rust/src/librustc/middle/astconv_util.rs

83 lines
3 KiB
Rust

// Copyright 2012-2014 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.
/*!
* This module contains a simple utility routine
* used by both `typeck` and `const_eval`.
* Almost certainly this could (and should) be refactored out of existence.
*/
use hir;
use hir::def::Def;
use ty::{Ty, TyCtxt};
use syntax_pos::Span;
impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
pub fn prohibit_type_params(self, segments: &[hir::PathSegment]) {
for segment in segments {
for typ in segment.parameters.types() {
struct_span_err!(self.sess, typ.span, E0109,
"type parameters are not allowed on this type")
.span_label(typ.span, &format!("type parameter not allowed"))
.emit();
break;
}
for lifetime in segment.parameters.lifetimes() {
struct_span_err!(self.sess, lifetime.span, E0110,
"lifetime parameters are not allowed on this type")
.span_label(lifetime.span,
&format!("lifetime parameter not allowed on this type"))
.emit();
break;
}
for binding in segment.parameters.bindings() {
self.prohibit_projection(binding.span);
break;
}
}
}
pub fn prohibit_projection(self, span: Span)
{
let mut err = struct_span_err!(self.sess, span, E0229,
"associated type bindings are not allowed here");
err.span_label(span, &format!("associate type not allowed here")).emit();
}
pub fn prim_ty_to_ty(self,
segments: &[hir::PathSegment],
nty: hir::PrimTy)
-> Ty<'tcx> {
self.prohibit_type_params(segments);
match nty {
hir::TyBool => self.types.bool,
hir::TyChar => self.types.char,
hir::TyInt(it) => self.mk_mach_int(it),
hir::TyUint(uit) => self.mk_mach_uint(uit),
hir::TyFloat(ft) => self.mk_mach_float(ft),
hir::TyStr => self.mk_str()
}
}
/// If a type in the AST is a primitive type, return the ty::Ty corresponding
/// to it.
pub fn ast_ty_to_prim_ty(self, ast_ty: &hir::Ty) -> Option<Ty<'tcx>> {
if let hir::TyPath(hir::QPath::Resolved(None, ref path)) = ast_ty.node {
if let Def::PrimTy(nty) = path.def {
Some(self.prim_ty_to_ty(&path.segments, nty))
} else {
None
}
} else {
None
}
}
}