Propagates variables set in enable_language() logic up variable scopes
so that the language can be used by targets in the ancestor directories.
Works through block() and function() scopes as well. The
add_subdirectory() call can be thought of as the effective call site for
enabling the language. The same holds for endblock() and the actual
function call.
Adds a policy CMP0220 to control this behavior. As the language is
"enabled" at each ancestor scope, the policy is checked. If OLD, the
language is not enabled at this scope and the ones above.
Closes: #27881#27508#27389
Related: #26751#27564
In commit b787be2714 (Help: Update supported languages in project and
enable_language, 2023-01-20, v3.26.0-rc1~53^2) the relevant paragraph
was accidentally moved to the `enable_language` command documentation.
Fixes: #25016
This change ony concerns directives that appear in the document body.
The guidelines for inserting version directives:
* Baseline version is CMake 3.0, i.e. directives start at 3.1.
* Always use `.. versionadded::` directive, avoid ad-hoc version
references. Exception: policy pages.
* For new command signatures, put `versionadded` on a separate line
after the signature.
* For a group of new signatures in a new document section,
a single version note at the beginning of the section is sufficient.
* For new options, put `versionadded` on a separate line before
option description.
* If all the option descriptions in the list are short one-liners,
it's fine to put `versionadded` on the same line as the description.
* If multiple option descriptions in close proximity would have
the same ..versionadded directive, consider adding a single
directive after the list, mentioning all added options.
* For compact value lists and sub-option lists, put a single
`versionadded` directive after the list mentioning all additions.
* When a change is described in a single paragraph, put
`versionadded` into that paragraph.
* When only part of the paragraph has changed, separate the changed
part if it doesn't break the flow. Otherwise, write a follow-up
clarification paragraph and apply version directive to that.
* When multiple version directives are close by, order earlier
additions before later additions.
* Indent related lists and code blocks to include them in the scope
of `versionadded` directive.
Issue: #19715
Add entries in Modules and Modules/Platform to support
Objective-C++ compiler determination and identification.
Add Modules to check Objective-C++ compiler flags, source
compilations, program checks, etc...
Use OBJCXX as the designator of the language, eg:
project(foo OBJCXX)
Add various tests for Objective-C++ language features. Add
tests to preserve C++ handling of .M and .mm files when
Objective-C++ is not a configured language.
Co-authored-by: Cristian Adam <cristian.adam@gmail.com>
Add entries in Modules and Modules/Platform to support
Objective-C compiler determination and identification.
Add Modules to check Objective-C compiler flags, source
compilations, program checks, etc...
Use OBJC as the designator of the language, eg:
project(foo OBJC)
Add various tests for Objective-C language features. Add
tests to preserve C++ handling of .m and .mm files when
OBJC is not a configured language.
Co-Authored-By: Cristian Adam <cristian.adam@gmail.com>