autoconf: don't use platform regex if it lacks REG_STARTEND

If the platform regex cannot match null bytes, we might as well
use the glibc version instead.

Cc: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Cc: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Tested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/config.mak.in b/config.mak.in
index b4e65c32b235eafafefeed1c755be7e1ad5c71ae..67dbd3b7399b0d5bbb1e0c9e01e14d92b6aa1b55 100644 (file)
--- a/config.mak.in
+++ b/config.mak.in
@@ -58,6 +58,7 @@ NO_INET_NTOP=@NO_INET_NTOP@
 NO_INET_PTON=@NO_INET_PTON@
 NO_ICONV=@NO_ICONV@
 OLD_ICONV=@OLD_ICONV@
+NO_REGEX=@NO_REGEX@
 NO_DEFLATE_BOUND=@NO_DEFLATE_BOUND@
 INLINE=@INLINE@
 SOCKLEN_T=@SOCKLEN_T@

diff --git a/configure.ac b/configure.ac
index 5601e8bac953c670e35f32ffe48d157dd5694ce7..71ac89fab3f8ad7298059af251eb06e30227b334 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -706,6 +706,27 @@ else
 fi
 AC_SUBST(NO_C99_FORMAT)
 #
+# Define NO_REGEX if you have no or inferior regex support in your C library.
+AC_CACHE_CHECK([whether the platform regex can handle null bytes],
+ [ac_cv_c_excellent_regex], [
+AC_EGREP_CPP(yippeeyeswehaveit,
+       AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
+#include <regex.h>
+],
+[#ifdef REG_STARTEND
+yippeeyeswehaveit
+#endif
+]),
+       [ac_cv_c_excellent_regex=yes],
+       [ac_cv_c_excellent_regex=yes])
+])
+if test $ac_cv_c_excellent_regex = yes; then
+       NO_REGEX=
+else
+       NO_REGEX=YesPlease
+fi
+AC_SUBST(NO_REGEX)
+#
 # Define FREAD_READS_DIRECTORIES if your are on a system which succeeds
 # when attempting to read from an fopen'ed directory.
 AC_CACHE_CHECK([whether system succeeds to read fopen'ed directory],