makefile - SDL2 库在 Make 中找不到，但在 CMake 中找到

Question

我正在尝试在使用 Makefile 构建的项目中使用 SDL2、SDL2_ttf 和 SDL2_image。我尝试了很多不同的方法，但无论我到目前为止尝试了什么，SDL2_ttf 和 SDL2_image 都会抛出类似于以下内容的错误。

/Library/Frameworks/SDL2_ttf.framework/Headers/SDL_ttf.h:34:10: fatal error: 
      'SDL2/SDL.h' file not found

我可以使用以下 CMakeLists 和值成功地使用 CMake 构建项目。

cmake_minimum_required(VERSION 3.0)
project(kiss_sdl)


set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${kiss_sdl_SOURCE_DIR}/cmake")
set(BIN_DIR ${kiss_sdl_SOURCE_DIR}/bin)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)

add_definitions(-DRESDIR=\"../../\")

find_package(SDL2 REQUIRED)
include_directories(${SDL2_INCLUDE_DIR})

find_package(SDL2_ttf REQUIRED)
include_directories(${SDL2_TTF_INCLUDE_DIR})

find_package(SDL2_image REQUIRED)
include_directories(${SDL2_IMAGE_INCLUDE_DIR})


add_executable(kiss_sdl kiss_example1.c kiss_draw.c kiss_general.c kiss_posix.c kiss_widgets.c kiss_sdl.h)


target_link_libraries(kiss_sdl ${SDL2_LIBRARY} ${SDL2_TTF_LIBRARY} ${SDL2_IMAGE_LIBRARY})
install(TARGETS kiss_sdl RUNTIME DESTINATION ${BIN_DIR})

下面是我用来在 CMake 中查找 SDL 的 CMake 模块。

查找SDL2.cmake

# Locate SDL2 library
# This module defines
# SDL2_LIBRARY, the name of the library to link against
# SDL2_FOUND, if false, do not try to link to SDL2
# SDL2_INCLUDE_DIR, where to find SDL.h
#
# This module responds to the the flag:
# SDL2_BUILDING_LIBRARY
# If this is defined, then no SDL2_main will be linked in because
# only applications need main().
# Otherwise, it is assumed you are building an application and this
# module will attempt to locate and set the the proper link flags
# as part of the returned SDL2_LIBRARY variable.
#
# Don't forget to include SDL2main.h and SDL2main.m your project for the
# OS X framework based version. (Other versions link to -lSDL2main which
# this module will try to find on your behalf.) Also for OS X, this
# module will automatically add the -framework Cocoa on your behalf.
#
#
# Additional Note: If you see an empty SDL2_LIBRARY_TEMP in your configuration
# and no SDL2_LIBRARY, it means CMake did not find your SDL2 library
# (SDL2.dll, libsdl2.so, SDL2.framework, etc).
# Set SDL2_LIBRARY_TEMP to point to your SDL2 library, and configure again.
# Similarly, if you see an empty SDL2MAIN_LIBRARY, you should set this value
# as appropriate. These values are used to generate the final SDL2_LIBRARY
# variable, but when these values are unset, SDL2_LIBRARY does not get created.
#
#
# $SDL2 is an environment variable that would
# correspond to the ./configure --prefix=$SDL2
# used in building SDL2.
# l.e.galup 9-20-02
#
# Modified by Eric Wing.
# Added code to assist with automated building by using environmental variables
# and providing a more controlled/consistent search behavior.
# Added new modifications to recognize OS X frameworks and
# additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL2 guidelines.
# Added a search for SDL2main which is needed by some platforms.
# Added a search for threads which is needed by some platforms.
# Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# SDL2_LIBRARY to override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL2/SDL.h to just SDL.h
# This needed to change because "proper" SDL2 convention
# is #include "SDL.h", not <SDL2/SDL.h>. This is done for portability
# reasons because not all systems place things in SDL2/ (see FreeBSD).
#
# Ported by Johnny Patterson. This is a literal port for SDL2 of the FindSDL.cmake
# module with the minor edit of changing "SDL" to "SDL2" where necessary. This
# was not created for redistribution, and exists temporarily pending official
# SDL2 CMake modules.
#
# Note that on windows this will only search for the 32bit libraries, to search
# for 64bit change x86/i686-w64 to x64/x86_64-w64

