[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
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.
(The commit prior to this actual passes our test suite, "thanks"
to #55695. But since I am aware of that bug, I took advantage of it
in choosing how to order my commit series...)
(I opted to rely on compare-mode=nll rather than opt into
`#![feature(nll)]`, mostly to make it easy to observe the interesting
differences between the AST-borrwock diagnostic and the NLL one.)
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
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.
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.
Fixes#51947.
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.
