Don't initialize the other CMAKE_<LANG>_COMPILER_PREDEFINES_COMMAND
variables.
The only language variant that is used is
CMAKE_CXX_COMPILER_PREDEFINES_COMMAND, and the other language variants
contained invalid, namely C++-specific commands.
Fixes: #23968
These changes are in preparation of compiler generated dependencies support
for Makefiles generators
* compiler output and dependency target can be different for Makefiles generators
* resolve inconsistency naming for dependency file place-holder
QCC is a wrapper around GCC, but it is not a fully transparent wrapper.
Some compile options need to be passed to GCC using a `-Wc` option.
QCC does not support --sysroot, so setting CMAKE_SYSROOT in a toolchain
file currently does not work. This means that it is likely that no one
is setting CMAKE_SYSROOT in existing QNC toolchain files. Override the
GCC option for sysroot in the QCC.cmake file with -Wc,-isysroot.
This exposes a further issue in that the QNX SDK does not follow the
same architectural folder structure as linux uses. That is, on linux
systems, architecture-specific libraries might be in
<sysroot>/usr/lib/<arch>
such as
/usr/lib/x86_64-linux-gnu/libcurl.so
CMake models this by suffixing the <arch> onto lib directories when
searching for libraries.
The QNX SDK is structured differently such that the <arch> should be
used as a prefix:
<sysroot>/<arch>/usr/lib
such as
<sysroot>/x86_64/usr/lib/libcurl.so
Add a variable for platform configuration to set whether to prefix or
suffix the <arch> and set that in the QCC.cmake.
Use the directory structure of the QNX SDK to compute the <arch> from
the implicit library directories. The assumption is that the arch will
be a single directory directly below the CMAKE_SYSROOT, below which the
usr/ prefix occurs.
It would not be appropriate to instruct users to make the <arch> part of
the sysroot when specified in the toolchain file because:
1. That would be non-DRY - The QCC wrapper already determines the <arch>
by the -V argument passed to the compiler, specified in the toolchain
file as the CMAKE_C_COMPILER_TARGET variable.
2. The includes in the QNX SDK are not below the <arch> directory.
So, the location of the <arch> in the full path is different on QNX
compared to, say an embedded linux platform, but the intent is the same.
Add documentation to recommend the use of CMAKE_SYSROOT in a QNX
toolchain file.
As the CMAKE_SYSROOT is always the same for QNX, it would be possible to
simply set it in QCC.cmake. However, that would change behavior for
existing users as when CMAKE_SYSROOT is set, files/paths outside of the
CMAKE_SYSROOT do not get found.
The <arch> prefixing is only enabled in cmSearchPath.cxx if
CMAKE_SYSROOT is set. This ensures that the user gets consistency in
the current state without CMAKE_SYSROOT, and gets better consistency
when using CMAKE_SYSROOT.
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>
