Fix soundness bug described in #29859
This is an attempt at fixing the problems described in #29859 based on an IRC conversation between @nikomatsakis and I today. I'm waiting on a full build to come back, otherwise both tests trigger the correct error.
resolve: Suggest `use self` when import resolves
Improves errors messages by replacing "Maybe a missing `extern crate`" messages
with "Did you mean `self::...`" when the `self` import would succeed.
Fixes#34191.
Thank you for the help @jseyfried!
Fix "field is never used" warning to take unions into account
When compiling code containing a union with an unused field, rustc says
"struct field is never used".
Rather than saying "struct or union", or adding logic to determine the
type of the item, just change the message to "field is never used",
dropping the "struct".
Update tests accordingly.
Updated E0559 to new format
Refactored a method that printed one suggested field name,
into a method that returns an `Option` of a suggestion
(Updated test cases accordingly)
r? @jonathandturner
Closes#36197
Update Error format for E0516, E0517, E0518
- E0518 Update error format #36111
- E0517 Update error format #36109
- E0516 Update error format #36108
- Part of #35233
r? @jonathandturner
Updated e0493 to new format (+ bonus).
Part of #35233.
Fixes#35999.
r? @jonathandturner
I'm not satisfied with the bonus part, there has to be an easier way to reach into the `Drop`'s span implementation. I'm all ears. :)
Rather than saying "struct or union" or adding logic to determine the
type of the item, just change the message to "field is never used",
dropping the "struct".
Update tests accordingly.
rustc: Implement custom derive (macros 1.1)
This commit is an implementation of [RFC 1681] which adds support to the
compiler for first-class user-define custom `#[derive]` modes with a far more
stable API than plugins have today.
[RFC 1681]: https://github.com/rust-lang/rfcs/blob/master/text/1681-macros-1.1.md
The main features added by this commit are:
* A new `rustc-macro` crate-type. This crate type represents one which will
provide custom `derive` implementations and perhaps eventually flower into the
implementation of macros 2.0 as well.
* A new `rustc_macro` crate in the standard distribution. This crate will
provide the runtime interface between macro crates and the compiler. The API
here is particularly conservative right now but has quite a bit of room to
expand into any manner of APIs required by macro authors.
* The ability to load new derive modes through the `#[macro_use]` annotations on
other crates.
All support added here is gated behind the `rustc_macro` feature gate, both for
the library support (the `rustc_macro` crate) as well as the language features.
There are a few minor differences from the implementation outlined in the RFC,
such as the `rustc_macro` crate being available as a dylib and all symbols are
`dlsym`'d directly instead of having a shim compiled. These should only affect
the implementation, however, not the public interface.
This commit also ended up touching a lot of code related to `#[derive]`, making
a few notable changes:
* Recognized derive attributes are no longer desugared to `derive_Foo`. Wasn't
sure how to keep this behavior and *not* expose it to custom derive.
* Derive attributes no longer have access to unstable features by default, they
have to opt in on a granular level.
* The `derive(Copy,Clone)` optimization is now done through another "obscure
attribute" which is just intended to ferry along in the compiler that such an
optimization is possible. The `derive(PartialEq,Eq)` optimization was also
updated to do something similar.
---
One part of this PR which needs to be improved before stabilizing are the errors
and exact interfaces here. The error messages are relatively poor quality and
there are surprising spects of this such as `#[derive(PartialEq, Eq, MyTrait)]`
not working by default. The custom attributes added by the compiler end up
becoming unstable again when going through a custom impl.
Hopefully though this is enough to start allowing experimentation on crates.io!
Fixed E0529's label and unit test
Fixes#36195 part of #35233.
This is ready for review, but will likely fail Travis due to #36138. I changed the wording of the label, so feedback on that would be appreciated.
r? @jonathandturner
Update lifetime errors to specifically note temporaries
This PR updates the error message we give in the case of a temporary value not living long enough.
Before:
<img width="497" alt="screen shot 2016-08-31 at 10 02 47 am" src="https://cloud.githubusercontent.com/assets/547158/18138551/27a06794-6f62-11e6-9ee2-bdf8bed75ca7.png">
Now:
<img width="488" alt="screen shot 2016-08-31 at 10 03 01 am" src="https://cloud.githubusercontent.com/assets/547158/18138557/2e5cf322-6f62-11e6-9047-4a78abf3d78c.png">
Specifically, it makes the following changes:
* Detects if a temporary is being used. If so, it changes the labels to mention that a temporary value specifically is in question
* Simplifies wording of the existing labels to focus on lifetimes rather than values being valid
* Changes the help to a note, since the help+span wasn't as helpful (and sometimes more confusing) than just a note.
r? @nikomatsakis
This commit is an implementation of [RFC 1681] which adds support to the
compiler for first-class user-define custom `#[derive]` modes with a far more
stable API than plugins have today.
[RFC 1681]: https://github.com/rust-lang/rfcs/blob/master/text/1681-macros-1.1.md
The main features added by this commit are:
* A new `rustc-macro` crate-type. This crate type represents one which will
provide custom `derive` implementations and perhaps eventually flower into the
implementation of macros 2.0 as well.
* A new `rustc_macro` crate in the standard distribution. This crate will
provide the runtime interface between macro crates and the compiler. The API
here is particularly conservative right now but has quite a bit of room to
expand into any manner of APIs required by macro authors.
* The ability to load new derive modes through the `#[macro_use]` annotations on
other crates.
All support added here is gated behind the `rustc_macro` feature gate, both for
the library support (the `rustc_macro` crate) as well as the language features.
There are a few minor differences from the implementation outlined in the RFC,
such as the `rustc_macro` crate being available as a dylib and all symbols are
`dlsym`'d directly instead of having a shim compiled. These should only affect
the implementation, however, not the public interface.
This commit also ended up touching a lot of code related to `#[derive]`, making
a few notable changes:
* Recognized derive attributes are no longer desugared to `derive_Foo`. Wasn't
sure how to keep this behavior and *not* expose it to custom derive.
* Derive attributes no longer have access to unstable features by default, they
have to opt in on a granular level.
* The `derive(Copy,Clone)` optimization is now done through another "obscure
attribute" which is just intended to ferry along in the compiler that such an
optimization is possible. The `derive(PartialEq,Eq)` optimization was also
updated to do something similar.
---
One part of this PR which needs to be improved before stabilizing are the errors
and exact interfaces here. The error messages are relatively poor quality and
there are surprising spects of this such as `#[derive(PartialEq, Eq, MyTrait)]`
not working by default. The custom attributes added by the compiler end up
becoming unstable again when going through a custom impl.
Hopefully though this is enough to start allowing experimentation on crates.io!
syntax-[breaking-change]
