Enum Hook 

pub enum Hook {
    Platform,
    Early,
    Late,
}

Where the call -pg puts at the top of every function goes, which -mfentry chooses.

Two conventions for one job, and the difference is what the hook can see when it runs. See rucc_target::Trace for what each of them is and why a kernel needs the earlier one.

A third answer, because a command line that named neither has not asked a question: the platform’s own answer is the one it gets, and that is a fact about the target rather than about the flags, so it is settled where the target is known and not here.

Variants

Platform

Whichever the platform puts first, which is what a command line that said neither gets.

Early

-mfentry. In front of the prologue, so the return address is the top thing on the stack and the arguments are still where the call left them.

Late

-mno-fentry. Once the frame is taken, so the hook can walk back through the frame pointer, which is why a function that has this one is given a frame pointer whatever else was said.

Implementations

impl Hook

pub const fn as_str(self) -> &'static str

That answer as it is written on a command line, which is what --print-config reports.

pub const fn early(self, fentry: bool) -> bool

Whether the call goes in front of the prologue, given what the platform puts first.

Trait Implementations

impl Clone for Hook

fn clone(&self) -> Hook

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Hook

impl Debug for Hook

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

Formats the value using the given formatter.

impl Default for Hook

fn default() -> Hook

Returns the “default value” for a type.

impl Display for Hook

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

Formats the value using the given formatter.

impl Eq for Hook

impl Hash for Hook

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Hook

fn cmp(&self, other: &Hook) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Hook

fn eq(&self, other: &Hook) -> bool

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Hook

fn partial_cmp(&self, other: &Hook) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for Hook