tree dc1de7c6c11028cc0b00ec077f53f4c200a8d105
parent 3c67d4f7c0b8b59c127585b2120b00267d64c728
author DRC <information@libjpeg-turbo.org> 1461626206 -0500
committer DRC <information@libjpeg-turbo.org> 1461629176 -0500

CMakeLists.txt: Clarify that Un*x isn't supported

At one time, it was possible to use CMake to build under Cygwin, but
that hasn't worked since 1.4.1 (due to the Huffman codec changes that
now require SIZEOF_SIZE_T to be defined for non-WIN32 platforms) and may
have even been broken before that.  Originally, we used the "date"
command under MSYS in order to obtain the default build number, but that
was rendered unnecessary by 5e3bb3e9 (v1.3 beta.)  9fe22dac (1.4 beta)
further modified CMakeLists.txt so that the "date" command was only used
on Cygwin, but for unexplained reasons, that commit also applied the
(now vestigial) code to all non-WIN32 platforms.  This prevented
CMakeLists.txt from displaying an error if someone attempted to use the
CMake build system on Un*x platforms, and that may have been behind the
flurry of pull requests and issues-- including #21, #29, #37, #58, #73--
complaining that the CMake build system didn't work on Un*x platforms
(although it was not until #73 that this bug came to light.)

This commit removes all vestiges of Un*x support from the CMake build
system and makes it clear that CMake cannot be used to build
libjpeg-turbo on non-WIN32 platforms.  It is our position that CMake
will not be supported on non-WIN32 platforms until/unless the autotools
build system is removed, and this will not happen without broad support
from the community (including major O/S vendors.)  If you are in favor
of migrating the entire build system to CMake, then please make your
voice heard by commenting on #56.