The previous version added -jN to the make invokation if UNIX
was set, but this was true also when cross compiling.
What we are actually interested in is CMAKE_HOST_UNIX, i.e.
whether the build host is UNIX.
Or we should check more exactly what CMAKE_MAKE_PROGRAM is.
Alex
Add an architecture-specific library directory path suffix for each
component. Use different search path for SDL_sound. Project files in
VisualC directory suggest that a win32lib will hold the libraries.
Reported-by: Paul Hampson <Paul.Hampson@Pobox.com>
This variable can be useful in cross-compiling contexts where the
sysroot is read-only or where the sysroot should otherwise remain
pristine.
If the new CMAKE_STAGING_PREFIX variable is set, it is used instead
of CMAKE_INSTALL_PREFIX when generating the installation rules in
cmake_install.cmake.
This way, the CMAKE_INSTALL_PREFIX variable
always refers to the installation prefix on the target device, regardless
of whether host==target.
If any -rpath paths passed to the linker contain the CMAKE_STAGING_PREFIX,
the matching path fragments are replaced with the CMAKE_INSTALL_PREFIX.
Matching paths in the -rpath-link are not transformed.
The cross-prefix usr-move workaround is assumed not to require extension
regarding CMAKE_STAGING_PREFIX. The staging area is a single prefix, so
there is no scope for cross-prefix symlinks. The CMAKE_INSTALL_PREFIX
is still used to determine the workaround path, and that variable
remains the relevant one even if CMAKE_STAGING_PREFIX is used. If the
generated export files are deployed to the target, the workaround
will still be in place, and still be employed if required.
7cd65c9 Add CMAKE_SYSROOT variable to set --sysroot when cross compiling.
5096967 Allow toolchain files to specify an external toolchain.
76552d5 Add compiler target compile options.
f41ecd1 CMakeDetermineCompilerId: Look for internal file only on host
As CMAKE_ROOT_FIND_PATH can be a list, a new CMAKE_SYSROOT is
introduced, which is never a list.
The contents of this variable is passed to supporting compilers
as --sysroot. It is also accounted for when processing implicit
link directories reported by the compiler, and when generating
RPATH information.
Clang can compile code, but uses the gcc tools for other tasks such
as linking. The -gcc-toolchain option can be used for that, but
generalize so that other compilers can be treated the same.
If such a location is specified, use it as a hint for finding
the binutils executables.
For clang, this allows passing -target <triple> to the compiler, and
for qcc, -V<arch> using toolchain files containing something like
set(triple arm-linux-gnueabihf)
set(CMAKE_C_COMPILER "/usr/bin/clang")
set(CMAKE_C_COMPILER_TARGET ${triple})
set(CMAKE_CXX_COMPILER "/usr/bin/clang++")
set(CMAKE_CXX_COMPILER_TARGET ${triple})
or
set(arch gcc_ntoarmv7le)
set(CMAKE_C_COMPILER /opt/qnx650/host/linux/x86/usr/bin/qcc)
set(CMAKE_C_COMPILER_TARGET ${arch})
set(CMAKE_CXX_COMPILER /opt/qnx650/host/linux/x86/usr/bin/QCC)
set(CMAKE_CXX_COMPILER_TARGET ${arch})
Both clang and qcc are inherently cross compiler( driver)s.
When cross-compiling with clang, use the CMAKE_${lang}_COMPILER_TARGET
as the _CMAKE_TOOLCHAIN_PREFIX to find the appropriate binutils.
When cross-compiling with QNX qcc, use the CMAKE_${lang}_COMPILER_TARGET
to set the appropriate _CMAKE_TOOLCHAIN_PREFIX.
The find_file this module uses to locate the compiler id source file
must always look on the host and never in CMAKE_FIND_ROOT_PATH, even
when a toolchain file has
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
Add NO_CMAKE_FIND_ROOT_PATH to the find_file call to avoid rerooting.
