Use a proper test for detecting usable std::regex

The test is stolen from cmake code.

Tested on:

* ubuntu 12.04 with g++ 4.6, clang 3.3 (with libstdc++)

* ubuntu 16.04 with g++ 5.3, clang 3.7 (with libstdc++) and clang 3.7
  (with libc++)

The last combination fails, but it seems to be related to real bugs
(reported for debian), so this is OK.
This commit is contained in:
Jean-Marc Lasgouttes 2016-07-06 14:49:18 +02:00
parent 23dbcb59d2
commit 14a6a4723f

View File

@ -195,8 +195,7 @@ AC_DEFUN([LYX_CXX_CXX11_FLAGS],
check_type c;
check_type&& cr = static_cast<check_type&&>(c);
auto d = a;],
[return 0;],
auto d = a;], [],
[lyx_cv_cxx11_flags=$flag; break])
AC_LANG_POP(C++)
CXXFLAGS=$save_CXXFLAGS
@ -205,43 +204,44 @@ AC_DEFUN([LYX_CXX_CXX11_FLAGS],
if test $lyx_cv_cxx11_flags = none ; then
AC_ERROR([Cannot find suitable C++11 mode for compiler $CXX])
fi
lyx_cxx11_flags=$lyx_cv_cxx11_flags
AM_CXXFLAGS="$lyx_cxx11_flags $AM_CXXFLAGS"
AM_CXXFLAGS="$lyx_cv_cxx11_flags $AM_CXXFLAGS"
])
dnl Usage: LYX_CXX_USE_REGEX(cxx11_flags)
dnl Usage: LYX_CXX_USE_REGEX
dnl decide whether we want to use std::regex and set the
dnl LYX_USE_STD_REGEX accordingly.
dnl the extra cxx11 flags have to be passed to the preprocessor. They are
dnl not plainly added to AM_CPPFLAGS because then the objc compiler (mac)
dnl would fail.
dnl LYX_USE_STD_REGEX macro and conditional accordingly.
AC_DEFUN([LYX_CXX_USE_REGEX],
[AC_ARG_ENABLE(std-regex,
AC_HELP_STRING([--enable-std-regex],[use std::regex instead of boost::regex (default is autodetected)]),
[lyx_std_regex=$enableval],
[save_CPPFLAGS=$CPPFLAGS
# we want to pass -std=c++11 to clang/cpp if necessary
CPPFLAGS="$AM_CPPFLAGS $1 $CPPFLAGS"
[AC_MSG_CHECKING([for correct regex implementation])
save_CPPFLAGS=$CPPFLAGS
CPPFLAGS="$AM_CPPFLAGS $CPPFLAGS"
save_CXXFLAGS=$CXXFLAGS
CXXFLAGS="$AM_CXXFLAGS $CXXFLAGS"
AC_LANG_PUSH(C++)
AC_CHECK_HEADER([regex], [lyx_std_regex=yes], [lyx_std_regex=no])
# The following code snippet has been taken taken from example in
# http://stackoverflow.com/questions/8561850/compile-stdregex-iterator-with-gcc
AC_TRY_LINK(
[
#include <regex>
#include <iostream>
#include <string.h>
typedef std::regex_iterator<const char *> Myiter;
], [
const char *pat = "axayaz";
Myiter::regex_type rx("a");
Myiter next(pat, pat + strlen(pat), rx);
Myiter end;
], [lyx_std_regex=yes], [lyx_std_regex=no])
AC_LANG_POP(C++)
CXXFLAGS=$save_CXXFLAGS
CPPFLAGS=$save_CPPFLAGS
if test x$GXX = xyes && test $lyx_std_regex = yes ; then
AC_MSG_CHECKING([for correct regex implementation])
if test x$CLANG = xno || test $lyx_cv_lib_stdcxx = yes; then
dnl <regex> in gcc is unusable in versions less than 4.9.0
dnl see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53631
case $gxx_version in
4.6*|4.7*|4.8*) lyx_std_regex=no ;;
*) ;;
esac
fi
AC_MSG_RESULT([$lyx_std_regex])
fi])
AC_MSG_RESULT([$lyx_std_regex])
])
if test $lyx_std_regex = yes ; then
lyx_flags="$lyx_flags std-regex"
@ -413,7 +413,7 @@ if test x$GXX = xyes; then
esac
fi
LYX_CXX_USE_REGEX([$lyx_cxx11_flags])
LYX_CXX_USE_REGEX
])
dnl Usage: LYX_USE_INCLUDED_BOOST : select if the included boost should