diff options
| -rw-r--r-- | src/librustc/traits/error_reporting.rs | 18 | ||||
| -rw-r--r-- | src/test/ui/suggestions/for-c-in-str.rs | 21 | ||||
| -rw-r--r-- | src/test/ui/suggestions/for-c-in-str.stderr | 11 |
3 files changed, 50 insertions, 0 deletions
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs index e649f1b49df..61456b3b003 100644 --- a/src/librustc/traits/error_reporting.rs +++ b/src/librustc/traits/error_reporting.rs @@ -551,6 +551,24 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { let OnUnimplementedNote { message, label } = self.on_unimplemented_note(trait_ref, obligation); let have_alt_message = message.is_some() || label.is_some(); + let span = match self.tcx.sess.codemap().span_to_snippet(span) { + Ok(ref s) if s.starts_with("for ") => { + // On for loops, this error is caused by the element being iterated + // on, but the span points at the entire for loop. Instead of: + // + // / for c in "asdf" { + // | ... + // | } + // |_^ `&str` is not an iterator + // + // lets point at: + // + // for c in "asdf" { + // ^^^^^^^^^^^^^^^ `&str` is not an iterator + self.tcx.sess.codemap().span_until_char(span, '{') + } + _ => span, + }; let mut err = struct_span_err!( self.tcx.sess, diff --git a/src/test/ui/suggestions/for-c-in-str.rs b/src/test/ui/suggestions/for-c-in-str.rs new file mode 100644 index 00000000000..011886e8073 --- /dev/null +++ b/src/test/ui/suggestions/for-c-in-str.rs @@ -0,0 +1,21 @@ +// Copyright 2018 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 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// E0277 should point exclusively at line 14, not the entire for loop span + +fn main() { + for c in "asdf" { + //~^ ERROR the trait bound `&str: std::iter::Iterator` is not satisfied + //~| NOTE `&str` is not an iterator + //~| HELP the trait `std::iter::Iterator` is not implemented for `&str` + //~| NOTE required by `std::iter::IntoIterator::into_iter` + println!(""); + } +} diff --git a/src/test/ui/suggestions/for-c-in-str.stderr b/src/test/ui/suggestions/for-c-in-str.stderr new file mode 100644 index 00000000000..e99a7d7fe55 --- /dev/null +++ b/src/test/ui/suggestions/for-c-in-str.stderr @@ -0,0 +1,11 @@ +error[E0277]: the trait bound `&str: std::iter::Iterator` is not satisfied + --> $DIR/for-c-in-str.rs:14:5 + | +14 | for c in "asdf" { + | ^^^^^^^^^^^^^^^ `&str` is not an iterator; maybe try calling `.iter()` or a similar method + | + = help: the trait `std::iter::Iterator` is not implemented for `&str` + = note: required by `std::iter::IntoIterator::into_iter` + +error: aborting due to previous error + |