libgcc: Avoid warnings on __gcc_nested_func_ptr_created [PR113402]

I'm seeing hundreds of
In file included from ../../../libgcc/libgcc2.c:56:
../../../libgcc/libgcc2.h:32:13: warning: conflicting types for built-in function ‘__gcc_nested_func_ptr_created’; expected ‘void(void *, void *, void *)’
+[-Wbuiltin-declaration-mismatch]
   32 | extern void __gcc_nested_func_ptr_created (void *, void *, void **);
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
warnings.

Either we need to add like in r14-6218
  #pragma GCC diagnostic ignored "-Wbuiltin-declaration-mismatch"
(but in that case because of the libgcc2.h prototype (why is it there?)
it would need to be also with #pragma GCC diagnostic push/pop around),
or we could go with just following how the builtins are prototyped on the
compiler side and only cast to void ** when dereferencing (which is in
a single spot in each TU).

2024-02-01  Jakub Jelinek  <jakub@redhat.com>

	PR libgcc/113402
	* libgcc2.h (__gcc_nested_func_ptr_created): Change type of last
	argument from void ** to void *.
	* config/i386/heap-trampoline.c (__gcc_nested_func_ptr_created):
	Change type of dst from void ** to void * and cast dst to void **
	before dereferencing it.
	* config/aarch64/heap-trampoline.c (__gcc_nested_func_ptr_created):
	Likewise.

3 files changed, 7 insertions, 7 deletions

diff --git a/libgcc/config/aarch64/heap-trampoline.c b/libgcc/config/aarch64/heap-trampoline.c
index b463399..9d5b199 100644
--- a/libgcc/config/aarch64/heap-trampoline.c
+++ b/libgcc/config/aarch64/heap-trampoline.c
@@ -26,7 +26,7 @@ int get_trampolines_per_page (void);
 struct tramp_ctrl_data *allocate_tramp_ctrl (struct tramp_ctrl_data *parent);
 void *allocate_trampoline_page (void);
 
-void __gcc_nested_func_ptr_created (void *chain, void *func, void **dst);
+void __gcc_nested_func_ptr_created (void *chain, void *func, void *dst);
 void __gcc_nested_func_ptr_deleted (void);
 
 #if defined(__gnu_linux__)
@@ -115,7 +115,7 @@ allocate_tramp_ctrl (struct tramp_ctrl_data *parent)
 
 HEAP_T_ATTR
 void
-__gcc_nested_func_ptr_created (void *chain, void *func, void **dst)
+__gcc_nested_func_ptr_created (void *chain, void *func, void *dst)
 {
   if (tramp_ctrl_curr == NULL)
     {
@@ -158,7 +158,7 @@ __gcc_nested_func_ptr_created (void *chain, void *func, void **dst)
   __builtin___clear_cache ((void *)trampoline->insns,
 			   ((void *)trampoline->insns + sizeof(trampoline->insns)));
 
-  *dst = &trampoline->insns;
+  *(void **) dst = &trampoline->insns;
 }
 
 HEAP_T_ATTR
diff --git a/libgcc/config/i386/heap-trampoline.c b/libgcc/config/i386/heap-trampoline.c
index 4e069c4..657b344 100644
--- a/libgcc/config/i386/heap-trampoline.c
+++ b/libgcc/config/i386/heap-trampoline.c
@@ -26,7 +26,7 @@ int get_trampolines_per_page (void);
 struct tramp_ctrl_data *allocate_tramp_ctrl (struct tramp_ctrl_data *parent);
 void *allocate_trampoline_page (void);
 
-void __gcc_nested_func_ptr_created (void *chain, void *func, void **dst);
+void __gcc_nested_func_ptr_created (void *chain, void *func, void *dst);
 void __gcc_nested_func_ptr_deleted (void);
 
 static const uint8_t trampoline_insns[] = {
@@ -115,7 +115,7 @@ allocate_tramp_ctrl (struct tramp_ctrl_data *parent)
 
 HEAP_T_ATTR
 void
-__gcc_nested_func_ptr_created (void *chain, void *func, void **dst)
+__gcc_nested_func_ptr_created (void *chain, void *func, void *dst)
 {
   if (tramp_ctrl_curr == NULL)
     {
@@ -158,7 +158,7 @@ __gcc_nested_func_ptr_created (void *chain, void *func, void **dst)
   __builtin___clear_cache ((void *)trampoline->insns,
 			   ((void *)trampoline->insns + sizeof(trampoline->insns)));
 
-  *dst = &trampoline->insns;
+  *(void **) dst = &trampoline->insns;
 }
 
 HEAP_T_ATTR
diff --git a/libgcc/libgcc2.h b/libgcc/libgcc2.h
index 0b67fab..b358b3a 100644
--- a/libgcc/libgcc2.h
+++ b/libgcc/libgcc2.h
@@ -29,7 +29,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #pragma GCC visibility push(default)
 #endif
 
-extern void __gcc_nested_func_ptr_created (void *, void *, void **);
+extern void __gcc_nested_func_ptr_created (void *, void *, void *);
 extern void __gcc_nested_func_ptr_deleted (void);
 
 extern int __gcc_bcmp (const unsigned char *, const unsigned char *, size_t);