By RFC1214:
> Before calling a fn, we check that its argument and return types are WF.
The previous code only checked the trait-ref, which was not enough
in several cases.
As this is a soundness fix, it is a [breaking-change]. Some new annotations are needed, which I think are because of #18653 and the imperfection of `projection_must_outlive` (that can probably be worked around by moving the wf obligation later).
Fixes#28609
r? @nikomatsakis
By RFC1214:
Before calling a fn, we check that its argument and return types are WF. This check takes place after all higher-ranked lifetimes have been instantiated. Checking the argument types ensures that the implied bounds due to argument types are correct. Checking the return type ensures that the resulting type of the call is WF.
The previous code only checked the trait-ref, which was not enough
in several cases.
As this is a soundness fix, it is a [breaking-change].
Fixes#28609
This PR closes out #28716 and #28735 by making two changes to the compiler:
1. The `--emit` flag to the compiler now supports the ability to specify the output file name of a partuclar emit type. For example `--emit dep-info=bar.d,asm=foo.s,link` is now accepted.
2. The dep-info emission now emits a dummy target for all input file names to protect against deleted files.
The behavior here isn't really ideal, but we can't really do much better
given the current state of constant evaluation.
The changes to ExprUseVisitor are to avoid a compile error; apparently
that bit of code is extremely sensitive to changes in other areas of the
compiler.
Fixes#28670, and probably a bunch of duplicates.
This commit swaps the order of linking local native libraries and upstream
native libraries on the linker command line. Detail of bugs this can cause can
be found in #28595, and this change also invalidates the test case that was
added for #12446 which is now considered a bug because the downstream dependency
would need to declare that it depends on the native library somehow.
Closes#28595
The behavior here isn't really ideal, but we can't really do much better
given the current state of constant evaluation.
Fixes#28670, and probably a bunch of duplicates.
Currently the compiler supports the ability to emit multiple output types as
part of one compilation (e.g. asm, LLVM IR, bytecode, link, dep-info, etc). It
does not, however, support the ability to customize the output filename for each
of these output types. The `-o` flag is ignored if multiple emit types are
specified (and the compiler emits a warning about this).
Normally this doesn't matter too much, but in the case of `dep-info` it can lead
to a number of problems (e.g. see #28716). By allowing customization of the
output filename for each emit type we're able to solve the problems in that
issue.
This commit adds support for the `--emit` option to the compiler to look like:
rustc foo.rs --emit dep-info=.deps/foo.d,link
This indicates that the `dep-info` output type will be placed at `.deps/foo.d`
and the `link` output type will otherwise be determined via the `--out-dir` and
`-o` flags.
Closes#28716
Travis CI has new infrastructure using the Google Compute Engine which has both
faster CPUs and more memory, and we've been encouraged to switch as it should
help our build times! The only downside currently, however, is that IPv6 is
disabled, causing a number of standard library tests to fail.
Consequently this commit tweaks our travis config in a few ways:
* ccache is disabled as it's not working on GCE just yet
* Docker is used to run tests inside which reportedly will get IPv6 working
* A system LLVM installation is used instead of building LLVM itself. This is
primarily done to reduce build times, but we want automation for this sort of
behavior anyway and we can extend this in the future with building from source
as well if needed.
* gcc-specific logic is removed as the docker image for Ubuntu gives us a
recent-enough gcc by default.
I just removed the num_cpus dependency (because we don't want that in there), using 4 threads instead.
I should add that Veedrac asked me to submit this here in his name.
By putting an "unreachable" instruction into the default arm of a switch
instruction we can let LLVM know that the match is exhaustive, allowing
for better optimizations.
For example, this match:
```rust
pub enum Enum {
One,
Two,
Three,
}
impl Enum {
pub fn get_disc(self) -> u8 {
match self {
Enum::One => 0,
Enum::Two => 1,
Enum::Three => 2,
}
}
}
```
Currently compiles to this on x86_64:
```asm
.cfi_startproc
movzbl %dil, %ecx
cmpl $1, %ecx
setne %al
testb %cl, %cl
je .LBB0_2
incb %al
movb %al, %dil
.LBB0_2:
movb %dil, %al
retq
.Lfunc_end0:
```
But with this change we get:
```asm
.cfi_startproc
movb %dil, %al
retq
.Lfunc_end0:
```
As discussed in the referenced issues, this PR makes rustc emit `__imp_<symbol>` stubs for all public static data to ensure smooth linking in on `-windows-msvc` targets.
Resolves#26591, cc #27438
This commit updates the `MatchIndices` and `RMatchIndices` iterators to follow
the same pattern as the `chars` and `char_indices` iterators. The `matches`
iterator currently yield `&str` elements, so the `MatchIndices` iterator now
yields the index of the match as well as the `&str` that matched (instead of
start/end indexes).
cc #27743
Because of type inference, duplicate obligations exist and cause duplicate
errors. To avoid this, only display the first error for each (predicate,span).
The inclusion of the span is somewhat bikesheddy, but *is* the more
conservative option (it does not remove some instability, as duplicate
obligations are ignored by `duplicate_set` under some inference conditions).
Fixes#28098
cc #21528 (is it a dupe?)
This PR removes random remaining `Ident`s outside of libsyntax and performs general cleanup
In particular, interfaces of `Name` and `Ident` are tidied up, `Name`s and `Ident`s being small `Copy` aggregates are always passed to functions by value, and `Ident`s are never used as keys in maps, because `Ident` comparisons are tricky.
Although this PR closes https://github.com/rust-lang/rust/issues/6993 there's still work related to it:
- `Name` can be made `NonZero` to compress numerous `Option<Name>`s and `Option<Ident>`s but it requires const unsafe functions.
- Implementation of `PartialEq` on `Ident` should be eliminated and replaced with explicit hygienic, non-hygienic or member-wise comparisons.
- Finally, large parts of AST can potentially be converted to `Name`s in the same way as HIR to clearly separate identifiers used in hygienic and non-hygienic contexts.
r? @nrc
