Use ident.span instead of def_span in dead-code pass
Hello! First time contributor! :)
This should fix#58729.
According to @estebank in the duplicate #63064, def_span scans forward on the line until it finds a {,
and if it can't find one, falls back to the span for the whole item. This
was apparently written before the identifier span was explicitly tracked on
each node.
This means that if an unused function signature spans multiple lines, the
entire function (potentially hundreds of lines) gets flagged as dead code.
This could, for example, cause IDEs to add error squiggly's to the whole
function.
By using the span from the ident instead, we narrow the scope of this in
most cases. In a wider sense, it's probably safe to use ident.span
instead of def_span in most locations throughout the whole code base,
but since this is my first contribution, I kept it small.
Some interesting points that came up while I was working on this:
- I reorganized the tests a bit to bring some of the dead code ones all
into the same location
- A few tests were for things unrelated to dead code (like the
path-lookahead for parens), so I added #![allow(dead_code)] and
cleaned up the stderr file to reduce noise in the future
- The same fix doesn't apply to const and static declarations. I tried
adding these cases to the match expression, but that created a much
wider change to tests and error messages, so I left it off until I
could get some code review to validate the approach.
Rollup of 9 pull requests
Successful merges:
- #65776 (Rename `LocalInternedString` and more)
- #65973 (caller_location: point to macro invocation sites, like file!/line!, and use in core::panic!.)
- #66015 (librustc_lexer: Refactor the module)
- #66062 (Configure LLVM module PIC level)
- #66086 (bump smallvec to 1.0)
- #66092 (Use KERN_ARND syscall for random numbers on NetBSD, same as FreeBSD.)
- #66103 (Add target thumbv7neon-unknown-linux-musleabihf)
- #66133 (Update the bundled `wasi-libc` repository)
- #66139 (use American spelling for `pluralize!`)
Failed merges:
r? @ghost
Update the bundled `wasi-libc` repository
This updates the libc that the `wasm32-wasi` target links against to the
latest revision, mostly just bringing in minor bug fixes and minor wasm
size improvements.
Add target thumbv7neon-unknown-linux-musleabihf
This is a copy of thumbv7neon-unknown-linux-gnueabihf with musl changes
merged from armv7-unknown-linux-musleabihf. This appears to have been
missed when adding the other ARMv7-A thumb targets.
Use KERN_ARND syscall for random numbers on NetBSD, same as FreeBSD.
This system call is present on all supported NetBSD versions and provides an endless stream of non-blocking random data from the kernel's ChaCha20-based CSPRNG. It doesn't require a file like `/dev/urandom` to be opened.
The system call is documented here (under kern.arandom):
https://netbsd.gw.com/cgi-bin/man-cgi?sysctl+7+NetBSD-7.0
And defined here:
https://nxr.netbsd.org/xref/src/sys/sys/sysctl.h#273
The semantics are the same as FreeBSD so reading 256 bytes per call is fine.
Similar change for getrandom crate: rust-random/getrandom#115
Configure LLVM module PIC level
As of LLVM 9, this is required for 32-bit PowerPC to properly generate
PLT references. Previously, only BigPIC was supported; now LLVM supports
both BigPIC and SmallPIC, and there is no default value provided.
librustc_lexer: Refactor the module
This PR introduces a refactoring of the `librustc_lexer` in order to improve readability.
All the changes performed are only cosmetic and do not introduce any changes the lexer logic or performance.
Newly introduced modules `literal`, `token` and `utils` are just copy-pasted from the `lib.rs` and do not contain even cosmetic changes (I decided to do so so it'll be easier to review changes looking only on diff).
r? @petrochenkov
cc @Centril @matklad
caller_location: point to macro invocation sites, like file!/line!, and use in core::panic!.
The main change here is to `core::panic!`, trying to fix this remaining regression: https://github.com/rust-lang/rust/pull/65927#issuecomment-547625147
However, in order for `caller_location` to be usable from macros the same way `file!()`/`line!()` are, it needs to have the same behavior (of extracting the macro invocation site `Span` and using that).
Arguably we would've had to do this at some point anyway, if we want to use `#[track_caller]` to replace the `file!()`/`line!()` uses from macros, but I'm not sure the RFC mentions this at all.
r? @petrochenkov cc @anp @nnethercote
Rename `LocalInternedString` and more
This PR renames `LocalInternedString` as `SymbolStr`, removes an unnecessary `impl` from it, improves comments, and cleans up some `SymbolStr` uses.
r? @estebank
Rollup of 11 pull requests
Successful merges:
- #65892 (Remove `PartialEq` and `Eq` from the `SpecialDerives`.)
