TODO
====

General
-------

* documentation
* parse way optimization
* implement member access control
* improve expression evaluation
* improve template support
* RTTI support
* better management of different targets for size and alignment of types
* shared type objects => faster type comparison, less memory consumption...
* GNU C/C++ extensions:
  - generalized lvalues => less restrictive isLvalue()
  - introduce variable name after initializer instead of before


Preprocessor
------------
- change macro expansion scheme to fit the standard, e.g.
  --- 
  #define hash_hash # ## #
  #define mkstr(a) # a 
  #define in_between(a) mkstr(a)
  #define join(c, d) in_between(c hash_hash d)
  join(x, y);
  ---
  should result in `"x ## y"' not in `" xy "'
- GNU extensions, e.g.
  ---
  #define FILE(x) <a/b/x>
  #include FILE(bar.h)
  ---
  results in `#include <a/b/ bar.h >' but GNU's cpp produces 
  `#include <a/b/bar.h>'


GNU Parser Extensions
---------------------

1. Thread-Local Storage
storage-class __thread

2. more built-in functions for C/C++

3. C/C++ offsetof
Calculation of real offset is not yet implemented.
Currently always returns 0.

4. __alignof__, with same syntax as for sizeof
Calculation of real alignment is not yet implemented.
Currently always returns 1.

5. Getting the Return or Frame Address of a Function
void * __builtin_return_address (unsigned int level);
void * __builtin_frame_address (unsigned int level);

6. Function Names as Strings
static const char __func__[] = "function-name";
__FUNCTION__ = __func__
__PRETTY_FUNCTION__ = void a::sub(int)

7. Case Ranges
switch (1) {
  case 1 ... 9: break;
}

8. Cast to a Union Type
union foo { int i; double d; };
int x;
double y;
union foo u;
u = (union foo) x;
u = (union foo) y;

9. Designated Initializers
int whitespace[256]
  = { [' '] = 1, ['\t'] = 1, ['\h'] = 1,
      ['\f'] = 1, ['\n'] = 1, ['\r'] = 1 };
struct point ptarray[10] = { [2].y = yv2, [2].x = xv2, [0].x = xv0 };

10. Compound Literals
structure = ((struct foo) {x + y, 'a', 0});

11. C: Non-Constant Initializers
void foo (float f, float g) {
  float beat_freqs[2] = { f-g, f+g };
}

12. Arithmetic on void- and Function-Pointers
In GNU C, addition and subtraction operations are supported on pointers to void and on 
pointers to functions. This is done by treating the size of a void or of a function as 1.
A consequence of this is that sizeof is also allowed on void and on function types, and 
returns 1. 

13. Non-Lvalue Arrays May Have Subscripts
struct foo {int a[4];};
struct foo f();
bar (int index){
 return f().a[index];
}

14. Slightly Looser Rules for Escaped Newlines
Recently, the preprocessor has relaxed its treatment of escaped newlines. Previously, 
the newline had to immediately follow a backslash. The current implementation allows 
whitespace in the form of spaces, horizontal and vertical tabs, and form feeds between 
the backslash and the subsequent newline.

15. Arrays of Variable Length, or Zero, in C/C++

16. Complex Numbers

17. Conditionals with Omitted Operands
x ? : y

18. Referring to a Type with typeof

19. Constructing Function Calls (done)
void * __builtin_apply_args ()
void * __builtin_apply (void (*function)(), void *arguments, size_t size)
void __builtin_return (void *result)

20. Nested Functions
foo (double a, double b) {
  double square (double z) { return z * z; }
  return square (a) + square (b);
}

21. Labels as Values
void *ptr;
ptr = &&foo;
goto *ptr;

22. C: Statements and Declarations in Expressions
({ int y = foo (); int z;
   if (y > 0) z = y;
   else z = - y;
   z; })

23. Locally Declared Labels
__label__ label;
__label__ label1, label2, /* ... */;