pub enum UnwindOperation {
PushNonVolatile(Register),
Alloc(u32),
SetFPRegister,
SaveNonVolatile(Register, StackFrameOffset),
SaveXMM(Register, StackFrameOffset),
Epilog,
SaveXMM128(Register, StackFrameOffset),
PushMachineFrame(bool),
Noop,
}
Expand description
An unwind operation corresponding to code in the function prolog.
Unwind operations can be used to reverse the effects of the function prolog and restore register values of parent stack frames that have been saved to the stack.
Variants
PushNonVolatile(Register)
Push a nonvolatile integer register, decrementing RSP
by 8.
Alloc(u32)
Allocate a fixed-size area on the stack.
SetFPRegister
Establish the frame pointer register by setting the register to some offset of the current RSP. The use of an offset permits establishing a frame pointer that points to the middle of the fixed stack allocation, helping code density by allowing more accesses to use short instruction forms.
SaveNonVolatile(Register, StackFrameOffset)
Save a nonvolatile integer register on the stack using a MOV instead of a PUSH. This code is primarily used for shrink-wrapping, where a nonvolatile register is saved to the stack in a position that was previously allocated.
SaveXMM(Register, StackFrameOffset)
Save the lower 64 bits of a nonvolatile XMM register on the stack.
Epilog
Describes the function epilog.
This operation has been introduced with unwind info version 2 and is not implemented yet.
SaveXMM128(Register, StackFrameOffset)
Save all 128 bits of a nonvolatile XMM register on the stack.
PushMachineFrame(bool)
Push a machine frame. This is used to record the effect of a hardware interrupt or exception. Depending on the error flag, this frame has two different layouts.
This unwind code always appears in a dummy prolog, which is never actually executed but instead appears before the real entry point of an interrupt routine, and exists only to provide a place to simulate the push of a machine frame. This operation records that simulation, which indicates the machine has conceptually done this:
- Pop RIP return address from top of stack into
temp
$ss
, Push old$rsp
,$rflags
,$cs
,temp
- If error flag is
true
, push the error code
Without an error code, RSP was incremented by 40
and the following was frame pushed:
Offset | Value |
---|---|
RSP + 32 | $ss |
RSP + 24 | old $rsp |
RSP + 16 | $rflags |
RSP + 8 | $cs |
RSP + 0 | $rip |
With an error code, RSP was incremented by 48
and the following was frame pushed:
Offset | Value |
---|---|
RSP + 40 | $ss |
RSP + 32 | old $rsp |
RSP + 24 | $rflags |
RSP + 16 | $cs |
RSP + 8 | $rip |
RSP + 0 | error code |
Noop
A reserved operation without effect.
Trait Implementations
sourceimpl Clone for UnwindOperation
impl Clone for UnwindOperation
sourcefn clone(&self) -> UnwindOperation
fn clone(&self) -> UnwindOperation
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl Debug for UnwindOperation
impl Debug for UnwindOperation
sourceimpl PartialEq<UnwindOperation> for UnwindOperation
impl PartialEq<UnwindOperation> for UnwindOperation
sourcefn eq(&self, other: &UnwindOperation) -> bool
fn eq(&self, other: &UnwindOperation) -> bool
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
sourcefn ne(&self, other: &UnwindOperation) -> bool
fn ne(&self, other: &UnwindOperation) -> bool
This method tests for !=
.
impl Copy for UnwindOperation
impl Eq for UnwindOperation
impl StructuralEq for UnwindOperation
impl StructuralPartialEq for UnwindOperation
Auto Trait Implementations
impl RefUnwindSafe for UnwindOperation
impl Send for UnwindOperation
impl Sync for UnwindOperation
impl Unpin for UnwindOperation
impl UnwindSafe for UnwindOperation
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcepub fn borrow_mut(&mut self) -> &mut T
pub fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcepub fn to_owned(&self) -> T
pub fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
sourcepub fn clone_into(&self, target: &mut T)
pub fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more