NLL: Add union justifications to conflicting borrows.
Fixes#57100.
This PR adds justifications to error messages for conflicting borrows of union fields.
Where previously an error message would say ``cannot borrow `u.b` as mutable..``, it now says ``cannot borrow `u` (via `u.b`) as mutable..``.
r? @pnkfelix
Make `TokenStream` less recursive.
`TokenStream` is currently recursive in *two* ways:
- the `TokenTree` variant contains a `ThinTokenStream`, which can
contain a `TokenStream`;
- the `TokenStream` variant contains a `Vec<TokenStream>`.
The latter is not necessary and causes significant complexity. This
commit replaces it with the simpler `Vec<(TokenTree, IsJoint)>`.
This reduces complexity significantly. In particular, `StreamCursor` is
eliminated, and `Cursor` becomes much simpler, consisting now of just a
`TokenStream` and an index.
The commit also removes the `Extend` impl for `TokenStream`, because it
is only used in tests. (The commit also removes those tests.)
Overall, the commit reduces the number of lines of code by almost 200.
If a match arm does not include all fields in a structure and a later
pattern includes a field that is an array, we will attempt to use the
array type from the prior arm. When calculating the field type, treat
a array of an unknown size as a TyErr.
Rollup of 16 pull requests
Successful merges:
- #57351 (Don't actually create a full MIR stack frame when not needed)
- #57353 (Optimise floating point `is_finite` (2x) and `is_infinite` (1.6x).)
- #57412 (Improve the wording)
- #57436 (save-analysis: use a fallback when access levels couldn't be computed)
- #57453 (lldb_batchmode.py: try `import _thread` for Python 3)
- #57454 (Some cleanups for core::fmt)
- #57461 (Change `String` to `&'static str` in `ParseResult::Failure`.)
- #57473 (std: Render large exit codes as hex on Windows)
- #57474 (save-analysis: Get path def from parent in case there's no def for the path itself.)
- #57494 (Speed up item_bodies for large match statements involving regions)
- #57496 (re-do docs for core::cmp)
- #57508 (rustdoc: Allow inlining of reexported crates and crate items)
- #57547 (Use `ptr::eq` where applicable)
- #57557 (resolve: Mark extern crate items as used in more cases)
- #57560 (hygiene: Do not treat `Self` ctor as a local variable)
- #57564 (Update the const fn tracking issue to the new metabug)
Failed merges:
r? @ghost
Previously calculating glob map was *opt-in*, however it did record
node id -> ident use for every use directive. This aims to see if we
can unconditionally calculate the glob map and not regress performance.
Update the const fn tracking issue to the new metabug
The new `const fn` tracking issue is #57563. We don't want to point to a closed issue in the diagnostics (or FIXMEs), so these have been updated (from the old issue, #24111).
r? @Centril
Use `ptr::eq` where applicable
Stumbled upon a few of `A as *const _ as usize == B as *const as usize`, so I decided to follow the programming boy scout rule (😄) and replaced the pattern with more widely used `ptr::eq`.
rustdoc: Allow inlining of reexported crates and crate items
Fixes#46296
This PR checks for when a `pub extern crate` statement has a `#[doc(inline)]` attribute & inlines its contents. Code is based off of the inlining statements for `pub use` statements.
Speed up item_bodies for large match statements involving regions
These changes don't change anything about the complexity of the algorithms, but use some easy shortcuts or modifications to cut down some overhead.
The first change, which incrementally removes the constraints from the set we're iterating over probably introduces some overhead for small to medium sized constraint sets, but it's not big enough for me to observe it in any project I tested against (not that many though).
Though most other crates probably won't improve much at all, because huge matches aren't that common, the changes seemed simple enough for me to make them.
Ref #55528
cc unicode-rs/unicode-normalization#29
r? @nikomatsakis
save-analysis: Get path def from parent in case there's no def for the path itself.
This fixes#57462.
The relevant part from the hir type collector is:
```
DEBUG 2019-01-09T15:42:58Z: rustc::hir::map::collector: hir_map: NodeId(32) => Entry { parent: NodeId(33), dep_node: 4294967040, node: Expr(expr(32: <Foo>::new)) }
DEBUG 2019-01-09T15:42:58Z: rustc::hir::map::collector: hir_map: NodeId(48) => Entry { parent: NodeId(32), dep_node: 4294967040, node: Ty(type(Foo)) }
DEBUG 2019-01-09T15:42:58Z: rustc::hir::map::collector: hir_map: NodeId(30) => Entry { parent: NodeId(48), dep_node: 4294967040, node: PathSegment(PathSegment { ident: Foo#0, id: Some(NodeId(30)), def: Some(Err), args: None, infer_types: true }) }
DEBUG 2019-01-09T15:42:58Z: rustc::hir::map::collector: hir_map: NodeId(31) => Entry { parent: NodeId(32), dep_node: 4294967040, node: PathSegment(PathSegment { ident: new#0, id: Some(NodeId(31)), def: Some(Err), args: None, infer_types: true }) }
```
We have the right ID when looking for NodeId(31) and try with NodeId(32) (which
is the right thing to look for) from get_path_data. But not when we look from `write_sub_paths_truncated`
Basically process_path takes an id which is always the parent, and that we
fall back to in get_path_data(), so we get the right result for the last path
segment, but not for the other segments that get written to from
write_sub_paths_truncated.
I think we can stop passing the explicit `id` around to get_path_data as a followup.
std: Render large exit codes as hex on Windows
On Windows process exit codes are never signals but rather always 32-bit
integers. Most faults like segfaults and such end up having large
integers used to represent them, like STATUS_ACCESS_VIOLATION being
0xC0000005. Currently, however, when an `ExitStatus` is printed this
ends up getting rendered as 3221225477 which is somewhat more difficult
to debug.
This commit adds a branch in `Display for ExitStatus` on Windows which
handles exit statuses where the high bit is set and prints those exit
statuses as hex instead of with decimals. This will hopefully preserve
the current display for small exit statuses (like `exit code: 22`), but
assist in quickly debugging segfaults/access violations/etc. I've
found at least that the hex codes are easier to search for than decimal.
I wasn't able to find any official documentation saying that all system
exit codes have the high bit set, but I figure it's a good enough
heuristic for now.
Change `String` to `&'static str` in `ParseResult::Failure`.
This avoids 770,000 allocations when compiling the `html5ever`
benchmark, reducing instruction counts by up to 2%.
save-analysis: use a fallback when access levels couldn't be computed
Fixing an RLS regression I introduced in https://github.com/rust-lang/rust/pull/57343😢
I missed a case where we get [called back with analysis when type checking fails](9d54812829/src/librustc_driver/driver.rs (L1264)). Since privacy checking normally is done afterwards, when we execute the `privacy_access_levels` query inside the save_analysis callback we'll calculate it for the first time and since typeck info isn't complete, we'll crash there.
Double-checked locally and it seems to have fixed the problem.
r? @nikomatsakis
Don't actually create a full MIR stack frame when not needed
r? @dotdash
This should significantly reduce overhead during const propagation and reduce overhead *after* copy propagation (cc https://github.com/rust-lang/rust/issues/36673)
