This removes special-casing of boxes from `rustc_pattern_analysis`, as a
first step in replacing `box_patterns` with `deref_patterns`.
Incidentally, it fixes a bug caused by box patterns being represented as
structs rather than pointers, where `exhaustive_patterns` could generate
spurious `unreachable_patterns` lints on arms required for
exhaustiveness; following the lint's advice would result in an error.
This was missed in b65c2afdfd, which only
enabled it for the glibc targets.
I didn't feel comfortable touching the OpenWRT target, whoever maintains
that will probably want to take a look whether it is necessary there as
well.
Signed-off-by: Jens Reidel <adrian@travitia.xyz>
compiler: Document and reduce `fn provide`s in hir crates
I found it hard to follow all these tiny micro-indirections. Much like you shouldn't pass around `&u32` if you can help it, you probably shouldn't use an indirection if the indirection overhead itself is literally bigger than the amount of data you are organizing. Generally a new `fn provide` amounts to around 3 LOC:
- the signature with opening brace
- the `rustc_middle::query::Providers` import
- an end brace
I am not even counting the cost in time and thought to go find the other `provide`, read it, understand, "Ah, yes, these functions", and then go to those. Thus I say we should collapse indirections of `provide` for modules that only export 1~2 queries. For higher-count indirections, I left them as-is, as I don't understand the crate well enough to judge their worth.
Then I dropped a pointer to the actual module of interest for all these instances of the same function. I think documenting them is important because the comment that it relates to the query system makes it obvious that they have **nothing** to do with the rest of the module's logic and I can carry on ignoring them. Actively doing so is another cognitive cost, but much more minimal.
There is also a small correctness issue in that all of these functions are technically mutating state. It's not a huge deal, but it's still easier to check all these mutations do not overlap if we have less instances of `fn provide` to check.
Fast path nitpicks
Miscellaneous commits that I didn't really want to fold into anything else.
Fixes one theoretical bug with the fast path not considering polarity for `T: !Sized` bounds.
We want to keep StableMIR definitions and logic separate from any sort of conversion and usage of internal rustc code. So we bundle all unstable items that have no stability guarantees into `stable_mir::unstable`.
add a new trait `InternalCx`, which defines the methods that are fine to call from `RustcInternal`. `RustcInternal::internal()` then takes a `impl InternalCx<'tcx>` instead of `TyCtxt<'tcx>`.
make `tcx` in `SmirCtxt` public, since we need to pass it to `RustcInternal::internal()` in `SmirInterface`.
note that this commit delete `convert/error.rs`, we would use `SmirError::from_internal` instead.
**Unresolved questions:**
- There are still a few direct calls to rustc's internals scattered across `impl Stable`s, but most of them appear to be relatively stable, e.g., `mir::interpret::ConstAllocation::inner(self)` and `mir::syntax::SwitchTargets::otherwise(self)`.
This commit removes the `Tables` field from `SmirCtxt`, since borrows of `tables` should only be managed by `SmirInterface`.
This change prevents `SmirCtxt` from holding separate borrows and requires passing `tables` explicitly when needed.
We use the `traits.rs` file to define traits that are used for encapsulating the associated functions in the rustc's internals. This is much easier to use and maintain than directly cramming everything into `SmirCtxt`.
The previous `rustc_smir::alloc` had many direct calls to rustc queries.
This commit splits it into two parts: `rustc_smir::alloc` and `stable_mir::alloc`.
Following the same pattern as `SmirCtxt` and `SmirInterface`, the `rustc_smir::alloc` handles all direct interactions with rustc queries and performs the actual memory allocations, while the `stable_mir::alloc` is responsible for constructing stable components.
- rewrite all `SmirInterface` apis.
- add `BridgeTys` to impl those associated types in `Bridge`.
- move `**_def()` stuffs living in `impl Tables` from `rustc_internal` to `stable_mir`.
MIR inliner maintains unused var_debug_info
Only `full` debuginfo level promises variable-level debug information, but the MIR inline pass needlessly preserved the local variable debug info for the `limited` level too.
Many small indirections with 1-2 items actively hinders understanding.
Inlines various tiny submodule provides into
- hir_analysis::provide
- hir_analysis::check::provide
- hir_typeck::provide