4cce44b Help: Document the CMAKE_MAKE_PROGRAM variable in more detail
558c74d VS: Switch to internal CMAKE_MAKE_PROGRAM lookup by generators
5229f2d Tests: Do not use an explicit make program for VS generators
72dd738 Tests: Fix MFC test heuristic for empty CMAKE_TEST_MAKEPROGRAM
fd6076d Tests: Pass CMAKE_MAKE_PROGRAM instead of --build-makeprogram
68031ab Tests: Configure SubProject-Stage2 test more robustly
003d10c Tests: Simplify VSExcludeFromDefaultBuild configuration
e47d934 Tests: Simplify VSProjectInSubdir configuration
e965cb1 Tests: Simplify CTest.BuildCommand.ProjectInSubdir configuration
72bf255 Tests: Pass --build-options to every test
4d1d772 ctest: Teach --build-options to allow zero options
96966b5 ctest: Make the --build-makeprogram optional for --build-and-test
91a0211 Simplify some calls to cmGlobalGenerator::Build
123a060 Teach GenerateBuildCommand to find its own make program
5f5c92b VS: Add internal APIs to find MSBuild, devenv/VCExpress, and msdev
4ac75fd Prefer CMAKE_MAKE_PROGRAM over CMAKE_BUILD_TOOL (#14548)
...
Manually revise the .rst format of the documentation. Use inline
literal quotes appropriately in paragraph text. Move the :: literal
block openers to the end of the preceding paragraphs. Convert the
command signature documentation and examples to cmake code-block
directives.
Drop the "Modules/CMakeVS*FindMake.cmake" files. Override the
cmGlobalGenerator::FindMakeProgram method for VS generators to use their
internal APIs to locate the build tool. Set the CMAKE_MAKE_PROGRAM as a
normal variable for use by project code, but do not cache it. This will
allow CMake and CTest to select the proper tool at build time.
Historically these were both added for the Makefile and Visual Studio
generators, respectively. Later the VS generators started using the
CMAKE_MAKE_PROGRAM cache entry to find the IDE build tool, and the
CMAKE_BUILD_TOOL was simply set as an alias.
Fix the documentation to explain that CMAKE_MAKE_PROGRAM is the modern
variable and that CMAKE_BUILD_TOOL is the compatibility alias, not the
other way around. Replace uses of CMAKE_BUILD_TOOL with
CMAKE_MAKE_PROGRAM in CMake-provided modules. Nothing needs to lookup
CMAKE_BUILD_TOOL in the cache, so simply set it as a normal variable.
The internal variables CPACK_ADDCOMP_COMPONENTS,
CPACK_ADDCOMP_STR and CPACK_ADDCOMP_UNAME were being needlessly
exported to CPackConfig.cmake.
Prefixing them with an underscore prevents this.
CPACK_ADDCOMP_STR was particularily problematic since it contains
unescaped quotes.
Since commit 7d47c693 (Drop compatibility with CMake < 2.4, 2013-10-08)
we no longer need to use the configure_file IMMEDIATE option to support
compatibility modes less than 2.0.
Allow ExternalData_URL_TEMPLATES to be empty if a value for
ExternalData_OBJECT_STORES is provided. Assume in this use case that
the object stores will already contain all needed objects. Extend the
Module.ExternalData test to cover this case (all objects in stores).
Extend the RunCMake.ExternalData test to cover the non-failure message
case when stores are provided without URL templates.
Manually revise the .rst format of the documentation. Use inline
literal quotes appropriately in paragraph text. Move the :: literal
block openers to the end of the preceding paragraphs. Convert the
command signature documentation and examples to cmake code-block
directives.
On biarch architecture, CMAKE_SYSTEM_PROCESSOR might be a 64bit one
while the system 32bit one. Take this into consideration while looking
for Java library directory.
Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=718290
The set() call for this variable left out the CACHE keyword. It does
not need to be cached anyway, so drop the other CACHE set() signature
arguments.
Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=722475
Reported-by: Modestas Vainius <modax@debian.org>
Inspired-by: Mathieu Malaterre <malat@debian.org>
As mentioned in commit 4693cf84 (Xcode: Detect new default locations of
Xcode 4.3 bits and pieces) PackageMaker was split out of Xcode 4.3 and
above into a separate Auxiliary tools package. Since Xcode 5.0 or so,
Apple no longer distributes PackageMaker as part of the available
development tools so it can only be obtained from old packages.
Disable the CPACK_BINARY_PACKAGEMAKER option by default as is the case
for most other tool-dependent generators.
In certain scenarios, it is preferable to keep a 'dirty' install prefix
than to clear it, and to expect that content will not be found there.
Add a CMAKE_FIND_NO_INSTALL_PREFIX variable that can be set to disable
searching the install prefix.
9c87d9c Add automatic rcc invocation for Qt.
84218e1 Add automatic uic invocation for Qt.
94a0ca6 Record which files are skipped by automoc.
