This PR is a rebase of the original PR by @eddyb https://github.com/rust-lang/rust/pull/21836 with some unrebasable parts manually reapplied, feature gate added + type equality restriction added as described below.
This implementation is partial because the type equality restriction is applied to all type ascription expressions and not only those in lvalue contexts. Thus, all difficulties with detection of these contexts and translation of coercions having effect in runtime are avoided.
So, you can't write things with coercions like `let slice = &[1, 2, 3]: &[u8];`. It obviously makes type ascription less useful than it should be, but it's still much more useful than not having type ascription at all.
In particular, things like `let v = something.iter().collect(): Vec<_>;` and `let u = t.into(): U;` work as expected and I'm pretty happy with these improvements alone.
Part of https://github.com/rust-lang/rust/issues/23416
This PR adds `memchr`and `memrchr` based on @BurntSushi 's rust-memchr crate to libstd (as discussed in #30151).
I've update some places in libstd to use memchr/memrchr, but I am not sure if there are other places where it could be used as well.
ref #30076
Rust already supports Linux's getrandom(2), which is very similar and
was based on getentropy(2). This is a pretty clean, simple addition that
uses the same approach as the iOS randomness API support.
Make RFC 1214 warnings into errors, and rip out the "warn or err"
associated machinery. Future such attempts should go through lints
anyhow.
There is a fair amount of fallout in the compile-fail tests, as WF
checking now occurs earlier in the process.
r? @arielb1
associated machinery. Future such attempts should go through lints
anyhow.
There is a fair amount of fallout in the compile-fail tests, as WF
checking now occurs earlier in the process.
LLVM doesn't really support reusing the same module to emit more than
one file. One bug this causes is that the IR is invalidated by the stack
coloring pass when emitting the first file, and then the IR verifier
complains by the time we try to emit the second file. Also, we get
different binaries with --emit=asm,link than with just --emit=link. In
some cases leading to segfaults.
Unfortunately, it seems that at this point in time, the most sensible
option to circumvent this problem is to just clone the whole llvm module
for the asm output if we need both, asm and obj file output.
Fixes#24876Fixes#26235
previously the error was erased and a `non-const path` error was emitted at the location of the field access instead of at the overflow location (as can be seen in the playground: http://is.gd/EuAF5F )
The previous example had no chance of compiling in either form, due to the restrictive follow set for `ty`. This one has the desired behavior: http://is.gd/kYdw4g (well, I don't exactly desire this behavior at all, but it's true at least :p )
previously the error was erased and a `non-const path` error was emitted at the location of the field access instead of at the overflow location (as can be seen in the playground: http://is.gd/EuAF5F )
LLVM doesn't really support reusing the same module to emit more than
one file. One bug this causes is that the IR is invalidated by the stack
coloring pass when emitting the first file, and then the IR verifier
complains by the time we try to emit the second file. Also, we get
different binaries with --emit=asm,link than with just --emit=link. In
some cases leading to segfaults.
Unfortunately, it seems that at this point in time, the most sensible
option to circumvent this problem is to just clone the whole llvm module
for the asm output if we need both, asm and obj file output.
Fixes#24876Fixes#26235
It looks like #27937 accidentally switched the llvmdeps file from the target to
the host by accident, so be sure to use the right llvmdeps file which is built
for the target when building rustc_llvm
