vfscanf.c

Newlib 嵌入式 C库 标准实现代码

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
FUNCTION
<<vfscanf>>, <<vscanf>>, <<vsscanf>>---format argument list

INDEX
	vfscanf
INDEX
	vscanf
INDEX
	vsscanf

ANSI_SYNOPSIS
	#include <stdio.h>
	#include <stdarg.h>
	int vscanf(const char *<[fmt]>, va_list <[list]>);
	int vfscanf(FILE *<[fp]>, const char *<[fmt]>, va_list <[list]>);
	int vsscanf(const char *<[str]>, const char *<[fmt]>, va_list <[list]>);

	int _vscanf_r(struct _reent *<[reent]>, const char *<[fmt]>, 
                       va_list <[list]>);
	int _vfscanf_r(struct _reent *<[reent]>, FILE *<[fp]>, const char *<[fmt]>, 
                       va_list <[list]>);
	int _vsscanf_r(struct _reent *<[reent]>, const char *<[str]>,
                       const char *<[fmt]>, va_list <[list]>);

TRAD_SYNOPSIS
	#include <stdio.h>
	#include <varargs.h>
	int vscanf( <[fmt]>, <[ist]>)
	char *<[fmt]>;
	va_list <[list]>;

	int vfscanf( <[fp]>, <[fmt]>, <[list]>)
	FILE *<[fp]>;
	char *<[fmt]>;
	va_list <[list]>;
	
	int vsscanf( <[str]>, <[fmt]>, <[list]>)
	char *<[str]>;
	char *<[fmt]>;
	va_list <[list]>;

	int _vscanf_r( <[reent]>, <[fmt]>, <[ist]>)
	struct _reent *<[reent]>;
	char *<[fmt]>;
	va_list <[list]>;

	int _vfscanf_r( <[reent]>, <[fp]>, <[fmt]>, <[list]>)
	struct _reent *<[reent]>;
	FILE *<[fp]>;
	char *<[fmt]>;
	va_list <[list]>;
	
	int _vsscanf_r( <[reent]>, <[str]>, <[fmt]>, <[list]>)
	struct _reent *<[reent]>;
	char *<[str]>;
	char *<[fmt]>;
	va_list <[list]>;

DESCRIPTION
<<vscanf>>, <<vfscanf>>, and <<vsscanf>> are (respectively) variants
of <<scanf>>, <<fscanf>>, and <<sscanf>>.  They differ only in 
allowing their caller to pass the variable argument list as a 
<<va_list>> object (initialized by <<va_start>>) rather than 
directly accepting a variable number of arguments.

RETURNS
The return values are consistent with the corresponding functions:
<<vscanf>> returns the number of input fields successfully scanned,
converted, and stored; the return value does not include scanned
fields which were not stored.  

If <<vscanf>> attempts to read at end-of-file, the return value 
is <<EOF>>.

If no fields were stored, the return value is <<0>>.

The routines <<_vscanf_r>>, <<_vfscanf_f>>, and <<_vsscanf_r>> are
reentrant versions which take an additional first parameter which points to the
reentrancy structure.

PORTABILITY
These are GNU extensions.

Supporting OS subroutines required:
*/

#include <_ansi.h>
#include <reent.h>
#include <newlib.h>
#include <ctype.h>
#include <wctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <limits.h>
#include <wchar.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#include "local.h"

#ifdef INTEGER_ONLY
#define VFSCANF vfiscanf
#define _VFSCANF_R _vfiscanf_r
#define __SVFSCANF __svfiscanf
#define __SVFSCANF_R __svfiscanf_r
#else
#define VFSCANF vfscanf
#define _VFSCANF_R _vfscanf_r
#define __SVFSCANF __svfscanf
#define __SVFSCANF_R __svfscanf_r
#ifndef NO_FLOATING_POINT
#define FLOATING_POINT
#endif
#endif

