Azure CI: Build LDC itself with full LTO, on Linux and Mac too (#3236)

.azure-pipelines/posix.yml

@@ -21,6 +21,10 @@ steps:
         git-core cmake ninja-build g++-multilib \
         libcurl3 libcurl3:i386 \
         curl gdb tzdata unzip zip
+      # Download & extract clang
+      curl -L -o clang.tar.xz http://releases.llvm.org/9.0.0/clang+llvm-9.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz
+      mkdir clang
+      tar -xf clang.tar.xz --strip 1 -C clang
       # Use ld.gold per default, so that LTO is tested
       sudo update-alternatives --install /usr/bin/ld ld /usr/bin/ld.gold 99
     fi
@@ -73,16 +77,22 @@ steps:
     set -ex
     cd ..
     export PATH="$PWD/ninja:$PATH" # for macOS
+    # Linux: use clang instead of gcc, for LTO
+    if [ "$CI_OS" = "linux" ]; then
+      export CC=$PWD/clang/bin/clang
+      export CXX=$PWD/clang/bin/clang++
+    fi
     installDir=$PWD/install
     mkdir build
     cd build
+    IFS=$'\n' extraFlags=( $(xargs -n1 <<<"$EXTRA_CMAKE_FLAGS") )
     cmake -G Ninja $BUILD_SOURCESDIRECTORY \
       -DCMAKE_BUILD_TYPE=Release \
       -DLLVM_ROOT_DIR=$PWD/../llvm \
       -DD_COMPILER=$PWD/../bootstrap-ldc/bin/ldmd2 \
       -DCMAKE_INSTALL_PREFIX=$installDir \
       -DINCLUDE_INSTALL_DIR=$installDir/import \
-      $EXTRA_CMAKE_FLAGS
+      "${extraFlags[@]}"
     ninja -j$PARALLEL_JOBS all ldc2-unittest all-test-runners
     bin/ldc2 -version
   displayName: Build LDC & LDC D unittests & defaultlib unittest runners
@@ -126,11 +136,12 @@ steps:
 - script: |
     set -ex
     cd ..
+    IFS=$'\n' extraFlags=( $(xargs -n1 <<<"$EXTRA_CMAKE_FLAGS") )
     bootstrap-ldc/bin/ldc-build-runtime --ninja -j $PARALLEL_JOBS \
       --dFlags="${DFLAGS// /;}" \
       --targetSystem='Android;Linux;UNIX' \
       --ldcSrcDir=$BUILD_SOURCESDIRECTORY \
-      ${EXTRA_CMAKE_FLAGS//-D/}
+      "${extraFlags[@]//-D/}"
   displayName: 'Android: Cross-compile default libraries'
   condition: and(succeeded(), eq(variables['CI_OS'], 'android'))
 - script: |
@@ -141,6 +152,7 @@ steps:
     cd build-$ARCH
     DEFAULT_LDC_SWITCHES=' "-linker=bfd",'
     if [ "$ARCH" = "armv7a" ]; then DEFAULT_LDC_SWITCHES="$DEFAULT_LDC_SWITCHES \"-mcpu=cortex-a8\","; fi
+    IFS=$'\n' extraFlags=( $(xargs -n1 <<<"$EXTRA_CMAKE_FLAGS") )
     cmake -G Ninja $BUILD_SOURCESDIRECTORY \
       -DCMAKE_BUILD_TYPE=Release \
       -DLLVM_ROOT_DIR=$PWD/../llvm-$ARCH \
@@ -149,7 +161,7 @@ steps:
       -DINCLUDE_INSTALL_DIR=$installDir/import \
       -DD_LINKER_ARGS="-fuse-ld=bfd;-L$PWD/../ldc-build-runtime.tmp/lib;-lphobos2-ldc;-ldruntime-ldc" \
       -DADDITIONAL_DEFAULT_LDC_SWITCHES="$DEFAULT_LDC_SWITCHES" \
-      $EXTRA_CMAKE_FLAGS
+      "${extraFlags[@]}"
     ninja -j$PARALLEL_JOBS -v ldc2 ldmd2 ldc-build-runtime ldc-profdata ldc-prune-cache
   displayName: 'Android: Cross-compile LDC executables'
   condition: and(succeeded(), eq(variables['CI_OS'], 'android'))

azure-pipelines.yml

@@ -110,7 +110,8 @@ jobs:
     # To improve portability of the generated binaries, link the C++ standard library statically.
     # Also don't use relax relocations for the C(++) parts of the default libraries in order to
     # support older user binutils (e.g., Ubuntu 14.04).
-    EXTRA_CMAKE_FLAGS: -DMULTILIB=ON -DBUILD_LTO_LIBS=ON -DCMAKE_EXE_LINKER_FLAGS=-static-libstdc++ -DRT_CFLAGS=-Wa,-mrelax-relocations=no -DLDC_INSTALL_LTOPLUGIN=ON -DLDC_INSTALL_LLVM_RUNTIME_LIBS=ON
+    BOOTSTRAP_CMAKE_FLAGS: -DBUILD_LTO_LIBS=ON -DLDC_INSTALL_LTOPLUGIN=ON
+    EXTRA_CMAKE_FLAGS: -DMULTILIB=ON -DBUILD_LTO_LIBS=ON -DCMAKE_EXE_LINKER_FLAGS=-static-libstdc++ -DRT_CFLAGS=-Wa,-mrelax-relocations=no -DLDC_INSTALL_LTOPLUGIN=ON -DLDC_INSTALL_LLVM_RUNTIME_LIBS=ON -DD_COMPILER_FLAGS="-flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto" -DEXTRA_CXXFLAGS=-flto=full
   steps:
     - template: .azure-pipelines/posix.yml
 
@@ -121,7 +122,8 @@ jobs:
   variables:
     CI_OS: osx
     ARCH: x86_64
-    EXTRA_CMAKE_FLAGS: -DBUILD_LTO_LIBS=ON
+    BOOTSTRAP_CMAKE_FLAGS: -DBUILD_LTO_LIBS=ON
+    EXTRA_CMAKE_FLAGS: -DBUILD_LTO_LIBS=ON -DD_COMPILER_FLAGS="-flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto" -DEXTRA_CXXFLAGS=-flto=full
     MACOSX_DEPLOYMENT_TARGET: 10.9
   steps:
     - template: .azure-pipelines/posix.yml

driver/linker-gcc.cpp

@@ -169,8 +169,7 @@ std::string getLTOdylibPath() {
 void ArgsBuilder::addDarwinLTOFlags() {
   std::string dylibPath = getLTOdylibPath();
   if (!dylibPath.empty()) {
-    args.push_back("-lto_library");
-    args.push_back(std::move(dylibPath));
+    addLdFlag("-lto_library", dylibPath);
   }
 }