Enum VariableOrigin 

pub enum VariableOrigin {
    Argument(u16),
    Local(u16),
    Phi,
    EntryLiveIn,
}

The origin of an SSA variable - where it came from in the original CIL.

This enum tracks the semantic source of each SSA variable, which is useful for debugging, optimization decisions, and mapping back to source code.

CIL Variable Mapping

CIL Instruction	Variable Origin
ldarg.N, ldarg.s, ldarg	Argument(N)
ldloc.N, ldloc.s, ldloc	Local(N)
Stack operations (add, call, etc.)	Local(num_locals + K)
Phi node result	Phi

Machine-code front ends

The four variants above describe a CIL method, which has a declared signature and a declared local table. A machine-code lifter has neither: a register read before any write in the function body is a value the caller supplied, but its position in the (unrecovered) signature is unknown at lift time. That case is EntryLiveIn — not Argument, which would assert a signature position the lifter cannot yet know.

Examples

use analyssa::ir::variable::VariableOrigin;

let arg_origin = VariableOrigin::Argument(0);  // First method argument
let local_origin = VariableOrigin::Local(2);   // Third local variable
let phi_origin = VariableOrigin::Phi;          // From phi node
let live_in = VariableOrigin::EntryLiveIn;     // Caller-supplied, position unknown

Variants

Argument(u16)

Method argument (parameter).

The index corresponds to the argument’s position in the method signature. For instance methods, argument 0 is this.

Local(u16)

Local variable declared in the method.

The index corresponds to the local’s position in the local variable signature (accessed via ldloc/stloc). Local(idx) always refers to a real CIL local. Stack temporaries and other synthetics use Phi origin instead.

Phi

Result of a phi node at a control flow merge.

Phi nodes are synthetic - they don’t correspond to any CIL instruction but rather represent the merging of values from different control flow paths.

EntryLiveIn

A value live on entry to the function, supplied by the caller, whose position in the signature is not known.

Produced by machine-code front ends for a storage location (typically a register) that is read before the function body ever writes it. Like Argument it needs no definition in the body — the verifier treats it as entry-defined — but unlike Argument it makes no claim about argument position, because at lift time the calling convention has not been recovered.

ABI recovery may later reclassify such a variable as a real Argument(n); until it does, this is the honest description.

Implementations

impl VariableOrigin

pub const fn is_argument(&self) -> bool

Returns true if this is an argument origin.

pub const fn is_local(&self) -> bool

Returns true if this is a local variable origin.

pub const fn is_phi(&self) -> bool

Returns true if this is a phi node result.

pub const fn is_entry_live_in(&self) -> bool

Returns true if this is a caller-supplied value live on function entry.

pub const fn is_caller_supplied(&self) -> bool

Returns true if the caller supplies this value, so it needs no definition in the function body.

True for both Argument (position known) and EntryLiveIn (position not yet recovered).

pub const fn argument_index(&self) -> Option<u16>

Returns the argument index if this is an argument origin.

pub const fn local_index(&self) -> Option<u16>

Returns the local index if this is a local variable origin.

Trait Implementations

impl Clone for VariableOrigin

fn clone(&self) -> VariableOrigin

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for VariableOrigin

impl Debug for VariableOrigin

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

Formats the value using the given formatter.

impl Display for VariableOrigin

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

Formats the value using the given formatter.

impl Eq for VariableOrigin

impl Hash for VariableOrigin

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

where __H: Hasher,

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 VariableOrigin

fn cmp(&self, other: &VariableOrigin) -> 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.

impl PartialEq for VariableOrigin

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for VariableOrigin

fn partial_cmp(&self, other: &VariableOrigin) -> 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 VariableOrigin