Current File : //opt/alt/ruby33/share/ruby/ruby_vm/rjit/c_pointer.rb
module RubyVM::RJIT
# Every class under this namespace is a pointer. Even if the type is
# immediate, it shouldn't be dereferenced until `*` is called.
module CPointer
# Note: We'd like to avoid alphabetic method names to avoid a conflict
# with member methods. to_i and to_s are considered an exception.
class Struct
# @param name [String]
# @param sizeof [Integer]
# @param members [Hash{ Symbol => [RubyVM::RJIT::CType::*, Integer, TrueClass] }]
def initialize(addr, sizeof, members)
@addr = addr
@sizeof = sizeof
@members = members
end
# Get a raw address
def to_i
@addr
end
# Serialized address for generated code
def to_s
"0x#{@addr.to_s(16)}"
end
# Pointer diff
def -(struct)
raise ArgumentError if self.class != struct.class
(@addr - struct.to_i) / @sizeof
end
# Primitive API that does no automatic dereference
# TODO: remove this?
# @param member [Symbol]
def [](member)
type, offset = @members.fetch(member)
type.new(@addr + offset / 8)
end
private
# @param member [Symbol]
# @param value [Object]
def []=(member, value)
type, offset = @members.fetch(member)
type[@addr + offset / 8] = value
end
# @param size [Integer]
# @param members [Hash{ Symbol => [Integer, RubyVM::RJIT::CType::*] }]
def self.define(size, members)
Class.new(self) do
# Return the size of this type
define_singleton_method(:size) { size }
# Return the offset to a field
define_singleton_method(:offsetof) do |field, *fields|
member, offset = members.fetch(field)
offset /= 8
unless fields.empty?
offset += member.offsetof(*fields)
end
offset
end
# Return member names
define_singleton_method(:members) { members.keys }
define_method(:initialize) do |addr = nil|
if addr.nil? # TODO: get rid of this feature later
addr = Fiddle.malloc(size)
end
super(addr, size, members)
end
members.each do |member, (type, offset, to_ruby)|
# Intelligent API that does automatic dereference
define_method(member) do
value = self[member]
if value.respond_to?(:*)
value = value.*
end
if to_ruby
value = C.to_ruby(value)
end
value
end
define_method("#{member}=") do |value|
if to_ruby
value = C.to_value(value)
end
self[member] = value
end
end
end
end
end
# Note: We'd like to avoid alphabetic method names to avoid a conflict
# with member methods. to_i is considered an exception.
class Union
# @param _name [String] To be used when it starts defining a union pointer class
# @param sizeof [Integer]
# @param members [Hash{ Symbol => RubyVM::RJIT::CType::* }]
def initialize(addr, sizeof, members)
@addr = addr
@sizeof = sizeof
@members = members
end
# Get a raw address
def to_i
@addr
end
# Move addr to access this pointer like an array
def +(index)
raise ArgumentError unless index.is_a?(Integer)
self.class.new(@addr + index * @sizeof)
end
# Pointer diff
def -(union)
raise ArgumentError if self.class != union.class
(@addr - union.instance_variable_get(:@addr)) / @sizeof
end
# @param sizeof [Integer]
# @param members [Hash{ Symbol => RubyVM::RJIT::CType::* }]
def self.define(sizeof, members)
Class.new(self) do
# Return the size of this type
define_singleton_method(:sizeof) { sizeof }
# Part of Struct's offsetof implementation
define_singleton_method(:offsetof) do |field, *fields|
member = members.fetch(field)
offset = 0
unless fields.empty?
offset += member.offsetof(*fields)
end
offset
end
define_method(:initialize) do |addr|
super(addr, sizeof, members)
end
members.each do |member, type|
# Intelligent API that does automatic dereference
define_method(member) do
value = type.new(@addr)
if value.respond_to?(:*)
value = value.*
end
value
end
end
end
end
end
class Immediate
# @param addr [Integer]
# @param size [Integer]
# @param pack [String]
def initialize(addr, size, pack)
@addr = addr
@size = size
@pack = pack
end
# Get a raw address
def to_i
@addr
end
# Move addr to addess this pointer like an array
def +(index)
Immediate.new(@addr + index * @size, @size, @pack)
end
# Dereference
def *
self[0]
end
# Array access
def [](index)
return nil if @addr == 0
Fiddle::Pointer.new(@addr + index * @size)[0, @size].unpack1(@pack)
end
# Array set
def []=(index, value)
Fiddle::Pointer.new(@addr + index * @size)[0, @size] = [value].pack(@pack)
