Make building Python bindings optional (#1926)

Many developers are using the ci_build_* scripts to build LLVM and
StableHLO.

A previous PR #1923 made the CI system by default building python
bindings however there is an undocumented step of installing Python
dependencies such as pybind.

To simplify local development, make the option configurable with the
default to OFF so that the ci_build_* actions work without any
additional setup.

The CI system itself (GitHub actions) set the appropriate variables to
build the Python bindings.

.github/workflows/buildAndTestCMake.yml

@@ -70,8 +70,14 @@ jobs:
       shell: bash
       run: |
         ./build_tools/github_actions/ci_build_cmake_llvm.sh "$LLVM_PROJECT_DIR" "$LLVM_BUILD_DIR"
+      env:
+          CMAKE_BUILD_TYPE: Release
+          MLIR_ENABLE_BINDINGS_PYTHON: ON
 
     - name: Build and Test StableHLO (with Python bindings)
       shell: bash
       run: |
-        ./build_tools/github_actions/ci_build_cmake.sh "$LLVM_BUILD_DIR" "$STABLEHLO_BUILD_DIR"
+        ./build_tools/github_actions/ci_build_cmake.sh "$LLVM_BUILD_DIR" "$STABLEHLO_BUILD_DIR"
+      env:
+          CMAKE_BUILD_TYPE: Release
+          STABLEHLO_ENABLE_BINDINGS_PYTHON: ON

build_tools/github_actions/ci_build_cmake.sh

@@ -27,21 +27,25 @@ fi
 
 LLVM_BUILD_DIR="$1"
 STABLEHLO_BUILD_DIR="$2"
+CMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE:-RelWithDebInfo}"
+
+# Turn on building Python bindings
+STABLEHLO_ENABLE_BINDINGS_PYTHON="${STABLEHLO_ENABLE_BINDINGS_PYTHON:-OFF}"
 
 # Configure StableHLO
 cmake -GNinja \
   -B"$STABLEHLO_BUILD_DIR" \
   -DLLVM_ENABLE_LLD=ON \
-  -DCMAKE_BUILD_TYPE=Release \
+  -DCMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE}" \
   -DLLVM_ENABLE_ASSERTIONS=ON \
   -DMLIR_DIR="$LLVM_BUILD_DIR/lib/cmake/mlir" \
   -DCMAKE_CXX_COMPILER=clang++ \
   -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
   -DCMAKE_C_COMPILER=clang \
   -DCMAKE_C_COMPILER_LAUNCHER=ccache \
   -DSTABLEHLO_ENABLE_STRICT_BUILD=ON \
-  -DSTABLEHLO_ENABLE_BINDINGS_PYTHON=ON
+  -DSTABLEHLO_ENABLE_BINDINGS_PYTHON="${STABLEHLO_ENABLE_BINDINGS_PYTHON}"
 
 # Build and Test StableHLO
-cd "$STABLEHLO_BUILD_DIR"
+cd "$STABLEHLO_BUILD_DIR" || exit
 ninja check-stablehlo-ci

build_tools/github_actions/ci_build_cmake_llvm.sh

@@ -25,6 +25,10 @@ fi
 LLVM_SRC_DIR="$1"
 LLVM_BUILD_DIR="$2"
 
+CMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE:-RelWithDebInfo}"
+# Turn on building Python bindings
+MLIR_ENABLE_BINDINGS_PYTHON="${MLIR_ENABLE_BINDINGS_PYTHON:-OFF}"
+
 # Configure LLVM
 cmake -GNinja \
   "-H$LLVM_SRC_DIR/llvm" \
@@ -34,11 +38,11 @@ cmake -GNinja \
   -DLLVM_ENABLE_PROJECTS=mlir \
   -DLLVM_TARGETS_TO_BUILD=host \
   -DLLVM_INCLUDE_TOOLS=ON \
-  -DMLIR_ENABLE_BINDINGS_PYTHON=ON \
+  -DMLIR_ENABLE_BINDINGS_PYTHON="${MLIR_ENABLE_BINDINGS_PYTHON}" \
   -DLLVM_ENABLE_BINDINGS=OFF \
   -DLLVM_BUILD_TOOLS=OFF \
   -DLLVM_INCLUDE_TESTS=OFF \
-  -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+  -DCMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE}" \
   -DLLVM_ENABLE_ASSERTIONS=On \
   -DCMAKE_CXX_COMPILER=clang++ \
   -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \