vfprintf.c

绝对正真的stdio.h的实现

					.left = left,			      \
					.showsign = showsign,		      \
					.group = group,			      \
					.pad = pad,			      \
					.extra = 0,			      \
					.i18n = use_outdigits,		      \
					.wide = sizeof (CHAR_T) != 1 };	      \
									      \
	    if (is_long_double)						      \
	      the_arg.pa_long_double = va_arg (ap, long double);	      \
	    else							      \
	      the_arg.pa_double = va_arg (ap, double);			      \
	    ptr = (const void *) &the_arg;				      \
									      \
	    function_done = __printf_fp (s, &info, &ptr);		      \
	  }								      \
	else								      \
	  {								      \
	    ptr = (const void *) &args_value[fspec->data_arg];		      \
									      \
	    function_done = __printf_fp (s, &fspec->info, &ptr);	      \
	  }								      \
									      \
	if (function_done < 0)						      \
	  {								      \
	    /* Error in print handler.  */				      \
	    done = -1;							      \
	    goto all_done;						      \
	  }								      \
									      \
	done += function_done;						      \
      }									      \
      break;								      \
									      \
    LABEL (form_floathex):						      \
      {									      \
        /* Floating point number printed as hexadecimal number.  */	      \
	const void *ptr;						      \
	int function_done;						      \
									      \
	if (fspec == NULL)						      \
	  {								      \
	    struct printf_info info = { .prec = prec,			      \
					.width = width,			      \
					.spec = spec,			      \
					.is_long_double = is_long_double,     \
					.is_short = is_short,		      \
					.is_long = is_long,		      \
					.alt = alt,			      \
					.space = space,			      \
					.left = left,			      \
					.showsign = showsign,		      \
					.group = group,			      \
					.pad = pad,			      \
					.extra = 0,			      \
					.wide = sizeof (CHAR_T) != 1 };	      \
									      \
	    if (is_long_double)						      \
	      the_arg.pa_long_double = va_arg (ap, long double);	      \
	    else							      \
	      the_arg.pa_double = va_arg (ap, double);			      \
	    ptr = (const void *) &the_arg;				      \
									      \
	    function_done = __printf_fphex (s, &info, &ptr);		      \
	  }								      \
	else								      \
	  {								      \
	    ptr = (const void *) &args_value[fspec->data_arg];		      \
									      \
	    function_done = __printf_fphex (s, &fspec->info, &ptr);	      \
	  }								      \
									      \
	if (function_done < 0)						      \
	  {								      \
	    /* Error in print handler.  */				      \
	    done = -1;							      \
	    goto all_done;						      \
	  }								      \
									      \
	done += function_done;						      \
      }									      \
      break;								      \
									      \
    LABEL (form_pointer):						      \
      /* Generic pointer.  */						      \
      {									      \
	const void *ptr;						      \
	if (fspec == NULL)						      \
	  ptr = va_arg (ap, void *);					      \
	else								      \
	  ptr = args_value[fspec->data_arg].pa_pointer;			      \
	if (ptr != NULL)						      \
	  {								      \
	    /* If the pointer is not NULL, write it as a %#x spec.  */	      \
	    base = 16;							      \
	    number.word = (unsigned long int) ptr;			      \
	    is_negative = 0;						      \
	    alt = 1;							      \
	    group = 0;							      \
	    spec = L_('x');						      \
	    goto LABEL (number);					      \
	  }								      \
	else								      \
	  {								      \
	    /* Write "(nil)" for a nil pointer.  */			      \
	    string = (CHAR_T *) L_("(nil)");				      \
	    /* Make sure the full string "(nil)" is printed.  */	      \
	    if (prec < 5)						      \
	      prec = 5;							      \
	    is_long = 0;	/* This is no wide-char string.  */	      \
	    goto LABEL (print_string);					      \
	  }								      \
      }									      \
      /* NOTREACHED */							      \
									      \
    LABEL (form_number):						      \
      if (s->_flags2 & _IO_FLAGS2_FORTIFY)				      \
	{								      \
	  if (! readonly_format)					      \
	    {								      \
	      extern int __readonly_area (const void *, size_t)		      \
		attribute_hidden;					      \
	      readonly_format						      \
		= __readonly_area (format, ((STR_LEN (format) + 1)	      \
					    * sizeof (CHAR_T)));	      \
	    }								      \
	  if (readonly_format < 0)					      \
	    __libc_fatal ("*** %n in writable segment detected ***\n");	      \
	}								      \
      /* Answer the count of characters written.  */			      \
      if (fspec == NULL)						      \
	{								      \
	  if (is_longlong)						      \
