Class: Dub::Lua::FunctionGen

Inherits:
Generator show all
Defined in:
lib/dub/lua/function_gen.rb

Constant Summary collapse

NUMBER_TYPES = 
[
  'float',
  'double',
  'time_t',
]
INT_TYPES = 
[
  'int',
  'size_t',
  'unsigned int',
  'uint',
  'uchar',
  'char',
]
BOOL_TYPES = 
[
  'bool',
]
DEFAULT_CUSTOM_TYPES = 
[
  [/lua_State /, Proc.new do |type_def, arg, stack_pos|
    if type_def =~ /lua_State\s*\*\s*L/
      ""
    else
      "#{type_def} = L;"
    end
  end]
]

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Generator

#comment

Constructor Details

#initialize ⇒ FunctionGen

Returns a new instance of FunctionGen.



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# File 'lib/dub/lua/function_gen.rb', line 40

def initialize
  load_erb
  @custom_types = DEFAULT_CUSTOM_TYPES.dup
end

Instance Attribute Details

#klass ⇒ Object

klass is used when parsing members from the superclasses.



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# File 'lib/dub/lua/function_gen.rb', line 9

def klass
  @klass
end

#template_path ⇒ Object

klass is used when parsing members from the superclasses.



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# File 'lib/dub/lua/function_gen.rb', line 9

def template_path
  @template_path
end

Instance Method Details

#body(func, check_prefix) ⇒ Object

The check_prefix parameter chooses between dubL_check and luaL_check depending on exceptions that can be thrown.



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# File 'lib/dub/lua/function_gen.rb', line 136

def body(func, check_prefix)
  res = []
  delta_top = 0
  if func.member_method? && !func.constructor? && !func.static?
    # Force @klass when serializing members from superclass.
    klass = @klass || func.parent
    res << "#{klass.name} *#{SELF} = *((#{klass.name}**)#{check_prefix}L_checksdata(L, 1, #{klass.id_name.inspect}));"
    if func.member_method? && func.klass.custom_destructor?
      # protect calls
      if check_prefix == 'dub'
        # we cannot use luaL_error
        res << "if (!#{SELF}) throw dub::Exception(\"Using deleted #{klass.id_name} in #{func.name}\");"
      else
        res << "if (!#{SELF}) return luaL_error(L, \"Using deleted #{klass.id_name} in #{func.name}\");"
      end
    end
    delta_top = 1
  end
  
  custom_body = func.custom_body('lua')

  if_indent = 0
  if custom_body && func.has_default_arguments?
    # we do not prepare arguments
  else
    if func.has_default_arguments?
      res << "int top__ = lua_gettop(L);"
      if return_value = func.return_value
        res << "#{return_value.create_type} retval__;"
      end
    end
    func.arguments.each_with_index do |arg, i|
      if arg.has_default?
        res << indent("if (top__ < #{i+1+delta_top}) {",     if_indent)
        res << indent("  #{call_string(func, i)}", if_indent)
        res << indent("} else {", if_indent)
        if_indent += 2
      end
      res << indent(get_arg(arg, i + 1 + delta_top, check_prefix), if_indent)
    end
  end
  if custom_body
    res << indent(custom_body, if_indent)
  else
    res << indent(call_string(func, func.arguments.count), if_indent)
  end
  while if_indent > 0
    if_indent -= 2
    res << indent("}", if_indent)
  end

  unless custom_body
    res << return_value(func)
  end
  res.join("\n")
end

#call_string(func, upto_arg = nil) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 203

def call_string(func, upto_arg = nil)
  upto_arg ||= func.arguments.count
  if upto_arg == 0
    call_string = "#{func.call_name}();"
  else
    call_string = "#{func.call_name}(#{func.arguments[0..(upto_arg-1)].map{|arg| arg.in_call_type}.join(', ')});"
  end

  if func.constructor?
    call_string = "new #{call_string}"
  elsif func.member_method? && !func.static?
    call_string = "#{SELF}->#{call_string}"
  end


  if return_value = func.return_value
    if func.has_default_arguments?
      "retval__ = #{call_string}"
    else
      "#{return_value.create_type} retval__ = #{call_string}"
    end
  else
    call_string
  end
end

#chooser_body(group = @group) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 77

def chooser_body(group = @group)
  if group.first.member_method? && !group.first.constructor?
    delta_depth = 1
  else
    delta_depth = 0
  end
  decision_tree = Argument.decision_tree(group.members)
  res = []
  res << "int type__ = lua_type(L, #{1 + delta_depth});"
  if flatten_hash(decision_tree).include?(nil)
    res << "int top__  = lua_gettop(L);"
  end
  res << switch(decision_tree, delta_depth + 1, true)
  res.join("\n")
end

#ctor_with_lua_init?(func) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dub/lua/function_gen.rb', line 318

def ctor_with_lua_init?(func)
  # If the class inherits from LuaObject, we need to use
  # s->lua_init(L); instead of pushclass.
  if func.constructor?
    func.klass.ancestors.detect{|a| a =~ /LuaObject/}
  else
    false
  end
end

#custom_type(regexp, &block) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 50

def custom_type(regexp, &block)
  @custom_types << [regexp, block]
end

#flatten_hash(hash) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 301

def flatten_hash(hash)
  list = []
  hash.each do |k, v|
    if v.kind_of?(Hash)
      list << [k, flatten_hash(v)]
    else
      list << [k, v]
    end
  end
  list.flatten
end

#function(function) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 64

def function(function)
  @function = function
  @function_template.result(binding)
end

#function_generator ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 69

def function_generator
  self
end

#get_arg(arg, stack_pos, check_prefix) ⇒ Object

Get argument and verify type // luaL_argcheck could be better to report errors like “expected Mat” the check_prefix chooses between ‘luaL_check…’ and ‘dubL_check’ methods depending on C++ exceptions raised by the function.