#=============================================================================
# Copyright 2003-2009 Kitware, Inc.
#
# CMake - Cross Platform Makefile Generator
# Copyright 2000-2014 Kitware, Inc.
# Copyright 2000-2011 Insight Software Consortium
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# * Neither the names of Kitware, Inc., the Insight Software Consortium,
# nor the names of their contributors may be used to endorse or promote
# products derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)

FIND_PATH(SDL2_INCLUDE_DIR SDL.h
    HINTS
    ${SDL2}
    $ENV{SDL2}
    PATH_SUFFIXES include/SDL2 include SDL2
    i686-w64-mingw32/include/SDL2
    x86_64-w64-mingw32/include/SDL2
    PATHS
    ~/Library/Frameworks
    /Library/Frameworks
    /usr/local/include/SDL2
    /usr/include/SDL2
    /sw # Fink
    /opt/local # DarwinPorts
    /opt/csw # Blastwave
    /opt
)

# Lookup the 64 bit libs on x64
IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_LIBRARY_TEMP SDL2
        HINTS
        ${SDL2}
        $ENV{SDL2}
        PATH_SUFFIXES lib64 lib
        lib/x64
        x86_64-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
# On 32bit build find the 32bit libs
ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_LIBRARY_TEMP SDL2
        HINTS
        ${SDL2}
        $ENV{SDL2}
        PATH_SUFFIXES lib
        lib/x86
        i686-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)

IF(NOT SDL2_BUILDING_LIBRARY)
    IF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
        # Non-OS X framework versions expect you to also dynamically link to
        # SDL2main. This is mainly for Windows and OS X. Other (Unix) platforms
        # seem to provide SDL2main for compatibility even though they don't
        # necessarily need it.
        # Lookup the 64 bit libs on x64
        IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
            FIND_LIBRARY(SDL2MAIN_LIBRARY
                NAMES SDL2main
                HINTS
                ${SDL2}
                $ENV{SDL2}
                PATH_SUFFIXES lib64 lib
                lib/x64
                x86_64-w64-mingw32/lib
                PATHS
                /sw
                /opt/local
                /opt/csw
                /opt
                )
            # On 32bit build find the 32bit libs
        ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
            FIND_LIBRARY(SDL2MAIN_LIBRARY
                NAMES SDL2main
                HINTS
                ${SDL2}
                $ENV{SDL2}
                PATH_SUFFIXES lib
                lib/x86
                i686-w64-mingw32/lib
                PATHS
                /sw
                /opt/local
                /opt/csw
                /opt
                )
        ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)
    ENDIF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
ENDIF(NOT SDL2_BUILDING_LIBRARY)

# SDL2 may require threads on your system.
# The Apple build may not need an explicit flag because one of the
# frameworks may already provide it.
# But for non-OSX systems, I will use the CMake Threads package.
IF(NOT APPLE)
    FIND_PACKAGE(Threads)
ENDIF(NOT APPLE)

# MinGW needs an additional library, mwindows
# It's total link flags should look like -lmingw32 -lSDL2main -lSDL2 -lmwindows
# (Actually on second look, I think it only needs one of the m* libraries.)
IF(MINGW)
    SET(MINGW32_LIBRARY mingw32 CACHE STRING "mwindows for MinGW")
ENDIF(MINGW)

SET(SDL2_FOUND "NO")
    IF(SDL2_LIBRARY_TEMP)
        # For SDL2main
        IF(NOT SDL2_BUILDING_LIBRARY)
            IF(SDL2MAIN_LIBRARY)
                SET(SDL2_LIBRARY_TEMP ${SDL2MAIN_LIBRARY} ${SDL2_LIBRARY_TEMP})
            ENDIF(SDL2MAIN_LIBRARY)
        ENDIF(NOT SDL2_BUILDING_LIBRARY)

