From be41e2d16f551103a9b7c5d22cb774eb5bfcb0d9 Mon Sep 17 00:00:00 2001
From: Georg Baum <baum@lyx.org>
Date: Tue, 12 May 2015 21:23:06 +0200
Subject: [PATCH 153/163] Fix build with GNU libstdc++ C++11 ABI
The GNU libstdc++ that ships witch gcc 5 can be used with the same ABI as
older versions, or with a new ABI which is conformant to the C++11 standard.
LyX did not build if the latter was used:
https://kojipkgs.fedoraproject.org//work/tasks/1267/9651267/build.log
This is now fixed by detecting the ABI version and disabling the wrong forward
declarations. At the same time, STD_STRING_USES_COW is switched off for the
C++11 ABI version, because the std::basic_string implementation is now C++11
conformant. Since the GNU libstdc++ can also used by other compilers such as
clang, we must not test for the compiler version.
---
config/lyxinclude.m4 | 80 ++++++++++++++++++++++-----------
development/cmake/ConfigureChecks.cmake | 46 +++++++++++++++++++
development/cmake/config.h.cmake | 3 ++
src/support/strfwd.h | 14 ++----
status.21x | 3 ++
5 files changed, 110 insertions(+), 36 deletions(-)
diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index 61ea48d..a0094c1 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -120,37 +120,65 @@ done
])dnl
-AC_DEFUN([LYX_PROG_CXX_WORKS],
-[rm -f conftest.C
-cat >conftest.C <<EOF
-class foo {
- // we require the mutable keyword
- mutable int bar;
- };
- // we require namespace support
- namespace baz {
- int bar;
- }
- int main() {
- return(0);
- }
-EOF
-$CXX -c $CXXFLAGS $CPPFLAGS conftest.C >&5 || CXX=
-rm -f conftest.C conftest.o conftest.obj || true
+dnl Usage: LYX_PROG_CLANG: set lyx_cv_prog_clang to yes if the compiler is clang.
+AC_DEFUN([LYX_PROG_CLANG],
+[AC_CACHE_CHECK([whether the compiler is clang],
+ [lyx_cv_prog_clang],
+[AC_TRY_COMPILE([], [
+#ifndef __clang__
+ this is not clang
+#endif
+],
+[lyx_cv_prog_clang=yes ; CLANG=yes], [lyx_cv_prog_clang=no ; CLANG=no])])
])
-AC_DEFUN([LYX_PROG_CXX],
-[AC_MSG_CHECKING([for a good enough C++ compiler])
-LYX_SEARCH_PROG(CXX, $CXX $CCC g++ gcc c++ CC cxx xlC cc++, [LYX_PROG_CXX_WORKS])
+dnl Usage: LYX_LIB_STDCXX: set lyx_cv_lib_stdcxx to yes if the STL library is libstdc++.
+AC_DEFUN([LYX_LIB_STDCXX],
+[AC_CACHE_CHECK([whether STL is libstdc++],
+ [lyx_cv_lib_stdcxx],
+[AC_TRY_COMPILE([#include<vector>], [
+#if ! defined(__GLIBCXX__) && ! defined(__GLIBCPP__)
+ this is not libstdc++
+#endif
+],
+[lyx_cv_lib_stdcxx=yes], [lyx_cv_lib_stdcxx=no])])
+])
-if test -z "$CXX" ; then
- AC_MSG_ERROR([Unable to find a good enough C++ compiler])
-fi
-AC_MSG_RESULT($CXX)
-AC_PROG_CXX
-AC_PROG_CXXCPP
+dnl Usage: LYX_LIB_STDCXX_CXX11_ABI: set lyx_cv_lib_stdcxx_cxx11_abi to yes
+dnl if the STL library is GNU libstdc++ and the C++11 ABI is used.
