incr.comp.: Enable query result caching for many more queries
Newly cached queries are:
* const_is_rvalue_promotable_to_static
* trans_fulfill_obligation
* optimized_mir
* unsafety_check_result
* borrowck
* mir_borrowck
* mir_const_qualif
* contains_extern_indicator
* def_symbol_name
* symbol_name
This also includes the stricter `Span` hashing first mentioned in #46490, which will lead to more false positives in release builds but overall is more correct -- and necessary for caching MIR. Hopefully we will soon be able to reduce the rate of false positives again by factoring `Span` out of MIR.
r? @nikomatsakis
rustc: Further tweak linkage in ThinLTO
In #46382 the logic around linkage preservation with ThinLTO ws tweaked but the
loop that registered all otherwise exported GUID values as "don't internalize
me please" was erroneously too conservative and only asking "external" linkage
items to not be internalized. Instead we actually want the inversion of that
condition, everything *without* "local" linkage to be internalized.
This commit updates the condition there, adds a test, and...
Closes#46543
In #46382 the logic around linkage preservation with ThinLTO ws tweaked but the
loop that registered all otherwise exported GUID values as "don't internalize
me please" was erroneously too conservative and only asking "external" linkage
items to not be internalized. Instead we actually want the inversion of that
condition, everything *without* "local" linkage to be internalized.
This commit updates the condition there, adds a test, and...
Closes#46543
Stabilize abi_sysv64
Closes#36167, stabilizing the use of the "sysv64" ABI on x64 platforms where it is not the default ABI.
FCP on this is complete in the tracking issue.
MIR borrowck: implement union-and-array-compatible semantics
Fixes#44831.
Fixes#44834.
Fixes#45537.
Fixes#45696 (by implementing DerefPure semantics, which is what we want going forward).
r? @nikomatsakis
coherence: fix is_knowable logic
A trait-ref that passes the orphan-check rules can still be implemented in a crate downstream from our crate (for example, `LocalType for LocalTrait<_>` might be matched by a `LocalType for LocalTrait<TypeFromDownstreamCrate>`), and this should be known by the `is_knowable` logic.
Trait selection had a hackfix for this, but it's an hacky fix that does not handle all cases. This patch removes it.
fixes#43355.
r? @nikomatsakis
Needs a crater run
create a drop ladder for an array if any value is moved out
r? @arielb1
first commit for fix https://github.com/rust-lang/rust/issues/34708 (note: this still handles the subslice case in a very broken manner)
Region inference can create borrows for an empty region if the borrow is
dead. In that case, there's no reason to track the borrow, but because
there's no such thing as an EndRegion(ReEmpty) these borrows used to live
for the entire function.
Fixes#46161.
rustc: Prepare to enable ThinLTO by default
This commit *almost* enables ThinLTO and multiple codegen units in release mode by
default but is blocked on #46346 now before pulling the trigger.
wasm: Update LLVM to fix a test
This commit updates LLVM with some tweaks to the integer <-> floating point
conversion instructions to ensure that `as` in Rust doesn't trap.
Closes#46298
make coercions to `!` in unreachable code a hard error
This was added to cover up a lazy extra semicolon in #35849, but does
not actually make sense. This is removed as a part of the stabilization
of `never_type`.
This commit prepares to enable ThinLTO and multiple codegen units in release
mode by default. We've still got a debuginfo bug or two to sort out before
actually turning it on by default.
This commit updates LLVM with some tweaks to the integer <-> floating point
conversion instructions to ensure that `as` in Rust doesn't trap.
Closes#46298
This was added to cover up a lazy extra semicolon in #35849, but does
not actually make sense. This is removed as a part of the stabilization
of `never_type`.
avoid type-live-for-region obligations on dummy nodes
Type-live-for-region obligations on DUMMY_NODE_ID cause an ICE, and it
turns out that in the few cases they are needed, these obligations are not
needed anyway because they are verified elsewhere.
Fixes#46069.
Beta-nominating because this is a regression for our new beta.
r? @nikomatsakis
This commit allocates a builder to running wasm32 tests on Travis. Not all test
suites pass right now so this is starting out with just the run-pass and the
libcore test suites. This'll hopefully give us a pretty broad set of coverage
for integration in rustc itself as well as a somewhat broad coverage of the llvm
backend itself through integration/unit tests.
