cleanup and work around visibility bug in gcc 3 that affects x86_64

in gcc 3, the visibility attribute must be placed on both the
declaration and on the definition. if it's omitted from the
definition, the compiler fails to emit the ".hidden" directive in the
assembly, and the linker will either generate textrels (if supported,
such as on i386) or refuse to link (on targets where certain types of
textrels are forbidden or impossible without further assumptions about
memory layout, such as on x86_64).

this patch also unifies the decision about when to use visibility into
libc.h and makes the visibility in the utf-8 state machine tables
based on libc.h rather than a duplicate test.

1 files changed, 3 insertions, 5 deletions

diff --git a/src/multibyte/internal.h b/src/multibyte/internal.h
index df47331e..cd1196ba 100644
--- a/src/multibyte/internal.h
+++ b/src/multibyte/internal.h
@@ -6,11 +6,9 @@
 
 #define bittab __fsmu8
 
-#if 100*__GNUC__+__GNUC_MINOR__ >= 303 || defined(__PCC__) || defined(__TINYC__)
-extern const uint32_t bittab[] __attribute__((visibility("hidden")));
-#else
-extern const uint32_t bittab[];
-#endif
+#include "libc.h"
+
+extern const uint32_t bittab[] ATTR_LIBC_VISIBILITY;
 
 /* Upper 6 state bits are a negative integer offset to bound-check next byte */
 /*    equivalent to: ( (b-0x80) | (b+offset) ) & ~0x3f      */