Divert LCC compiler as a new one, instead of treating it as GNU.
Since old times, Elbrus C/C++/Fortran Compiler (LCC) by MCST has been
passing checks for GNU compilers, so it has been identified as GNU.
Now, with intent of seriously upstreaming its support, it has been
added as a separate LCC compiler, and its version displays not a
supported GCC version, but LCC version itself (e.g. LCC 1.25.19 instead
of GNU 7.3.0).
This commit adds its support for detection, and also converts basically
every check like 'is this compiler GNU?' to 'is this compiler GNU or
LCC?'. The only places where this check is untouched, is where it
regards other platforms where LCC is unavailable (primarily non-Linux),
and where it REALLY differs from GNU compiler.
Note: this transition may break software that are already ported to
Elbrus, but hardly relies that LCC will be detected as GNU; still such
software is not known.
The pch object file could cause problems when the reused pch is passed
through an OBJECT library, which would use INTERFACE_LINK_LIBRARIES to
link the pch object file.
Fixes: #22630
Fix logic from commit 9df1f33c9a (VisualStudio: move PCH rules to
projects when possible., 2020-10-15, v3.20.0-rc1~638^2) to explicitly
disable PCH on sources that should not use the target-wide PCH rules.
Fixes: #21827
Update the test added by commit 8c8f03422e (PCH: Template instantiation
support, 2020-08-28) to recognize flags on PCH files whose names include
the architecture. This occurs when `CMAKE_OSX_ARCHITECTURES` is set.
Adds PCH_INSTANTIATE_TEMPLATES target property for enabling template
instantiation in precompiled headers.
Enabled by default. Currently only supported for Clang 11 and newer.
Implements #21133.
Since commit 729d997f10 (Precompile Headers: Add REUSE_FROM signature,
2019-08-30, v3.16.0-rc1~101^2), `GetPchFileObject` handles the case that
it is called first for another target's `REUSE_FROM` by calling
`AddSource` to make sure `GetObjectName` can produce the correct object
name. However, `AddSource` causes `ClearSourcesCache` to be called,
which since commit a9f4f58f0c (cmGeneratorTarget: Clear AllConfigSources
in ClearSourcesCache, 2020-05-15, v3.16.7~2^2) now correctly erases the
`AllConfigSources` structure. This is okay during `AddPchDependencies`,
but there is another code path in which it is problematic.
When the Visual Studio generator's `WriteAllSources` method is looping
over the sources, the `cmake_pch.cxx` source is encountered first. This
causes `OutputSourceSpecificFlags` to call `GetPchCreateCompileOptions`,
which calls `GetPchFile`, which under MSVC with `CMAKE_LINK_PCH` calls
`GetPchFileObject`. That leads to `ClearSourcesCache` erasing the
structure over which `WriteAllSources` is iterating!
This bug is caught by our `RunCMake.PrecompileHeaders` test when run
with the VS generator as of the commit that exposed it by fixing
`ClearSourcesCache`. However, that change was backported to the CMake
3.16 series after testing only with later versions versions that contain
commit a55df20499 (Multi-Ninja: Add precompile headers support,
2020-01-10, v3.17.0-rc1~136^2). By adding proper multi-config support
for PCH, that commit taught `cmLocalGenerator::AddPchDependencies` to
call `GetPchFile` with the real set of configurations instead of just
the empty string. This allows the `GetPchFile` cache of PCH sources to
be populated up front so that the later calls to it in the
`WriteAllSources` loop as described above do not actually call
`GetPchFileObject` or `ClearSourcesCache`. That hid the problem.
Fix this by re-ordering calls to `AddPchDependencies` to handle
`REUSE_FROM` targets only after the targets whose PCH they re-use.
Remove the now-unnecessary call to `AddSource` from `GetPchFileObject`
so that `ClearSourcesCache` is never called during `WriteAllSources`.
Update the PchReuseFrom test case to cover an ordering of targets that
causes generators to encounter a `REUSE_FROM` target before the target
whose PCH it re-uses.
Fixes: #20770
Some RunCMake tests fail with this warning due to extra stderr content:
warning: this old-style function definition is not preceded by a prototype
Convert `foo()` to `foo(void)` in `.c` sources of affected tests.
When the path to a header file is specified using a generator
expression, evaluation of the genex must produce an absolute path.
Update our documented example and add a test covering the case.
Fixes: #20617
If the target has C files, it will get a C PCH file.
The same for C++ files. The linker language is no
longer used to determine which language to use for
PCH.
Fixes: #19790
makise-homura