c++ - 交叉编译SFML时对libpng相关符号的 undefined reference

Question

我正在研究从 Linux 到 Windows 的 SFML 交叉编译。我已经安装了所有依赖项。当我尝试构建 SFML 库时，它在开始时一切顺利，构建系统、网络和窗口。然而，在开始构建 sfml-graphics 时，它没有问题，但无法链接库。

[ 16%] Built target sfml-system
[ 18%] Built target sfml-main
[ 39%] Built target sfml-window
[ 50%] Built target sfml-network
[ 51%] Linking CXX shared library ../../../lib/sfml-graphics-2.dll
/usr/lib/gcc/i686-w64-mingw32/6.2-posix/../../../../i686-w64-mingw32/lib/../lib/libfreetype.a(sfnt.o): In function `Load_SBit_Png':
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:209: undefined reference to `png_create_read_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:219: undefined reference to `png_create_info_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:227: undefined reference to `png_set_longjmp_fn'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:326: undefined reference to `png_destroy_read_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:233: undefined reference to `png_set_read_fn'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:235: undefined reference to `png_read_info'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:236: undefined reference to `png_get_IHDR'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:254: undefined reference to `png_set_expand_gray_1_2_4_to_8'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:261: undefined reference to `png_get_valid'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:276: undefined reference to `png_set_interlace_handling'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:278: undefined reference to `png_set_filler'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:281: undefined reference to `png_read_update_info'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:282: undefined reference to `png_get_IHDR'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:301: undefined reference to `png_set_read_user_transform_fn'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:223: undefined reference to `png_destroy_read_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:248: undefined reference to `png_set_palette_to_rgb'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:273: undefined reference to `png_set_gray_to_rgb'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:268: undefined reference to `png_set_packing'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:265: undefined reference to `png_set_strip_16'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:262: undefined reference to `png_set_tRNS_to_alpha'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:319: undefined reference to `png_read_image'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:323: undefined reference to `png_read_end'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:306: undefined reference to `png_set_read_user_transform_fn'
/usr/lib/gcc/i686-w64-mingw32/6.2-posix/../../../../i686-w64-mingw32/lib/../lib/libfreetype.a(sfnt.o): In function `error_callback':
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:125: undefined reference to `png_get_error_ptr'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:132: undefined reference to `png_set_longjmp_fn'
/usr/lib/gcc/i686-w64-mingw32/6.2-posix/../../../../i686-w64-mingw32/lib/../lib/libfreetype.a(sfnt.o): In function `read_data_from_FT_Stream':
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:156: undefined reference to `png_get_io_ptr'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:162: undefined reference to `png_get_error_ptr'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:166: undefined reference to `png_error'
collect2: error: ld returned 1 exit status
src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/build.make:884: recipe for target 'lib/sfml-graphics-2.dll' failed
make[2]: *** [lib/sfml-graphics-2.dll] Error 1
CMakeFiles/Makefile2:339: recipe for target 'src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/all' failed
make[1]: *** [src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

我试过在 make 之前指定 LDFLAGS，但没有用。

cmake -DCMAKE_TOOLCHAIN_FILE=/etc/toolchains/win32-tc.cmake -DCMAKE_INSTALL_PREFIX=/usr/i686-w64-mingw32 .. && LDFLAGS="-L/usr/i686-w64-mingw32/lib -lpng" sudo make all install

我已经成功构建了 libpng，并且列出 /usr/i686-w64-mingw32/lib(我的交叉编译器 lib 目录)显示静态库在那里。

$ ls /usr/i686-w64-mingw32/lib | grep libpng
libpng
libpng16.a
libpng16.dll.a
libpng.a
libpng.dll.a

