Avoid ICE in borrowck
Provide a fallback in `best_blame_constraint` when `find_constraint_paths_between_regions` doesn't have a result. This code is due a rework to avoid the letf-over `unwrap()`, but avoids the ICE caused by the repro.
Fix#133252.
Unify fs::copy and io::copy on Linux
Currently, `fs::copy` first tries a regular file copy (via copy_file_range) and then falls back to userspace read/write copying. We should use `io::copy` instead as it tries copy_file_range, sendfile, and splice before falling back to userspace copying. This was discovered here: https://github.com/SUPERCILEX/fuc/issues/40
Perf impact: `fs::copy` will now have two additional statx calls to decide which syscall to use. I wonder if we should get rid of the statx calls and only continue down the next fallback when the relevant syscalls say the FD isn't supported.
fix default-backtrace-ice test
when running `tests/ui/panics/default-backtrace-ice.rs locally it gave this error:
```
failures:
---- [ui] tests/ui/panics/default-backtrace-ice.rs stdout ----
Saved the actual stderr to "/home/jyn/src/rust3/build/x86_64-unknown-linux-gnu/test/ui/panics/default-backtrace-ice/default-backtrace-ice.stderr"
diff of stderr:
7
8 aborting due to `-Z treat-err-as-bug=1`
9 stack backtrace:
- (end_short_backtrace)
- (begin_short_backtrace)
- (end_short_backtrace)
- (begin_short_backtrace)
+ [... omitted 22 frames ...]
+
```
(note that you must *not* use --bless; we previously did not have an error annotation to verify it was a full backtrace instead of a short backtrace.)
this is a regression from setting RUST_BACKTRACE=1 by default in https://github.com/rust-lang/rust/pull/134743. we need to turn off the new behavior when running UI tests so that they reflect our dist compiler. normally that's done by checking `sess.unstable_opts.ui_testing`, but this happens extremely early in the compiler before we've expanded arg files. do an extremely simple hack that doesn't work in all cases - we don't need it to work in all cases, only when running UI tests.
cc https://github.com/rust-lang/rust/pull/129658#issuecomment-2561988081
r? `@jieyouxu`
I'm fairly sure this is more correct, and saves space(~90mb to 82mb
for Zed's index). I'm checking in about this with SCIP folks in
https://github.com/sourcegraph/scip/pull/299.
Before this change `SymbolInformation` provided by a document was the
info for all encountered symbols that have not yet been emitted. So,
the symbol information on a `Document` was a mishmash of symbols
defined in the documents, symbols from other documents, and external
symbols.
After this change, the `SymbolInformation` on documents is just the
locals and defined symbols from the document. All symbols referenced
and not from emitted documents are included in `external_symbols`.
In particular, the symbol generation before this change creates a lot
of symbols with the same name for different definitions. This change
makes progress on symbol uniqueness, but does not fix a couple cases
where it was unclear to me how to fix (see TODOs in `scip.rs`)
Behavior changes:
* `scip` command now reports symbol information omitted due to symbol
collisions. Iterating with this on a large codebase (Zed!) resulted in
the other improvements in this change.
* Generally fixes providing the path to nested definitions in
symbols. Instead of having special cases for a couple limited cases of
nesting, implements `Definition::enclosing_definition` and uses this
to walk definitions.
* Parameter variables are now treated like locals.
- This fixes a bug where closure captures also received symbols
scoped to the containing function. To bring back parameter
symbols I would want a way to filter these out, since they can
cause symbol collisions.
- Having symbols for them seems to be intentional in
27e2eea54f, but no particular use is
specified there. For the typical indexing purposes of SCIP I don't see
why parameter symbols are useful or sensible, as function parameters
are not referencable by anything but position. I can imagine they
might be useful in representing diagnostics or something.
* Inherent impls are now represented as `impl#[SelfType]` - a type
named `impl` which takes a single type parameter.
* Trait impls are now represented as `impl#[SelfType][TraitType]` - a
type named `impl` which takes two type parameters.
* Associated types in traits and impls are now treated like types
instead of type parameters, and so are now suffixed with `#` instead
of wrapped with `[]`. Treating them as type parameters seems to have
been intentional in 73d9c77f2a but it
doesn't make sense to me, so changing it.
* Static variables are now treated as terms instead of `Meta`, and so
receive `.` suffix instead of `:`.
* Attributes are now treated as `Meta` instead of `Macro`, and so
receive `:` suffix instead of `!`.
* `enclosing_symbol` is now provided for labels and generic params,
which are local symbols.
* Fixes a bug where presence of `'` causes a descriptor name to get
double wrapped in backticks, since both `fn new_descriptor` and
`scip::symbol::format_symbol` have logic for wrapping in
backticks. Solution is to simply delete the redundant logic.
* Deletes a couple tests in moniker.rs because the cases are
adequeately covered in scip.rs and the format for identifiers used in
moniker.rs is clunky with the new representation for trait impls
