Generalize diagnostic for `x = y` where `bool` is the expected type
Extracted out of https://github.com/rust-lang/rust/pull/59288.
Currently we special case a diagnostic for `if x = y { ...` since the expected type is `bool` in this case and we instead suggest `if x == y`. This PR generalizes this such that given an expression of form `x = y` (`ExprKind::Assign(..)`) where the expected type is `bool`, we emit a suggestion `x == y`.
r? @oli-obk
Let's do a perf run to make sure this was not the source of regressions in #59288.
Introduce proc_macro::Span::source_text
A function to extract the actual source behind a Span.
Background: I would like to use `syn` in a `build.rs` script to parse the rust code, and extract part of the source code. However, `syn` only gives access to proc_macro2::Span, and i would like to get the source code behind that.
I opened an issue on proc_macro2 bug tracker for this feature https://github.com/alexcrichton/proc-macro2/issues/110 and @alexcrichton said the feature should first go upstream in proc_macro. So there it is!
Since most of the Span API is unstable anyway, this is guarded by the same `proc_macro_span` feature as everything else.
Provide suggestion when using field access instead of path
When trying to access an associated constant as if it were a field of
an instance, provide a suggestion for the correct syntax.
Fix#57316.
filter suggestions from extern prelude
Fixes#59027.
Modifies the candidate gathering code to call `filter_fn` on extern crates, which causes them to be filtered out when looking for a type.
make asm diagnostic instruction optional
`DiagnosticInfoInlineAsm::getInstruction` may return a null pointer, so
the instruction shouldn't be blindly unwrapped.
Reopening from #55193. I was unable to trigger the assertion on Windows after rebasing.
Fixes#23458.
Fixes#55216.
When moving out of a for loop head, suggest borrowing it
When encountering code like the following, suggest borrowing the for loop
head to avoid moving it into the for loop pattern:
```
fn main() {
let a = vec![1, 2, 3];
for i in &a {
for j in a {
println!("{} * {} = {}", i, j, i * j);
}
}
}
```
Fix#25534.
When encountering code like the following, suggest borrowing the for loop
head to avoid moving it into the for loop pattern:
```
fn main() {
let a = vec![1, 2, 3];
for i in &a {
for j in a {
println!("{} * {} = {}", i, j, i * j);
}
}
}
```
Rollup of 7 pull requests
Successful merges:
- #59213 (Track changes to robots.txt)
- #59239 (Remove inline assembly from hint::spin_loop)
- #59251 (Use a valid name for graphviz graphs)
- #59296 (Do not encode gensymed imports in metadata)
- #59328 (Implement specialized nth_back() for Box and Windows.)
- #59355 (Fix ICE with const generic param in struct)
- #59377 (Correct minimum system LLVM version in tests)
Correct minimum system LLVM version in tests
Since commit 9452a8dfa3, the new debug info format is only generated
for LLVM 8 and newer versions. However, the tests still assume that LLVM
7 will use the new debug info format. Fix the tests (and a comment in
the code) to match the actual version check.
(WIP) Small fixes in chalkification
Small fixes around region constraints and builtin impls. There are still some type inference errors, for example the following code errors out:
```rust
fn main() {
let mut x: Vec<i32> = Vec::new();
// ^^^^^^^^ cannot infer type for `std::vec::Vec<_>`
}
```
but explicitly specifying `Vec::<i32>::new` works.
With these few fixes, the following code now passes type-checking:
```rust
fn main() {
let mut x: Vec<i32> = Vec::<i32>::new();
x.push(5);
println!("{:?}", x);
}
```
I also fixed the implied bounds bug as discussed on Zulip and in https://github.com/rust-lang-nursery/chalk/pull/206
cc @tmandry
r? @nikomatsakis
Do not encode gensymed imports in metadata
(Unless they are underscore `_` imports which are re-gensymed on crate loading, see https://github.com/rust-lang/rust/pull/56392.)
We cannot encode gensymed imports properly in metadata and if we encode them improperly, we can get erroneous name conflicts downstream.
Gensymed imports are produced by the compiler, so we control their set, and can be sure that none of them needs being encoded for use from other crates.
A workaround that fixes https://github.com/rust-lang/rust/issues/59243.
Use a valid name for graphviz graphs
Hiridification has broken graphviz output because `HirId` has a more complex display implemetation than `NodeId`. Since the id was just used to generate a distinct identifier, we just pull out the various constituent indexed.
This commit makes two changes - separating the `NodeId` that identifies
an enum variant from the `NodeId` that identifies the variant's
constructor; and no longer creating a `NodeId` for `Struct`-style enum
variants and structs.
Separation of the variant id and variant constructor id will allow the
rest of RFC 2008 to be implemented by lowering the visibility of the
variant's constructor without lowering the visbility of the variant
itself.
No longer creating a `NodeId` for `Struct`-style enum variants and
structs mostly simplifies logic as previously this `NodeId` wasn't used.
There were various cases where the `NodeId` wouldn't be used unless
there was an unit or tuple struct or enum variant but not all uses of
this `NodeId` had that condition, by removing this `NodeId`, this must
be explicitly dealt with. This change mostly applied cleanly, but there
were one or two cases in name resolution and one case in type check
where the existing logic required a id for `Struct`-style enum variants
and structs.
Remove `track_errors` from `check_match`, `typeck_item_bodies` and `register_plugins`
In the spirit of continuing through errors in type checking (#39275), remove `track_errors` from a couple of locations in the codebase.
