Warn about ignored generic bounds in `for`
This adds a new lint to fix#42181. For consistency and to avoid code duplication, I also moved the existing "bounds in type aliases are ignored" here.
Questions to the reviewer:
* Is it okay to just remove a diagnostic error code like this? Should I instead keep the warning about type aliases where it is? The old code provided a detailed explanation of what's going on when asked, that information is now lost. On the other hand, `span_warn!` seems deprecated (after this patch, it has exactly one user left!).
* Did I miss any syntactic construct that can appear as `for` in the surface syntax? I covered function types (`for<'a> fn(...)`), generic traits (`for <'a> Fn(...)`, can appear both as bounds as as trait objects) and bounds (`for<'a> F: ...`).
* For the sake of backwards compatibility, this adds a warning, not an error. @nikomatsakis suggested an error in https://github.com/rust-lang/rust/issues/42181#issuecomment-306924389, but I feel that can only happen in a new epoch -- right?
Cc @eddyb
Since #47964 was merged, 64-bit mips started passing all structures
using 64-bit chunks regardless of their contents. The
repr-transparent-aggregates tests needs updating to cope with this.
Modify part of `column!` documentation.
Just like `line!` documentation, I've replaced:
> The returned column is not the invocation of the `column!` macro itself
By
> The returned column is *not necessarily* the line of the `column!` invocation itself
See #46997.
Modify part of `line!` documentation.
In accordance with #46997, I've replaced:
> The returned line is not the invocation of the line! macro itself [...]
By
> The returned line is *not necessarily* the line of the `line!` invocation itself [...]
rustc: Migrate to `termcolor` crate from `term`
This crate moves the compiler's error reporting to using the `termcolor` crate
from crates.io. Previously rustc used a super-old version of the `term` crate
in-tree which is basically unmaintained at this point, but Cargo has been using
`termcolor` for some time now and tools like `rg` are using `termcolor` as well,
so it seems like a good strategy to take!
Note that the `term` crate remains in-tree for libtest. Changing libtest will be
a bit tricky due to how the build works, but we can always tackle that later.
cc #45728
in which parentheses are suggested for should-have-been-tuple-patterns
Programmers used to working in some other languages (such as Python or
Go) might expect to be able to destructure values with comma-separated
identifiers but no parentheses on the left side of an assignment.
Previously, the first name in such code would get parsed as a
single-indentifier pattern—recognizing, for example, the
`let a` in `let a, b = (1, 2);`—whereupon we would have a fatal syntax
error on seeing an unexpected comma rather than the expected semicolon
(all the way nearer to the end of `parse_full_stmt`).
Instead, let's look for that comma when parsing the pattern, and if we
see it, make-believe that we're parsing the remaining elements in a
tuple pattern, so that we can suggest wrapping it all in parentheses. We
need to do this in a separate wrapper method called on a "top-level"
pattern, rather than within
`parse_pat` itself, because `parse_pat` gets called recursively to parse
the sub-patterns within a tuple pattern.
~~We could also do this for `match` arms, `if let`, and `while let`, but
we elect not to in this patch, as it seems less likely for users to make
the mistake in those contexts.~~
Resolves#48492.
r? @petrochenkov
Just like `line!` documentation, I've replaced:
> The returned column is not the invocation of the `column!` macro itself
By
> The returned column is *not necessarily* the line of the `column!` invocation itself
See #46997.
In accordance with #46997, I've replaced:
> The returned line is not the invocation of the line! macro itself [...]
By
> The returned line is *not necessarily* the line of the `line!` invocation itself [...]
Programmers used to working in some other languages (such as Python or
Go) might expect to be able to destructure values with comma-separated
identifiers but no parentheses on the left side of an assignment.
Previously, the first name in such code would get parsed as a
single-indentifier pattern—recognizing, for example, the
`let a` in `let a, b = (1, 2);`—whereupon we would have a fatal syntax
error on seeing an unexpected comma rather than the expected semicolon
(all the way nearer to the end of `parse_full_stmt`).
Instead, let's look for that comma when parsing the pattern, and if we
see it, momentarily make-believe that we're parsing the remaining
elements in a tuple pattern, so that we can suggest wrapping it all in
parentheses. We need to do this in a separate wrapper method called on
the top-level pattern (or `|`-patterns) in a `let` statement, `for`
loop, `if`- or `while let` expression, or match arm rather than within
`parse_pat` itself, because `parse_pat` gets called recursively to parse
the sub-patterns within a tuple pattern.
Resolves#48492.
rustc: Fix ICE with `#[target_feature]` on module
This commit fixes an ICE in rustc when `#[target_feature]` was applied to items
other than functions due to the way the feature was validated.
Add a potential cause raising `ParseIntError`.
Initially, I wanted to add it directly to the documentation of `str. parse()` method, I finally found that it was more relevant (I hope so?) to directly document the structure in question. I've added a scenario, in which we could all get caught at least once, to make it easier to diagnose the problem when parsing integers.
Replace iterator structures with `impl Trait`.
Two commits:
* Replace iterator structures with `impl Trait`.
* Run rustfmt on `src/librustc_data_structures/graph/mod.rs`.
