user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Auto merge of #48605 - KiChjang:unused-mut-warning, r=nikomatsakis

Browse source 
Allow MIR borrowck to catch unused mutable locals

Fixes #47279.

r? @nikomatsakis
This commit is contained in:
bors 2018-04-29 16:25:04 +00:00
commit 79252ff4e2
8 changed files with 414 additions and 119 deletions
Download patch file Download diff file Expand all files Collapse all files

61
src/test/compile-fail/lint-unused-mut-variables.rs
View file

@ -8,6 +8,9 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// revisions: lexical nll
#![cfg_attr(nll, feature(nll))]
// Exercise the unused_mut attribute in some positive and negative cases
#![allow(unused_assignments)]
@ -18,15 +21,22 @@
fn main() {
// negative cases
let mut a = 3; //~ ERROR: variable does not need to be mutable
let mut a = 2; //~ ERROR: variable does not need to be mutable
let mut b = 3; //~ ERROR: variable does not need to be mutable
let mut a = vec![3]; //~ ERROR: variable does not need to be mutable
let (mut a, b) = (1, 2); //~ ERROR: variable does not need to be mutable
let mut a; //~ ERROR: variable does not need to be mutable
let mut a = 3; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let mut a = 2; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let mut b = 3; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let mut a = vec![3]; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let (mut a, b) = (1, 2); //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let mut a; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
a = 3;
let mut b; //~ ERROR: variable does not need to be mutable
let mut b; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
if true {
b = 3;
} else {
@ -34,37 +44,45 @@ fn main() {
}
match 30 {
mut x => {} //~ ERROR: variable does not need to be mutable
mut x => {} //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
}
match (30, 2) {
(mut x, 1) | //~ ERROR: variable does not need to be mutable
(mut x, 1) | //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
(mut x, 2) |
(mut x, 3) => {
}
_ => {}
}
let x = |mut y: isize| 10; //~ ERROR: variable does not need to be mutable
fn what(mut foo: isize) {} //~ ERROR: variable does not need to be mutable
let x = |mut y: isize| 10; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
fn what(mut foo: isize) {} //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let mut a = &mut 5; //~ ERROR: variable does not need to be mutable
let mut a = &mut 5; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
*a = 4;
let mut a = 5;
let mut b = (&mut a,);
*b.0 = 4; //~^ ERROR: variable does not need to be mutable
let mut b = (&mut a,); //[lexical]~ ERROR: variable does not need to be mutable
*b.0 = 4; //[nll]~^ ERROR: variable does not need to be mutable
let mut x = &mut 1; //~ ERROR: variable does not need to be mutable
let mut x = &mut 1; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
let mut f = || {
*x += 1;
};
f();
fn mut_ref_arg(mut arg : &mut [u8]) -> &mut [u8] {
&mut arg[..] //~^ ERROR: variable does not need to be mutable
&mut arg[..] //[lexical]~^ ERROR: variable does not need to be mutable
//[nll]~^^ ERROR: variable does not need to be mutable
}
let mut v : &mut Vec<()> = &mut vec![]; //~ ERROR: variable does not need to be mutable
let mut v : &mut Vec<()> = &mut vec![]; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
v.push(());
// positive cases
@ -76,6 +94,12 @@ fn main() {
callback(|| {
a.push(3);
});
let mut a = Vec::new();
callback(|| {
callback(|| {
a.push(3);
});
});
let (mut a, b) = (1, 2);
a = 34;
@ -116,5 +140,6 @@ fn foo(mut a: isize) {
fn bar() {
#[allow(unused_mut)]
let mut a = 3;
let mut b = vec![2]; //~ ERROR: variable does not need to be mutable
let mut b = vec![2]; //[lexical]~ ERROR: variable does not need to be mutable
//[nll]~^ ERROR: variable does not need to be mutable
}

56
src/test/run-pass/borrowck/borrowck-unused-mut-locals.rs Normal file
View file

@ -0,0 +1,56 @@
// Copyright 2015 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(nll)]
#![deny(unused_mut)]
#[derive(Debug)]
struct A {}
fn init_a() -> A {
A {}
}
#[derive(Debug)]
struct B<'a> {
ed: &'a mut A,
}
fn init_b<'a>(ed: &'a mut A) -> B<'a> {
B { ed }
}
#[derive(Debug)]
struct C<'a> {
pd: &'a mut B<'a>,
}
fn init_c<'a>(pd: &'a mut B<'a>) -> C<'a> {
C { pd }
}
#[derive(Debug)]
struct D<'a> {
sd: &'a mut C<'a>,
}
fn init_d<'a>(sd: &'a mut C<'a>) -> D<'a> {
D { sd }
}
fn main() {
let mut a = init_a();
let mut b = init_b(&mut a);
let mut c = init_c(&mut b);
let d = init_d(&mut c);
println!("{:?}", d)
}