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riscv-gcc-1
Commit a40d9947 by Patrick Bernardi Committed by Pierre-Marie de Rodat
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[Ada] Aspect/pragma Secondary_Stack_Size can evaluate non-literals as zero 

This patch fixes the problem of aspect/pragma Secondary_Stack_Size expressions
with non-literals evaluating as zero in static secondary stacks allocations.
The aspect Secondary_Stack_Size is now converted to a pragma instead of an
attribute as the attribute does not have visibility on the discriminant.
Additionally, the discriminant of the corresponding record type is now
referenced if the pragma expression contains a discriminant.

No simple test available as the problem only impacts programs when
System.Parameters.Sec_Stack_Dynamic = False

2018-01-11  Patrick Bernardi  <bernardi@adacore.com>

gcc/ada/

	* exp_ch9.adb (Expand_N_Task_Type_Declaration): Simplified
	Secondary_Stack_Size handling as a pragma is now generated for the
	corresponding aspect instead of an attribute.  Pragma expression is
	relocated instead of evaluated. Discriminant of the corresponding
	record type is referenced rather than the type discriminant.
	(Create_Secondary_Stack_For_Task, Make_Task_Create_Call): Update
	Secondary_Stack_Size rep item checks to only look for the pragma rep.
	* sem_ch13.adb (Analyze_One_Aspect): Transform
	Aspect_Secondary_Stack_Size into a pragma instead of an attribute
	because the attribute does not have visibility on a task type's
	discriminants when the type's definition is expanded.
	(Analyze_Attribute_Definition_Clause): Remove handling of
	Attribute_Secondary_Stack_Size.
	* snames.adb-tmpl, snames.ads-tmpl: Remove
	Attribute_Secondary_Stack_Size, no longer used.

