CMake/Modules/FindGIF.cmake
Brad King 86578eccf2 Simplify CMake per-source license notices
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool.  Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience.  Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.

Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices.  It also references version control
history for more precise information.  Therefore we no longer need to spell
out the list of Contributors in each source file notice.

Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing".  The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.

Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically.  Manually fix up shebang lines and trailing
newlines in a few files.  Manually update the notices in a few files that the
script does not handle.
2016-09-27 15:14:44 -04:00

101 lines
3.1 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)
#
# The module defines the following variables:
#
# ``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)
#
# $GIF_DIR is an environment variable that would correspond to the
# ./configure --prefix=$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
PATHS
~/Library/Frameworks
/usr/freeware
)
# 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
PATHS
~/Library/Frameworks
/usr/freeware
)
# see readme.txt
set(GIF_LIBRARIES ${GIF_LIBRARY})
# Very basic version detection.
# The GIF_LIB_VERSION string in gif_lib.h seems to be unreliable, since it seems
# to be always " Version 2.0, " in versions 3.x of giflib.
# In version 4 the member UserData was added to GifFileType, so we check for this
# one.
# Versions after 4.1.6 define GIFLIB_MAJOR, GIFLIB_MINOR, and GIFLIB_RELEASE
# see http://giflib.sourceforge.net/gif_lib.html#compatibility
if(GIF_INCLUDE_DIR)
include(${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}.${_GIF_REL}")
else()
# use UserData field to sniff version instead
CHECK_STRUCT_HAS_MEMBER(GifFileType UserData gif_lib.h GIF_GifFileType_UserData )
if(GIF_GifFileType_UserData)
set(GIF_VERSION 4)
else()
set(GIF_VERSION 3)
endif()
endif()
unset(_GIF_MAJ)
unset(_GIF_MIN)
unset(_GIF_REL)
unset(_GIF_DEFS)
CMAKE_POP_CHECK_STATE()
endif()
# handle the QUIETLY and REQUIRED arguments and set GIF_FOUND to TRUE if
# all listed variables are TRUE
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(GIF REQUIRED_VARS GIF_LIBRARY GIF_INCLUDE_DIR
VERSION_VAR GIF_VERSION )
mark_as_advanced(GIF_INCLUDE_DIR GIF_LIBRARY)