        # For OS X, SDL2 uses Cocoa as a backend so it must link to Cocoa.
        # CMake doesn't display the -framework Cocoa string in the UI even
        # though it actually is there if I modify a pre-used variable.
        # I think it has something to do with the CACHE STRING.
        # So I use a temporary variable until the end so I can set the
        # "real" variable in one-shot.
        IF(APPLE)
            SET(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} "-framework Cocoa")
        ENDIF(APPLE)

        # For threads, as mentioned Apple doesn't need this.
        # In fact, there seems to be a problem if I used the Threads package
        # and try using this line, so I'm just skipping it entirely for OS X.
        IF(NOT APPLE)
            SET(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} ${CMAKE_THREAD_LIBS_INIT})
        ENDIF(NOT APPLE)

        # For MinGW library
        IF(MINGW)
            SET(SDL2_LIBRARY_TEMP ${MINGW32_LIBRARY} ${SDL2_LIBRARY_TEMP})
        ENDIF(MINGW)

        # Set the final string here so the GUI reflects the final state.
        SET(SDL2_LIBRARY ${SDL2_LIBRARY_TEMP} CACHE STRING "Where the SDL2 Library can be found")
        # Set the temp variable to INTERNAL so it is not seen in the CMake GUI
        SET(SDL2_LIBRARY_TEMP "${SDL2_LIBRARY_TEMP}" CACHE INTERNAL "")

        SET(SDL2_FOUND "YES")
ENDIF(SDL2_LIBRARY_TEMP)

INCLUDE(FindPackageHandleStandardArgs)

FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2 REQUIRED_VARS SDL2_LIBRARY SDL2_INCLUDE_DIR)

找到SDL2_ttf.cmake

# Locate SDL2_ttf library
# This module defines
# SDL2_TTF_LIBRARY, the name of the library to link against
# SDL2_TTF_FOUND, if false, do not try to link to SDL2_ttf
# SDL2_TTF_INCLUDE_DIR, where to find SDL_image.h
#
# Additional Note: If you see an empty SDL2_TTF_LIBRARY_TEMP in your configuration
# and no SDL2_TTF_LIBRARY, it means CMake did not find your SDL2_Image library
# (SDL2_ttf.dll, libsdl2_image.so, SDL2_ttf.framework, etc).
# Set SDL2_TTF_LIBRARY_TEMP to point to your SDL2 library, and configure again.
# Similarly, if you see an empty SDL2MAIN_LIBRARY, you should set this value
# as appropriate. These values are used to generate the final SDL2_TTF_LIBRARY
# variable, but when these values are unset, SDL2_TTF_LIBRARY does not get created.
#
# $SDL2 is an environment variable that would
# correspond to the ./configure --prefix=$SDL2
# used in building SDL2.
# l.e.galup 9-20-02
#
# Modified by Eric Wing.
# Added code to assist with automated building by using environmental variables
# and providing a more controlled/consistent search behavior.
# Added new modifications to recognize OS X frameworks and
# additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL2 guidelines.
# Added a search for SDL2main which is needed by some platforms.
# Added a search for threads which is needed by some platforms.
# Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# SDL2_TTF_LIBRARY to override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL2/SDL.h to just SDL.h
# This needed to change because "proper" SDL2 convention
# is #include "SDL.h", not <SDL2/SDL.h>. This is done for portability
# reasons because not all systems place things in SDL2/ (see FreeBSD).
#
# Ported by Johnny Patterson. This is a literal port for SDL2 of the FindSDL.cmake
# module with the minor edit of changing "SDL" to "SDL2" where necessary. This
# was not created for redistribution, and exists temporarily pending official
# SDL2 CMake modules.
# 
# Note that on windows this will only search for the 32bit libraries, to search
# for 64bit change x86/i686-w64 to x64/x86_64-w64

