improve support for using libc++ on Linux and for libc++ debug mode

It seems to run slightly faster in --enable-dbgutil mode and also
builds a bit faster (at least with Clang). But libc++ on Mac
isn't built with debug mode support.

Change-Id: Idf5dba9c4a56aba1f4163aa518a78d34b6837149
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/133664
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

5 files changed, 34 insertions, 0 deletions

diff --git a/config_host.mk.in b/config_host.mk.in
index 8d7fe3c12865..e129b28bfeee 100644
--- a/config_host.mk.in
+++ b/config_host.mk.in
@@ -304,6 +304,8 @@ export HAVE_GCC_STACK_CLASH_PROTECTION=@HAVE_GCC_STACK_CLASH_PROTECTION@
 export HAVE_GNUMAKE_FILE_FUNC=@HAVE_GNUMAKE_FILE_FUNC@
 export HAVE_LD_BSYMBOLIC_FUNCTIONS=@HAVE_LD_BSYMBOLIC_FUNCTIONS@
 export HAVE_LD_HASH_STYLE=@HAVE_LD_HASH_STYLE@
+export HAVE_LIBCPP=@HAVE_LIBCPP@
+export HAVE_LIBCPP_DEBUG=@HAVE_LIBCPP_DEBUG@
 export HAVE_LIBSTDCPP=@HAVE_LIBSTDCPP@
 export HAVE_POSIX_FALLOCATE=@HAVE_POSIX_FALLOCATE@
 export HAVE_WDEPRECATED_COPY_DTOR=@HAVE_WDEPRECATED_COPY_DTOR@
diff --git a/configure.ac b/configure.ac
index cdef1a6507e5..c4e71a8a12ff 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7371,6 +7371,7 @@ dnl ===================================================================
 
 AC_MSG_CHECKING([what the C++ library is])
 HAVE_LIBSTDCPP=
+HAVE_LIBCPP=
 AC_LANG_PUSH([C++])
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <utility>
@@ -7391,6 +7392,7 @@ foo bar
     [CPP_LIBRARY=LIBCPP
      cpp_library_name="LLVM libc++"
      AC_DEFINE([HAVE_LIBCXX])
+     HAVE_LIBCPP=TRUE
     ],
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <utility>
@@ -7405,6 +7407,27 @@ foo bar
 AC_MSG_RESULT([$cpp_library_name])
 AC_LANG_POP([C++])
 AC_SUBST([HAVE_LIBSTDCPP])
+AC_SUBST([HAVE_LIBCPP])
+
+HAVE_LIBCPP_DEBUG=
+if test -n "$HAVE_LIBCPP" -a -n "$ENABLE_DBGUTIL"; then
+    # libc++ supports debug mode only if built for it, Mac libc++ isn't,
+    # and there would be undefined references to debug functions
+    AC_MSG_CHECKING([if libc++ is built with debug mode])
+    AC_LANG_PUSH([C++])
+    AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#define _LIBCPP_DEBUG 1
+#include <vector>
+int foo(const std::vector<int>& v) { return *v.begin(); }
+]])],
+    [AC_MSG_RESULT(yes)
+     HAVE_LIBCPP_DEBUG=1
+    ],
+    [AC_MSG_RESULT(no)]
+    )
+    AC_LANG_POP([C++])
+fi
+AC_SUBST([HAVE_LIBCPP_DEBUG])
 
 dnl ===================================================================
 dnl Check for gperf
diff --git a/external/clucene/Library_clucene.mk b/external/clucene/Library_clucene.mk
index 6f585f6f2bfa..c6f2895501d6 100644
--- a/external/clucene/Library_clucene.mk
+++ b/external/clucene/Library_clucene.mk
@@ -41,6 +41,7 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,clucene,\
 	-lm \
 	-ldl \
+	-pthread \
 ))
 endif
 
diff --git a/solenv/gbuild/platform/com_GCC_defs.mk b/solenv/gbuild/platform/com_GCC_defs.mk
index c7cc1c3ef577..c2db27243457 100644
--- a/solenv/gbuild/platform/com_GCC_defs.mk
+++ b/solenv/gbuild/platform/com_GCC_defs.mk
@@ -53,6 +53,10 @@ gb_COMPILERDEFS := \
 ifeq ($(gb_ENABLE_DBGUTIL),$(true))
 ifneq ($(HAVE_LIBSTDCPP),)
 gb_COMPILERDEFS_STDLIB_DEBUG = -D_GLIBCXX_DEBUG
+else
+ifneq ($(HAVE_LIBCPP_DEBUG),)
+gb_COMPILERDEFS_STDLIB_DEBUG = -D_LIBCPP_DEBUG=1
+endif
 endif
 gb_COMPILERDEFS += $(gb_COMPILERDEFS_STDLIB_DEBUG)
 endif
diff --git a/solenv/gbuild/platform/unxgcc.mk b/solenv/gbuild/platform/unxgcc.mk
index b98732030b32..b3388eec436a 100644
--- a/solenv/gbuild/platform/unxgcc.mk
+++ b/solenv/gbuild/platform/unxgcc.mk
@@ -47,6 +47,10 @@ gb_CFLAGS := \
 ifneq ($(HAVE_LIBSTDCPP),)
 gb_CXX_LINKFLAGS := -pthread
 endif
+# libc++ needs it too
+ifneq ($(HAVE_LIBCPP),)
+gb_CXX_LINKFLAGS := -pthread
+endif
 
 gb_CXXFLAGS := \
 	$(gb_CXXFLAGS_COMMON) \