Struct evmil::bytecode::Builder

pub struct Builder { /* private fields */ }

Mechanism for constructing a bytecode Assembly by allowing instructions to be patched before the final assembly is built. For example, consider the problem of constructing an assembly from this assembly language:

   push lab
   jump
   stop
lab:
   jumpdest

The challenge is that, when constructing the push lab instruction, we don’t yet know the instruction offset of lab. A Builder allows one to register a label and create an instance of PUSH which is later patched to ensure it has the correct instruction offset.

Implementations

impl Builder

pub fn new() -> Self

pub fn len(&self) -> usize

Determine the number of instructions currently pushed into this builder.

pub fn is_empty(&self) -> bool

Returns true if no instructions have yet been pushed into this builder.

pub fn get_label(&mut self, label: &str) -> usize

Get the label index associated with a particular label. If such an index does not already exist, then a new label is registered.

pub fn set_label(&mut self, label: &str, offset: usize) -> Result<(), ()>

Set the instruction offset associated with a given label. If the label does not yet exist (i.e. as not yet been assigned an index), then it will be.

pub fn mark_label(&mut self, label: &str) -> Result<(), ()>

Mark a label at the current instruction offset. If the label does not yet exist (i.e. as not yet been assigned an index), then it will be.

pub fn push_labeled(&mut self, insn: Instruction)

Push a new instruction onto the builder.

pub fn push(&mut self, insn: Instruction)

Push a new instruction onto the builder.

pub fn to_insns(self) -> Vec<Instruction>

Construct the final assembly by patching all labels used within instructions.