Class: Hone::Patterns::DynamicIvarGet

Inherits:
Base
  • Object
show all
Defined in:
lib/hone/patterns/dynamic_ivar_get.rb

Overview

Pattern: instance_variable_get("@#name")

Often paired with dynamic instance_variable_set. Suggests the code is using ivars as a dynamic key-value store, which hurts JIT.

Impact: Significant with YJIT, none without

Instance Attribute Summary

Attributes inherited from Base

#findings

Instance Method Summary collapse

Methods inherited from Base

#add_finding, inherited, #initialize, scan_file

Constructor Details

This class inherits a constructor from Hone::Patterns::Base

Instance Method Details

#visit_call_node(node) ⇒ Object 



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# File 'lib/hone/patterns/dynamic_ivar_get.rb', line 15

def visit_call_node(node)
  super

  return unless node.name == :instance_variable_get

  first_arg = node.arguments&.arguments&.first
  return unless first_arg
  return unless first_arg.is_a?(Prism::InterpolatedStringNode) ||
    first_arg.is_a?(Prism::LocalVariableReadNode)

  add_finding(
    node,
    message: "Dynamic instance_variable_get suggests ivars used as key-value store. Use a Hash instead for better YJIT performance.",
    speedup: "Significant with YJIT, none without"
  )
end