bjoernager/rust
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interpret: remove LocalValue::Unallocated, add Operand::Uninit

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Operand::Uninit is an *allocated* operand that is fully uninitialized.
This lets us lazily allocate the actual backing store of *all* locals (no matter their ABI).

I also reordered things in pop_stack_frame at the same time.
I should probably have made that a separate commit...
This commit is contained in:
Ralf Jung 2022-07-02 16:24:42 -04:00
parent 049308cf8b
commit 8ef0caa23c
8 changed files with 179 additions and 175 deletions
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19
compiler/rustc_const_eval/src/interpret/machine.rs
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@ -14,8 +14,7 @@ use rustc_target::spec::abi::Abi;
use super::{
AllocId, AllocRange, Allocation, ConstAllocation, Frame, ImmTy, InterpCx, InterpResult,
LocalValue, MemPlace, MemoryKind, OpTy, Operand, PlaceTy, Pointer, Provenance, Scalar,
StackPopUnwind,
MemoryKind, OpTy, Operand, PlaceTy, Pointer, Provenance, Scalar, StackPopUnwind,
};
/// Data returned by Machine::stack_pop,
@ -226,11 +225,13 @@ pub trait Machine<'mir, 'tcx>: Sized {
/// Since reading a ZST is not actually accessing memory or locals, this is never invoked
/// for ZST reads.
#[inline]
fn access_local(
_ecx: &InterpCx<'mir, 'tcx, Self>,
frame: &Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>,
fn access_local<'a>(
frame: &'a Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>,
local: mir::Local,
) -> InterpResult<'tcx, Operand<Self::PointerTag>> {
) -> InterpResult<'tcx, &'a Operand<Self::PointerTag>>
where
'tcx: 'mir,
{
frame.locals[local].access()
}
@ -242,7 +243,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
frame: usize,
local: mir::Local,
) -> InterpResult<'tcx, Result<&'a mut LocalValue<Self::PointerTag>, MemPlace<Self::PointerTag>>>
) -> InterpResult<'tcx, &'a mut Operand<Self::PointerTag>>
where
'tcx: 'mir,
{
@ -418,12 +419,14 @@ pub trait Machine<'mir, 'tcx>: Sized {
}
/// Called immediately after a stack frame got popped, but before jumping back to the caller.
/// The `locals` have already been destroyed!
fn after_stack_pop(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_frame: Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>,
_unwinding: bool,
unwinding: bool,
) -> InterpResult<'tcx, StackPopJump> {
// By default, we do not support unwinding from panics
assert!(!unwinding);
Ok(StackPopJump::Normal)
}
}