我不知道哪里出了问题。有人有任何线索吗？提前致谢。

编辑:提供更有趣的输出以尝试查明问题。

$ cmake -DCMAKE_TOOLCHAIN_FILE=/etc/toolchains/win32-tc.cmake -DCMAKE_INSTALL_PREFIX=/usr/i686-w64-mingw32 -DCMAKE_RULE_MESSAGES:BOOL=OFF -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .. && sudo make --no-print-directory all install
-- Configuring done
-- Generating done
-- Build files have been written to: /home/chemicalchems/Downloads/SFML/build
/usr/bin/cmake -H/home/chemicalchems/Downloads/SFML -B/home/chemicalchems/Downloads/SFML/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/chemicalchems/Downloads/SFML/build/CMakeFiles /home/chemicalchems/Downloads/SFML/build/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make -f src/SFML/System/CMakeFiles/sfml-system.dir/build.make src/SFML/System/CMakeFiles/sfml-system.dir/depend
cd /home/chemicalchems/Downloads/SFML/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/chemicalchems/Downloads/SFML /home/chemicalchems/Downloads/SFML/src/SFML/System /home/chemicalchems/Downloads/SFML/build /home/chemicalchems/Downloads/SFML/build/src/SFML/System /home/chemicalchems/Downloads/SFML/build/src/SFML/System/CMakeFiles/sfml-system.dir/DependInfo.cmake --color=
make -f src/SFML/System/CMakeFiles/sfml-system.dir/build.make src/SFML/System/CMakeFiles/sfml-system.dir/build
make[2]: Nothing to be done for 'src/SFML/System/CMakeFiles/sfml-system.dir/build'.
[ 16%] Built target sfml-system
make -f src/SFML/Main/CMakeFiles/sfml-main.dir/build.make src/SFML/Main/CMakeFiles/sfml-main.dir/depend
cd /home/chemicalchems/Downloads/SFML/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/chemicalchems/Downloads/SFML /home/chemicalchems/Downloads/SFML/src/SFML/Main /home/chemicalchems/Downloads/SFML/build /home/chemicalchems/Downloads/SFML/build/src/SFML/Main /home/chemicalchems/Downloads/SFML/build/src/SFML/Main/CMakeFiles/sfml-main.dir/DependInfo.cmake --color=
make -f src/SFML/Main/CMakeFiles/sfml-main.dir/build.make src/SFML/Main/CMakeFiles/sfml-main.dir/build
make[2]: Nothing to be done for 'src/SFML/Main/CMakeFiles/sfml-main.dir/build'.
[ 18%] Built target sfml-main
make -f src/SFML/Window/CMakeFiles/sfml-window.dir/build.make src/SFML/Window/CMakeFiles/sfml-window.dir/depend
cd /home/chemicalchems/Downloads/SFML/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/chemicalchems/Downloads/SFML /home/chemicalchems/Downloads/SFML/src/SFML/Window /home/chemicalchems/Downloads/SFML/build /home/chemicalchems/Downloads/SFML/build/src/SFML/Window /home/chemicalchems/Downloads/SFML/build/src/SFML/Window/CMakeFiles/sfml-window.dir/DependInfo.cmake --color=
make -f src/SFML/Window/CMakeFiles/sfml-window.dir/build.make src/SFML/Window/CMakeFiles/sfml-window.dir/build
make[2]: Nothing to be done for 'src/SFML/Window/CMakeFiles/sfml-window.dir/build'.
[ 39%] Built target sfml-window
make -f src/SFML/Network/CMakeFiles/sfml-network.dir/build.make src/SFML/Network/CMakeFiles/sfml-network.dir/depend
cd /home/chemicalchems/Downloads/SFML/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/chemicalchems/Downloads/SFML /home/chemicalchems/Downloads/SFML/src/SFML/Network /home/chemicalchems/Downloads/SFML/build /home/chemicalchems/Downloads/SFML/build/src/SFML/Network /home/chemicalchems/Downloads/SFML/build/src/SFML/Network/CMakeFiles/sfml-network.dir/DependInfo.cmake --color=
make -f src/SFML/Network/CMakeFiles/sfml-network.dir/build.make src/SFML/Network/CMakeFiles/sfml-network.dir/build
make[2]: Nothing to be done for 'src/SFML/Network/CMakeFiles/sfml-network.dir/build'.
[ 50%] Built target sfml-network
make -f src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/build.make src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/depend
cd /home/chemicalchems/Downloads/SFML/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/chemicalchems/Downloads/SFML /home/chemicalchems/Downloads/SFML/src/SFML/Graphics /home/chemicalchems/Downloads/SFML/build /home/chemicalchems/Downloads/SFML/build/src/SFML/Graphics /home/chemicalchems/Downloads/SFML/build/src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/DependInfo.cmake --color=
make -f src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/build.make src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/build
cd /home/chemicalchems/Downloads/SFML/build/src/SFML/Graphics && /usr/bin/cmake -E cmake_link_script CMakeFiles/sfml-graphics.dir/link.txt --verbose=1
/usr/bin/cmake -E remove -f CMakeFiles/sfml-graphics.dir/objects.a
/usr/bin/ar cr CMakeFiles/sfml-graphics.dir/objects.a @CMakeFiles/sfml-graphics.dir/objects1.rsp
/usr/bin/i686-w64-mingw32-g++-posix   -O3 -DNDEBUG  -shared -o ../../../lib/sfml-graphics-2.dll -Wl,--out-implib,../../../lib/libsfml-graphics.a -Wl,--major-image-version,2,--minor-image-version,4 -Wl,--whole-archive CMakeFiles/sfml-graphics.dir/objects.a -Wl,--no-whole-archive @CMakeFiles/sfml-graphics.dir/linklibs.rsp
/usr/lib/gcc/i686-w64-mingw32/6.2-posix/../../../../i686-w64-mingw32/lib/../lib/libfreetype.a(sfnt.o): In function `Load_SBit_Png':
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:209: undefined reference to `png_create_read_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:219: undefined reference to `png_create_info_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:227: undefined reference to `png_set_longjmp_fn'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:326: undefined reference to `png_destroy_read_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:233: undefined reference to `png_set_read_fn'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:235: undefined reference to `png_read_info'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:236: undefined reference to `png_get_IHDR'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:254: undefined reference to `png_set_expand_gray_1_2_4_to_8'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:261: undefined reference to `png_get_valid'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:276: undefined reference to `png_set_interlace_handling'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:278: undefined reference to `png_set_filler'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:281: undefined reference to `png_read_update_info'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:282: undefined reference to `png_get_IHDR'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:301: undefined reference to `png_set_read_user_transform_fn'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:223: undefined reference to `png_destroy_read_struct'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:248: undefined reference to `png_set_palette_to_rgb'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:273: undefined reference to `png_set_gray_to_rgb'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:268: undefined reference to `png_set_packing'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:265: undefined reference to `png_set_strip_16'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:262: undefined reference to `png_set_tRNS_to_alpha'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:319: undefined reference to `png_read_image'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:323: undefined reference to `png_read_end'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:306: undefined reference to `png_set_read_user_transform_fn'
/usr/lib/gcc/i686-w64-mingw32/6.2-posix/../../../../i686-w64-mingw32/lib/../lib/libfreetype.a(sfnt.o): In function `error_callback':
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:125: undefined reference to `png_get_error_ptr'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:132: undefined reference to `png_set_longjmp_fn'
/usr/lib/gcc/i686-w64-mingw32/6.2-posix/../../../../i686-w64-mingw32/lib/../lib/libfreetype.a(sfnt.o): In function `read_data_from_FT_Stream':
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:156: undefined reference to `png_get_io_ptr'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:162: undefined reference to `png_get_error_ptr'
/home/chemicalchems/Downloads/libfreetype/src/sfnt/pngshim.c:166: undefined reference to `png_error'
collect2: error: ld returned 1 exit status
src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/build.make:854: recipe for target 'lib/sfml-graphics-2.dll' failed
make[2]: *** [lib/sfml-graphics-2.dll] Error 1
CMakeFiles/Makefile2:342: recipe for target 'src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/all' failed
make[1]: *** [src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/all] Error 2
Makefile:130: recipe for target 'all' failed
make: *** [all] Error 2

