Question

我的简单项目包含2个“库”a和b以及可执行文件c。我将库a（PUBLIC）的包含路径设置为X（出于测试目的，实际上没有这样的路径）。
现在，b私下与a和c链接b。我希望在编译c.cpp时X不在包含路径中，因为“它不应该知道a，因为它在b中是私有的”但显然它就在这里。

所以我的问题是它的意图行为与否以及原因。

我的代码：

a.cpp

void a() {}

b.cpp

void b() {}

c.cpp

int main() {}

的CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

add_library(a a.cpp)
target_include_directories(a PUBLIC X)

add_library(b b.cpp)
target_link_libraries(b PRIVATE a)

add_executable(c c.cpp)
target_link_libraries(c PUBLIC b)

（详细）编译日志：

 /usr/local/Cellar/cmake/3.8.1/bin/cmake -H/Users/alexeyd/test/dir -B/Users/alexeyd/test/dir/build --check-build-system CMakeFiles/Makefile.cmake 0
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/Makefile2 c
/usr/local/Cellar/cmake/3.8.1/bin/cmake -H/Users/alexeyd/test/dir -B/Users/alexeyd/test/dir/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_progress_start /Users/alexeyd/test/dir/build/CMakeFiles 6
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/Makefile2 CMakeFiles/c.dir/all
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/a.dir/build.make CMakeFiles/a.dir/depend
cd /Users/alexeyd/test/dir/build && /usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_depends "Unix Makefiles" /Users/alexeyd/test/dir /Users/alexeyd/test/dir /Users/alexeyd/test/dir/build /Users/alexeyd/test/dir/build /Users/alexeyd/test/dir/build/CMakeFiles/a.dir/DependInfo.cmake --color=
Dependee "/Users/alexeyd/test/dir/build/CMakeFiles/a.dir/DependInfo.cmake" is newer than depender "/Users/alexeyd/test/dir/build/CMakeFiles/a.dir/depend.internal".
Dependee "/Users/alexeyd/test/dir/build/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/Users/alexeyd/test/dir/build/CMakeFiles/a.dir/depend.internal".
Scanning dependencies of target a
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/a.dir/build.make CMakeFiles/a.dir/build
[ 16%] Building CXX object CMakeFiles/a.dir/a.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++   -I/Users/alexeyd/test/dir/X   -o CMakeFiles/a.dir/a.cpp.o -c /Users/alexeyd/test/dir/a.cpp
[ 33%] Linking CXX static library liba.a
/usr/local/Cellar/cmake/3.8.1/bin/cmake -P CMakeFiles/a.dir/cmake_clean_target.cmake
/usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_link_script CMakeFiles/a.dir/link.txt --verbose=1
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar qc liba.a  CMakeFiles/a.dir/a.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib liba.a
[ 33%] Built target a
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/b.dir/build.make CMakeFiles/b.dir/depend
cd /Users/alexeyd/test/dir/build && /usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_depends "Unix Makefiles" /Users/alexeyd/test/dir /Users/alexeyd/test/dir /Users/alexeyd/test/dir/build /Users/alexeyd/test/dir/build /Users/alexeyd/test/dir/build/CMakeFiles/b.dir/DependInfo.cmake --color=
Dependee "/Users/alexeyd/test/dir/build/CMakeFiles/b.dir/DependInfo.cmake" is newer than depender "/Users/alexeyd/test/dir/build/CMakeFiles/b.dir/depend.internal".
Dependee "/Users/alexeyd/test/dir/build/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/Users/alexeyd/test/dir/build/CMakeFiles/b.dir/depend.internal".
Scanning dependencies of target b
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/b.dir/build.make CMakeFiles/b.dir/build
[ 50%] Building CXX object CMakeFiles/b.dir/b.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++   -I/Users/alexeyd/test/dir/X   -o CMakeFiles/b.dir/b.cpp.o -c /Users/alexeyd/test/dir/b.cpp
[ 66%] Linking CXX static library libb.a
/usr/local/Cellar/cmake/3.8.1/bin/cmake -P CMakeFiles/b.dir/cmake_clean_target.cmake
/usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_link_script CMakeFiles/b.dir/link.txt --verbose=1
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar qc libb.a  CMakeFiles/b.dir/b.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib libb.a
[ 66%] Built target b
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/c.dir/build.make CMakeFiles/c.dir/depend
cd /Users/alexeyd/test/dir/build && /usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_depends "Unix Makefiles" /Users/alexeyd/test/dir /Users/alexeyd/test/dir /Users/alexeyd/test/dir/build /Users/alexeyd/test/dir/build /Users/alexeyd/test/dir/build/CMakeFiles/c.dir/DependInfo.cmake --color=
Dependee "/Users/alexeyd/test/dir/build/CMakeFiles/c.dir/DependInfo.cmake" is newer than depender "/Users/alexeyd/test/dir/build/CMakeFiles/c.dir/depend.internal".
Dependee "/Users/alexeyd/test/dir/build/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/Users/alexeyd/test/dir/build/CMakeFiles/c.dir/depend.internal".
Scanning dependencies of target c
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f CMakeFiles/c.dir/build.make CMakeFiles/c.dir/build
[ 83%] Building CXX object CMakeFiles/c.dir/c.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++   -I/Users/alexeyd/test/dir/X   -o CMakeFiles/c.dir/c.cpp.o -c /Users/alexeyd/test/dir/c.cpp
[100%] Linking CXX executable c
/usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_link_script CMakeFiles/c.dir/link.txt --verbose=1
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++   -Wl,-search_paths_first -Wl,-headerpad_max_install_names  CMakeFiles/c.dir/c.cpp.o  -o c libb.a liba.a
[100%] Built target c
/usr/local/Cellar/cmake/3.8.1/bin/cmake -E cmake_progress_start /Users/alexeyd/test/dir/build/CMakeFiles 0

日志的有趣部分：

[ 83%] Building CXX object CMakeFiles/c.dir/c.cpp.o 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++   -I/Users/alexeyd/test/dir/X   -o CMakeFiles/c.dir/c.cpp.o -c /Users/alexeyd/test/dir/c.cpp

我使用CMake 3.8.1

Answer 1

如果指定最小CMake版本＆gt; = 2.8.12：

，则不会出现奇怪的行为

cmake_minimum_required(VERSION 2.8.12)

在CMake 2.8.12之前，

target_include_directories和PRIVATE / PUBLIC区别不存在。我的看法是，对于早于CMake的版本，CMake选择默认创建所有内容PUBLIC。

为什么包含路径即使对于私有链接也是继承的

1 个答案: