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auto merge of #14801 : pcwalton/rust/name-shadowing-in-one-pattern, r=alexcrichton

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bindings and function arguments.

Issue #14581.

To fix code that this breaks, give the pattern identifiers different names.

[breaking-change]

r? @brson
This commit is contained in:
bors 2014-06-12 12:32:13 +00:00
commit 87bf47a0f7
2 changed files with 46 additions and 42 deletions
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70
src/librustc/middle/resolve.rs
View file

@ -3812,9 +3812,10 @@ impl<'a> Resolver<'a> {
}
Some(declaration) => {
for argument in declaration.inputs.iter() {
let mut bindings_list = HashMap::new();
this.resolve_pattern(&*argument.pat,
ArgumentIrrefutableMode,
None);
&mut bindings_list);
this.resolve_type(&*argument.ty);
@ -4045,7 +4046,10 @@ impl<'a> Resolver<'a> {
}
// Resolve the pattern.
self.resolve_pattern(&*local.pat, LocalIrrefutableMode, None);
let mut bindings_list = HashMap::new();
self.resolve_pattern(&*local.pat,
LocalIrrefutableMode,
&mut bindings_list);
}
// build a map from pattern identifiers to binding-info's.
@ -4114,9 +4118,7 @@ impl<'a> Resolver<'a> {
let mut bindings_list = HashMap::new();
for pattern in arm.pats.iter() {
self.resolve_pattern(&**pattern,
RefutableMode,
Some(&mut bindings_list));
self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
}
// This has to happen *after* we determine which
@ -4262,7 +4264,7 @@ impl<'a> Resolver<'a> {
mode: PatternBindingMode,
// Maps idents to the node ID for the (outermost)
// pattern that binds them
mut bindings_list: Option<&mut HashMap<Name,NodeId>>) {
bindings_list: &mut HashMap<Name,NodeId>) {
let pat_id = pattern.id;
walk_pat(pattern, |pattern| {
match pattern.node {
@ -4351,43 +4353,27 @@ impl<'a> Resolver<'a> {
// because that breaks the assumptions later
// passes make about or-patterns.)
match bindings_list {
Some(ref mut bindings_list)
if !bindings_list.contains_key(&renamed) => {
let this = &mut *self;
let value_ribs = this.value_ribs.borrow();
let length = value_ribs.len();
let last_rib = value_ribs.get(
length - 1);
last_rib.bindings.borrow_mut()
.insert(renamed, DlDef(def));
bindings_list.insert(renamed, pat_id);
}
Some(ref mut b) => {
if b.find(&renamed) == Some(&pat_id) {
// Then this is a duplicate variable
// in the same disjunct, which is an
// error
self.resolve_error(pattern.span,
format!("identifier `{}` is bound \
more than once in the same \
pattern",
path_to_str(path)).as_slice());
}
// Not bound in the same pattern: do nothing
}
None => {
let this = &mut *self;
{
let value_ribs = this.value_ribs.borrow();
let length = value_ribs.len();
let last_rib = value_ribs.get(
length - 1);
last_rib.bindings.borrow_mut()
.insert(renamed, DlDef(def));
}
}
if !bindings_list.contains_key(&renamed) {
let this = &mut *self;
let value_ribs = this.value_ribs.borrow();
let length = value_ribs.len();
let last_rib = value_ribs.get(
length - 1);
last_rib.bindings.borrow_mut()
.insert(renamed, DlDef(def));
bindings_list.insert(renamed, pat_id);
} else if bindings_list.find(&renamed) ==
Some(&pat_id) {
// Then this is a duplicate variable in the
// same disjunction, which is an error.
self.resolve_error(pattern.span,
format!("identifier `{}` is bound \
more than once in the same \
pattern",
path_to_str(path)).as_slice());
}
// Else, not bound in the same pattern: do
// nothing.
}
}

18
src/test/compile-fail/shadowing-in-the-same-pattern.rs Normal file
View file

@ -0,0 +1,18 @@
// Copyright 2013 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.
// Test for issue #14581.
fn f((a, a): (int, int)) {} //~ ERROR identifier `a` is bound more than once
fn main() {
let (a, a) = (1, 1); //~ ERROR identifier `a` is bound more than once
}