diff options
| -rw-r--r-- | src/librustc_mir/interpret/eval_context.rs | 31 | ||||
| -rw-r--r-- | src/librustc_mir/interpret/machine.rs | 12 | ||||
| -rw-r--r-- | src/librustc_mir/interpret/mod.rs | 2 |
3 files changed, 19 insertions, 26 deletions
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index 9b28b7a20c0..0d43e4759f7 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -21,7 +21,7 @@ use rustc_span::source_map::{self, Span, DUMMY_SP}; use super::{ Immediate, MPlaceTy, Machine, MemPlace, MemPlaceMeta, Memory, OpTy, Operand, Place, PlaceTy, - ScalarMaybeUndef, StackPopInfo, + ScalarMaybeUndef, StackPopJump, }; pub struct InterpCx<'mir, 'tcx, M: Machine<'mir, 'tcx>> { @@ -623,23 +623,15 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ::log_settings::settings().indentation -= 1; let frame = self.stack.pop().expect("tried to pop a stack frame, but there were none"); - let stack_pop_info = M::stack_pop(self, frame.extra, unwinding)?; - if let (false, StackPopInfo::StopUnwinding) = (unwinding, stack_pop_info) { - bug!("Attempted to stop unwinding while there is no unwinding!"); - } // Now where do we jump next? - // Determine if we leave this function normally or via unwinding. - let cur_unwinding = - if let StackPopInfo::StopUnwinding = stack_pop_info { false } else { unwinding }; - // Usually we want to clean up (deallocate locals), but in a few rare cases we don't. // In that case, we return early. We also avoid validation in that case, // because this is CTFE and the final value will be thoroughly validated anyway. let (cleanup, next_block) = match frame.return_to_block { StackPopCleanup::Goto { ret, unwind } => { - (true, Some(if cur_unwinding { unwind } else { ret })) + (true, Some(if unwinding { unwind } else { ret })) } StackPopCleanup::None { cleanup, .. } => (cleanup, None), }; @@ -647,7 +639,8 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { if !cleanup { assert!(self.stack.is_empty(), "only the topmost frame should ever be leaked"); assert!(next_block.is_none(), "tried to skip cleanup when we have a next block!"); - // Leak the locals, skip validation. + assert!(!unwinding, "tried to skip cleanup during unwinding"); + // Leak the locals, skip validation, skip machine hook. return Ok(()); } @@ -656,13 +649,13 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { self.deallocate_local(local.value)?; } - trace!( - "StackPopCleanup: {:?} StackPopInfo: {:?} cur_unwinding = {:?}", - frame.return_to_block, - stack_pop_info, - cur_unwinding - ); - if cur_unwinding { + if M::stack_pop(self, frame.extra, unwinding)? == StackPopJump::NoJump { + // The hook already did everything. + // We want to skip the `trace!` below, hence early return. + return Ok(()); + } + // Normal return. + if unwinding { // Follow the unwind edge. let unwind = next_block.expect("Encountered StackPopCleanup::None when unwinding!"); self.unwind_to_block(unwind); @@ -697,7 +690,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { "CONTINUING({}) {} (unwinding = {})", self.cur_frame(), self.frame().instance, - cur_unwinding + unwinding ); } diff --git a/src/librustc_mir/interpret/machine.rs b/src/librustc_mir/interpret/machine.rs index 366de6e5561..0e70e54ad85 100644 --- a/src/librustc_mir/interpret/machine.rs +++ b/src/librustc_mir/interpret/machine.rs @@ -17,16 +17,16 @@ use super::{ /// Data returned by Machine::stack_pop, /// to provide further control over the popping of the stack frame #[derive(Eq, PartialEq, Debug, Copy, Clone)] -pub enum StackPopInfo { +pub enum StackPopJump { /// Indicates that no special handling should be /// done - we'll either return normally or unwind /// based on the terminator for the function /// we're leaving. Normal, - /// Indicates that we should stop unwinding, - /// as we've reached a catch frame - StopUnwinding, + /// Indicates that we should *not* jump to the return/unwind address, as the callback already + /// took care of everything. + NoJump, } /// Whether this kind of memory is allowed to leak @@ -276,9 +276,9 @@ pub trait Machine<'mir, 'tcx>: Sized { _ecx: &mut InterpCx<'mir, 'tcx, Self>, _extra: Self::FrameExtra, _unwinding: bool, - ) -> InterpResult<'tcx, StackPopInfo> { + ) -> InterpResult<'tcx, StackPopJump> { // By default, we do not support unwinding from panics - Ok(StackPopInfo::Normal) + Ok(StackPopJump::Normal) } fn int_to_ptr( diff --git a/src/librustc_mir/interpret/mod.rs b/src/librustc_mir/interpret/mod.rs index a519f38e712..c3fd9682765 100644 --- a/src/librustc_mir/interpret/mod.rs +++ b/src/librustc_mir/interpret/mod.rs @@ -24,7 +24,7 @@ pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy}; pub use self::memory::{AllocCheck, FnVal, Memory, MemoryKind}; -pub use self::machine::{AllocMap, Machine, MayLeak, StackPopInfo}; +pub use self::machine::{AllocMap, Machine, MayLeak, StackPopJump}; pub use self::operand::{ImmTy, Immediate, OpTy, Operand, ScalarMaybeUndef}; |