Module: Ibex::Codegen::GeneratedActionABI

Defined in:
lib/ibex/codegen/generated_action_abi.rb

Overview

Selects the smallest generated semantic-action ABI that preserves the action's declared inputs. rubocop:disable Metrics/ModuleLength -- ABI proof and source rewriting must evolve together.

Defined Under Namespace

Classes: Cache

Class Method Summary collapse

Class Method Details

.borrowed_values?(production, analysis: self) ⇒ Boolean

The direct runtime can share one reduction-values array with an action and a hook installed by that action only when the action cannot mutate or retain the array itself. Element reads and parallel assignment copy values out without exposing the container.

Returns:

  • (Boolean) 


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# File 'lib/ibex/codegen/generated_action_abi.rb', line 86

def borrowed_values?(production, analysis: self)
  return false unless analysis.values_only?(production)

  action = production.action
  return false unless action

  maximum = production.rhs.length
  source = ActionLocations.new(action.code, maximum: maximum, location: action.location).rewrite
  return true if simple_indexed_values_action?(source)

  require "ripper"
  syntax = Object.const_get(:Ripper).__send__(:sexp, source)
  !syntax.nil? && read_only_value_references?(syntax)
end

.positional_action_source(production, analysis: self) ⇒ Object

Return semantic source rewritten for zero-to-four positional RHS arguments, or nil when the values container remains observable.



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# File 'lib/ibex/codegen/generated_action_abi.rb', line 104

def positional_action_source(production, analysis: self)
  return nil unless analysis.values_only?(production)
  return nil unless production.rhs.length <= 4

  action = production.action
  return "" unless action
  return nil unless analysis.borrowed_values?(production)

  parameters = Array.new(production.rhs.length) { |index| "v#{index}" }
  return nil if action.named_refs.any? { |reference| parameters.include?(reference[:name]) }

  maximum = production.rhs.length
  source = ActionLocations.new(action.code, maximum: maximum, location: action.location).rewrite
  simple = fast_positional_action_source(source, parameters)
  return simple unless simple.nil?

  require "ripper"
  tokens = Object.const_get(:Ripper).__send__(:lex, source)
  return nil unless tokens.map { |_position, _event, token, _state| token }.join == source

  rewrite_positional_values(tokens, parameters)
end

.positional_values?(production) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ibex/codegen/generated_action_abi.rb', line 137

def positional_values?(production)
  !positional_action_source(production).nil?
end

.values_only?(production) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ibex/codegen/generated_action_abi.rb', line 69

def values_only?(production)
  return false if production.action&.composition

  action = production.action
  return true unless action
  return false if action.context_length.positive?

  maximum = production.rhs.length
  locations = ActionLocations.new(action.code, maximum: maximum, location: action.location)
  !locations.references? && !references_legacy_parameter?(action.code)
end