#=============================================================================
# Copyright 2003-2009 Kitware, Inc.
#
# CMake - Cross Platform Makefile Generator
# Copyright 2000-2014 Kitware, Inc.
# Copyright 2000-2011 Insight Software Consortium
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# * Neither the names of Kitware, Inc., the Insight Software Consortium,
# nor the names of their contributors may be used to endorse or promote
# products derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)

FIND_PATH(SDL2_TTF_INCLUDE_DIR SDL_ttf.h
    HINTS
    ${SDL2}
    $ENV{SDL2}
    $ENV{SDL2_TTF}
    PATH_SUFFIXES include/SDL2 include SDL2
    i686-w64-mingw32/include/SDL2
    PATHS
    ~/Library/Frameworks
    /Library/Frameworks
    /usr/local/include/SDL2
    /usr/include/SDL2
    /sw # Fink
    /opt/local # DarwinPorts
    /opt/csw # Blastwave
    /opt
)

# Lookup the 64 bit libs on x64
IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_TTF_LIBRARY_TEMP
        NAMES SDL2_ttf
        HINTS
        ${SDL2}
        $ENV{SDL2}
        $ENV{SDL2_TTF}
        PATH_SUFFIXES lib64 lib
        lib/x64
        x86_64-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
# On 32bit build find the 32bit libs
ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_TTF_LIBRARY_TEMP
        NAMES SDL2_ttf
        HINTS
        ${SDL2}
        $ENV{SDL2}
        $ENV{SDL2_TTF}
        PATH_SUFFIXES lib
        lib/x86
        i686-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)

SET(SDL2_TTF_FOUND "NO")
    IF(SDL2_TTF_LIBRARY_TEMP)
    # Set the final string here so the GUI reflects the final state.
    SET(SDL2_TTF_LIBRARY ${SDL2_TTF_LIBRARY_TEMP} CACHE STRING "Where the SDL2_ttf Library can be found")
    # Set the temp variable to INTERNAL so it is not seen in the CMake GUI
    SET(SDL2_TTF_LIBRARY_TEMP "${SDL2_TTF_LIBRARY_TEMP}" CACHE INTERNAL "")
    SET(SDL2_TTF_FOUND "YES")
ENDIF(SDL2_TTF_LIBRARY_TEMP)

INCLUDE(FindPackageHandleStandardArgs)

FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2_TTF REQUIRED_VARS SDL2_TTF_LIBRARY SDL2_TTF_INCLUDE_DIR)

找到SDL2_image.cmake

# Locate SDL2_image library
# This module defines
# SDL2_IMAGE_LIBRARY, the name of the library to link against
# SDL2_IMAGE_FOUND, if false, do not try to link to SDL2_image
# SDL2_IMAGE_INCLUDE_DIR, where to find SDL_image.h
#
# Additional Note: If you see an empty SDL2_IMAGE_LIBRARY_TEMP in your configuration
# and no SDL2_IMAGE_LIBRARY, it means CMake did not find your SDL2_Image library
# (SDL2_image.dll, libsdl2_image.so, SDL2_image.framework, etc).
# Set SDL2_IMAGE_LIBRARY_TEMP to point to your SDL2 library, and configure again.
# Similarly, if you see an empty SDL2MAIN_LIBRARY, you should set this value
# as appropriate. These values are used to generate the final SDL2_IMAGE_LIBRARY
# variable, but when these values are unset, SDL2_IMAGE_LIBRARY does not get created.
#
# $SDL2 is an environment variable that would
# correspond to the ./configure --prefix=$SDL2
# used in building SDL2.
# l.e.galup 9-20-02
#
# Modified by Eric Wing.
# Added code to assist with automated building by using environmental variables
# and providing a more controlled/consistent search behavior.
# Added new modifications to recognize OS X frameworks and
# additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL2 guidelines.
# Added a search for SDL2main which is needed by some platforms.
# Added a search for threads which is needed by some platforms.
# Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# SDL2_IMAGE_LIBRARY to override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL2/SDL.h to just SDL.h
# This needed to change because "proper" SDL2 convention
# is #include "SDL.h", not <SDL2/SDL.h>. This is done for portability
# reasons because not all systems place things in SDL2/ (see FreeBSD).
#
# Ported by Johnny Patterson. This is a literal port for SDL2 of the FindSDL.cmake
# module with the minor edit of changing "SDL" to "SDL2" where necessary. This
# was not created for redistribution, and exists temporarily pending official
# SDL2 CMake modules.
# 
# Note that on windows this will only search for the 32bit libraries, to search
# for 64bit change x86/i686-w64 to x64/x86_64-w64