- #66014 (Show type parameter name and definition in type mismatch error messages )
- #66027 (Move has_panic_handler to query)
- #66054 (syntax: Avoid span arithmetic for delimiter tokens)
- #66068 (use silent emitter for rustdoc highlighting pass)
- #66081 (let caller of check_ptr_access_align control the error message)
- #66093 (Do not ICE with a precision flag in formatting str and no format arguments)
- #66098 (Detect `::` -> `:` typo when involving turbofish)
- #66101 (Tweak type mismatch caused by break on tail expr)
- #66106 (Fix typo in explanation of `E0080`)
- #66115 (rustc: remove "GlobalMetaData" dead code from hir::map::definitions.)
Failed merges:
r? @ghost
rustc: remove "GlobalMetaData" dead code from hir::map::definitions.
Spotted while refactoring uses of `DefIndex` and/or `LocalDefId`.
r? @michaelwoerister
Tweak type mismatch caused by break on tail expr
When `break;` has a type mismatch because the `Destination` points at a tail
expression with an obligation flowing from a return type, point at the
return type.
Fix#39968.
syntax: Avoid span arithmetic for delimiter tokens
The +/-1 logic is from the time where the whole group had a single span and the delimiter spans had to be calculated from it.
Now the delimiters have their own spans which are constructed by lexer or proc macro API and can be used directly.
If those spans are not perfect, then it should be fixed by tweaking the corresponding lexer logic rather than by trying to add or substract `1` from the span boundaries.
Fixes https://github.com/rust-lang/rust/issues/62524
r? @estebank
Move has_panic_handler to query
Moves us off of a global Once instead re-querying the lang item each time. The conditions on when we set it to true change a little (previously we'd make sure a few more lang items were `Some`) but I think they in practice don't matter, we won't compile later on if we don't have them.
Remove `PartialEq` and `Eq` from the `SpecialDerives`.
Now that PR #65519 landed, this is the follow-on work of removing `PartialEq` and `Eq` from the set of `SpecialDerives` .
When `break;` has a type mismatch because the `Destination` points at a tail
expression with an obligation flowing from a return type, point at the
return type.
Fix#39968.
This updates the libc that the `wasm32-wasi` target links against to the
latest revision, mostly just bringing in minor bug fixes and minor wasm
size improvements.
If item.span is part of a macro invocation, this has several downstream
implications. To name two that were found while working on this:
- The dead-code error gets annotated with a "in this macro invocation"
- Some errors get canceled if they refer to remote crates
Ideally, we should annotate item.ident.span with the same macro info,
but this is a larger change (see: #66095), so for now we just fall
back to the old behavior if this item was generated by a macro.
I use span.macro_backtrace().len() to detect if it's part of a macro,
because that (among other things) is what is used by the code which
adds the "in this macro invocation" annotations mentioned above.
clean highlightSourceLines code
This is the first part of https://github.com/rust-lang/rust/issues/66046. Now that I've splitted the hashchange stuff and the source code lines highlighting, I'll be able to fix the whole issue once and for all.
r? @kinnison
Don't double-count `simd_shuffle` promotion candidates
Resolves#66016.
The `#[rustc_args_required_const]` attribute was added to `simd_shuffle*` in rust-lang/stdarch#825. This caused `promote_consts` to double-count its second argument when recording promotion candidates, which caused the promotion candidate compatibility check to fail.
Once `stdarch` is updated in-tree to include rust-lang/stdarch#825, all special logic around `simd_shuffle` can and should be removed.
Allow specifying LLVM's MCTargetOptions::ABIName in target specification files
This addresses #65024, as it allows RISC-V target specification files to set `"llvm-abiname": "lp64d"`.
Other languages (read: C) usually expose this codegen parameter under a compiler argument like `-mabi=<XYZ>`.
Improve MaybeUninit::get_{ref,mut} documentation
As mentioned in https://github.com/rust-lang/rust/issues/63568#issuecomment-544106668, `MaybeUninit`'s `get_{ref,mut}` documentation is lacking, so this PR attempts to fix that.
That being said, and as @RalfJung mentions in that thread,
> In particular, we should clarify that all the UB rules for these methods equally apply when calling the raw ptr methods and creating a reference manually.
these other docs also need to be improved, which I can do in this PR ~~(hence the `[WIP]`)~~.
Finally, since all these documentations are related to clearly establishing when dealing with uninitialized memory which patterns are known to be sound and which patterns are currently UB (that is, until, if ever, the rules around references to unintialized integers get relaxed, this documentation will treat them as UB, and advise against such patterns (_e.g._, it is not possible to use uninitialized buffers with the `Read` API)), I think that adding even more examples to the main documentation of `MaybeUninit` inherent definition wouldn't hurt either.
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