path: root/stdio-common/vfprintf-process-arg.c

/* Argument-processing fragment for vfprintf.
   Copyright (C) 1991-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

/* This file is included twice from vfprintf-internal.c, for standard
   and GNU-style positional (%N$) arguments.  Before that,
   process_arg_int etc. macros have to be defined to extract one
   argument of the appropriate type, in addition to the file-specific
   macros in vfprintf-internal.c.  */

{
  /* Start real work.  We know about all flags and modifiers and
     now process the wanted format specifier.  */

/* Process capability information according to the CHERI C Programming guide:
   https://github.com/CTSRD-CHERI/cheri-c-programming/wiki/Displaying-Capabilities */
#ifdef __CHERI_PURE_CAPABILITY__
LABEL (capability):
  /* CHERI capability.  */
  {
	uint64_t cap_perm = 0;
	uint64_t cap_base = 0;
	uint64_t cap_limit = 0;
	uint64_t cap_tag = 0;
	uint64_t cap_type = 0;
	outchar (L_(' '));
	outchar (L_('['));
	cap_perm = __builtin_cheri_perms_get (cap);
	if (cap_perm & CAP_PERM_LOAD)
	  outchar (L_('r'));
	if (cap_perm & CAP_PERM_STORE)
	  outchar (L_('w'));
	if (cap_perm & CAP_PERM_EXECUTE)
	  outchar (L_('x'));
	if (cap_perm & CAP_PERM_LOAD_CAP)
	  outchar (L_('R'));
	if (cap_perm & CAP_PERM_STORE_CAP)
	  outchar (L_('W'));
	if (cap_perm & CAP_PERM_EXECUTIVE)
	  outchar (L_('E'));
	outchar (L_(','));
	cap_base = __builtin_cheri_base_get (cap);
	number.word = (unsigned long int) cap_base;
	if (prec < 0)
	  prec = 1;
	else
	  pad = L_(' ');
	string = _itoa_word (number.word, workend, base, spec == L_('X'));
	prec = MAX (0, prec - (workend - string));
	width -= workend - string + prec;
	if (number.word != 0)
	  width -= 2;
	if (pad == L_(' '))
	  {
	    PAD (L_(' '));
	    width = 0;
	  }
	if (number.word != 0)
	  {
	    outchar (L_('0'));
	    outchar (spec);
	  }
	width += prec;
	PAD (L_('0'));
	outstring (string, workend - string);
	outchar (L_('-'));
	cap_limit = __builtin_cheri_length_get (cap) + cap_base;
	number.word = (unsigned long int) cap_limit;
	if (prec < 0)
	  prec = 1;
	else
	  pad = L_(' ');
	string = _itoa_word (number.word, workend, base, spec == L_('X'));
	prec = MAX (0, prec - (workend - string));
	width -= workend - string + prec;
	if (number.word != 0)
	  width -= 2;
	if (pad == L_(' '))
	  {
	    PAD (L_(' '));
	    width = 0;
	  }
	if (number.word != 0)
	  {
	    outchar (L_('0'));
	    outchar (spec);
	  }
	width += prec;
	PAD (L_('0'));
	outstring (string, workend - string);
	outchar (L_(']'));
	cap_tag = __builtin_cheri_tag_get (cap);
	if (!cap_tag)
	  {
	    outchar (L_(' '));
	    outchar (L_('('));
	    outstring ("invalid", 8);
	    outchar (L_(')'));
	    break;
	  }
	cap_type = __builtin_cheri_type_get (cap);
	if (cap_type != 0)
	  {
	    if (cap_type == 1)
	      {
		outchar (L_(' '));
		outchar (L_('('));
		outstring ("sentry", 7);
		outchar (L_(')'));
	      }
	    else
	      {
		outchar (L_(' '));
		outchar (L_('('));
		outstring ("sealed", 7);
		outchar (L_(')'));
	      }
	  }
      }
      break;
#endif

LABEL (form_percent):
  /* Write a literal "%".  */
  outchar (L_('%'));
  break;

LABEL (form_integer):
  /* Signed decimal integer.  */
  base = 10;

  if (is_longlong)
    {
      long long int signed_number = process_arg_long_long_int ();
      is_negative = signed_number < 0;
      number.longlong = is_negative ? (- signed_number) : signed_number;

      goto LABEL (longlong_number);
    }
  else
    {
      long int signed_number;
      if (is_long_num)
        signed_number = process_arg_long_int ();
      else if (is_char)
        signed_number = (signed char) process_arg_unsigned_int ();
      else if (!is_short)
        signed_number = process_arg_int ();
      else
        signed_number = (short int) process_arg_unsigned_int ();

      is_negative = signed_number < 0;
      number.word = is_negative ? (- signed_number) : signed_number;

      goto LABEL (number);
    }
  /* NOTREACHED */

LABEL (form_unsigned):
  /* Unsigned decimal integer.  */
  base = 10;
  goto LABEL (unsigned_number);
  /* NOTREACHED */

