Introduce a mechanism (via the private and undocumented `ISSUE_WARNING`
option to the `cmake_policy` command) to allow built-in modules to issue
policy warnings. Update modules to use this.
This allows modules to issue policy warnings with the `CMD_POLICY`
diagnostic type, which is consistent with internally issued diagnostics.
This also tends to simplify the logic for issuing such warnings in much
the way the helpers introduced in the previous commit did for the C++
code.
Update expected test output to account for the new format of diagnostic
messages. These changes were applied entirely by `sed` using the
following commands:
- `/Use -Wno-dev to suppress/s/-Wno-dev/-Wno-author/g`
- `s/Warning [\\][(]dev[\\][)]/Warning \\(author\\)/g`
- `s/CMake Deprecation Warning/CMake Warning \\(deprecated\\)/g`
This is not a complete fix, but covers a significant fraction of the
needed changes, and this commit is strictly automated changes.
Since commit 6baf65ec46 (ASM: Do not consider MSVC C/CXX compiler for
generic ASM, 2025-04-08) we no longer mistake `cl` for an assembler.
However, some projects unconditionally enable ``ASM``, which worked
on Windows only due to that bug. Restore compatibility with such
projects by guarding the change behind a new policy ``CMP0194``.
Fixes: #26907
Issue: #26617
Jocó Mihalicza
Matthew Woehlke
AJIOB
Hanna Rusakovich
Brad King