From-SVN: r256488
parent 6b199a18
Showing with 74 additions and 73 deletions
gcc/ada/ChangeLog
2018-01-11 Patrick Bernardi <bernardi@adacore.com>
* exp_ch9.adb (Expand_N_Task_Type_Declaration): Simplified
Secondary_Stack_Size handling as a pragma is now generated for the
corresponding aspect instead of an attribute. Pragma expression is
relocated instead of evaluated. Discriminant of the corresponding
record type is referenced rather than the type discriminant.
(Create_Secondary_Stack_For_Task, Make_Task_Create_Call): Update
Secondary_Stack_Size rep item checks to only look for the pragma rep.
* sem_ch13.adb (Analyze_One_Aspect): Transform
Aspect_Secondary_Stack_Size into a pragma instead of an attribute
because the attribute does not have visibility on a task type's
discriminants when the type's definition is expanded.
(Analyze_Attribute_Definition_Clause): Remove handling of
Attribute_Secondary_Stack_Size.
* snames.adb-tmpl, snames.ads-tmpl: Remove
Attribute_Secondary_Stack_Size, no longer used.
2018-01-11 Justin Squirek <squirek@adacore.com>
* sem_ch8.adb: Minor comment fix.
......
gcc/ada/exp_ch9.adb
......@@ -5437,7 +5437,7 @@ package body Exp_Ch9 is
(Restriction_Active (No_Implicit_Heap_Allocations)
or else Restriction_Active (No_Implicit_Task_Allocations))
and then not Restriction_Active (No_Secondary_Stack)
and then Has_Rep_Item
and then Has_Rep_Pragma
(T, Name_Secondary_Stack_Size, Check_Parents => False);
end Create_Secondary_Stack_For_Task;
......@@ -11933,7 +11933,7 @@ package body Exp_Ch9 is
Set_Analyzed (Task_Size);
else
Task_Size := Relocate_Node (Expr_N);
Task_Size := New_Copy_Tree (Expr_N);
end if;
end;
......@@ -11971,29 +11971,35 @@ package body Exp_Ch9 is
if Create_Secondary_Stack_For_Task (TaskId) then
declare
Ritem : Node_Id;
Size_Expr : Node_Id;
Stack_Size : Node_Id;
begin
-- First extract the secondary stack size from the task type's
-- representation aspect.
Size_Expr : constant Node_Id :=
Expression (First (
Pragma_Argument_Associations (
Get_Rep_Pragma (TaskId,
Name_Secondary_Stack_Size))));
Ritem :=
Get_Rep_Item
(TaskId, Name_Secondary_Stack_Size, Check_Parents => False);
begin
-- The secondary stack is defined inside the corresponding
-- record. Therefore if the size of the stack is set by means
-- of a discriminant, we must reference the discriminant of the
-- corresponding record type.
-- Get Secondary_Stack_Size expression. Can be a pragma or aspect.
if Nkind (Size_Expr) in N_Has_Entity
and then Present (Discriminal_Link (Entity (Size_Expr)))
then
Stack_Size :=
New_Occurrence_Of
(CR_Discriminant (Discriminal_Link (Entity (Size_Expr))),
Loc);
Set_Parent (Stack_Size, Parent (Size_Expr));
Set_Etype (Stack_Size, Etype (Size_Expr));
Set_Analyzed (Stack_Size);
if Nkind (Ritem) = N_Pragma then
Size_Expr :=
Expression
(First (Pragma_Argument_Associations (Ritem)));
else
Size_Expr := Expression (Ritem);
Stack_Size := New_Copy_Tree (Size_Expr);
end if;
pragma Assert (Compile_Time_Known_Value (Size_Expr));
-- Create the secondary stack for the task
Decl_SS :=
......@@ -12010,8 +12016,8 @@ package body Exp_Ch9 is
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Integer_Literal (Loc,
Expr_Value (Size_Expr)))))));
Convert_To (RTE (RE_Size_Type),
Stack_Size))))));
Append_To (Cdecls, Decl_SS);
end;
......@@ -12052,16 +12058,16 @@ package body Exp_Ch9 is
Expression =>
Convert_To (RTE (RE_Size_Type),
Relocate_Node (
New_Copy_Tree (
Expression (First (
Pragma_Argument_Associations (
Get_Rep_Pragma (TaskId, Name_Storage_Size))))))));
end if;
-- Add the _Secondary_Stack_Size component if a Secondary_Stack_Size
-- rep item is present.
-- pragma is present.
if Has_Rep_Item
if Has_Rep_Pragma
(TaskId, Name_Secondary_Stack_Size, Check_Parents => False)
then
Append_To (Cdecls,
......@@ -12135,7 +12141,7 @@ package body Exp_Ch9 is
Expression =>
Convert_To (RTE (RE_Time_Span),
Relocate_Node (
New_Copy_Tree (
Expression (First (
Pragma_Argument_Associations (
Get_Relative_Deadline_Pragma (Taskdef))))))));
......@@ -14246,15 +14252,15 @@ package body Exp_Ch9 is
end if;
-- Secondary_Stack_Size parameter. Set RE_Unspecified_Size unless there
-- is a Secondary_Stack_Size rep item, in which case take the value from
-- the rep item. If the restriction No_Secondary_Stack is active then a
-- is a Secondary_Stack_Size pragma, in which case take the value from
-- the pragma. If the restriction No_Secondary_Stack is active then a
-- size of 0 is passed regardless to prevent the allocation of the
-- unused stack.
if Restriction_Active (No_Secondary_Stack) then
Append_To (Args, Make_Integer_Literal (Loc, 0));
elsif Has_Rep_Item
elsif Has_Rep_Pragma
(Ttyp, Name_Secondary_Stack_Size, Check_Parents => False)
then
Append_To (Args,
......
gcc/ada/sem_ch13.adb
......@@ -2210,7 +2210,6 @@ package body Sem_Ch13 is
| Aspect_Output
| Aspect_Read
| Aspect_Scalar_Storage_Order
| Aspect_Secondary_Stack_Size
| Aspect_Simple_Storage_Pool
| Aspect_Size
| Aspect_Small
......@@ -3205,6 +3204,27 @@ package body Sem_Ch13 is
end;
end if;
-- Secondary_Stack_Size
-- Aspect Secondary_Stack_Size needs to be converted into a
-- pragma for two reasons: the attribute is not analyzed until
-- after the expansion of the task type declaration and the
-- attribute does not have visibility on the discriminant.
when Aspect_Secondary_Stack_Size =>
Make_Aitem_Pragma
(Pragma_Argument_Associations => New_List (
Make_Pragma_Argument_Association (Loc,
Expression => Relocate_Node (Expr))),
Pragma_Name =>
Name_Secondary_Stack_Size);
Decorate (Aspect, Aitem);
Insert_Pragma (Aitem);
goto Continue;
-- Volatile_Function
-- Aspect Volatile_Function is never delayed because it is
-- equivalent to a source pragma which appears after the
-- related subprogram.
......@@ -5851,46 +5871,6 @@ package body Sem_Ch13 is
Set_SSO_Set_High_By_Default (Base_Type (U_Ent), False);
end if;
--------------------------
-- Secondary_Stack_Size --
--------------------------
when Attribute_Secondary_Stack_Size =>
-- Secondary_Stack_Size attribute definition clause not allowed
-- except from aspect specification.
if From_Aspect_Specification (N) then
if not Is_Task_Type (U_Ent) then
Error_Msg_N
("Secondary Stack Size can only be defined for task", Nam);
elsif Duplicate_Clause then
null;
else
Check_Restriction (No_Secondary_Stack, Expr);
-- The expression must be analyzed in the special manner
-- described in "Handling of Default and Per-Object
-- Expressions" in sem.ads.
-- The visibility to the discriminants must be restored
Push_Scope_And_Install_Discriminants (U_Ent);
Preanalyze_Spec_Expression (Expr, Any_Integer);
Uninstall_Discriminants_And_Pop_Scope (U_Ent);
if not Is_OK_Static_Expression (Expr) then
Check_Restriction (Static_Storage_Size, Expr);
end if;
end if;
else
Error_Msg_N
("attribute& cannot be set with definition clause", N);
end if;
----------
-- Size --
----------
......
gcc/ada/snames.adb-tmpl
......@@ -134,8 +134,6 @@ package body Snames is
return Attribute_Dispatching_Domain;
elsif N = Name_Interrupt_Priority then
return Attribute_Interrupt_Priority;
elsif N = Name_Secondary_Stack_Size then
return Attribute_Secondary_Stack_Size;
else
return Attribute_Id'Val (N - First_Attribute_Name);
end if;
......
gcc/ada/snames.ads-tmpl
......@@ -1706,11 +1706,10 @@ package Snames is
Attribute_CPU,
Attribute_Dispatching_Domain,
Attribute_Interrupt_Priority,
Attribute_Secondary_Stack_Size);
Attribute_Interrupt_Priority);
subtype Internal_Attribute_Id is Attribute_Id range
Attribute_CPU .. Attribute_Secondary_Stack_Size;
Attribute_CPU .. Attribute_Interrupt_Priority;
type Attribute_Class_Array is array (Attribute_Id) of Boolean;
-- Type used to build attribute classification flag arrays
......
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