From: Olivier Hainque Date: Fri, 13 Jun 2008 22:07:28 +0000 (+0000) Subject: decl.c (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN): Define to 0 if undefined. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d8612af2ce55574685f370c438431d3c0881553f;p=gcc.git decl.c (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN): Define to 0 if undefined. 2008-06-13 Olivier Hainque ada/ * decl.c (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN): Define to 0 if undefined. (gnat_to_gnu_entity) : Request stack realignment with force_align_arg_pointer attribute on foreign convention subprograms if FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN. testsuite/ * gnat.dg/task_stack_align.adb: New test. From-SVN: r136768 --- diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog index f0eb327e43d..2ad33efe5cf 100644 --- a/gcc/ada/ChangeLog +++ b/gcc/ada/ChangeLog @@ -1,3 +1,11 @@ +2008-06-13 Olivier Hainque + + * decl.c (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN): Define to 0 + if undefined. + (gnat_to_gnu_entity) : Request stack + realignment with force_align_arg_pointer attribute on foreign + convention subprograms if FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN. + 2008-06-13 Olivier Hainque * utils.c (rest_of_record_type_compilation): When computing diff --git a/gcc/ada/decl.c b/gcc/ada/decl.c index dbd797089fa..ff2927fe642 100644 --- a/gcc/ada/decl.c +++ b/gcc/ada/decl.c @@ -67,6 +67,29 @@ #define Has_Stdcall_Convention(E) (0) #endif +/* Stack realignment for functions with foreign conventions is provided on a + per back-end basis now, as it is handled by the prologue expanders and not + as part of the function's body any more. It might be requested by way of a + dedicated function type attribute on the targets that support it. + + We need a way to avoid setting the attribute on the targets that don't + support it and use FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN for this purpose. + + It is defined on targets where the circuitry is available, and indicates + whether the realignment is needed for 'main'. We use this to decide for + foreign subprograms as well. + + It is not defined on targets where the circuitry is not implemented, and + we just never set the attribute in these cases. + + Whether it is defined on all targets that would need it in theory is + not entirely clear. We currently trust the base GCC settings for this + purpose. */ + +#ifndef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN +#define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN 0 +#endif + struct incomplete { struct incomplete *next; @@ -3951,6 +3974,19 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) get_identifier ("stdcall"), NULL_TREE, gnat_entity); + /* If we are on a target where stack realignment is needed for 'main' + to honor GCC's implicit expectations (stack alignment greater than + what the base ABI guarantees), ensure we do the same for foreign + convention subprograms as they might be used as callbacks from code + breaking such expectations. Note that this applies to task entry + points in particular. */ + if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN + && Has_Foreign_Convention (gnat_entity)) + prepend_one_attribute_to + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("force_align_arg_pointer"), NULL_TREE, + gnat_entity); + /* The lists have been built in reverse. */ gnu_param_list = nreverse (gnu_param_list); if (has_stub) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index dd044c2b2df..6ddf1ce49d2 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2008-06-13 Olivier Hainque + + * gnat.dg/task_stack_align.adb: New test. + 2008-06-13 Jerry DeLisle PR fortran/35863 diff --git a/gcc/testsuite/gnat.dg/task_stack_align.adb b/gcc/testsuite/gnat.dg/task_stack_align.adb new file mode 100644 index 00000000000..1151a913beb --- /dev/null +++ b/gcc/testsuite/gnat.dg/task_stack_align.adb @@ -0,0 +1,31 @@ +-- { dg-do run } + +with Ada.Text_IO; use Ada.Text_IO; +with System.Storage_Elements; use System.Storage_Elements; + +procedure Task_Stack_Align is + + type Align_Me is record + Value : Integer; + end record; + for Align_Me'Alignment use Standard'Maximum_Alignment; + + procedure Check_Local_Alignment_From (Context : String) is + Object : Align_Me; + begin + if To_Integer (Object'Address) mod Object'Alignment /= 0 then + Put_Line ("alignment check failed in " & Context); + end if; + end; + + task type T; + + task body T is + begin + Check_Local_Alignment_From ("task T"); + end; + + Tasks : array (1 .. 50) of T; +begin + Check_Local_Alignment_From ("environment"); +end;