Class: Indis::MachO::Symbol

Inherits:
Object
  • Object
show all
Defined in:
lib/indis-macho/symbol.rb

Constant Summary collapse

STAB_MASK = 
0xe0
PEXT_MASK = 
0x10
TYPE_MASK = 
0x0e
EXT_MASK = 
0x01
TYPE = 
{
  0x0 => :UNDEF,
  0x2 => :ABS,
  0xe => :SECT,
  0xc => :PBUD,
  0xa => :INDR,
}
STAB = 
{
  0x20 => :N_GSYM,    # global symbol
  0x22 => :N_FNAME,   # procedure name (f77 kludge)
  0x24 => :N_FUN,     # procedure name
  0x26 => :N_STSYM,   # static symbol
  0x28 => :N_LCSYM,   # .lcomm symbol
  0x2e => :N_BNSYM,   # begin nsect symbol
  0x3c => :N_OPT,     # emitted with gcc2_compiled and in gcc source
  0x40 => :N_RSYM,    # register symbol
  0x44 => :N_SLINE,   # src line
  0x4e => :N_ENSYM,   # end nsect symbol
  0x60 => :N_SSYM,    # structure elt
  0x64 => :N_SO,      # source file name
  0x66 => :N_OSO,     # object file name
  0x80 => :N_LSYM,    # local symbol
  0x82 => :N_BINCL,   # include file beginning
  0x84 => :N_SOL,     # #included file name
  0x86 => :N_PARAMS,  # compiler parameters
  0x88 => :N_VERSION, # compiler version
  0x8A => :N_OLEVEL,  # compiler -O level
  0xa0 => :N_PSYM,    # parameter
  0xa2 => :N_EINCL,   # include file end
  0xa4 => :N_ENTRY,   # alternate entry
  0xc0 => :N_LBRAC,   # left bracket
  0xc2 => :N_EXCL,    # deleted include file
  0xe0 => :N_RBRAC,   # right bracket
  0xe2 => :N_BCOMM,   # begin common
  0xe4 => :N_ECOMM,   # end common
  0xe8 => :N_ECOML,   # end common (local name)
  0xfe => :N_LENG,    # second stab entry with length information
}
REFERENCE_TYPE_MASK =

second stab entry with length information

0xf
DESC_REFERENCE = 
{
  0x0 => :REFERENCE_FLAG_UNDEFINED_NON_LAZY,
  0x1 => :REFERENCE_FLAG_UNDEFINED_LAZY,
  0x2 => :REFERENCE_FLAG_DEFINED,
  0x3 => :REFERENCE_FLAG_PRIVATE_DEFINED,
  0x4 => :REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY,
  0x5 => :REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY,
}
DESC_ADDITIONAL = 
{
  0x08 => :N_ARM_THUMB_DEF,
  0x10 => :REFERENCED_DYNAMICALLY,
  0x20 => :N_DESC_DISCARDED_OR_N_NO_DEAD_STRIP, # TODO: resolve mach file type
  0x40 => :N_WEAK_REF,
  0x80 => :N_WEAK_DEF,
}
LIBRARY_ORDINAL = 
{
  0x0  => :SELF_LIBRARY_ORDINAL,
  0xfe => :DYNAMIC_LOOKUP_ORDINAL,
  0xff => :EXECUTABLE_ORDINAL,
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(payload, strtab) ⇒ Symbol

Returns a new instance of Symbol.



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# File 'lib/indis-macho/symbol.rb', line 89

def initialize(payload, strtab)
  name_idx, @type_val, @sect, @desc_val, @value = payload.read(12).unpack('VCCSV')
  if name_idx == 0
    @name = ''
  else
    @name = strtab[name_idx..-1].split("\0", 2)[0]
  end
  
  # if stab?
  #   puts ".stabs \"#{@name}\", #{STAB[@type_val]}, #{@sect}, #{self.desc}, #{@value}"
  # else
  #   puts "SYM \"#{@name}\", #{TYPE[@type_val & TYPE_MASK]}, #{@sect}, #{self.desc}, #{@value}"
  # end
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/indis-macho/symbol.rb', line 87

def name
  @name
end

#sect ⇒ Object (readonly)

Returns the value of attribute sect.



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# File 'lib/indis-macho/symbol.rb', line 87

def sect
  @sect
end

#value ⇒ Object (readonly)

Returns the value of attribute value.



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# File 'lib/indis-macho/symbol.rb', line 87

def value
  @value
end

Instance Method Details

#desc ⇒ Object 



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# File 'lib/indis-macho/symbol.rb', line 132

def desc
  d = [DESC_REFERENCE[@desc_val & REFERENCE_TYPE_MASK]]
  DESC_ADDITIONAL.each_pair do |k, v|
    d << v if @desc_val & k == k
  end
  d
end

#extern? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/indis-macho/symbol.rb', line 128

def extern?
  @type_val & EXT_MASK == EXT_MASK
end

#private_extern? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/indis-macho/symbol.rb', line 124

def private_extern?
  @type_val & PEXT_MASK == PEXT_MASK
end

#stab ⇒ Object 



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# File 'lib/indis-macho/symbol.rb', line 116

def stab
  if stab?
    STAB[@type_val]
  else
    nil
  end
end

#stab? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/indis-macho/symbol.rb', line 112

def stab?
  @type_val & STAB_MASK != 0
end

#twolevel_library_ordinal ⇒ Object 



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# File 'lib/indis-macho/symbol.rb', line 140

def twolevel_library_ordinal
  lo = (@desc_val >> 8) & 0xff
  LIBRARY_ORDINAL[lo] || lo
end

#type ⇒ Object 



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# File 'lib/indis-macho/symbol.rb', line 104

def type
  if stab?
    STAB[@type_val]
  else
    TYPE[@type_val & TYPE_MASK]
  end
end