AUTOMOC used to fail to generate ``moc_predefs.h`` when ``ccache`` was used
as a compiler starter by e.g. configuring a project with the environment
variable CXX="ccache g++".
The reason was that ``CMAKE_<LANG>_COMPILER_ARG1`` wasn't respected in the
definition of ``CMAKE_<LANG>_COMPILER_PREDEFINES_COMMAND`` for various
compilers. This is fixed by this patch.
Fixes#17275.
In commit v3.12.0-rc1~20^2 (Move GNU COMPILER_PREDEFINES_COMMAND from
Platform to Compiler, 2018-06-01), `Compiler/GNU.cmake` introduced the
`-dM` flag, which requires `-Wp` prefix for the QNX compiler wrapper.
We only define `INTERPROCEDURAL_OPTIMIZATION` behavior for C, CXX, and
Fortran languages. Do not try to enable support for other languages.
Furthermore, each language builds with a different compiler, so check
for support by CMake and the compiler for each language independently.
Fixes: #16944
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names and years are hard to maintain and often out-of-date or plain wrong.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.
When system-provided packages are upgraded we must re-compile sources
depending on their headers. Use `-MD` instead of `-MMD` so that the
generated depfiles do not exclude system headers.
Suggested-by: Jussi Judin
Commit v3.0.0-rc1~111^2 (QNX: Introduce QCC compiler id for that
QNX platform compiler., 2014-01-20) split handling of the QNX QCC
compiler into a separate compiler-id. That refactoring results in
the QCC compiler not using the CMake-compiler-id "GNU", which means
that the __compiler_gnu macro is no longer executed for it.
Add Compiler/QCC*.cmake modules to define and call the __compiler_qcc
macro and teach it to call __compiler_gnu internally. Remove the
corresponding pieces from the Platform/QNX*.cmake modules.
It is also necessary to change the language conditional to dereference
the lang macro parameter, which is another bug introduced by the
same commit. The extra -lang-c++ flag is only necessary when the CXX
compiler is specified as 'qcc' instead of 'QCC' in the toolchain file,
which is why this bug was not noticed before. The flag is also necessary
in that case when linking in order to find the appropriate standard
libraries. The flag was not previously added when linking executables,
so linking failed even with CMake 2.8.12 with the lower-case compiler-id.
Co-Author: Brad King <brad.king@kitware.com>
