From eb0fcc5ad1f8e622c942334658ae9d2a9fd2203e Mon Sep 17 00:00:00 2001 From: yukang Date: Sun, 6 Aug 2023 22:28:14 +0800 Subject: [PATCH] refactor on span_look_ahead --- .../rustc_resolve/src/late/diagnostics.rs | 20 +++++++------- compiler/rustc_span/src/source_map.rs | 15 +++++------ .../src/traits/error_reporting/suggestions.rs | 26 +++++++++---------- 3 files changed, 28 insertions(+), 33 deletions(-) diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index 867d7c6f00329..9edcb5255b204 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -1008,7 +1008,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> { span: Span, ) { if let Some((trait_ref, self_ty)) = - self.diagnostic_metadata.currently_processing_impl_trait.clone() + self.diagnostic_metadata.currently_processing_impl_trait.clone() && let TyKind::Path(_, self_ty_path) = &self_ty.kind && let PathResult::Module(ModuleOrUniformRoot::Module(module)) = self.resolve_path(&Segment::from_path(self_ty_path), Some(TypeNS), None) @@ -1217,15 +1217,15 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> { // where a brace being opened means a block is being started. Look // ahead for the next text to see if `span` is followed by a `{`. let sm = self.r.tcx.sess.source_map(); - let sp = sm.span_look_ahead(span, None, Some(50)); - let followed_by_brace = matches!(sm.span_to_snippet(sp), Ok(ref snippet) if snippet == "{"); - // In case this could be a struct literal that needs to be surrounded - // by parentheses, find the appropriate span. - let closing_span = sm.span_look_ahead(span, Some("}"), Some(50)); - let closing_brace: Option = sm - .span_to_snippet(closing_span) - .map_or(None, |s| if s == "}" { Some(span.to(closing_span)) } else { None }); - (followed_by_brace, closing_brace) + if let Some(followed_brace_span) = sm.span_look_ahead(span, "{", Some(50)) { + // In case this could be a struct literal that needs to be surrounded + // by parentheses, find the appropriate span. + let close_brace_span = sm.span_look_ahead(followed_brace_span, "}", Some(50)); + let closing_brace = close_brace_span.map(|sp| span.to(sp)); + (true, closing_brace) + } else { + (false, None) + } } /// Provides context-dependent help for errors reported by the `smart_resolve_path_fragment` diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs index 86716da1712fb..983b2ab04a4ae 100644 --- a/compiler/rustc_span/src/source_map.rs +++ b/compiler/rustc_span/src/source_map.rs @@ -973,24 +973,21 @@ impl SourceMap { Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt(), None) } - /// Returns a new span to check next none-whitespace character or some specified expected character - /// If `expect` is none, the first span of non-whitespace character is returned. - /// If `expect` presented, the first span of the character `expect` is returned - /// Otherwise, the span reached to limit is returned. - pub fn span_look_ahead(&self, span: Span, expect: Option<&str>, limit: Option) -> Span { + /// Check whether span is followed by some specified expected string in limit scope + pub fn span_look_ahead(&self, span: Span, expect: &str, limit: Option) -> Option { let mut sp = span; for _ in 0..limit.unwrap_or(100_usize) { sp = self.next_point(sp); if let Ok(ref snippet) = self.span_to_snippet(sp) { - if expect.is_some_and(|es| snippet == es) { - break; + if snippet == expect { + return Some(sp); } - if expect.is_none() && snippet.chars().any(|c| !c.is_whitespace()) { + if snippet.chars().any(|c| !c.is_whitespace()) { break; } } } - sp + None } /// Finds the width of the character, either before or after the end of provided span, diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index 31f70bbd34dec..e62be1adbcaae 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -1428,20 +1428,18 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // Issue #109436, we need to add parentheses properly for method calls // for example, `foo.into()` should be `(&foo).into()` - if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet( - self.tcx.sess.source_map().span_look_ahead(span, Some("."), Some(50)), - ) { - if snippet == "." { - err.multipart_suggestion_verbose( - sugg_msg, - vec![ - (span.shrink_to_lo(), format!("({sugg_prefix}")), - (span.shrink_to_hi(), ")".to_string()), - ], - Applicability::MaybeIncorrect, - ); - return true; - } + if let Some(_) = + self.tcx.sess.source_map().span_look_ahead(span, ".", Some(50)) + { + err.multipart_suggestion_verbose( + sugg_msg, + vec![ + (span.shrink_to_lo(), format!("({sugg_prefix}")), + (span.shrink_to_hi(), ")".to_string()), + ], + Applicability::MaybeIncorrect, + ); + return true; } // Issue #104961, we need to add parentheses properly for compound expressions