refactor AbstractConstBuilder

This commit is contained in:
Bastian Kauschke 2020-09-11 09:00:21 +02:00
parent c3a772f55f
commit f24d532749

View File

@ -187,11 +187,7 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> {
}
}
fn build(mut self) -> Option<&'tcx [Node<'tcx>]> {
let mut block = &self.body.basic_blocks()[mir::START_BLOCK];
loop {
debug!("AbstractConstBuilder: block={:?}", block);
for stmt in block.statements.iter() {
fn build_statement(&mut self, stmt: &mir::Statement<'tcx>) -> Option<()> {
debug!("AbstractConstBuilder: stmt={:?}", stmt);
match stmt.kind {
StatementKind::Assign(box (ref place, ref rvalue)) => {
@ -208,9 +204,7 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> {
bug!("unexpected unchecked checkable binary operation");
}
}
Rvalue::CheckedBinaryOp(op, ref lhs, ref rhs)
if Self::check_binop(op) =>
{
Rvalue::CheckedBinaryOp(op, ref lhs, ref rhs) if Self::check_binop(op) => {
let lhs = self.operand_to_node(lhs)?;
let rhs = self.operand_to_node(rhs)?;
self.locals[local] = self.add_node(Node::Binop(op, lhs, rhs));
@ -221,17 +215,18 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> {
}
_ => return None,
}
Some(())
}
debug!("AbstractConstBuilder: terminator={:?}", block.terminator());
match block.terminator().kind {
TerminatorKind::Goto { target } => {
block = &self.body.basic_blocks()[target];
}
TerminatorKind::Return => {
warn!(?self.nodes);
return { Some(self.tcx.arena.alloc_from_iter(self.nodes)) };
}
fn build_terminator(
&mut self,
terminator: &mir::Terminator<'tcx>,
) -> Option<Option<mir::BasicBlock>> {
debug!("AbstractConstBuilder: terminator={:?}", terminator);
match terminator.kind {
TerminatorKind::Goto { target } => Some(Some(target)),
TerminatorKind::Return => Some(None),
TerminatorKind::Assert { ref cond, expected: false, target, .. } => {
let p = match cond {
mir::Operand::Copy(p) | mir::Operand::Move(p) => p,
@ -243,14 +238,28 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> {
if let &[mir::ProjectionElem::Field(ONE_FIELD, _)] = p.projection.as_ref() {
// Only allow asserts checking the result of a checked operation.
if self.checked_op_locals.contains(p.local) {
block = &self.body.basic_blocks()[target];
continue;
return Some(Some(target));
}
}
return None;
None
}
_ => return None,
_ => None,
}
}
fn build(mut self) -> Option<&'tcx [Node<'tcx>]> {
let mut block = &self.body.basic_blocks()[mir::START_BLOCK];
loop {
debug!("AbstractConstBuilder: block={:?}", block);
for stmt in block.statements.iter() {
self.build_statement(stmt)?;
}
if let Some(next) = self.build_terminator(block.terminator())? {
block = &self.body.basic_blocks()[next];
} else {
return Some(self.tcx.arena.alloc_from_iter(self.nodes));
}
}
}
@ -261,11 +270,11 @@ pub(super) fn mir_abstract_const<'tcx>(
tcx: TyCtxt<'tcx>,
def: ty::WithOptConstParam<LocalDefId>,
) -> Option<&'tcx [Node<'tcx>]> {
if !tcx.features().const_evaluatable_checked {
None
} else {
if tcx.features().const_evaluatable_checked {
let body = tcx.mir_const(def).borrow();
AbstractConstBuilder::new(tcx, &body)?.build()
} else {
None
}
}