end
# Serialized address for generated code. Used for embedding things like body->iseq_encoded.
def to_s
"0x#{Integer(@addr).to_s(16)}"
end
# @param fiddle_type [Integer] Fiddle::TYPE_*
def self.define(fiddle_type)
size = Fiddle::PackInfo::SIZE_MAP.fetch(fiddle_type)
pack = Fiddle::PackInfo::PACK_MAP.fetch(fiddle_type)
Class.new(self) do
define_method(:initialize) do |addr|
super(addr, size, pack)
end
define_singleton_method(:size) do
size
end
# Type-level []=: Used by struct fields
define_singleton_method(:[]=) do |addr, value|
Fiddle::Pointer.new(addr)[0, size] = [value].pack(pack)
end
end
end
end
# -Fiddle::TYPE_CHAR Immediate with special handling of true/false
class Bool < Immediate.define(-Fiddle::TYPE_CHAR)
# Dereference
def *
return nil if @addr == 0
super != 0
end
def self.[]=(addr, value)
super(addr, value ? 1 : 0)
end
end
# Basically Immediate but without #* to skip auto-dereference of structs.
class Array
attr_reader :type
# @param addr [Integer]
# @param type [Class] RubyVM::RJIT::CType::*
def initialize(addr, type)
@addr = addr
@type = type
end
# Array access
def [](index)
@type.new(@addr)[index]
end
# Array set
# @param index [Integer]
# @param value [Integer, RubyVM::RJIT::CPointer::Struct] an address itself or an object that return an address with to_i
def []=(index, value)
@type.new(@addr)[index] = value
end
private
def self.define(block)
Class.new(self) do
define_method(:initialize) do |addr|
super(addr, block.call)
end
end
end
end
class Pointer
attr_reader :type
# @param addr [Integer]
# @param type [Class] RubyVM::RJIT::CType::*
def initialize(addr, type)
@addr = addr
@type = type
end
# Move addr to addess this pointer like an array
def +(index)
raise ArgumentError unless index.is_a?(Integer)
Pointer.new(@addr + index * Fiddle::SIZEOF_VOIDP, @type)
end
# Dereference
def *
return nil if dest_addr == 0
@type.new(dest_addr)
end
# Array access
def [](index)
(self + index).*
end
# Array set
# @param index [Integer]
# @param value [Integer, RubyVM::RJIT::CPointer::Struct] an address itself or an object that return an address with to_i
def []=(index, value)
Fiddle::Pointer.new(@addr + index * Fiddle::SIZEOF_VOIDP)[0, Fiddle::SIZEOF_VOIDP] =
[value.to_i].pack(Fiddle::PackInfo::PACK_MAP[Fiddle::TYPE_VOIDP])
end
# Get a raw address
def to_i
@addr
end
private
def dest_addr
Fiddle::Pointer.new(@addr)[0, Fiddle::SIZEOF_VOIDP].unpack1(Fiddle::PackInfo::PACK_MAP[Fiddle::TYPE_VOIDP])
end
def self.define(block)
Class.new(self) do
define_method(:initialize) do |addr|
super(addr, block.call)
end
# Type-level []=: Used by struct fields
# @param addr [Integer]
# @param value [Integer, RubyVM::RJIT::CPointer::Struct] an address itself, or an object that return an address with to_i
define_singleton_method(:[]=) do |addr, value|
value = value.to_i
Fiddle::Pointer.new(addr)[0, Fiddle::SIZEOF_VOIDP] = [value].pack(Fiddle::PackInfo::PACK_MAP[Fiddle::TYPE_VOIDP])
end
end
end
end
class BitField
# @param addr [Integer]
# @param width [Integer]
# @param offset [Integer]
def initialize(addr, width, offset)
@addr = addr
@width = width
@offset = offset
end
# Dereference
def *
byte = Fiddle::Pointer.new(@addr)[0, Fiddle::SIZEOF_CHAR].unpack('c').first
if @width == 1
bit = (1 & (byte >> @offset))
bit == 1
elsif @width <= 8 && @offset == 0
bitmask = @width.times.map { |i| 1 << i }.sum
byte & bitmask
else
raise NotImplementedError.new("not-implemented bit field access: width=#{@width} offset=#{@offset}")
end
end
# @param width [Integer]
# @param offset [Integer]
def self.define(width, offset)
Class.new(self) do
define_method(:initialize) do |addr|
super(addr, width, offset)
end
end
end
end
# Give a name to a dynamic CPointer class to see it on inspect
def self.with_class_name(prefix, name, cache: false, &block)
return block.call if !name.nil? && name.empty?
# Use a cached result only if cache: true
class_name = "#{prefix}_#{name}"
klass =
if cache && self.const_defined?(class_name)
self.const_get(class_name)
else
block.call
end
# Give it a name unless it's already defined
unless self.const_defined?(class_name)
self.const_set(class_name, klass)
end
klass
end
end
end