There is now a CoreEmitter that everything desugars to, but without
losing any information. Also remove RenderSpan::FileLine. This lets the
rustc_driver tests build.
The extra filename and line was mainly there to keep the indentation
relative to the main snippet; now that this doesn't include
filename/line-number as a prefix, it is distracted.
This API pulls the "expected type foo, found type bar" out after the
main snippet. There are some other places where it makes sense, but this
is a start.
Major changes:
- Remove old snippet rendering code and use the new stuff.
- Introduce `span_label` method to add a label
- Remove EndSpan mode and replace with a fn to get the last
character of a span.
- Stop using `Option<MultiSpan>` and just use an empty `MultiSpan`
- and probably a bunch of other stuff :)
MultiSpan model is now:
- set of primary spans
- set of span+label pairs
Primary spans render with `^^^`, secondary spans with `---`.
Labels are placed next to the `^^^` or `---` marker as appropriate.
There was no span available in the cast function, but we need to infer the `x` in `x as char` to `u8`.
The spans are now removed from all functions using `infer` and instead added in `eval_const_expr_partial`
[MIR] Handle coercion casts properly when building the MIR
Coercion casts (`expr as T` where the type of `expr` can be coerced to
`T`) are essentially no-ops, as the actual work is done by a coercion.
Previously a check for type equality was used to avoid emitting the
redundant cast in the MIR, but this failed for coercion casts of
function items that had lifetime parameters. The MIR trans code doesn't
handle `FnPtr -> FnPtr` casts and produced an error.
Also fixes a bug with type ascription expressions not having any
adjustments applied.
Fixes#33295
/cc @eddyb
Current description of `std::mem::size_of` is ambiguous, and the
`std::intrinsics::size_of` description incorrectly defines size
as the number of bytes necessary to exactly overwrite a value,
not including the padding between elements necessary in a vector
or structure.
Current code leads to messages like "... use a \xHH escape: \u{e4}"
which is confusing.
The printed span already points to the offending character, which
should be enough to identify the non-ASCII problem.
Fixes: #29088
This is curiously missing from both the short message and this
long diagnostic.
Refs #31573 (not sure if it should be considered "fixed" as the
short message still only refers to extern crates).
In situations where the value of the last expression must be inferred,
rustc will not emit the "you might need to remove the semicolon" warning,
so at least note this in the extended description.
Fixes: #30497
resolve: improve diagnostics and lay groundwork for resolving before ast->hir
This PR improves diagnostics in `resolve` and lays some groundwork for resolving before ast->hir.
More specifically,
- It removes an API in `resolve` intended for external refactoring tools (see #27493) that appears not to be in active use. The API is incompatible with resolving before ast->hir, but could be rewritten in a more compatible and less intrusive way.
- It improves the diagnostics for pattern bindings that conflict with `const`s.
- It improves the diagnostics for modules used as expressions (fixes#33186).
- It refactors away some uses of the hir map, which is unavavailable before ast->hir lowering.
r? @eddyb
Remove the requirement that ast->hir lowering be reproducible
This PR changes the ast->hir lowerer to be non-reproducible, and it removes the lowering context's id cache.
If the `hir` of an `ast` node needs to be reproduced, we can use the hir map instead of the lowerer -- for example, `tcx.map.expect_expr(expr.id)` instead of `lower_expr(lcx, expr)`.
r? @nrc
