CMake无法找到G2O包及头文件的编译问题排查

项目结构 #

scan_inconsistency
|-- CMakeLists.txt
|-- build
|-- cmake_modules
|-- libs
|   |-- CMakeLists.txt
|   |-- consist
|   `-- g2o
`-- src
    |-- CMakeLists.txt
    `-- main.cpp

背景与问题 #

consist包已完成Qt5适配、Eigen路径调整等修改，g2o是consist的依赖，cmake_modules目录复制自consist/cmake并修改。编译时遇到两个问题：

1. 单独编译consist时，make阶段提示找不到g2o/core/sparse_optimizer.h
2. 编译顶层CMakeLists.txt时，make阶段提示找不到g2o/core/optimizable_graph.h

CMakeLists调整方案 #

1. 顶层CMakeLists.txt修改 #

确保自定义cmake模块路径被识别，提前查找g2o并全局传递依赖信息：

cmake_minimum_required(VERSION 3.10)
project(scan_inconsistency)

# 将自定义cmake_modules加入模块搜索路径
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${PROJECT_SOURCE_DIR}/cmake_modules)

# 查找g2o依赖，全局设置头文件和库路径
find_package(G2O REQUIRED)
include_directories(${G2O_INCLUDE_DIR})
link_directories(${G2O_LIBRARY_DIR})

# 编译子项目
add_subdirectory(libs)
add_subdirectory(src)

2. libs/CMakeLists.txt修改 #

调整编译顺序，保证g2o先编译完成，同时给consist明确传递g2o依赖：

# 优先编译g2o子项目
add_subdirectory(g2o)

# 编译consist
add_subdirectory(consist)

# 给consist添加g2o头文件路径
target_include_directories(consist PUBLIC ${G2O_INCLUDE_DIR})
# 将g2o库链接到consist
target_link_libraries(consist PUBLIC ${G2O_LIBRARIES})

3. src/CMakeLists.txt修改 #

确保主程序能继承consist的g2o依赖，必要时显式添加头文件路径：

add_executable(scan_inconsistency main.cpp)

# 链接consist库，自动继承其g2o依赖
target_link_libraries(scan_inconsistency PRIVATE consist)

# 若仍存在头文件找不到问题，显式添加g2o头文件路径
target_include_directories(scan_inconsistency PRIVATE ${G2O_INCLUDE_DIR})

4. 单独编译consist的补充配置 #

如果需要单独编译consist，需在consist/CMakeLists.txt中添加g2o的查找逻辑：

# 加入g2o查找
find_package(G2O REQUIRED)
include_directories(${G2O_INCLUDE_DIR})

额外检查点 #

• 确认cmake_modules/FindG2O.cmake配置正确，能正确识别g2o的include和lib目录
• 确保g2o已正确编译，其头文件和库文件路径与CMake查找结果一致

内容的提问来源于stack exchange，提问作者Shrinivas Iyengar