18fb758 Run the main executable created in the autogen tests.
e485ba1 Rename the QtAutomoc tests to QtAutogen.
7ce65c3 Add extra checks for the AUTOMOC target property.
32771fc Update output messages for generic use.
f371ab5 Rename RunAutomoc to RunAutogen.
85b3d6e Extract an SetupAutoMocTarget method.
ca124a1 Rename the AutomocInfo.cmake file to be more generic.
a342c9f Move some makefile definitions up away from moc-specific code.
98632ef Add the AUTOGEN_TARGETS_FOLDER and obsolete AUTOMOC_TARGETS_FOLDER.
63378ba Rename some variables to reflect broader scope.
97f1aa3 Rename method to reflect generic use.
4abb111 Rename local variable to reflect generic use.
03878c9 Move variable set to where it is used.
...
3e04946 Require CMAKE_<LANG>_COMPILER to be found as a full path
6007f7c CMakeDetermineCompilerId: Always use compiler detected from IDE
332771c CMakeDetermine*Compiler: Remove temporary cache entry
All generators now support detection of the full path to the compiler, so
require it to be so. This will allow CMake<LANG>Information.cmake and
other logic to assume the full path to the compiler tool is available.
The Makefile generators already rejected CMAKE_<LANG>_COMPILER values
that did not name an existing compiler. Extend this error message to
all generators, make it occur as early as possible, and improve the
message with advice about how to set the compiler. If the full path to
the compiler is not known, finish enabling languages with a fatal error
so configuration does not continue.
For now, allow the RC language compiler to not be a full path. Later we
will need to detect the full path to "rc" under the VS IDE.
Add a RunCMake.CompilerNotFound test to cover failure cases.
Fix the RunCMake.CompilerChange test EmptyCompiler case to work
when configuration does not continue past enable_language.
When compiler id detection also provides a CMAKE_<LANG>_COMPILER
value, use it unconditionally. It is known to be the compiler
that is actually in use by IDE builds in VS and Xcode. Do not
let a stray cache entry try to say otherwise.
Teach the ctest_update implementation to use the p4 command-line
client to perform updates and extract the list of changes.
Add a CTest.UpdateP4 test like those that exist already for the other
version control tools. Make the test available when p4 and the p4d
server are found. During the test launch p4d in the background to
serve a repository from the test directory. Then direct the client
toward this server for the duration of the test.
One way to use clang as a cross-compiler is to create
a symlink named <target>-clang, which is equivalent to
running
clang -target <target>
Extract the toolchain prefix to find the binutils executables.
When the user or toolchain file sets CMAKE_<LANG>_COMPILER to a name
without a path we use find_program with CMAKE_<LANG>_COMPILER_WITH_PATH
to search for the tool. Remove the temporary cache entry afterward to
avoid exposing it to projects. It is not set by other logic paths so no
one should be using it.
The source files are already processed by cmQtAutomoc to look for
moc includes, so extend that to also look for ui_ includes and
find corresponding .ui files to process.
This replaces the need to invoke qt4_wrap_ui().
As the ui files are not likely to be part of the SOURCES of the
target, store the options associated with them separately in the
cmMakefile for querying during the autogen run.
* added CUDA_TOOLKIT_TARGET_DIR CMake variable that used
to locate headers and libraries for target platform
* added CUDA_TARGET_CPU_ARCH which is set to ARM for
arm cross-compilation and is used to add
--target-cpu-architecture NVCC flag
Drop all behavior activated by setting CMAKE_BACKWARDS_COMPATIBILITY to
a value lower than 2.4, and generate an error when projects or the user
attempt to do so. In the error suggest using a CMake 2.8.x release.
Teach cmake_minimum_required to warn about projects that do not require
at least CMake 2.4. They are not supported by CMake >= 3.0.
Replace the documentation of CMAKE_BACKWARDS_COMPATIBILITY with a
reference to policy CMP0001.
Even though this variable gets set to CMAKE_<LANG>_COMPILER-NOTFOUND when
the compiler is not found, CMake<LANG>Compiler.cmake gets removed by
cmGlobalGenerator::EnableLanguage so in try compiles the value is empty.
Quote references to the variable in
Modules/CMake(C|CXX|Fortran)Information.cmake
Modules/CMakeDetermineCompilerId.cmake
to avoid dropping arguments from commands that expect them.
