diff options
Diffstat (limited to 'compiler/rustc_span/src/lib.rs')
| -rw-r--r-- | compiler/rustc_span/src/lib.rs | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs index 9c5469f635f..032ae73bbf3 100644 --- a/compiler/rustc_span/src/lib.rs +++ b/compiler/rustc_span/src/lib.rs @@ -25,6 +25,9 @@ #[macro_use] extern crate rustc_macros; +#[macro_use] +extern crate tracing; + use rustc_data_structures::AtomicRef; use rustc_macros::HashStable_Generic; use rustc_serialize::{Decodable, Decoder, Encodable, Encoder}; @@ -782,13 +785,30 @@ impl Span { /// ^^^^^^^^^^^^^^^^^ /// ``` pub fn until(self, end: Span) -> Span { - let span = self.data(); - let end = end.data(); + // Most of this function's body is copied from `to`. + // We can't just do `self.to(end.shrink_to_lo())`, + // because to also does some magic where it uses min/max so + // it can handle overlapping spans. Some advanced mis-use of + // `until` with different ctxts makes this visible. + let span_data = self.data(); + let end_data = end.data(); + // FIXME(jseyfried): `self.ctxt` should always equal `end.ctxt` here (cf. issue #23480). + // Return the macro span on its own to avoid weird diagnostic output. It is preferable to + // have an incomplete span than a completely nonsensical one. + if span_data.ctxt != end_data.ctxt { + if span_data.ctxt == SyntaxContext::root() { + return end; + } else if end_data.ctxt == SyntaxContext::root() { + return self; + } + // Both spans fall within a macro. + // FIXME(estebank): check if it is the *same* macro. + } Span::new( - span.lo, - end.lo, - if end.ctxt == SyntaxContext::root() { end.ctxt } else { span.ctxt }, - if span.parent == end.parent { span.parent } else { None }, + span_data.lo, + end_data.lo, + if end_data.ctxt == SyntaxContext::root() { end_data.ctxt } else { span_data.ctxt }, + if span_data.parent == end_data.parent { span_data.parent } else { None }, ) } |