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


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# 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.


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# 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("def \#{name}(*args,&block)\[email protected]_map['\#{name}'].call(*args,&block)\nend\n", file, line)
  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


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# 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


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# 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


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# 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.


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# 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("def \#{name}(*args, &block)\[email protected]_map['\#{name}'].call(*args,&block)\nend\n", file, line)
  module_function(name)
  f
end

#handlerObject

The Fiddle::CompositeHandler instance

Will raise an error if no handlers are open.


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# 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


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# 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


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# 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.


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# 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.


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# 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']

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# 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


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# 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']

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# 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