[regression - rust2018]: unused_mut lint false positives on nightly
Fixes#55344.
This commit filters out locals that have never been initialized for
consideration in the `unused_mut` lint.
This is intended to detect when the statement that would have
initialized the local was removed as unreachable code. In these cases,
we would not want to lint. This is the same behaviour as the AST borrow
checker.
This is achieved by taking advantage of an existing pass over the MIR
for the `unused_mut` lint and creating a set of those locals that were
never initialized.
r? @pnkfelix
Avoid panic when matching function call
Fix#55718
This bug is introduced by #53751. The original code checked `Def::AssociatedConst(..) | Def::Method(..)` before `pat_ty.no_bound_vars().expect("expected fn type")`. But somehow I exchanged the sequence carelessly. Sorry about that.
r? @petrochenkov
Consume optimization fuel from the MIR inliner
This makes it easier to debug mis-optimizations that occur during
inlining. Thanks to @nikomatsakis for the suggestion!
Sidestep link error from rustfix'ed code by using a *defined* static.
As a drive-by, added `-g` to the compile-flags so that the test more
reliably fails to compile when the extern static in question is *not*
provided. (I.e. this is making the test more robust in the face of
potential future revisions.)
Fix#54388.
rustc: Delete grouping logic from the musl target
This commit deletes the injection of `-(` and `-)` options to the linker
for the musl targets. This actually causes problems today on nightly if
you execute:
$ echo 'fn main() {}' >> foo.rs
$ rustc --target x86_64-unknown-linux-musl -C panic=abort
you get a linker error about "cannot nest groups". This comes about
because rustc injects its own `--start-group` and `--end-group`
variables which clash with the outer `-(` and `-)` variables. It's not
entirely clear to me why this doesn't affect the musl target by default
(in `-C panic=unwind` mode).
The compiler's own injection of `--start-group` and `--end-group` should
solve the issues mentioned in the comment for injecting `-(` and `-)` as
well.
Support memcpy/memmove with differing src/dst alignment
If LLVM 7 is used, generate memcpy/memmove with differing src/dst alignment. I've added new FFI functions to construct these through the builder API, which is more convenient than dealing with differing intrinsic signatures depending on the LLVM version.
Fixes#49740.
Rollup of 14 pull requests
Successful merges:
- #55377 (Slight copy-editing for `std::cell::Cell` docs)
- #55441 (Remove unused re import in gdb_rust_pretty_printing)
- #55453 (Choose predicates without inference variables over those with them)
- #55495 (Don't print opt fuel messages to stdout because it breaks Rustbuild)
- #55501 (Make `process_obligations`' computation of `completed` optional.)
- #55510 (Fix feature gate only being checked on first repr attr.)
- #55609 (Run name-anon-globals after LTO passes as well)
- #55645 (do not print wrapping ranges like normal ranges in validity diagnostics)
- #55688 (Standardised names and location of ui issue tests)
- #55692 (-C remark: fix incorrect warning about requiring "--debuginfo" instead of "-C debuginfo=n")
- #55702 (Add `aarch64-pc-windows-msvc` to deployed targets)
- #55728 (Update lldb)
- #55730 (Use trait impl method span when type param mismatch is due to impl Trait)
- #55734 (refactor: use shorthand fields)
This commit filters out locals that have never been initialized for
consideration in the `unused_mut` lint.
This is intended to detect when the statement that would have
initialized the local was removed as unreachable code. In these cases,
we would not want to lint. This is the same behaviour as the AST borrow
checker.
This is achieved by taking advantage of an existing pass over the MIR
for the `unused_mut` lint and creating a set of those locals that were
never initialized.
I also added `// skip-codegen` to each one, to address potential concerns
that this change would otherwise slow down our test suite spending time
generating code for files that are really just meant to be checks of
compiler diagnostics.
(However, I will say: My preference is to not use `// skip-codegen` if
one can avoid it. We can use all the testing of how we drive LLVM that
we can get...)
(Updated post rebase.)
This test specifically notes that it does not want to invoke the
linker, due to the way it (IMO weakly) exercises the `#[link=...]`
attribute.
In any case, removing the the `#[rustc_error]` here uncovered an
"invalid windows subsystem" error that was previously not included in
the transcript of diagnostic output. So that's a step forward, (right?).
Run name-anon-globals after LTO passes as well
If we're going to emit bitcode (through ThinLTOBuffer), then we need to ensure that anon globals are named. This was already done after optimization passes, but also has to happen after LTO passes, as we always emit the final result in a ThinLTO-compatible manner.
I added the test as `run-make`. The important bit is that we emit bitcode in some way (e.g. `--crate-type rlib` or `--emit=llvm-bc`). Please tell me if there is a better way to test for that.
Fixes#51947
Make `process_obligations`' computation of `completed` optional.
It's only used in tests.
This reduces instruction counts on several benchmarks by 0.5--1%.
Don't print opt fuel messages to stdout because it breaks Rustbuild
Rustbuild passes `--message-format json` to the compiler invocations
which causes JSON to be emitted on stdout. Printing optimization fuel
messages to stdout breaks the json and causes Rustbuild to fail.
Work around this by emitting optimization fuel related messages on
stderr instead.
Choose predicates without inference variables over those with them
Fixes#54705
When constructing synthetic auto trait impls, we may come across
multiple predicates involving the same type, trait, and substitutions.
Since we can only display one of these, we pick the one with the 'most
strict' lifetime paramters. This ensures that the impl we render the
user is actually valid (that is, a struct matching that impl will
actually implement the auto trait in question).
This commit exapnds the definition of 'more strict' to take into account
inference variables. We always choose a predicate without inference
variables over a predicate with inference variables.
