Don't emit the same compiler diagnostic twice.
This PR makes the compiler filter out diagnostic messages that have already been emitted during the same compilation session.
MIR-borrowck: moves of prefixes invalidate uses too
I overlooked the fact that when we check if a path is moved, we need to check for interference between the (shallow) prefixes and the use in question.
~~Long term, we may want to revise how this computation is done. For example, it might be better to represent the set of invalidated prefixes in the dataflow computation (the `maybe_uninitialized` dataflow), and thus avoid one of the loops in the code here.~~
* Update: I was wrong in my original recollection of the dataflow code, which actually does the right thing, in terms of precisely tracking substructure initialization and movement.
Fix#44833
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Update: The initial version of this PR's description (and the code as well) erroneously focused on supporting prefixes. ~~But the two main cases of interest are: 1. the *shallow* prefixes, and 2. the deref-free prefix built off a local (if the lvalue is indeed built off a local)~~
Update 2: The main cases of interest are in fact: 1. the nearest prefix with a MovePath, and 2. the suffixes.
MIR borrowck: print lvalues in error messages in the same way that the AST borrowck
Fix#44974
- Print fields with `.name` rather than `.<num>`
- Autoderef values if followed by a field or an index
- Output `[..]` when borrowing inside a slice
(There are other tests that this PR also improves, but were not
completely synchronized. I chose to wait until later to pull those
into the `revisions: ast mir` testing pattern; later being either when
they *are* synchronized, or in some PR where we migrate all borrowck
tests, regardless of whether MIR-borrowck is "finished" for them or
not.)
Previously the constant index was reported as `[x of y]` or `[-x of y]` where
`x` was the offset and `y` the minimum length of the slice. The minus sign
wasn't in the right case since for `&[_, x, .., _, _]`, the error reported was
`[-1 of 4]`, and for `&[_, _, .., x, _]`, the error reported was `[2 of 4]`.
This commit fixes the sign so that the indexes 1 and -2 are reported, and
remove the ` of y` part of the message to make it more succinct.
This commit tests *just* the subset of the tests that were previously
ICE'ing and where now AST- and MIR-borrowck both match in terms of the
errors they report.
In other words: there remain *other* tests that previously ICE'd, and
now no longer ICE, but their remains a divergence between the errors
reported by AST-borrowck and by MIR-borrowck.
In some cases, we give multiple primary spans, in which case we would
report one `//~` annotation per primary span. That was very confusing
because these things are reported to the user as a single error.
UI tests would be better here.
This converts all of borrowck's `mut` suggestions to a new
`mc::ImmutabilityBlame` API instead of the current mix of various hacks.
Fixes#35937.
Fixes#40823.
Most of the Rust community agrees that the vec! macro is clearer when
called using square brackets [] instead of regular brackets (). Most of
these ocurrences are from before macros allowed using different types of
brackets.
There is one left unchanged in a pretty-print test, as the pretty
printer still wants it to have regular brackets.
