The lint definitions use macros heavily. This commit merges some of them
that are split unnecessarily. I find the reduced indirection makes it
easier to imagine what the generated code will look like.
The old version of this code specified a bunch of different numbers that had
to line up just right to get the size it wanted. This version uses flexbox
centering, specifies the font size, and lets the browser figure out the
rest of the layout automatically.
Lower them into a single item with multiple resolutions instead.
This also allows to remove additional `NodId`s and `DefId`s related to those additional items.
rustdoc: remove redundant CSS `div.desc { display: block }`
DIV tags have block display by default. It is from when this rule used to target a SPAN tag, but became redundant in 4bd6748bb9b73c210558498070ae0b7ed8193ddf.
`#![custom_mir]`: Various improvements
This PR makes a bunch of improvements to `#![custom_mir]`. Ideally this would be 4 PRs, one for each commit, but those would take forever to get merged and be a pain to juggle. Should still be reviewed one commit at a time though.
### Commit 1: Support arbitrary `let`
Before this change, all locals used in the body need to be declared at the top of the `mir!` invocation, which is rather annoying. We attempt to change that.
Unfortunately, we still have the requirement that the output of the `mir!` macro must resolve, typecheck, etc. Because of that, we can't just accept this in the THIR -> MIR parser because something like
```rust
{
let x = 0;
Goto(other)
}
other = {
RET = x;
Return()
}
```
will fail to resolve. Instead, the implementation does macro shenanigans to find the let declarations and extract them as part of the `mir!` macro. That *works*, but it is fairly complicated and degrades debuginfo by quite a bit. Specifically, the spans for any statements and declarations that are affected by this are completely wrong. My guess is that this is a net improvement though.
One way to recover some of the debuginfo would be to not support type annotations in the `let` statements, which would allow us to parse like `let $stmt:stmt`. That seems quite surprising though.
### Commit 2: Parse consts
Reuses most of the const parsing from regular Mir building for building custom mir
### Commit 3: Parse statics
Statics are slightly weird because the Mir primitive associated with them is a reference/pointer to them, so this is factored out separately.
### Commit 4: Fix some spans
A bunch of the spans were non-ideal, so we adjust them to be much more helpful.
r? `@oli-obk`
This makes sure that ICEing because of def ids created outside of ast lowering will be able to produce a query backtrace and not cause a double panic because of trying to call the `def_span` query
refactor scheduler
Refactors the scheduler to use something akin to a generator -- a callback that will be invoked when the stack of a thread is empty, which has the chance to push a new stack frame or do other things and then indicates whether this thread is done, or should be scheduled again. (Unfortunately I think we [cannot use actual generators](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Generators.20that.20borrow.20on.20each.20resume.3F) here.) The interpreter loop is now a proper infinite loop, the only way to leave it is for some kind of interrupt to be triggered (represented as `InterpError`) -- unifying how we handle 'exit when calling `process::exit`' and 'exit when main thread quits'.
The last commit implements an alternative approach to https://github.com/rust-lang/miri/pull/2660 using this new structure. Fixes https://github.com/rust-lang/miri/issues/2629.
Pointer-integer casts are required for conversion between `EXINF` (ITRON
task entry point parameter) and `*const ThreadInner`. Addresses the
deny-level lint `fuzzy_provenance_casts`.
