This can break code that looked like:
impl Foo for Box<Any> {
fn f(&self) { ... }
}
let x: Box<Any + Send> = ...;
x.f();
Change such code to:
impl Foo for Box<Any> {
fn f(&self) { ... }
}
let x: Box<Any> = ...;
x.f();
That is, upcast before calling methods.
This is a conservative solution to #5781. A more proper treatment (see
the xfail'd `trait-contravariant-self.rs`) would take variance into
account. This change fixes the soundness hole.
Some library changes had to be made to make this work. In particular,
`Box<Any>` is no longer showable, and only `Box<Any+Send>` is showable.
Eventually, this restriction can be lifted; for now, it does not prove
too onerous, because `Any` is only used for propagating the result of
task failure.
This patch also adds a test for the variance inference work in #12828,
which accidentally landed as part of DST.
Closes#5781.
[breaking-change]
Since procs do not have lifetime bounds, we must do this to maintain
safety.
This can break code that incorrectly captured references in procedure
types. Change such code to not do this, perhaps with a trait object
instead.
A better solution would be to add higher-rank lifetime support to procs.
However, this would be a lot of work for a feature we want to remove in
favor of unboxed closures. The corresponding "real fix" is #15067.
Closes#14036.
[breaking-change]
It turns out that bindings introduced by 'for' loops were not treated hygienically. The fix for this is to make the 'for' expansion more like a macro; rather than expanding sub-pieces and then assembling them, we need to rewrite the for and then call expand again on the whole thing.
This PR includes a test and the fix.
It also contains a number of other things:
- unit tests for other forms of hygiene (currently ignored)
- a fix for the isaac.rs macro that (it turned out) was relying on capturing
- other miscellaneous cleanup and comments
This will break code like:
fn f(x: &mut int) {}
let mut a = box 1i;
f(a);
Change it to:
fn f(x: &mut int) {}
let mut a = box 1i;
f(&mut *a);
RFC 33; issue #10504.
[breaking-change]
r? @brson
vector-reference-to-unsafe-pointer-to-element cast if the type to be
casted to is not fully specified.
This is a conservative change to fix the user-visible symptoms of the
issue. A more flexible treatment would delay cast checks to after
function typechecking.
This can break code that did:
let x: *u8 = &([0, 0]) as *_;
Change this code to:
let x: *u8 = &([0, 0]) as *u8;
Closes#14893.
[breaking-change]
This will break code like:
fn f(x: &mut int) {}
let mut a = box 1i;
f(a);
Change it to:
fn f(x: &mut int) {}
let mut a = box 1i;
f(&mut *a);
RFC 33; issue #10504.
[breaking-change]
Closes#14482 (std: Bring back half of Add on String)
Closes#15026 (librustc: Remove the fallback to `int` from typechecking.)
Closes#15119 (Add more description to c_str::unwrap().)
Closes#15120 (Add tests for #12470 and #14285)
Closes#15122 (Remove the cheat sheet.)
Closes#15126 (rustc: Always include the morestack library)
Closes#15127 (Improve ambiguous pronoun.)
Closes#15130 (Fix#15129)
Closes#15131 (Add the Guide, add warning to tutorial.)
Closes#15134 (Xfailed tests for hygiene, etc.)
Closes#15135 (core: Add stability attributes to Clone)
Closes#15136 (Some minor improvements to core::bool)
Closes#15137 (std: Add stability attributes to primitive numeric modules)
Closes#15141 (Fix grammar in tutorial)
Closes#15143 (Remove few FIXMEs)
Closes#15145 (Avoid unnecessary temporary on assignments)
Closes#15147 (Small improvements for metaprogramming)
Closes#15153 (librustc: Check function argument patterns for legality of by-move)
Closes#15154 (test: Add a test for regions, traits, and variance.)
Closes#15159 (rustc: Don't register syntax crates twice)
Closes#13816 (Stabilize version output for rustc and rustdoc)
bindings.
This will break code that incorrectly did things like:
fn f(a @ box b: Box<String>) {}
Fix such code to not rely on undefined behavior.
Closes#12534.
[breaking-change]
The #14869 removed `TraitStore` from `ty_trait` and represented trait
reference as regular `ty_rptr`. An old bug of the missing constraint
upon lifetime parameter of trait reference then is fixed as a side
effect. Adds tests for affected bugs and closes them.
Closes#12470.
Closes#14285.
This breaks a fair amount of code. The typical patterns are:
* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;
* `println!("{}", 3)`: change to `println!("{}", 3i)`;
* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.
RFC #30. Closes#6023.
[breaking-change]
If you define lang items in your crate, add `#[feature(lang_items)]`.
If you define intrinsics (`extern "rust-intrinsic"`), add
`#[feature(intrinsics)]`.
Closes#12858.
[breaking-change]
Unit-like structs are written as `struct Foo;`, but we erroneously
accepted `struct Foo();` and took it to mean the same thing. Now we
don't, so use the `struct Foo;` form!
[breaking-change]
This commit makes several changes to the stability index infrastructure:
* Stability levels are now inherited lexically, i.e., each item's
stability level becomes the default for any nested items.
* The computed stability level for an item is stored as part of the
metadata. When using an item from an external crate, this data is
looked up and cached.