#=============================================================================
# Copyright 2003-2009 Kitware, Inc.
#
# CMake - Cross Platform Makefile Generator
# Copyright 2000-2014 Kitware, Inc.
# Copyright 2000-2011 Insight Software Consortium
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# * Neither the names of Kitware, Inc., the Insight Software Consortium,
# nor the names of their contributors may be used to endorse or promote
# products derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)

FIND_PATH(SDL2_IMAGE_INCLUDE_DIR SDL_image.h
    HINTS
    ${SDL2}
    $ENV{SDL2}
    $ENV{SDL2_IMAGE}
    PATH_SUFFIXES include/SDL2 include SDL2
    i686-w64-mingw32/include/SDL2
    x86_64-w64-mingw32/include/SDL2
    PATHS
    ~/Library/Frameworks
    /Library/Frameworks
    /usr/local/include/SDL2
    /usr/include/SDL2
    /sw # Fink
    /opt/local # DarwinPorts
    /opt/csw # Blastwave
    /opt
)

# Lookup the 64 bit libs on x64
IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_IMAGE_LIBRARY_TEMP
        NAMES SDL2_image
        HINTS
        ${SDL2}
        $ENV{SDL2}
        $ENV{SDL2_IMAGE}
        PATH_SUFFIXES lib64 lib
        lib/x64
        x86_64-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
# On 32bit build find the 32bit libs
ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_IMAGE_LIBRARY_TEMP
        NAMES SDL2_image
        HINTS
        ${SDL2}
        $ENV{SDL2}
        $ENV{SDL2_IMAGE}
        PATH_SUFFIXES lib
        lib/x86
        i686-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)

SET(SDL2_IMAGE_FOUND "NO")
    IF(SDL2_IMAGE_LIBRARY_TEMP)
    # Set the final string here so the GUI reflects the final state.
    SET(SDL2_IMAGE_LIBRARY ${SDL2_IMAGE_LIBRARY_TEMP} CACHE STRING "Where the SDL2_image Library can be found")
    # Set the temp variable to INTERNAL so it is not seen in the CMake GUI
    SET(SDL2_IMAGE_LIBRARY_TEMP "${SDL2_IMAGE_LIBRARY_TEMP}" CACHE INTERNAL "")
    SET(SDL2_IMAGE_FOUND "YES")
ENDIF(SDL2_IMAGE_LIBRARY_TEMP)

INCLUDE(FindPackageHandleStandardArgs)

FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2_IMAGE REQUIRED_VARS SDL2_IMAGE_LIBRARY SDL2_IMAGE_INCLUDE_DIR)

以下是生成文件，然后是我尝试过的一些不同方法。我从 makefile 中删除了一些不相关的代码以使其更加清晰，请参阅完整代码 on GitHub .

#CPP = clang++
#C = clang
CPP = g++
C = gcc

### Macintosh

LDFLAGS = -L/Library/Frameworks/SDL2.framework \
-L/Library/Frameworks/SDL2_ttf.framework \
-L/Library/Frameworks/SDL2_image.framework \
-lSDL2 -lSDL2_image -lSDL2_ttf
CFLAGS = -I/Library/Frameworks/SDL2.framework/Headers \
-I/Library/Frameworks/SDL2_ttf.framework/Headers \
-I/Library/Frameworks/SDL2_image.framework/Headers \
-Wall -c -std=c89
EXE1 = kiss_example1
EXE2 = kiss_example2

### Linux

#LDFLAGS = -lSDL2 -lSDL2_image -lSDL2_ttf
#CFLAGS = -Wall -c -std=c89
#EXE1 = kiss_example1
#EXE2 = kiss_example2

all: $(EXE1) $(EXE2)