	    *(long long int *) va_arg (ap, void *) = done;		      \
	  else if (is_long_num)						      \
	    *(long int *) va_arg (ap, void *) = done;			      \
	  else if (is_char)						      \
	    *(char *) va_arg (ap, void *) = done;			      \
	  else if (!is_short)						      \
	    *(int *) va_arg (ap, void *) = done;			      \
	  else								      \
	    *(short int *) va_arg (ap, void *) = done;			      \
	}								      \
      else								      \
	if (is_longlong)						      \
	  *(long long int *) args_value[fspec->data_arg].pa_pointer = done;   \
	else if (is_long_num)						      \
	  *(long int *) args_value[fspec->data_arg].pa_pointer = done;	      \
	else if (is_char)						      \
	  *(char *) args_value[fspec->data_arg].pa_pointer = done;	      \
	else if (!is_short)						      \
	  *(int *) args_value[fspec->data_arg].pa_pointer = done;	      \
	else								      \
	  *(short int *) args_value[fspec->data_arg].pa_pointer = done;	      \
      break;								      \
									      \
    LABEL (form_strerror):						      \
      /* Print description of error ERRNO.  */				      \
      string =								      \
	(CHAR_T *) __strerror_r (save_errno, (char *) work_buffer,	      \
				 sizeof work_buffer);			      \
      is_long = 0;		/* This is no wide-char string.  */	      \
      goto LABEL (print_string)

#ifdef COMPILE_WPRINTF
# define process_string_arg(fspec) \
    LABEL (form_character):						      \
      /* Character.  */							      \
      if (is_long)							      \
	goto LABEL (form_wcharacter);					      \
      --width;	/* Account for the character itself.  */		      \
      if (!left)							      \
	PAD (L' ');							      \
      if (fspec == NULL)						      \
	outchar (__btowc ((unsigned char) va_arg (ap, int))); /* Promoted. */ \
      else								      \
	outchar (__btowc ((unsigned char)				      \
			  args_value[fspec->data_arg].pa_int));		      \
      if (left)								      \
	PAD (L' ');							      \
      break;								      \
									      \
    LABEL (form_wcharacter):						      \
      {									      \
	/* Wide character.  */						      \
	--width;							      \
	if (!left)							      \
	  PAD (L' ');							      \
        if (fspec == NULL)						      \
	  outchar (va_arg (ap, wchar_t));				      \
	else								      \
	  outchar (args_value[fspec->data_arg].pa_wchar);		      \
	if (left)							      \
	  PAD (L' ');							      \
      }									      \
      break;								      \
									      \
    LABEL (form_string):						      \
      {									      \
	size_t len;							      \
	int string_malloced;						      \
									      \
	/* The string argument could in fact be `char *' or `wchar_t *'.      \
	   But this should not make a difference here.  */		      \
	if (fspec == NULL)						      \
	  string = (CHAR_T *) va_arg (ap, const wchar_t *);		      \
	else								      \
	  string = (CHAR_T *) args_value[fspec->data_arg].pa_wstring;	      \
									      \
	/* Entry point for printing other strings.  */			      \
      LABEL (print_string):						      \
									      \
	string_malloced = 0;						      \
	if (string == NULL)						      \
	  {								      \
	    /* Write "(null)" if there's space.  */			      \
	    if (prec == -1						      \
		|| prec >= (int) (sizeof (null) / sizeof (null[0])) - 1)      \
	      {								      \
		string = (CHAR_T *) null;				      \
		len = (sizeof (null) / sizeof (null[0])) - 1;		      \
	      }								      \
	    else							      \
	      {								      \
		string = (CHAR_T *) L"";				      \
		len = 0;						      \
	      }								      \
	  }								      \
	else if (!is_long && spec != L_('S'))				      \
	  {								      \
	    /* This is complicated.  We have to transform the multibyte	      \
	       string into a wide character string.  */			      \
	    const char *mbs = (const char *) string;			      \
	    mbstate_t mbstate;						      \
									      \
	    len = prec != -1 ? (size_t) prec : strlen (mbs);		      \
									      \
	    /* Allocate dynamically an array which definitely is long	      \
	       enough for the wide character version.  */		      \
	    if (__libc_use_alloca (len * sizeof (wchar_t)))		      \
	      string = (CHAR_T *) alloca (len * sizeof (wchar_t));	      \
	    else if ((string = (CHAR_T *) malloc (len * sizeof (wchar_t)))    \
		     == NULL)						      \
	      {								      \
		done = -1;						      \
		goto all_done;						      \
	      }								      \
	    else							      \
	      string_malloced = 1;					      \
									      \
	    memset (&mbstate, '\0', sizeof (mbstate_t));		      \
	    len = __mbsrtowcs (string, &mbs, len, &mbstate);		      \
	    if (len == (size_t) -1)					      \
