diff --git a/src/librustc/middle/infer/mod.rs b/src/librustc/middle/infer/mod.rs index 3eca4624bc17d..e671dd73431e6 100644 --- a/src/librustc/middle/infer/mod.rs +++ b/src/librustc/middle/infer/mod.rs @@ -1120,11 +1120,15 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { .map(|method| resolve_ty(method.ty))) } + pub fn errors_since_creation(&self) -> bool { + self.tcx.sess.err_count() - self.err_count_on_creation != 0 + } + pub fn node_type(&self, id: ast::NodeId) -> Ty<'tcx> { match self.tables.borrow().node_types.get(&id) { Some(&t) => t, // FIXME - None if self.tcx.sess.err_count() - self.err_count_on_creation != 0 => + None if self.errors_since_creation() => self.tcx.types.err, None => { self.tcx.sess.bug( @@ -1147,7 +1151,14 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { free_regions: &FreeRegionMap, subject_node_id: ast::NodeId) { let errors = self.region_vars.resolve_regions(free_regions, subject_node_id); - self.report_region_errors(&errors); // see error_reporting.rs + if !self.errors_since_creation() { + // As a heuristic, just skip reporting region errors + // altogether if other errors have been reported while + // this infcx was in use. This is totally hokey but + // otherwise we have a hard time separating legit region + // errors from silly ones. + self.report_region_errors(&errors); // see error_reporting.rs + } } pub fn ty_to_string(&self, t: Ty<'tcx>) -> String { diff --git a/src/test/compile-fail/issue-30580.rs b/src/test/compile-fail/issue-30580.rs new file mode 100644 index 0000000000000..88d4aef6d9ddc --- /dev/null +++ b/src/test/compile-fail/issue-30580.rs @@ -0,0 +1,27 @@ +// Copyright 2012 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// Test that we do not see uninformative region-related errors +// when we get some basic type-checking failure. See #30580. + +pub struct Foo { a: u32 } +pub struct Pass<'a, 'tcx: 'a>(&'a mut &'a (), &'a &'tcx ()); + +impl<'a, 'tcx> Pass<'a, 'tcx> +{ + pub fn tcx(&self) -> &'a &'tcx () { self.1 } + fn lol(&mut self, b: &Foo) + { + b.c; //~ ERROR no field with that name was found + self.tcx(); + } +} + +fn main() {}