Consolidate two almost duplicated fn info extraction routines
Moves `extract_callable_info` up to trait selection, because it was being (almost) duplicated fully there for similar diagnostic purposes. This also generalizes the diagnostics we can give slightly (see UI test).
Suggestion for type mismatch when we need a u8 but the programmer wrote a char literal
Today Rust just points out that we have a char and we need a u8, but if I wrote 'A' then I could fix this by just writing b'A' instead. This code should detect the case where we're about to report a type mismatch of this kind, and the programmer wrote a char literal, and the char they wrote is ASCII, so therefore just prefixing b to make a byte literal will do what they meant.
I have definitely written this mistake more than once, it's not difficult to figure out what to do, but the compiler might as well tell us anyway.
I provided a test with two simple examples where the suggestion is appropriate, and one where it is not because the char literal is not ASCII, showing that the suggestion is only triggered in the former cases.
I have contributed only a small typo doc fix before, so this is my first substantive rustc change.
rustdoc: remove `docblock` class from notable trait popover
This commit builds on b72de9be74dd5ac1d8b23d5ece03a7690274a14c, which removes the `docblock` class from the All Items page, and 9457380ac902db3febf92077c5b645db55998ad4, which removes the `docblock` class from the item decl.
Fixes#92974
Emit a hint for bad call return types due to generic arguments
When the return type of a function call depends on the type of an argument, e.g.
```
fn foo<T>(x: T) -> T {
x
}
```
and the expected type is set due to either an explicitly typed binding, or because the call to the function is in a tail position without semicolon, the current error implies that the argument in the call has the wrong type.
This new hint highlights that the expected type doesn't match the returned type, which matches the argument type, and that that's why we're flagging the argument type.
Fixes#43608.
Add note when `FnPtr` vs. `FnDef` impl trait
I encountered an instance where an `FnPtr` implemented a trait, but I was passing an `FnDef`. I was confused for an hour and to examine the source code of the trait's crate's tests in order to understand how to cast it properly (it didn't help that it was behind a reference). To the end user, it might not be immediately obvious that they are different and how to convert from an `FnDef` to an `FnPtr`, but it is necessary to cast to the generic function in order to compile. It is thus useful to suggest `as` in the help note, (even if the `Fn` output implements the trait).
Emit a single error for contiguous sequences of unknown tokens
Closes#106101
On encountering a sequence of identical source characters which are unknown tokens, note the amount of subsequent characters and advance past them silently. The old behavior was to emit an error and 'help' note for every single one.
`@rustbot` label +A-diagnostics +A-parser
Fix mir-opt tests for big-endian platforms
The test cases src/test/mir-opt/building/custom/consts.rs and src/test/mir-opt/const_prop/mutable_variable_no_prop.rs are currently failing on big-endian platforms as the binary encoding of some constants is hard-coded in the MIR test files. Fix this by choosing constant values that have the same encoding on big- and little-endian platforms.
The test case src/test/mir-opt/issues/issue_75439.rs is failing as well, but since the purpose of the test is to validate handling of big-endian integer encodings on a little-endian platform, it does not make much sense to run it on big-endian platforms in the first place - we can just ignore it there.
Fixed part of https://github.com/rust-lang/rust/issues/105383.
I encountered an instance where an `FnPtr` implemented a trait, but I was passing an `FnDef`. To
the end user, there is really no way to differentiate each of them, but it is necessary to cast
to the generic function in order to compile. It is thus useful to suggest `as` in the help note,
(even if the Fn output implements the trait).
rustdoc: remove unnecessary DOM class `h1.fqn`
It's misleading. The main heading sometimes isn't an fully qualified name at all.
It's also redundant. It's always a child of `div.main-heading`, so just use that.
Update `rental` hack to work with remapped paths.
This PR simply switches to an already-existing helper instead of hard-coding a specific enum variant. The new revision of the test fails without the other changes in this PR.
Context: I'm exploring running UI tests with remapped paths by default in #105924 and the rental test was one of the ones that failed.
This may also be useful in the context of https://github.com/rust-lang/rfcs/pull/3127 ("New rustc and Cargo options to allow path sanitisation by default").
rustdoc: rename CSS rustdoc-toggle -> toggle and toggle -> settings-toggle
This swaps things around so that the class that gets used more often has the shorter name.
This commit builds on b72de9be74dd5ac1d8b23d5ece03a7690274a14c, which removes
the `docblock` class from the All Items page, and
9457380ac902db3febf92077c5b645db55998ad4, which removes the `docblock` class
from the item decl.
Fixes#92974
Normalize test output more thoroughly
This prevents differences in local environments, which may (for example) end up with a longer backtrace with more digits in the backtrace prefix, as happened to me. While we're at it, clean more of the output up, including the exact location of the error in the compiler.
cc https://github.com/rust-lang/rust/pull/106521 which introduced this test
Warn when using panic-strategy abort for proc-macro crates
See https://github.com/rust-lang/rust/issues/82320, this simply warns for now as that seems like the best step that can be immediately taken (opposed to straight up rejecting or ignoring)
Bump `IMPLIED_BOUNDS_ENTAILMENT` to Deny + ReportNow
https://github.com/rust-lang/rust/pull/105575#issuecomment-1357201969
> and then later in the same cycle increase the lint to `deny` and change it to `FutureCompatReportNow` in this nightly cycle.
r? ```@lcnr``` when they're back from holiday 😄
Add log-backtrace option to show backtraces along with logging
according to #90698, I added a compiler option, `-Zlog-backtrace=filter`, where `filter` is a module name, to show backtraces for logging without rebuilding.
resolve#90698
It's misleading. The main heading sometimes isn't an fully qualified name at all.
It's also redundant. It's always a child of `div.main-heading`, so just use that.
Render missing generics suggestion verbosely
It's a bit easier to read like this, especially ones that are appending new generics onto an existing list, like ": `, T`" which render somewhat poorly inline.
Also don't suggest `dyn` as a type parameter to add, even if technically that's valid in edition 2015.
When the return type of a function call depends on the type of an
argument, e.g.
```
fn foo<T>(x: T) -> T {
x
}
```
and the expected type is set due to either an explicitly typed
binding, or because the call to the function is in a tail position
without semicolon, the current error implies that the argument in the
call has the wrong type.
This new hint highlights that the expected type doesn't match the
returned type, which matches the argument type, and that that's why
we're flagging the argument type.
Fixes#43608.
