diff options
Diffstat (limited to 'gcc/ada/decl.c')
| -rw-r--r-- | gcc/ada/decl.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/ada/decl.c b/gcc/ada/decl.c index dbd7970..ff2927f 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) |