DRAFT: [standalone-build] fix ccache, enable lit tests, and use proper cmake prefix path

[kwk]

Summary

See also:

https://reviews.llvm.org/D141050
https://discourse.llvm.org/t/an-opinionated-way-to-outsource-simplify-and-unify-repetitive-cmake-code-in-standalone-build-mode/67508

zorg/buildbot/builders/annotated/standalone-build.sh

build_python_lit() {
     
     build_step "Sparse checkout out python-lit"
     git -C "${LLVM_ROOT}" sparse-checkout set llvm/utils/lit
 
     build_step "Building python-lit"
     cd "${LLVM_ROOT}"/llvm/utils/lit
     python3 setup.py build '--executable=/usr/bin/python3 -s'
 
-    # TODO(kkleine): Fix failing test: FAIL: lit :: shtest-not.py (43 of 50)
-    #build_step "Testing python-lit"
-    #python3 lit.py tests
+    build_step "Testing python-lit"
+    python3 lit.py tests
 
     build_step "Installing python-lit"
     rm -rf ${PYTHON_LIT_INSTALL_DIR}
     python3 setup.py install -O1 --skip-build --root ${PYTHON_LIT_INSTALL_DIR}
     
     build_step "Removing python-lit build dir"
     rm -rf ${PYTHON_LIT_BUILD_DIR}
 
build_llvm() {
     cmake ${CMAKE_TRACE_CONFIGURE_LLVM} \
         -S ${LLVM_ROOT}/llvm \
         -B ${LLVM_BUILD_DIR} \
         -G Ninja \
         -DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
         -DLLVM_BUILD_LLVM_DYLIB=ON \
         -DLLVM_LINK_LLVM_DYLIB=ON \
         -DLLVM_INCLUDE_BENCHMARKS=OFF \
-        -DLLVM_INSTALL_UTILS=ON \
         -DCMAKE_INSTALL_PREFIX=${LLVM_INSTALL_DIR} \
         -DLLVM_EXTERNAL_LIT=${PYTHON_LIT_INSTALL_DIR}/usr/local/bin/lit \
         -DLLVM_INCLUDE_UTILS:BOOL=ON \
         -DLLVM_INSTALL_UTILS:BOOL=ON \
         -DLLVM_UTILS_INSTALL_DIR:PATH=${LLVM_INSTALL_DIR}/bin \
         -DLLVM_CCACHE_BUILD=ON
 
     build_step "Building llvm"
build_clang() {
     build_step "Configuring clang"
     cmake ${CMAKE_TRACE_CONFIGURE_CLANG} \
         -S ${LLVM_ROOT}/clang \
         -B ${CLANG_BUILD_DIR} \
         -G Ninja \
         -DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
         -DCLANG_LINK_CLANG_DYLIB=ON \
         -DCLANG_INCLUDE_TESTS=ON \
-        -DLLVM_EXTERNAL_LIT=${PYTHON_LIT_INSTALL_DIR}/usr/local/bin/lit \
         -DCMAKE_INSTALL_PREFIX=${CLANG_INSTALL_DIR} \
         -DLLVM_ROOT=${LLVM_INSTALL_DIR} \
         -DLLVM_ENABLE_ASSERTIONS=ON \
-        -DLLVM_TABLEGEN_EXE=${LLVM_INSTALL_DIR}/bin/llvm-tblgen \
-        -DLLVM_CCACHE_BUILD=ON
+        -DCMAKE_PREFIX_PATH=${LLVM_INSTALL_DIR}/lib/cmake/llvm \
+        -DLLVM_EXTERNAL_LIT=${PYTHON_LIT_INSTALL_DIR}/usr/local/bin/lit \
+        -DCMAKE_C_COMPILER_LAUNCHER="ccache" \
+        -DCMAKE_CXX_COMPILER_LAUNCHER="ccache"
 
     build_step "Building clang"
     LD_LIBRARY_PATH="${LLVM_INSTALL_DIR}/lib64" cmake --build ${CLANG_BUILD_DIR} ${CMAKE_VERBOSE_BUILD_CLANG}
 
-    # TODO(kwk): Add Clang check
+    build_step "Testing clang"
+    LD_LIBRARY_PATH="${LLVM_INSTALL_DIR}/lib64" cmake --build ${CLANG_BUILD_DIR} --target check-clang ${CMAKE_VERBOSE_CHECK_CLANG}
 
     build_step "Installing clang"
     rm -rf ${CLANG_INSTALL_DIR}
     cmake --install ${CLANG_BUILD_DIR} ${CMAKE_VERBOSE_INSTALL_CLANG}
 
     build_step "Removing clang build dir"
     rm -rf ${CLANG_BUILD_DIR}
 }
build_lld() {
     cmake ${CMAKE_TRACE_CONFIGURE_LLD} \
         -S ${LLVM_ROOT}/lld \
         -B ${LLD_BUILD_DIR} \
         -G Ninja \
         -DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
         -DLLVM_LINK_LLVM_DYLIB=ON \
         -DCMAKE_INSTALL_PREFIX=${LLD_INSTALL_DIR} \
         -DLLVM_ROOT=${LLVM_INSTALL_DIR} \
-        -DLLVM_CCACHE_BUILD=ON \
         -DLLVM_INCLUDE_TESTS=ON \
-        -DLLVM_EXTERNAL_LIT=${PYTHON_LIT_INSTALL_DIR}/usr/local/bin/lit
+        -DLLVM_EXTERNAL_LIT=${PYTHON_LIT_INSTALL_DIR}/usr/local/bin/lit \
+        -DCMAKE_PREFIX_PATH=${LLVM_INSTALL_DIR}/lib/cmake/llvm \
+        -DCMAKE_C_COMPILER_LAUNCHER="ccache" \
+        -DCMAKE_CXX_COMPILER_LAUNCHER="ccache"
 
     build_step "Building lld"
     LD_LIBRARY_PATH="${LLVM_INSTALL_DIR}/lib64" cmake --build ${LLD_BUILD_DIR} ${CMAKE_VERBOSE_BUILD_LLD}
 
     build_step "Testing lld"
     LD_LIBRARY_PATH="${LLVM_INSTALL_DIR}/lib64" cmake --build ${LLD_BUILD_DIR} --target check-lld ${CMAKE_VERBOSE_CHECK_LLD}
 
     build_step "Installing lld"