Add "Module Documentation" and "Find Modules" subsections. Add to
Modules/readme.txt a textual reference to the cmake-developer.7 manual
and, while at it, fix the wiki URL domain.
Move all content from Modules/readme.txt except for the link to the
module maintainers wiki page into "Help/manual/cmake-developer.7.rst".
This produces some invalid reStructuredText markup to be fixed in a
future commit.
Previously if headers required to check the size of a type can be
compiled with C++ compiler only, the check would fail because the C
compiler fails. As a consequence, HAVE_${VARIABLE} would be set to
false, and ${VARIABLE} will be empty.
Teach CHECK_TYPE_SIZE to accept a new optional argument LANGUAGE
that allows one to explicitly set the compiler to use. The new
signature is therefore:
CHECK_TYPE_SIZE(TYPE VARIABLE [BUILTIN_TYPES_ONLY]
[LANGUAGE <language>])
Teach CMakeDetermineCompilerId to skip trying to build a .vfproj
file for Intel Fortran under Visual Studio 6. The msdev command-line
build produces a popup error dialog that hangs the configuration.
In generators such as Ninja that can run multiple "cl" processes that
refer to the same compiler .pdb file (/Fd) at the same time, MSVC from
Visual Studio 2013 complains:
fatal error C1041: cannot open program database '.../vc120.pdb';
if multiple CL.EXE write to the same .PDB file, please use /FS
According to "cl /?":
/FS force to use MSPDBSRV.EXE
Add the flag to compilation lines for this compiler version just after the
/Fd option.
d14898b Intel: Fix detection of MSVC version simulated by pre-11.0 Fortran
a85e17e Intel: When simulating MSVC, re-use Windows-MSVC (#14476)
af40e8c VS: Detect Intel Fortran compiler id and version
b8522a8 VS: Expose Intel Fortran .vfproj format version to CMake language
2d36c9a CMakeDetermineCompilerId: Fix Intel Fortran compiler id detection
a6fd17c VS: Fix CMAKE_<LANG>_COMPILER detection with Intel toolset (#14471)
The Intel Fortran 10 64-bit compiler incorrectly defines _MSC_VER to its
own version (1020) instead of the underlying MSVC tools version. Since
we expect the compiler to be used only with VS >= 7 tools, assume MSVC
version 13.0 if _MSC_VER is not greater than 1300.
Teach CMake(C|CXX|Fortran)CompilerId* to report the MSVC version
simulated by the Intel compiler, if any. Refactor the Windows-Intel
platform information helper module to load Windows-MSVC instead of
duplicating the information. Teach Windows-MSVC to understand when
it is loaded as the simulated Fortran compiler (its preprocessor is
simulated).
It designed to search for implementation of backtrace(3) routine.
Currently it is used in OpenBSD Ports for building Clementine
music player.
A lot of input from brad.king@ and neundorf@.
The Intel Fortran compiler needs the /fpp option to enable C
preprocessing. Without the option the compiler may warn and ignore
preprocessor lines instead of failing with an error. Detect the
warning and treat it as failure so that we move on to try /fpp and
detect the correct id. Without this it works only by luck because
Intel is the first compiler id in our detection source file.
Drop #end and #module. Convert #section to a subsection header.
Convert #variable to the cmake domain "variable" directive.
Convert #macro to the cmake domain "command" directive.
Perform minor formatting fixes in text near these changes.
Compilers for languages other than C and C++ on OS X may not understand
the -F framework search flag. Create a new platform information
variable CMAKE_<LANG>_FRAMEWORK_SEARCH_FLAG to hold the flag, and set it
for C and CXX lanugages in the Platform/Darwin module.
Reported-by: Vittorio Giovara <vittorio.giovara@gmail.com>
f973737 GenerateExportHeader: Port to use message(DEPRECATION)
f69606d Qt4Macros: Port to use message(DEPRECATION)
509c142 message: Add a DEPRECATION mode
7efef02 FindGTK2: Add tests for components and targets in gtk and gtkmm modules
95fc47a FindGTK2: Make pangocairo and cairo optional dependencies
26f790f FindGTK2: Change extra includes -> optional
24e0272 FindGTK2: do not skip target creation if optional dependencies are not found
d5f130c FindGTK2: Refactor _GTK2_ADJUST_LIB_VARS into _GTK2_ADD_TARGET
fffbd72 FindGTK2: Do not add freetype includes if they are not found
b69720d FindGTK2: Add libraries to the GTK2_LIBRARIES variable only when found
425ec40 FindGTK2: Do not link libfreetype
e9f46df FindGTK2: Add config directories only if different from include ones
56a79e1 FindGTK2: Set INTERFACE_COMPILE_DEFINITIONS target property only if not empty
4b47586 FindGTK2: Add check to ensure that target exists
61242cc FindGTK2: Fix gmodule, glibmm, pangoft2, and pangoxft targets
4b876de FindGTK2: Link freetype libs to targets including freetype includes
67e761f FindGTK2: Small cleanup
682eea3 FindGTK2: Do not require the GTK_ prefix in all the internal functions
0bc3763 FindGTK2: Better handling of include directories
...