* The stability lint works from the computed stability level, rather
than manual stability attribute annotations. However, the lint still
checks only a limited set of item uses (e.g., it does not check every
component of a path on import). This will be addressed in a later PR,
as part of issue #8962.
* The stability lint only applies to items originating from external
crates, since the stability index is intended as a promise to
downstream crates.
* The "experimental" lint is now _allow_ by default. This is because
almost all existing crates have been marked "experimental", pending
library stabilization. With inheritance in place, this would generate
a massive explosion of warnings for every Rust program.
The lint should be changed back to deny-by-default after library
stabilization is complete.
* The "deprecated" lint still warns by default.
The net result: we can begin tracking stability index for the standard
libraries as we stabilize, without impacting most clients.
Closes#13540.
This PR is changing the error messages for non-exhaustive pattern matching to include a more accurate witness, i.e. a pattern that is not covered by any of the ones provided by the user. Example:
```rust
fn main() {
match (true, (Some("foo"), [true, true]), Some(42u)) {
(false, _, _) => (),
(true, (None, [true, _]), None) => (),
(true, (None, [false, _]), Some(1u)) => ()
}
}
```
```sh
/tmp/witness.rs:2:2: 6:3 error: non-exhaustive patterns: (true, (core::option::Some(_), _), _) not covered
/tmp/witness.rs:2 match (true, (Some("foo"), [true, true]), Some(42u)) {
/tmp/witness.rs:3 (false, _, _) => (),
/tmp/witness.rs:4 (true, (None, [true, _]), None) => (),
/tmp/witness.rs:5 (true, (None, [false, _]), Some(1u)) => ()
/tmp/witness.rs:6 }
```
As part of that, I refactored some of the relevant code and carried over the changes to fixed vectors from the previous PR.
I'm putting it out there for now but the tests will be red.
Closes#8142.
This is not the semantics we want long-term. You can continue to use
`#[unsafe_destructor]`, but you'll need to add
`#![feature(unsafe_destructor)]` to the crate attributes.
[breaking-change]
This commit makes several changes to the stability index infrastructure:
* Stability levels are now inherited lexically, i.e., each item's
stability level becomes the default for any nested items.
* The computed stability level for an item is stored as part of the
metadata. When using an item from an external crate, this data is
looked up and cached.
* The stability lint works from the computed stability level, rather
than manual stability attribute annotations. However, the lint still
checks only a limited set of item uses (e.g., it does not check every
component of a path on import). This will be addressed in a later PR,
as part of issue #8962.
* The stability lint only applies to items originating from external
crates, since the stability index is intended as a promise to
downstream crates.
* The "experimental" lint is now _allow_ by default. This is because
almost all existing crates have been marked "experimental", pending
library stabilization. With inheritance in place, this would generate
a massive explosion of warnings for every Rust program.
The lint should be changed back to deny-by-default after library
stabilization is complete.
* The "deprecated" lint still warns by default.
The net result: we can begin tracking stability index for the standard
libraries as we stabilize, without impacting most clients.
Closes#13540.
The lexer already ignores CRLF in between tokens, but it doesn't
properly handle carriage returns inside strings and doc comments. Teach
it to treat CRLF as LF inside these tokens, and to disallow carriage
returns that are not followed by linefeeds. This includes handling an
escaped CRLF inside a regular string token the same way it handles an
escaped LF.
This is technically a breaking change, as bare carriage returns are no
longer allowed, and CRLF sequences are now treated as LF inside strings
and doc comments, but it's very unlikely to actually affect any
real-world code.
This change is necessary to have Rust code compile on Windows the same
way it does on Unix. The mozilla/rust repository explicitly sets eol=lf
for Rust source files, but other Rust repositories don't. Notably,
rust-http cannot be compiled on Windows without converting the CRLF line
endings back to LF.
[breaking-change]
The lexer already ignores CRLF in between tokens, but it doesn't
properly handle carriage returns inside strings and doc comments. Teach
it to treat CRLF as LF inside these tokens, and to disallow carriage
returns that are not followed by linefeeds. This includes handling an
escaped CRLF inside a regular string token the same way it handles an
escaped LF.
This is technically a breaking change, as bare carriage returns are no
longer allowed, and CRLF sequences are now treated as LF inside strings
and doc comments, but it's very unlikely to actually affect any
real-world code.
This change is necessary to have Rust code compile on Windows the same
way it does on Unix. The mozilla/rust repository explicitly sets eol=lf
for Rust source files, but other Rust repositories don't. Notably,
rust-http cannot be compiled on Windows without converting the CRLF line
endings back to LF.
[breaking-change]
Replace its usage with byte string literals, except in `bytes!()` tests.
Also add a new snapshot, to be able to use the new b"foo" syntax.
The src/etc/2014-06-rewrite-bytes-macros.py script automatically
rewrites `bytes!()` invocations into byte string literals.
Pass it filenames as arguments to generate a diff that you can inspect,
or `--apply` followed by filenames to apply the changes in place.
Diffs can be piped into `tip` or `pygmentize -l diff` for coloring.
thereof.)
PR 14739 injected the new message that this removes from one test
case: borrowck-vec-pattern-loan-from-mut.rs
When reviewing the test case, I was not able to convince myself that
the error message was a legitimate thing to start emitting. Niko did
not see an obvious reason for it either, so I am going to remove it
and wait for someone (maybe Cameron Zwarich) to explain to me why we
should be emitting it.
