diff options
| -rw-r--r-- | src/librustc/middle/ty.rs | 7 | ||||
| -rw-r--r-- | src/librustc/middle/typeck/check/mod.rs | 16 | ||||
| -rw-r--r-- | src/test/compile-fail/indexing-requires-a-uint.rs | 25 |
3 files changed, 47 insertions, 1 deletions
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs index 8a616496f06..e8082e149af 100644 --- a/src/librustc/middle/ty.rs +++ b/src/librustc/middle/ty.rs @@ -2602,6 +2602,13 @@ pub fn type_is_integral(ty: t) -> bool { } } +pub fn type_is_uint(ty: t) -> bool { + match get(ty).sty { + ty_infer(IntVar(_)) | ty_uint(ast::TyU) => true, + _ => false + } +} + pub fn type_is_char(ty: t) -> bool { match get(ty).sty { ty_char => true, diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs index 9aa98ee5f8e..4cf3cc51cc1 100644 --- a/src/librustc/middle/typeck/check/mod.rs +++ b/src/librustc/middle/typeck/check/mod.rs @@ -3151,7 +3151,7 @@ fn check_expr_with_unifier(fcx: &FnCtxt, lvalue_pref, |base_t, _| ty::index(base_t)); match field_ty { Some(mt) => { - require_integral(fcx, idx.span, idx_t); + check_expr_has_type(fcx, idx, ty::mk_uint()); fcx.write_ty(id, mt.ty); fcx.write_autoderef_adjustment(base.id, autoderefs); } @@ -3195,6 +3195,15 @@ fn check_expr_with_unifier(fcx: &FnCtxt, unifier(); } +pub fn require_uint(fcx: &FnCtxt, sp: Span, t: ty::t) { + if !type_is_uint(fcx, sp, t) { + fcx.type_error_message(sp, |actual| { + format!("mismatched types: expected `uint` type but found `{}`", + actual) + }, t, None); + } +} + pub fn require_integral(fcx: &FnCtxt, sp: Span, t: ty::t) { if !type_is_integral(fcx, sp, t) { fcx.type_error_message(sp, |actual| { @@ -3854,6 +3863,11 @@ pub fn type_is_integral(fcx: &FnCtxt, sp: Span, typ: ty::t) -> bool { return ty::type_is_integral(typ_s); } +pub fn type_is_uint(fcx: &FnCtxt, sp: Span, typ: ty::t) -> bool { + let typ_s = structurally_resolved_type(fcx, sp, typ); + return ty::type_is_uint(typ_s); +} + pub fn type_is_scalar(fcx: &FnCtxt, sp: Span, typ: ty::t) -> bool { let typ_s = structurally_resolved_type(fcx, sp, typ); return ty::type_is_scalar(typ_s); diff --git a/src/test/compile-fail/indexing-requires-a-uint.rs b/src/test/compile-fail/indexing-requires-a-uint.rs new file mode 100644 index 00000000000..9ac4bd2566e --- /dev/null +++ b/src/test/compile-fail/indexing-requires-a-uint.rs @@ -0,0 +1,25 @@ +// Copyright 2014 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. + +// Make sure that indexing an array is only valid with a `uint`, not any other +// integral type. + +fn main() { + fn bar<T>(_: T) {} + [0][0u8]; //~ ERROR: mismatched types + + [0][0]; // should infer to be a uint + + let i = 0; // i is an IntVar + [0][i]; // i should be locked to uint + bar::<int>(i); // i should not be re-coerced back to an int + //~^ ERROR: mismatched types +} + |