user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

deallocate locals before validation, to catch dangling references

Browse source
This commit is contained in:
Ralf Jung 2018-11-17 14:51:45 +01:00
parent 1d808d106b
commit bcf82efe08
1 changed files with 19 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

30
src/librustc_mir/interpret/eval_context.rs
View file

@ -492,7 +492,24 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
let frame = self.stack.pop().expect(
"tried to pop a stack frame, but there were none",
);
// Validate the return value.
// Abort early if we do not want to clean up: We also avoid validation in that case,
// because this is CTFE and the final value will be thoroughly validated anyway.
match frame.return_to_block {
StackPopCleanup::Goto(_) => {},
StackPopCleanup::None { cleanup } => {
if !cleanup {
assert!(self.stack.is_empty(), "only the topmost frame should ever be leaked");
// Leak the locals, skip validation.
return Ok(());
}
}
}
// Deallocate all locals that are backed by an allocation.
for local in frame.locals {
self.deallocate_local(local)?;
}
// Validate the return value. Do this after deallocating so that we catch dangling
// references.
if let Some(return_place) = frame.return_place {
if M::enforce_validity(self) {
// Data got changed, better make sure it matches the type!
@ -518,16 +535,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
StackPopCleanup::Goto(block) => {
self.goto_block(block)?;
}
StackPopCleanup::None { cleanup } => {
if !cleanup {
// Leak the locals.
return Ok(());
}
}
}
// Deallocate all locals that are backed by an allocation.
for local in frame.locals {
self.deallocate_local(local)?;
StackPopCleanup::None { .. } => {}
}
if self.stack.len() > 1 { // FIXME should be "> 0", printing topmost frame crashes rustc...