Encode spans relative to the enclosing item
The aim of this PR is to avoid recomputing queries when code is moved without modification.
MCP at https://github.com/rust-lang/compiler-team/issues/443
This is achieved by :
1. storing the HIR owner LocalDefId information inside the span;
2. encoding and decoding spans relative to the enclosing item in the incremental on-disk cache;
3. marking a dependency to the `source_span(LocalDefId)` query when we translate a span from the short (`Span`) representation to its explicit (`SpanData`) representation.
Since all client code uses `Span`, step 3 ensures that all manipulations
of span byte positions actually create the dependency edge between
the caller and the `source_span(LocalDefId)`.
This query return the actual absolute span of the parent item.
As a consequence, any source code motion that changes the absolute byte position of a node will either:
- modify the distance to the parent's beginning, so change the relative span's hash;
- dirty `source_span`, and trigger the incremental recomputation of all code that
depends on the span's absolute byte position.
With this scheme, I believe the dependency tracking to be accurate.
For the moment, the spans are marked during lowering.
I'd rather do this during def-collection,
but the AST MutVisitor is not practical enough just yet.
The only difference is that we attach macro-expanded spans
to their expansion point instead of the macro itself.
Fix result order for `manual_split_once` when `rsplitn` is used
fixes: #7656
changelog: Fix result order for `manual_split_once` when `rsplitn` is used
rustc: use more correct span data in for loop desugaring
Fixes#82462
Before:
help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
|
LL | for x in DroppingSlice(&*v).iter(); {
| +
After:
help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
|
LL | };
| +
This seems like a reasonable fix: since the desugared "expr_drop_temps_mut" contains the entire desugared loop construct, its span should contain the entire loop construct as well.
Backport remerge
This is to keep the backported commit in the repository before force pushing the new beta branch.
r? `@ghost`
changelog: none
(literally none)
Add new lint `iter_not_returning_iterator`
Add new lint [`iter_not_returning_iterator`] to detect method `iter()` or `iter_mut()` returning a type not implementing `Iterator`
changelog: Add new lint [`iter_not_returning_iterator`]
Allow giving reasons for `disallowed_methods`
Fixes#7609.
This permits writing the config for `disallowed-methods` as either a list of strings (like before) or a list of tables, where each table gives the path to the disallowed method and an optional reason for why the method is disallowed.
changelog: Allow giving reasons for [`disallowed_methods`]
`mut_range_bound` check for immediate break after mutation
closes#7532
`mut_range_bound` ignores mutation on range bounds that is placed immediately before break. Still warns if the break is not always reachable.
changelog: [`mut_range_bound`] ignore range bound mutations before immediate break
