Drop debug info instead of panicking if we exceed LLVM's capability to represent it
Recapping a bit of history here:
In #128861 I made debug info correctly represent parameters to inline functions by removing a fake lexical block that had been inserted to suppress LLVM assertions and by deduplicating those parameters.
LLVM, however, expects to see a single parameter _with distinct locations_, particularly distinct inlinedAt values on the DILocations. This generally worked because no matter how deep the chain of inlines it takes two different call sites in the original function to result in the same function being present multiple times, and a function call requires a non-zero number of characters, but macros threw a wrench in that in #131944. At the time I thought the issue there was limited to proc-macros, where an arbitrary amount of code can be generated at a single point in the source text.
In #132613 I added discriminators to DILocations that would otherwise be the same to repair #131944[^1]. This works, but LLVM's capacity for discriminators is not infinite (LLVM actually only allocates 12 bits for this internally). At the time I thought it would be very rare for anyone to hit the limit, but #132900 proved me wrong. In the relatively-minimized test case it also became clear to me that the issue affects regular macros too, because the call to the inlined function will (without collapse_debuginfo on the macro) be attributed to the (repeated, if the macro is used more than once) textual callsite in the macro definition.
This PR fixes the panic by dropping debug info when we exceed LLVM's maximum discriminator value. There's also a preceding commit for a related but distinct issue: macros that use collapse_debuginfo should in fact have their inlinedAts collapsed to the macro callsite and thus not need discriminators at all (and not panic/warn accordingly when the discriminator limit is exhausted).
Fixes#132900
r? `@jieyouxu`
[^1]: Editor's note: `fix` is a magic keyword in PR description that apparently will close the linked issue (it's closed already in this case, but still).
Default-enable `llvm_tools_enabled` when no `config.toml` is present
Fixes#133195. cc `@wesleywiser` could you double check if with this patch and no `config.toml` that you can run `./x test tests/ui --stage 1`?
`llvm-objcopy` is usually required by cg_ssa on macOS to workaround bad `strip`s.
cc `@bjorn3` I hope this doesn't break cg_clif...
r? bootstrap
Add `visit` methods to ast nodes that already have `walk`s on ast visitors
Some `walk` functions are called directly, because there were no correspondent visit functions.
related to #128974 & #127615
r? `@petrochenkov`
Rollup of 4 pull requests
Successful merges:
- #131081 (Use `ConstArgKind::Path` for all single-segment paths, not just params under `min_generic_const_args`)
- #132577 (Report the `unexpected_cfgs` lint in external macros)
- #133023 (Merge `-Zhir-stats` into `-Zinput-stats`)
- #133200 (ignore an occasionally-failing test in Miri)
r? `@ghost`
`@rustbot` modify labels: rollup
The maximum discriminator value LLVM can currently encode is 2^12. If macro use
results in more than 2^12 calls to the same function attributed to the same
callsite, and those calls are MIR-inlined, we will require more than the maximum
discriminator value to completely represent the debug information. Once we reach
that point drop the debug info instead.
The test relies on the fact that inlining more than 2^12 calls at the same
callsite will trigger a panic (and after the following commit, a warning) due to
LLVM limitations but with collapse_debuginfo the callsites should not be the
same.
`rustc_borrowck` cleanups, part 2
The code under `do_mir_borrowck` is pretty messy, especially the various types like `MirBorrowckCtxt`, `BorrowckInferCtxt`, `MirTypeckResults`, `MirTypeckRegionConstraints`, `CreateResult`, `TypeChecker`, `TypeVerifier`, `LivenessContext`, `LivenessResults`. This PR does some tidying up, though there's still plenty of mess left afterwards.
A sequel to #132250.
r? `@compiler-errors`
Merge `-Zhir-stats` into `-Zinput-stats`
Currently `-Z hir-stats` prints the size and count of various kinds of nodes, and the total size of all the nodes it counted, but not the total count of nodes. So, before this PR:
```
$ git clone https://github.com/BurntSushi/ripgrep
$ cd ripgrep
$ cargo +nightly rustc -- -Z hir-stats
ast-stats-1 PRE EXPANSION AST STATS
ast-stats-1 Name Accumulated Size Count Item Size
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 ...
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 Total 93_576
ast-stats-1
ast-stats-2 POST EXPANSION AST STATS
ast-stats-2 Name Accumulated Size Count Item Size
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 ...
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 Total 2_430_648
ast-stats-2
hir-stats HIR STATS
hir-stats Name Accumulated Size Count Item Size
hir-stats ----------------------------------------------------------------
hir-stats ...
hir-stats ----------------------------------------------------------------
hir-stats Total 3_678_512
hir-stats
```
For consistency, this PR adds a total for the count as well:
```
$ cargo +stage1 rustc -- -Z hir-stats
ast-stats-1 PRE EXPANSION AST STATS
ast-stats-1 Name Accumulated Size Count Item Size
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 ...
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 Total 93_576 1_877
ast-stats-1
ast-stats-2 POST EXPANSION AST STATS
ast-stats-2 Name Accumulated Size Count Item Size
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 ...
