构建LLVM示例

Question

我正在尝试构建一个来自标准发行版的示例，即BrainF，但没有成功。

我制作了examples/BrainF的副本，并尝试从这个目录运行cmake。最初，CMakeLists.txt看起来像这样：

set(LLVM_LINK_COMPONENTS jit bitwriter nativecodegen interpreter)

add_llvm_example(BrainF
  BrainF.cpp
  BrainFDriver.cpp
  )

cmake抱怨add_*。我通读了http://llvm.org/docs/CMake.html#embedding，并决定为CMakeLists.txt添加一些前奏：

find_package(LLVM)

# Define add_llvm_* macro's.
include(AddLLVM)

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

然后cmake抱怨它不能执行find_package(LLVM)，并建议查找LLVMConfig.cmake或llvm-config.cmake。我在/usr/src/llvm/cmake/modules/LLVM-Config.cmake下找到的最接近的文件，所以我设置了CMAKE_PREFIX_PATH=/usr/src/llvm/cmake/modules/并将LLVMConfig.cmake软链接到LLVM-Config.cmake。

然后cmake这样抱怨：“include找不到加载文件:AddLLVM”。如果我将整个路径硬编码为包含AddLLVM.cmake，那么问题就转到了AddLLVM.cmake中存在的includes上，所以它看起来不像是完成任务的正确方法。

我的环境是xubuntu12.04和Debian 3.1 (从一些llvm+clang得到了deb包，从Debian得到了backport )。

Answer 1

在llvm 11.0。

我试过了，它起作用了。

可能需要使用add_llvm_executable命令才能与LLVM_LINK_COMPONENTS链接

cmake_minimum_required(VERSION 3.4.3)

find_package(LLVM REQUIRED CONFIG)
project(BrainF)

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

include_directories(${LLVM_INCLUDE_DIRS})
add_definitions(${LLVM_DEFINITIONS})
list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")
include(AddLLVM)

set(LLVM_LINK_COMPONENTS
  BitWriter
  Core
  ExecutionEngine
  MC
  MCJIT
  Support
  nativecodegen
  )

add_llvm_executable(BrainF
  BrainF.cpp
  BrainFDriver.cpp
  )

附注：更新。2020.11.1。

more info

cmake_minimum_required(VERSION 3.4.3)
project(BrainF)

find_package(LLVM 11 REQUIRED CONFIG)
add_definitions(${LLVM_DEFINITIONS})
include_directories(${LLVM_INCLUDE_DIRS})

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

add_executable(BrainF
  BrainF.cpp
  BrainFDriver.cpp
)

llvm_map_components_to_libnames(llvm_libs support core irreader)

target_link_libraries(BrainF llvm_libs)

Answer 2

这个帖子帮助我获得了AddLLVM：For the cmake "include" command, what is the difference between a file and a module?

此外，现在在手动设置后，我遇到了问题：“Library` `jit‘not found in list of llvm Library”。error的全文：

$ cmake .
CMake Error at /usr/src/llvm/cmake/modules/LLVM-Config.cmake:141 (message):
  Library `jit' not found in list of llvm libraries.
Call Stack (most recent call first):
  /usr/src/llvm/cmake/modules/LLVM-Config.cmake:54 (explicit_map_components_to_libraries)
  /usr/src/llvm/cmake/modules/LLVM-Config.cmake:47 (explicit_llvm_config)
  /usr/src/llvm/cmake/modules/AddLLVM.cmake:86 (llvm_config)
  /usr/src/llvm/cmake/modules/AddLLVM.cmake:112 (add_llvm_executable)
  CMakeLists.txt:17 (add_llvm_example)