Skip to content

Commit

Permalink
Do not suggest .into() in consts
Browse files Browse the repository at this point in the history
  • Loading branch information
estebank committed Mar 19, 2018
1 parent adf2135 commit 1b8f1fc
Show file tree
Hide file tree
Showing 3 changed files with 50 additions and 1 deletion.
15 changes: 14 additions & 1 deletion src/librustc_typeck/check/demand.rs
Original file line number Diff line number Diff line change
Expand Up @@ -18,8 +18,9 @@ use syntax::ast;
use syntax::util::parser::PREC_POSTFIX;
use syntax_pos::{self, Span};
use rustc::hir;
use rustc::hir::print;
use rustc::hir::def::Def;
use rustc::hir::map::NodeItem;
use rustc::hir::{Item, ItemConst, print};
use rustc::ty::{self, Ty, AssociatedItem};
use errors::{DiagnosticBuilder, CodeMapper};

Expand Down Expand Up @@ -318,6 +319,18 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
checked_ty: Ty<'tcx>,
expected_ty: Ty<'tcx>)
-> bool {
let parent_id = self.tcx.hir.get_parent_node(expr.id);
match self.tcx.hir.find(parent_id) {
Some(parent) => {
// Shouldn't suggest `.into()` on `const`s.
if let NodeItem(Item { node: ItemConst(_, _), .. }) = parent {
// FIXME(estebank): modify once we decide to suggest `as` casts
return false;
}
}
None => {}
};

let will_truncate = "will truncate the source value";
let depending_on_isize = "will truncate or zero-extend depending on the bit width of \
`isize`";
Expand Down
21 changes: 21 additions & 0 deletions src/test/ui/suggestions/const-type-mismatch.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,21 @@
// Copyright 2018 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.

// `const`s shouldn't suggest `.into()`

const TEN: u8 = 10;
const TWELVE: u16 = TEN + 2;
//~^ ERROR mismatched types [E0308]

fn main() {
const TEN: u8 = 10;
const ALSO_TEN: u16 = TEN;
//~^ ERROR mismatched types [E0308]
}
15 changes: 15 additions & 0 deletions src/test/ui/suggestions/const-type-mismatch.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
error[E0308]: mismatched types
--> $DIR/const-type-mismatch.rs:14:21
|
LL | const TWELVE: u16 = TEN + 2;
| ^^^^^^^ expected u16, found u8

error[E0308]: mismatched types
--> $DIR/const-type-mismatch.rs:19:27
|
LL | const ALSO_TEN: u16 = TEN;
| ^^^ expected u16, found u8

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0308`.

0 comments on commit 1b8f1fc

Please sign in to comment.