Auto merge of #44516 - gaurikholkar:fns, r=arielb1

Extend E0623 for fn items

This fixes #44516
The below example now gives
```
error[E0623]: lifetime mismatch
 --> gg.rs:3:10
  |
2 | fn foo(x:fn(&u8, &u8), y: Vec<&u8>, z: &u8) {
  |                               ---      --- these two types are declared with different lifetimes...
3 |   y.push(z);
  |          ^ ...but data from `z` flows into `y` here

error: aborting due to previous error
```

r? @nikomatsakis
cc @arielb1
This commit is contained in:
bors 2017-09-13 21:20:19 +00:00
commit 94211416bc
11 changed files with 151 additions and 2 deletions

8
fn.rs Normal file
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@ -0,0 +1,8 @@
fn foo(x: fn(&u8, &u8), y: Vec<&u8>, z: &u8) {
// Debruijn 1 1 1 1
// Anon-Index 0 1 0 1
// ------
// debruijn indices are shifted by 1 in here
y.push(z); // index will be zero or one
}

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@ -173,6 +173,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
hir_map: &self.tcx.hir,
bound_region: *br,
found_type: None,
depth: 1,
};
nested_visitor.visit_ty(arg);
nested_visitor.found_type
@ -195,6 +196,7 @@ struct FindNestedTypeVisitor<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
// The type where the anonymous lifetime appears
// for e.g. Vec<`&u8`> and <`&u8`>
found_type: Option<&'gcx hir::Ty>,
depth: u32,
}
impl<'a, 'gcx, 'tcx> Visitor<'gcx> for FindNestedTypeVisitor<'a, 'gcx, 'tcx> {
@ -204,6 +206,21 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for FindNestedTypeVisitor<'a, 'gcx, 'tcx> {
fn visit_ty(&mut self, arg: &'gcx hir::Ty) {
match arg.node {
hir::TyBareFn(_) => {
self.depth += 1;
intravisit::walk_ty(self, arg);
self.depth -= 1;
return;
}
hir::TyTraitObject(ref bounds, _) => {
for bound in bounds {
self.depth += 1;
self.visit_poly_trait_ref(bound, hir::TraitBoundModifier::None);
self.depth -= 1;
}
}
hir::TyRptr(ref lifetime, _) => {
// the lifetime of the TyRptr
let hir_id = self.infcx.tcx.hir.node_to_hir_id(lifetime.id);
@ -217,7 +234,7 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for FindNestedTypeVisitor<'a, 'gcx, 'tcx> {
debruijn_index.depth,
anon_index,
br_index);
if debruijn_index.depth == 1 && anon_index == br_index {
if debruijn_index.depth == self.depth && anon_index == br_index {
self.found_type = Some(arg);
return; // we can stop visiting now
}
@ -246,7 +263,7 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for FindNestedTypeVisitor<'a, 'gcx, 'tcx> {
debug!("self.infcx.tcx.hir.local_def_id(id)={:?}",
self.infcx.tcx.hir.local_def_id(id));
debug!("def_id={:?}", def_id);
if debruijn_index.depth == 1 &&
if debruijn_index.depth == self.depth &&
self.infcx.tcx.hir.local_def_id(id) == def_id {
self.found_type = Some(arg);
return; // we can stop visiting now

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@ -0,0 +1,18 @@
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-4.rs:12:13
|
11 | fn foo(z: &mut Vec<(&u8,&u8)>, (x, y): (&u8, &u8)) {
| --- --- these references are declared with different lifetimes...
12 | z.push((x,y));
| ^ ...but data flows into `z` here
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-4.rs:12:15
|
11 | fn foo(z: &mut Vec<(&u8,&u8)>, (x, y): (&u8, &u8)) {
| --- --- these references are declared with different lifetimes...
12 | z.push((x,y));
| ^ ...but data flows into `z` here
error: aborting due to 2 previous errors

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@ -0,0 +1,19 @@
// 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.
struct Ref<'a, 'b> {
a: &'a u32,
b: &'b u32,
}
fn foo(mut x: Ref) {
x.a = x.b;
}
fn main() {}

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@ -0,0 +1,12 @@
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-both-are-structs-4.rs:16:11
|
15 | fn foo(mut x: Ref) {
| ---
| |
| this type was declared with multiple lifetimes...
16 | x.a = x.b;
| ^^^ ...but data with one lifetime flows into the other here
error: aborting due to previous error

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@ -0,0 +1,17 @@
// 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.
struct Ref<'a, 'b> { a: &'a u32, b: &'b u32 }
fn foo(mut y: Ref, x: &u32) {
y.b = x;
}
fn main() { }

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@ -0,0 +1,10 @@
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-one-is-struct-4.rs:14:11
|
13 | fn foo(mut y: Ref, x: &u32) {
| --- ---- these two types are declared with different lifetimes...
14 | y.b = x;
| ^ ...but data from `x` flows into `y` here
error: aborting due to previous error

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@ -0,0 +1,14 @@
// 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.
fn foo(x:fn(&u8, &u8), y: Vec<&u8>, z: &u8) {
y.push(z);
}
fn main() { }

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@ -0,0 +1,10 @@
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-using-fn-items.rs:11:10
|
10 | fn foo(x:fn(&u8, &u8), y: Vec<&u8>, z: &u8) {
| --- --- these two types are declared with different lifetimes...
11 | y.push(z);
| ^ ...but data from `z` flows into `y` here
error: aborting due to previous error

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@ -0,0 +1,14 @@
// 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.
fn foo(x:Box<Fn(&u8, &u8)> , y: Vec<&u8>, z: &u8) {
y.push(z);
}
fn main() { }

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@ -0,0 +1,10 @@
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-using-trait-objects.rs:11:10
|
10 | fn foo(x:Box<Fn(&u8, &u8)> , y: Vec<&u8>, z: &u8) {
| --- --- these two types are declared with different lifetimes...
11 | y.push(z);
| ^ ...but data from `z` flows into `y` here
error: aborting due to previous error