#ifdef FLOATING_POINT
#include <math.h>
#include <float.h>

/* Currently a test is made to see if long double processing is warranted.
   This could be changed in the future should the _ldtoa_r code be
   preferred over _dtoa_r.  */
#define _NO_LONGDBL
#if defined _WANT_IO_LONG_DOUBLE && (LDBL_MANT_DIG > DBL_MANT_DIG)
#undef _NO_LONGDBL
extern _LONG_DOUBLE _strtold _PARAMS((char *s, char **sptr));
#endif

#include "floatio.h"

#if ((MAXEXP+MAXFRACT+3) > MB_LEN_MAX)
#  define BUF (MAXEXP+MAXFRACT+3)        /* 3 = sign + decimal point + NUL */
#else
#  define BUF MB_LEN_MAX
#endif

/* An upper bound for how long a long prints in decimal.  4 / 13 approximates
   log (2).  Add one char for roundoff compensation and one for the sign.  */
#define MAX_LONG_LEN ((CHAR_BIT * sizeof (long)  - 1) * 4 / 13 + 2)
#else
#define	BUF	40
#endif

#define _NO_LONGLONG
#if defined _WANT_IO_LONG_LONG \
	&& (defined __GNUC__ || __STDC_VERSION__ >= 199901L)
# undef _NO_LONGLONG
#endif

#define _NO_POS_ARGS
#ifdef _WANT_IO_POS_ARGS
# undef _NO_POS_ARGS
# ifdef NL_ARGMAX
#  define MAX_POS_ARGS NL_ARGMAX
# else
#  define MAX_POS_ARGS 32
# endif

static void * get_arg (int, va_list *, int *, void **);
#endif /* _WANT_IO_POS_ARGS */

/*
 * Flags used during conversion.
 */

#define	LONG		0x01	/* l: long or double */
#define	LONGDBL		0x02	/* L/ll: long double or long long */
#define	SHORT		0x04	/* h: short */
#define CHAR		0x08	/* hh: 8 bit integer */
#define	SUPPRESS	0x10	/* suppress assignment */
#define	POINTER		0x20	/* weird %p pointer (`fake hex') */
#define	NOSKIP		0x40	/* do not skip blanks */

/*
 * The following are used in numeric conversions only:
 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
 */

#define	SIGNOK		0x80	/* +/- is (still) legal */
#define	NDIGITS		0x100	/* no digits detected */

#define	DPTOK		0x200	/* (float) decimal point is still legal */
#define	EXPOK		0x400	/* (float) exponent (e+3, etc) still legal */

#define	PFXOK		0x200	/* 0x prefix is (still) legal */
#define	NZDIGITS	0x400	/* no zero digits detected */
#define	NNZDIGITS	0x800	/* no non-zero digits detected */

/*
 * Conversion types.
 */

#define	CT_CHAR		0	/* %c conversion */
#define	CT_CCL		1	/* %[...] conversion */
#define	CT_STRING	2	/* %s conversion */
#define	CT_INT		3	/* integer, i.e., strtol or strtoul */
#define	CT_FLOAT	4	/* floating, i.e., strtod */

#if 0
#define u_char unsigned char
#endif
#define u_char char
#define u_long unsigned long

#ifndef _NO_LONGLONG
typedef unsigned long long u_long_long;
#endif

/*static*/ u_char *__sccl ();

/*
 * vfscanf
 */

#define BufferEmpty (fp->_r <= 0 && __srefill_r(rptr, fp))

#ifndef _REENT_ONLY

int
_DEFUN(VFSCANF, (fp, fmt, ap), 
       register FILE *fp _AND 
       _CONST char *fmt _AND 
       va_list ap)
{
  CHECK_INIT(_REENT, fp);
  return __SVFSCANF_R (_REENT, fp, fmt, ap);
}

int
_DEFUN(__SVFSCANF, (fp, fmt0, ap),
       register FILE *fp _AND
       char _CONST *fmt0 _AND
       va_list ap)
{
  return __SVFSCANF_R (_REENT, fp, fmt0, ap);
}

