Windows is heading toward making UTF-8 the preferred MBCS. As CMake's
internal encoding, `UTF-8` is effectively equivalent to `NONE`, which
was CMake's behavior prior to 3.15's accidental change to `AUTO`.
Behavior of `ENCODING UTF-8` is independent of CMake's internal
encoding, making it in principle a better default than `NONE`.
Add policy CMP0176 for compatibility and to document the default's
history.
Fixes: #26262
The default was originally AUTO in commit 2ed473b3b8 (execute_process:
Add ENCODING option for Windows child process output, 2016-11-23,
v3.8.0-rc1~232^2) but was changed back to NONE by commit 07c3380a6e
(execute_process: Restore no-decoding default behavior, 2017-02-13,
v3.8.0-rc2~26^2) for CMake 3.8. Later it was accidentally changed back
to AUTO by commit b783e62533 (cmExecuteProcessCommand: Port to
cmArgumentParser, 2019-03-25, v3.15.0-rc1~270^2) in CMake 3.15 but the
documentation was not updated. Document the current default, AUTO, and
add a test case to verify it.
Issue: #26262
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 COMMAND_ECHO option to the execute_process command. This will allow
execute_process to show the command it will run. Also add a cmake variable
CMAKE_EXECUTE_PROCESS_COMMAND_ECHO. Both the option and the variable can
be set to one of the following: STDERR|STDOUT|NONE. The command will be
printed to stderr or stdout or not at all.
Fixes: #18933
When reading the doc page on execute_process, I was mislead by the
words "in parallel". They convinced at once that the processes
are run independently of each other, so that I did not even bother
to read further. The rewording, and not least the insertion of a
paragraph break, should prevent such oversight.
* The code snippets in the docs consist of CMake code mixed
with syntax definition punctuation like < > [ ] ... Therefore
a pure CMake lexer is inadequate. Here it is replaced by a
CMake syntax definition parser.
* Fixed syntax definition snippets in FindPkgConfig.cmake to
make best use of syntax highlighting. This source file is the
hardest to support because it contains comparison operators
<= = >=, which need special attention to avoid confusion
with the placeholder indicators <...>.
* Fixed syntax in execute_process.rst (there were unbalanced
brackets).
* Disabled syntax highlighting for long string examples in
cmake-language.7.rst.
* No highlighting of removed syntax in CMP0049
* To inspect the outcome of this patch, see e.g. the pages
* manual/cmake-buildsystem.7.html
* module/ExternalProject.html
* module/FindPkgConfig.html
which are particularly rich in complex code snippets.
UTF-8 is the proper naming according to the UTF-8 RFC and is also the
name used for a similar keyword in the file() command. This commit
brings (backward compatible) consistency to the keyword names and allows
the standard UTF-8 name to be used with execute_process(). The old UTF8
keyword is still supported.
Since commit v3.8.0-rc1~232^2 (execute_process: Add ENCODING option for
Windows child process output, 2016-11-23) we decode child process output
using the console's active codepage by default. This differs from
previous versions of CMake and is therefore incompatible. Changing this
default will require a policy, so for now revert the default behavior
back to performing no decoding.
Reported-by: Nils Gladitz <nilsgladitz@gmail.com>
The execute_process command starts all commands in parallel (in order
for the piping to work). Mention this explicitly and also add a note
about how to execute commands sequentially.
Use the KWSys Process "MergeOutput" option to give the child process
the same pipe (or file) for both stdout and stderr. This allows
natural merging of stdout and stderr together instead of merging
on arbitrary buffered read boundaries as before.
State in the execute_process how COMMAND arguments are passed to
the child. Add a note at the end about how the command differs
from add_custom_*().
Suggested-by: Alan W. Irwin
