CMake/Modules/FindGIF.cmake
Maximilian Heinzler 5bc64fe6c2 FindGIF: Modernize
This brings the module up to the current find module standards by adding
the GIF_INCLUDE_DIRS variable and the target GIF::GIF. It also updates
the documentation style to that of similar modules.
2018-11-20 21:07:03 +01:00

128 lines
3.7 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
FindGIF
-------
This finds the GIF library (giflib)
Imported targets
^^^^^^^^^^^^^^^^
This module defines the following :prop_tgt:`IMPORTED` target:
``GIF::GIF``
The giflib library, if found.
Result variables
^^^^^^^^^^^^^^^^
This module will set the following variables in your project:
``GIF_FOUND``
If false, do not try to use GIF.
``GIF_INCLUDE_DIRS``
where to find gif_lib.h, etc.
``GIF_LIBRARIES``
the libraries needed to use GIF.
``GIF_VERSION``
3, 4 or a full version string (eg 5.1.4) for versions >= 4.1.6.
Cache variables
^^^^^^^^^^^^^^^
The following cache variables may also be set:
``GIF_INCLUDE_DIR``
where to find the GIF headers.
``GIF_LIBRARY``
where to find the GIF library.
Hints
^^^^^
``GIF_DIR`` is an environment variable that would correspond to the
``./configure --prefix=$GIF_DIR``.
#]=======================================================================]
# Created by Eric Wing.
# Modifications by Alexander Neundorf, Ben Campbell
find_path(GIF_INCLUDE_DIR gif_lib.h
HINTS
ENV GIF_DIR
PATH_SUFFIXES include
)
# the gif library can have many names :-/
set(POTENTIAL_GIF_LIBS gif libgif ungif libungif giflib giflib4)
find_library(GIF_LIBRARY
NAMES ${POTENTIAL_GIF_LIBS}
HINTS
ENV GIF_DIR
PATH_SUFFIXES lib
)
# Very basic version detection.
# The GIF_LIB_VERSION string in gif_lib.h seems to be unreliable, since it seems
# to be always " Version 2.0, " in versions 3.x of giflib.
# In version 4 the member UserData was added to GifFileType, so we check for this
# one.
# Versions after 4.1.6 define GIFLIB_MAJOR, GIFLIB_MINOR, and GIFLIB_RELEASE
# see http://giflib.sourceforge.net/gif_lib.html#compatibility
if(GIF_INCLUDE_DIR)
include(${CMAKE_CURRENT_LIST_DIR}/CMakePushCheckState.cmake)
include(${CMAKE_CURRENT_LIST_DIR}/CheckStructHasMember.cmake)
CMAKE_PUSH_CHECK_STATE()
set(CMAKE_REQUIRED_QUIET ${GIF_FIND_QUIETLY})
set(CMAKE_REQUIRED_INCLUDES "${GIF_INCLUDE_DIR}")
# Check for the specific version defines (>=4.1.6 only)
file(STRINGS ${GIF_INCLUDE_DIR}/gif_lib.h _GIF_DEFS REGEX "^[ \t]*#define[ \t]+GIFLIB_(MAJOR|MINOR|RELEASE)")
if(_GIF_DEFS)
# yay - got exact version info
string(REGEX REPLACE ".*GIFLIB_MAJOR ([0-9]+).*" "\\1" _GIF_MAJ "${_GIF_DEFS}")
string(REGEX REPLACE ".*GIFLIB_MINOR ([0-9]+).*" "\\1" _GIF_MIN "${_GIF_DEFS}")
string(REGEX REPLACE ".*GIFLIB_RELEASE ([0-9]+).*" "\\1" _GIF_REL "${_GIF_DEFS}")
set(GIF_VERSION "${_GIF_MAJ}.${_GIF_MIN}.${_GIF_REL}")
else()
# use UserData field to sniff version instead
CHECK_STRUCT_HAS_MEMBER(GifFileType UserData gif_lib.h GIF_GifFileType_UserData )
if(GIF_GifFileType_UserData)
set(GIF_VERSION 4)
else()
set(GIF_VERSION 3)
endif()
endif()
unset(_GIF_MAJ)
unset(_GIF_MIN)
unset(_GIF_REL)
unset(_GIF_DEFS)
CMAKE_POP_CHECK_STATE()
endif()
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(GIF REQUIRED_VARS GIF_LIBRARY GIF_INCLUDE_DIR
VERSION_VAR GIF_VERSION )
if(GIF_FOUND)
set(GIF_INCLUDE_DIRS "${GIF_INCLUDE_DIR}")
set(GIF_LIBRARIES ${GIF_LIBRARY})
if(NOT TARGET GIF::GIF)
add_library(GIF::GIF UNKNOWN IMPORTED)
set_target_properties(GIF::GIF PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES "${GIF_INCLUDE_DIRS}")
if(EXISTS "${GIF_LIBRARY}")
set_target_properties(GIF::GIF PROPERTIES
IMPORTED_LINK_INTERFACE_LANGUAGES "C"
IMPORTED_LOCATION "${GIF_LIBRARY}")
endif()
endif()
endif()
mark_as_advanced(GIF_INCLUDE_DIR GIF_LIBRARY)