This commit changes `ExtCtx::cfg()` so it returns a `CrateConfig`
reference instead of a clone. As a result, it also changes all of the
`cfg()` callsites to explicitly clone... except one, because the commit
also changes `macro_parser::parse()` to take `&CrateConfig`. This is
good, because that function can be hot, and `CrateConfig` is expensive
to clone.
This change almost halves the number of heap allocations done by rustc
for `html5ever` in rustc-benchmarks suite, which makes compilation 1.20x
faster.
There used to be only a global cache, which led to uncached calls to
trait selection when there were type parameters.
I'm running a check that there are no adverse performance effects.
Fixes#37106 (drop elaboration times are now ~half of borrow checking,
so might still be worthy of optimization, but not critical).
Associated type normalization is inhibited by higher-ranked regions.
Therefore, every time we erase them, we must re-normalize.
I was meaning to introduce this change some time ago, but we used
to erase regions in generic context, which broke this terribly (because
you can't always normalize in a generic context). That seems to be gone
now.
Ensure this by having a `erase_late_bound_regions_and_normalize`
function.
Fixes#37109 (the missing call was in mir::block).
macros: clean up scopes of expanded `#[macro_use]` imports
This PR changes the scope of macro-expanded `#[macro_use]` imports to match that of unexpanded `#[macro_use]` imports. For example, this would be allowed:
```rust
example!();
macro_rules! m { () => { #[macro_use(example)] extern crate example_crate; } }
m!();
```
This PR also enforces the full shadowing restrictions from RFC 1560 on `#[macro_use]` imports (currently, we only enforce the weakened restrictions from #36767).
This is a [breaking-change], but I believe it is highly unlikely to cause breakage in practice.
r? @nrc
Error monitor should emit error to stderr instead of stdout
We are pretty consistent about emitting to stderr, except for when there is actually an error, in which case we emit to stdout. This seems a bit backwards. This PR just changes that exception to emit to stderr. This is useful for the RLS since the LS protocol uses stdout (grrr).
r? @alexcrichton
Avoid allocations in `Decoder::read_str`.
`opaque::Decoder::read_str` is very hot within `rustc` due to its use in
the reading of crate metadata, and it currently returns a `String`. This
commit changes it to instead return a `Cow<str>`, which avoids a heap
allocation.
This change reduces the number of calls to `malloc` by almost 10% in
some benchmarks.
This is a [breaking-change] to libserialize.
Add comparison operators to boolean const eval.
I think it might be worth adding tests here, but since I don't know how or where to do that, I have not done so yet. Willing to do so if asked and given an explanation as to how.
Fixes#37047.
In particular, as far as I can tell from the error diagnostics, the
former test for E0199 was actually a test for E0198, and there was no
test for E0198.
(I am assuming that one of my previous changes to the `unsafe impl`
checking fixed a latent bug in how these two cases were
differentiated.)
