DivergingCall is different enough from the regular converging Call to warrant the split. This also
inlines CallData struct and creates a new CallTargets enum in order to have a way to differentiate
between calls that do not have an associated cleanup block.
Note, that this patch still does not produce DivergingCall terminator anywhere. Look for that in
the next patches.
So far, calls going through `Fn::call`, `FnMut::call_mut`, or `FnOnce::call_once` have not been translated properly into MIR:
The call `f(a, b, c)` where `f: Fn(T1, T2, T3)` would end up in MIR as:
```
call `f` with arguments `a`, `b`, `c`
```
What we really want is:
```
call `Fn::call` with arguments `f`, `a`, `b`, `c`
```
This PR transforms these kinds of overloaded calls during `HIR -> HAIR` translation.
What's still a bit funky is that the `Fn` traits expect arguments to be tupled but due to special handling type-checking and trans, we do not actually tuple arguments and everything still checks out fine. So, after this PR we end up with MIR containing calls where function signature and arguments seemingly don't match:
```
call Fn::call(&self, args: (T1, T2, T3)) with arguments `f`, `a`, `b`, `c`
```
instead of
```
call Fn::call(&self, args: (T1, T2, T3)) with arguments `f`, (`a`, `b`, `c`) // <- args tupled!
```
It would be nice if the call traits could go without special handling in MIR and later on.
So far `librustc::trans::base::trans_fn()` and `trans_closure()` have been passed the list of attributes on the function being translated *only* if the function was local and non-generic. For generic functions, functions inlined from other crates, functions with foreign ABI and for closures, only an empty list of attributes was ever passed to `trans_fn()`.
This led to the case that generic functions marked with `#[rustc_mir]` where not actually translated via MIR but via the legacy translation path.
This PR makes function/closure attributes always be passed to `trans_fn()` and disables the one test where this makes a difference.
If there is an actual reason why attributes were not passed along in these cases, let me know.
cc @rust-lang/compiler
cc @luqmana regarding the test case
This moves back (essentially reverts #30265) into MIR-specific translation code, but keeps the
funcition split out, since it is expected to eventually become recursive.
Fixes https://github.com/rust-lang/rust/issues/29572
cc @oli-obk
This PR changes the `emit_opaque` and `read_opaque` methods in the RBML library to use a space-efficient binary encoder that does not emit any tags and uses the LEB128 variable-length integer format for all numbers it emits.
The space savings are nice, albeit a bit underwhelming, especially for dynamic libraries where metadata is already compressed.
| RLIBs | NEW | OLD |
|--------------|--------|-----------|
|libstd | 8.8 MB | 10.5 MB |
|libcore |15.6 MB | 19.7 MB |
|libcollections| 3.7 MB | 4.8 MB |
|librustc |34.0 MB | 37.8 MB |
|libsyntax |28.3 MB | 32.1 MB |
| SOs | NEW | OLD |
|---------------|-----------|--------|
| libstd | 4.8 MB | 5.1 MB |
| librustc | 8.6 MB | 9.2 MB |
| libsyntax | 7.8 MB | 8.4 MB |
At least this should make up for the size increase caused recently by also storing MIR in crate metadata.
Can this be a breaking change for anyone?
cc @rust-lang/compiler
This moves back (essentially reverts #30265) into MIR-specific translation code, but keeps the
funcition split out, since it is expected to eventually become recursive.
`auto_ref()` currently returns an Rvalue datum for the ref'd value,
which is fine for thin pointers, but for fat pointers this means that
once the pointer is moved out of that datum, its memory will be marked
as dead. And because there is not necessarily an intermediate temporary
involved we can end up marking memory as dead that is actually still
used.
As I don't want to break the micro-optimization for thin pointers by
always returning an Lvalue datum, I decided to only do so for fat
pointers.
Fix#30478
`auto_ref()` currently returns an Rvalue datum for the ref'd value,
which is fine for thin pointers, but for fat pointers this means that
once the pointer is moved out of that datum, its memory will be marked
as dead. And because there is not necessarily an intermediate temporary
involved we can end up marking memory as dead that is actually still
used.
As I don't want to break the micro-optimization for thin pointers by
always returning an Lvalue datum, I decided to only do so for fat
pointers.
Fix#30478
This PR is a rebase of the original PR by @eddyb https://github.com/rust-lang/rust/pull/21836 with some unrebasable parts manually reapplied, feature gate added + type equality restriction added as described below.
This implementation is partial because the type equality restriction is applied to all type ascription expressions and not only those in lvalue contexts. Thus, all difficulties with detection of these contexts and translation of coercions having effect in runtime are avoided.
So, you can't write things with coercions like `let slice = &[1, 2, 3]: &[u8];`. It obviously makes type ascription less useful than it should be, but it's still much more useful than not having type ascription at all.
In particular, things like `let v = something.iter().collect(): Vec<_>;` and `let u = t.into(): U;` work as expected and I'm pretty happy with these improvements alone.
Part of https://github.com/rust-lang/rust/issues/23416
