如何获取cmake进程的工作目录？

Question

如何获取调用 cmake 的工作目录？

我知道我可以运行 execute_process() 在我的 CMake 代码的开头，但也许有一些更好的方法，比如 CMake 进程的工作目录的内置变量。

我想要实现的是将CMake变量中给定的相对路径（用-D...给出）转换为CMake中的绝对路径。

Answer 1

What I want to achieve is to convert a relative path given in a CMake variable (given with -D...) to an absolute path in CMake.

然后只需在 CMakeLists.txt 中创建 PATH 类型（用于目录）或 FILEPATH 类型的缓存变量。 CMake 会自动将未类型化的命令行参数转换为绝对路径。

$ cat CMakeLists.txt
cmake_minimum_required(VERSION 3.22)
project(test NONE)

set(input_file "" CACHE FILEPATH "some input file")
message(STATUS "${input_file}")

$ cmake -S . -B build -Dinput_file=foo.txt
-- /path/to/foo.txt
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build

查看文档：

It is possible for the cache entry to exist prior to the call but have no type set if it was created on the cmake(1) command line by a user through the -D<var>=<value> option without specifying a type. In this case the set command will add the type. Furthermore, if the <type> is PATH or FILEPATH and the <value> provided on the command line is a relative path, then the set command will treat the path as relative to the current working directory and convert it to an absolute path.

此处：https://cmake.org/cmake/help/latest/command/set.html?highlight=current%20working%20directory

相关地，当运行处于脚本模式（而不是项目模式）时，设置了几个常用变量到当前工作目录：

When run in -P script mode, CMake sets the variables CMAKE_BINARY_DIR, CMAKE_SOURCE_DIR, CMAKE_CURRENT_BINARY_DIR and CMAKE_CURRENT_SOURCE_DIR to the current working directory.

https://cmake.org/cmake/help/latest/variable/CMAKE_SOURCE_DIR.html

如何获取cmake进程的工作目录？

How to get the working directory of the cmake process?

cmake