Add bare minimum functionality to compile C code and link on Windows.
Explicitly label tests that are expected to work with `CFLAGS=-Ze`.
Leave out documentation for now because this is not usable in general.
Issue: #21536
Inspired-by: Serguei E. Leontiev <leo@sai.msu.ru>
Since commit 4a4986d28a (cxxmodules: support command templates for BMI
compilation, 2026-03-25, v4.3.1~2^2~1) we can express module interface
unit compilation to either object files or BMI-only in a way that works
with `clang-scan-deps` and `clang-cl` together.
Fixes: #25731
7ebb5687ab cmGeneratorTarget: use typename for `flag`
4a4986d28a cxxmodules: support command templates for BMI compilation
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !11871
Some compilers (Clang) warn when using their BMI-only flag with `-c`.
Support a complete template for BMI compilation rather than an
additional flag to support such toolchains.
Fixes: #27600
Before it would result in us writing the unescaped backslashes to
`CMakeCXXCompiler.cmake` resulting in invalid escape characters causing
the configure to error out.
Several problems with this feature came up while testing 4.3.0-rc1.
These include both broken stdlib distributions and regressions in our
implementation of the feature since CMake 4.2.
Revert commit 70c1f0f43d (Experimental: Remove import std experimental
gate, 2026-02-04, v4.3.0-rc1~61^2) except for its incidental fixes.
Remove the 4.3 release notes related to `import std`.
Rotate the experimental gate's UUID.
Issue: #27426
Issue: #27597
Issue: #27626
Issue: #27635
And change checks to look for a value rather than definition. This fix
keeps the same set of test cases in `RunCMake.CXXModules` selected as
before.
Fixes: #27589
Previously, `CMAKE_<LANG>_LINK_FLAGS` was an undocumented variable used
for linking executables only. Re-spell that variable mirroring the
existing spellings for shared and module libraries, and add policy
CMP0210 to preserve compatibility.
Then, repurpose `CMAKE_<LANG>_LINK_FLAGS` to provide a variable to be
used for per-language link flags for all target types, along with a
per-configuration variant. These are added to the `<LINK_FLAGS>` rule
placeholder in the generators.
Fixes: #21934
Relates: #25620
Co-authored-by: Brad King <brad.king@kitware.com>
In flang, both -J and -module-dir support both joined and separate values. For
the -J option, these are of the form `-J<value>` and `-J <value>` respectively.
Once https://github.com/llvm/llvm-project/pull/168748 is committed, -module-dir
will only work with a separate value. Setting CMAKE_Fortran_MODDIR_FLAG to -J
ensures that both joined and separate styles will continue to work after that
change is made. As far as behavior is concerned, both -J and -module-dir are
aliases.
Adds a parser and serializer for the EcoStd Module Metadata format
RFC: https://github.com/ecostd/rfcs/pull/3
This adapts the existing experimental support for import std; to use
the new parser. The CMAKE_CXX_STDLIB_MODULES_JSON is now the canonical
variable for controlling how CMake discovers the stdlib module metadata,
and is used directly by compiler detection.
Toolchains can still override the __CMAKE::CXX## targets if they wish,
either in conjunction with CMAKE_CXX_STDLIB_MODULE_JSON or not. It is
possible to disable automatic detection of
CMAKE_CXX_STDLIB_MODULE_JSON by setting it to the empty string.
When available, the CMAKE_CXX_STDLIB_MODULE_JSON will be used to create
all requested C++ stdlibs which do not already have targets.
Some deployments may not be able to discover the metadata file reliably
(e.g., custom `clang` builds on macOS while using the SDK's stdlib or
distribution bugs). Allow users to force the location so that
compiler-driven detection doesn't have to bend over backwards for
unforeseen bugs.
Although there is no `cl -std:c23` flag, the underlying Clang compiler
does have a C23 mode we can activate by passing `-std=c23` through a
`clang-cl` wrapper flag.
Also port the fix from commit 30139913e9 (VS: Restore support for mixing
C++23 and C in one target with clang-cl, 2024-12-09, v3.31.3~10^2).
Fixes: #27038
Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Co-authored-by: Brad King <brad.king@kitware.com>
d592558b8b cmLocalGenerator: Drop no-op link flag placeholder infrastructure
67639002ad Ninja,Makefile: Drop now-unused placeholders from link rule variables
951e4d3f62 Ninja,Makefile: Move builtin linker flags to <LINK_FLAGS> placeholder
6b618c6079 cmLocalGenerator: Clarify MODULE link flags placeholder population
c52a654aa1 cmLocalGenerator: Improve formatting of rule placeholder variable list
37cf9941ed UseEcos: Add missing placeholder in rules to link executables
fa61be5bc4 Embarcadero,OpenWatcom: Clear unused flags for creating shared libraries
124e40947c CMakeCommonLanguageInclude: Do not unset MODULE library flags when empty
...
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !10869
Previously we used separate placeholders for builtin linker flags:
* CMAKE_<LANG>_LINK_FLAGS for EXECUTABLEs
* CMAKE_SHARED_LIBRARY_CREATE_<LANG>_FLAGS for SHARED libraries
* CMAKE_SHARED_MODULE_CREATE_<LANG>_FLAGS for MODULE libraries
These are now always replaced by the empty string, so drop them
from our rule variables.
Clear `CMAKE_SHARED_LIBRARY_CREATE_<LANG>_FLAGS` since no special
link flags are needed to create a DLL with these toolchains.
Our shared library creation rules do not reference the placeholder,
so this variable was never used. However, we may soon teach the
generators to look it up directly.
This was done by mistake in commit d090159318 (ENH: add support for the
ADSP toolchains for Blackfin, Shark and TigerShark DSPs, patch from
Raphael Cotty, 2007-07-12, v2.6.0~1446), and preserved in the
generalization by commit e9eabb0dcd (ADSP: Configure compiler in
compiler module, 2022-03-24, v3.24.0-rc1~331^2~1). Fix both places.
In commit c54a621b55 (Cray: New platform file for Cray Linux Environment
and PrgEnv, 2015-11-13, v3.5.0-rc1~216^2~1) we populated variable
`CMAKE_STATIC_LIBRARY_LINK_<LANG>_FLAGS`, but we never reference it, and
the generators do not use it. Static libraries are archives, and are
not produced by a linker.
In commit 9e66397c28 (Languages: Add support for Objective-C++,
2019-09-13, v3.16.0-rc1~44^2~2) we set `CMAKE_OBCXX_LINK_FLAGS`.
It was a typo for `CMAKE_OBJCXX_LINK_FLAGS`, and so has not had
any effect.
LLVM/Clang 20, when invoked as `clang++ -E -c ...`, now warns:
warning: argument unused during compilation: '-c'
Drop the unnecessary `-c` flag. Also add a `-w` flag to suppress
warnings so their text is not parsed as predefines.
Pass `-g` to enable debugging, not `-O` for optimizations. This was
probably a typo in commit b50bfc8913 (HIP: Add language to CMake,
2020-08-28, v3.21.0-rc1~66^2~4).
Fixes: #26823
