Module: Fiddle::Importer

Extended by:
Importer
Includes:
Fiddle, CParser
Included in:
Importer
Defined in:
lib/fiddle/import.rb

Overview

A DSL that provides the means to dynamically load libraries and build modules around them including calling extern functions within the C library that has been loaded.

Example

require 'fiddle'
require 'fiddle/import'

module LibSum
	extend Fiddle::Importer
	dlload './libsum.so'
	extern 'double sum(double*, int)'
	extern 'double split(double)'
end

Constant Summary

Constants included from Fiddle

ALIGN_CHAR, ALIGN_DOUBLE, ALIGN_FLOAT, ALIGN_INT, ALIGN_INTPTR_T, ALIGN_LONG, ALIGN_LONG_LONG, ALIGN_PTRDIFF_T, ALIGN_SHORT, ALIGN_SIZE_T, ALIGN_SSIZE_T, ALIGN_UINTPTR_T, ALIGN_VOIDP, BUILD_RUBY_PLATFORM, NULL, RTLD_GLOBAL, RTLD_LAZY, RTLD_NOW, RUBY_FREE, SIZEOF_CHAR, SIZEOF_DOUBLE, SIZEOF_FLOAT, SIZEOF_INT, SIZEOF_INTPTR_T, SIZEOF_LONG, SIZEOF_LONG_LONG, SIZEOF_PTRDIFF_T, SIZEOF_SHORT, SIZEOF_SIZE_T, SIZEOF_SSIZE_T, SIZEOF_UINTPTR_T, SIZEOF_VOIDP, TYPE_CHAR, TYPE_DOUBLE, TYPE_FLOAT, TYPE_INT, TYPE_INTPTR_T, TYPE_LONG, TYPE_LONG_LONG, TYPE_PTRDIFF_T, TYPE_SHORT, TYPE_SIZE_T, TYPE_SSIZE_T, TYPE_UINTPTR_T, TYPE_VOID, TYPE_VOIDP, WINDOWS

Instance Method Summary collapse

Methods included from CParser

#parse_ctype, #parse_signature, #parse_struct_signature

Methods included from Fiddle

dlopen, dlunwrap, dlwrap, free, last_error, last_error=, malloc, realloc, win32_last_error, win32_last_error=

Instance Method Details

#[](name) ⇒ Object

Returns the function mapped to name, that was created by either Fiddle::Importer.extern or Fiddle::Importer.bind



237
238
239
 
# File 'lib/fiddle/import.rb', line 237

def [](name)
  @func_map[name]
end

#bind(signature, *opts, &blk) ⇒ Object

Creates a global method from the given C signature using the given opts as bind parameters with the given block.



193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
 
# File 'lib/fiddle/import.rb', line 193

def bind(signature, *opts, &blk)
  name, ctype, argtype = parse_signature(signature, type_alias)
  h = parse_bind_options(opts)
  case h[:callback_type]
  when :bind, nil
    f = bind_function(name, ctype, argtype, h[:call_type], &blk)
  else
    raise(RuntimeError, "unknown callback type: #{h[:callback_type]}")
  end
  @func_map[name] = f
  #define_method(name){|*args,&block| f.call(*args,&block)}
  begin
    /^(.+?):(\d+)/ =~ caller.first
    file, line = $1, $2.to_i
  rescue
    file, line = __FILE__, __LINE__+3
  end
  module_eval(<<-EOS, file, line)
    def #{name}(*args,&block)
      @func_map['#{name}'].call(*args,&block)
    end
  EOS
  module_function(name)
  f
end

#bind_function(name, ctype, argtype, call_type = nil, &block) ⇒ Object

Returns a new closure wrapper for the name function.

  • ctype is the return type of the function

  • argtype is an Array of arguments, passed to the callback function

  • call_type is the abi of the closure

  • block is passed to the callback

See Fiddle::Closure



313
314
315
316
317
318
319
320
 
# File 'lib/fiddle/import.rb', line 313

def bind_function(name, ctype, argtype, call_type = nil, &block)
  abi = CALL_TYPE_TO_ABI[call_type]
  closure = Class.new(Fiddle::Closure) {
    define_method(:call, block)
  }.new(ctype, argtype, abi)

  Function.new(closure, argtype, ctype, abi, name: name)
end

#create_value(ty, val = nil) ⇒ Object Also known as: value

Creates a class to wrap the C struct with the value ty

See also Fiddle::Importer.struct



244
245
246
247
248
249
250
251
 
# File 'lib/fiddle/import.rb', line 244

def create_value(ty, val=nil)
  s = struct([ty + " value"])
  ptr = s.malloc()
  if( val )
    ptr.value = val
  end
  return ptr
end

#dlload(*libs) ⇒ Object

Creates an array of handlers for the given libs, can be an instance of Fiddle::Handle, Fiddle::Importer, or will create a new instance of Fiddle::Handle using Fiddle.dlopen

Raises a DLError if the library cannot be loaded.

