@@ -60,27 +60,20 @@
#define Has_Stdcall_Convention(E) (0)
-/* 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.
+/* Stack realignment is necessary for functions with foreign conventions when
+ the ABI doesn't mandate as much as what the compiler assumes - that is, up
+ to PREFERRED_STACK_BOUNDARY.
- 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.
+ Such realignment can be requested with a dedicated function type attribute
+ on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to
+ characterize the situations where the attribute should be set. We rely on
+ compiler configuration settings for 'main' to decide. */
- 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. */
-#define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN 0
+#define FOREIGN_FORCE_REALIGN_STACK \
+ (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY)
+#define FOREIGN_FORCE_REALIGN_STACK 0
@@ -4208,13 +4201,10 @@
get_identifier ("stdcall"), NULL_TREE,
- /* 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
+ /* If we should request stack realignment for a foreign convention
+ subprogram, do so. Note that this applies to task entry points in
+ particular. */
+ if (FOREIGN_FORCE_REALIGN_STACK
&& Has_Foreign_Convention (gnat_entity))