The Great Generics Generalisation: Ty Edition
Part of the generic parameter refactoring effort, split off from https://github.com/rust-lang/rust/pull/48149. Contains the `ty`-relative refactoring.
r? @eddyb
Improve eager type resolution error message
This PR improves the span of eager resolution type errors referring to indexing and field access to use the base span rather than the whole expression.
Also a "note: type must be known at this point" is added where in the past we emitted the "type must be known at this context" error, so that early failures can be differentiated and will hopefully be less surprising.
Fixes#50692 (or at least does the best we can for the moment)
r? @estebank
This PR improves the span of eager resolution type errors referring to indexing and field access to use the base span rather than the whole expression.
Also a note "Type must be known at this point." is added to where we at some point in the past emitted the "type must be known at this context" error, so that early failures can be differentiated and will hopefully be less surprising.
Fixes#50692 (or at least does the best we can for the moment)
r? @estebank
Rollup of 8 pull requests
Successful merges:
- #50624 (fs::write: Add example writing a &str)
- #50634 (Do not silently truncate offsets for `read_at`/`write_at` on emscripten)
- #50644 (AppVeyor: Read back trace from crash dump on failure.)
- #50661 (Ignore non .rs files for tidy libcoretest)
- #50663 (rustc: Allow an edition's feature on that edition)
- #50667 (rustc: Only suggest deleting `extern crate` if it works)
- #50670 (rustc: Include semicolon when removing `extern crate`)
- #50678 (Update openbsd targets)
Failed merges:
rustc: Include semicolon when removing `extern crate`
Currently the lint for removing `extern crate` suggests removing `extern crate`
most of the time, but the rest of the time it suggest replacing it with `use
crate_name`. Unfortunately though when spliced into the original code you're
replacing
extern crate foo;
with
use foo
which is syntactically invalid! This commit ensure that the trailing semicolon
is included in rustc's suggestion to ensure that the code continues to compile
afterwards.
typeck: Fix ICE with struct update syntax
If check_expr_struct_fields fails, do not continue to record update.
If we continue to record update, the struct may cause us to ICE later
on indexing a field that may or may not exist.
Fixes: #50618
Better error reporting in Copy derive
In Copy derive, report all fulfillment erros when present and do not report errors for types tainted with `TyErr`. Also report all fields which are not Copy rather than just the first.
Also refactored `fn fully_normalize`, removing the not very useful helper function along with a FIXME to the closed issue #26721 that looks out of context now.
Fixes#50480
r? @estebank
In Copy derive, report all fulfillment erros when present and do not
report errors for types tainted with `TyErr`. Also report all fields
which are not Copy rather than just the first.
Also refactored `fn fully_normalize`, removing the not very useful
helper function along with a FIXME to the closed issue #26721 that's
looks out of context now.
don't make crazy suggestion for unreachable braced pub-use
The Higher Intermediate Representation doesn't have spans for visibility
keywords, so we were assuming that the first whitespace-delimited token
in the item span was the `pub` to be weakened. This doesn't work for
brace-grouped `use`s, which get lowered as if they were several
individual `use` statements, but with spans that only cover the braced
path-segments. Constructing a correct suggestion here presents some
challenges—until someone works those out, we can at least protect the
dignity of our compiler by not offering any suggestion at all for `use` items.
This resolves#50455 (but again, it would be desirable in the future to
make a correct suggestion instead of copping out like this).
r? @Manishearth
If check_expr_struct_fields fails, do not continue to record update.
If we continue to record update, the struct may cause us to ICE later
on indexing a field that may or may not exist.
Currently the lint for removing `extern crate` suggests removing `extern crate`
most of the time, but the rest of the time it suggest replacing it with `use
crate_name`. Unfortunately though when spliced into the original code you're
replacing
extern crate foo;
with
use foo
which is syntactically invalid! This commit ensure that the trailing semicolon
is included in rustc's suggestion to ensure that the code continues to compile
afterwards.
The Higher Intermediate Representation doesn't have spans for visibility
keywords, so we were assuming that the first whitespace-delimited token
in the item span was the `pub` to be weakened. This doesn't work for
brace-grouped `use`s, which get lowered as if they were several
individual `use` statements, but with spans that only cover the braced
path-segments. Constructing a correct suggestion here presents some
challenges—until someone works those out, we can at least protect the
dignity of our compiler marking the suggestion for `use` items as
potentially incorrect.
This resolves#50455 (but again, it would be desirable in the future to
make a correct suggestion instead of copping out like this).
Improve single-use and zero-use lifetime lints
The code now correctly identifies *when* to lint -- or more correctly, anyhow -- but it doesn't yet offer suggestions for how to fix.
(I just remembered when writing this I had meant to go back over some of these cases around e.g. impl Trait and double check that everything is right...)
cc #44752
r? @cramertj
This is the first small step towards testing auto-fixable compiler
suggestions using compiletest. Currently, it only checks if next to a
UI test there also happens to a `*.rs.fixed` file, and then uses rustfix
(added as external crate) on the original file, and asserts that it
produces the fixed version.
To show that this works, I've included one such test. I picked this test
case at random (and because it was simple) -- It is not relevant to the
2018 edition. Indeed, in the near future, we want to be able to restrict
rustfix to edition-lints, so this test cast might go away soon.
In case you still think this is somewhat feature-complete, here's a
quick list of things currently missing that I want to add before telling
people they can use this:
- [ ] Make this an actual compiletest mode, with `test [fix] …` output
and everything
- [ ] Assert that fixed files still compile
- [ ] Assert that fixed files produce no (or a known set of) diagnostics
output
- [ ] Update `update-references.sh` to support rustfix
- [ ] Use a published version of rustfix (i.e.: publish a new version
rustfix that exposes a useful API for this)
Rollup of 12 pull requests
Successful merges:
- #50302 (Add query search order check)
- #50320 (Fix invalid path generation in rustdoc search)
- #50349 (Rename "show type declaration" to "show declaration")
- #50360 (Clarify wordings of the `unstable_name_collision` lint.)
- #50365 (Use two vectors in nearest_common_ancestor.)
- #50393 (Allow unaligned reads in constants)
- #50401 (Revert "Implement FromStr for PathBuf")
- #50406 (Forbid constructing empty identifiers from concat_idents)
- #50407 (Always inline simple BytePos and CharPos methods.)
- #50416 (check if the token is a lifetime before parsing)
- #50417 (Update Cargo)
- #50421 (Fix ICE when using a..=b in a closure.)
Failed merges:
Forbid constructing empty identifiers from concat_idents
The empty identifier is a [reserved identifier](8a37c75a3a/src/libsyntax_pos/symbol.rs (L300-L305)) in rust, apparently used for black magicks like representing the crate root or somesuch... and therefore, being able to construct it is Ungood. Presumably.
...even if the macro that lets you construct it is so useless that you can't actually do any damage with it. (and believe me, I tried)
Fixes#50403.
**Note:** I noticed that when you try to do something similar with `proc_macro::Term`, the compiler actually catches it and flags the identifier as reserved. Perhaps a better solution would be to somehow have that same check applied here.
Implement tool_attributes feature (RFC 2103)
cc #44690
This is currently just a rebased and compiling (hopefully) version of #47773.
Let's see if travis likes this. I will add the implementation for `tool_lints` this week.
