier (Loc,
- Chars => New_Internal_Name ('R'));
- Set_Etype (Def_Id, Ref_Type);
+ Obj_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
+ Set_Etype (Obj_Id, Ptr_Typ);
- New_Expr :=
- Make_Reference (Loc,
- Prefix => Relocate_Node (Func_Call));
-
- Insert_After_And_Analyze (Ptr_Typ_Decl,
+ Obj_Decl :=
Make_Object_Declaration (Loc,
- Defining_Identifier => Def_Id,
- Object_Definition => New_Reference_To (Ref_Type, Loc),
- Expression => New_Expr));
+ Defining_Identifier => Obj_Id,
+ Object_Definition =>
+ New_Reference_To (Ptr_Typ, Loc),
+ Expression =>
+ Make_Reference (Loc,
+ Prefix => Relocate_Node (Func_Call)));
+ Insert_After_And_Analyze (Ptr_Typ_Decl, Obj_Decl);
Rewrite (Assign, Make_Null_Statement (Loc));
+
+ -- Retrieve the target of the assignment
+
+ if Nkind (Lhs) = N_Selected_Component then
+ Target := Selector_Name (Lhs);
+ elsif Nkind (Lhs) = N_Type_Conversion then
+ Target := Expression (Lhs);
+ else
+ Target := Lhs;
+ end if;
+
+ -- If we are assigning to a return object or this is an expression of
+ -- an extension aggregate, the target should either be an identifier
+ -- or a simple expression. All other cases imply a different scenario.
+
+ if Nkind (Target) in N_Has_Entity then
+ Target := Entity (Target);
+ else
+ return;
+ end if;
+
+ -- When the target of the assignment is a return object of an enclosing
+ -- build-in-place function and also requires finalization, the list
+ -- generated for the assignment must be moved to that of the enclosing
+ -- function.
+
+ -- function Enclosing_BIP_Function return Ctrl_Typ is
+ -- begin
+ -- return (Ctrl_Parent_Part => BIP_Function with ...);
+ -- end Enclosing_BIP_Function;
+
+ if Is_Return_Object (Target)
+ and then Needs_Finalization (Etype (Target))
+ and then Needs_Finalization (Result_Subt)
+ then
+ declare
+ Obj_List : constant Node_Id := Find_Final_List (Obj_Id);
+ Encl_List : Node_Id;
+ Encl_Scop : Entity_Id;
+
+ begin
+ Encl_Scop := Scope (Target);
+
+ -- Locate the scope of the extended return statement
+
+ while Present (Encl_Scop)
+ and then Ekind (Encl_Scop) /= E_Return_Statement
+ loop
+ Encl_Scop := Scope (Encl_Scop);
+ end loop;
+
+ -- A return object should always be enclosed by a return statement
+ -- scope at some level.
+
+ pragma Assert (Present (Encl_Scop));
+
+ Encl_List :=
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Reference_To (
+ Finalization_Chain_Entity (Encl_Scop), Loc),
+ Attribute_Name => Name_Unrestricted_Access);
+
+ -- Generate a call to move final list
+
+ Insert_After_And_Analyze (Obj_Decl,
+ Make_Procedure_Call_Statement (Loc,
+ Name =>
+ New_Reference_To (RTE (RE_Move_Final_List), Loc),
+ Parameter_Associations => New_List (Obj_List, Encl_List)));
+ end;
+ end if;
end Make_Build_In_Place_Call_In_Assignment;
----------------------------------------------------
-- If the function's result subtype is unconstrained and the object is
-- a return object of an enclosing build-in-place function, then the
-- implicit build-in-place parameters of the enclosing function must be
- -- passed along to the called function.
-
- elsif Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement then
+ -- passed along to the called function. (Unfortunately, this won't cover
+ -- the case of extension aggregates where the ancestor part is a build-
+ -- in-place unconstrained function call that should be passed along the
+ -- caller's parameters. Currently those get mishandled by reassigning
+ -- the result of the call to the aggregate return object, when the call
+ -- result should really be directly built in place in the aggregate and
+ -- not built in a temporary. ???)
+
+ elsif Is_Return_Object (Defining_Identifier (Object_Decl)) then
Pass_Caller_Acc := True;
Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
-- in current scope). The Next_Entity links of the two entities also
-- have to be swapped since the entities are part of the return
-- scope's entity list and the list structure would otherwise be
- -- corrupted.
+ -- corrupted. Finally, the homonym chain must be preserved as well.
declare
Renaming_Def_Id : constant Entity_Id :=
Set_Next_Entity (Renaming_Def_Id, Next_Entity (Obj_Def_Id));
Set_Next_Entity (Obj_Def_Id, Next_Entity_Temp);
+ Set_Homonym (Renaming_Def_Id, Homonym (Obj_Def_Id));
Exchange_Entities (Renaming_Def_Id, Obj_Def_Id);
end;
end if;
end Make_Build_In_Place_Call_In_Object_Declaration;
+ --------------------------
+ -- Needs_BIP_Final_List --
+ --------------------------
+
+ function Needs_BIP_Final_List (E : Entity_Id) return Boolean is
+ pragma Assert (Is_Build_In_Place_Function (E));
+ Result_Subt : constant Entity_Id := Underlying_Type (Etype (E));
+
+ begin
+ -- We need the BIP_Final_List if the result type needs finalization. We
+ -- also need it for tagged types, even if not class-wide, because some
+ -- type extension might need finalization, and all overriding functions
+ -- must have the same calling conventions. However, if there is a
+ -- pragma Restrictions (No_Finalization), we never need this parameter.
+
+ return (Needs_Finalization (Result_Subt)
+ or else Is_Tagged_Type (Underlying_Type (Result_Subt)))
+ and then not Restriction_Active (No_Finalization);
+ end Needs_BIP_Final_List;
+
end Exp_Ch6;
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