tree: 631d0c91e4758e1160191a656c7ff0de541357da [path history] [tgz]
  1. Debugger/
  2. JITOptimizations/
  4. SavedFrame/
  6. lib/

SpiderMonkey in-tree documentation

This directory contains documentation for selected parts of SpiderMonkey. The docs are published on the Mozilla Developer Network, but this is the authoritative copy; the MDN pages are updated from these files by a script. At the moment, we have:

  • js/src/doc/Debugger, SpiderMonkey's JavaScript debugging API, commonly known as Debugger.

  • js/src/doc/SavedFrame, SpiderMonkey's compact representation for captured call stacks.

and that's it.

To format the documentation, you'll need to install Pandoc, a documentation format conversion program. Pandoc can convert Markdown text, which is pleasant to read and write, into HTML, which is what MDN expects.

Management scripts

There are two scripts you may want to use while working with js/src/doc subdirectories:

  • [--mdn] SOURCEDIR OUTPUTDIR produces HTML from the document sources in SOURCEDIR, placing the results in OUTPUTDIR. You can then check their appearance with a web browser.

    Normally, arranges the links and HTML metadata so that the pages view correctly when visited at file:// URLS pointing into OUTPUTDIR. However, pages published to MDN should not have the HTML metadata that stand-alone pages need, and their relative positions may be different; passing the --mdn switch tells to produce output for publication to MDN, not for previewing on disk.

    (Why are the links affected by --mdn? The MDN wiki allows you to create a page named .../foo, and then create sub-pages named .../foo/bar. This is a nice way to arrange, say, a summary page and then sub-pages providing details. But it‘s impossible to create the parallel structure on a POSIX file system: .../foo can’t be both a file and a directory, so the links that would be correct when published on the wiki cannot be correct when previewing those pages on disk. Since OUTPUTDIR‘s layout can’t match that of the wiki, we make it match that of SOURCEDIR.)

  • SOURCEDIR OUTPUTDIR KEYID SECRET calls, and then posts the pages to MDN, using KEYID and SECRET to establish your identity. This posts only changed pages, so you can run it whenever the text you have is the right stuff to publish, without creating gratuitous churn in the MDN page history.

    To generate KEYID and SECRET, visit the MDN API key generation page.

Why not make the wiki the authoritative copy?

Storing documentation in the same tree as the sources it describes has several advantages:

  • It's easy to handle documentation changes as part of the same review process we use for code changes. A patch posted to Bugzilla can contain code, test, and doc changes, all of which can be discussed together.

  • The version control system that manages the code also manages its documentation. Branching the code (for Nightly, Aurora, Beta, or Release) branches the docs as well, so one can always find the docs that match the code in a given release stage.

  • Documentation for proposed changes has a natural home: in the patches that implement the change (or, at least, in a patch attached to the bug discussing the change). There's no need to include “(not yet implemented)” markers in the published docs.

Subdirectory layout and script interface

Alongside the documentation source files, the SOURCEDIR passed to should contain a file named describing the directory‘s contents, how to format them, and where they should be installed. This data is represented as executable shell code; and run the subdirectory’s script to learn what they should do.

The only effect of running a SOURCEDIR/ script should be to invoke the following commands:

base-url BASE : Treat BASE as the common prefix for some URLs appearing as arguments to subsequently executed commands (other than resource files). In describing the other commands, we use the metavariable RELATIVE-URL for URLs that are relative to BASE.

This command should appear before those taking RELATIVE-URL arguments.

BASE is treated as the root directory of the tree of formatted files.
If OUTPUTDIR is the output directory passed to `` or
``, then formatted files appear in OUTPUTDIR at the paths
they would appear on MDN relative to BASE.

markdown FILE RELATIVE-URL : Treat FILE as Markdown source for a documentation page to be published at RELATIVE-URL.

label LABEL [FRAGMENT] [TITLE] : Define a label for use in Markdown reference-style links referring to the file given in the preceding markdown command. If the second argument begins with a # character, it is taken to be an HTML fragment identifier; the link refers to that fragment in the page. TITLE, if present, is the title for the link.

For example:

    base-url https://devmo/Tools/
    markdown Debugger-API/Conventions
    label conventions "Debugger API: general conventions"
    label cv #completion-values "Debugger API: completion values"

would mean that `` should be processed to create
`https://devmo/Tools/Debugger-API/Conventions`; that Markdown files can
refer to that page like this:

    ... follows some [common conventions][conventions] which ...

and to the `#completion-values` fragment in that page like this:

    ... is passed a [completion value][cv] indicating ...

absolute-label LABEL URL [TITLE] : For reference-style links in this directory's Markdown files, define LABEL to refer to URL, an absolute URL. TITLE is an optional link title.

resource LABEL FILE URL : Treat FILE as a resource file (an image, for example) that should appear at URL. Since MDN likes to place “attachments” like images under different URL prefixes than the wiki pages themselves, URL is not relative to the BASE passed to base-url.

LABEL can be the empty string if no Markdown documents need to refer to
this resource file. (For example, the Markdown might use an SVG file,
which in turn use the resource file.)

Unfortunately, `` can't automatically post these resources to
MDN at the moment. However, it will check if the contents have changed,
and print a warning.

This ought to be integrated with mach

Indeed. It should somehow be unified with ‘mach build-docs’, which seems to format in-tree docs of a different kind, and use a different markup language (ReStructuredText) and a different formatter (Sphinx).