| // Copyright 2015 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. |
| |
| use syntax::ast; |
| use super::err::*; |
| |
| /// Depending on the target only one variant is ever used in a compilation. |
| /// Anything else is an error. This invariant is checked at several locations |
| #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, Hash, Eq, PartialEq)] |
| pub enum ConstIsize { |
| Is16(i16), |
| Is32(i32), |
| Is64(i64), |
| } |
| pub use self::ConstIsize::*; |
| |
| impl ConstIsize { |
| pub fn as_i64(self, target_int_ty: ast::IntTy) -> i64 { |
| match (self, target_int_ty) { |
| (Is16(i), ast::IntTy::I16) => i as i64, |
| (Is32(i), ast::IntTy::I32) => i as i64, |
| (Is64(i), ast::IntTy::I64) => i, |
| _ => panic!("unable to convert self ({:?}) to target isize ({:?})", |
| self, target_int_ty), |
| } |
| } |
| pub fn new(i: i64, target_int_ty: ast::IntTy) -> Result<Self, ConstMathErr> { |
| match target_int_ty { |
| ast::IntTy::I16 if i as i16 as i64 == i => Ok(Is16(i as i16)), |
| ast::IntTy::I16 => Err(LitOutOfRange(ast::IntTy::Is)), |
| ast::IntTy::I32 if i as i32 as i64 == i => Ok(Is32(i as i32)), |
| ast::IntTy::I32 => Err(LitOutOfRange(ast::IntTy::Is)), |
| ast::IntTy::I64 => Ok(Is64(i)), |
| _ => unreachable!(), |
| } |
| } |
| pub fn new_truncating(i: i64, target_int_ty: ast::IntTy) -> Self { |
| match target_int_ty { |
| ast::IntTy::I16 => Is16(i as i16), |
| ast::IntTy::I32 => Is32(i as i32), |
| ast::IntTy::I64 => Is64(i), |
| _ => unreachable!(), |
| } |
| } |
| } |