clang/mac: Bundle libc++.dylib with clang.

clang now uses c++11, which on OS X means it depends on libc++.
OS X 10.6 doesn't have libc++ yet, but some bots still are on 10.6 and
upgrading them will take a bit longer. Bundle libc++ with the clang package,
and set rpaths so that both clang and plugins refer to the bundled libc++
instead of /usr/lib/libc++.1.dylib.

(System libraries will still cause libstdc++ to be loaded as well. Since libc++
keeps its symbols in std::__1:: and aliases everything to that, loading libc++
and libstdc++ in the same process is safe.)

Also don't set MACOSX_DEPLOYMENT_TARGET while building the bootstrap
compiler (Xcode's clang complains when using -stdlib=libc++ when targeting
10.6 or older; open-source luckily doesn't for some reason).

Also pass -isysroot; when building on OS X 10.9, /usr/include doesn't exist
unless the command line tools are installed.

BUG=358500
TEST=Run package.sh (with a tweaked clang revision, to not clobber an
existing package). Upload produced tgz file somewhere, download it on
a 10.6 box. Clang should run.

R=hans@chromium.org

Review URL: https://codereview.chromium.org/218613009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260908 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 63 insertions, 13 deletions

diff --git a/tools/clang/blink_gc_plugin/Makefile b/tools/clang/blink_gc_plugin/Makefile
index d6e7da9..29e3834 100644
--- a/tools/clang/blink_gc_plugin/Makefile
+++ b/tools/clang/blink_gc_plugin/Makefile
@@ -17,5 +17,5 @@ SHARED_LIBRARY = 1
 include $(CLANG_LEVEL)/Makefile
 
 ifeq ($(OS),Darwin)
-  LDFLAGS=-Wl,-undefined,dynamic_lookup
+  LDFLAGS+=-Wl,-undefined,dynamic_lookup
 endif
diff --git a/tools/clang/plugins/Makefile b/tools/clang/plugins/Makefile
index 0cfec71..98ce28b 100644
--- a/tools/clang/plugins/Makefile
+++ b/tools/clang/plugins/Makefile
@@ -15,5 +15,5 @@ SHARED_LIBRARY = 1
 include $(CLANG_LEVEL)/Makefile
 
 ifeq ($(OS),Darwin)
-  LDFLAGS=-Wl,-undefined,dynamic_lookup
+  LDFLAGS+=-Wl,-undefined,dynamic_lookup
 endif
diff --git a/tools/clang/scripts/package.sh b/tools/clang/scripts/package.sh
index ba9d744..93d0780 100755
--- a/tools/clang/scripts/package.sh
+++ b/tools/clang/scripts/package.sh
@@ -100,6 +100,10 @@ cp buildlog.txt $PDIR/
 cp "${LLVM_BIN_DIR}/clang" $PDIR/bin/
 (cd $PDIR/bin && ln -sf clang clang++ && cd -)
 cp "${LLVM_BIN_DIR}/llvm-symbolizer" $PDIR/bin/
+if [ "$(uname -s)" = "Darwin" ]; then
+  cp "${LLVM_BIN_DIR}/libc++.1.${SO_EXT}" $PDIR/bin/
+  (cd $PDIR/bin && ln -sf libc++.1.dylib libc++.dylib && cd -)
+fi
 
 # Copy plugins. Some of the dylibs are pretty big, so copy only the ones we
 # care about.
diff --git a/tools/clang/scripts/update.sh b/tools/clang/scripts/update.sh
index 113905c..e730b24 100755
--- a/tools/clang/scripts/update.sh
+++ b/tools/clang/scripts/update.sh
@@ -19,9 +19,14 @@ CLANG_DIR="${LLVM_DIR}/tools/clang"
 CLANG_TOOLS_EXTRA_DIR="${CLANG_DIR}/tools/extra"
 COMPILER_RT_DIR="${LLVM_DIR}/projects/compiler-rt"
 LIBCXX_DIR="${LLVM_DIR}/projects/libcxx"
+LIBCXXABI_DIR="${LLVM_DIR}/projects/libcxxabi"
 ANDROID_NDK_DIR="${LLVM_DIR}/../android_tools/ndk"
 STAMP_FILE="${LLVM_BUILD_DIR}/cr_build_revision"
 
+ABS_LIBCXX_DIR="${PWD}/${LIBCXX_DIR}"
+ABS_LIBCXXABI_DIR="${PWD}/${LIBCXXABI_DIR}"
+
+
 # Use both the clang revision and the plugin revisions to test for updates.
 BLINKGCPLUGIN_REVISION=\
 $(grep LIBRARYNAME "$THIS_DIR"/../blink_gc_plugin/Makefile \
@@ -276,6 +281,14 @@ if [ "${OS}" = "Darwin" ]; then
                  "${LIBCXX_DIR}"
 fi
 
