Module: Mirah::JVM::MethodLookup

Included in:
Compiler::JVMBytecode, Types::Type
Defined in:
lib/mirah/jvm/method_lookup.rb

Instance Method Summary collapse

Instance Method Details

#each_is_exact(incoming, target) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 269

def each_is_exact(incoming, target)
  incoming.zip(target).all? { |in_type, target_type| target_type == in_type }
end

#each_is_exact_or_subtype_or_convertible(incoming, target) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 273

def each_is_exact_or_subtype_or_convertible(incoming, target)
  incoming.zip(target).each do |in_type, target_type|

    # exact match
    next if target_type == in_type

    unless target_type.respond_to?(:primitive?) && in_type.respond_to?(:primitive?)
      puts "Huh?"
    end

    # primitive is safely convertible
    if target_type.primitive?
      if in_type.primitive?
        next if primitive_convertible? in_type, target_type
      end
      return false
    end

    # object type is assignable
    compatible = if target_type.respond_to?(:compatible?)
      target_type.compatible? in_type
    else
      target_type.assignable_from? in_type
    end
    return false unless compatible
  end
  return true
end

#field_lookup(mapped_params, mapped_type, meta, name, scope) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 219

def field_lookup(mapped_params, mapped_type, meta, name, scope)
  log("Attempting #{meta ? 'static' : 'instance'} field lookup for '#{name}' on class #{mapped_type}")
  # if we get to this point, the potentials do not match, so we ignore them


  # search for a field of the given name
  if name =~ /_set$/
    # setter
    setter = true
    name = name[0..-5]
    field = mapped_type.field_setter(name)
  else
    # getter
    setter = false

    # field accesses don't take arguments
    return if mapped_params.size > 0
    field = mapped_type.field_getter(name)
  end

  return nil unless field

  if (meta && !field.static?) ||
      (!meta && field.static?)
    return nil
  end

  # check accessibility
  # TODO: protected field access check appropriate to current type
  if setter
    if field.final?
      log "cannot set final field '#{name}' on class #{mapped_type}"
      return nil
    end
  end
  unless field.public?
    from = " from #{scope.selfType.resolve.name}" if scope
    log "cannot access field '#{name}' on class #{mapped_type}#{from}"
    return nil
  end

  field
end

#find_jls(mapped_type, name, mapped_params, macro_params, meta, constructor, scope = nil) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 97

def find_jls(mapped_type, name, mapped_params, macro_params, meta, constructor, scope=nil)
  interfaces = []
  by_name = if constructor
    mapped_type.unmeta.declared_constructors
  elsif meta
    mapped_type.find_callable_static_methods(name)
  else
    mapped_type.find_callable_methods(name)
  end
  method = find_jls2(mapped_type, name, mapped_params, meta, by_name, true, scope)
  return method if (constructor || macro_params.nil?)
  macros = mapped_type.find_callable_macros(name)
  if macros.size != 0
    log "Found potential macro match for #{mapped_type.name}.#{name}(#{macro_params.map(&:full_name).join ', '})"
    macro = find_jls2(mapped_type, name, macro_params, meta, macros, false, scope)
  end
  if macro && method
    raise "Ambiguous targets invoking #{mapped_type}.#{name}:\n#{macro} and #{method}"
  end
  macro || method
end

#find_jls2(mapped_type, name, mapped_params, meta, by_name, include_fields = true, scope = nil) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 119

def find_jls2(mapped_type, name, mapped_params, meta, by_name, include_fields=true, scope=nil)
  return nil if mapped_params.any? {|p| p.nil? || p.isError}

  # filter by arity, varargs
  by_name_and_arity = by_name.select {|m| m.argument_types.size == mapped_params.size }

  phase1_methods = phase1(mapped_params, by_name_and_arity)

  if phase1_methods.size > 1
    method_list = phase1_methods.map do |m|
      case m.member
      when BiteScript::ASM::MethodMirror
        m.member.inspect
      else
        "#{m.name}(#{m.parameter_types.map(&:name).join(', ')})"
      end
    end.join("\n")
    raise "Ambiguous targets invoking #{mapped_type}.#{name}:\n#{method_list}"
  end

  phase1_methods[0] ||
    phase2(mapped_params, by_name) ||
    phase3(mapped_params, by_name)[0] ||
    (include_fields &&
      (field_lookup(mapped_params, mapped_type, meta, name, scope) ||
       inner_class(mapped_params, mapped_type, meta, name)))
end

