Such implementations are usually mistakes and are not used in the
compiler or standard library (after this commit) so forbid them with
`min_specialization`.
Improve check-cfg implementation
This PR makes multiple improvements into the implementation of check-cfg, it is a prerequisite to a follow-up PR that will introduce a simpler and more explicit syntax.
The 2 main area of improvements are:
1. Internal representation of expected values:
- now uses `FxHashSet<Option<Symbol>>` instead of `FxHashSet<Symbol>`, it made the no value expected case only possible when no values where in the `HashSet` which is now represented as `None` (same as cfg represent-it).
- a enum with `Some` and `Any` makes it now clear if some values are expected or not, necessary for `feature` and `target_feature`.
2. Diagnostics: Improve the diagnostics in multiple case and fix case where a missing value could have had a new name suggestion instead of the value diagnostic; and some drive by improvements
I highly recommend reviewing commit by commit.
r? `@petrochenkov`
Reduce MIR dump file count for MIR-opt tests
As referenced in issue #109502 , mir-opt tests previously used the -Zdump-mir=all flag, which generates very large output. This PR only dumps the passes under test, greatly reducing dump output.
Fix problems with backtraces in two ui tests.
`default-backtrace-ice.rs` started started failing for me recently,
because on my Ubuntu 23.04 system there are 100 stack frames, and the
current stack filtering pattern doesn't match on a stack frame with a
three digit number.
`issue-86800.rs` can also be improved, backtrace-wise.
r? `@Nilstrieb`
This test is supposed to ensure that full backtraces are used for ICEs.
But it doesn't actually do that -- the filtering done cannot distinguish
between a full backtrace versus a short backtrace.
So this commit changes the filtering to preserve the existence of
`__rust_{begin,end}_short_backtrace` markers, which only appear in full
backtraces. This change means the test now tests what it is supposed to
test.
Also, the existing filtering included a rule that excluded any line
starting with two spaces. This was too strong because it filtered out
some parts of the error message. (This was not a showstopper). It was
also not strong enough because it didn't work with three digit stack
frame numbers, which just started seeing after upgrading my Ubuntu
distro to 23.04 machine (this *was* a showstopper).
So the commit replaces that rule with two more precise rules, one for
lines with stack frame numbers, and one for "at ..." lines.
Because it then just has to be filtered out.
This change makes this test more like these other tests:
- tests/ui/treat-err-as-bug/err.rs
- tests/ui/treat-err-as-bug/delay_span_bug.rs
- tests/ui/mir/validate/storage-live.rs
- tests/ui/associated-inherent-types/bugs/ice-substitution.rs
- tests/ui/layout/valid_range_oob.rs
check array type of repeat exprs is wf
Fixes#111091
Also makes sure that we actually renumber regions in the length of repeat exprs which we previously weren't doing and would cause ICEs in `adt_const_params` + `generic_const_exprs` from attempting to prove the wf goals when the length was an unevaluated constant with `'erased` in the `ty` field of `Const`
The duplicate errors are caused by the fact that `const_arg_to_const`/`array_len_to_const` in `FnCtxt` adds a `WellFormed` goal for the created `Const` which is also checked by the added `WellFormed(array_ty)`. I don't want to change this to just emit a `T: Sized` goal for the element type since that would ignore `ConstArgHasType` wf requirements and generally uncomfortable with the idea of trying to sync up `wf::obligations` for arrays and the code in hir typeck for repeat exprs.
r? `@compiler-errors`