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# File 'lib/dub/lua/function_gen.rb', line 270

def get_arg(arg, stack_pos, check_prefix)
  type_def = "#{arg.create_type}#{arg.name}#{arg.array_suffix}"
  if custom_type = @custom_types.detect {|reg,proc| type_def =~ reg}
    custom_type[1].call(type_def, arg, stack_pos)
  elsif arg.is_native?
    if arg.is_pointer?
      if arg.type == 'char'
        type_def = "const #{type_def}" unless arg.is_const?
        "#{type_def} = #{check_prefix}L_checkstring(L, #{stack_pos});"
      else
        # retrieve by using a table accessor
        # TODO: we should have a hint on required sizes !
        "\nDubArgPointer<#{arg.type}> ptr_#{arg.name};\n" +
        "#{type_def} = ptr_#{arg.name}(L, #{stack_pos});"
      end
    else
      if NUMBER_TYPES.include?(arg.type)
        "#{type_def} = #{check_prefix}L_checknumber(L, #{stack_pos});"
      elsif BOOL_TYPES.include?(arg.type)
        "#{type_def} = lua_toboolean(L, #{stack_pos});"
      elsif INT_TYPES.include?(arg.type)
        "#{type_def} = #{check_prefix}L_checkint(L, #{stack_pos});"
      else
        raise "Unsuported type: #{arg.type}"
      end
    end
  else
    "#{type_def} = *((#{arg.create_type}*)#{check_prefix}L_checksdata(L, #{stack_pos}, #{arg.id_name.inspect}));"
  end
end

#group(group) ⇒ Object

Produce bindings for a group of overloaded functions



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# File 'lib/dub/lua/function_gen.rb', line 55

def group(group)
  @group = group
  if @group.members
    @group_template.result(binding)
  else
    ''
  end
end

#load_erb ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 313

def load_erb
  @function_template = ::ERB.new(File.read(@template_path ||File.join(File.dirname(__FILE__), 'function.cpp.erb')), nil, '%<>-')
  @group_template    = ::ERB.new(File.read(File.join(File.dirname(__FILE__), 'group.cpp.erb')))
end

#method_call(func) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 199

def method_call(func)
  "return #{method_name(func)}(L);"
end

#method_name(func, overloaded_index = nil) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 193

def method_name(func, overloaded_index = nil)
  overloaded_index ||= func.overloaded_index
  overloaded_index = '' if overloaded_index == 0
  "#{func.prefix}_#{func.name}#{overloaded_index}"
end

#namespace_generator ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 73

def namespace_generator
  Dub::Lua.namespace_generator
end

#return_value(func) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 229

def return_value(func)
  res = []
  if return_value = func.return_value
    if return_value.create_type == 'LuaStackSize '
      return "return retval__;"
    end
    case Argument.type_group(return_value)
    when :number
      res << "lua_pushnumber(L, retval__);"
    when :boolean
      res << "lua_pushboolean(L, retval__);"
    when :string
      res << "lua_pushstring(L, retval__);"
    else
      pushclass = 'lua_pushclass'
      if func.constructor?
        if ctor_with_lua_init?(func)
          res << "// The class inherits from 'LuaCallback', use lua_init instead of pushclass."
          res << "return retval__->luaInit(L, retval__, \"#{return_value.id_name}\");"
          return res.join("\n")
        elsif func.klass.custom_destructor?
          # Use special pushclass to set userdata
          pushclass = 'lua_pushclass2'
        end
        prefix = func.klass.prefix
      else
        prefix = func.prefix
      end
      res << "#{pushclass}<#{return_value.type}>(L, retval__, \"#{return_value.id_name}\");"
    end
    res << "return 1;"
  else
    res << "return 0;"
  end
  res.join("\n")
end

#signature(func, overloaded_index = nil) ⇒ Object 



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# File 'lib/dub/lua/function_gen.rb', line 130

def signature(func, overloaded_index = nil)
  "static int #{method_name(func, overloaded_index)}(lua_State *L)"
end

#switch(hash_or_function, depth = 1, start = false) ⇒ Object

Create a switch to choose the correct method from argument types (overloaded functions)



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# File 'lib/dub/lua/function_gen.rb', line 94

def switch(hash_or_function, depth = 1, start = false)
  if hash_or_function.kind_of?(Function)
    method_call(hash_or_function)
  else
    res = []
    res << "type__ = lua_type(L, #{depth});" unless start
    else_prefix = ''
    default_sub_group = nil
    hash_or_function.each do |type, sub_group|
      default_sub_group = sub_group
      case type
      when :number
        res << "#{else_prefix}if (type__ == LUA_TNUMBER) {"
      when :string
        res << "#{else_prefix}if (type__ == LUA_TSTRING) {"
      when nil
        res << "#{else_prefix}if (top__ < #{depth}) {"
      else
        res << "#{else_prefix}if (type__ == LUA_TUSERDATA && is_userdata(L, #{depth}, \"#{type}\")) {"
      end

      res << indent(switch(sub_group, depth + 1), 2)

      else_prefix = '} else '
    end

    last = default_sub_group.kind_of?(Hash) ? flatten_hash(default_sub_group).last : default_sub_group

    res << "} else {"
    res << "  // use any to raise errors"
    res << indent(method_call(last), 2)
    res << "}"
    res.join("\n")
  end
end