commit b1eda10e17bf2056ca79a534d92fe0b0b06bd410 Author: Paul Eggert 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