LABEL (form_octal):
  /* Unsigned octal integer.  */
  base = 8;
  goto LABEL (unsigned_number);
  /* NOTREACHED */

LABEL (form_hexa):
  /* Unsigned hexadecimal integer.  */
  base = 16;
  goto LABEL (unsigned_number);
  /* NOTREACHED */

LABEL (form_binary):
  /* Unsigned binary integer.  */
  base = 2;
  goto LABEL (unsigned_number);
  /* NOTREACHED */

LABEL (unsigned_number):      /* Unsigned number of base BASE.  */

  /* ISO specifies the `+' and ` ' flags only for signed
     conversions.  */
  is_negative = 0;
  showsign = 0;
  space = 0;

  if (is_longlong)
    {
      number.longlong = process_arg_unsigned_long_long_int ();

      LABEL (longlong_number):
      if (prec < 0)
        /* Supply a default precision if none was given.  */
        prec = 1;
      else
        /* We have to take care for the '0' flag.  If a precision
           is given it must be ignored.  */
        pad = L_(' ');

      /* If the precision is 0 and the number is 0 nothing has to
         be written for the number, except for the 'o' format in
         alternate form.  */
      if (prec == 0 && number.longlong == 0)
        {
          string = workend;
          if (base == 8 && alt)
            *--string = L_('0');
        }
      else
        {
          /* Put the number in WORK.  */
          string = _itoa (number.longlong, workend, base,
                          spec == L_('X'));
          if (group && grouping)
            string = group_number (work_buffer, string, workend,
                                   grouping, thousands_sep);
          if (use_outdigits && base == 10)
            string = _i18n_number_rewrite (string, workend, workend);
        }
      /* Simplify further test for num != 0.  */
      number.word = number.longlong != 0;
    }
  else
    {
      if (is_long_num)
        number.word = process_arg_unsigned_long_int ();
      else if (is_char)
        number.word = (unsigned char) process_arg_unsigned_int ();
      else if (!is_short)
        number.word = process_arg_unsigned_int ();
      else
        number.word = (unsigned short int) process_arg_unsigned_int ();

      LABEL (number):
      if (prec < 0)
        /* Supply a default precision if none was given.  */
        prec = 1;
      else
        /* We have to take care for the '0' flag.  If a precision
           is given it must be ignored.  */
        pad = L_(' ');

      /* If the precision is 0 and the number is 0 nothing has to
         be written for the number, except for the 'o' format in
         alternate form.  */
      if (prec == 0 && number.word == 0)
        {
          string = workend;
          if (base == 8 && alt)
            *--string = L_('0');
        }
      else
        {
          /* Put the number in WORK.  */
          string = _itoa_word (number.word, workend, base,
                               spec == L_('X'));
          if (group && grouping)
            string = group_number (work_buffer, string, workend,
                                   grouping, thousands_sep);
          if (use_outdigits && base == 10)
            string = _i18n_number_rewrite (string, workend, workend);
        }
    }

  if (prec <= workend - string && number.word != 0 && alt && base == 8)
    /* Add octal marker.  */
    *--string = L_('0');

  prec = MAX (0, prec - (workend - string));

  if (!left)
    {
      width -= workend - string + prec;

      if (number.word != 0 && alt && (base == 16 || base == 2))
        /* Account for 0X, 0x, 0B or 0b hex or binary marker.  */
        width -= 2;

      if (is_negative || showsign || space)
        --width;

      if (pad == L_(' '))
        {
          PAD (L_(' '));
          width = 0;
        }

      if (is_negative)
        outchar (L_('-'));
      else if (showsign)
        outchar (L_('+'));
      else if (space)
        outchar (L_(' '));

      if (number.word != 0 && alt && (base == 16 || base == 2))
        {
          outchar (L_('0'));
          outchar (spec);
        }

      width += prec;
      PAD (L_('0'));

      outstring (string, workend - string);

#ifdef __CHERI_PURE_CAPABILITY__
      if (is_cap == 1)
	goto LABEL(capability);
#endif

      break;
    }
  else
    {
      if (is_negative)
        {
          outchar (L_('-'));
          --width;
        }
      else if (showsign)
        {
          outchar (L_('+'));
          --width;
        }
      else if (space)
        {
          outchar (L_(' '));
          --width;
        }

      if (number.word != 0 && alt && (base == 16 || base == 2))
        {
          outchar (L_('0'));
          outchar (spec);
          width -= 2;
        }

      width -= workend - string + prec;

      if (prec > 0)
        {
          int temp = width;
          width = prec;
          PAD (L_('0'));
          width = temp;
        }

      outstring (string, workend - string);

      PAD (L_(' '));
      break;
    }

LABEL (form_pointer):
  /* Generic pointer.  */
  {
    const void *ptr = process_arg_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;
#ifdef __CHERI_PURE_CAPABILITY__
	if (alt == 1)
	  {
	    cap = ptr;
	    is_cap = 1;
	  }
#endif
        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;
        /* This is a wide string iff compiling wprintf.  */
        is_long = sizeof (CHAR_T) > 1;
        goto LABEL (print_string);
      }
  }
  /* NOTREACHED */

LABEL (form_number):
  if ((mode_flags & PRINTF_FORTIFY) != 0)
    {
      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.  */
  void *ptrptr = process_arg_pointer ();
  if (is_longlong)
    *(long long int *) ptrptr = done;
  else if (is_long_num)
    *(long int *) ptrptr = done;
  else if (is_char)
    *(char *) ptrptr = done;
  else if (!is_short)
    *(int *) ptrptr = done;
  else
    *(short int *) ptrptr = done;
  break;

LABEL (form_strerror):
  /* Print description of error ERRNO.  */
  if (alt)
    string = (CHAR_T *) __get_errname (save_errno);
  else
    string = (CHAR_T *) __strerror_r (save_errno, (char *) work_buffer,
                                      WORK_BUFFER_SIZE * sizeof (CHAR_T));
  if (string == NULL)
    {
      /* Print as a decimal number. */
      base = 10;
      is_negative = save_errno < 0;
      number.word = save_errno;
      if (is_negative)
        number.word = -number.word;
      goto LABEL (number);
    }
  else
    {
      is_long = 0;  /* This is no wide-char string.  */
      goto LABEL (print_string);
    }

LABEL (form_character):
  /* Character.  */
  if (is_long)
    goto LABEL (form_wcharacter);
  --width;  /* Account for the character itself.  */
  if (!left)
    PAD (L_(' '));
#ifdef COMPILE_WPRINTF
  outchar (__btowc ((unsigned char) process_arg_int ())); /* Promoted. */
#else
  outchar ((unsigned char) process_arg_int ()); /* Promoted.  */
#endif
  if (left)
    PAD (L_(' '));
  break;

LABEL (form_string):
  {
    size_t len;

    /* The string argument could in fact be `char *' or `wchar_t *'.
       But this should not make a difference here.  */
#ifdef COMPILE_WPRINTF
    string = (CHAR_T *) process_arg_wstring ();
#else
    string = (CHAR_T *) process_arg_string ();
#endif
    /* Entry point for printing other strings.  */
    LABEL (print_string):

    if (string == NULL)
      {
        /* Write "(null)" if there's space.  */
        if (prec == -1 || prec >= (int) array_length (null) - 1)
          {
            string = (CHAR_T *) null;
            len = array_length (null) - 1;
          }
        else
          {
            string = (CHAR_T *) L"";
            len = 0;
          }
      }
    else if (!is_long && spec != L_('S'))
      {
#ifdef COMPILE_WPRINTF
        done = outstring_converted_wide_string
          (s, (const char *) string, prec, width, left, done);
        if (done < 0)
          goto all_done;
        /* The padding has already been written.  */
        break;
#else
        if (prec != -1)
          /* Search for the end of the string, but don't search past
             the length (in bytes) specified by the precision.  */
          len = __strnlen (string, prec);
        else
          len = strlen (string);
#endif
      }
    else
      {
#ifdef COMPILE_WPRINTF
        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);
#else
        done = outstring_converted_wide_string
          (s, (const wchar_t *) string, prec, width, left, done);
        if (done < 0)
          goto all_done;
        /* The padding has already been written.  */
        break;
#endif
      }

    if ((width -= len) < 0)
      {
        outstring (string, len);
        break;
      }

    if (!left)
      PAD (L_(' '));
    outstring (string, len);
    if (left)
      PAD (L_(' '));
  }
  break;

#ifdef COMPILE_WPRINTF
LABEL (form_wcharacter):
  {
    /* Wide character.  */
    --width;
    if (!left)
      PAD (L' ');
    outchar (process_arg_wchar_t ());
    if (left)
      PAD (L' ');
  }
  break;

#else /* !COMPILE_WPRINTF */
LABEL (form_wcharacter):
  {
    /* Wide character.  */
    char buf[MB_LEN_MAX];
    mbstate_t mbstate;
    size_t len;

    memset (&mbstate, '\0', sizeof (mbstate_t));
    len = __wcrtomb (buf, process_arg_wchar_t (), &mbstate);
    if (len == (size_t) -1)
      {
        /* Something went wrong during the conversion.  Bail out.  */
        done = -1;
        goto all_done;
      }
    width -= len;
    if (!left)
      PAD (' ');
    outstring (buf, len);
    if (left)
      PAD (' ');
  }
  break;
#endif /* !COMPILE_WPRINTF */
}