From 6c14aad58e65c9c50faa45ed88369c5c72d6d0d7 Mon Sep 17 00:00:00 2001 From: Aaron Hill Date: Sun, 31 Jan 2021 15:21:28 -0500 Subject: Improve handling of spans around macro result parse errors Fixes #81543 After we expand a macro, we try to parse the resulting tokens as a AST node. This commit makes several improvements to how we handle spans when an error occurs: * Only ovewrite the original `Span` if it's a dummy span. This preserves a more-specific span if one is available. * Use `self.prev_token` instead of `self.token` when emitting an error message after encountering EOF, since an EOF token always has a dummy span * Make `SourceMap::next_point` leave dummy spans unused. A dummy span does not have a logical 'next point', since it's a zero-length span. Re-using the span span preserves its 'dummy-ness' for other checks --- compiler/rustc_parse/src/parser/diagnostics.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'compiler/rustc_parse/src/parser') diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index f2fcce5c226..5512e849c45 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -1104,7 +1104,7 @@ impl<'a> Parser<'a> { let (prev_sp, sp) = match (&self.token.kind, self.subparser_name) { // Point at the end of the macro call when reaching end of macro arguments. (token::Eof, Some(_)) => { - let sp = self.sess.source_map().next_point(self.token.span); + let sp = self.sess.source_map().next_point(self.prev_token.span); (sp, sp) } // We don't want to point at the following span after DUMMY_SP. @@ -1721,7 +1721,7 @@ impl<'a> Parser<'a> { pub(super) fn expected_expression_found(&self) -> DiagnosticBuilder<'a> { let (span, msg) = match (&self.token.kind, self.subparser_name) { (&token::Eof, Some(origin)) => { - let sp = self.sess.source_map().next_point(self.token.span); + let sp = self.sess.source_map().next_point(self.prev_token.span); (sp, format!("expected expression, found end of {}", origin)) } _ => ( -- cgit 1.4.1-3-g733a5