commit b1eda10e17bf2056ca79a534d92fe0b0b06bd410
Author: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue Nov 25 14:12:48 2014 -0800
fnmatch: work around GCC compiler warning bug with uninit var
* posix/fnmatch_loop.c (FCT): Use a scalar not a one-item array.
This works around a bug with x86-64 GCC 4.9.2 and earlier
where 'gcc -O2 -Wmaybe-uninitialized' incorrectly complains
"../locale/weightwc.h:93:7: warning: '*((void *)&str+4)' may be
used uninitialized in this function [-Wmaybe-uninitialized]".
diff --git a/posix/fnmatch_loop.c b/posix/fnmatch_loop.c
index e289f451cc23c1ee..2bd788f3942c6e7d 100644
--- a/posix/fnmatch_loop.c
+++ b/posix/fnmatch_loop.c
@@ -342,7 +342,12 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends, alloca_used)
#ifdef _LIBC
else if (c == L('[') && *p == L('='))
{
- UCHAR str[1];
+ /* It's important that STR be a scalar variable rather
+ than a one-element array, because GCC (at least 4.9.2
+ -O2 on x86-64) can be confused by the array and
+ diagnose a "used initialized" in a dead branch in the
+ findidx function. */
+ UCHAR str;
uint32_t nrules =
_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
const CHAR *startp = p;
@@ -354,7 +359,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends, alloca_used)
c = L('[');
goto normal_bracket;
}
- str[0] = c;
+ str = c;
c = *++p;
if (c != L('=') || p[1] != L(']'))
@@ -367,7 +372,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends, alloca_used)
if (nrules == 0)
{
- if ((UCHAR) *n == str[0])
+ if ((UCHAR) *n == str)
goto matched;
}
else
@@ -382,7 +387,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends, alloca_used)
# endif
const int32_t *indirect;
int32_t idx;
- const UCHAR *cp = (const UCHAR *) str;
+ const UCHAR *cp = (const UCHAR *) &str;
/* This #include defines a local function! */
# if WIDE_CHAR_VERSION