$(EXE1): kiss_example1.o kiss_widgets.o kiss_draw.o kiss_general.o \
kiss_posix.o
    $(C) $^ $(LDFLAGS) -o $@

$(EXE2): kiss_example2.o kiss_widgets.o kiss_draw.o kiss_general.o \
kiss_posix.o
    $(C) $^ $(LDFLAGS) -o $@

kiss_example1.o: kiss_example1.c
    $(C) $(CFLAGS) $^ -o $@

kiss_example2.o: kiss_example2.c
    $(C) $(CFLAGS) $^ -o $@

kiss_widgets.o: kiss_widgets.c
    $(C) $(CFLAGS) $^ -o $@

kiss_draw.o: kiss_draw.c
    $(C) $(CFLAGS) $^ -o $@

kiss_general.o: kiss_general.c
    $(C) $(CFLAGS) $^ -o $@

kiss_posix.o: kiss_posix.c
    $(C) $(CFLAGS) $^ -o $@

clean:
    rm *.o && rm $(EXE1) && rm $(EXE2)
#   del *.o
#   del $(EXE1)
#   del $(EXE2)

1.

LDFLAGS = -framework SDL -framework SDL_ttf -framework SDL_image
CFLAGS = -framework SDL -framework SDL_ttf -framework SDL_image \
-Wall -c -std=c89
EXE1 = kiss_example1
EXE2 = kiss_example2

2.

LDFLAGS = -framework SDL -framework SDL_ttf -framework SDL_image
CFLAGS = -framework SDL -framework SDL_ttf -framework SDL_image \
-I/Library/Frameworks/SDL2.framework/Headers \
-I/Library/Frameworks/SDL2_ttf.framework/Headers \
-I/Library/Frameworks/SDL2_image.framework/Headers \
-Wall -c -std=c89
EXE1 = kiss_example1
EXE2 = kiss_example2

3.

LDFLAGS = -framework SDL -framework SDL_ttf -framework SDL_image
CFLAGS = -Wall -c -std=c89
EXE1 = kiss_example1
EXE2 = kiss_example2

我正在尝试构建的完整项目是 KISS_SDL，可以在 on GitHub 中找到它.

Answer 1

CMake 和 make 服务于完全不同但相关的目的。 CMake 根据各种CMakeLists.txt 文件给出的要求分析其运行的系统，并构造一个Makefile。然后，您通过 make 执行实际构建。 CMake 的作用类似于传统的configure 脚本，尤其类似于 GNU Autoconf 生成的配置脚本。

那么 CMake 是如何发现 SDL2 header 的位置的呢？它在系统某处有一个小脚本，知道如何执行此操作。几个，实际上。 (其中数百个包含在 CMake 安装中，软件分销商也可以提供他们自己的。)它可能使用 pkg-config，因为其他答案建议您自己做，或者它可能会测试几个常见的位置，或者它可能使用一些其他设施。您的 CMakeLists.txt 调用其中三个并指示 CMake 如何使用这些行的结果:

find_package(SDL2 REQUIRED)
include_directories(${SDL2_INCLUDE_DIR})

find_package(SDL2_ttf REQUIRED)
include_directories(${SDL2_TTF_INCLUDE_DIR})

find_package(SDL2_image REQUIRED)
include_directories(${SDL2_IMAGE_INCLUDE_DIR})

您可能可以通过检查相应的 cmake 脚本来确定 CMake 实际在做什么。在我的 Linux 系统上，它们将是

/usr/share/cmake/Modules/FindSDL.cmake
/usr/share/cmake/Modules/FindSDL_ttf.cmake
/usr/share/cmake/Modules/FindSDL_image.cmake

您可以在 Mac 上找到它们的位置取决于 CMake 的安装方式的详细信息。

或者，您可以检查 CMake 生成的 Makefile。它会比你的复杂得多，但你应该能够确定哪些标志被传递给编译器和链接器。