Recent synopsis changes move from literal code blocks to
[RST line blocks]. This does not translate well to HTML: it's not
rendered in monospace, so aligment is lost. Additionally, we don't
get syntax highlighting in HTML, which adds differences to our code
samples which are highlighted.
We hard-wrap synopsis lines (like code blocks). To align continuation
lines in manpages we need [backslashes in weird places]. Combined with
the **, *, and `` markup, it's a bit hard to get the alignment right.
Fix these by moving synopsis sources back to code blocks and compute
HTML syntax highlighting and manpage markup with a custom Sphinx
extension.
The new Pygments lexer can tokenize a synopsis and assign the various
highlighting roles, which closely matches fish's syntax highlighing:
- command/keyword (dark blue)
- parameter (light blue)
- operator like and/or/not/&&/|| (cyan)
- grammar metacharacter (black)
For manpage output, we don't project the fish syntax highlighting
but follow the markup convention in GNU's man(1):
bold text type exactly as shown.
italic text replace with appropriate argument.
To make it easy to separate these two automatically, formalize that
(italic) placeholders must be uppercase; while all lowercase text is
interpreted literally (so rendered bold).
This makes manpages more consistent, see string-join(1) and and(1).
Implementation notes:
Since we want manpage formatting but Sphinx's Pygments highlighing
plugin does not support manpage output, add our custom "synopsis"
directive. This directive parses differently when manpage output is
specified. This means that the HTML and manpage build processes must
not share a cache, because the parsed doctrees are cached. Work around
this by using separate cache locations for build targets "sphinx-docs"
(which creates HTML) and "sphinx-manpages". A better solution would
be to only override Sphinx's ManualPageBuilder but that would take a
bit more code (ideally we could override ManualPageWriter but Sphinx
4.3.2 doesn't really support that).
---
Alternative solution: stick with line blocks but use roles like
:command: or :option: (or custom ones). While this would make it
possible to produce HTML that is consistent with code blocks (by adding
a bit of CSS), the source would look uglier and is harder to maintain.
(Let's say we want to add custom formatting to the [|] metacharacters
in HTML. This is much easier with the proposed patch.)
---
[RST line blocks]: https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#line-blocks
[backslashes in weird places]: https://github.com/fish-shell/fish-shell/pull/8626#discussion_r782837750
sphinx-build supports the -j option to use multiple processes. Start using
it. This reduces the time to build the docs on my Linux box from 11 seconds
to about 4.
Note this doesn't work on macOS since -j is ignored there (see sphinx-build
PR 6879).
This fixes a variety of issues related to building the documentation
with CMake. In particular it cleans up the dependency management and
fixes some issues where the documentation build was using generated
files from the source directory.
This untangles the CMake versioning issues (I hope) as discussed in #4626.
Note most of the advice found on the Internet about how to inject git
versions into CMake is just wrong.
The behavior we want is to unconditionally run the script
build_tools/git_version_gen.sh at build time (i.e. when you invoke ninja or
make, and not when you invoke cmake, which is build system generation time).
This script is careful to only update the FISH-BUILD-VERSION-FILE if the
contents have changed, to avoid spurious rebuilding dependencies of
FISH-BUILD-VERSION-FILE. Assuming the git version hasn't changed, the script
will run, but not update FISH-BUILD-VERSION-FILE, and therefore
fish_version.o will not have to be rebuilt.
This might normally rebuild more than is necessary even if the timestamp is
not updated, because ninja computes the dependency chain ahead of time. But
Ninja also supports the 'restat' option for just this case, and CMake is rad
and exposes this via BYPRODUCTS. So mark FISH-BUILD-VERSION-FILE as a
byproduct and make the script always update a dummy file
(fish-build-version-witness.txt). Note this is the use case for which
BYPRODUCTS is designed.
We also have fish_version.cpp #include "FISH-BUILD-VERSION-FILE", and do a
semi-silly thing and make FISH-BUILD-VERSION-FILE valid C++ (so there's just
one version file). This means we have to filter out the quotes in other
cases..