54ef2be Haiku: Include files cleanup in cmCTest
38d5555 Haiku: Remove outdated preprocessor checks
1dc61f8 Haiku: Remove use of B_COMMON_DIRECTORY
7ebc1cb Haiku: Several fixes to platform module
1763c31 Set policy CMP0025 to NEW while building CMake itself
aa53ee5 Add policy CMP0025 for Apple Clang compiler id compatibility
ab65862 Clang: Add separate "AppleClang" compiler id
3d8356d Clang: Support Windows variants for GNU and MSVC (#13035, #14458)
51ab85c CMakeDetermineCompilerId: Add notion of "simulated" id/version
be10826 CMakeDetermineCompilerId: Fix local var init
This function avoids creating the targets when the required
dependencies were not found.
Also fix some wrong dependency and some typo.
${FREETYPE_INCLUDE_DIR_ft2build} ${FREETYPE_INCLUDE_DIR_freetype2} are
now required for gtkmm component
Some libraries (e.g. gio) are not necessary, and often not available
with older GTK2 versions, therefore GTK_LIBRARIES should not contain
GTK2_XXX-NOT_FOUND for these libraries.
As discussed on the mailing list, freetype includes used in GTK2
headers libraries do not require to link the library explicitly (even
though it is already linked by GTK2 libraries.
Also remove _GTK2_ADD_TARGET_LIBRARIES no longer used and use
${FREETYPE_INCLUDE_DIR_ft2build} ${FREETYPE_INCLUDE_DIR_freetype2}
variables instead of ${FREETYPE_INCLUDE_DIRS}
Also add a comment explaining the purpose of the include/SDL* path
suffixes. As explained in commit 7cb51739 (FindSDL: Restore
accidentally dropped search paths (#13651), 2012-11-05) the include/SDL*
path suffixes are for looking in the ENV{SDLDIR} location.
Inspired-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
* Do not define BEOS anymore (this includes workarounds which we don't
need most of the time in Haiku, so we prefer opt-in IF(HAIKU) in the
cmake files instead).
* On the other hand, do define UNIX (we are trying to be compliant) and
HAIKU (there is still a number of things we don't do like the
average UNIX clone)
* Do not use UnixPaths, as our filesystem hierarchy isn't anything like
what it expects.
* Do not use -nostart, which the compiler doesn't know about anymore.
This used to be an Haiku extension to gcc, and is equivalent to
-shared which is the default gcc option.
* While "dl" functions are provided in libroot, this is always
implicitly linked so there is no need to tell cmake about it.
* Forcing position-independent code is not needed, so remove it.
* On the other hand, include appropriate linker options for executables
and shared libraries.
* Support for the two available compilers in Haiku (gcc2 and gcc4) and
pick the right headers and libraries according to the currently
selected one.
* With the adoption of the package manager, the directory layout was
changed. Tell cmake where to look for header files and libraries.
* As we don't define BEOS anymore, enable the workaround we still need
for HAIKU as well. This is the lack of a libm (it is part of the
implicitly linked in libroot)
Applied-by: Rolf Eike Beer <eike@sf-mail.de>
Previously if headers required to check if a struct has a member can be
compiled with C++ compiler only, the check would fail because the C
compiler fails. As a consequence, the result variable would be set to
false, even if the struct has that particular member.
Teach CHECK_STRUCT_HAS_MEMBER to accept a new optional argument LANGUAGE
that allows one to explicitly set the compiler to use. The new
signature is therefore:
CHECK_STRUCT_HAS_MEMBER (<struct> <member> <header> <variable>
[LANGUAGE <language>])
Apple distributes their own Clang build with their own version numbers
that differ from upstream Clang. Use the __apple_build_version__ symbol
to identify the Apple Clang compiler and report the Apple Build Version
as the fourth version component in CMAKE_<LANG>_COMPILER_VERSION. Add
Compiler/AppleClang-<lang> and Platform/Darwin-AppleClang-<lang> modules
that simply include the upstream equivalents.