#find_method(mapped_type, name, mapped_params, macro_params, meta, scope = nil, &block) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 31

def find_method(mapped_type, name, mapped_params, macro_params, meta, scope=nil, &block)
  if mapped_type.error?
    raise "WTF?!?"
  end

  if name == 'new' && meta # we're calling SomeClass.new
    name = "<init>"
    constructor = true
    mapped_type = mapped_type.unmeta
    meta = false
  elsif name == 'new' && !meta # we're calling some_instance.new
    constructor = false
  elsif name == '<init>' && !meta # how do we get here?
    constructor = true
  elsif name == 'initialize' && !meta && scope
    context = scope.context
    if context.kind_of?(ConstructorDefinition) || context.findAncesor(ConstructorDefinition.class)
      constructor = true
      name = '<init>'
    end
  end

  if block_given?
    if constructor
      mapped_type.add_method_listener('initialize') {block.call(find_method2(mapped_type.meta, 'new', mapped_params, macro_params, true))}
    else
      mapped_type.add_method_listener(name) {block.call(find_method2(mapped_type, name, mapped_params, macro_params, meta))}
    end
    block.call(find_method(mapped_type, name, mapped_params, macro_params, meta))
    return
  end

  begin
    unless mapped_params.any? {|p| p.nil? || p.isError}
      if constructor
        method = mapped_type.constructor(*mapped_params)
      else
        method = mapped_type.java_method(name, *mapped_params)
      end
    end
  rescue NameError => ex
    # TODO return nil instead of raising an exception if the method doesn't exist.
    raise ex unless ex.message =~ /#{Regexp.quote(mapped_type.name)}\.#{Regexp.quote(name)}|No constructor #{Regexp.quote(mapped_type.name)}/
  end

  macro = mapped_type.macro(name, macro_params)
  if method && macro
    method = nil  # Need full lookup to determine precedence.
  elsif method.nil? && macro
    method = macro
  elsif method.nil?
    # exact args failed, do a deeper search
    log "No exact match for #{mapped_type.name}.#{name}(#{mapped_params.map(&:name).join ', '})" if mapped_params.all?

    method = find_jls(mapped_type, name, mapped_params, macro_params, meta, constructor, scope)

    unless method
      log "Failed to locate method #{mapped_type.name}.#{name}(#{mapped_params.map(&:name).join ', '})" if mapped_params.all?
      return nil
    end
  end

  log "Found method #{method.declaring_class.name}.#{name}(#{method.argument_types.map(&:name).join ', '}) from #{mapped_type.name}" if method
  return method
end

#find_method2(mapped_type, name, mapped_params, macro_params, meta, scope = nil, &block) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 21

def find_method2(mapped_type, name, mapped_params, macro_params, meta, scope=nil, &block)
  find_method(mapped_type, name, mapped_params, macro_params, meta, scope, &block)
rescue NameError => ex
  raise ex unless ex.message.include?(name)
  if block_given?
    block.call(ex)
  end
  ex
end

#inner_class(params, type, meta, name) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 263

def inner_class(params, type, meta, name)
  return unless params.empty? && meta
  log("Attempting inner class lookup for '#{name}' on #{type}")
  type.inner_class_getter(name)
end

#is_more_specific?(potential, current) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mirah/jvm/method_lookup.rb', line 188

def is_more_specific?(potential, current)
  each_is_exact_or_subtype_or_convertible(potential, current)
end

#phase1(mapped_params, potentials) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 147

def phase1(mapped_params, potentials)
  log "Beginning JLS phase 1 search with params (#{mapped_params.map(&:name).join ', '})"

  # cycle through methods looking for more specific matches; gather matches of equal specificity
  methods = potentials.inject([]) do |currents, potential|
    method_params = potential.argument_types
    next currents unless method_params.all?

    # exact match always wins; duplicates not possible
    if each_is_exact(mapped_params, method_params)
      return [potential]
    end

    # otherwise, check for potential match and compare to current
    # TODO: missing ambiguity check; picks first method of equal specificity
    # Picking the first method means we prefer methods from the child class,
    # which is important if the parent class is not accessible (like AbstractStringBuilder).
    if each_is_exact_or_subtype_or_convertible(mapped_params, method_params)
      if !currents.empty?
        if is_more_specific?(currents[0].argument_types, potential.argument_types)
          # currents are better, try next potential
          #next
        elsif is_more_specific?(potential.argument_types, currents[0].argument_types)
          # potential is better, dump all currents
          currents = [potential]
        else
          # equal specificity, append to currents
          currents << potential
        end
      else
        # no previous matches, use potential
        currents = [potential]
      end
    end

    currents
  end

  methods
end

#phase2(mapped_params, potentials) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 192

def phase2(mapped_params, potentials)
  nil
end

#phase3(mapped_params, potentials) ⇒ Object 



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# File 'lib/mirah/jvm/method_lookup.rb', line 196

def phase3(mapped_params, potentials)
  potential_varargs = potentials.select{|m| m.respond_to?(:varargs?) && m.varargs? }
  methods = potential_varargs.inject([]) do |currents, potential|
    method_params = potential.argument_types
    # match n-1 params of potential
    non_varargs_params, possible_varargs_params = mapped_params.partition.with_index{|param,i| i < method_params.size-1}
    
    vararg_types = possible_varargs_params.size.times.map{ method_params.last.component_type }
    
    if each_is_exact(non_varargs_params, method_params[0..-2]) &&
        each_is_exact(possible_varargs_params, vararg_types)
      return [potential]
    end
    
    if each_is_exact_or_subtype_or_convertible(non_varargs_params, method_params[0..-2]) &&
        each_is_exact_or_subtype_or_convertible(possible_varargs_params, vararg_types)
      currents << potential
    end

    currents
  end
end

#primitive_convertible?(in_type, target_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mirah/jvm/method_lookup.rb', line 302

def primitive_convertible?(in_type, target_type)
  in_type.convertible_to?(target_type)
end