See Fiddle.dlopen



76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
 
# File 'lib/fiddle/import.rb', line 76

def dlload(*libs)
  handles = libs.collect{|lib|
    case lib
    when nil
      nil
    when Handle
      lib
    when Importer
      lib.handlers
    else
      begin
        Fiddle.dlopen(lib)
      rescue DLError
        raise(DLError, "can't load #{lib}")
      end
    end
  }.flatten()
  @handler = CompositeHandler.new(handles)
  @func_map = {}
  @type_alias = {}
end

#extern(signature, *opts) ⇒ Object

Creates a global method from the given C signature.



169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
 
# File 'lib/fiddle/import.rb', line 169

def extern(signature, *opts)
  symname, ctype, argtype = parse_signature(signature, type_alias)
  opt = parse_bind_options(opts)
  f = import_function(symname, ctype, argtype, opt[:call_type])
  name = symname.gsub(/@.+/,'')
  @func_map[name] = f
  # define_method(name){|*args,&block| f.call(*args,&block)}
  begin
    /^(.+?):(\d+)/ =~ caller.first
    file, line = $1, $2.to_i
  rescue
    file, line = __FILE__, __LINE__+3
  end
  module_eval(<<-EOS, file, line)
    def #{name}(*args, &block)
      @func_map['#{name}'].call(*args,&block)
    end
  EOS
  module_function(name)
  f
end

#handler ⇒ Object

The Fiddle::CompositeHandler instance

Will raise an error if no handlers are open.



266
267
268
 
# File 'lib/fiddle/import.rb', line 266

def handler
  (@handler ||= nil) or raise "call dlload before importing symbols and functions"
end

#import_function(name, ctype, argtype, call_type = nil) ⇒ Object

Returns a new Fiddle::Function instance at the memory address of the given name function.

Raises a DLError if the name doesn’t exist.

  • argtype is an Array of arguments, passed to the name function.

  • ctype is the return type of the function

  • call_type is the ABI of the function

See also Fiddle:Function.new

See Fiddle::CompositeHandler.sym and Fiddle::Handler.sym



296
297
298
299
300
301
302
303
 
# File 'lib/fiddle/import.rb', line 296

def import_function(name, ctype, argtype, call_type = nil)
  addr = handler.sym(name)
  if( !addr )
    raise(DLError, "cannot find the function: #{name}()")
  end
  Function.new(addr, argtype, ctype, CALL_TYPE_TO_ABI[call_type],
               name: name)
end

#import_symbol(name) ⇒ Object

Returns a new Fiddle::Pointer instance at the memory address of the given name symbol.

Raises a DLError if the name doesn’t exist.

See Fiddle::CompositeHandler.sym and Fiddle::Handle.sym



276
277
278
279
280
281
282
 
# File 'lib/fiddle/import.rb', line 276

def import_symbol(name)
  addr = handler.sym(name)
  if( !addr )
    raise(DLError, "cannot find the symbol: #{name}")
  end
  Pointer.new(addr)
end

#import_value(ty, addr) ⇒ Object

Returns a new instance of the C struct with the value ty at the addr address.



256
257
258
259
260
 
# File 'lib/fiddle/import.rb', line 256

def import_value(ty, addr)
  s = struct([ty + " value"])
  ptr = s.new(addr)
  return ptr
end

#sizeof(ty) ⇒ Object

Returns the sizeof ty, using Fiddle::Importer.parse_ctype to determine the C type and the appropriate Fiddle constant.



105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
 
# File 'lib/fiddle/import.rb', line 105

def sizeof(ty)
  case ty
  when String
    ty = parse_ctype(ty, type_alias).abs()
    case ty
    when TYPE_CHAR
      return SIZEOF_CHAR
    when TYPE_SHORT
      return SIZEOF_SHORT
    when TYPE_INT
      return SIZEOF_INT
    when TYPE_LONG
      return SIZEOF_LONG
    when TYPE_FLOAT
      return SIZEOF_FLOAT
    when TYPE_DOUBLE
      return SIZEOF_DOUBLE
    when TYPE_VOIDP
      return SIZEOF_VOIDP
    else
      if defined?(TYPE_LONG_LONG) and
        ty == TYPE_LONG_LONG
        return SIZEOF_LONG_LONG
      else
        raise(DLError, "unknown type: #{ty}")
      end
    end
  when Class
    if( ty.instance_methods().include?(:to_ptr) )
      return ty.size()
    end
  end
  return Pointer[ty].size()
end

#struct(signature) ⇒ Object

Creates a class to wrap the C struct described by signature.

MyStruct = struct ['int i', 'char c']



222
223
224
225
 
# File 'lib/fiddle/import.rb', line 222

def struct(signature)
  tys, mems = parse_struct_signature(signature, type_alias)
  Fiddle::CStructBuilder.create(CStruct, tys, mems)
end

#typealias(alias_type, orig_type) ⇒ Object

Sets the type alias for alias_type as orig_type



99
100
101
 
# File 'lib/fiddle/import.rb', line 99

def typealias(alias_type, orig_type)
  @type_alias[alias_type] = orig_type
end

#union(signature) ⇒ Object

Creates a class to wrap the C union described by signature.

MyUnion = union ['int i', 'char c']



230
231
232
233
 
# File 'lib/fiddle/import.rb', line 230

def union(signature)
  tys, mems = parse_struct_signature(signature, type_alias)
  Fiddle::CStructBuilder.create(CUnion, tys, mems)
end