The "hint" mechanism is essentially used as a workaround to compute
types for expressions which have not yet been type-checked. This
commit clarifies that usage, and limits the effects to the places
where it is currently necessary.
Fixes#26210.
This commit moves the IR files in the distribution, rust_try.ll,
rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main
distribution. There's a few reasons for this change:
* LLVM changes its IR syntax from time to time, so it's very difficult to
have these files build across many LLVM versions simultaneously. We'll likely
want to retain this ability for quite some time into the future.
* The implementation of these files is closely tied to the compiler and runtime
itself, so it makes sense to fold it into a location which can do more
platform-specific checks for various implementation details (such as MSVC 32
vs 64-bit).
* This removes LLVM as a build-time dependency of the standard library. This may
end up becoming very useful if we move towards building the standard library
with Cargo.
In the immediate future, however, this commit should restore compatibility with
LLVM 3.5 and 3.6.
This commit moves the IR files in the distribution, rust_try.ll,
rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main
distribution. There's a few reasons for this change:
* LLVM changes its IR syntax from time to time, so it's very difficult to
have these files build across many LLVM versions simultaneously. We'll likely
want to retain this ability for quite some time into the future.
* The implementation of these files is closely tied to the compiler and runtime
itself, so it makes sense to fold it into a location which can do more
platform-specific checks for various implementation details (such as MSVC 32
vs 64-bit).
* This removes LLVM as a build-time dependency of the standard library. This may
end up becoming very useful if we move towards building the standard library
with Cargo.
In the immediate future, however, this commit should restore compatibility with
LLVM 3.5 and 3.6.
Per the title. I've linked to the reference at http://doc.rust-lang.org/reference.html#type-parameters-1, but I'm not sure that's such a good link - but there doesn't seem to be a great deal of explanation elsewhere in the reference either...
This also changes how variant values are printed in errors, they are no
longer printed in their parent scope. As far as I can tell, this is
leftover from pre-namespacing of enums.
Closes#17546.
The "hint" mechanism is essentially used as a workaround to compute
types for expressions which have not yet been type-checked. This
commit clarifies that usage, and limits the effects to the places
where it is currently necessary.
Fixes#26210.
Transition to the new object lifetime defaults, replacing the old defaults completely.
r? @pnkfelix
This is a [breaking-change] as specified by [RFC 1156][1156] (though all cases that would break should have been receiving warnings starting in Rust 1.2). Types like `&'a Box<Trait>` (or `&'a Rc<Trait>`, etc) will change from being interpreted as `&'a Box<Trait+'a>` to `&'a Box<Trait+'static>`. To restore the old behavior, write the `+'a` explicitly. For example, the function:
```rust
trait Trait { }
fn foo(x: &Box<Trait>) { ... }
```
would be rewritten as:
```rust
trait Trait { }
fn foo(x: &'a Box<Trait+'a>) { ... }
```
if one wanted to preserve the current typing.
[1156]: https://github.com/rust-lang/rfcs/blob/master/text/1156-adjust-default-object-bounds.md
This also changes how variant values are printed in errors, they are no
longer printed in their parent scope. As far as I can tell, this is
leftover from pre-namespacing of enums.
Closes#17546.
Adds two error codes, one for duplicate associated constants and one for types. I'm not certain these should each have their own code, but E0201 is already solely for duplicate associated functions so at least it kinda matches. This will lead to somewhat redundant error explanations, but that's nothing new!
Fixes#23969.
Expands E0201 to be used for any duplicate associated items, not just duplicate
methods/functions. It also correctly detects when two different kinds of items
(like a constant and a method) have the same name.
Fixes#23969.
This PR modernizes some names in the type checker. The only remaining snake_case name in ty.rs is `ctxt` which should be resolved by @eddyb's pending refactor. We can bike shed over the names, it would just be nice to bring the type checker inline with modern Rust.
r? @eddyb
cc @nikomatsakis
In a followup to PR #26849, improve one more location for I/O where
we can use `Vec::resize` to ensure better performance when zeroing
buffers.
Use the `vec![elt; n]` macro everywhere we can in the tree. It replaces
`repeat(elt).take(n).collect()` which is more verbose, requires type
hints, and right now produces worse code. `vec![]` is preferable for vector
initialization.
The `vec![]` replacement touches upon one I/O path too, Stdin::read
for windows, and that should be a small improvement.
r? @alexcrichton
The common pattern `iter::repeat(elt).take(n).collect::<Vec<_>>()` is
exactly equivalent to `vec![elt; n]`, do this replacement in the whole
tree.
(Actually, vec![] is smart enough to only call clone n - 1 times, while
the former solution would call clone n times, and this fact is
virtually irrelevant in practice.)
`MethodCallee` now has no information about the method, other than its `DefId`.
The previous bits of information can be recovered as follows:
```rust
let method_item = tcx.impl_or_trait_item(callee.def_id);
let container = method_item.container();
```
The method is inherent if `container` is a `ty::ImplContainer`:
* the `impl` the method comes from is `container.id()`
The method is a trait method if `container` is a `ty::TraitContainer:
* the `trait` the method is part of is `container.id()`
* a `ty::TraitRef` can be constructed by putting together:
* `container.id()` as the `trait` ID
* `callee.substs.clone().method_to_trait()` as the `trait` substs (including `Self`)
* the above `trait_ref` is a valid `T: Trait<A, B, C>` predicate
* selecting `trait_ref` could result in one of the following:
* `traits::VtableImpl(data)`: static dispatch to `data.impl_def_id`
* `traits::VtableObject(data)`: dynamic dispatch, with the vtable index:
`traits::get_vtable_index_of_object_method(tcx, data, callee.def_id)`
* other variants of `traits::Vtable`: various other `impl` sources
