Running the pnglibconf scripts (script/*.awk) is not always possible.
An AWK interpreter is not always guaranteed to be available; and even
if it is, there are limitations when making cross-platform libpng
builds, especially when the differences between the host platform and
the target platform are significant. For example:
* Building for the Windows (MinGW) target on a Unix development host;
* Building for the iOS target on a macOS development host;
* Building for the Android target on any development host.
In such scenarios, a preconfigured (i.e. prebuilt) pnglibconf.h file,
either taken from the libpng source tree or provided by the user who
wants to make a custom libpng build, becomes a necessity.
In this commit we introduce the build option `PNG_LIBCONF_HEADER` in
order to address this specific use case.
We also specify a version range (3.14...4.0) for the minimum required
CMake program, to future-proof the CMake build for just a little bit
longer.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
In preparation for the upcoming changes in the build system, any parts
of the CMake file that are unlikely to be affected should be moved out
of the way. This should facilitate an easier resync between the branch
'libpng16' and its successor(s).
Specifically:
* Move the functions `generate_chk`, `generate_out`, `generate_source`
and `generate_copy` to scripts/cmake/PNGGenConfig.cmake.
* Move the function `png_add_test` to scripts/cmake/PNGTest.cmake.
* Leave the function `create_symlink` in place, but add a TODO note.
As we raised the minimum required CMake version to 3.14, we should
now be able to use CMake's built-in function instead.
Introduce CMake file linting, based on the cmakelang project by
Josh Bialkowski (@cheshirekow).
Fix various style issues in the CMake files:
* Add the missing copyright header to PNGConfig.cmake.
* Resolve a "missing docstring" warning raised by cmake-lint.
* Rewrite all docstrings in the style of CMake's own documentation.
* Fix whitespace inconsistencies.
References:
* https://pypi.org/project/cmakelang
* https://github.com/cheshirekow/cmake_format
This is a cherry-pick of commit c317fe31114d92d05d44bf98c9b559edf4656b9c
from branch 'libpng18'.
Properly declare target include directories for generated includes.
Previously the non targeted `include_directories()` was used, which
had issue when using the `png_static` target in a submodule.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Properly declare target include directories for generated includes.
Previously the non targeted `include_directories()` was used, which
had issue when using the `png_static` target in a submodule.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Modern compilers can disable the warnings that originate from system
headers. This change allows them to do so with the libpng headers.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
This fixes commit 4edbb4da81626a7342a22824d7a8f60a3ea71bd0.
During the move of CMake scripts to the scripts/cmake/ subdirectory,
some of the workflows have been broken.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
From the libpng licensing point of view, the build projects, the build
scripts, the test scripts, the CI verification scripts, et cetera, have
not traditionally been part of libpng proper, although some of these,
including the CMake-based build, have been released under the libpng
license.
Considering how the CMake build grew as a result of many contributions
from many contributing authors over a long time, one may argue that it
almost became an individual piece of software in its own right.
Moving on, everything CMake-related shall be placed in the subdirectory
scripts/cmake/ (except, of course, the main CMakeLists.txt). Moreover,
contributing authors shall be acknowledged in scripts/cmake/AUTHORS.md.
Please see scripts/cmake/README.md for more information.
