MIR dumping is a mess. There are lots of functions and entry points,
e.g. `dump_mir`, `dump_mir_with_options`, `dump_polonius_mir`,
`dump_mir_to_writer`. Also, it's crucial that `create_dump_file` is
never called without `dump_enabled` first being checked, but there is no
mechanism for ensuring this and it's hard to tell if it is satisfied on
all paths. (`dump_enabled` is checked twice on some paths, however!)
This commit introduces `MirWriter`, which controls the MIR writing, and
encapsulates the `extra_data` closure and `options`. Two existing
functions are now methods of this type. It sets reasonable defaults,
allowing the removal of many `|_, _| Ok(())` closures.
The commit also introduces `MirDumper`, which is layered on top of
`MirWriter`, and which manages the creation of the dump files,
encapsulating pass names, disambiguators, etc. Four existing functions
are now methods of this type.
- `MirDumper::new` will only succeed if dumps are enabled, and will
return `None` otherwise, which makes it impossible to dump when you
shouldn't.
- It also sets reasonable defaults for various things like
disambiguators, which means you no longer need to specify them in many
cases. When they do need to be specified, it's now done via setter
methods.
- It avoids some repetition. E.g. `dump_nll_mir` previously specifed the
pass name `"nll"` four times and the disambiguator `&0` three times;
now it specifies them just once, to put them in the `MirDumper`.
- For Polonius, the `extra_data` closure can now be specified earlier,
which avoids having to pass some arguments through some functions.
The dynamic dispatch cost doesn't matter for MIR dumping, which is
perf-insensitive. And it's necessary for the next commit, which will
store some `extra_data` closures in a struct.
Currently they are skipped, which is a bit weird, and it sometimes
causes malformed output like `Foo<>` and `dyn Bar<, A = u32>`.
Most regions are erased by the time `type_name` does its work. So all
regions are now printed as `'_` in non-optional places. Not perfect, but
better than the status quo.
`c_name` is updated to trim lifetimes from MIR pass names, so that the
`PASS_NAMES` sanity check still works. It is also renamed as
`simplify_pass_type_name` and made non-const, because it doesn't need
to be const and the non-const implementation is much shorter.
The commit also renames `should_print_region` as
`should_print_optional_region`, which makes it clearer that it only
applies to some regions.
Fixes#145168.
Adds `#[rustc_force_inline]` which is similar to always inlining but
reports an error if the inlining was not possible, and which always
attempts to inline annotated items, regardless of optimisation levels.
It can only be applied to free functions to guarantee that the MIR
inliner will be able to resolve calls.
some const cleanup: remove unnecessary attributes, add const-hack indications
I learned that we use `FIXME(const-hack)` on top of the "const-hack" label. That seems much better since it marks the right place in the code and moves around with the code. So I went through the PRs with that label and added appropriate FIXMEs in the code. IMO this means we can then remove the label -- Cc ``@rust-lang/wg-const-eval.``
I also noticed some const stability attributes that don't do anything useful, and removed them.
r? ``@fee1-dead``
Because that's now the only crate that uses it.
Moving stuff out of `rustc_middle` is always welcome.
I chose to use `impl crate::MirPass`/`impl crate::MirLint` (with
explicit `crate::`) everywhere because that's the only mention of
`MirPass`/`MirLint` used in all of these files. (Prior to this change,
`MirPass` was mostly imported via `use rustc_middle::mir::*` items.)
MirPass: make name more const
Continues #120161, this time applied to `MirPass` instead of `MirLint`, locally shaves few (very few) instructions off.
r? ``@cjgillot``
Reevaluate `body.should_skip()` after updating the MIR phase to ensure
that injected MIR is processed correctly.
Update a few custom MIR tests that were ill-formed for the injected
phase.
This enhances documentation with these details and extends the validator to check these requirements
more thoroughly. As a part of this, we add a new `Deaggregated` phase, and rename other phases so
that their names more naturally correspond to what they represent.
This one is a heavy `'tcx` user.
Two interesting ones:
This one had the `'tcx` declared on the function, despite the trait taking a `'tcx`:
```diff
-impl Visitor<'_> for UsedLocals {
+impl<'tcx> Visitor<'tcx> for UsedLocals {
fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
```
This one use in-band for one, and underscore for the other:
```diff
-pub fn remove_dead_blocks(tcx: TyCtxt<'tcx>, body: &mut Body<'_>) {
+pub fn remove_dead_blocks<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
```
