1# strcasestr.m4 serial 21 2dnl Copyright (C) 2005, 2007-2014 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7dnl Check that strcasestr is present and works. 8AC_DEFUN([gl_FUNC_STRCASESTR_SIMPLE], 9[ 10 AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS]) 11 12 dnl Persuade glibc <string.h> to declare strcasestr(). 13 AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) 14 15 AC_REQUIRE([gl_FUNC_MEMCHR]) 16 AC_CHECK_FUNCS([strcasestr]) 17 if test $ac_cv_func_strcasestr = no; then 18 HAVE_STRCASESTR=0 19 else 20 if test "$gl_cv_func_memchr_works" != yes; then 21 REPLACE_STRCASESTR=1 22 else 23 dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092. 24 AC_CACHE_CHECK([whether strcasestr works], 25 [gl_cv_func_strcasestr_works_always], 26 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ 27#include <string.h> /* for strcasestr */ 28#define P "_EF_BF_BD" 29#define HAYSTACK "F_BD_CE_BD" P P P P "_C3_88_20" P P P "_C3_A7_20" P 30#define NEEDLE P P P P P 31]], [[return !!strcasestr (HAYSTACK, NEEDLE); 32 ]])], 33 [gl_cv_func_strcasestr_works_always=yes], 34 [gl_cv_func_strcasestr_works_always=no], 35 [dnl glibc 2.12 and cygwin 1.7.7 have a known bug. uClibc is not 36 dnl affected, since it uses different source code for strcasestr 37 dnl than glibc. 38 dnl Assume that it works on all other platforms, even if it is not 39 dnl linear. 40 AC_EGREP_CPP([Lucky user], 41 [ 42#ifdef __GNU_LIBRARY__ 43 #include <features.h> 44 #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \ 45 || defined __UCLIBC__ 46 Lucky user 47 #endif 48#elif defined __CYGWIN__ 49 #include <cygwin/version.h> 50 #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7) 51 Lucky user 52 #endif 53#else 54 Lucky user 55#endif 56 ], 57 [gl_cv_func_strcasestr_works_always="guessing yes"], 58 [gl_cv_func_strcasestr_works_always="guessing no"]) 59 ]) 60 ]) 61 case "$gl_cv_func_strcasestr_works_always" in 62 *yes) ;; 63 *) 64 REPLACE_STRCASESTR=1 65 ;; 66 esac 67 fi 68 fi 69]) # gl_FUNC_STRCASESTR_SIMPLE 70 71dnl Additionally, check that strcasestr is efficient. 72AC_DEFUN([gl_FUNC_STRCASESTR], 73[ 74 AC_REQUIRE([gl_FUNC_STRCASESTR_SIMPLE]) 75 if test $HAVE_STRCASESTR = 1 && test $REPLACE_STRCASESTR = 0; then 76 AC_CACHE_CHECK([whether strcasestr works in linear time], 77 [gl_cv_func_strcasestr_linear], 78 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ 79#include <signal.h> /* for signal */ 80#include <string.h> /* for strcasestr */ 81#include <stdlib.h> /* for malloc */ 82#include <unistd.h> /* for alarm */ 83static void quit (int sig) { exit (sig + 128); } 84]], [[ 85 int result = 0; 86 size_t m = 1000000; 87 char *haystack = (char *) malloc (2 * m + 2); 88 char *needle = (char *) malloc (m + 2); 89 /* Failure to compile this test due to missing alarm is okay, 90 since all such platforms (mingw) also lack strcasestr. */ 91 signal (SIGALRM, quit); 92 alarm (5); 93 /* Check for quadratic performance. */ 94 if (haystack && needle) 95 { 96 memset (haystack, 'A', 2 * m); 97 haystack[2 * m] = 'B'; 98 haystack[2 * m + 1] = 0; 99 memset (needle, 'A', m); 100 needle[m] = 'B'; 101 needle[m + 1] = 0; 102 if (!strcasestr (haystack, needle)) 103 result |= 1; 104 } 105 return result; 106 ]])], 107 [gl_cv_func_strcasestr_linear=yes], [gl_cv_func_strcasestr_linear=no], 108 [dnl Only glibc > 2.12 and cygwin > 1.7.7 are known to have a 109 dnl strcasestr that works in linear time. 110 AC_EGREP_CPP([Lucky user], 111 [ 112#include <features.h> 113#ifdef __GNU_LIBRARY__ 114 #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \ 115 && !defined __UCLIBC__ 116 Lucky user 117 #endif 118#endif 119#ifdef __CYGWIN__ 120 #include <cygwin/version.h> 121 #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7) 122 Lucky user 123 #endif 124#endif 125 ], 126 [gl_cv_func_strcasestr_linear="guessing yes"], 127 [gl_cv_func_strcasestr_linear="guessing no"]) 128 ]) 129 ]) 130 case "$gl_cv_func_strcasestr_linear" in 131 *yes) ;; 132 *) 133 REPLACE_STRCASESTR=1 134 ;; 135 esac 136 fi 137]) # gl_FUNC_STRCASESTR 138 139# Prerequisites of lib/strcasestr.c. 140AC_DEFUN([gl_PREREQ_STRCASESTR], [ 141 : 142]) 143