From 2461b7a264676fbe24800beb0bcb39ab9e853562 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Thu, 23 Nov 2017 09:58:51 -0800 Subject: [PATCH] Use `get_parent_node` instead of using spans --- src/librustc_typeck/check/_match.rs | 53 ++++++++++--------- src/libsyntax_pos/lib.rs | 12 ----- .../suggestion.stderr | 2 +- .../dont-suggest-dereference-on-arg.stderr | 4 +- 4 files changed, 30 insertions(+), 41 deletions(-) diff --git a/src/librustc_typeck/check/_match.rs b/src/librustc_typeck/check/_match.rs index fbfc97d33c5..f03f782ebb4 100644 --- a/src/librustc_typeck/check/_match.rs +++ b/src/librustc_typeck/check/_match.rs @@ -23,9 +23,7 @@ use std::cmp; use syntax::ast; use syntax::codemap::Spanned; -use syntax::errors::DiagnosticBuilder; use syntax::feature_gate; -use syntax::parse::ParseSess; use syntax::ptr::P; use syntax_pos::Span; @@ -122,32 +120,35 @@ pub fn check_pat_walk( .pat_adjustments_mut() .insert(pat.hir_id, pat_adjustments); } else { - fn feature_err<'a>(sp: Span, sess: &'a ParseSess) -> DiagnosticBuilder<'a> { - feature_gate::feature_err( - sess, - "match_default_bindings", - sp, - feature_gate::GateIssue::Language, - "non-reference pattern used to match a reference", - ) - } - if let Ok(snippet) = tcx.sess.codemap().span_to_snippet(pat.span) { - // The following is a bit of a hack. We probably should check the AST for - // this instead, but this should be good enough for the expected cases. - let prev_span = pat.span.prev_point(); - let (sp, sugg) = match tcx.sess.codemap().span_to_snippet(prev_span) { - // Make the suggestion more obvious when having `&(_, _)` - Ok(ref prev) if &*prev == "&" => { - (prev_span.to(pat.span), format!("&&{}", &snippet)), + let mut ref_sp = pat.span; + let mut id = pat.id; + loop { // make span include all enclosing `&` to avoid confusing diag output + id = tcx.hir.get_parent_node(id); + let node = tcx.hir.find(id); + if let Some(hir::map::NodePat(pat)) = node { + if let hir::PatKind::Ref(..) = pat.node { + ref_sp = pat.span; + } else { + break; } - _ => (pat.span, format!("&{}", &snippet)), - }; - let mut err = feature_err(sp, &tcx.sess.parse_sess); - err.span_suggestion(sp, "consider using a reference", sugg); - err.emit(); - } else { - feature_err(pat.span, &tcx.sess.parse_sess).emit(); + } else { + break; + } } + let sp = ref_sp.to(pat.span); + let mut err = feature_gate::feature_err( + &tcx.sess.parse_sess, + "match_default_bindings", + sp, + feature_gate::GateIssue::Language, + "non-reference pattern used to match a reference", + ); + if let Ok(snippet) = tcx.sess.codemap().span_to_snippet(sp) { + err.span_suggestion(sp, + "consider using a reference", + format!("&{}", &snippet)); + } + err.emit(); } } } diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs index 40a7917613f..47755dc1d54 100644 --- a/src/libsyntax_pos/lib.rs +++ b/src/libsyntax_pos/lib.rs @@ -159,18 +159,6 @@ pub fn next_point(self) -> Span { Span::new(BytePos(lo), BytePos(lo), span.ctxt) } - /// Returns a new span representing the previous character after the start-point of this span - pub fn prev_point(self) -> Span { - let span = self.data(); - let span_lo = span.lo.0; - let lo = if span_lo == 0 { - 0 - } else { - span_lo - 1 - }; - Span::new(BytePos(lo), BytePos(span_lo), span.ctxt) - } - /// Returns `self` if `self` is not the dummy span, and `other` otherwise. pub fn substitute_dummy(self, other: Span) -> Span { if self.source_equal(&DUMMY_SP) { other } else { self } diff --git a/src/test/ui/rfc-2005-default-binding-mode/suggestion.stderr b/src/test/ui/rfc-2005-default-binding-mode/suggestion.stderr index b10980d6bd6..ebf9e498ffd 100644 --- a/src/test/ui/rfc-2005-default-binding-mode/suggestion.stderr +++ b/src/test/ui/rfc-2005-default-binding-mode/suggestion.stderr @@ -2,7 +2,7 @@ error: non-reference pattern used to match a reference (see issue #42640) --> $DIR/suggestion.rs:12:12 | 12 | if let Some(y) = &Some(22) { //~ ERROR non-reference pattern - | ^^^^^^^ help: consider using: `&Some(y)` + | ^^^^^^^ help: consider using a reference: `&Some(y)` | = help: add #![feature(match_default_bindings)] to the crate attributes to enable diff --git a/src/test/ui/suggestions/dont-suggest-dereference-on-arg.stderr b/src/test/ui/suggestions/dont-suggest-dereference-on-arg.stderr index fc1eb335d05..56303146d5d 100644 --- a/src/test/ui/suggestions/dont-suggest-dereference-on-arg.stderr +++ b/src/test/ui/suggestions/dont-suggest-dereference-on-arg.stderr @@ -1,8 +1,8 @@ error: non-reference pattern used to match a reference (see issue #42640) - --> dont-suggest-dereference-on-arg.rs:16:19 + --> $DIR/dont-suggest-dereference-on-arg.rs:16:19 | 16 | .filter(|&(ref a, _)| foo(a)) - | ^^^^^^^^^^^ help: consider using: `&&(ref k, _)` + | ^^^^^^^^^^^ help: consider using a reference: `&&(ref k, _)` | = help: add #![feature(match_default_bindings)] to the crate attributes to enable