debuginfo: Emit ZST struct debuginfo for unit type when CPP-like debuginfo is enabled
As already discovered in 24a728a8eb, PDB does not play well with custom basic types. This PR extends to the fix to `()`: Instead of a custom basic type, we treat it like an empty tuple (i.e. it is described as a struct which happens to have no fields).
Before this change anything with a `()` in it would cause trouble, which is especially bad for `*const ()` and `*mut ()` which are often used for opaque pointers. E.g. the test case added in this PR would look like:
```
0:000> dx _ref
Error: Unable to bind name '_ref'
0:000> dx _ptr
Error: Unable to bind name '_ptr'
0:000> dx _local
Error: Unable to bind name '_local'
0:000> dx _field,d
_field,d [Type: unit_type::_TypeContainingUnitField]
[+0x008] _a : 123 [Type: unsigned int]
[+0x000] _unit : Unexpected failure to dereference object
[+0x000] _b : 456 [Type: unsigned __int64]
0:000> dx ((__int64 *)_ptr),x
Error: Unable to bind name '_ptr'
```
With the PR it produces the expected output:
```
0:000> dx _ref
_ref : 0x7ff6f2012230 : () [Type: tuple$<> *]
0:000> dx _ptr
_ptr : 0x7e8ddffc20 : () [Type: tuple$<> *]
0:000> dx _local
_local : () [Type: tuple$<>]
0:000> dx _field,d
_field,d [Type: unit_type::_TypeContainingUnitField]
[+0x008] _a : 123 [Type: unsigned int]
[+0x000] _unit : () [Type: tuple$<>]
[+0x000] _b : 456 [Type: unsigned __int64]
0:000> dx ((__int64 *)_ptr),x
((__int64 *)_ptr),x : 0x7e8ddffc20 : 0x1122334455667788 [Type: __int64 *]
```
r? `@wesleywiser`
Reduce allocations for path conversions on Windows
Previously, UTF-8 to UTF-16 Path conversions on Windows unnecessarily allocate twice, as described in #96297. This commit fixes that issue.
Improve Windows path prefix parsing
This PR fixes improves parsing of Windows path prefixes. `parse_prefix` now supports both types of separators on Windows (`/` and `\`).
self-profiler: record spans for proc-macro expansions
This PR is a follow-up to #95473, using the arg recorder feature from #95689:
- it adds support code to easily record spans in the event's arguments, when using `generic_activity_with_arg_recorder`.
- uses that to record the spans where proc-macro expansions happen in addition to their name.
As for the other 2 PRs, the goal here is to provide visibility into proc-macro expansion performance, so that users can diagnose which uses of proc-macros in their code could be causing compile time issues.
Some areas where I'd love feedback:
- [x] the API and names: the `SpannedEventArgRecorder` trait and its method, much like #95689 had the same question about the `EventArgRecorder` naming
- [x] we don't currently have a way to record the names of the event arguments, so should `record_arg_spanned` record the span as "location: {}" or similar ?
Rollup of 3 pull requests
Successful merges:
- #96272 (Update `validate_uninhabited_zsts.rs` test after MIR building changes)
- #96273 (Make `E0117` error clear)
- #96315 (Make the lifetime accurate which is used in the region constraints part)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Make the lifetime accurate which is used in the region constraints part
This PR fixes the FIXME about lifetime using in the region constraints part.
We cannot write `<'graph, 'tcx, D>` because the definition of `Successors<'0, '1, D>` requires `'1 : '0`.
We cannot add bound to `'graph` either because `'graph` is required to be an arbitrary value in the definition of `WithSuccessors`
So the most accurate way is to use `<'s, 'tcx, D>`.
cc `@Aaron1011` who added this FIXME in #85343
Update `validate_uninhabited_zsts.rs` test after MIR building changes
to ensure that it still tests validation, instead of failing earlier on
during evaluation.
r? `@RalfJung`
The self-profiler's `EventArgRecorder` is general-purpose in its ability to record Strings (and `rustc_span` depends on the crate its defined in, `rustc_data_structure`).
Some generic activities could use recording locations where they happen in the user's code: to allow e.g. to track macro expansions and diagnose performance issues there.
This adds a `SpannedEventArgRecorder` that can record an argument given as a span, rather than a String, since turning spans into Strings can be tricky if you're not happy with its default Debug output. This way the recorder can have a `record_arg_spanned` method which will do that.
Make all thir types implement clone
This PR adds `Clone` impl to all of the `Thir<'tcx>` types.
I would like to be able to clone a `Thir` body so that I can make a copy in my rustc driver without breaking further compilation. Without this my driver is forced to run in the `after_expansion` callback and thus doesn't benefit from running all the safety checks that `rustc` usually does, instead i need to do them all myself.
`manual_split_once`: lint manual iteration of `SplitN`
changelog: `manual_split_once`: lint manual iteration of `SplitN`
Now lints:
```rust
let mut iter = "a.b.c".splitn(2, '.');
let first = iter.next().unwrap();
let second = iter.next().unwrap();
let mut iter = "a.b.c".splitn(2, '.');
let first = iter.next()?;
let second = iter.next()?;
let mut iter = "a.b.c".rsplitn(2, '.');
let first = iter.next().unwrap();
let second = iter.next().unwrap();
let mut iter = "a.b.c".rsplitn(2, '.');
let first = iter.next()?;
let second = iter.next()?;
```
It suggests (minus leftover whitespace):
```rust
let (first, second) = "a.b.c".split_once('.').unwrap();
let (first, second) = "a.b.c".split_once('.')?;
let (second, first) = "a.b.c".rsplit_once('.').unwrap();
let (second, first) = "a.b.c".rsplit_once('.')?;
```
Currently only lints if the statements are next to each other, as detecting the various kinds of shadowing was tricky, so the following won't lint
```rust
let mut iter = "a.b.c".splitn(2, '.');
let something_else = 1;
let first = iter.next()?;
let second = iter.next()?;
```
Ensure existance of dist directory when creating tarball
I'm not sure why this works in CI, but this is necessary to make distcheck (including the `x86_64-linux-distcheck` image) run on Fedora 35.
This is not super important to do, but the consistency is nice.
I didn't change any tests that call `configure("dist")` and then override the subcommand - doing
that at all is pretty sketchy, but I don't want to mess with it while already doing a refactor.
I didn't know that the `test::` syntax was valid before, and it doesn't
seem to be documented anywhere. Add a test so it doesn't regress accidentally,
and as executable documentation.
rustdoc: Unindent doc fragments on `Attributes` construction
`Attributes` can be constructed at arbitrary points, even after the `unindent_comments` pass.
`Attributes` that are constructed too late end up unindented.
All doc fragments need to be eventually indented before use, so there are no reasons to not do this immediately during their construction.
Fixes https://rust-lang.zulipchat.com/#narrow/stream/266220-rustdoc/topic/.60unindent_comments.60.20cannot.20work.20as.20a.20separate.20pass.
I'm not sure how to make a minimized reproduction, but unindenting the fragments during their construction should fix the issue.. by construction, and I also verified that all doc strings now hit the `resolver_caches.markdown_links` cache in https://github.com/rust-lang/rust/pull/94857.
