This fixes a bug in which the visibility of a use declaration defining a name in one namespace (e.g. the value namespace) is overridden by a later use declaration defining the same name in the other namespace (e.g. the type namespace). For example,
```rust
fn f() {}
pub mod bar {}
mod foo {
use f; // This import should not be visible outside `foo`,
pub use bar as f; // but it visible outside of `foo` because of this import.
}
fn main() { foo::f(); }
```
As the example demonstrates, this is a [breaking-change], but it looks unlikely to cause breakage in practice, and any breakage can be fixed by correcting visibility modifiers.
This PR makes `Mir` `RustcEncodable` and `RustcDecodable` and stores it in crate metadata for inlinable items.
Some other things in here:
- `mir::visit::Visitor` is extended to also visit `Literals`, `Spans` and `DefIds`.
- It also adds `mir::visit::MutVisitor` which allows to mutate the visited `Mir` structure in place.
- Some numbers on how big MIR is in metadata (total metadata size in bytes):
| | w/ MIR | w/o MIR | Rel. Size |
|----------------|-----------:|------------:|:---------:|
| libcore | 17,695,473 | 14,263,377 | 124% |
| liblibc | 411,440 | 404,382 | 102% |
| libcollections | 4,537,975 | 3,526,933 | 129% |
| libserialize | 2,574,769 | 2,060,798 | 125% |
| libsyntax | 15,262,894 | 12,075,574 | 126% |
| librustc | 16,984,537 | 13,692,168 | 124% |
So, adding MIR to metadata makes it about 25% bigger. It could be worse, considering that it still uses the inefficient RBML encoding. Still, the question is whether we should put MIR emission behind a `-Z` flag.
This changes the error output and behaviour to:
* not emit python backtraces
* run all checks
* include a context line per error
* move the offending line-number to the start of the line
fixes#21455
This is a standard "clean out libstd" commit which removes all 1.5-and-before
deprecated functionality as it's now all been deprecated for at least one entire
cycle.
This is a standard "clean out libstd" commit which removes all 1.5-and-before
deprecated functionality as it's now all been deprecated for at least one entire
cycle.
I meant to double check the work in https://github.com/rust-lang/rust/issues/29429, but due to Mozlando, forgot. Here are two small fixes.
r? @brson I would like to get this backported to beta as well, sorry :( I don't generally want doc backports, but feel this is exceptional and worth it.
With this commit, metadata encoding and decoding can make use of thread-local encoding and decoding contexts. These allow implementers of `serialize::Encodable` and `Decodable` to access information and
datastructures that would otherwise not be available to them. For example, we can automatically translate def-id and span information during decoding because the decoding context knows which crate the data is decoded from. Or it allows to make `ty::Ty` decodable because the context has access to the `ty::ctxt` that is needed for creating `ty::Ty` instances.
Some notes:
- `tls::with_encoding_context()` and `tls::with_decoding_context()` (as opposed to their unsafe versions) try to prevent the TLS data getting out-of-sync by making sure that the encoder/decoder passed in is actually the same as the one stored in the context. This should prevent accidentally reading from the wrong decoder.
- There are no real tests in this PR. I had a unit tests for some of the core aspects of the TLS implementation but it was kind of brittle, a lot of code for mocking `ty::ctxt`, `crate_metadata`, etc and did actually test not so much. The code will soon be tested by the first incremental compilation auto-tests that rely on MIR being properly serialized. However, if people think that some tests should be added before this can land, I'll try to provide some that make sense.
r? @nikomatsakis
With this commit, metadata encoding and decoding can make use of
thread-local encoding and decoding contexts. These allow implementers
of serialize::Encodable and Decodable to access information and
datastructures that would otherwise not be available to them. For
example, we can automatically translate def-id and span information
during decoding because the decoding context knows which crate the
data is decoded from. Or it allows to make ty::Ty decodable because
the context has access to the ty::ctxt that is needed for creating
ty::Ty instances.
The `rsbegin.o` and `rsend.o` build products should not be generated
on non WinGnu platforms.
This is another path to resolving #30063 for non win-gnu targets.
(And it won't require a snapshot, unlike PR #30208.)
r? @alexcrichton
