Implement rust-lang/compiler-team#578.
When an ICE is encountered on nightly releases, the new rustc panic
handler will also write the contents of the backtrace to disk. If any
`delay_span_bug`s are encountered, their backtrace is also added to the
file. The platform and rustc version will also be collected.
Better diagnostics for dlltool errors.
When dlltool fails, show the full command that was executed. In particular, llvm-dlltool is not very helpful, printing a generic usage message rather than what actually went wrong, so stdout and stderr aren't of much use when troubleshooting.
allow opaques to be defined by trait queries, again
This basically reverts #112963.
Moreover, all call-sites of `enter_canonical_trait_query` can now define opaque types, see the ui test `defined-by-user-annotation.rs`.
Fixes#113689
r? `@compiler-errors` `@oli-obk`
Instead of repeatedly merging the two smallest CGUs, we now use a
merging algorithm that aims to minimize the duplication of inlined
functions.
`exa-0.10.1` was one benchmark that saw particularly good results. The
old CGU stats:
```
INTERNALIZE
- unique items: 2774 (1216 root + 1558 inlined), unique size: 122065 (77219 root + 44846 inlined)
- placed items: 3834 (1216 root + 2618 inlined), placed size: 154552 (77219 root + 77333 inlined)
- placed/unique items ratio: 1.38, placed/unique size ratio: 1.27
- CGUs: 16, mean size: 9659.5, sizes: [11791, 11634, 11173, 10987, 10939, 10507, 9992, 9813, 9593, 9580, 9030, 8447, 7975, 7961, 7876, 7254]
```
The new CGU stats:
```
INTERNALIZE
- unique items: 2774 (1216 root + 1558 inlined), unique size: 122065 (77219 root + 44846 inlined)
- placed items: 3626 (1216 root + 2410 inlined), placed size: 147201 (77219 root + 69982 inlined)
- placed/unique items ratio: 1.31, placed/unique size ratio: 1.21
- CGUs: 16, mean size: 9200.1, sizes: [11634, 10939, 10227, 9555, 9178, 9167, 8879, 8804, 8604, 8603 (x3), 8602 (x2), 8601, 8600]
```
The difference is in the number of inlined items. There are 1558 unique
inlined items. With the old algorithm these were placed 2618 times,
resulting in 1060 duplicates. With the new algorithm these were placed
2410 times, resulting in 852 duplicates. Also, the mean CGU size dropped
from 9659.5 to 9200.1, and the CGU size distribution tightened, with the
biggest one a little smaller and the smallest ones a little bigger.
Restrict recursive opaque type check
We have a recursive opaque check in writeback to avoid inferring the hidden of an opaque type to be itself:
33a2c2487a/compiler/rustc_hir_typeck/src/writeback.rs (L556-L575)
Issue #113619 treats `make_option2` as not defining the TAIT `TestImpl` since it is inferred to have the definition `TestImpl := B<TestImpl>`, which fails this check. This regressed in #102700 (5d15beb591), I think due to the refactoring that made us record the hidden types of TAITs during writeback.
However, nothing actually seems to go bad if we relax this recursion checker to only check for directly recursive definitions. This PR fixes#113619 by changing this recursive check from being a visitor to just checking that the hidden type is exactly the same as the opaque being inferred.
Alternatively, we may be able to fix#113619 by restricting this recursion check only to RPITs/async fns. It seems to only be possible to use misuse the recursion check to cause ICEs for TAITs (though I didn't try too hard to create a bad RPIT example... may be possible, actually.)
r? `@oli-obk`
--
Fixes#113314
Fix removal span calculation of `unused_qualifications` suggestion
Given a path such as `std::ops::Index<str>`, calculate the unnecessary qualification removal span by computing the beginning of the entire span until the ident span of the last path segment, which handles generic arguments and lifetime arguments in the last path segment. Previous logic only kept the ident span of the last path segment which is incorrect.
Closes#113808.
add mips64r6 and mips32r6 as target_arch values
This PR introduces `"mips32r6"` and `"mips64r6"` as valid `target_arch` values, and would be the arch value used by Tier-3 targets `mipsisa32r6-unknown-linux-gnu`, `mipsisa32r6el-unknown-linux-gnu`, `mipsisa64r6-unknown-linux-gnuabi64` and `mipsisa64r6el-unknown-linux-gnuabi64`.
This PR was inspired by `rustix` attempting to link traditional mips64el objects with mips64r6el objects when building for mips64r6, even though `rustix` recently removed outline assembly support. This is because currently this target's `target_arch` is `"mips64"` and rustix has its respective assembly implementation as well as a pre-compiled little-endian static library prepared for mips64el, a tier-2 target with the same `target_arch`. After some [discussions on zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/Add.20New.20Values.20To.20MIPS_ALLOWED_FEATURES.20compiler-team.23595), I decided to treat mips64r6 as an independent architecture from Rust's POV, since these two architectures are incompatible anyway.
This PR is now waiting for `libc` to release a new version with [support](https://github.com/rust-lang/libc/pull/3268) for these `target_arch` values. It is not expected to introduce changes to any other target, especially Tier-1 and Tier-2 targets.
This PR has its corresponding [MCP](https://github.com/rust-lang/compiler-team/issues/632) approved.