Fix comparisons of CMAKE_<LANG>_COMPILER_ID to Clang in CMake's own
source and tests to account for AppleClang.
5f11b8d Eclipse: add version 4.3 for completeness
2b63734 Eclipse: print different message if CMAKE_ECLIPSE_VERSION is already set
1ff8c21 CMakeFindEclipse: use lowercase for macro calls
Teach the compiler identification preprocessor tests to report when
Clang simulates MSVC, and what version. If not MSVC, assume GNU.
Teach compiler information modules Clang-(C|CXX) to recognize when Clang
simulates MSVC and skip loading the GNU information.
Teach the Windows-MSVC platform information to recognize when it is
loaded as the simulated compiler and use that version information
instead of the real compiler's (different) version scheme.
Add platform modules Windows-Clang-(C|CXX) and support module
Windows-Clang to load either Windows-MSVC or Windows-GNU and wrap
the corresponding information macros.
Some compilers try to simulate other compilers as a drop-in replacement
supporting all the same command-line options and predefined preprocessor
macros. In such cases it will be useful to have CMake load the compiler
information files for the simulated compiler instead of duplicating the
information. Teach CMakeDetermineCompilerId to extract the simulated
compiler id and version when the compiler id detection provides it.
In Modules/Platform/Darwin.cmake set CMAKE_SYSTEM_FRAMEWORK_PATH to
include framework directories from inside the system SDK corresponding
to CMAKE_OSX_SYSROOT.
Suggested-by: Sean McBride <sean@rogue-research.com>
The subsystem must be set to WINDWOSCE for some SDKs to link an
executable. Set it to 9 for VS2005 and to 8 for VS2008, since the
value differs between the different Visual Studio versions.
In commit bd827f98 (Use COFF file header header for architecture
detection, 2013-08-05) the MSVC_<lang>_ARCHITECTURE_ID value computed by
CMakeDetermineCompilerId.cmake changed for WinCE architectures to be the
exact architecture read from the PE header. Fix platform preprocessor
definitions in Modules/Platform/Windows-MSVC.cmake to correspond to the
architecture family (ARM or SHx) instead of the specific architecture.
In commit 8fcf0ab0 (Add support for new Windows CE compiler, 2013-08-04)
we made corelibc conditional on the MSVC version, but the version value
was incorrect. Update it to use corelibc for VS 2008 and below.
When FindHDF5 was first added in commit e6734068 (Add HDF5 find
module..., 2009-08-24) it contained a workaround for a bug in
SelectLibraryConfigurations that did not transform lists correctly.
That bug was fixed by commit 5797512c (SelectLibraryConfiguration:
generate correct output when input vars are lists, 2012-07-28). Then
refactoring in commit 04d4dc33 (SelectLibraryConfigurations: Use
-NOTFOUND instead of copying the vars, 2013-07-08) changed undocumented
behavior on which the original workaround relied. The result puts
entries like HDF5_hdf5_LIBRARY_DEBUG-NOTFOUND in HDF5_LIBRARIES.
Fix this by dropping the original workaround since the underlying issue
has been fixed anyway. Use the HDF5_${LIB}_LIBRARY selected by the call
to select_library_configurations directly.
In commit 2a797539 (FindPNG: improve library detection, 2013-07-27) we
split the search for PNG into separate PNG_LIBRARY_DEBUG and
PNG_LIBRARY_RELEASE variables. However, if a project or user sets the
old PNG_LIBRARY value we must honor it instead of searching.
While at it, mark PNG_LIBRARY_RELEASE and PNG_LIBRARY_DEBUG as advanced
and remove a stray debug message.
Brad King
Stephen Kelly
Alex Neundorf
Julien Schueller
Daniele E. Domenichelli
Benjamin Eikel
Arnaud Desmier
Nils Gladitz
Clinton Stimpson
Rolf Eike Beer
Modestas Vainius
Peter Kümmel
Dragos Carp
Pedro Navarro
Matt McCormick
Vladislav Vinogradov
Kitware Robot
Vadim Zhukov
Leszek Swirski
Adrien Destugues
William Orr
Patrick Gansterer
Simon Levermann