Add test for old compiler ICE when using `Borrow`
The original issue was caused by implementing `Borrow` on a local type and using the tokio-reactor crate which had this impl: https://github.com/tokio-rs/tokio/blob/tokio-0.1.4/tokio-reactor/src/poll_evented.rs#L547-L577
This causes an ICE on Rust 1.27.0:
```console
$ RUSTUP_TOOLCHAIN=1.27.0 rustc src/test/ui/issues/issue-50687-ice-on-borrow.rs
error: internal compiler error: librustc/traits/structural_impls.rs:180: impossible case reached
thread 'main' panicked at 'Box<Any>', librustc_errors/lib.rs:554:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.
error: aborting due to previous error
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.27.0 (3eda71b00 2018-06-19) running on x86_64-apple-darwin
```
Closes#50687
Warn about unused crate deps
Implements #57274 by adding -Wunused-crate-dependencies. This will warn about any `--extern` option on the command line which isn't referenced by the crate source either via `use` or `extern crate`.
Crates which are added for some side effect but are otherwise unreferenced - such as for symbols they define - the warning can be suppressed with `use somecrate as _;`.
If a crate has multiple aliases (eg using `foo = { package = "bar" }` in `Cargo.toml`), then it will warn about each unused alias.
This does not consider crate added by some other means than `--extern`, including the standard library. It also doesn't consider any crate without `add_prelude` set (though I'm not sure about this).
Unfortunately this probably [does not yet work well with Cargo](https://github.com/rust-lang/rust/issues/57274#issuecomment-624839355) as it will over-specify crates, causing spurious warnings. As a result, this lint is "allow" by default and must be explicitly enabled either via `#![warn(unused_crate_deps)]` or with `-Wunused-crate-deps`.
add a lint against references to packed fields
Creating a reference to an insufficiently aligned packed field is UB and should be disallowed, both inside and outside of `unsafe` blocks. However, currently there is no stable alternative (https://github.com/rust-lang/rust/issues/64490) so all we do right now is have a future incompatibility warning when doing this outside `unsafe` (https://github.com/rust-lang/rust/issues/46043).
This adds an allow-by-default lint. @retep998 suggested this can help early adopters avoid issues. It also means we can then do a crater run where this is deny-by-default as suggested by @joshtriplett.
I guess the main thing to bikeshed is the lint name. I am not particularly happy with "packed_references" as it sounds like the packed field has reference type. I chose this because it is similar to "safe_packed_borrows". What about "reference_to_packed" or "unaligned_reference" or so?
This commit attempts to improve reproducibility of builds on macOS by
exporting the `ZERO_AR_DATE=1` environment variable for all invocations
of the linker. While it looks like this env var is targeted at just the
`ar` command (which does actually read this) it appears that recent-ish
versions of the linker *also* read this environment variable. This
env var forces the linker to set a deterministic zero value for the
mtime in the N_OSO field of the object file.
Currently it's believe that older versions of the linker will simply
ignore this env var, while newer versions will read it and produce a
deterministic output for compilations with debuginfo.
Closes#47086Closes#66568
This will print a diagnostic for crates which are mentioned as `--extern`
arguments on the command line, but are never referenced from the source.
This diagnostic is controlled by `-Wunused-crate-dependencies` or
`#![warn(unused_crate_dependencies)]` and is "allow" by default.
There are cases where certain crates need to be linked in but are not
directly referenced - for example if they are providing symbols for C
linkage. In this case the warning can be suppressed with
`use needed_crate as _;`.
Thanks to @petrochenkov for simplified core.
Resolves issue #57274
Fix bug in shebang handling
Shebang handling was too agressive in stripping out the first line in cases where it is actually _not_ a shebang, but instead, valid rust (#70528). This is a second attempt at resolving this issue (the first attempt was reverted, for, among other reasons, causing an ICE in certain cases (#71372, #71471).
The behavior is now codified by a number of UI tests, but simply:
For the first line to be a shebang, the following must all be true:
1. The line must start with `#!`
2. The line must contain a non-whitespace character after `#!`
3. The next character in the file, ignoring comments & whitespace must not be `[`
I believe this is a strict superset of what we used to allow, so perhaps a crater run is unnecessary, but probably not a terrible idea.
Fixes#70528
add regression tests for stalled_on const vars
closes#70180
Afaict this has been fixed sometime after #70213
`trait_ref_type_vars` correctly adds const infers and I did not find any remaining `FIXME`s which correspond to this issue.
