tree a92b0975fe8df9e8dec5c12aadf6b504cdb87f26
parent 9de48d3b5ed6b6aee744e4585e9d955ee04ac0fc
author Qihan Cai <qcai8733@uni.sydney.edu.au> 1656869709 +1000
committer Than McIntosh <thanm@google.com> 1661518587 +0000

gollvm: add support for crosscompiling

Add support for compiling gollvm for other arch by specifying GOLLVM_DRIVER_DIR to a prebuilt gollvm with two targets, and specify target, toolchain and sysroot in GOLLVM_EXTRA_GOCFLAGS.

Example usage:
RISCV=$HOME/toolchain
SOURCE=$HOME/llvm-project/llvm
TRIPLE=riscv64-unknown-linux-gnu

# host
cmake -G Ninja -S $SOURCE -B build-x86 \
    -DCMAKE_INSTALL_PREFIX=install-x86 \
    -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_USE_LINKER=bfd \
    -DGOLLVM_DEFAULT_LINKER=bfd \
    -DLLVM_TARGET_ARCH="X86-64,RISCV64" \
    -DLLVM_TARGETS_TO_BUILD="X86;RISCV"

# crosscompile
cmake -G Ninja -S $SOURCE -B build-riscv \
    -DCMAKE_INSTALL_PREFIX=$INSTALL \
    -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_USE_LINKER=bfd \
    -DGOLLVM_DEFAULT_LINKER=bfd \
    -DCMAKE_CROSSCOMPILING=True \
    -DLLVM_TARGET_ARCH=RISCV64 \
    -DLLVM_DEFAULT_TARGET_TRIPLE=$TRIPLE \
    -DLLVM_TARGETS_TO_BUILD=RISCV \
    -DCMAKE_C_COMPILER=$RISCV/bin/$TRIPLE-gcc \
    -DCMAKE_CXX_COMPILER=$RISCV/bin/$TRIPLE-g++ \
    -DLLVM_TABLEGEN=$PWD/build-x86/bin/llvm-tblgen \
    -DGOLLVM_DRIVER_DIR=$PWD/build-x86/bin \
    -DGOLLVM_EXTRA_GOCFLAGS="--target=$TRIPLE \
                             --gcc-toolchain=$RISCV/ \
                             --sysroot=$RISCV/sysroot" \
    -DGOLLVM_USE_SPLIT_STACK=OFF \
    -DCMAKE_C_FLAGS=-latomic \
    -DCMAKE_CXX_FLAGS=-latomic

 # build gollvm crosscompiler
 ninja -C build-x86 llvm-goc llvm-goc-token llvm-godumpspec

 # cross compile gollvm, go tools and install
 ninja -C build-riscv install-gollvm

Change-Id: Ie4997771fd21437f65d857b7aaae267b7a394f23
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/425199
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>