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FIx ICE on wf check for foreign fns
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JohnTitor committed Dec 31, 2020
1 parent 507bff9 commit 7008911
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Showing 4 changed files with 50 additions and 1 deletion.
8 changes: 8 additions & 0 deletions compiler/rustc_infer/src/infer/error_reporting/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -153,6 +153,7 @@ fn msg_span_from_early_bound_and_free_regions(
Some(Node::Item(it)) => item_scope_tag(&it),
Some(Node::TraitItem(it)) => trait_item_scope_tag(&it),
Some(Node::ImplItem(it)) => impl_item_scope_tag(&it),
Some(Node::ForeignItem(it)) => foreign_item_scope_tag(&it),
_ => unreachable!(),
};
let (prefix, span) = match *region {
Expand Down Expand Up @@ -233,6 +234,13 @@ fn impl_item_scope_tag(item: &hir::ImplItem<'_>) -> &'static str {
}
}

fn foreign_item_scope_tag(item: &hir::ForeignItem<'_>) -> &'static str {
match item.kind {
hir::ForeignItemKind::Fn(..) => "method body",
hir::ForeignItemKind::Static(..) | hir::ForeignItemKind::Type => "associated item",
}
}

fn explain_span(tcx: TyCtxt<'tcx>, heading: &str, span: Span) -> (String, Option<Span>) {
let lo = tcx.sess.source_map().lookup_char_pos(span.lo());
(format!("the {} at {}:{}", heading, lo.line, lo.col.to_usize() + 1), Some(span))
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2 changes: 1 addition & 1 deletion compiler/rustc_typeck/src/check/wfcheck.rs
Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,7 @@ impl<'tcx> CheckWfFcxBuilder<'tcx> {
let fcx = FnCtxt::new(&inh, param_env, id);
if !inh.tcx.features().trivial_bounds {
// As predicates are cached rather than obligations, this
// needsto be called first so that they are checked with an
// needs to be called first so that they are checked with an
// empty `param_env`.
check_false_global_bounds(&fcx, span, id);
}
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17 changes: 17 additions & 0 deletions src/test/ui/wf/wf-in-foreign-fn-decls-issue-80468.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
// Regression test for #80468.

#![crate_type = "lib"]

pub trait Trait {}

#[repr(transparent)]
pub struct Wrapper<T: Trait>(T);

#[repr(transparent)]
pub struct Ref<'a>(&'a u8);

impl Trait for Ref {} //~ ERROR: implicit elided lifetime not allowed here

extern "C" {
pub fn repro(_: Wrapper<Ref>); //~ ERROR: mismatched types
}
24 changes: 24 additions & 0 deletions src/test/ui/wf/wf-in-foreign-fn-decls-issue-80468.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,24 @@
error[E0726]: implicit elided lifetime not allowed here
--> $DIR/wf-in-foreign-fn-decls-issue-80468.rs:13:16
|
LL | impl Trait for Ref {}
| ^^^- help: indicate the anonymous lifetime: `<'_>`

error[E0308]: mismatched types
--> $DIR/wf-in-foreign-fn-decls-issue-80468.rs:16:21
|
LL | pub fn repro(_: Wrapper<Ref>);
| ^^^^^^^^^^^^ lifetime mismatch
|
= note: expected trait `Trait`
found trait `Trait`
note: the anonymous lifetime #1 defined on the method body at 16:5...
--> $DIR/wf-in-foreign-fn-decls-issue-80468.rs:16:5
|
LL | pub fn repro(_: Wrapper<Ref>);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: ...does not necessarily outlive the static lifetime

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0308`.

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