src/librustc_trans/mir/statement.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 use rustc::mir::repr as mir;
  12 use common::BlockAndBuilder;
  13
  14 use super::MirContext;
  15 use super::TempRef;
  16
  17 impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
  18     pub fn trans_statement(&mut self,
  19                            bcx: BlockAndBuilder<'bcx, 'tcx>,
  20                            statement: &mir::Statement<'tcx>)
  21                            -> BlockAndBuilder<'bcx, 'tcx> {
  22         debug!("trans_statement(statement={:?})", statement);
  23
  24         match statement.kind {
  25             mir::StatementKind::Assign(ref lvalue, ref rvalue) => {
  26                 match *lvalue {
  27                     mir::Lvalue::Temp(index) => {
  28                         let index = index as usize;
  29                         match self.temps[index as usize] {
  30                             TempRef::Lvalue(tr_dest) => {
  31                                 self.trans_rvalue(bcx, tr_dest, rvalue)
  32                             }
  33                             TempRef::Operand(None) => {
  34                                 let (bcx, operand) = self.trans_rvalue_operand(bcx, rvalue);
  35                                 self.temps[index] = TempRef::Operand(Some(operand));
  36                                 bcx
  37                             }
  38                             TempRef::Operand(Some(_)) => {
  39                                 span_bug!(statement.span,
  40                                           "operand {:?} already assigned",
  41                                           rvalue);
  42                             }
  43                         }
  44                     }
  45                     _ => {
  46                         let tr_dest = self.trans_lvalue(&bcx, lvalue);
  47                         self.trans_rvalue(bcx, tr_dest, rvalue)
  48                     }
  49                 }
  50             }
  51         }
  52     }
  53 }