为何链接库的包含目录未正确传递？CMake配置问题排查

静态库依赖链为 myTest -> myFoo -> myBar，在myTest的头文件test_file.h中写入#include "myBar/my_bar_class.h"时，编译报错找不到该文件。打印myTest的INTERFACE_INCLUDE_DIRECTORIES属性，仅显示自身和myFoo的包含目录，未包含myBar的路径。以下是各库的CMake配置：

myTest库的CMakeLists.txt #

cmake_minimum_required(VERSION 3.23)

add_library(myTest STATIC)

target_sources(myTest 
    INTERFACE
        FILE_SET HEADERS
        BASE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
        FILES
        ${CMAKE_CURRENT_SOURCE_DIR}/include/myTest/test_file.h
)

target_link_libraries(
  PUBLIC
    myFoo
)

...

myFoo库的CMakeLists.txt #

cmake_minimum_required(VERSION 3.23)

add_library(myFoo STATIC)

target_sources(myFoo
    INTERFACE
        FILE_SET HEADERS
        BASE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
        FILES
        ${CMAKE_CURRENT_SOURCE_DIR}/include/myFoo/a.h
)

target_link_libraries(
  PUBLIC
    myBar
)

target_include_directories(myFoo INTERFACE
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/myFoo>
  $<INSTALL_INTERFACE:include/myFoo>
)

...

myBar库的CMakeLists.txt #

cmake_minimum_required(VERSION 3.23)

add_library(myBar STATIC)

target_sources(myBar
    INTERFACE
        FILE_SET HEADERS
        BASE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
        FILES
        ${CMAKE_CURRENT_SOURCE_DIR}/include/myBar/my_bar_class.h
)

target_include_directories(myFoo INTERFACE
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/myBar>
  $<INSTALL_INTERFACE:include/myBar>
)

...

• 核心错误：myBar的CMakeLists.txt中，target_include_directories的目标写错了——本该设置myBar的包含目录，却误写为myFoo。这导致myBar自身没有配置INTERFACE包含目录，依赖链无法将myBar的头文件路径传递给上层的myTest。
• 具体修正步骤：
  1. 修正myBar的target_include_directories目标，并调整路径根目录：

     target_include_directories(myBar INTERFACE
       $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
       $<INSTALL_INTERFACE:include>
     )
     

     这里将根目录设为include而非include/myBar，是因为你的头文件包含语句是#include "myBar/my_bar_class.h"，需要让编译器找到include作为根路径，才能正确解析子目录下的头文件。
  2. 同步调整myFoo的target_include_directories逻辑，保持一致性：

     target_include_directories(myFoo INTERFACE
       $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
       $<INSTALL_INTERFACE:include>
     )
     

• 逻辑说明：CMake的PUBLIC/INTERFACE依赖传递是基于目标自身属性的，只有myBar正确配置了自己的INTERFACE包含目录，myFoo通过PUBLIC链接myBar时，才能把myBar的INTERFACE属性传递给myTest，最终让myTest找到myBar的头文件。

内容的提问来源于stack exchange，提问作者Sean M.