build-tblgen.sh

#!/usr/bin/env bash
#
# Build the Linux/Mac llvm-tblgen tool. Note that this will be run during the
# Linux/Mac coredistools build. So, we only build the versions that we'll use
# during those builds. Thus, we need a linux-x64 version (used for
# linux-x64, linux-arm, linux-arm64 builds) and osx-x64 version (used for
# osx-x64 and osx-arm64 builds).

set -x

TargetOSArchitecture=$1
CrossRootfsDirectory=$2

# Set this to 1 to build using Azure Linux
BuildUsingAzureLinux=1

CMakeOSXArchitectures=
LLVMTargetsToBuild="AArch64;ARM;X86;LoongArch;RISCV"

case "$TargetOSArchitecture" in
    linux-x64)
        LLVMHostTriple=x86_64-linux-gnu
        ;;

    linux-loongarch64)
        LLVMHostTriple=loongarch64-linux-gnu
        LLVMTargetsToBuild="LoongArch"
        ;;

    osx-x64)
        CMakeOSXArchitectures=x86_64
        LLVMHostTriple=x86_64-apple-darwin
        BuildUsingAzureLinux=0
        ;;

    *)
        echo "Unknown target OS and architecture: $TargetOSArchitecture"
        exit 1
esac

RootDirectory="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
SourcesDirectory=$RootDirectory/src
BinariesDirectory=$RootDirectory/obj
StagingDirectory=$RootDirectory/bin

command -v cmake >/dev/null 2>&1

if [ "$?" -ne 0 ]; then
    echo "ERROR: cmake is not found in the PATH"
    exit 1
fi

if [ ! -d $BinariesDirectory ]; then
    mkdir -p $BinariesDirectory
fi

pushd "$BinariesDirectory"

# Take first match from: clang clang-20 clang-19 .. clang-15
C_COMPILER=$(command -v clang{,-{20..15}} | head -n 1)
CXX_COMPILER=$(command -v clang++{,-{20..15}} | head -n 1)

echo "============== Configuring build"
if [ $BuildUsingAzureLinux -eq 1 ]; then
    C_BUILD_FLAGS=""
    CXX_BUILD_FLAGS=""
    # Azure Linux doesn't have `ld` so need to tell clang to use `lld` with "-fuse-ld=lld"
    cmake \
        -G "Unix Makefiles" \
        -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_ASM_COMPILER=$C_COMPILER \
        -DCMAKE_C_COMPILER=$C_COMPILER \
        -DCMAKE_CXX_COMPILER=$CXX_COMPILER \
        -DCMAKE_ASM_COMPILER_TARGET="$LLVMHostTriple" \
        -DCMAKE_C_COMPILER_TARGET="$LLVMHostTriple" \
        -DCMAKE_CXX_COMPILER_TARGET="$LLVMHostTriple" \
        -DCMAKE_C_FLAGS="${C_BUILD_FLAGS}" \
        -DCMAKE_CXX_FLAGS="${CXX_BUILD_FLAGS}" \
        -DCMAKE_INSTALL_PREFIX=$RootDirectory \
        -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
        -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld" \
        -DCMAKE_SHARED_LINKER_FLAGS="-fuse-ld=lld" \
        -DLLVM_USE_LINKER=lld \
        -DLLVM_ENABLE_RUNTIMES="libcxx" \
        -DLIBCXX_ENABLE_SHARED=OFF \
        -DLIBCXX_CXX_ABI=libstdc++ \
        -DLIBCXX_CXX_ABI_INCLUDE_PATHS="$CPP_INCLUDES;$TRIPLET_INCLUDES" \
        -DLLVM_TARGETS_TO_BUILD=$LLVMTargetsToBuild \
        $SourcesDirectory/llvm-project/llvm
elif [ -z "$CrossRootfsDirectory" ]; then
    BUILD_FLAGS=""
    cmake \
        -G "Unix Makefiles" \
        -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_SYSTEM_NAME=$CMakeSystemName \
        -DCMAKE_C_COMPILER=$C_COMPILER \
        -DCMAKE_CXX_COMPILER=$CXX_COMPILER \
        -DCMAKE_C_FLAGS="${BUILD_FLAGS}" \
        -DCMAKE_CXX_FLAGS="${BUILD_FLAGS}" \
        -DCMAKE_INSTALL_PREFIX=$RootDirectory \
        -DCMAKE_OSX_ARCHITECTURES=$CMakeOSXArchitectures \
        -DLLVM_TARGETS_TO_BUILD=$LLVMTargetsToBuild \
        $SourcesDirectory/llvm-project/llvm
else
    BUILD_FLAGS="--sysroot=$CrossRootfsDirectory"
    cmake \
        -G "Unix Makefiles" \
        -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_INSTALL_PREFIX=$RootDirectory \
        -DCMAKE_SYSTEM_NAME=$CMakeSystemName \
        -DCMAKE_C_COMPILER=$C_COMPILER \
        -DCMAKE_CXX_COMPILER=$CXX_COMPILER \
        -DCMAKE_C_FLAGS="${BUILD_FLAGS}" \
        -DCMAKE_CXX_FLAGS="${BUILD_FLAGS}" \
        -DCMAKE_INCLUDE_PATH=$CrossRootfsDirectory/usr/include \
        -DCMAKE_LIBRARY_PATH=$CrossRootfsDirectory/usr/lib/$LLVMHostTriple \
        -DLLVM_TARGETS_TO_BUILD=$LLVMTargetsToBuild \
        $SourcesDirectory/llvm-project/llvm
fi

popd

if [ "$?" -ne 0 ]; then
    echo "ERROR: cmake exited with code $?"
    exit 1
fi

echo "============== Building llvm-tblgen"
cmake \
    --build $BinariesDirectory \
    --parallel 4 \
    --target llvm-tblgen \
    --config Release

if [ "$?" -ne 0 ]; then
    echo "ERROR: cmake exited with code $?"
    exit 1
fi

if [ ! -d $StagingDirectory ]; then
    mkdir -p $StagingDirectory
fi

# Copy llvm-tblgen from BinariesDirectory to StagingDirectory
find $BinariesDirectory -name llvm-tblgen -type f -exec cp -v {} $StagingDirectory \;

exit 0