diff options
| -rw-r--r-- | src/librustc_const_eval/_match.rs | 14 | ||||
| -rw-r--r-- | src/test/ui/check_match/issue-43253.rs | 51 | ||||
| -rw-r--r-- | src/test/ui/check_match/issue-43253.stderr | 20 |
3 files changed, 78 insertions, 7 deletions
diff --git a/src/librustc_const_eval/_match.rs b/src/librustc_const_eval/_match.rs index 98d90188312..bae44c0047e 100644 --- a/src/librustc_const_eval/_match.rs +++ b/src/librustc_const_eval/_match.rs @@ -835,7 +835,7 @@ fn slice_pat_covered_by_constructor(_tcx: TyCtxt, _span: Span, Ok(true) } -fn range_covered_by_constructor(tcx: TyCtxt, span: Span, +fn constructor_covered_by_range(tcx: TyCtxt, span: Span, ctor: &Constructor, from: &ConstVal, to: &ConstVal, end: RangeEnd) @@ -845,14 +845,14 @@ fn range_covered_by_constructor(tcx: TyCtxt, span: Span, match *ctor { ConstantValue(ref value) => { let to = cmp_to(value)?; - let end = (to != Ordering::Greater) || - (end == RangeEnd::Excluded && to == Ordering::Equal); + let end = (to == Ordering::Less) || + (end == RangeEnd::Included && to == Ordering::Equal); Ok(cmp_from(value)? && end) }, ConstantRange(ref from, ref to, RangeEnd::Included) => { let to = cmp_to(to)?; - let end = (to != Ordering::Greater) || - (end == RangeEnd::Excluded && to == Ordering::Equal); + let end = (to == Ordering::Less) || + (end == RangeEnd::Included && to == Ordering::Equal); Ok(cmp_from(from)? && end) }, ConstantRange(ref from, ref to, RangeEnd::Excluded) => { @@ -933,7 +933,7 @@ fn specialize<'p, 'a: 'p, 'tcx: 'a>( "unexpected const-val {:?} with ctor {:?}", value, constructor) }, _ => { - match range_covered_by_constructor( + match constructor_covered_by_range( cx.tcx, pat.span, constructor, value, value, RangeEnd::Included ) { Ok(true) => Some(vec![]), @@ -945,7 +945,7 @@ fn specialize<'p, 'a: 'p, 'tcx: 'a>( } PatternKind::Range { ref lo, ref hi, ref end } => { - match range_covered_by_constructor( + match constructor_covered_by_range( cx.tcx, pat.span, constructor, lo, hi, end.clone() ) { Ok(true) => Some(vec![]), diff --git a/src/test/ui/check_match/issue-43253.rs b/src/test/ui/check_match/issue-43253.rs new file mode 100644 index 00000000000..c77fa74f6e0 --- /dev/null +++ b/src/test/ui/check_match/issue-43253.rs @@ -0,0 +1,51 @@ +// Copyright 2017 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. + +#![feature(exclusive_range_pattern)] + +fn main() { + // These cases should generate no warning. + match 10 { + 1..10 => {}, + 10 => {}, + _ => {}, + } + + match 10 { + 1..10 => {}, + 9...10 => {}, + _ => {}, + } + + match 10 { + 1..10 => {}, + 10...10 => {}, + _ => {}, + } + + // These cases should generate an "unreachable pattern" warning. + match 10 { + 1..10 => {}, + 9 => {}, + _ => {}, + } + + match 10 { + 1..10 => {}, + 8...9 => {}, + _ => {}, + } + + match 10 { + 1..10 => {}, + 9...9 => {}, + _ => {}, + } +} \ No newline at end of file diff --git a/src/test/ui/check_match/issue-43253.stderr b/src/test/ui/check_match/issue-43253.stderr new file mode 100644 index 00000000000..0d4a2ecf512 --- /dev/null +++ b/src/test/ui/check_match/issue-43253.stderr @@ -0,0 +1,20 @@ +warning: unreachable pattern + --> $DIR/issue-43253.rs:36:9 + | +36 | 9 => {}, + | ^ + | + = note: #[warn(unreachable_patterns)] on by default + +warning: unreachable pattern + --> $DIR/issue-43253.rs:42:9 + | +42 | 8...9 => {}, + | ^^^^^ + +warning: unreachable pattern + --> $DIR/issue-43253.rs:48:9 + | +48 | 9...9 => {}, + | ^^^^^ + |