Implement the special repr(C)-non-clike-enum layout
This is the second half of https://github.com/rust-lang/rfcs/pull/2195
which specifies that
```rust
#[repr(C, u8)]
#[derive(Copy, Clone, Eq, PartialEq, Debug)]
enum MyEnum {
A(u32), // Single primitive value
B { x: u8, y: i16 }, // Composite, and the offset of `y` depends on tag being internal
C, // Empty
D(Option<u32>), // Contains an enum
E(Duration), // Contains a struct
}
```
Has the same layout as
```rust
#[repr(C)]
struct MyEnumRepr {
tag: MyEnumTag,
payload: MyEnumPayload,
}
#[repr(C)]
#[allow(non_snake_case)]
union MyEnumPayload {
A: MyEnumVariantA,
B: MyEnumVariantB,
D: MyEnumVariantD,
E: MyEnumVariantE,
}
#[repr(u8)] #[derive(Copy, Clone)] enum MyEnumTag { A, B, C, D, E }
#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantA(u32);
#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantB {x: u8, y: i16 }
#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantD(Option<u32>);
#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantE(Duration);
```
Make accesses to fields of packed structs unsafe
To handle packed structs with destructors (which you'll think are a rare
case, but the `#[repr(packed)] struct Packed<T>(T);` pattern is
ever-popular, which requires handling packed structs with destructors to
avoid monomorphization-time errors), drops of subfields of packed
structs should drop a local move of the field instead of the original
one.
That's it, I think I'll use a strategy suggested by @Zoxc, where this mir
```
drop(packed_struct.field)
```
is replaced by
```
tmp0 = packed_struct.field;
drop tmp0
```
cc #27060 - this should deal with that issue after codegen of drop glue
is updated.
The new errors need to be changed to future-compatibility warnings, but
I'll rather do a crater run first with them as errors to assess the
impact.
cc @eddyb
Things which still need to be done for this:
- [ ] - handle `repr(packed)` structs in `derive` the same way I did in `Span`, and use derive there again
- [ ] - implement the "fix packed drops" pass and call it in both the MIR shim and validated MIR pipelines
- [ ] - do a crater run
- [ ] - convert the errors to compatibility warnings
Fix the derive implementation for repr(packed) structs to move the
fields out instead of calling functions on references to each subfield.
That's it, `#[derive(PartialEq)]` on a packed struct now does:
```Rust
fn eq(&self, other: &Self) {
let field_0 = self.0;
let other_field_0 = other.0;
&field_0 == &other_field_0
}
```
Instead of
```Rust
fn eq(&self, other: &Self) {
let ref field_0 = self.0;
let ref other_field_0 = other.0;
&*field_0 == &*other_field_0
}
```
Taking (unaligned) references to each subfield is undefined, unsound and
is an error with MIR effectck, so it had to be prevented. This causes
a borrowck error when a `repr(packed)` struct has a non-Copy field (and
therefore is a [breaking-change]), but I don't see a sound way to avoid
that error.
To handle packed structs with destructors (which you'll think are a rare
case, but the `#[repr(packed)] struct Packed<T>(T);` pattern is
ever-popular, which requires handling packed structs with destructors to
avoid monomorphization-time errors), drops of subfields of packed
structs should drop a local move of the field instead of the original
one.
cc #27060 - this should deal with that issue after codegen of drop glue
is updated.
The new errors need to be changed to future-compatibility warnings, but
I'll rather do a crater run first with them as errors to assess the
impact.
Type-live-for-region obligations on DUMMY_NODE_ID cause an ICE, and it
turns out that in the few cases they are needed, these obligations are not
needed anyway because they are verified elsewhere.
Fixes#46069.
Turns out ThinLTO was internalizing this symbol and eliminating it. Worse yet if
you compiled with LTO turns out no TLS destructors would run on Windows! The
`#[used]` annotation should be a more bulletproof implementation (in the face of
LTO) of preserving this symbol all the way through in LLVM and ensuring it makes
it all the way to the linker which will take care of it.
move closure kind, signature into `ClosureSubsts`
Instead of using side-tables, store the closure-kind and signature in the substitutions themselves. This has two key effects:
- It means that the closure's type changes as inference finds out more things, which is very nice.
- As a result, it avoids the need for the `freshen_closure_like` code (though we still use it for generators).
- It avoids cyclic closures calls.
- These were never meant to be supported, precisely because they make a lot of the fancy inference that we do much more complicated. However, due to an oversight, it was previously possible -- if challenging -- to create a setup where a closure *directly* called itself (see e.g. #21410).
We have to see what the effect of this change is, though. Needs a crater run. Marking as [WIP] until that has been assessed.
r? @arielb1
