- AC_CACHE_CHECK([whether strstr works in linear time],
- [gl_cv_func_strstr_linear],
- [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+ AC_REQUIRE([gl_FUNC_MEMCHR])
+ if test "$gl_cv_func_memchr_works" != yes; then
+ REPLACE_STRSTR=1
+ AC_LIBOBJ([strstr])
+ fi
+]) # gl_FUNC_STRSTR_SIMPLE
+
+dnl Additionally, check that strstr is efficient.
+AC_DEFUN([gl_FUNC_STRSTR],
+[
+ AC_REQUIRE([gl_FUNC_STRSTR_SIMPLE])
+ if test $REPLACE_STRSTR = 0; then
+ AC_CACHE_CHECK([whether strstr works in linear time],
+ [gl_cv_func_strstr_linear],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <signal.h> /* for signal */