diff options
Diffstat (limited to 'gl/m4/strstr.m4')
| -rw-r--r-- | gl/m4/strstr.m4 | 91 |
1 files changed, 71 insertions, 20 deletions
diff --git a/gl/m4/strstr.m4 b/gl/m4/strstr.m4 index 779957aa..c486bdb0 100644 --- a/gl/m4/strstr.m4 +++ b/gl/m4/strstr.m4 @@ -1,5 +1,5 @@ -# strstr.m4 serial 7 -dnl Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc. +# strstr.m4 serial 16 +dnl Copyright (C) 2008-2013 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. @@ -11,7 +11,51 @@ AC_DEFUN([gl_FUNC_STRSTR_SIMPLE], AC_REQUIRE([gl_FUNC_MEMCHR]) if test "$gl_cv_func_memchr_works" != yes; then REPLACE_STRSTR=1 - AC_LIBOBJ([strstr]) + else + dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092. + AC_CACHE_CHECK([whether strstr works], + [gl_cv_func_strstr_works_always], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ +#include <string.h> /* for strstr */ +#define P "_EF_BF_BD" +#define HAYSTACK "F_BD_CE_BD" P P P P "_C3_88_20" P P P "_C3_A7_20" P +#define NEEDLE P P P P P +]], [[return !!strstr (HAYSTACK, NEEDLE); + ]])], + [gl_cv_func_strstr_works_always=yes], + [gl_cv_func_strstr_works_always=no], + [dnl glibc 2.12 and cygwin 1.7.7 have a known bug. uClibc is not + dnl affected, since it uses different source code for strstr than + dnl glibc. + dnl Assume that it works on all other platforms, even if it is not + dnl linear. + AC_EGREP_CPP([Lucky user], + [ +#ifdef __GNU_LIBRARY__ + #include <features.h> + #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \ + || defined __UCLIBC__ + Lucky user + #endif +#elif defined __CYGWIN__ + #include <cygwin/version.h> + #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7) + Lucky user + #endif +#else + Lucky user +#endif + ], + [gl_cv_func_strstr_works_always="guessing yes"], + [gl_cv_func_strstr_works_always="guessing no"]) + ]) + ]) + case "$gl_cv_func_strstr_works_always" in + *yes) ;; + *) + REPLACE_STRSTR=1 + ;; + esac fi ]) # gl_FUNC_STRSTR_SIMPLE @@ -24,16 +68,18 @@ AC_DEFUN([gl_FUNC_STRSTR], [gl_cv_func_strstr_linear], [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ #include <signal.h> /* for signal */ -#include <string.h> /* for memmem */ +#include <string.h> /* for strstr */ #include <stdlib.h> /* for malloc */ #include <unistd.h> /* for alarm */ -]], [[size_t m = 1000000; +static void quit (int sig) { exit (sig + 128); } +]], [[ + int result = 0; + size_t m = 1000000; char *haystack = (char *) malloc (2 * m + 2); char *needle = (char *) malloc (m + 2); - void *result = 0; /* Failure to compile this test due to missing alarm is okay, since all such platforms (mingw) also have quadratic strstr. */ - signal (SIGALRM, SIG_DFL); + signal (SIGALRM, quit); alarm (5); /* Check for quadratic performance. */ if (haystack && needle) @@ -44,36 +90,41 @@ AC_DEFUN([gl_FUNC_STRSTR], memset (needle, 'A', m); needle[m] = 'B'; needle[m + 1] = 0; - result = strstr (haystack, needle); + if (!strstr (haystack, needle)) + result |= 1; } - return !result;]])], + return result; + ]])], [gl_cv_func_strstr_linear=yes], [gl_cv_func_strstr_linear=no], - [dnl Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a - dnl strstr that works in linear time. + [dnl Only glibc > 2.12 on processors without SSE 4.2 instructions and + dnl cygwin > 1.7.7 are known to have a bug-free strstr that works in + dnl linear time. AC_EGREP_CPP([Lucky user], [ #include <features.h> #ifdef __GNU_LIBRARY__ - #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2) + #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \ + && !(defined __i386__ || defined __x86_64__) \ + && !defined __UCLIBC__ Lucky user #endif #endif #ifdef __CYGWIN__ #include <cygwin/version.h> - #if CYGWIN_VERSION_DLL_MAJOR >= 1007 + #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7) Lucky user #endif #endif ], - [gl_cv_func_strstr_linear=yes], + [gl_cv_func_strstr_linear="guessing yes"], [gl_cv_func_strstr_linear="guessing no"]) ]) ]) - if test "$gl_cv_func_strstr_linear" != yes; then - REPLACE_STRSTR=1 - fi - fi - if test $REPLACE_STRSTR = 1; then - AC_LIBOBJ([strstr]) + case "$gl_cv_func_strstr_linear" in + *yes) ;; + *) + REPLACE_STRSTR=1 + ;; + esac fi ]) # gl_FUNC_STRSTR |