Follow the approach from commit 92320466dd (try_compile: Restore
platform-default link flags in pre-CMP0210 projects, 2026-08-22)
to make the CMP0181 policy setting available in `try_compile`
projects before the toolchain file is loaded.
Fixes: #28108
The CMP0210 compatibility shims in the Darwin, AIX, HP-UX and ARMClang
modules read the policy with cmake_policy(GET CMP0210 ...) during
enable_language(), which runs inside project(). cmCoreTryCompile emitted
cmake_policy(SET CMP0210 ...) after project() in the generated test
project, so those shims always observed NEW regardless of the calling
project's setting.
On affected platforms this dropped the platform default link flags from
every try_compile, and left a toolchain-file value of
CMAKE_<LANG>_LINK_FLAGS unclobbered so that it reached the OLD code path.
For projects that are also not using CMP0181 NEW, that path uses the
variable as is and does not expand the LINKER: prefix.
Move the emission into the existing pre-project() policy block alongside
CMP0126, CMP0128 and CMP0197, which exist for exactly this reason.
Fixes: #28102
Move some target related enumeration types from `cmStateTypes.h` to a
new header, as these really aren't "state" types. Also, make
`TargetType` a strongly-typed enumeration.
Do not honor `CMAKE_EXE_LINKER_FLAGS` in `try_compile` unless the outer
project sets CMP0214 to NEW. This bug in commit 15a6d96359 (Swift:
Honor CMAKE_EXE_LINKER_FLAGS when CMP0157 is NEW, 2026-04-15) was
exposed by commit f2641bcbef (Begin 4.4 release versioning, 2026-06-04).
Issue: #26154
Add and use a couple helper functions for issuing policy warnings. This
improves consistency and allows some simplification of many call sites.
(One or two instances in particular are greatly simplified.)
Add new diagnostic categories CMD_POLICY and CMD_EXPERIMENTAL, both as
children of CMD_AUTHOR. Use the former when issuing policy warnings. Use
the latter when issuing experimental feature warnings.
Find places that are currently relying on diagnostic-specific message
types to issue diagnostics and replace these with calls to the new
diagnostic methods.
Do not propagate deprecated diagnostic variables to try_compile.
Instead, if any diagnostic is ignored in the calling instance, also
ignore it in the try_compile instance.
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>
Since commit 96d9b94a98 (Emscripten: Add platform modules, 2025-05-16,
v4.2.0-rc1~607^2~3) we've considered the `.wasm` to be the `try_compile`
output because we need `COPY_FILE` to get it for extracting `INFO:`
strings during our inspection checks. This breaks `try_run` because
`node`, used via `CMAKE_CROSSCOMPILING_EMULATOR`, expects the `.js`.
Revert to considering the `.js` to be the primary output file, but
switch to the `.wasm` in `COPY_FILE`'s implementation.
Fixes: #27421
`include-what-you-use` diagnostics, in practice, are specific to
the environment's compiler and standard library. Update includes
to satisfy IWYU for our CI job under Debian 13. Some patterns:
* Types named in virtual `override` signatures no longer require
includes since the overridden signature already names them.
* A function argument's type needs to be included even if its constructor
is called only by implicit conversion. For example, constructing a
`std::function` from a lambda now requires `<functional>`.
* Some prior mysterious `<type_traits>` inclusions are no longer required.
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.
The `CMAKE_{EXE,SHARED,MODULE,STATIC}_LINKER_FLAGS` variables are
not language-specific, so multiple languages' toolchains may disagree
about if/how to pass the flag through a compiler driver to the linker.
Furthermore, carrying the flag in public-facing variables allows projects
or users to change it even though it is required. Add policy CMP0197
to remove the flag from the public-facing variables and generate it
automatically instead:
* For command-line generators, add the `-machine:` flag to the
linker and archiver rule variables.
* For Visual Studio generators, we do not need to explicitly add the
link `-machine:` flag. MSBuild automatically adds it, and the new
behavior actually removes a duplicate we generated previously.
Issue: #21934
Refactoring in commit c4e890946a (try_compile: consistently add language
properties, 2020-06-15, v3.19.0-rc1~633^2) accidentally dropped the
`_LINK` part of the name. It also miscounted array indexes in a way
that happened to propagate `CMAKE_<LANG>_LINK_NO_PIE_SUPPORTED` whether
or not it is needed for the CMP0083 NEW behavior. Simplify the code and
fix the variable name.
Fixes: #26948
Replace our hard-coded default for `/RTC1` with a first-class
abstraction to select runtime checks from an enumeration of logical
names. Add a `MSVC_RUNTIME_CHECKS` target property and corresponding
`CMAKE_MSVC_RUNTIME_CHECKS` variable.
Removing the old default flag requires a policy because existing
projects may rely on string processing to edit them and choose
runtime checks under the old behavior. Add policy CMP0184 to
provide compatibility.
Fixes: #26614
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`, now with "east const" enforcement.
Use `clang-format` version 18.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Issue: #26123
When profiling Qt builds on macos, about 2.2% of a `cmake` invocation
was spent reading from `/dev/urandom`. Use a (thread)local rng to
mitigate this cost, particularly in `cmGeneratedFileStreamBase::Open`.
This indicates to MSBuild which configurations are considered debug
configurations. This is useful for reference both by humans and tools.
Issue: #25327
a820877d03 errors: avoid constructing a stream before getting the last error
5cf7018af6 cmFileCopier: remember error statuses and get their strings
0639a32d3a cmFileTimes: return status codes from APIs
Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !9023
Add a `CMAKE_Swift_COMPILATION_MODE` variable and corresponding
`Swift_COMPILATION_MODE` target property to control the compilation
mode. Select among `wholemodule`, `singlefile`, and `incremental`.
Add policy CMP0157 to remove the default `-wmo` flags in favor of the
abstract setting.
Issue: #25366
Offer the capability, through variable `CMAKE_LINKER_TYPE`, as well as
the target property `LINKER_TYPE` to specify which linker must be used.
The implementation of this capability is specified by variables specific
to the language and linker type: `CMAKE_<LANG>_USING_LINKER_<TYPE>`.
Some definitions are provided as part of `CMake`.
For example, to select the `LLVM` linker rather than the standard one,
the type `LLD` should be specified through the variable `CMAKE_LINKER_TYPE`.
And, on `Apple`, `Linux` and some environments on `Windows`, the variable
`CMAKE_<LANG>_USING_LINKER_LLD` has value `-fuse-ld=lld`. And for `Windows`
environments based on `MSVC`, where the linker is used directly, the tool
`lld-link.exe` will be used rather than `link.exe`.
Fixes: #19174, #24254, #24990
Under CMP0155's NEW behavior, projects that explicitly enable C++20
support with `set(CMAKE_CXX_STANDARD 20)` may also explicitly
disable scanning with `set(CMAKE_CXX_SCAN_FOR_MODULES OFF)`.
We already propagate `CMAKE_CXX_STANDARD` into `try_compile` test
projects, so propagate `CMAKE_CXX_SCAN_FOR_MODULES` too.
Fixes: #25313
Following commit 6377a43814 (CUDA: Support response files with nvcc,
2022-06-01, v3.25.0-rc1~636^2), while determining the compiler ABI, do
not use response files, so that we can extract implicit link flags.
Fixes: #25272
Brad King
AJIOB
Mickaël Germain
Matthew Woehlke
Daniel Pfeifer
John Franklin Rickard
Tyler YankeeandBrad King
Ben Boeckel
Quinn Powell
Kitware Robot
Tim Blechmann
Marc Chevrier
Craig Scott
Evan Wilde
Cristian Le
scivision