Implementation of repr struct alignment RFC 1358.
The main changes around rustc::ty::Layout::struct:
* Added abi_align field which stores abi alignment before repr align is applied
* align field contains transitive repr alignment
* Added padding vec which stores padding required after fields
The main user of this information is rustc_trans::adt::struct_llfields
which determines the LLVM fields to be used by LLVM, including padding
fields.
A possible future optimisation would be to put the padding Vec in an Option, since it will be unused unless you are using repr align.
When a span starts on a line with nothing but whitespace to the left,
and there are no other annotations in that line, simplify the visual
representation of the span.
Go from:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | struct A {
| _^ starting here...
2 | | a: A,
3 | | }
| |_^ ...ending here: recursive type has infinite size
|
```
To:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | / struct A {
2 | | a: A,
3 | | }
| |_^ recursive type has infinite size
```
Remove `starting here...`/`...ending here` labels from all multiline
diagnostics.
The main changes around rustc::ty::Layout::struct and rustc_trans:adt:
* Added primitive_align field which stores alignment before repr align
* Always emit field padding when generating the LLVM struct fields
* Added methods for adjusting field indexes from the layout index to the
LLVM struct field index
The main user of this information is rustc_trans::adt::struct_llfields
which determines the LLVM fields to be used by LLVM, including padding
fields.
Add a way to get shorter spans until `char` for pointing at defs
```rust
error[E0072]: recursive type `X` has infinite size
--> file.rs:10:1
|
10 | struct X {
| ^^^^^^^^ recursive type has infinite size
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `X` representable
```
vs
```rust
error[E0072]: recursive type `X` has infinite size
--> file.rs:10:1
|
10 | struct X {
| _^ starting here...
11 | | x: X,
12 | | }
| |_^ ...ending here: recursive type has infinite size
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `X` representable
```
Re: #35965, #38246. Follow up to #38328.
r? @jonathandturner
Highlight and simplify mismatched types
Shorten mismatched types errors by replacing subtypes that are not
different with `_`, and highlighting only the subtypes that are
different.
Given a file
```rust
struct X<T1, T2> {
x: T1,
y: T2,
}
fn foo() -> X<X<String, String>, String> {
X { x: X {x: "".to_string(), y: 2}, y: "".to_string()}
}
fn bar() -> Option<String> {
"".to_string()
}
```
provide the following output
```rust
error[E0308]: mismatched types
--> file.rs:6:5
|
6 | X { x: X {x: "".to_string(), y: 2}, y: "".to_string()}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `std::string::String`, found {integer}
|
= note: expected type `X<X<_, std::string::String>, _>`
^^^^^^^^^^^^^^^^^^^ // < highlighted
found type `X<X<_, {integer}>, _>`
^^^^^^^^^ // < highlighted
error[E0308]: mismatched types
--> file.rs:6:5
|
10 | "".to_string()
| ^^^^^^^^^^^^^^ expected struct `std::option::Option`, found `std::string::String`
|
= note: expected type `Option<std::string::String>`
^^^^^^^ ^ // < highlighted
found type `std::string::String`
```
Fix#21025. Re: #40186. Follow up to #39906.
I'm looking to change how this output is accomplished so that it doesn't create list of strings to pass around, but rather add an elided `Ty` placeholder, and use the same string formatting for normal types. I'll be doing that soonish.
r? @nikomatsakis
Use proper span for tuple index parsed as float
Fix diagnostic suggestion from:
```rust
help: try parenthesizing the first index
| (1, (2, 3)).((1, (2, 3)).1).1;
```
to the correct:
```rust
help: try parenthesizing the first index
| ((1, (2, 3)).1).1;
```
Fix#41081.
```rust
error[E0072]: recursive type `X` has infinite size
--> file.rs:10:1
|
10 | struct X {
| ^^^^^^^^ recursive type has infinite size
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `X` representable
```
vs
```rust
error[E0072]: recursive type `X` has infinite size
--> file.rs:10:1
|
10 | struct X {
| _^ starting here...
11 | | x: X,
12 | | }
| |_^ ...ending here: recursive type has infinite size
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `X` representable
```
Point at only one char on `Span::next_point`
Avoid pointing at two chars so the diagnostic output doesn't display a
multiline span when starting beyond a line end.
Fix#41155.
Instead of
```rust
error: expected one of `(`, `const`, `default`, `extern`, `fn`, `type`, or `unsafe`, found `}`
--> <anon>:3:1
|
1 | impl S { pub
| _____________- starting here...
2 | |
| | ...ending here: expected one of 7 possible tokens here
3 | }
| ^ unexpected token
```
show
```rust
error: expected one of `(`, `const`, `default`, `extern`, `fn`, `type`, or `unsafe`, found `}`
--> <anon>:13:1
|
12 | pub
| - expected one of 7 possible tokens here
13 | }
| ^ unexpected token
```
Explicit help message for binop type mismatch
When trying to do `1 + Some(2)`, or some other binary operation on two
types different types without an appropriate trait implementation, provide
an explicit help message:
```rust
help: `{integer} + std::option::Option<{integer}>` has no implementation
```
Re: #39579, #38564, #37626, #39942, #34698.
When trying to do a binary operation with missing implementation, for
example `1 + Some(2)`, provide an explicit help message:
```
note: no implementation for `{integer} + std::option::Option<{integer}>`
```
Use `rustc_on_unimplemented` for the suggestions. Move cfail test to ui.
don't try to blame tuple fields for immutability
Tuple fields don't have an `&T` in their declaration that can be changed
to `&mut T` - skip them..
Fixes#41104.
r? @nikomatsakis
Make 'overlapping_inherent_impls' lint a hard error
This is ought to be implemented in PR #40728. Unfortunately, when I rebased the PR to resolve merge conflict, the "hard error" code disappeared. This PR complements the initial PR.
Now the following rust code gives the following error:
```rust
struct Foo;
impl Foo {
fn id() {}
}
impl Foo {
fn id() {}
}
fn main() {}
```
```
error[E0592]: duplicate definitions with name `id`
--> /home/topecongiro/test.rs:4:5
|
4 | fn id() {}
| ^^^^^^^^^^ duplicate definitions for `id`
...
8 | fn id() {}
| ---------- other definition for `id`
error: aborting due to previous error
```
Fix diagnostic suggestion from:
```rust
help: try parenthesizing the first index
| (1, (2, 3)).((1, (2, 3)).1).1;
```
to the correct:
```rust
help: try parenthesizing the first index
| ((1, (2, 3)).1).1;
```
Do not recommend private fields called as method
```rust
error: no method named `dog_age` found for type `animal::Dog` in the current scope
--> $DIR/private-field.rs:26:23
|
26 | let dog_age = dog.dog_age();
| ^^^^^^^ private field, not a method
```
Fix#27654.
