Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

librustc: Forbid identifiers that shadow in the same pattern in let #14801

Merged
merged 1 commit into from
Jun 12, 2014
Merged

librustc: Forbid identifiers that shadow in the same pattern in let #14801

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
70 changes: 28 additions & 42 deletions src/librustc/middle/resolve.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down Expand Up @@ -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.
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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 {
Expand Down Expand Up @@ -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.
}
}

Expand Down
18 changes: 18 additions & 0 deletions src/test/compile-fail/shadowing-in-the-same-pattern.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -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
}