FindGIF: Detect version from GIF 4.1.6 and above

GIF 4.1.6 introduced version macros in the header file.  Use them
to get a full version.

Fixes #16196.
This commit is contained in:
Ben Campbell 2016-07-13 15:05:47 +12:00 committed by Brad King
parent c8e59d2dfa
commit 0a6c227d64
1 changed files with 35 additions and 11 deletions

View File

@ -2,12 +2,18 @@
# FindGIF
# -------
#
# This finds the GIF library (giflib)
#
# The module defines the following variables:
#
# This module searches giflib and defines GIF_LIBRARIES - libraries to
# link to in order to use GIF GIF_FOUND, if false, do not try to link
# GIF_INCLUDE_DIR, where to find the headers GIF_VERSION, reports either
# version 4 or 3 (for everything before version 4)
# ``GIF_FOUND``
# True if giflib was found
# ``GIF_LIBRARIES``
# Libraries to link to in order to use giflib
# ``GIF_INCLUDE_DIR``
# where to find the headers
# ``GIF_VERSION``
# 3, 4 or a full version string (eg 5.1.4) for versions >= 4.1.6
#
# The minimum required version of giflib can be specified using the
# standard syntax, e.g. find_package(GIF 4)
@ -29,7 +35,7 @@
# License text for the above reference.)
# Created by Eric Wing.
# Modifications by Alexander Neundorf
# Modifications by Alexander Neundorf, Ben Campbell
find_path(GIF_INCLUDE_DIR gif_lib.h
HINTS
@ -61,22 +67,40 @@ set(GIF_LIBRARIES ${GIF_LIBRARY})
# to be always " Version 2.0, " in versions 3.x of giflib.
# In version 4 the member UserData was added to GifFileType, so we check for this
# one.
# http://giflib.sourcearchive.com/documentation/4.1.4/files.html
# Versions after 4.1.6 define GIFLIB_MAJOR, GIFLIB_MINOR, and GIFLIB_RELEASE
# see http://giflib.sourceforge.net/gif_lib.html#compatibility
if(GIF_INCLUDE_DIR)
include(${CMAKE_CURRENT_LIST_DIR}/CMakePushCheckState.cmake)
include(${CMAKE_CURRENT_LIST_DIR}/CheckStructHasMember.cmake)
CMAKE_PUSH_CHECK_STATE()
set(CMAKE_REQUIRED_QUIET ${GIF_FIND_QUIETLY})
set(GIF_VERSION 3)
set(CMAKE_REQUIRED_INCLUDES "${GIF_INCLUDE_DIR}")
CHECK_STRUCT_HAS_MEMBER(GifFileType UserData gif_lib.h GIF_GifFileType_UserData )
if(GIF_GifFileType_UserData)
set(GIF_VERSION 4)
# 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}.${_GIF_REL}")
else()
# use UserData field to sniff version instead
CHECK_STRUCT_HAS_MEMBER(GifFileType UserData gif_lib.h GIF_GifFileType_UserData )
if(GIF_GifFileType_UserData)
set(GIF_VERSION 4)
else()
set(GIF_VERSION 3)
endif()
endif()
unset(_GIF_MAJ)
unset(_GIF_MIN)
unset(_GIF_REL)
unset(_GIF_DEFS)
CMAKE_POP_CHECK_STATE()
endif()
# handle the QUIETLY and REQUIRED arguments and set GIF_FOUND to TRUE if
# all listed variables are TRUE
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)