Warn on pointless #[derive] in more places
This fixes the regression in #49934 and ensures that unused `#[derive]` invocations on statements, expressions and generic type parameters survive to trip the `unused_attributes` lint. There is a separate warning hardcoded for `#[derive]` on macro invocations since linting (even the early-lint pass) occurs after expansion. This also adds regression tests for some nodes that were already warning properly.
closes#49934
This fixes the regression in #49934 and ensures that unused `#[derive]`s on statements, expressions and generic type parameters survive to trip the `unused_attributes` lint. For `#[derive]` on macro invocations it has a hardcoded warning since linting occurs after expansion. This also adds regression testing for some nodes that were already warning properly.
closes#49934
Fix ICE #48984
* ~~fbf6423 The tail type was not normalized.~~
* d0839d5680 The method had a wrong assumption that something whose parent is a trait is an associated item. Fixes#48984.
Previously the features specified to LLVM via `-C target-feature` were only
reflected in the `TargetMachine` but this change *also* reflects these and the
base features inside each function itself. This change matches clang and...
Closesrust-lang-nursery/stdsimd#427
Added warning for unused arithmetic expressions
The compiler now displays a warning when a binary arithmetic operation is evaluated but not used. This resolves#50124 by following the instructions outlined in the issue. The changes are as follows:
- Added new pattern matching for unused arithmetic expressions in `src/librustc_lint/unused.rs`
- Added `#[must_use]` attributes to the binary operation methods in `src/libcore/internal_macros.rs`
- Added `#[must_use]` attributes to the non-assigning binary operators in `src/libcore/ops/arith.rs`
Access individual fields of tuples, closures and generators on drop.
Fixes#48623, by extending the change in #47917 to closures. Also does this for tuples and generators for consistency.
Enums are unchanged because there is now way to borrow `*enum.field` without borrowing `enum.field` at the moment, so any error would be reported when the enum goes out of scope. Unions aren't changed because unions they don't automatically drop their fields.
r? @nikomatsakis
Rollup of 7 pull requests
Successful merges:
- #49707 (Add "the Rustc book")
- #50222 (Bump bootstrap compiler to 2018-04-24)
- #50227 (Fix ICE with erroneous `impl Trait` in a trait impl)
- #50229 (Add setting to go to item if there is only one result)
- #50231 (Add more doc aliases)
- #50246 (Make dump_{alloc,allocs,local}() no-ops when tracing is disabled.)
- #49894 (Rename InternedString to LocalInternedString and introduce a new thread-safe InternedString)
Failed merges:
Create a canonical trait query for `evaluate_obligation`
This builds on the canonical query machinery introduced in #48411 to introduce a new canonical trait query for `evaluate_obligation` in the trait selector. Also ports most callers of the original `evaluate_obligation` to the new system (except in coherence, which requires support for intercrate mode). Closes#48537.
r? @nikomatsakis
drop elaboration should reveal all
This used to happen implicitly through the normalization function; but we now keep the param-env as is, which seems less surprising.
cc #49685
r? @eddyb
