src/librustc/middle/astconv_util.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 /*!
  12  * This module contains a simple utility routine
  13  * used by both `typeck` and `const_eval`.
  14  * Almost certainly this could (and should) be refactored out of existence.
  15  */
  16
  17 use middle::def;
  18 use middle::ty::{self, Ty};
  19 use syntax::ast;
  20
  21 pub const NO_REGIONS: usize = 1;
  22 pub const NO_TPS: usize = 2;
  23
  24 pub fn check_path_args(tcx: &ty::ctxt, segments: &[ast::PathSegment], flags: usize) {
  25     for segment in segments {
  26         if (flags & NO_TPS) != 0 {
  27             for typ in segment.parameters.types() {
  28                 span_err!(tcx.sess, typ.span, E0109,
  29                           "type parameters are not allowed on this type");
  30                 break;
  31             }
  32         }
  33
  34         if (flags & NO_REGIONS) != 0 {
  35             for lifetime in segment.parameters.lifetimes() {
  36                 span_err!(tcx.sess, lifetime.span, E0110,
  37                           "lifetime parameters are not allowed on this type");
  38                 break;
  39             }
  40         }
  41     }
  42 }
  43
  44 pub fn prim_ty_to_ty<'tcx>(tcx: &ty::ctxt<'tcx>,
  45                            segments: &[ast::PathSegment],
  46                            nty: ast::PrimTy)
  47                            -> Ty<'tcx> {
  48     check_path_args(tcx, segments, NO_TPS | NO_REGIONS);
  49     match nty {
  50         ast::TyBool => tcx.types.bool,
  51         ast::TyChar => tcx.types.char,
  52         ast::TyInt(it) => tcx.mk_mach_int(it),
  53         ast::TyUint(uit) => tcx.mk_mach_uint(uit),
  54         ast::TyFloat(ft) => tcx.mk_mach_float(ft),
  55         ast::TyStr => tcx.mk_str()
  56     }
  57 }
  58
  59 pub fn ast_ty_to_prim_ty<'tcx>(tcx: &ty::ctxt<'tcx>, ast_ty: &ast::Ty)
  60                                -> Option<Ty<'tcx>> {
  61     if let ast::TyPath(None, ref path) = ast_ty.node {
  62         let def = match tcx.def_map.borrow().get(&ast_ty.id) {
  63             None => {
  64                 tcx.sess.span_bug(ast_ty.span,
  65                                   &format!("unbound path {:?}", path))
  66             }
  67             Some(d) => d.full_def()
  68         };
  69         if let def::DefPrimTy(nty) = def {
  70             Some(prim_ty_to_ty(tcx, &path.segments, nty))
  71         } else {
  72             None
  73         }
  74     } else {
  75         None
  76     }
  77 }