Implement snprintf() and sprintf() using __builtin_va_arg_pack()

Requires at least GCC 4.3.

1 files changed, 28 insertions, 21 deletions

diff --git a/include/stdio.h b/include/stdio.h
index f157038..f87bd59 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -84,28 +84,35 @@ int vsprintf(char *s, const char *fmt, __builtin_va_list ap)
         return r;
 }
 
-#undef snprintf
-#define snprintf(s, n, fmt, ...) ({ \
-        size_t _n = n; \
-        size_t bos = __builtin_object_size(s, 0); \
-        if (_n > bos) \
-                __builtin_trap(); \
-        (snprintf)(s, _n, fmt, ## __VA_ARGS__); \
-})
+extern int __snprintf_orig(char *, size_t, const char *, ...)
+        __asm__(__USER_LABEL_PREFIX__ "snprintf");
+extern __inline __attribute__((__always_inline__,__gnu_inline__))
+int snprintf(char *s, size_t n, const char *fmt, ...)
+{
+        size_t bos = __builtin_object_size(s, 0);
 
-#undef sprintf
-#define sprintf(s, fmt, ...) ({ \
-        size_t bos = __builtin_object_size(s, 0); \
-        int r; \
-        if (bos != (size_t)-1) { \
-                r = (snprintf)(s, bos, fmt, ## __VA_ARGS__); \
-                if (r != -1 && (size_t)r >= bos) \
-                        __builtin_trap(); \
-        } else { \
-                r = (sprintf)(s, fmt, ## __VA_ARGS__); \
-        } \
-        r; \
-})
+        if (n > bos)
+                __builtin_trap();
+        return __snprintf_orig(s, n, fmt, __builtin_va_arg_pack());
+}
+
+extern int __sprintf_orig(char *, const char *, ...)
+        __asm__(__USER_LABEL_PREFIX__ "sprintf");
+extern __inline __attribute__((__always_inline__,__gnu_inline__))
+int sprintf(char *s, const char *fmt, ...)
+{
+        size_t bos = __builtin_object_size(s, 0);
+        int r;
+
+        if (bos != (size_t)-1) {
+                r = __snprintf_orig(s, bos, fmt, __builtin_va_arg_pack());
+                if (r != -1 && (size_t)r >= bos)
+                        __builtin_trap();
+        } else {
+                r = __sprintf_orig(s, fmt, __builtin_va_arg_pack());
+        }
+        return r;
+}
 
 #endif