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 Total 2_430_648 48_625
ast-stats-2
hir-stats HIR STATS
hir-stats Name Accumulated Size Count Item Size
hir-stats ----------------------------------------------------------------
hir-stats ...
hir-stats ----------------------------------------------------------------
hir-stats Total 3_678_512 73_418
hir-stats
```
I wasn't sure if I was supposed to update `tests/ui/stats/hir-stats.stderr` to reflect this. I ran it locally, thinking it would fail, but it didn't:
```
$ ./x test tests/ui/stats
...
running 2 tests
i.
test result: ok. 1 passed; 0 failed; 1 ignored; 0 measured; 17949 filtered out
```
Also: is there a reason `-Z hir-stats` and `-Z input-stats` both exist? The former seems like it should completely supercede the latter. But strangely, the two give very different numbers for node counts:
```
$ cargo +nightly rustc -- -Z input-stats
...
Lines of code: 483
Pre-expansion node count: 2386
Post-expansion node count: 63844
```
That's a 30% difference in this case. Is it intentional that these numbers are so different? I see comments for both saying that they are merely approximations and should not be expected to be correct:
bd0826a452/compiler/rustc_ast_passes/src/node_count.rs (L1)bd0826a452/compiler/rustc_passes/src/hir_stats.rs (L1-L3)
Report the `unexpected_cfgs` lint in external macros
This PR marks the `unexpected_cfgs` lint as being reportable in external macros, as it's probably not the intention of the macro author to leave ineffective cfgs in the users code.
Fixes#132572
try-job: aarch64-gnu-debug
Use `ConstArgKind::Path` for all single-segment paths, not just params under `min_generic_const_args`
r? `@BoxyUwU`
edit by `@BoxyUwU:`
This PR introduces a `min_generic_const_args` feature gate and implements some preliminary work for it, representing all const arguments that are single segment paths as `ConstArg::Path` instead of only those that resolve to a const generic parameter. There are a few bits of follow up work after this lands:
- Figure out how to represent `Foo<{ STATIC }>`
- Figure out how to evaluate `Foo<{ EnumVariantConstructor }>`
- Make param env normalization handle non-anon-consts
- Move `try_from_lit` and `from_anon_const` to hir ty lowering too
It was added in #123752 to handle some cases involving emoji, but it
isn't necessary because it's always treated the same as
`TokenKind::InvalidIdent`. This commit removes it, which makes things a
little simpler.
- Rename it as `invalid_ident_or_prefix`, which matches the possible
outputs (`InvalidIdent` or `InvalidPrefix`).
- Use the local wrapper for `is_xid_continue`, for consistency.
- Make it clear what `\u{200d}` means.
Improve VecCache under parallel frontend
This replaces the single Vec allocation with a series of progressively larger buckets. With the cfg for parallel enabled but with -Zthreads=1, this looks like a slight regression in i-count and cycle counts (~1%).
With the parallel frontend at -Zthreads=4, this is an improvement (-5% wall-time from 5.788 to 5.4688 on libcore) than our current Lock-based approach, likely due to reducing the bouncing of the cache line holding the lock. At -Zthreads=32 it's a huge improvement (-46%: 8.829 -> 4.7319 seconds).
try-job: i686-gnu-nopt
try-job: dist-x86_64-linux
There is an `Rc<UniversalRegions>` within `UniversalRegionRelations`,
and yet the two types get passed around in tandem a lot.
This commit makes `UniversalRegionRelations` own `UniversalRegions`,
removing the `Rc` (which wasn't truly needed) and the tandem-passing.
This requires adding a `universal_relations` method to
`UniversalRegionRelations`, and renaming a couple of existing methods
producing iterators to avoid a name clash.
Use `TypingMode` throughout the compiler instead of `ParamEnv`
Hopefully the biggest single PR as part of https://github.com/rust-lang/types-team/issues/128.
## `infcx.typing_env` while defining opaque types
I don't know how'll be able to correctly handle opaque types when using something taking a `TypingEnv` while defining opaque types. To correctly handle the opaques we need to be able to pass in the current `opaque_type_storage` and return constraints, i.e. we need to use a proper canonical query. We should migrate all the queries used during HIR typeck and borrowck where this matters to proper canonical queries. This is
## `layout_of` and `Reveal::All`
We convert the `ParamEnv` to `Reveal::All` right at the start of the `layout_of` query, so I've changed callers of `layout_of` to already use a post analysis `TypingEnv` when encountering it.
ca87b535a0/compiler/rustc_ty_utils/src/layout.rs (L51)
## `Ty::is_[unpin|sized|whatever]`
I haven't migrated `fn is_item_raw` to use `TypingEnv`, will do so in a followup PR, this should significantly reduce the amount of `typing_env.param_env`. At some point there will probably be zero such uses as using the type system while ignoring the `typing_mode` is incorrect.
## `MirPhase` and phase-transitions
When inside of a MIR-body, we can mostly use its `MirPhase` to figure out the right `typing_mode`. This does not work during phase transitions, most notably when transitioning from `Analysis` to `Runtime`:
dae7ac133b/compiler/rustc_mir_transform/src/lib.rs (L606-L625)
All these passes still run with `MirPhase::Analysis`, but we should only use `Reveal::All` once we're run the `RevealAll` pass. This required me to manually construct the right `TypingEnv` in all these passes. Given that it feels somewhat easy to accidentally miss this going forward, I would maybe like to change `Body::phase` to an `Option` and replace it at the start of phase transitions. This then makes it clear that the MIR is currently in a weird state.
r? `@ghost`
