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

tools/clang/scripts/update.sh

 #!/usr/bin/env bash
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script will check out llvm and clang into third_party/llvm and build it.
 
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
 CLANG_REVISION=202554
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"
 LLVM_BUILD_DIR="${LLVM_DIR}/../llvm-build"
 LLVM_BOOTSTRAP_DIR="${LLVM_DIR}/../llvm-bootstrap"
 LLVM_BOOTSTRAP_INSTALL_DIR="${LLVM_DIR}/../llvm-bootstrap-install"
 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 \
     | cut -d '_' -f 2)
 CLANG_AND_PLUGINS_REVISION="${CLANG_REVISION}-${BLINKGCPLUGIN_REVISION}"
 
 # ${A:-a} returns $A if it's set, a else.
 LLVM_REPO_URL=${LLVM_URL:-https://llvm.org/svn/llvm-project}
 
 if [[ -z "$GYP_DEFINES" ]]; then
@@ skipping 234 matching lines @@
                "${COMPILER_RT_DIR}"
 
 # clang needs a libc++ checkout, else -stdlib=libc++ won't find includes
 # (i.e. this is needed for bootstrap builds).
 if [ "${OS}" = "Darwin" ]; then
   echo Getting libc++ r"${CLANG_REVISION}" in "${LIBCXX_DIR}"
   svn co --force "${LLVM_REPO_URL}/libcxx/trunk@${CLANG_REVISION}" \
                  "${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
 cat << 'EOF' |
 --- third_party/llvm/tools/clang/test/Index/crash-recovery-modules.m    (revision 202554)
 +++ third_party/llvm/tools/clang/test/Index/crash-recovery-modules.m    (working copy)
 @@ -12,6 +12,8 @@
  
  // REQUIRES: crash-recovery
  // REQUIRES: shell
@@ skipping 661 matching lines @@
   export CC="$gcc_toolchain/bin/gcc"
   export CXX="$gcc_toolchain/bin/g++"
 fi
 
 export CFLAGS=""
 export CXXFLAGS=""
 # LLVM uses C++11 starting in llvm 3.5. On Linux, this means libstdc++4.7+ is
 # 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.
 if [[ -n "${bootstrap}" ]]; then
   ABS_INSTALL_DIR="${PWD}/${LLVM_BOOTSTRAP_INSTALL_DIR}"
   echo "Building bootstrap compiler"
   mkdir -p "${LLVM_BOOTSTRAP_DIR}"
   cd "${LLVM_BOOTSTRAP_DIR}"
   if [[ ! -f ./config.status ]]; then
     # The bootstrap compiler only needs to be able to build the real compiler,
     # so it needs no cross-compiler output support. In general, the host
     # compiler should be as similar to the final compiler as possible, so do
     # keep --disable-threads & co.
     ../llvm/configure \
-        --disable-compiler-version-checks \
         --enable-optimized \
         --enable-targets=host-only \
         --enable-libedit=no \
         --disable-threads \
         --disable-pthreads \
         --without-llvmgcc \
         --without-llvmgxx \
         --prefix="${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.
     cp -v "$(${CXX} -print-file-name=libstdc++.so.6)" \
       "${ABS_INSTALL_DIR}/lib/"
   fi
 
   cd -
   export CC="${ABS_INSTALL_DIR}/bin/clang"
   export CXX="${ABS_INSTALL_DIR}/bin/clang++"
 
   if [[ -n "${gcc_toolchain}" ]]; then
     # Tell the bootstrap compiler to use a specific gcc prefix to search
     # for standard library headers and shared object file.
     export CFLAGS="--gcc-toolchain=${gcc_toolchain}"
     export CXXFLAGS="--gcc-toolchain=${gcc_toolchain}"
   fi
 
   echo "Building final compiler"
 fi
 
 # Build clang (in a separate directory).
 # 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.

[hans, 2014/04/01 15:59:19]

i never built libc++, but i assume its build system doesn't work for us since it
looks like you're hand rolling the compilation below?

[Nico, 2014/04/01 18:26:18]

libc++'s build system is a shell script called "buildit" that roughly does "cc
-c src/*.cpp" with the flags I'm using here. (There's now a cmake build of it,
but not of libc++abi as far as I know, and I need to link both libc++ and
libc++abi into the same dylib. libc++'s buildit uses a "reexport symbols" trick
for this, but that trick doesn't work when targeting older os x versions.)

+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 \
       --disable-pthreads \
       --without-llvmgcc \
       --without-llvmgxx
 fi
 
 if [[ -n "${gcc_toolchain}" ]]; then
   # Copy in the right stdlibc++.so.6 so clang can start.
   mkdir -p Release+Asserts/lib
   cp -v "$(${CXX} ${CXXFLAGS} -print-file-name=libstdc++.so.6)" \
     Release+Asserts/lib/
 fi
 MACOSX_DEPLOYMENT_TARGET=10.5 ${MAKE} -j"${NUM_JOBS}"
 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.
   ${ANDROID_NDK_DIR}/build/tools/make-standalone-toolchain.sh \
       --platform=android-14 \
       --install-dir="${LLVM_BUILD_DIR}/android-toolchain" \
       --system=linux-x86_64 \
       --stl=stlport
 
   # Build ASan runtime for Android.
@@ skipping 29 matching lines @@
       "${TOOL_SRC_DIR}/tests/test.sh" "${LLVM_BUILD_DIR}/Release+Asserts"
     fi
   done
   cd "${LLVM_BUILD_DIR}"
   ${MAKE} check-all
   cd -
 fi
 
 # After everything is done, log success for this revision.
 echo "${CLANG_AND_PLUGINS_REVISION}" > "${STAMP_FILE}"