Recent libgcc builds have been triggering -Wbuiltin-declaration-mismatch
due to the declaration of the __clear_cache built-in being incompatible
with how GCC declares it internally. The attached patch adjusts
the libgcc declaration and the one in the manual to match what GCC
expects.
Tested on x86_64-linux.
Martin
libgcc/ChangeLog:
* libgcc2.h (__clear_cache): Correct signature.
* libgcc2.c (__clear_cache): Same.
gcc/ChangeLog:
* doc/extend.texi (__clear_cache): Correct signature.
gcc/testsuite/ChangeLog:
* gcc.dg/Wbuiltin-declaration-mismatch-12.c: New test.
Index: libgcc/libgcc2.h
===================================================================
--- libgcc/libgcc2.h (revision 268583)
+++ libgcc/libgcc2.h (working copy)
@@ -30,7 +30,7 @@ see the files COPYING3 and COPYING.RUNTIME respect
#endif
extern int __gcc_bcmp (const unsigned char *, const unsigned char *, size_t);
-extern void __clear_cache (char *, char *);
+extern void __clear_cache (void *, void *);
extern void __eprintf (const char *, const char *, unsigned int, const char *)
__attribute__ ((__noreturn__));
Index: libgcc/libgcc2.c
===================================================================
--- libgcc/libgcc2.c (revision 268583)
+++ libgcc/libgcc2.c (working copy)
@@ -2162,11 +2162,14 @@ __eprintf (const char *string, const char *express
/* Clear part of an instruction cache. */
void
-__clear_cache (char *beg __attribute__((__unused__)),
- char *end __attribute__((__unused__)))
+__clear_cache (void *beg __attribute__((__unused__)),
+ void *end __attribute__((__unused__)))
{
#ifdef CLEAR_INSN_CACHE
- CLEAR_INSN_CACHE (beg, end);
+ /* Cast the void* pointers to char* as some implementations
+ of the macro assume the pointers can be subtracted from
+ one another. */
+ CLEAR_INSN_CACHE ((char *) beg, (char *) end);
#endif /* CLEAR_INSN_CACHE */
}
Index: gcc/doc/extend.texi
===================================================================
--- gcc/doc/extend.texi (revision 268583)
+++ gcc/doc/extend.texi (working copy)
@@ -13073,7 +13073,7 @@ void foo (void)
@end deftypefn
-@deftypefn {Built-in Function} void __builtin___clear_cache (char *@var{begin}, char *@var{end})
+@deftypefn {Built-in Function} void __builtin___clear_cache (void *@var{begin}, void *@var{end})
This function is used to flush the processor's instruction cache for
the region of memory between @var{begin} inclusive and @var{end}
exclusive. Some targets require that the instruction cache be
Index: gcc/testsuite/gcc.dg/Wbuiltin-declaration-mismatch-12.c
===================================================================
--- gcc/testsuite/gcc.dg/Wbuiltin-declaration-mismatch-12.c (nonexistent)
+++ gcc/testsuite/gcc.dg/Wbuiltin-declaration-mismatch-12.c (working copy)
@@ -0,0 +1,8 @@
+/* Verify that declaring the __clear_cache and __builtin_prefetch
+ intrinsic functions with the wrong signature is diagnosed.
+ { dg-do compile }
+ { dg-options "-Wbuiltin-declaration-mismatch -Wextra" } */
+
+extern void __clear_cache (char*, char*); /* { dg-warning "mismatch in argument 1 type of built-in function .__clear_cache.; expected .void \\\*." } */
+
+void __builtin_prefetch (const char *, ...); /* { dg-warning "mismatch in argument 1 type of built-in function .__builtin_prefetch.; expected .const void \\\*." } */
