README

IDLproc

Usage

idlproc language [options] [--] infile [outfile]

language specifies the consumer to use and must be given as first argument. Supported: Pascal.

infile is the first input file.

outfile may be given as a file or directory name. If not given, the current directory is assumed. Giving a file name is only valid if -D was not used.

Options

• -D --dependencies Follow dependencies via #include directives

IDL Dialect

IDL2pas uses a restricted version of MIDL with some features added from XPIDL.

Base Types

The following data types are considered "predefined" and guaranteed to have representations in all consumers. Const-, Reference- or Pointer-ness that is caused by direction modifiers (see Methods below) are not part of the type itself, but instead are generated by the consumer. Interface types are always considered to be passed as instance pointers. Note that this is in contrast to MIDL.

Type Name(s)	C++ Equivalent	ObjFPC Equivalent
Boolean	bool	Boolean
UInt8	unsigned char	Byte
UInt16	unsigned short	Word
UInt32	unsigned long	DWORD
UInt64	unsigned long long	QWORD
Int8	char	Smallint
Int16	short	Shortint
Int32	long	Integer
Int64	long long	Int64
Pointer	void *	Pointer
PtrInt	size_t	PtrInt
PtrUInt	usize_t	PtrUInt
CString	char * (default system codepage)	PAnsiChar
CUTF8String	char * (encoded as UTF8)	PUtf8Char
CWString	wchar_t * (arbitrary encoding)	PUnicodeChar
IID	REFIID	TGUID

Non-Declarative

• #include "file.idl" Read data from file.idl next, return to next line in current file afterwards. Relative paths to the current file are allowed. May occur anywhere a token would be allowed, but must end on a line end.

• Language-specific extensions:

  pascalCopy

  %{[lang]
  (language-specific code here)
  %}

  Emit code verbatim. Optionally give lang on first line to only emit for a specific language consumer. May only occur as top-level declaration.

Declarations

Declarations may optioanlly be wrapped in a MSIDL-Typelib-library definition, but this is not required.

Many Declarations accept Attributes specified before them, they are not spelled in syntax examples here for brevity. Relevant Attributes are given in the Declaration descriptions below.

• Interface

  idlCopy

  interface Name
  {
    [Declarations]
  };

  Attributes:

  • forward: Marks forward declaration, full declaration follows later.
  • uuid(IID): Interface GUID, required unless forward is set. Contents:
  • Method
  • Property

• Module

  idlCopy

  module Name
  {
    [Declarations]
  };

  Attributes:

  • dllname("filename.dll"): DLL (or SO) to import functions from Contents:
  • Constant
  • Method (will be translated as static imports)

• Alias

  idlCopy

  typedef TypeSpec Name; /* See "Array types" below */

  Attributes:

• Enum

  idlCopy

  typedef enum
  {
    EnumItem,
    EnumItem = Number
  } Name;

  Attributes:

  • enumsize(number): byte size of the enum, used to enforce packing

• Struct

  idlCopy

  typedef struct
  {
    TypeSpec Name; /* See "Array types" below */
  } Name;

  Attributes: Contents:

  • Field, see above

• Method

  idlCopy

  TypeSpec Name ( [ Parameter [, Parameter] ]);
  Parameter:
      [Attribute] [in|out|inout] TypeSpec Name /* See "Array types" below */

  Attributes for Parameters:

  • const: compiler hint that the parameter will not be modified. Note that this is different from the const that may be part of the TypeSpec proper.

  Parameters are by default passed by value. The [const] attribute does not change that, it only allows optimized checking for the consuming compiler. The direction modifiers allow changing this:

  		without [const]
  	nothing	COM standard
  	in	COM standard
  	out	by reference, input value is never used
  	inout	by reference

• Property

  idlCopy

  [readonly] attribute TypeSpec Name;

  Implies 2 Methods: TypeSpec GetName() and SetName(TypeSpec newval) (in order). Setter is only generated if readonly prefix is not given.

• Array Types

  idlCopy

  TypeSpec Name; /* No Array */
  TypeSpec Name[5]; /* Array with 5 elements, index 0..4 */
  TypeSpec Name[]; /* Dynamic Array (definition as pointer type is preferred for portability) */
  TypeSpec Name[5][4]; /* array[0..4] of array[0..3] of TypeSpec */

• Callback

  idlCopy

  typedef callback TypeSpec Name ( [ Parameter [, Parameter] ]);

  Function pointer commonly used for callbacks. Identical to Method decalaration, see above for full description. Note that in constrast to C(++), the pointer is implied and not attached to Name.

• Const

  idlCopy

  const TypeSpec Name = Value;

  Attributes for Parameters:

  • static_cast: Hint that the literal Value is not directly compatible to TypeSpec and may need an explicite type cast.

Refereces

• TP Lex & Yacc
• Plax & Pyacc Howto
• Freepascal h2pas utility
• XPIDL Data types
• XPIDL BFN Syntax
• MIDL Data types
• MIDL Token reference
• Inprise RIDL Syntax Examples