Auto merge of #37554 - mikhail-m1:dnlle, r=jonathandturner

Improve "Doesn't live long enough" error

case with temporary variable

issue #36279 part of #35233

r? @jonathandturner
This commit is contained in:
bors 2016-11-12 05:20:56 -08:00 committed by GitHub
commit acce384c22
9 changed files with 63 additions and 24 deletions

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@ -1009,11 +1009,11 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
}
err_out_of_scope(super_scope, sub_scope, cause) => {
let (value_kind, value_msg, is_temporary) = match err.cmt.cat {
let (value_kind, value_msg) = match err.cmt.cat {
mc::Categorization::Rvalue(_) =>
("temporary value", "temporary value created here", true),
("temporary value", "temporary value created here"),
_ =>
("borrowed value", "does not live long enough", false)
("borrowed value", "borrow occurs here")
};
let is_closure = match cause {
@ -1026,14 +1026,14 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
Some(primary) => {
db.span = MultiSpan::from_span(s);
db.span_label(primary, &format!("capture occurs here"));
db.span_label(s, &value_msg);
db.span_label(s, &"does not live long enough");
true
}
None => false
}
}
_ => {
db.span_label(error_span, &value_msg);
db.span_label(error_span, &"does not live long enough");
false
}
};
@ -1043,11 +1043,11 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
match (sub_span, super_span) {
(Some(s1), Some(s2)) if s1 == s2 => {
if !is_temporary && !is_closure {
if !is_closure {
db.span = MultiSpan::from_span(s1);
db.span_label(error_span, &format!("borrow occurs here"));
db.span_label(error_span, &value_msg);
let msg = match opt_loan_path(&err.cmt) {
None => "borrowed value".to_string(),
None => value_kind.to_string(),
Some(lp) => {
format!("`{}`", self.loan_path_to_string(&lp))
}
@ -1060,17 +1060,16 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
db.note("values in a scope are dropped in the opposite order \
they are created");
}
(Some(s1), Some(s2)) if !is_temporary && !is_closure => {
(Some(s1), Some(s2)) if !is_closure => {
db.span = MultiSpan::from_span(s2);
db.span_label(error_span, &format!("borrow occurs here"));
db.span_label(error_span, &value_msg);
let msg = match opt_loan_path(&err.cmt) {
None => "borrowed value".to_string(),
None => value_kind.to_string(),
Some(lp) => {
format!("`{}`", self.loan_path_to_string(&lp))
}
};
db.span_label(s2,
&format!("{} dropped here while still borrowed", msg));
db.span_label(s2, &format!("{} dropped here while still borrowed", msg));
db.span_label(s1, &format!("{} needs to live until here", value_kind));
}
_ => {

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@ -1,8 +1,8 @@
error: borrowed value does not live long enough
--> $DIR/borrowck-let-suggestion.rs:12:13
--> $DIR/borrowck-let-suggestion.rs:12:23
|
12 | let x = [1].iter();
| ^^^ - temporary value only lives until here
| --- ^ temporary value dropped here while still borrowed
| |
| temporary value created here
13 | }

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@ -10,10 +10,10 @@ error: `young[..]` does not live long enough
= note: values in a scope are dropped in the opposite order they are created
error: borrowed value does not live long enough
--> $DIR/borrowck-let-suggestion-suffixes.rs:24:14
--> $DIR/borrowck-let-suggestion-suffixes.rs:24:18
|
24 | v3.push(&'x'); // statement 6
| ^^^ - temporary value only lives until here
| --- ^ temporary value dropped here while still borrowed
| |
| temporary value created here
...
@ -23,10 +23,10 @@ error: borrowed value does not live long enough
= note: consider using a `let` binding to increase its lifetime
error: borrowed value does not live long enough
--> $DIR/borrowck-let-suggestion-suffixes.rs:34:18
--> $DIR/borrowck-let-suggestion-suffixes.rs:34:22
|
34 | v4.push(&'y');
| ^^^ - temporary value only lives until here
| --- ^ temporary value dropped here while still borrowed
| |
| temporary value created here
...
@ -36,10 +36,10 @@ error: borrowed value does not live long enough
= note: consider using a `let` binding to increase its lifetime
error: borrowed value does not live long enough
--> $DIR/borrowck-let-suggestion-suffixes.rs:45:14
--> $DIR/borrowck-let-suggestion-suffixes.rs:45:18
|
45 | v5.push(&'z');
| ^^^ - temporary value only lives until here
| --- ^ temporary value dropped here while still borrowed
| |
| temporary value created here
...

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@ -11,7 +11,6 @@
fn main() {
let v = vec![
&3
//~^ ERROR borrowed value does not live long enough
];
for &&x in &v {

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@ -0,0 +1,15 @@
error: borrowed value does not live long enough
--> $DIR/issue-15480.rs:14:6
|
13 | &3
| - temporary value created here
14 | ];
| ^ temporary value dropped here while still borrowed
...
19 | }
| - temporary value needs to live until here
|
= note: consider using a `let` binding to increase its lifetime
error: aborting due to previous error

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@ -17,7 +17,7 @@ impl<'a> Foo for &'a isize { }
fn main() {
let blah;
{
let ss: &isize = &1; //~ ERROR borrowed value does not live long enough
let ss: &isize = &1;
blah = box ss as Box<Foo>;
}
}

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@ -0,0 +1,13 @@
error: borrowed value does not live long enough
--> $DIR/regions-close-over-borrowed-ref-in-obj.rs:22:5
|
20 | let ss: &isize = &1;
| - temporary value created here
21 | blah = box ss as Box<Foo>;
22 | }
| ^ temporary value dropped here while still borrowed
23 | }
| - temporary value needs to live until here
error: aborting due to previous error

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@ -13,7 +13,7 @@
fn main() {
let y;
{
let x: &[isize] = &[1, 2, 3, 4, 5]; //~ ERROR borrowed value does not live long enough
let x: &[isize] = &[1, 2, 3, 4, 5];
y = &x[1..];
}
}

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@ -0,0 +1,13 @@
error: borrowed value does not live long enough
--> $DIR/slice-borrow.rs:18:5
|
16 | let x: &[isize] = &[1, 2, 3, 4, 5];
| --------------- temporary value created here
17 | y = &x[1..];
18 | }
| ^ temporary value dropped here while still borrowed
19 | }
| - temporary value needs to live until here
error: aborting due to previous error