+AC_DEFUN([LYX_LIB_STDCXX_CXX11_ABI],
+[AC_CACHE_CHECK([whether STL is libstdc++ using the C++11 ABI],
+ [lyx_cv_lib_stdcxx_cxx11_abi],
+[AC_TRY_COMPILE([#include<vector>], [
+#if ! defined(_GLIBCXX_USE_CXX11_ABI) || ! _GLIBCXX_USE_CXX11_ABI
+ this is not libstdc++ using the C++11 ABI
+#endif
+],
+[lyx_cv_lib_stdcxx_cxx11_abi=yes], [lyx_cv_lib_stdcxx_cxx11_abi=no])])
+])
+
+
+AC_DEFUN([LYX_PROG_CXX],
+[AC_REQUIRE([AC_PROG_CXX])
+AC_REQUIRE([AC_PROG_CXXCPP])
+
+AC_LANG_PUSH(C++)
+LYX_PROG_CLANG
+LYX_LIB_STDCXX
+LYX_LIB_STDCXX_CXX11_ABI
+AC_LANG_POP(C++)
+
+if test $lyx_cv_lib_stdcxx = "yes" ; then
+ if test $lyx_cv_lib_stdcxx_cxx11_abi = "yes" ; then
+ AC_DEFINE(USE_GLIBCXX_CXX11_ABI, 1, [use GNU libstdc++ with C++11 ABI])
+ fi
+else
+ if test $lyx_cv_prog_clang = "yes" ; then
+ AC_DEFINE(USE_LLVM_LIBCPP, 1, [use libc++ provided by llvm instead of GNU libstdc++])
+ fi
+fi
### We might want to get or shut warnings.
AC_ARG_ENABLE(warnings,
diff --git a/development/cmake/ConfigureChecks.cmake b/development/cmake/ConfigureChecks.cmake
index 71291a5..a738160 100644
--- a/development/cmake/ConfigureChecks.cmake
+++ b/development/cmake/ConfigureChecks.cmake
@@ -112,3 +112,49 @@ check_cxx_source_compiles(
"
SIZEOF_WCHAR_T_IS_4)
+# Check whether STL is libstdc++
+check_cxx_source_compiles(
+ "
+ #include <vector>
+ int main() {
+ #if ! defined(__GLIBCXX__) && ! defined(__GLIBCPP__)
+ this is not libstdc++
+ #endif
+ return(0);
+ }
+ "
+lyx_cv_lib_stdcxx)
+
+# Check whether STL is libstdc++ with C++11 ABI
+check_cxx_source_compiles(
+ "
+ #include <vector>
+ int main() {
+ #if ! defined(_GLIBCXX_USE_CXX11_ABI) || ! _GLIBCXX_USE_CXX11_ABI
+ this is not libstdc++ using the C++11 ABI
+ #endif
+ return(0);
+ }
+ "
+USE_GLIBCXX_CXX11_ABI)
+
+check_cxx_source_compiles(
+ "
+ #ifndef __clang__
+ this is not clang
+ #endif
+ int main() {
+ return(0);
+ }
+ "
+lyx_cv_prog_clang)
+
+set(USE_LLVM_LIBCPP)
+set(USE_GLIBCXX_CXX11_ABI)
+if(NOT lyx_cv_lib_stdcxx)
+ if(lyx_cv_prog_clang)
+ # use libc++ provided by llvm instead of GNU libstdc++
+ set(USE_LLVM_LIBCPP 1)
+ endif()
+endif()
+
diff --git a/development/cmake/config.h.cmake b/development/cmake/config.h.cmake
index 7bbe09e..a392b51 100644
--- a/development/cmake/config.h.cmake
+++ b/development/cmake/config.h.cmake
@@ -57,6 +57,9 @@
#cmakedefine LYX_USE_TR1 1
#cmakedefine LYX_USE_TR1_REGEX 1
+// use GNU libstdc++ with C++11 ABI
+#cmakedefine USE_GLIBCXX_CXX11_ABI 1
+
#cmakedefine Z_PREFIX 1
#cmakedefine ASPELL_FOUND 1
diff --git a/src/support/strfwd.h b/src/support/strfwd.h
index de8588c..f39426e 100644
--- a/src/support/strfwd.h
+++ b/src/support/strfwd.h
@@ -13,14 +13,6 @@
#ifndef STRFWD_H
#define STRFWD_H
-// This includes does nothing but defining _LIBCPP_VERSION
-// if libc++ is used (rather than libstdc++) - we first
-// check if we have at least a c++03 standard before
-// including the file
-#if (__cplusplus > 19971L)
-#include <ciso646>
-#endif
-
#ifdef USE_WCHAR_T
// Prefer this if possible because GNU libstdc++ has usable
@@ -36,8 +28,10 @@ namespace lyx { typedef boost::uint32_t char_type; }
#endif
-// Forward definitions do not work with libc++
-#ifdef _LIBCPP_VERSION
+// For gcc5 with the new std::string ABI forward declarations would work in
+// principle, but I am not sure whether we want non-standard
+// "namespace __cxx11" in our sources.
+#if defined(USE_LLVM_LIBCPP) || defined(USE_GLIBCXX_CXX11_ABI)
#include <string>
#else
--
1.9.3