bjoernager/rust
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pretty: trim paths of unique symbols

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If a symbol name can only be imported from one place for a type, and
as long as it was not glob-imported anywhere in the current crate, we
can trim its printed path and print only the name.

This has wide implications on error messages with types, for example,
shortening `std::vec::Vec` to just `Vec`, as long as there is no other
`Vec` importable anywhere.

This adds a new '-Z trim-diagnostic-paths=false' option to control this
feature.

On the good path, with no diagnosis printed, we should try to avoid
issuing this query, so we need to prevent trimmed_def_paths query on
several cases.

This change also relies on a previous commit that differentiates
between `Debug` and `Display` on various rustc types, where the latter
is trimmed and presented to the user and the former is not.
This commit is contained in:
Dan Aloni 2020-09-02 10:40:56 +03:00
parent 7b2deb5628
commit 07e7823c01
1325 changed files with 4806 additions and 4546 deletions
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27
compiler/rustc_lint/src/context.rs
View file

@ -31,6 +31,7 @@ use rustc_middle::lint::LintDiagnosticBuilder;
use rustc_middle::middle::privacy::AccessLevels;
use rustc_middle::middle::stability;
use rustc_middle::ty::layout::{LayoutError, TyAndLayout};
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::{self, print::Printer, subst::GenericArg, Ty, TyCtxt};
use rustc_session::lint::{add_elided_lifetime_in_path_suggestion, BuiltinLintDiagnostics};
use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintBuffer, LintId};
@ -795,10 +796,12 @@ impl<'tcx> LateContext<'tcx> {
}
// This shouldn't ever be needed, but just in case:
Ok(vec![match trait_ref {
Some(trait_ref) => Symbol::intern(&format!("{:?}", trait_ref)),
None => Symbol::intern(&format!("<{}>", self_ty)),
}])
with_no_trimmed_paths(|| {
Ok(vec![match trait_ref {
Some(trait_ref) => Symbol::intern(&format!("{:?}", trait_ref)),
None => Symbol::intern(&format!("<{}>", self_ty)),
}])
})
}
fn path_append_impl(
@ -812,12 +815,16 @@ impl<'tcx> LateContext<'tcx> {
// This shouldn't ever be needed, but just in case:
path.push(match trait_ref {
Some(trait_ref) => Symbol::intern(&format!(
"<impl {} for {}>",
trait_ref.print_only_trait_path(),
self_ty
)),
None => Symbol::intern(&format!("<impl {}>", self_ty)),
Some(trait_ref) => with_no_trimmed_paths(|| {
Symbol::intern(&format!(
"<impl {} for {}>",
trait_ref.print_only_trait_path(),
self_ty
))
}),
None => {
with_no_trimmed_paths(|| Symbol::intern(&format!("<impl {}>", self_ty)))
}
});
Ok(path)