Question

sdl2-image是作为静态库libSDL2_image.a构建和安装的，它依赖于另一个静态库，如webp，libpng等。当我链接它时：

add_executable(main main.cpp)
target_link_libraries(main
  SDL2::SDL2-static
  ${SDL2_IMAGE_LIBRARY}
)

失败，显示错误：

[ 50%] Linking CXX executable main
/usr/local/Cellar/cmake/3.11.1/bin/cmake -E cmake_link_script CMakeFiles/main.dir/link.txt --verbose=1
/Library/Developer/CommandLineTools/usr/bin/c++   -Wl,-search_paths_first -Wl,-headerpad_max_install_names  CMakeFiles/main.dir/main.cpp.o  -o main /Users/Ryan/vcpkg/installed/x64-osx/debug/lib/libSDL2d.a /Users/Ryan/vcpkg/installed/x64-osx/lib/libpng16.a /Users/Ryan/vcpkg/installed/x64-osx/debug/lib/libSDL2_image.a /Users/Ryan/vcpkg/installed/x64-osx/lib/libwebp.a /Users/Ryan/vcpkg/installed/x64-osx/lib/libjpeg.a /Users/Ryan/vcpkg/installed/x64-osx/lib/libpng16.a -lm -liconv -framework CoreVideo -framework Cocoa -framework IOKit -framework ForceFeedback -framework Carbon -framework CoreAudio -framework AudioToolbox -Wl,-undefined,error /Users/Ryan/vcpkg/installed/x64-osx/lib/libz.a
Undefined symbols for architecture x86_64:
  "_IMG_InitJPG", referenced from:
      _IMG_Init in libSDL2_image.a(IMG.c.o)
  "_IMG_InitPNG", referenced from:
      _IMG_Init in libSDL2_image.a(IMG.c.o)
  "_IMG_InitTIF", referenced from:
      _IMG_Init in libSDL2_image.a(IMG.c.o)
  "_IMG_Load", referenced from:

发生了什么事？

另一个问题：

提供一个静态库libA.a和libB.a，它依赖于libA.a. 如果我用libB.a链接程序，我还必须链接libA.a，例如

add_executable(main main.cpp)
target_link_libraries(main
  /path/to/libB.a
  /path/to/libA.a
)

有必要吗？如果和为什么？如果libA.a有其他依赖关系但我不知道，我该怎么办？

级联静态库链接机制

0 个答案: