vfprintf.c

绝对正真的stdio.h的实现

		    else						      \
		      len = str2 - string - (ps.__count & 7);		      \
		  }							      \
	      }								      \
	    else							      \
	      len = strlen (string);					      \
	  }								      \
	else								      \
	  {								      \
	    const wchar_t *s2 = (const wchar_t *) string;		      \
	    mbstate_t mbstate;						      \
									      \
	    memset (&mbstate, '\0', sizeof (mbstate_t));		      \
									      \
	    if (prec >= 0)						      \
	      {								      \
		/* The string `s2' might not be NUL terminated.  */	      \
		if (__libc_use_alloca (prec))				      \
		  string = (char *) alloca (prec);			      \
		else if ((string = (char *) malloc (prec)) == NULL)	      \
		  {							      \
		    done = -1;						      \
		    goto all_done;					      \
		  }							      \
		else							      \
		  string_malloced = 1;					      \
		len = __wcsrtombs (string, &s2, prec, &mbstate);	      \
	      }								      \
	    else							      \
	      {								      \
		len = __wcsrtombs (NULL, &s2, 0, &mbstate);		      \
		if (len != (size_t) -1)					      \
		  {							      \
		    assert (__mbsinit (&mbstate));			      \
		    s2 = (const wchar_t *) string;			      \
		    if (__libc_use_alloca (len + 1))			      \
		      string = (char *) alloca (len + 1);		      \
		    else if ((string = (char *) malloc (len + 1)) == NULL)    \
		      {							      \
			done = -1;					      \
			goto all_done;					      \
		      }							      \
		    else						      \
		      string_malloced = 1;				      \
		    (void) __wcsrtombs (string, &s2, len + 1, &mbstate);      \
		  }							      \
	      }								      \
									      \
	    if (len == (size_t) -1)					      \
	      {								      \
	        /* Illegal wide-character string.  */			      \
		done = -1;						      \
		goto all_done;						      \
	      }								      \
	  }								      \
									      \
	if ((width -= len) < 0)						      \
	  {								      \
	    outstring (string, len);					      \
	    break;							      \
	  }								      \
									      \
	if (!left)							      \
	  PAD (' ');							      \
	outstring (string, len);					      \
	if (left)							      \
	  PAD (' ');							      \
	if (__builtin_expect (string_malloced, 0))			      \
	  free (string);						      \
      }									      \
      break;
#endif

  /* Orient the stream.  */
#ifdef ORIENT
  ORIENT;
#endif

  /* Sanity check of arguments.  */
  ARGCHECK (s, format);

#ifdef ORIENT
  /* Check for correct orientation.  */
  if (_IO_vtable_offset (s) == 0 &&
      _IO_fwide (s, sizeof (CHAR_T) == 1 ? -1 : 1)
      != (sizeof (CHAR_T) == 1 ? -1 : 1))
    /* The stream is already oriented otherwise.  */
    return EOF;
#endif

  if (UNBUFFERED_P (s))
    /* Use a helper function which will allocate a local temporary buffer
       for the stream and then call us again.  */
    return buffered_vfprintf (s, format, ap);

  /* Initialize local variables.  */
  done = 0;
  grouping = (const char *) -1;
#ifdef __va_copy
  /* This macro will be available soon in gcc's <stdarg.h>.  We need it
     since on some systems `va_list' is not an integral type.  */
  __va_copy (ap_save, ap);
#else
  ap_save = ap;
#endif
  nspecs_done = 0;

#ifdef COMPILE_WPRINTF
  /* Find the first format specifier.  */
  f = lead_str_end = __find_specwc ((const UCHAR_T *) format);
#else
  /* Put state for processing format string in initial state.  */
  memset (&mbstate, '\0', sizeof (mbstate_t));

  /* Find the first format specifier.  */
  f = lead_str_end = __find_specmb (format, &mbstate);
#endif

  /* Lock stream.  */
  _IO_cleanup_region_start ((void (*) (void *)) &_IO_funlockfile, s);
  _IO_flockfile (s);

  /* Write the literal text before the first format.  */
  outstring ((const UCHAR_T *) format,
	     lead_str_end - (const UCHAR_T *) format);

  /* If we only have to print a simple string, return now.  */
  if (*f == L_('\0'))
    goto all_done;

  /* Process whole format string.  */
  do
    {
#if defined HAVE_SUBTRACT_LOCAL_LABELS && defined SHARED
# define REF(Name) &&do_##Name - &&do_form_unknown
#else
# define REF(Name) &&do_##Name
#endif
#define LABEL(Name) do_##Name
      STEP0_3_TABLE;
      STEP4_TABLE;

      union printf_arg *args_value;	/* This is not used here but ... */
      int is_negative;	/* Flag for negative number.  */
      union
      {
	unsigned long long int longlong;
	unsigned long int word;
      } number;
      int base;
      union printf_arg the_arg;
      CHAR_T *string;	/* Pointer to argument string.  */
      int alt = 0;	/* Alternate format.  */
      int space = 0;	/* Use space prefix if no sign is needed.  */
      int left = 0;	/* Left-justify output.  */
      int showsign = 0;	/* Always begin with plus or minus sign.  */
      int group = 0;	/* Print numbers according grouping rules.  */
      int is_long_double = 0; /* Argument is long double/ long long int.  */
      int is_short = 0;	/* Argument is short int.  */
      int is_long = 0;	/* Argument is long int.  */
      int is_char = 0;	/* Argument is promoted (unsigned) char.  */
      int width = 0;	/* Width of output; 0 means none specified.  */
      int prec = -1;	/* Precision of output; -1 means none specified.  */
      /* This flag is set by the 'I' modifier and selects the use of the
	 `outdigits' as determined by the current locale.  */
      int use_outdigits = 0;
      UCHAR_T pad = L_(' ');/* Padding character.  */
      CHAR_T spec;

      workstart = NULL;
      workend = &work_buffer[sizeof (work_buffer) / sizeof (CHAR_T)];

      /* Get current character in format string.  */
      JUMP (*++f, step0_jumps);

      /* ' ' flag.  */
    LABEL (flag_space):
      space = 1;
      JUMP (*++f, step0_jumps);

      /* '+' flag.  */
    LABEL (flag_plus):
      showsign = 1;
      JUMP (*++f, step0_jumps);

      /* The '-' flag.  */
    LABEL (flag_minus):
      left = 1;
      pad = L_(' ');
      JUMP (*++f, step0_jumps);

      /* The '#' flag.  */
    LABEL (flag_hash):
      alt = 1;
      JUMP (*++f, step0_jumps);

      /* The '0' flag.  */
    LABEL (flag_zero):
      if (!left)
	pad = L_('0');
      JUMP (*++f, step0_jumps);

      /* The '\'' flag.  */
    LABEL (flag_quote):
      group = 1;

      if (grouping == (const char *) -1)
	{
#ifdef COMPILE_WPRINTF
	  thousands_sep = _NL_CURRENT_WORD (LC_NUMERIC,
					    _NL_NUMERIC_THOUSANDS_SEP_WC);
#else
	  thousands_sep = _NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP);
#endif

	  grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
	  if (*grouping == '\0' || *grouping == CHAR_MAX
#ifdef COMPILE_WPRINTF
	      || thousands_sep == L'\0'
#else
	      || *thousands_sep == '\0'
#endif
	      )
	    grouping = NULL;
	}
      JUMP (*++f, step0_jumps);

    LABEL (flag_i18n):
      use_outdigits = 1;
      JUMP (*++f, step0_jumps);

      /* Get width from argument.  */
    LABEL (width_asterics):
      {
	const UCHAR_T *tmp;	/* Temporary value.  */

	tmp = ++f;
	if (ISDIGIT (*tmp) && read_int (&tmp) && *tmp == L_('$'))
	  /* The width comes from a positional parameter.  */
	  goto do_positional;

	width = va_arg (ap, int);

	/* Negative width means left justified.  */
	if (width < 0)
	  {
	    width = -width;
	    pad = L_(' ');
	    left = 1;
	  }

	if (width + 32 >= (int) (sizeof (work_buffer)
				 / sizeof (work_buffer[0])))
	  {
	    /* We have to use a special buffer.  The "32" is just a safe
	       bet for all the output which is not counted in the width.  */
	    if (__libc_use_alloca ((width + 32) * sizeof (CHAR_T)))
	      workend = ((CHAR_T *) alloca ((width + 32) * sizeof (CHAR_T))
			 + (width + 32));
	    else
	      {
		workstart = (CHAR_T *) malloc ((width + 32) * sizeof (CHAR_T));
		if (workstart == NULL)
		  {
		    done = -1;
		    goto all_done;
		  }
		workend = workstart + (width + 32);
	      }
	  }
      }
      JUMP (*f, step1_jumps);

      /* Given width in format string.  */
    LABEL (width):
      width = read_int (&f);

      if (width + 32 >= (int) (sizeof (work_buffer) / sizeof (work_buffer[0])))
	{
	  /* We have to use a special buffer.  The "32" is just a safe
	     bet for all the output which is not counted in the width.  */
	  if (__libc_use_alloca ((width + 32) * sizeof (CHAR_T)))
	    workend = ((CHAR_T *) alloca ((width + 32) * sizeof (CHAR_T))
		       + (width + 32));
	  else
	    {
	      workstart = (CHAR_T *) malloc ((width + 32) * sizeof (CHAR_T));
	      if (workstart == NULL)
		{
		  done = -1;
		  goto all_done;
		}
	      workend = workstart + (width + 32);
	    }
	}
      if (*f == L_('$'))
	/* Oh, oh.  The argument comes from a positional parameter.  */
	goto do_positional;
      JUMP (*f, step1_jumps);

    LABEL (precision):
      ++f;
      if (*f == L_('*'))
	{
	  const UCHAR_T *tmp;	/* Temporary value.  */

	  tmp = ++f;
	  if (ISDIGIT (*tmp) && read_int (&tmp) > 0 && *tmp == L_('$'))
	    /* The precision comes from a positional parameter.  */
	    goto do_positional;

	  prec = va_arg (ap, int);

	  /* If the precision is negative the precision is omitted.  */
	  if (prec < 0)
	    prec = -1;
	}
      else if (ISDIGIT (*f))
	prec = read_int (&f);
      else
	prec = 0;
      if (prec > width
	  && prec + 32 > (int)(sizeof (work_buffer) / sizeof (work_buffer[0])))
	{
	  if (__libc_use_alloca ((prec + 32) * sizeof (CHAR_T)))
	    workend = ((CHAR_T *) alloca ((prec + 32) * sizeof (CHAR_T)))
		      + (prec + 32);
	  else
	    {
	      workstart = (CHAR_T *) malloc ((prec + 32) * sizeof (CHAR_T));
	      if (workstart == NULL)
		{
		  done = -1;
		  goto all_done;
		}
	      workend = workstart + (prec + 32);
	    }
	}
      JUMP (*f, step2_jumps);

      /* Process 'h' modifier.  There might another 'h' following.  */
    LABEL (mod_half):
      is_short = 1;
      JUMP (*++f, step3a_jumps);

      /* Process 'hh' modifier.  */
    LABEL (mod_halfhalf):
      is_short = 0;
      is_char = 1;
      JUMP (*++f, step4_jumps);

      /* Process 'l' modifier.  There might another 'l' following.  */
    LABEL (mod_long):
      is_long = 1;
      JUMP (*++f, step3b_jumps);

      /* Process 'L', 'q', or 'll' modifier.  No other modifier is
	 allowed to follow.  */
    LABEL (mod_longlong):
      is_long_double = 1;
      is_long = 1;
      JUMP (*++f, step4_jumps);

    LABEL (mod_size_t):
      is_long_double = sizeof (size_t) > sizeof (unsigned long int);
      is_long = sizeof (size_t) > sizeof (unsigned int);
      JUMP (*++f, step4_jumps);

    LABEL (mod_ptrdiff_t):
      is_long_double = sizeof (ptrdiff_t) > sizeof (unsigned long int);
      is_long = sizeof (ptrdiff_t) > sizeof (unsigned int);
      JUMP (*++f, step4_jumps);

    LABEL (mod_intmax_t):
      is_long_double = sizeof (intmax_t) > sizeof (unsigned long int);
      is_long = sizeof (intmax_t) > sizeof (unsigned int);
      JUMP (*++f, step4_jumps);

      /* Process current format.  */
      while (1)
	{
	  process_arg (((struct printf_spec *) NULL));
	  process_string_arg (((struct printf_spec *) NULL));