From d4a1b345dd16591ff6f17c67ee519afebe2f9792 Mon Sep 17 00:00:00 2001 From: sezero Date: Tue, 8 Oct 2019 20:25:55 +0300 Subject: [PATCH] configure.ac: allow several compiler flags for clang The flac configury marked clang as 'not being gcc' and excluded a lot of compiler switches, most importantly the visibility flags, from being used with it. This was done possibly after a problem reported at: https://github.com/erikd/libsndfile/issues/49 . This patch does the following: - m4/gcc_version.m4 (XIPH_GCC_VERSION): set GCC_MAJOR_VERSION and GCC_MINOR_VERSION to 0 for non-gcc. Previously, they were left unset. - configure: the gcc version checks are, naturally, against non- zero values, so, allow many compiler switches to be used with clang without affecting real-gcc cases. - configure: When setting CFLAGS="-O3 -funroll-loops", also set CXXFLAGS="-O3". Prevents g++ warnings with _FORTIFY_SOURCE, i.e.: '_FORTIFY_SOURCE requires compiling with optimization (-O)' Tested compilation using gcc-7.3.1 and clang-5.0.2 on x86_64-linux, and gcc-4.4.7 and clang-3.4.2 on an i686-linux. Also tested cross- compiling for Mac OS X using clang-5.0.2. --- configure.ac | 18 ++++++++++++++---- m4/gcc_version.m4 | 3 +++ 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/configure.ac b/configure.ac index 6efefaf5..88f89a91 100644 --- a/configure.ac +++ b/configure.ac @@ -429,11 +429,12 @@ dnl If debugging is disabled AND no CFLAGS/CXXFLAGS/CPPFLAGS/LDFLAGS dnl are provided, we can set defaults to our liking AS_IF([test "x${ax_enable_debug}" = "xno" && test "x${enable_flags_setting}" = "xyes"], [ CFLAGS="-O3 -funroll-loops" + CXXFLAGS="-O3" ]) -XIPH_GCC_VERSION +XIPH_GCC_VERSION dnl Sets a non-zero GCC_XXX_VERSION for gcc, not clang. checks below rely on that.. -if test x$ac_cv_c_compiler_gnu = xyes ; then +if test x$ac_cv_c_compiler_gnu = xyes -o x$xiph_cv_c_compiler_clang = xyes ; then CFLAGS="$CFLAGS -Wall -Wextra -Wstrict-prototypes -Wmissing-prototypes -Waggregate-return -Wcast-align -Wnested-externs -Wshadow -Wundef -Wmissing-declarations -Winline " # -Wcast-qual -Wbad-function-cast -Wwrite-strings -Wconversion CXXFLAGS="$CXXFLAGS -Wall -Wextra -Wcast-align -Wshadow -Wwrite-strings -Wctor-dtor-privacy -Wnon-virtual-dtor -Wreorder -Wsign-promo -Wundef " # -Wcast-qual -Wbad-function-cast -Wwrite-strings -Woverloaded-virtual -Wmissing-declarations @@ -448,13 +449,22 @@ if test x$ac_cv_c_compiler_gnu = xyes ; then XIPH_ADD_CXXFLAGS([-Weffc++]) AC_LANG_POP([C++]) - if test "$GCC_MAJOR_VERSION" -ge 4 && test "$OBJ_FORMAT" = elf; then + if test x$xiph_cv_c_compiler_clang = xyes -a "$OBJ_FORMAT" = elf; then + CPPFLAGS="$CPPFLAGS -DFLAC__USE_VISIBILITY_ATTR" + CFLAGS="$CFLAGS -fvisibility=hidden" + CXXFLAGS="$CXXFLAGS -fvisibility=hidden" + elif test "$GCC_MAJOR_VERSION" -ge 4 && test "$OBJ_FORMAT" = elf; then CPPFLAGS="$CPPFLAGS -DFLAC__USE_VISIBILITY_ATTR" CFLAGS="$CFLAGS -fvisibility=hidden" CXXFLAGS="$CXXFLAGS -fvisibility=hidden" fi - if test "$GCC_MAJOR_VERSION" -ge 4 && test "$OBJ_FORMAT" = macho; then + + if test x$xiph_cv_c_compiler_clang = xyes -a "$OBJ_FORMAT" = macho; then + CPPFLAGS="$CPPFLAGS -DFLAC__USE_VISIBILITY_ATTR" + CFLAGS="$CFLAGS -fvisibility=hidden" + CXXFLAGS="$CXXFLAGS -fvisibility=hidden" + elif test "$GCC_MAJOR_VERSION" -ge 4 && test "$OBJ_FORMAT" = macho; then CPPFLAGS="$CPPFLAGS -DFLAC__USE_VISIBILITY_ATTR" CFLAGS="$CFLAGS -fvisibility=hidden" CXXFLAGS="$CXXFLAGS -fvisibility=hidden" diff --git a/m4/gcc_version.m4 b/m4/gcc_version.m4 index 1c53086f..e6aaa603 100644 --- a/m4/gcc_version.m4 +++ b/m4/gcc_version.m4 @@ -22,6 +22,9 @@ if test "x$ac_cv_c_compiler_gnu" = "xyes" ; then GCC_MAJOR_VERSION=`echo $GCC_VERSION | cut -d. -f 1` GCC_MINOR_VERSION=`echo $GCC_VERSION | cut -d. -f 2` +else + GCC_MAJOR_VERSION=0 + GCC_MINOR_VERSION=0 fi AC_SUBST(GCC_VERSION)