	      {								      \
		/* Illegal multibyte character.  */			      \
		done = -1;						      \
		goto all_done;						      \
	      }								      \
	  }								      \
	else								      \
	  {								      \
	    if (prec != -1)						      \
	      /* Search for the end of the string, but don't search past      \
		 the length specified by the precision.  */		      \
	      len = __wcsnlen (string, prec);				      \
	    else							      \
	      len = __wcslen (string);					      \
	  }								      \
									      \
	if ((width -= len) < 0)						      \
	  {								      \
	    outstring (string, len);					      \
	    break;							      \
	  }								      \
									      \
	if (!left)							      \
	  PAD (L' ');							      \
	outstring (string, len);					      \
	if (left)							      \
	  PAD (L' ');							      \
	if (__builtin_expect (string_malloced, 0))			      \
	  free (string);						      \
      }									      \
      break;
#else
# define process_string_arg(fspec) \
    LABEL (form_character):						      \
      /* Character.  */							      \
      if (is_long)							      \
	goto LABEL (form_wcharacter);					      \
      --width;	/* Account for the character itself.  */		      \
      if (!left)							      \
	PAD (' ');							      \
      if (fspec == NULL)						      \
	outchar ((unsigned char) va_arg (ap, int)); /* Promoted.  */	      \
      else								      \
	outchar ((unsigned char) args_value[fspec->data_arg].pa_int);	      \
      if (left)								      \
	PAD (' ');							      \
      break;								      \
									      \
    LABEL (form_wcharacter):						      \
      {									      \
	/* Wide character.  */						      \
	char buf[MB_CUR_MAX];						      \
	mbstate_t mbstate;						      \
	size_t len;							      \
									      \
	memset (&mbstate, '\0', sizeof (mbstate_t));			      \
	len = __wcrtomb (buf, (fspec == NULL ? va_arg (ap, wchar_t)	      \
			       : args_value[fspec->data_arg].pa_wchar),	      \
			 &mbstate);					      \
	if (len == (size_t) -1)						      \
	  {								      \
	    /* Something went wron gduring the conversion.  Bail out.  */     \
	    done = -1;							      \
	    goto all_done;						      \
	  }								      \
	width -= len;							      \
	if (!left)							      \
	  PAD (' ');							      \
	outstring (buf, len);						      \
	if (left)							      \
	  PAD (' ');							      \
      }									      \
      break;								      \
									      \
    LABEL (form_string):						      \
      {									      \
	size_t len;							      \
	int string_malloced;						      \
									      \
	/* The string argument could in fact be `char *' or `wchar_t *'.      \
	   But this should not make a difference here.  */		      \
	if (fspec == NULL)						      \
	  string = (char *) va_arg (ap, const char *);			      \
	else								      \
	  string = (char *) args_value[fspec->data_arg].pa_string;	      \
									      \
	/* Entry point for printing other strings.  */			      \
      LABEL (print_string):						      \
									      \
	string_malloced = 0;						      \
	if (string == NULL)						      \
	  {								      \
	    /* Write "(null)" if there's space.  */			      \
	    if (prec == -1 || prec >= (int) sizeof (null) - 1)		      \
	      {								      \
		string = (char *) null;					      \
		len = sizeof (null) - 1;				      \
	      }								      \
	    else							      \
	      {								      \
		string = (char *) "";					      \
		len = 0;						      \
	      }								      \
	  }								      \
	else if (!is_long && spec != L_('S'))				      \
	  {								      \
	    if (prec != -1)						      \
	      {								      \
		/* Search for the end of the string, but don't search past    \
		   the length (in bytes) specified by the precision.  Also    \
		   don't use incomplete characters.  */			      \
		if (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MB_CUR_MAX) == 1)   \
		  len = __strnlen (string, prec);			      \
		else							      \
		  {							      \
		    /* In case we have a multibyte character set the	      \
		       situation is more compilcated.  We must not copy	      \
		       bytes at the end which form an incomplete character. */\
		    wchar_t ignore[prec];				      \
		    const char *str2 = string;				      \
		    mbstate_t ps;					      \
									      \
		    memset (&ps, '\0', sizeof (ps));			      \
		    if (__mbsnrtowcs (ignore, &str2, prec, prec, &ps)	      \
			== (size_t) -1)					      \
		      {							      \
			done = -1;					      \
			goto all_done;					      \
		      }							      \
		    if (str2 == NULL)					      \
		      len = strlen (string);				      \