QtCreator中CMake调用pkg-config失败编译报错求助

Hey there, let's get this sorted out! The issue you're facing is because CMake doesn't interpret shell-style backticks the way a terminal does—when you put pkg-config --cflags --libs gtk+-3.0 directly into CMAKE_CXX_FLAGS, it's passing those exact strings as compiler arguments instead of running the pkg-config command to get the actual flags. Here's how to fix it properly:

The Right Way: Use CMake's PkgConfig Module #

CMake has a built-in module to handle pkg-config seamlessly, which is the recommended approach for cross-platform compatibility. Replace your existing CMAKE_CXX_FLAGS line with these steps in your CMakeLists.txt:

1. Find the pkg-config tool (make sure it's installed on your system first):

   find_package(PkgConfig REQUIRED)
   

2. Locate GTK+3 libraries and headers using pkg-config:

   pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
   

3. Add GTK+3's include directories to your project:

   include_directories(${GTK3_INCLUDE_DIRS})
   

4. Add GTK+3's library directories:

   link_directories(${GTK3_LIBRARY_DIRS})
   

5. Apply additional compiler flags from GTK+3:

   add_definitions(${GTK3_CFLAGS_OTHER})
   

6. Link your target against GTK+3 libraries:

   # Replace "your_project_name" with the actual name of your executable/target
   target_link_libraries(your_project_name ${GTK3_LIBRARIES})
   

Why This Works #

The pkg_check_modules command runs pkg-config behind the scenes, parses its output, and stores the necessary flags in variables like ${GTK3_INCLUDE_DIRS} and ${GTK3_LIBRARIES}. CMake then uses these variables correctly to configure your compiler and linker settings.

Pre-Requisites to Double-Check #

Make sure you have the required packages installed on your system:

• On Debian/Ubuntu-based systems:

  sudo apt-get install pkg-config libgtk-3-dev
  

• On Fedora/RHEL:

  sudo dnf install pkg-config gtk3-devel
  

Alternative: Manual pkg-config Execution (Not Recommended) #

If you really want to run pkg-config manually (though the module approach is better), you can use CMake's execute_process to capture the output:

execute_process(
    COMMAND pkg-config --cflags gtk+-3.0
    OUTPUT_VARIABLE GTK_CFLAGS
    OUTPUT_STRIP_TRAILING_WHITESPACE
)
execute_process(
    COMMAND pkg-config --libs gtk+-3.0
    OUTPUT_VARIABLE GTK_LIBS
    OUTPUT_STRIP_TRAILING_WHITESPACE
)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 ${GTK_CFLAGS}")
target_link_libraries(your_project_name ${GTK_LIBS})

After updating your CMakeLists.txt, go back to Qt Creator, re-run CMake configuration (via "Projects" tab > "Build" > "Run CMake"), and try compiling again—it should work now!

内容的提问来源于stack exchange，提问作者user9074174