c++ - CMake:如何使用 make 命令创建文件

Question

我需要创建以下始终过时的文件:${CMAKE_BINARY_DIR}/version.hpp.in
在 make 文件中执行任何目标之前。文件内容如下:

#define RELEASE_VERSION "${RELEASE}"
#define MAJOR_VERSION "${MAJOR}"
#define MINOR_VERSION "${MINOR}"
#define PATCH_VERSION "${PATCH}"
#define REVISION "${REVISION}"
#define SVNPATH "${SVNPATH}"

我的 CMake 文件中有以下代码，但它仅在运行 cmake 命令后执行:

FILE(WRITE ${CMAKE_BINARY_DIR}/version.hpp.in
"#define RELEASE_VERSION \"${RELEASE}\"\n"
"#define MAJOR_VERSION \"${MAJOR}\"\n"
"#define MINOR_VERSION \"${MINOR}\"\n"
"#define PATCH_VERSION \"${PATCH}\"\n"
"#define REVISION \"${REVISION}\"\n"
"#define SVNPATH \"${SVNPATH}\"\n"
)

我想在每次运行make 命令时生成version.hpp.in 文件。我该怎么做？

Answer 1

您可以为此使用 configure_file():

configure_file(version.hpp.in ${DESTPATH}/version.hpp)

其中 DESTPATH 是可选的，设置为您想要该文件的路径。

If the file is modified the build system will re-run CMake to re-configure the file and generate the build system again.

(来源:文档，见下文)

文件version.hpp:

#define RELEASE_VERSION "${RELEASE}"
#define MAJOR_VERSION "${MAJOR}"
#define MINOR_VERSION "${MINOR}"
#define PATCH_VERSION "${PATCH}"
#define REVISION "${REVISION}"
#define SVNPATH "${SVNPATH}" 

语法:

configure_file(<input> <output>
               [COPYONLY] [ESCAPE_QUOTES] [@ONLY]
               [NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF] ])

文档:

• CMake 3.0
• CMake 2.8.12

---

# 'example' is the targetname here, eg. using add_executable(example example.cpp)

add_custom_command(TARGET example PRE_BUILD COMMAND <CMAKE COMMAND HERE>)

---

最小示例

版本.h.in

#define VERSION ${VERSION}

只是为了测试......

CMakeLists.txt

cmake_minimum_required(VERSION 2.8.12)

set(VERSION 1.10)
set(TEMPLATE_DIR ${CMAKE_CURRENT_SOURCE_DIR})

add_executable(example example.cpp)

add_custom_command(TARGET example PRE_BUILD 
        COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_SOURCE_DIR}/SetVersion.cmake)

设置版本.cmake

configure_file(${CMAKE_CURRENT_SOURCE_DIR}/../Version.h.in ${CMAKE_CURRENT_SOURCE_DIR}/../Version.h)
message("Version set") # For testing only

现在像往常一样运行 cmake 和 make 并检查 HELLO 是否打印在 make 上。