7c59a81a5f/src/librustc_trait_selection/traits/fulfill.rs (L555-L557)
Added both examples from the issue as regression tests and renamed `trait_ref_type_vars` -> `trait_ref_infer_vars`.
r? @eddyb
Rollup of 4 pull requests
Successful merges:
- #72153 (exhaustively check `ty::Kind` during structural match checking)
- #72308 (Emit a better diagnostic when function actually has a 'self' parameter)
- #72560 (Enable `glacier` command via triagebot)
- #72567 (Clean up E0608 explanation)
Failed merges:
r? @ghost
Emit a better diagnostic when function actually has a 'self' parameter
Fixes#66898
When we are unable to resolve a reference to `self`, we current assume
that the containing function doesn't have a `self` parameter, and
emit an error message accordingly.
However, if the reference to `self` was created by a macro invocation,
then resolution will correctly fail, due to hygiene. In this case, we
don't want to tell the user that the containing fuction doesn't have a
'self' paramter if it actually has one.
This PR checks for the precense of a 'self' parameter, and adjusts the
error message we emit accordingly.
TODO: The exact error message we emit could probably be improved. Should
we explicitly mention hygiene?
exhaustively check `ty::Kind` during structural match checking
This was prone to errors as we may forget new kinds in the future.
I am also not yet sure about some kinds.
`ty::GeneratorWitness(..) | ty::Infer(_) | ty::Placeholder(_) | ty::UnnormalizedProjection(..) | ty::Bound(..)` might be unreachable here.
We may want to forbid `ty::Projection`, similar to `ty::Param`.
`ty::Opaque` seems fine afaict, should not be possible in a match atm.
I believe `ty::Foreign` should not be structurally match, as I don't even know what
that would actually mean.
r? @pnkfelix cc @eddyb
Shebang handling was too agressive in stripping out the first line in cases where it is actually _not_ a shebang, but instead, valid rust (#70528). This is a second attempt at resolving this issue (the first attempt was flawed, for, among other reasons, causing an ICE in certain cases (#71372, #71471).
The behavior is now codified by a number of UI tests, but simply:
For the first line to be a shebang, the following must all be true:
1. The line must start with `#!`
2. The line must contain a non whitespace character after `#!`
3. The next character in the file, ignoring comments & whitespace must not be `[`
I believe this is a strict superset of what we used to allow, so perhaps a crater run is unnecessary, but probably not a terrible idea.
Rewrite `Parser::collect_tokens`
The previous implementation did not work when called on an opening
delimiter, or when called re-entrantly from the same `TokenCursor` stack
depth.
I'm not sure how to test this apart from https://github.com/rust-lang/rust/pull/72287
Recursively expand `TokenKind::Interpolated` in `probably_equal_for_proc_macro`
Fixes#68430
When comparing the captured and re-parsed `TokenStream` for a `TokenKind::Interpolated`, we currently treat any nested `TokenKind::Interpolated` tokens as unequal. If a `TokenKind::Interpolated` token shows up in the captured `TokenStream` due to a `macro_rules!` expansion, we will throw away the captured `TokenStream`, losing span information.
This PR recursively invokes `nt_to_tokenstream` on nested `TokenKind::Interpolated` tokens, effectively flattening the stream into a sequence of non-interpolated tokens. This allows it to compare equal with the re-parsed stream, allowing us to keep the original captured `TokenStream` (with span information).
This requires all of the `probably_equal_for_proc_macro` methods to be moved from `librustc_ast` to `librustc_parse` so that they can call `nt_to_tokenstream`.
Remove ReScope
`ReScope` is unnecessary now that AST borrowck is gone and we're erasing the results of region inference in function bodies. This removes about as much of the old regionck code as possible without having to enable NLL fully.
cc #68261
r? @nikomatsakis
fix discriminant type in generator transform
The generator transform assumed that the discriminant type is always `isize`, which is not correct, leading to [ICEs in Miri](https://github.com/rust-lang/rust/pull/72419/files#r429543536) when some extra sanity checking got enabled.
r? @jonas-schievink @eddyb
Add missing ASM arena declarations to librustc_middle
Fixes#72386
These types also need to get allocated on the `librustc_middle` arena
when we deserialize MIR.
@Amanieu: If we end up using your approach in https://github.com/rust-lang/rust/pull/72392 instead, feel free to copy the test I added over to your PR.
Preserve substitutions when making trait obligations for suggestions
Resolves#71394.
I *think* `map_bound_ref` is correct here. In any case, I think a lot of the diagnostic code is using `skip_binder` more aggressively than it should be, so I doubt that this is worse than the status quo. The assertion that `new_self_ty` has no escaping bound vars should be enough.
r? @estebank
cc @nikomatsakis Is the call to `skip_binder` on line 551 (and elsewhere in this file) appropriate? 46ec74e60f/src/librustc_trait_selection/traits/error_reporting/suggestions.rs (L537-L565)
