include/stdarg.h

   1 #ifndef _STDARG_H
   2 #define _STDARG_H
   3
   4 #ifdef __x86_64__
   5 #include <stdlib.h>
   6
   7 /* GCC compatible definition of va_list. */
   8 struct __va_list_struct {
   9     unsigned int gp_offset;
  10     unsigned int fp_offset;
  11     union {
  12         unsigned int overflow_offset;
  13         char *overflow_arg_area;
  14     };
  15     char *reg_save_area;
  16 };
  17
  18 typedef struct __va_list_struct *va_list;
  19
  20 /* we use __builtin_(malloc|free) to avoid #define malloc tcc_malloc */
  21 /* XXX: this lacks the support of aggregated types. */
  22 #define va_start(ap, last)                                              \
  23     (ap = (va_list)__builtin_malloc(sizeof(struct __va_list_struct)),   \
  24      *ap = *(struct __va_list_struct*)(                                 \
  25          (char*)__builtin_frame_address(0) - 16),                       \
  26      ap->overflow_arg_area = ((char *)__builtin_frame_address(0) +      \
  27                               ap->overflow_offset),                     \
  28      ap->reg_save_area = (char *)__builtin_frame_address(0) - 176 - 16  \
  29         )
  30 #define va_arg(ap, type)                                        \
  31     (*(type*)(__builtin_types_compatible_p(type, long double)   \
  32               ? (ap->overflow_arg_area += 16,                   \
  33                  ap->overflow_arg_area - 16)                    \
  34               : __builtin_types_compatible_p(type, double)      \
  35               ? (ap->fp_offset < 128 + 48                       \
  36                  ? (ap->fp_offset += 16,                        \
  37                     ap->reg_save_area + ap->fp_offset - 16)     \
  38                  : (ap->overflow_arg_area += 8,                 \
  39                     ap->overflow_arg_area - 8))                 \
  40               : (ap->gp_offset < 48                             \
  41                  ? (ap->gp_offset += 8,                         \
  42                     ap->reg_save_area + ap->gp_offset - 8)      \
  43                  : (ap->overflow_arg_area += 8,                 \
  44                     ap->overflow_arg_area - 8))                 \
  45         ))
  46 #define va_copy(dest, src)                                      \
  47     ((dest) = (va_list)malloc(sizeof(struct __va_list_struct)), \
  48      *(dest) = *(src))
  49 #define va_end(ap) __builtin_free(ap)
  50
  51 #else
  52
  53 typedef char *va_list;
  54
  55 /* only correct for i386 */
  56 #define va_start(ap,last) ap = ((char *)&(last)) + ((sizeof(last)+3)&~3)
  57 #define va_arg(ap,type) (ap += (sizeof(type)+3)&~3, *(type *)(ap - ((sizeof(type)+3)&~3)))
  58 #define va_copy(dest, src) (dest) = (src)
  59 #define va_end(ap)
  60
  61 #endif
  62
  63 /* fix a buggy dependency on GCC in libio.h */
  64 typedef va_list __gnuc_va_list;
  65 #define _VA_LIST_DEFINED
  66
  67 #endif /* _STDARG_H */