Skip to content

Commit

Permalink
docgen: implement cross-document links (#20990)
Browse files Browse the repository at this point in the history
* docgen: implement cross-document links

Fully implements nim-lang/RFCs#125
Follow-up of: #18642 (for internal links)
and #20127.

Overview
--------

Explicit import-like directive is required, called `.. importdoc::`.
(the syntax is % RST, Markdown will use it for a while).

Then one can reference any symbols/headings/anchors, as if they
were in the local file (but they will be prefixed with a module name
or markup document in link text).
It's possible to reference anything from anywhere (any direction
in `.nim`/`.md`/`.rst` files).

See `doc/docgen.md` for full description.

Working is based on `.idx` files, hence one needs to generate
all `.idx` beforehand. A dedicated option `--index:only` is introduced
(and a separate stage for `--index:only` is added to `kochdocs.nim`).

Performance note
----------------

Full run for `./koch docs` now takes 185% of the time before this PR.
(After: 315 s, before: 170 s on my PC).
All the time seems to be spent on `--index:only` run, which takes
almost as much (85%) of normal doc run -- it seems that most time
is spent on file parsing, turning off HTML generation phase has not
helped much.
(One could avoid it by specifying list of files that can be referenced
and pre-processing only them. But it can become error-prone and I assume
that these linke will be **everywhere** in the repository anyway,
especially considering nim-lang/RFCs#478.
So every `.nim`/`.md` file is processed for `.idx` first).

But that's all without significant part of repository converted to
cross-module auto links. To estimate impact I checked the time for
`doc`ing a few files (after all indexes have been generated), and
everywhere difference was **negligible**.
E.g. for `lib/std/private/osfiles.nim` that `importdoc`s large
`os.idx` and hence should have been a case with relatively large
performance impact, but:

* After: 0.59 s.
* Before: 0.59 s.

So Nim compiler works so slow that doc part basically does not matter :-)

Testing
-------

1) added `extlinks` test to `nimdoc/`
2) checked that `theindex.html` is still correct
2) fixed broken auto-links for modules that were derived from `os.nim`
   by adding appropriate ``importdoc``

Implementation note
-------------------

Parsing and formating of `.idx` entries is moved into a dedicated
`rstidx.nim` module from `rstgen.nim`.

`.idx` file format changed:

* fields are not escaped in most cases because we need original
  strings for referencing, not HTML ones
  (the exception is linkTitle for titles and headings).
  Escaping happens later -- on the stage of `rstgen` buildIndex, etc.
* all lines have fixed number of columns 6
* added discriminator tag as a first column,
  it always allows distinguish Nim/markup entries, titles/headings, etc.
  `rstgen` does not rely any more (in most cases) on ad-hoc logic
  to determine what type each entry is.
* there is now always a title entry added at the first line.
* add a line number as 6th column
* linkTitle (4th) column has a different format: before it was like
  `module: funcName()`, now it's `proc funcName()`.
  (This format is also propagated to `theindex.html` and search results,
  I kept it that way since I like it more though it's discussible.)
  This column is what used for Nim symbols resolution.
* also changed details on column format for headings and titles:
  "keyword" is original, "linkTitle" is HTML one

* fix paths on Windows + more clear code

* Update compiler/docgen.nim

Co-authored-by: Andreas Rumpf <[email protected]>

* Handle .md and .nim paths uniformly in findRefFile

* handle titles better + more comments

* don't allow markup overwrite index title for .nim files

Co-authored-by: Andreas Rumpf <[email protected]>
  • Loading branch information
a-mr and Araq authored Jan 4, 2023
1 parent b2328b4 commit 2620da9
Show file tree
Hide file tree
Showing 45 changed files with 1,866 additions and 494 deletions.
8 changes: 7 additions & 1 deletion compiler/commands.nim
Original file line number Diff line number Diff line change
Expand Up @@ -820,7 +820,13 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
if conf != nil: conf.headerFile = arg
incl(conf.globalOptions, optGenIndex)
of "index":
processOnOffSwitchG(conf, {optGenIndex}, arg, pass, info)
case arg.normalize
of "", "on": conf.globalOptions.incl {optGenIndex}
of "only": conf.globalOptions.incl {optGenIndexOnly, optGenIndex}
of "off": conf.globalOptions.excl {optGenIndex, optGenIndexOnly}
else: localError(conf, info, errOnOrOffExpectedButXFound % arg)
of "noimportdoc":
processOnOffSwitchG(conf, {optNoImportdoc}, arg, pass, info)
of "import":
expectArg(conf, switch, arg, pass, info)
if pass in {passCmd2, passPP}:
Expand Down
200 changes: 145 additions & 55 deletions compiler/docgen.nim

Large diffs are not rendered by default.

2 changes: 2 additions & 0 deletions compiler/lineinfos.nim
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@ type
warnRstBrokenLink = "BrokenLink",
warnRstLanguageXNotSupported = "LanguageXNotSupported",
warnRstFieldXNotSupported = "FieldXNotSupported",
warnRstUnusedImportdoc = "UnusedImportdoc",
warnRstStyle = "warnRstStyle",
warnCommentXIgnored = "CommentXIgnored",
warnTypelessParam = "TypelessParam",
Expand Down Expand Up @@ -142,6 +143,7 @@ const
warnRstBrokenLink: "broken link '$1'",
warnRstLanguageXNotSupported: "language '$1' not supported",
warnRstFieldXNotSupported: "field '$1' not supported",
warnRstUnusedImportdoc: "importdoc for '$1' is not used",
warnRstStyle: "RST style: $1",
warnCommentXIgnored: "comment '$1' ignored",
warnTypelessParam: "", # deadcode
Expand Down
2 changes: 2 additions & 0 deletions compiler/options.nim
Original file line number Diff line number Diff line change
Expand Up @@ -78,6 +78,8 @@ type # please make sure we have under 32 options
optThreadAnalysis, # thread analysis pass
optTlsEmulation, # thread var emulation turned on
optGenIndex # generate index file for documentation;
optGenIndexOnly # generate only index file for documentation
optNoImportdoc # disable loading external documentation files
optEmbedOrigSrc # embed the original source in the generated code
# also: generate header file
optIdeDebug # idetools: debug mode
Expand Down
4 changes: 3 additions & 1 deletion doc/advopt.txt
Original file line number Diff line number Diff line change
Expand Up @@ -130,7 +130,9 @@ Advanced options:
select which memory management to use; default is 'orc'
--exceptions:setjmp|cpp|goto|quirky
select the exception handling implementation
--index:on|off turn index file generation on|off
--index:on|off|only docgen: turn index file generation? (`only` means
not generate output files like HTML)
--noImportdoc:on|off disable loading documentation ``.idx`` files?
--putenv:key=value set an environment variable
--NimblePath:PATH add a path for Nimble support
--noNimblePath deactivate the Nimble path
Expand Down
Loading

0 comments on commit 2620da9

Please sign in to comment.