Class: ElfUtils::Section::DebugInfo::Die::Base

Inherits:
Object
  • Object
show all
Includes:
CTypes::Helpers
Defined in:
lib/elf_utils/section/debug_info/die/base.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(cu:, offset:, attrs:, has_children:) ⇒ Base

Returns a new instance of Base.



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 5

def initialize(cu:, offset:, attrs:, has_children:)
  @cu = cu
  @offset = offset
  @attrs = attrs
  @children = [] if has_children
end

Instance Attribute Details

#cu ⇒ Object (readonly)

Returns the value of attribute cu.



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 11

def cu
  @cu
end

#offset ⇒ Object (readonly)

Returns the value of attribute offset.



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 11

def offset
  @offset
end

#tag ⇒ Object (readonly)

Returns the value of attribute tag.



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 11

def tag
  @tag
end

Instance Method Details

#<<(child) ⇒ Object

Raises:



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 13

def <<(child)
  raise Error, "This DIE cannot have children" unless @children
  @children << child
end

#children ⇒ Object 



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 22

def children
  # to make it easier to walk a tree of DIEs, we're going to return an
  # empty array for DIEs that don't have children
  @children || []
end

#children? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 18

def children?
  !!@children
end

#ctype ⇒ Object 



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 45

def ctype
  return unless type?
  return @ctype if @ctype

  name, type = case tag
  when :base_type
    unsigned = @attrs[:encoding].to_s.include?("unsigned")
    type = case @attrs[:byte_size]
    when 1
      unsigned ? uint8 : int8
    when 2
      unsigned ? uint16 : int16
    when 4
      unsigned ? uint32 : int32
    when 8
      unsigned ? uint64 : int64
    else
      raise "unsupported base_type size: %p" % die
    end
    [@attrs[:name].deref, type.with_endian(@cu.file.endian)]
  when :volatile_type
    name, type = @attrs[:type].deref.ctype
    ["volatile #{name}", type]
  when :typedef
    _, type = @attrs[:type].deref.ctype
    [@attrs[:name].deref, type]
  when :array_type
    name, inner_type = @attrs[:type].deref.ctype

    subrange = children.find { |c| c.tag == :subrange_type }
    size = if subrange.has_attr?(:count)
      subrange.count
    elsif subrange.has_attr?(:upper_bound)
      subrange.upper_bound
    end

    # XXX need flexible array member test

    # if we have a signed char array, we'll use that
    if inner_type.is_a?(CTypes::Int) &&
        inner_type.size == 1 &&
        inner_type.signed?
      ["#{name}[#{size}]", string(size)]
    else
      ["#{name}[#{size}]", array(inner_type, size)]
    end
  when :pointer_type
    type = @attrs[:type].deref
    name, = type.ctype
    [(type.tag == :pointer_type) ? "#{name}*" : "#{name} *", @cu.addr_type]
  when :structure_type
    fields, = @children.inject([{}, 0]) do |(o, offset), child|
      next [o, offset] unless child.tag == :member

      pad = child.data_member_location - offset
      o[:"__pad_#{offset}"] = string(pad, trim: false) if pad != 0

      _, type = child.type.deref.ctype
      o[child.name.deref.to_sym] = type
      [o, child.data_member_location + type.size]
    end

    name = @attrs[:name]&.deref || ("anon_%x" % offset)

    ["struct #{name}", struct(**fields)]
  when :union_type
    layout = @children.each_with_object({}) do |child, o|
      next o unless child.tag == :member

      _, type = child.type.deref.ctype
      o[child.name.deref.to_sym] = type
    end

    name = @attrs[:name]&.deref || ("anon_%x" % offset)

    ["union #{name}", union(**layout)]
  when :subrange_type, :subroutine_type
    return
  else
    raise Error, "unsupported DIE: %p" % [die]
  end

  @ctype = [name, type]
end

#has_attr?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 37

def has_attr?(key)
  @attrs.has_key?(key)
end

#inspect ⇒ Object 



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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 28

def inspect
  buf = "<%p\n    0x%08x: DW_TAG_%s (children=%p)\n" %
    [self.class, @offset, tag, @children ? @children.size : false]
  @attrs.each do |name, value|
    buf << "            DW_AT_%-15s %p\n" % [name, value]
  end
  buf.chomp! << ">"
end

#type? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/elf_utils/section/debug_info/die/base.rb', line 41

def type?
  tag == :typedef || tag.to_s.end_with?("_type")
end