If a single-value keyword is followed by an empty string, the
command unsets the variable for that keyword instead of setting
it to the empty string. This is inconsistent and unexpected. Add
policy CMP0174 which ensures the variable for a single-value
keyword is always set when any value is given, not just for a
non-empty value.
The new CMP0174 policy only affects the PARSE_ARGV form of
cmake_parse_arguments. The older form silently drops all empty
string arguments before processing the argument list.
Fixes: #25972
`.. versionchanged` directive might be more appropriate when
documentation refers to previous CMake version, old behavior
or a policy, and there's no new parameter or a variable involved.
Issue: #19715
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
Revise docs for all "Scripting Commands", except four find_XXX
that use a macro suite of their own.
* Take full advantage of the improved syntax highlighting.
* Make consequential use of <..> placeholders.
* Clarify things here and there in the text.
Specific improvements to some command docs:
* "math": Correct description of novel hexadecimal capability.
* "if", "foreach", "while": Provide link to "endif" etc
* "foreach", "while": Mention "break" and "continue".
* "foreach": Simplify explanation of ``RANGE`` and ``IN`` signatures;
advise against negative arguments or reverse ranges (compare issue #18461)
* "endif", "endfunction" etc: Explain that the argument is optional and
maintained for compatibility only
The `ARGC`/`ARGV#` variables in function scope hold the original
arguments with no ;-list flattening. Add a way for functions to
cleanly parse arguments that may contain `;`. This also avoids
extra copying of the arguments.
Co-Author: Brad King <brad.king@kitware.com>
The behaviour of double specified keywords is rather undefined or at
least not clearly documented. This change introduces a strict check and
emits a warning in case a keyword has been specified more than once.
Implement a native `cmake_parse_arguments` command that is fully
compatible with the documented behaviour of the previous implementation.
Leave the CMakeParseArguments module empty but existing for
compatibility.
