1 //! Routines for manipulating the control-flow graph.
4 use rustc_middle::mir::*;
5 use rustc_middle::ty::TyCtxt;
8 pub(crate) fn block_data(&self, blk: BasicBlock) -> &BasicBlockData<'tcx> {
9 &self.basic_blocks[blk]
12 pub(crate) fn block_data_mut(&mut self, blk: BasicBlock) -> &mut BasicBlockData<'tcx> {
13 &mut self.basic_blocks[blk]
16 // llvm.org/PR32488 makes this function use an excess of stack space. Mark
17 // it as #[inline(never)] to keep rustc's stack use in check.
19 pub(crate) fn start_new_block(&mut self) -> BasicBlock {
20 self.basic_blocks.push(BasicBlockData::new(None))
23 pub(crate) fn start_new_cleanup_block(&mut self) -> BasicBlock {
24 let bb = self.start_new_block();
25 self.block_data_mut(bb).is_cleanup = true;
29 pub(crate) fn push(&mut self, block: BasicBlock, statement: Statement<'tcx>) {
30 debug!("push({:?}, {:?})", block, statement);
31 self.block_data_mut(block).statements.push(statement);
34 pub(crate) fn push_assign(
37 source_info: SourceInfo,
43 Statement { source_info, kind: StatementKind::Assign(Box::new((place, rvalue))) },
47 pub(crate) fn push_assign_constant(
50 source_info: SourceInfo,
52 constant: Constant<'tcx>,
58 Rvalue::Use(Operand::Constant(Box::new(constant))),
62 pub(crate) fn push_assign_unit(
65 source_info: SourceInfo,
73 Rvalue::Use(Operand::Constant(Box::new(Constant {
74 span: source_info.span,
76 literal: ConstantKind::zero_sized(tcx.types.unit),
81 pub(crate) fn push_fake_read(
84 source_info: SourceInfo,
88 let kind = StatementKind::FakeRead(Box::new((cause, place)));
89 let stmt = Statement { source_info, kind };
90 self.push(block, stmt);
93 pub(crate) fn terminate(
96 source_info: SourceInfo,
97 kind: TerminatorKind<'tcx>,
99 debug!("terminating block {:?} <- {:?}", block, kind);
101 self.block_data(block).terminator.is_none(),
102 "terminate: block {:?}={:?} already has a terminator set",
104 self.block_data(block)
106 self.block_data_mut(block).terminator = Some(Terminator { source_info, kind });
109 /// In the `origin` block, push a `goto -> target` terminator.
110 pub(crate) fn goto(&mut self, origin: BasicBlock, source_info: SourceInfo, target: BasicBlock) {
111 self.terminate(origin, source_info, TerminatorKind::Goto { target })