X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=config%2Flyxinclude.m4;h=33c59794162ebb9c0eff9e290876755ab6eb541a;hb=c1c439b94dd6d5802e9a48b8c4e45c13fad6f869;hp=de7506fbfcc8ceeeb38455a0a6e7101f84f07e28;hpb=dd2be1777f107276cbbfa4be5f15b5164af739af;p=lyx.git

diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index de7506fbfc..33c5979416 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -143,7 +143,7 @@ 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([for clang],
+[AC_CACHE_CHECK([whether the compiler is clang],
                [lyx_cv_prog_clang],
 [AC_TRY_COMPILE([], [
 #ifndef __clang__
@@ -154,6 +154,19 @@ AC_DEFUN([LYX_PROG_CLANG],
 ])
 
 
+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])])
+])
+
+
 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])
@@ -167,8 +180,17 @@ AC_REQUIRE([AC_PROG_CXX])
 AC_REQUIRE([AC_PROG_CXXCPP])
 AC_LANG_PUSH(C++)
 LYX_PROG_CLANG
+LYX_LIB_STDCXX
 AC_LANG_POP(C++)
 
+if test $lyx_cv_lib_stdcxx = "yes" ; then
+  AC_DEFINE(STD_STRING_USES_COW, 1, [std::string uses copy-on-write])
+else
+  if test $lyx_cv_prog_clang = "yes" ; then
+    AC_DEFINE(USE_LLVM_LIBCPP, 1, [use libc++ provided by llvm instead of GNU libstdc++])
+  fi
+fi
+
 ### We might want to get or shut warnings.
 AC_ARG_ENABLE(warnings,
   AC_HELP_STRING([--enable-warnings],[tell the compiler to display more warnings]),,
@@ -320,8 +342,6 @@ if test x$GXX = xyes; then
 	      ;;
       esac
   fi
-  dnl FIXME: this should be conditional to the use of libstdc++
-  AC_DEFINE(STD_STRING_USES_COW, 1, [std::string uses copy-on-write])
 fi
 test "$lyx_pch_comp" = yes && lyx_flags="$lyx_flags pch"
 AM_CONDITIONAL(LYX_BUILD_PCH, test "$lyx_pch_comp" = yes)