lib/ffi/types_generator.rb

   1 require 'tempfile'
   2
   3 module FFI
   4   class TypesGenerator
   5
   6     ##
   7     # Maps different C types to the C type representations we use
   8
   9     TYPE_MAP = {
  10                "char" => :char,
  11         "signed char" => :char,
  12       "__signed char" => :char,
  13       "unsigned char" => :uchar,
  14
  15                "short"     => :short,
  16         "signed short"     => :short,
  17         "signed short int" => :short,
  18       "unsigned short"     => :ushort,
  19       "unsigned short int" => :ushort,
  20
  21                "int" => :int,
  22         "signed int" => :int,
  23       "unsigned int" => :uint,
  24
  25                "long" => :long,
  26                "long int" => :long,
  27         "signed long" => :long,
  28         "signed long int" => :long,
  29       "unsigned long" => :ulong,
  30       "unsigned long int" => :ulong,
  31       "long unsigned int" => :ulong,
  32
  33                "long long"     => :long_long,
  34                "long long int" => :long_long,
  35         "signed long long"     => :long_long,
  36         "signed long long int" => :long_long,
  37       "unsigned long long"     => :ulong_long,
  38       "unsigned long long int" => :ulong_long,
  39
  40       "char *" => :string,
  41       "void *" => :pointer,
  42     }
  43
  44     def self.generate
  45       typedefs = nil
  46       Tempfile.open 'ffi_types_generator' do |io|
  47         io.puts <<-C
  48 #include <sys/types.h>
  49 #include <sys/socket.h>
  50 #include <sys/resource.h>
  51         C
  52
  53         io.close
  54
  55         typedefs = `cpp -D_DARWIN_USE_64_BIT_INODE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 #{io.path}`
  56       end
  57
  58       code = ""
  59
  60       typedefs.each do |type|
  61         # We only care about single line typedef
  62         next unless type =~ /typedef/
  63         # Ignore unions or structs
  64         next if type =~ /union|struct/
  65
  66         # strip off the starting typedef and ending ;
  67         type.gsub!(/^(.*typedef\s*)/, "")
  68         type.gsub!(/\s*;\s*$/, "")
  69
  70         parts = type.split(/\s+/)
  71         def_type   = parts.join(" ")
  72
  73         # GCC does mapping with __attribute__ stuf, also see
  74         # http://hal.cs.berkeley.edu/cil/cil016.html section 16.2.7.  Problem
  75         # with this is that the __attribute__ stuff can either occur before or
  76         # after the new type that is defined...
  77         if type =~ /__attribute__/
  78           if parts.last =~ /__QI__|__HI__|__SI__|__DI__|__word__/
  79
  80             # In this case, the new type is BEFORE __attribute__ we need to
  81             # find the final_type as the type before the part that starts with
  82             # __attribute__
  83             final_type = ""
  84             parts.each do |p|
  85               break if p =~ /__attribute__/
  86               final_type = p
  87             end
  88           else
  89             final_type = parts.pop
  90           end
  91
  92           def_type = case type
  93                      when /__QI__/   then "char"
  94                      when /__HI__/   then "short"
  95                      when /__SI__/   then "int"
  96                      when /__DI__/   then "long long"
  97                      when /__word__/ then "long"
  98                      else                 "int"
  99                      end
 100
 101           def_type = "unsigned #{def_type}" if type =~ /unsigned/
 102         else
 103           final_type = parts.pop
 104           def_type   = parts.join(" ")
 105         end
 106
 107         if type = TYPE_MAP[def_type]
 108           code << "rbx.platform.typedef.#{final_type} = #{type}\n"
 109           TYPE_MAP[final_type] = TYPE_MAP[def_type]
 110         else
 111           # Fallback to an ordinary pointer if we don't know the type
 112           if def_type =~ /\*/
 113             code << "rbx.platform.typedef.#{final_type} = pointer\n"
 114             TYPE_MAP[final_type] = :pointer
 115           end
 116         end
 117       end
 118
 119       code
 120     end
 121
 122   end
 123 end
 124