First some background:
To the compiler, the following two signatures in the trait vs the impl
are the same.
```rust
trait Foo {
fn foo(&self, &impl Debug);
}
impl Foo for () {
fn foo<U: Debug>(&self, x: &U) { ... }
}
```
We do not want to allow this, and so we add a new error and check.
The check just tests that all paramters 'syntheticness' match up. As
during collection, the impl Trait parameters are transformed into
anonymous synthetic generics.
Furthermore, causes a check for unused type parameters to be skipped in
check_bounds_are_used if there is already a TyError. Thus, an unused
input will not trigger `type parameter unused` errors.
Update the one test that checked for this error in the case of
a TyError.
In ast_generics extraction in generics_of and explicit_predicates_of,
also collect inputs if there are any.
Then use a Visitor to extract the necessary information from the
TyImplTraitUniversal types before extending generics and predicates with
the new information.
This is for tracking if an ImplItem is part of a trait impl. Add
a with_trait_impl_ref method to ItemLowerer to appropriately save the
state to allow appropriate nesting of trait and non-trait impls.
Replace hir::TyImplTrait with TyImplTraitUniversal and
TyImplTraitExistential.
Add an ImplTraitContext enum to rustc::hir::lowering to track the kind
and allowedness of an impl Trait.
Significantly alter lowering to thread ImplTraitContext and one other
boolean parameter described below throughought much of lowering.
The other parameter is for tracking if lowering a function is in a trait
impl, as there is not enough information to otherwise know this
information during lowering otherwise.
This change also removes the checks from ast_ty_to_ty for impl trait
allowedness as they are now all taking place in HIR lowering.
Emit better debugging information for a trait object pointer. In
particular, now:
* The fields are explicitly represented in the DWARF;
* DWARF for the vtable itself is emitted; and
* The DWARF for the vtable's type has a DW_AT_containing_type which
points to the concrete type for which the vtable was emitted. This is
a small DWARF extension, that allows debuggers to determine the real
type of the object to which a trait object points.
I'll submit the gdb patch to take advantage of this new debuginfo once
this lands.
The vtable type is not currently complete -- it doesn't include members
for the pointers it contains. This information was not needed for this
feature.
This addresses part 1 of #1563.
This adds a "min-system-llvm-version" directive, so that a test can
indicate that it will either work with rust-llvm or with some minimal
system LLVM. This makes it simpler to write a test that requires an
LLVM patch that landed upstream and was then backported to rust-llvm.
rustc_driver: expose a way to override query providers in CompileController.
This API has been a long-time coming and will probably become the main method for custom drivers (that is, binaries other than `rustc` itself that use `librustc_driver`) to adapt the compiler's behavior.
always add an unreachable branch on matches to give more info to llvm
As part of https://github.com/djzin/rustc-optimization I discovered that some simple enum optimizations (src/unary/three_valued_enum.rs and src/unary/four_valued_enum.rs in the repo) are not applied - and the reason for this is that we erase the info that the discriminant of an enum is one of the options by putting the last one in an "otherwise" branch. This patch adds an extra branch so that LLVM can know what the possibilities are for the discriminant, which fixes the three- and four- valued cases.
Note that for whatever reason, this doesn't fix the case of 2 variants (most notably `Option` and `Result` have 2 variants) - a pass re-ordering might fix this or we may wish to add "assume" annotations on discriminants to force it to optimize.
MIR-borrowck: don't ICE for cannot move from array error
Closes#45694
compile-fail test E0508 now gives
```text
error[E0508]: cannot move out of type `[NonCopy; 1]`, a non-copy array (Ast)
--> .\src\test\compile-fail\E0508.rs:18:18
|
18 | let _value = array[0]; //[ast]~ ERROR E0508
| ^^^^^^^^
| |
| cannot move out of here
| help: consider using a reference instead: `&array[0]`
error[E0508]: cannot move out of type `[NonCopy; 1]`, a non-copy array (Mir)
--> .\src\test\compile-fail\E0508.rs:18:18
|
18 | let _value = array[0]; //[ast]~ ERROR E0508
| ^^^^^^^^ cannot move out of here
error: aborting due to 2 previous errors
```
Use #!/usr/bin/env as shebang for Bash scripts
On some systems, the bash command could be available in another
directory than /bin. As such, to offer an env shebang is more
convenient.
This make sense even for docker scripts, as you can use Docker
on FreeBSD or SmartOS for example.
update match-expressions.rs with DepNode labels
As a part of #44924, I have updated the match-expressions.rs. The PR has tests verified for the following dependency nodes for let-expressions
- MirValidated
- MirOptimized
- TypeCheckTables
- TypeOfItem
- GenericsOfItem
- PredicatesOfItem
- FnSignature
cc @michaelwoerister
r? @nikomatsakis
Niko Matsakis
Christopher Vittal
bors
Laurentiu Nicola
Guillaume Gomez
Michael Woerister
Oliver Schneider
Mikhail Modin
Tom Tromey
QuietMisdreavus
Michael Lamparski
Ramana Venkata
gnzlbg
Jeff Crocker
Ariel Ben-Yehuda
