This PR changes the `emit_opaque` and `read_opaque` methods in the RBML library to use a space-efficient binary encoder that does not emit any tags and uses the LEB128 variable-length integer format for all numbers it emits.
The space savings are nice, albeit a bit underwhelming, especially for dynamic libraries where metadata is already compressed.
| RLIBs | NEW | OLD |
|--------------|--------|-----------|
|libstd | 8.8 MB | 10.5 MB |
|libcore |15.6 MB | 19.7 MB |
|libcollections| 3.7 MB | 4.8 MB |
|librustc |34.0 MB | 37.8 MB |
|libsyntax |28.3 MB | 32.1 MB |
| SOs | NEW | OLD |
|---------------|-----------|--------|
| libstd | 4.8 MB | 5.1 MB |
| librustc | 8.6 MB | 9.2 MB |
| libsyntax | 7.8 MB | 8.4 MB |
At least this should make up for the size increase caused recently by also storing MIR in crate metadata.
Can this be a breaking change for anyone?
cc @rust-lang/compiler
Currently a compiler can be built with the `--disable-elf-tls` option for compatibility with OSX 10.6 which doesn't have ELF TLS. This is unfortunate, however, as a whole new compiler must be generated which can take some time. These commits add a new (feature gated) `cfg(target_thread_local)` annotation set by the compiler which indicates whether `#[thread_local]` is available for use. The compiler now interprets `MACOSX_DEPLOYMENT_TARGET` (a standard environment variable) to set this flag on OSX. With this we may want to start compiling our OSX nightlies with `MACOSX_DEPLOYMENT_TARGET` set to 10.6 which would allow the compiler out-of-the-box to generate 10.6-compatible binaries.
For now the compiler still by default targets OSX 10.7 by allowing ELF TLS by default (e.g. if `MACOSX_DEPLOYMENT_TARGET` isn't set).
Currently the standard library has some pretty complicated logic to detect
whether #[thread_local] should be used or whether it's supported. This is also
unfortunately not quite true for OSX where not all versions support
the #[thread_local] attribute (only 10.7+ does). Compiling code for OSX 10.6 is
typically requested via the MACOSX_DEPLOYMENT_TARGET environment variable (e.g.
the linker recognizes this), but the standard library unfortunately does not
respect this.
This commit updates the compiler to add a `target_thread_local` cfg annotation
if the platform being targeted supports the `#[thread_local]` attribute. This is
feature gated for now, and it is only true on non-aarch64 Linux and 10.7+ OSX
(e.g. what the module already does today). Logic has also been added to parse
the deployment target environment variable.
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
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.
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 )
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 )
Still will not translate references to items like `X` or `Y::V` where
```
struct X;
enum Y { V }
```
but I must go work on university things so I’m PRing what I have.
r? @nikomatsakis
This fixes a bug in which unused imports can get wrongly marked as used when checking for unused qualifications in `resolve_path` (issue #30078), and it removes unused imports that were previously undetected because of the bug.
