diff options
| -rw-r--r-- | src/librustc_typeck/check/demand.rs | 15 | ||||
| -rw-r--r-- | src/test/ui/suggestions/const-type-mismatch.rs | 21 | ||||
| -rw-r--r-- | src/test/ui/suggestions/const-type-mismatch.stderr | 15 |
3 files changed, 50 insertions, 1 deletions
diff --git a/src/librustc_typeck/check/demand.rs b/src/librustc_typeck/check/demand.rs index 634a7ee5699..701b896b905 100644 --- a/src/librustc_typeck/check/demand.rs +++ b/src/librustc_typeck/check/demand.rs @@ -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}; @@ -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`"; diff --git a/src/test/ui/suggestions/const-type-mismatch.rs b/src/test/ui/suggestions/const-type-mismatch.rs new file mode 100644 index 00000000000..ddad4e79cfd --- /dev/null +++ b/src/test/ui/suggestions/const-type-mismatch.rs @@ -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] +} diff --git a/src/test/ui/suggestions/const-type-mismatch.stderr b/src/test/ui/suggestions/const-type-mismatch.stderr new file mode 100644 index 00000000000..965995f82c5 --- /dev/null +++ b/src/test/ui/suggestions/const-type-mismatch.stderr @@ -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`. |