src/librustc_mir/build/cfg.rs

   1 // Copyright 2015 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
  13
  14 //! Routines for manipulating the control-flow graph.
  15
  16 use build::CFG;
  17 use rustc::mir::repr::*;
  18 use syntax::codemap::Span;
  19
  20 impl<'tcx> CFG<'tcx> {
  21     pub fn block_data(&self, blk: BasicBlock) -> &BasicBlockData<'tcx> {
  22         &self.basic_blocks[blk.index()]
  23     }
  24
  25     pub fn block_data_mut(&mut self, blk: BasicBlock) -> &mut BasicBlockData<'tcx> {
  26         &mut self.basic_blocks[blk.index()]
  27     }
  28
  29     pub fn start_new_block(&mut self) -> BasicBlock {
  30         let node_index = self.basic_blocks.len();
  31         self.basic_blocks.push(BasicBlockData::new(None));
  32         BasicBlock::new(node_index)
  33     }
  34
  35     pub fn start_new_cleanup_block(&mut self) -> BasicBlock {
  36         let bb = self.start_new_block();
  37         self.block_data_mut(bb).is_cleanup = true;
  38         bb
  39     }
  40
  41     pub fn push(&mut self, block: BasicBlock, statement: Statement<'tcx>) {
  42         debug!("push({:?}, {:?})", block, statement);
  43         self.block_data_mut(block).statements.push(statement);
  44     }
  45
  46     pub fn push_drop(&mut self, block: BasicBlock, span: Span, lvalue: &Lvalue<'tcx>) {
  47         self.push(block, Statement {
  48             span: span,
  49             kind: StatementKind::Drop(lvalue.clone())
  50         });
  51     }
  52
  53     pub fn push_assign(&mut self,
  54                        block: BasicBlock,
  55                        span: Span,
  56                        lvalue: &Lvalue<'tcx>,
  57                        rvalue: Rvalue<'tcx>) {
  58         self.push(block, Statement {
  59             span: span,
  60             kind: StatementKind::Assign(lvalue.clone(), rvalue)
  61         });
  62     }
  63
  64     pub fn push_assign_constant(&mut self,
  65                                 block: BasicBlock,
  66                                 span: Span,
  67                                 temp: &Lvalue<'tcx>,
  68                                 constant: Constant<'tcx>) {
  69         self.push_assign(block, span, temp, Rvalue::Use(Operand::Constant(constant)));
  70     }
  71
  72     pub fn push_assign_unit(&mut self,
  73                             block: BasicBlock,
  74                             span: Span,
  75                             lvalue: &Lvalue<'tcx>) {
  76         self.push_assign(block, span, lvalue, Rvalue::Aggregate(
  77             AggregateKind::Tuple, vec![]
  78         ));
  79     }
  80
  81     pub fn terminate(&mut self,
  82                      block: BasicBlock,
  83                      terminator: Terminator<'tcx>) {
  84         debug_assert!(self.block_data(block).terminator.is_none(),
  85                       "terminate: block {:?} already has a terminator set", block);
  86         self.block_data_mut(block).terminator = Some(terminator);
  87     }
  88 }