Enum gimli::read::RegisterRule

#[non_exhaustive]
pub enum RegisterRule<T: ReaderOffset> {
    Undefined,
    SameValue,
    Offset(i64),
    ValOffset(i64),
    Register(Register),
    Expression(UnwindExpression<T>),
    ValExpression(UnwindExpression<T>),
    Architectural,
    Constant(u64),
}

An entry in the abstract CFI table that describes how to find the value of a register.

“The register columns contain rules that describe whether a given register has been saved and the rule to find the value for the register in the previous frame.”

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Undefined

A register that has this rule has no recoverable value in the previous frame. (By convention, it is not preserved by a callee.)

SameValue

This register has not been modified from the previous frame. (By convention, it is preserved by the callee, but the callee has not modified it.)

Offset(i64)

“The previous value of this register is saved at the address CFA+N where CFA is the current CFA value and N is a signed offset.”

ValOffset(i64)

“The previous value of this register is the value CFA+N where CFA is the current CFA value and N is a signed offset.”

Register(Register)

“The previous value of this register is stored in another register numbered R.”

Expression(UnwindExpression<T>)

“The previous value of this register is located at the address produced by executing the DWARF expression.”

ValExpression(UnwindExpression<T>)

“The previous value of this register is the value produced by executing the DWARF expression.”

Architectural

“The rule is defined externally to this specification by the augmenter.”

Constant(u64)

This is a pseudo-register with a constant value.

Trait Implementations

impl<T: Clone + ReaderOffset> Clone for RegisterRule<T>

fn clone(&self) -> RegisterRule<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + ReaderOffset> Debug for RegisterRule<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: PartialEq + ReaderOffset> PartialEq for RegisterRule<T>

fn eq(&self, other: &RegisterRule<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Eq + ReaderOffset> Eq for RegisterRule<T>

impl<T: ReaderOffset> StructuralPartialEq for RegisterRule<T>