编辑 2: 请求工具链文件

SET(CMAKE_SYSTEM_NAME Windows)

SET(COMPILER_PREFIX i686-w64-mingw32)

SET(CMAKE_C_COMPILER ${COMPILER_PREFIX}-gcc-posix)
SET(CMAKE_CXX_COMPILER ${COMPILER_PREFIX}-g++-posix)
SET(CMAKE_RC_COMPILER ${COMPILER_PREFIX}-windres)

SET(CMAKE_FIND_ROOT_PATH /usr/${COMPILER_PREFIX})

set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

set(CMAKE_INSTALL_PREFIX:PATH /usr/${COMPILER_PREFIX})

Answer 1

如果您需要做的只是通过交叉编译为 Windows 构建 SFML - 另一种方法是使用 MXE交叉编译环境。这样你只需要:

1. 下载MXE package或克隆 Git repo
2. cd 进入目录
3. 根据需要编辑/创建 settings.mk 配置文件
4. 执行制作sfml

然后 MXE 会自动下载并构建 SFML 所需的所有依赖项。

MXE 教程:http://mxe.cc/#tutorial

示例 settings.mk 文件:

# This variable controls the number of compilation processes
# within one package ("intra-package parallelism").
JOBS := 12

# This variable controls the targets that will build.
#MXE_TARGETS :=  i686-w64-mingw32.static i686-w64-mingw32.shared  x86_64-w64-mingw32.static x86_64-w64-mingw32.shared
MXE_TARGETS :=  x86_64-w64-mingw32.static

这并不能真正帮助您解决构建错误，但我将其发布在这里以防万一您无法解决它并且您想尝试其他解决方案，以及其他尝试交叉编译 SFML 的人.