+# While we're bundling our own libc++ on OS X, we need to compile libc++abi
+# into it too (since OS X 10.6 doesn't have libc++abi.dylib either).
+if [ "${OS}" = "Darwin" ]; then
+  echo Getting libc++abi r"${CLANG_REVISION}" in "${LIBCXXABI_DIR}"
+  svn co --force "${LLVM_REPO_URL}/libcxxabi/trunk@${CLANG_REVISION}" \
+                 "${LIBCXXABI_DIR}"
+fi
+
 # Apply patch for test failing with --disable-pthreads (llvm.org/PR11974)
 cd "${CLANG_DIR}"
 svn revert test/Index/crash-recovery-modules.m
@@ -957,12 +970,15 @@ export CXXFLAGS=""
 # needed, on OS X it requires libc++. clang only automatically links to libc++
 # when targeting OS X 10.9+, so add stdlib=libc++ explicitly so clang can run on
 # OS X versions as old as 10.7.
-# TODO(thakis): Enable this once all bots are on 10.7, and remove the
-# --disable-compiler-version-checks flags below, and change all
-# MACOSX_DEPLOYMENT_TARGET values to 10.7.
+# TODO(thakis): Some bots are still on 10.6, so for now bundle libc++.dylib.
+# Remove this once all bots are on 10.7+, then use --enable-libcpp=yes and
+# change all MACOSX_DEPLOYMENT_TARGET values to 10.7.
 if [ "${OS}" = "Darwin" ]; then
-  #CXXFLAGS="-stdlib=libc++"
-  CXXFLAGS="-std=gnu++98"
+  # When building on 10.9, /usr/include usually doesn't exist, and while
+  # Xcode's clang automatically sets a sysroot, self-built clangs don't.
+  export CFLAGS="-isysroot $(xcrun --show-sdk-path)"
+  export CPPFLAGS="${CFLAGS}"
+  export CXXFLAGS="-stdlib=libc++ -nostdinc++ -I${ABS_LIBCXX_DIR}/include ${CFLAGS}"
 fi
 
 # Build bootstrap clang if requested.
@@ -977,7 +993,6 @@ if [[ -n "${bootstrap}" ]]; then
     # compiler should be as similar to the final compiler as possible, so do
     # keep --disable-threads & co.
     ../llvm/configure \
-        --disable-compiler-version-checks \
         --enable-optimized \
         --enable-targets=host-only \
         --enable-libedit=no \
@@ -988,12 +1003,12 @@ if [[ -n "${bootstrap}" ]]; then
         --prefix="${ABS_INSTALL_DIR}"
   fi
 
-  MACOSX_DEPLOYMENT_TARGET=10.5 ${MAKE} -j"${NUM_JOBS}"
+  ${MAKE} -j"${NUM_JOBS}"
   if [[ -n "${run_tests}" ]]; then
     ${MAKE} check-all
   fi
 
-  MACOSX_DEPLOYMENT_TARGET=10.5 ${MAKE} install
+  ${MAKE} install
   if [[ -n "${gcc_toolchain}" ]]; then
     # Copy that gcc's stdlibc++.so.6 to the build dir, so the bootstrap
     # compiler can start.
@@ -1019,10 +1034,39 @@ fi
 # The clang bots have this path hardcoded in built/scripts/slave/compile.py,
 # so if you change it you also need to change these links.
 mkdir -p "${LLVM_BUILD_DIR}"
-cd "${LLVM_BUILD_DIR}"
+pushd "${LLVM_BUILD_DIR}"
+
+# Build libc++.dylib while some bots are still on OS X 10.6.
+if [ "${OS}" = "Darwin" ]; then
+  rm -rf libcxxbuild
+  LIBCXXFLAGS="-O3 -std=c++11 -fstrict-aliasing"
+
+  # libcxx and libcxxabi both have a file stdexcept.cpp, so put their .o files
+  # into different subdirectories.
+  mkdir -p libcxxbuild/libcxx
+  pushd libcxxbuild/libcxx
+  c++ -c ${CXXFLAGS} ${LIBCXXFLAGS} "${ABS_LIBCXX_DIR}"/src/*.cpp
+  popd
+
+  mkdir -p libcxxbuild/libcxxabi
+  pushd libcxxbuild/libcxxabi
+  c++ -c ${CXXFLAGS} ${LIBCXXFLAGS} "${ABS_LIBCXXABI_DIR}"/src/*.cpp -I"${ABS_LIBCXXABI_DIR}/include"
+  popd
+
+  pushd libcxxbuild
+  cc libcxx/*.o libcxxabi/*.o -o libc++.1.dylib -dynamiclib -nodefaultlibs \
+    -current_version 1 -compatibility_version 1 \
+    -lSystem -install_name @executable_path/libc++.dylib \
+    -Wl,-unexported_symbols_list,${ABS_LIBCXX_DIR}/lib/libc++unexp.exp \
+    -Wl,-force_symbols_not_weak_list,${ABS_LIBCXX_DIR}/lib/notweak.exp \
+    -Wl,-force_symbols_weak_list,${ABS_LIBCXX_DIR}/lib/weak.exp
+  ln -sf libc++.1.dylib libc++.dylib
+  popd
+  export LDFLAGS+="-stdlib=libc++ -L${PWD}/libcxxbuild"
+fi
+
 if [[ ! -f ./config.status ]]; then
   ../llvm/configure \
-      --disable-compiler-version-checks \
       --enable-optimized \
       --enable-libedit=no \
       --disable-threads \
@@ -1042,9 +1086,11 @@ STRIP_FLAGS=
 if [ "${OS}" = "Darwin" ]; then
   # See http://crbug.com/256342
   STRIP_FLAGS=-x
+
+  cp libcxxbuild/libc++.1.dylib Release+Asserts/bin
 fi
 strip ${STRIP_FLAGS} Release+Asserts/bin/clang
-cd -
+popd
 
 if [[ -n "${with_android}" ]]; then
   # Make a standalone Android toolchain.