记录--Mac OSX 使用homebrew安装的LLVM 6.0.0 遇到的问题

Mac OSX 使用homebrew安装的LLVM 6.0.0 遇到的问题

LLVM是用来生成中间代码、开发编译器后端的工具。虽然功能很强大，提供的中间代码格式很清晰，但必须要吐槽一下它的文档……是真的难用，虽然和openCV采用相同的模板，但既缺乏例子，也缺乏内容，只有干干净净的函数声明，大部分详细介绍都是一句话：请参考我们的源代码 sigh

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遇到的错误：

CMakelist里使用find_package无法找到LLVM
Could not find a package configuration file provided by "LLVM" (requested version 5.0.0) with any of the following names:
LLVMConfig.cmake
llvm-config.cmake
Add the installation prefix of "LLVM" to CMAKE_PREFIX_PATH or set "LLVM_DIR" to a directory containing one of the above files. If "LLVM" provides a separate development package or SDK, be sure it has been installed.

LLVM_DIR:PATH=/usr/local/opt/llvm/lib/cmake/llvm

解决方法

在CMakeList中添加：
SET(LLVM_DIR /usr/local/opt/llvm/lib/cmake/llvm)
SET(CMAKE_PREFIX_PATH /usr/local/opt/llvm/lib/cmake/)
注意,在Mac上使用homebrew安装的LLVM存在于两个目录：
/usr/local/Cellar/llvm
以及/usr/local/opt/llvm
刚开始我一直尝试使用第一个目录下的LLVM，但clion一直一直报cmake的错误，后来按上文试试用第二个目录，就正常了。
讲道理，还是Linux配环境方便

附上我用的CMakeList.txt：

CMakeList.txt

cmake_minimum_required(VERSION 2.8)
project(SimplePascalCompiler)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wno-return-type -Wno-c++11-compat-deprecated-writable-strings -Wno-deprecated-register -Wno-switch")

FIND_PACKAGE(BISON REQUIRED)
SET(BisonOutput ${CMAKE_SOURCE_DIR}/parser.cpp)
IF(BISON_FOUND)
    ADD_CUSTOM_COMMAND(
            OUTPUT ${BisonOutput}
            COMMAND ${BISON_EXECUTABLE}
            -d ${CMAKE_SOURCE_DIR}/pascal.y
            -o ${CMAKE_SOURCE_DIR}/parser.cpp
            COMMENT "Generating parser.cpp"
    )
ENDIF()

FIND_PACKAGE(FLEX REQUIRED)
SET(FlexOutput ${CMAKE_SOURCE_DIR}/token.cpp)
IF(FLEX_FOUND)
    ADD_CUSTOM_COMMAND(
            OUTPUT ${FlexOutput}
            COMMAND ${FLEX_EXECUTABLE}
            -o ${CMAKE_SOURCE_DIR}/token.cpp ${CMAKE_SOURCE_DIR}/pascal.l
            COMMENT "Generating token.cpp"
    )
ENDIF()

find_package(LLVM 6.0 REQUIRED CONFIG)

message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")

include_directories(${LLVM_INCLUDE_DIRS})
add_definitions(${LLVM_DEFINITIONS})

set(SOURCE_FILES ${FlexOutput} AbstractTree.cpp CodeGenContext.cpp main.cpp errorhandle.cpp)
add_executable(pascal ${SOURCE_FILES} ${BisonOutput})

llvm_map_components_to_libnames(llvm_libs support core irreader)

target_link_libraries(pascal ${llvm_libs})