Cmake 安装目标触发

Question

我正在使用 cmake 编写构建配置:除了带有自己代码的主项目之外，还有一些外部库。为了轻松更新这些库(zlib、libpng、...)，我不想修改其 cmakelists 文件，但我需要特定的库目标(例如在 target_link_libraries() 中使用)。
另一个限制是我不能只说我的代码需要安装外部库，所有东西都必须位于一个源代码树中并且必须一起构建。
为了保持库提供的所有结构化(库、头文件)，我想将库安装(如 make install 那样)到本地构建文件夹，然后包含生成的 cmake 文件以将所需的目标导入到我的项目中。

我想流程如下:

使用 add_subdirectory() 构建外部库

将外部库文件安装到本地目录

使用生成的 cmake 文件导入目标

在主项目 cmake 文件中使用导入的目标

问题是自动执行第 2 步(需要在主项目 CMakeLists.txt 中触发 install 目标之后 add_subdiretory)。我可以构建和安装所有库，然后构建自己的代码，但这并不方便。

所以问题是如何告诉 cmake 在构建期间进行中间安装？

这里有一个小工作示例:

文件结构:

prj/CMakeLists.txt
prj/src/main.cpp
lib/CMakeLists.txt
lib/include/libheader.h
lib/src/libsource.cpp

prj/CMakeLists.txt

project(TestProject)
cmake_minimum_required(VERSION 2.8)
set(CMAKE_VERBOSE_MAKEFILE on)
set(WORK_DIR ${CMAKE_CURRENT_SOURCE_DIR})
# supposed to use add_subdirectory here (with forced install).
# and then include prespecified include-file as here.
include_directories(${WORK_DIR}/../lib/build/install/include)
include(${WORK_DIR}/../lib/build/install/lib/libtargets.cmake)
add_executable(main ${WORK_DIR}/src/main.cpp)
target_link_libraries(main library_target)

库/CMakeLists.txt

project(TestLib)
cmake_minimum_required(VERSION 2.8)
set(CMAKE_VERBOSE_MAKEFILE on)
set(WORK_DIR ${CMAKE_CURRENT_SOURCE_DIR})
include_directories(${WORK_DIR}/include)
add_library(library_target STATIC ${WORK_DIR}/src/libsource.cpp)
set(CMAKE_INSTALL_PREFIX ${CMAKE_CURRENT_BINARY_DIR}/install)
install(FILES ${WORK_DIR}/include/libheader.h DESTINATION include)
install(TARGETS library_target DESTINATION lib EXPORT libtargets)
install(EXPORT libtargets DESTINATION lib)

prj/src/main.cpp

#include <iostream>
#include "libheader.h"

using std::cout;

int main()
{
    cout << getRandomNumber() << "\n";
    return 0;
}

lib/include/libheader.h

#ifndef _LIBHEADER_H_
#define _LIBHEADER_H_

int getRandomNumber();

#endif

lib/src/libsource.cpp

#include <iostream>
#include "libheader.h"

int getRandomNumber()
{
    return 4; // guaranteed to be random.
}

您可以使用以下命令来构建所有:

pushd . && mkdir lib/build && cd lib/build && cmake .. && make && make install && popd && pushd . && mkdir prj/build && cd prj/build && cmake .. && make || popd

编辑:主项目中所需的 cmakelists:

set(CMAKE_INSTALL_PREFIX ${CMAKE_CURRENT_BINARY_DIR}/install)
add_subdirectory(${WORK_DIR}/../lib ${CMAKE_CURRENT_BINARY_DIR}/lib.d)
# force install here, somehow
# because if not we will get "include could not find load file" here.
include(${CMAKE_CURRENT_BINARY_DIR}/install/lib/libtargets.cmake)
include_directories(${CMAKE_CURRENT_BINARY_DIR}/install/include)

Answer 1

抱歉，我无权发表评论

所以，我把引用链接放在这里

https://cmake.org/Bug/view.php?id=14311

this is also useful when including prebuilt library binaries in the project.

add_library(prebuilt STATIC IMPORTED) set_property(TARGET prebuilt PROPERTY IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/libprebuilt.a)

install(TARGETS other_built_targets prebuilt EXPORT project-export RUNTIME DESTINATION bin LIBRARY DESTINATION lib ARCHIVE DESTINATION lib )

Making prebuilt an imported target makes in convenient to use in the project and treats it further like any other target.