rustdoc: Add more semantic information to impl IDs

[pierwill]

Instead of generating #impl, #impl-1, etc., generate IDs like #impl-Foo<M>.

Part of #92052.

[rust-highfive]

r? @GuillaumeGomez

(rust-highfive has picked a reviewer for you, use r? to override)

[pierwill]

@rustbot author

[pierwill]

r? @camelid

[pierwill]

@rustbot ready

[camelid]

Can you update the tests?

@rustbot author

[pierwill]

Can you update the tests?

@rustbot author

Should x test src/test/rustdoc --bless work for this? I am getting many errors that don't seem related...

[camelid]

No, you'll need to update the @has comments manually. Basically, go through each test that fails, and update the comments starting with @has so the expected URL fragment (the #foo or id="foo" part) is what you expect after your change.

[pierwill]

I'm getting panics on at least one test that has no @has:

---- [rustdoc] rustdoc/async-move-doctest.rs stdout ----

error: rustdoc failed!
status: exit status: 101
command: "/Users/user/repos/rust/build/x86_64-apple-darwin/stage1/bin/rustdoc" "-L" "/Users/user/repos/rust/build/x86_64-apple-darwin/stage1/lib/rustlib/x86_64-apple-darwin/lib" "-L" "/Users/user/repos/rust/build/x86_64-apple-darwin/test/rustdoc/async-move-doctest/auxiliary" "-o" "/Users/user/repos/rust/build/x86_64-apple-darwin/test/rustdoc/async-move-doctest" "--deny" "warnings" "/Users/user/repos/rust/src/test/rustdoc/async-move-doctest.rs" "--test" "--edition=2018"
stdout:
------------------------------------------

------------------------------------------
stderr:
------------------------------------------
thread 'rustc' panicked at 'SESSION_GLOBALS should never be overwritten! Use another thread if you need another SessionGlobals', /Users/user/repos/rust/compiler/rustc_span/src/lib.rs:103:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.60.0-dev running on x86_64-apple-darwin

query stack during panic:
end of query stack

------------------------------------------

[camelid]

Hmm, try rm -r build/<your-machine-arch>/stage* and then re-running tests. Might just be corruption in your build directory.

[pierwill]

Still getting nasty panics. 😬

[camelid]

Weird, what's your config.toml?

[pierwill]

# Includes one of the default files in src/bootstrap/defaults
profile = "compiler"
changelog-seen = 2

[rust]
incremental = true

# deny-warnings = false

debug = true
debug-assertions = false
debuginfo-level = 1
debuginfo-level-rustc = 1
debuginfo-level-std = 1

run-dsymutil = false

parallel-compiler = true

[build]
compiler-docs = true

[camelid]

Oh, parallel-compiler doesn't work properly. You should disable it. I think that's what's causing the panics.

I'm curious, why did you enable it? Did you see it recommended somewhere?

[pierwill]

Not sure how we want to handle this. @GuillaumeGomez

[GuillaumeGomez]

If the result appears, then it means the search filter is broken. Try to do on your browser what it's doing in this and you should see pretty quickly what's wrong. If you can't figure it out, I can take a look in the next days.

Please revert this change in any case.

[pierwill]

Reverted.

[GuillaumeGomez]

Nice!

[camelid]

Ok, now you're seeing all the broken links in the standard library 😅

Before you go to the effort to update all of those, we should get confirmation from the team that this new anchor formatting looks good to them.

[GuillaumeGomez]

I said it on zulip but doesn't hurt to say it here as well: I agree with this change (good luck updating all std URLs 😉 ).

[pierwill]

@rustbot author

[jsha]

I've put up a demo of this branch at https://rustdoc.crud.net/jsha/rustdoc-disamb-impls/std/fs/struct.File.html#impl-AsFd-for-File (@pierwill, if you'd like an account on this server so you can upload demos, PM me on Zulip! I'm @jsha there too).

I spotted the broken links issue. If you look in the sidebar for AsFd, and click on it, you're taken to https://rustdoc.crud.net/jsha/rustdoc-disamb-impls/std/fs/struct.File.html#impl-AsFd. But the new fragment is #impl-AsFd-for-File, so that's a broken link.

I think this is the code you need to tweak:

rust/src/librustdoc/html/render/mod.rs

Lines 2012 to 2033 in 48e89b0

	let format_impls = |impls: Vec<&Impl>| {
	let mut links = FxHashSet::default();
	let mut ret = impls
	.iter()
	.filter_map(|it| {
	if let Some(ref i) = it.inner_impl().trait_ {
	let i_display = format!("{:#}", i.print(cx));
	let out = Escape(&i_display);
	let encoded = small_url_encode(format!("{:#}", i.print(cx)));
	let prefix = match it.inner_impl().polarity {
	ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
	ty::ImplPolarity::Negative => "!",
	};
	let generated =
	format!("<a href=\"#impl-{}\">{}{}</a>", encoded, prefix, out);
	if links.insert(generated.clone()) { Some(generated) } else { None }
	} else {
	None
	}
	})
	.collect::<Vec<String>>();

.

[pierwill]

I do still want to finish this. 🤓

[bors]

☔ The latest upstream changes (presumably #93655) made this pull request unmergeable. Please resolve the merge conflicts.

[JohnCSimon]

@pierwill

Ping from triage: I'm closing this due to inactivity, Please reopen when you are ready to continue with this.
Note: if you do please open the PR BEFORE you force push to it, else you won't be able to reopen.
Thanks for your contribution.

@rustbot label: +S-inactive