The change in commit v3.11.0-rc1~334^2 (FindOpenMP: Use NO_DEFAULT_PATH
where appropriate, 2017-11-15) broke partial support for Intel on Windows.
Since `OpenMP_${LANG}_IMPLICIT_LINK_DIRS` is empty for this compiler
the `find_library` call without `NO_DEFAULT_PATH` worked accidentally
in environments with the needed libraries in the search path already.
Fix support for Intel on Windows by simply removing our explicit search
for the `libiomp5md` library. In cases that it is needed, the compiler
already inserts metadata in `.obj` files to tell the MSVC linker to use
the library.
Suggested-by: Christian Pfeiffer <cpfeiffer@live.de>
Fixes: #17910
OpenMP libraries must always be found in the implicit linking
directories of a compiler when using the OpenMP compile flag. If a suitable OpenMP library is also found in for example some CMAKE_PREFIX_PATH, this can lead to the module finding the incorrect library.
On the other hand, CMAKE_PREFIX_PATH can't ever be a location that we
need to consider since the OpenMP compile flag would not work if we
needed to.
When invoked in projects that don't set CMP0054 to NEW, FindOpenMP
triggers a warning:
CMake Warning (dev) at .../Modules/FindOpenMP.cmake:... (if):
Policy CMP0054 is not set...Quoted variables like "c" will no
longer be dereferenced when the policy is set to NEW. Since
the policy is not set the OLD behavior will be used.
Set the policy within the module's scope to avoid this.
Fixes: #17292
The overhaul in commit v3.9.0-rc1~207^2~1 (FindOpenMP: Complete
overhaul, 2017-04-24) documented this variable but accidentally left it
unset.
Fixes: #17251
Try `-fopenmp=libiomp5` in addition to `-fopenmp=libomp`. Leave the
latter as the default that we try first when the compiler id is `Clang`.
If that does not work we will still fall back to trying all the
candidates and eventually get to the iomp5 variant.
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names and years are hard to maintain and often out-of-date or plain wrong.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.
Port changes from VTK commit fda6a31cb9 (Added Improved FindOpenMP
module, 2015-04-23). Improve use of try_compile to avoid needing
to pass OpenMP flags as libraries.
Intel Composer XE 2015 Beta 2 deprecates all options starting with -o
for sake of compatibility with other compilers expecting anything goes
after -o... is output file name.
Fixes issues #14812 and #14813 where find_package(OpenMP QUIET) and
find_package(Qt4 QUIET) would still print out messages when calling
check*() functions.
Also a partial fix for #14445 where building CMake
(without cmake-gui) when Qt5 is installed and Qt4 is not installed
and warnings come out of FindQt4.cmake.
This solves a lots of warnings, e.g. in the FindModulesExecuteAll test. If the
installed version on the system is rather old this may even lead to bugs, e.g.
https://bugs.gentoo.org/show_bug.cgi?id=436540
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
Since we know which compiler we have we can test those OpenMP flags first that
are likely to be correct. This doesn't make any difference for GNU compilers,
but it should avoid useless try_compiles and output cluttering for all others.
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
