Setup two tasks, one of which only processes the signatures, in order to
isolate the typeck entries for signatures from those for bodies.
Fixes#36078Fixes#37720
This used to work with the rustc_clean attribute, but doesn't anymore
since my rebase; but I don't know enough about the type checking to find
out what's wrong. The dep graph looks like this:
ItemSignature(xxxx) -> CollectItem(xxxx)
CollectItem(xxxx) -> ItemSignature(xxxx)
ItemSignature(xxxx) -> TypeckItemBody(yyyy)
HirBody(xxxx) -> CollectItem(xxxx)
The cycle between CollectItem and ItemSignature looks wrong, and my
guess is the CollectItem -> ItemSignature edge shouldn't be there, but
I'm not sure how to prevent it.
Fix rustbuild on 32 bit Linux
This is cherry-picked from #37817 which seems to be stalled and currently needs to be rebased anyway.
r? @alexcrichton (who authored this change)
For a given file
```
trait Foo {
fn bar(&self);
}
pub struct FooConstForMethod;
impl Foo for FooConstForMethod {
const bar: u64 = 1;
}
```
show
```
error[E0323]: item `bar` is an associated const, which doesn't match its trait `Foo`
```
instead of
```
error[E0323]: item `bar` is an associated const, which doesn't match its trait `<FooConstForMethod as Foo>`
```
This is an annoying gotcha with the projection cache's handling of
nested obligations.
Nested projection obligations enter the issue in this case:
```
DEBUG:rustc::traits::project: AssociatedTypeNormalizer: depth=3
normalized
<std::iter::Map<std::ops::Range<i32>,
[closure@not-a-recursion-error.rs:5:30: 5:53]> as
std::iter::IntoIterator>::Item to _#7t with 12 add'l obligations
```
Here the normalization result is the result of the nested impl
`<[closure@not-a-recursion-error.rs:5:30: 5:53] as FnMut(i32)>::Output`,
which is an additional obligation that is a part of "add'l obligations".
By itself, this is proper behaviour - the additional obligation is
returned, and the RFC 447 rules ensure that it is processed before the
output `#_7t` is used in any way.
However, the projection cache breaks this - it caches the
`<std::iter::Map<std::ops::Range<i32>,[closure@not-a-recursion-error.rs:5:30:
5:53]> as std::iter::IntoIterator>::Item = #_7t` resolution. Now
everybody else that attempts to look up the projection will just get
`#_7t` *without* any additional obligations. This obviously causes all
sorts of trouble (here a spurious `EvaluatedToAmbig` results in
specializations not being discarded
[here](9ca50bd4d5/src/librustc/traits/select.rs (L1705))).
The compiler works even with this projection cache gotcha because in most
cases during "one-pass evaluation". we tend to process obligations in LIFO
order - after an obligation is added to the cache, we process its nested
obligations before we do anything else (and if we have a cycle, we handle
it specifically) - which makes sure the inference variables are resolved
before they are used.
That "LIFO" order That was not done when projecting out of a closure, so
let's just fix that for the time being.
Fixes#38033.
Previously the `LineWriter` could successfully write some bytes but then fail to
report that it has done so. Additionally, an erroneous flush after a successful
write was permanently ignored. This commit fixes these two issues by (a)
maintaining a `need_flush` flag to indicate whether a flush should be the first
operation in `LineWriter::write` and (b) avoiding returning an error once some
bytes have been successfully written.
Closes#37807
Support `?Sized` in where clauses
Implemented as described in https://github.com/rust-lang/rust/issues/20503#issuecomment-258677026 - `?Trait` bounds are moved on type parameter definitions when possible, reported as errors otherwise.
(It'd be nice to unify bounds and where clauses in HIR, but this is mostly blocked by rustdoc now - it needs to render bounds in pleasant way and the best way to do it so far is to mirror what was written in source code.)
Fixes https://github.com/rust-lang/rust/issues/20503
r? @nikomatsakis
StringRefs have a length and their contents are not usually null-terminated.
The solution is to either copy the string data (in rustc_llvm::diagnostic) or take the size into account (in LLVMRustPrintPasses).
I couldn't trigger a bug caused by this (apparently all the strings returned in practice are actually null-terminated) but this is more correct and more future-proof.
