llvm-orc-jit: add build-llvm.sh, enforce find_package success, and print used llvm/clang cmake config

1 files changed, 50 insertions, 0 deletions

diff --git a/content/2022-07-07-llvm-orc-jit/build-llvm.sh b/content/2022-07-07-llvm-orc-jit/build-llvm.sh
new file mode 100644
index 0000000..df9d6b8
--- /dev/null
+++ b/content/2022-07-07-llvm-orc-jit/build-llvm.sh
@@ -0,0 +1,50 @@
+#!/bin/bash
+#
+# A small utility script to help me build specific llvm versions.
+#
+# ## General cmake build info
+#
+#    See [1] for an overview of the llvm cmake build and a discussion of the most
+#    frequently used cmake options.
+#
+# ## Building on low end machines
+#
+#    Builds with debug information can use a lot of RAM and disk space and is
+#    usually slower to run. You can improve RAM usage by using lld, see the
+#    LLVM_USE_LINKER option.
+#
+#    LLVM_PARALLEL_{COMPILE,LINK}_JOBS:STRING [2]
+#       Building the llvm toolchain can use a lot of resources, particularly
+#       linking. These options, when you use the Ninja generator, allow you to
+#       restrict the parallelism. For example, to avoid OOMs or going into swap,
+#       permit only one link job per 15GB of RAM available on a 32GB machine,
+#       specify -G Ninja -DLLVM_PARALLEL_LINK_JOBS=2.
+#
+# [1]: https://llvm.org/docs/CMake.html
+# [2]: https://llvm.org/docs/CMake.html#frequently-used-llvm-related-variables
+
+#TAG=llvmorg-14.0.6
+#TAG=llvmorg-15.0.0
+#TAG=llvmorg-15.0.7
+TAG=llvmorg-17.0.5
+
+SRCDIR=src-$TAG
+
+if [[ ! -d $SRCDIR ]]; then
+    git clone --depth 1 --branch $TAG https://github.com/llvm/llvm-project.git $SRCDIR
+fi
+
+cmake -S $SRCDIR/llvm -B $SRCDIR/BUILD -G Ninja \
+    -DCMAKE_C_COMPILER=clang \
+    -DCMAKE_CXX_COMPILER=clang++ \
+    -DCMAKE_INSTALL_PREFIX=$PWD/install-$TAG \
+    -DCMAKE_BUILD_TYPE=Debug \
+    -DLLVM_ENABLE_PROJECTS='clang' \
+    -DLLVM_BUILD_LLVM_DYLIB=1 \
+    -DLLVM_ENABLE_ASSERTIONS=ON \
+    -DLLVM_INCLUDE_TESTS=OFF \
+    -DLLVM_TARGETS_TO_BUILD='X86' \
+    -DLLVM_USE_LINKER=lld \
+    -DLLVM_PARALLEL_LINK_JOBS=1
+
+cmake --build $SRCDIR/BUILD --target install