FindZLIB accepts various names for zlib (e.g. "z", "zlib", ...) in
various search locations. Before this patch zlib ignored the priority
implied by the search locations and instead prioritized based on the
library name. Consequently ensuring the pick of a zlib from e.g. a
CMAKE_PREFIX_PATH was not possible if it didn't have the highest
priority name ("z").
This unexpected behavior led to bugs in third party projects (e.g.
https://github.com/Microsoft/vcpkg/issues/1939). A common way to
encounter the issue in the wild is on Windows with the popular
Anaconda python distribution which puts a "z.lib" in a lib/
subdirectory reachable from a bin/ path in PATH. From then on cmake
will always pick up this library instead of the one intended by the
user.
This patch adds the NAMES_PER_DIR option to the find_library calls made
by FindZLIB making it search each directory for all names before
considering lower priority directory names resolving these issues.
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names and years are hard to maintain and often out-of-date or plain wrong.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.
We no longer define the ZLIB_LIBRARY cache entry, so we should not mark
it as advanced either. We only use this variable when someone else
defines it in order to remain compatible with older versions of this
module, but we never create the entry ourselves anymore.
Provide each variant in ZLIB_LIBRARIES and ZLIB::ZLIB imported location
properties when one is found, while maintaining support for manually
setting the library via ZLIB_LIBRARY.
Ancient versions of CMake required else(), endif(), and similar block
termination commands to have arguments matching the command starting the
block. This is no longer the preferred style.
Run the following shell code:
for c in else endif endforeach endfunction endmacro endwhile; do
echo 's/\b'"$c"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
egrep -z -v 'Tests/CMakeTests/While-Endwhile-' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed
Perform multiple separate searches in order. If ZLIB_ROOT is set search
it exclusively so it takes precedence over CMAKE_PREFIX_PATH. This
allows a user to provide -DZLIB_ROOT=/path/to/zlib/prefix on the CMake
command line to tell it exactly where to find zlib. Otherwise fall back
to a normal search.
Inspired-by: Andreas Schneider <asn@cryptomilk.org>
The FindPackageHandleStandardArgs module was originally created outside
of CMake. It was added for CMake 2.6.0 by commit e118a627 (add a macro
FIND_PACKAGE_HANDLE_STANDARD_ARGS..., 2007-07-18). However, it also
proliferated into a number of other projects that at the time required
only CMake 2.4 and thus could not depend on CMake to provide the module.
CMake's own find modules started using the module in commit b5f656e0
(use the new FIND_PACKAGE_HANDLE_STANDARD_ARGS in some of the FindXXX
modules..., 2007-07-18).
Then commit d358cf5c (add 2nd, more powerful mode to
find_package_handle_standard_args, 2010-07-29) added a new feature to
the interface of the module that was fully optional and backward
compatible with all existing users of the module. Later commit 5f183caa
(FindZLIB: use the FPHSA version mode, 2010-08-04) and others shortly
thereafter started using the new interface in CMake's own find modules.
This change was also backward compatible because it was only an
implementation detail within each module.
Unforutnately these changes introduced a problem for projects that still
have an old copy of FindPackageHandleStandardArgs in CMAKE_MODULE_PATH.
When any such project uses one of CMake's builtin find modules the line
include(FindPackageHandleStandardArgs)
loads the copy from the project which does not have the new interface!
Then the including find module tries to use the new interface with the
old module and fails.
Whether this breakage can be considered a backward incompatible change
in CMake is debatable. The situation is analagous to copying a standard
library header from one version of a compiler into a project and then
observing problems when the next version of the compiler reports errors
in its other headers that depend on its new version of the original
header. Nevertheless it is a change to CMake that causes problems for
projects that worked with previous versions.
This problem was discovered during the 2.8.3 release candidate cycle.
It is an instance of a more general problem with projects that provide
their own versions of CMake modules when other CMake modules depend on
them. At the time we resolved this instance of the problem with commit
b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake
everywhere, 2010-09-28) for the 2.8.3 release.
In order to address the more general problem we introduced policy
CMP0017 in commit db44848f (Prefer files from CMAKE_ROOT when including
from CMAKE_ROOT, 2010-11-17). That change was followed by commit
ce28737c (Remove usage of CMAKE_CURRENT_LIST_DIR now that we have
CMP0017, 2010-12-20) which reverted the original workaround in favor of
using the policy. However, existing project releases do not set the
policy behavior to NEW and therefore still exhibit the problem.
We introduced in commit a364daf1 (Allow users to specify defaults for
unset policies, 2011-01-03) an option for users to build existing
projects by adding -DCMAKE_POLICY_DEFAULT_CMP0017=NEW to the command
line. Unfortunately this solution still does not allow such projects to
build out of the box, and there is no good way to suggest the use of the
new option.
The only remaining solution to keep existing projects that exhibit this
problem building is to restore the change originally made in commit
b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake
everywhere, 2010-09-28). This also avoids policy CMP0017 warnings for
this particular instance of the problem the policy addresses.
This puts the new search behaviour for included files in action, i.e.
now when a file from Modules/ include()s another file, it also gets the
one from Modules/ included, i.e. the one it expects.
Alex
ZLIB_VERSION_STRING was "1.2.3.#define ZLIB_VERSION "1.2.3"" here, because
the result of the matching for the tweak version was also appended if there
was no TWEAK version and the regexp failed, which gives as result not
an empty string, but the full string.
Now it is only appended if the regexp matches.
Alex
Read zlib.h by using file(STRINGS.....REGEX) to limit the amount of text we apply the version regex on. This patch also addresses the fact that the version string may contain a tweak component.
Patch by Simone Rossetto
Some zlib.h files have ZLIB_VERSION "1.2.3.3" with 4 numbers instead of 3.
The regex is changed to grab the first 3 numbers.
It was slow because if it failed to find that string near the top of the file,
where it usually is, it would read the entire file.
This adds copyright/license notification blocks CMake's find-modules.
Many of the modules had no notices at all. Some had notices referring
to the BSD license already. This commit normalizes existing notices and
adds missing notices.
FIND_PACKAGE_HANDLE_STANDARD_ARGS(), so cmake modules can specify their own
better failure messages. If the default is ok use "DEFAULT_MSG".
Do this also for FindBoost.cmake (#5349)
Alex
