53 lines
2.0 KiB
Rust
53 lines
2.0 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use syntax::ast;
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use super::err::*;
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/// Depending on the target only one variant is ever used in a compilation.
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/// Anything else is an error. This invariant is checked at several locations
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#[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, Hash, Eq, PartialEq)]
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pub enum ConstIsize {
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Is16(i16),
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Is32(i32),
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Is64(i64),
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}
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pub use self::ConstIsize::*;
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impl ConstIsize {
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pub fn as_i64(self, target_int_ty: ast::IntTy) -> i64 {
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match (self, target_int_ty) {
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(Is16(i), ast::IntTy::I16) => i as i64,
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(Is32(i), ast::IntTy::I32) => i as i64,
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(Is64(i), ast::IntTy::I64) => i,
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_ => panic!("unable to convert self ({:?}) to target isize ({:?})",
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self, target_int_ty),
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}
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}
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pub fn new(i: i64, target_int_ty: ast::IntTy) -> Result<Self, ConstMathErr> {
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match target_int_ty {
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ast::IntTy::I16 if i as i16 as i64 == i => Ok(Is16(i as i16)),
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ast::IntTy::I16 => Err(LitOutOfRange(ast::IntTy::Is)),
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ast::IntTy::I32 if i as i32 as i64 == i => Ok(Is32(i as i32)),
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ast::IntTy::I32 => Err(LitOutOfRange(ast::IntTy::Is)),
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ast::IntTy::I64 => Ok(Is64(i)),
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_ => unreachable!(),
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}
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}
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pub fn new_truncating(i: i64, target_int_ty: ast::IntTy) -> Self {
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match target_int_ty {
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ast::IntTy::I16 => Is16(i as i16),
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ast::IntTy::I32 => Is32(i as i32),
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ast::IntTy::I64 => Is64(i),
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_ => unreachable!(),
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}
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}
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}
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