将LLVM添加到我的Cmake项目中:为什么LLVM的Cmake文件中存在硬编码路径？

我在我的C++项目中使用LLVM/Clang.我可以使用Makefile构建并运行一切.

我现在正试图转移到Cmake,我无法让事情发挥作用.让我解释一下我做了什么.

我正在学习本教程:

http://llvm.org/docs/CMake.html#embedding

该网页的相关摘要如下:

从LLVM 3.5开始,CMake和autoconf/Makefile构建系统都将LLVM库导出为可导入的CMake目标.

大!我将下载LLVM 3.5,我应该好好去.我去了下载页面:

http://llvm.org/releases/download.html

并为Ubuntu 14.04 Linux下载了Clang的预构建二进制文件.

然后,我将以下内容添加到我的CMakeLists.txt文件中:

find_path (LLVM_DIR LLVM-Config.cmake
     /home/dev/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu/share/llvm/cmake
         )
message(STATUS "LLVM_DIR = ${LLVM_DIR}")
find_package(LLVM REQUIRED CONFIG)

(这与教程相同,除了我设置,LLVM_DIR因为它当前位于非标准位置.)

当我运行时cmake,我收到以下错误:

[dev@beauty:/path/to/project/build (develop)] $ cmake ..
-- LLVM_DIR = /home/dev/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu/share/llvm/cmake
CMake Error at /home/dev/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu/share/llvm/cmake/LLVMConfig.cmake:50 (include):
  include could not find load file:

    /home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install/share/llvm/cmake/LLVMExports.cmake
Call Stack (most recent call first):
  CMakeLists.txt:14 (find_package)


CMake Error at /home/dev/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu/share/llvm/cmake/LLVMConfig.cmake:53 (include):
  include could not find load file:

    /home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install/share/llvm/cmake/LLVM-Config.cmake
Call Stack (most recent call first):
  CMakeLists.txt:14 (find_package)

所以Cmake似乎正在寻找LLVM的Cmake文件,但是Cmake正在抱怨一些开头的路径/home/ben/.

实际上,似乎LLVM的LLVMConfig.cmake文件中有一些与我的机器无关的绝对路径.例如:

[dev@beauty:~/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu ] $ head ./share/llvm/cmake/LLVMConfig.cmake
# This file provides information and services to the final user.

set(LLVM_INSTALL_PREFIX "/home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install")

set(LLVM_VERSION_MAJOR 3)
set(LLVM_VERSION_MINOR 5)
set(LLVM_VERSION_PATCH 0)
set(LLVM_PACKAGE_VERSION 3.5.0)

set(LLVM_COMMON_DEPENDS )

他ben和你在这个档案里做了什么？他出现在几个地方:

[dev@beauty:~/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu ] $ grep ben ./share/llvm/cmake/LLVMConfig.cmake
set(LLVM_INSTALL_PREFIX "/home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install")
set(LLVM_INCLUDE_DIRS "/home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install/include")
set(LLVM_LIBRARY_DIRS "/home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install/lib")
set(LLVM_CMAKE_DIR "/home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install/share/llvm/cmake")
set(LLVM_TOOLS_BINARY_DIR "/home/ben/development/llvm/3.5/final/Phase3/Release/llvmCore-3.5.0-final.install/bin")

不用说,我的机器上不存在这些路径.我很困惑为什么这些文件中包含这些路径？我应该运行一个工具或什么来改变我的机器的这些路径？或者我需要手动更改它们吗？

编辑:出于好奇,我手动更改了所有这些路径以指向我的机器上的路径:

[dev@beauty:~/Downloads/clang+llvm-3.5.0-x86_64-linux-gnu/share/llvm/cmake ] $ sed -i -e's/.home.ben.development.llvm.3.5.final.Phase3.Release.llvmCore-3.5.0-final.install/\/home\/dev\/Downloads\/clang+llvm-3.5.0-x86_64-linux-gnu/g' *

在那之后,Cmake不再抱怨,我的构建继续进行.

我还是想知道为什么我需要那样做.