bjoernager/rust
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Add UnwindAction::Unreachable

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This also makes eval machine's `StackPopUnwind`
redundant so that is replaced.
This commit is contained in:
Gary Guo 2022-10-10 19:50:49 +01:00
parent daeb844e0c
commit 5e6ed132fa
23 changed files with 160 additions and 149 deletions
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25
compiler/rustc_const_eval/src/interpret/eval_context.rs
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@ -139,17 +139,6 @@ pub struct FrameInfo<'tcx> {
pub lint_root: Option<hir::HirId>,
}
/// Unwind information.
#[derive(Clone, Copy, Eq, PartialEq, Debug)]
pub enum StackPopUnwind {
/// The cleanup block.
Cleanup(mir::BasicBlock),
/// No cleanup needs to be done.
Skip,
/// Unwinding is not allowed (UB).
NotAllowed,
}
#[derive(Clone, Copy, Eq, PartialEq, Debug)] // Miri debug-prints these
pub enum StackPopCleanup {
/// Jump to the next block in the caller, or cause UB if None (that's a function
@ -157,7 +146,7 @@ pub enum StackPopCleanup {
/// we can validate it at that layout.
/// `ret` stores the block we jump to on a normal return, while `unwind`
/// stores the block used for cleanup during unwinding.
Goto { ret: Option<mir::BasicBlock>, unwind: StackPopUnwind },
Goto { ret: Option<mir::BasicBlock>, unwind: mir::UnwindAction },
/// The root frame of the stack: nowhere else to jump to.
/// `cleanup` says whether locals are deallocated. Static computation
/// wants them leaked to intern what they need (and just throw away
@ -735,16 +724,16 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// *Unwind* to the given `target` basic block.
/// Do *not* use for returning! Use `return_to_block` instead.
///
/// If `target` is `StackPopUnwind::Skip`, that indicates the function does not need cleanup
/// If `target` is `UnwindAction::Continue`, that indicates the function does not need cleanup
/// during unwinding, and we will just keep propagating that upwards.
///
/// If `target` is `StackPopUnwind::NotAllowed`, that indicates the function does not allow
/// If `target` is `UnwindAction::Unreachable`, that indicates the function does not allow
/// unwinding, and doing so is UB.
pub fn unwind_to_block(&mut self, target: StackPopUnwind) -> InterpResult<'tcx> {
pub fn unwind_to_block(&mut self, target: mir::UnwindAction) -> InterpResult<'tcx> {
self.frame_mut().loc = match target {
StackPopUnwind::Cleanup(block) => Left(mir::Location { block, statement_index: 0 }),
StackPopUnwind::Skip => Right(self.frame_mut().body.span),
StackPopUnwind::NotAllowed => {
mir::UnwindAction::Cleanup(block) => Left(mir::Location { block, statement_index: 0 }),
mir::UnwindAction::Continue => Right(self.frame_mut().body.span),
mir::UnwindAction::Unreachable => {
throw_ub_format!("unwinding past a stack frame that does not allow unwinding")
}
};