#endif /* !_REENT_ONLY */

int
_DEFUN(_VFSCANF_R, (data, fp, fmt, ap),
       struct _reent *data _AND 
       register FILE *fp   _AND 
       _CONST char *fmt    _AND 
       va_list ap)
{
  CHECK_INIT(data, fp);
  return __SVFSCANF_R (data, fp, fmt, ap);
}


int
_DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap),
       struct _reent *rptr _AND
       register FILE *fp   _AND
       char _CONST *fmt0   _AND
       va_list ap)
{
  register u_char *fmt = (u_char *) fmt0;
  register int c;		/* character from format, or conversion */
  register size_t width;	/* field width, or 0 */
  register char *p;		/* points into all kinds of strings */
  register int n;		/* handy integer */
  register int flags;		/* flags as defined above */
  register char *p0;		/* saves original value of p when necessary */
  int nassigned;		/* number of fields assigned */
  int nread;			/* number of characters consumed from fp */
#ifndef _NO_POS_ARGS
  int N;			/* arg number */
  int arg_index = 0;		/* index into args processed directly */
  int numargs = 0;		/* number of varargs read */
  void *args[MAX_POS_ARGS];	/* positional args read */
  int is_pos_arg;		/* is current format positional? */
#endif
  int base = 0;			/* base argument to strtol/strtoul */
  int nbytes = 1;               /* number of bytes read from fmt string */
  wchar_t wc;                   /* wchar to use to read format string */
  wchar_t *wcp;                 /* handy wide character pointer */
  size_t mbslen;                /* length of converted multibyte sequence */
  mbstate_t state;              /* value to keep track of multibyte state */

  u_long (*ccfn) () = 0;	/* conversion function (strtol/strtoul) */
  char ccltab[256];		/* character class table for %[...] */
  char buf[BUF];		/* buffer for numeric conversions */
  char *lptr;                   /* literal pointer */

  char *cp;
  short *sp;
  int *ip;
#ifdef FLOATING_POINT
  float *flp;
  _LONG_DOUBLE *ldp;
  double *dp;
#endif
  long *lp;
#ifndef _NO_LONGLONG
  long long *llp;
#endif

  /* `basefix' is used to avoid `if' tests in the integer scanner */
  static _CONST short basefix[17] =
    {10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};

  /* Macro to support positional arguments */
#ifndef _NO_POS_ARGS
# define GET_ARG(n, ap, type)					\
  ((type) (is_pos_arg						\
	   ? (n < numargs					\
	      ? args[n]						\
	      : get_arg (n, &ap, &numargs, args))		\
	   : (arg_index++ < numargs				\
	      ? args[n]						\
	      : (numargs < MAX_POS_ARGS				\
		 ? args[numargs++] = va_arg (ap, void *)	\
		 : va_arg (ap, void *)))))
#else
# define GET_ARG(n, ap, type) (va_arg (ap, type))
#endif

  _flockfile (fp);
 
  nassigned = 0;
  nread = 0;
  for (;;)
    {
#ifndef _MB_CAPABLE
      wc = *fmt;
#else
      memset (&state, '\0', sizeof (state));
      nbytes = _mbtowc_r (rptr, &wc, fmt, MB_CUR_MAX, &state);
#endif
      fmt += nbytes;
      if (wc == 0)
	goto all_done;
      if (nbytes == 1 && isspace (wc))
	{
	  for (;;)
	    {
	      if (BufferEmpty || !isspace (*fp->_p))
		break;
	      nread++, fp->_r--, fp->_p++;
	    }
	  continue;
	}
      if (wc != '%')
	goto literal;
      width = 0;
      flags = 0;
#ifndef _NO_POS_ARGS
      N = arg_index;
      is_pos_arg = 0;
#endif

      /*
       * switch on the format.  continue if done; break once format
       * type is derived.
       */

    again:
      c = *fmt++;

      switch (c)
	{
	case '%':
	literal:
          lptr = fmt - nbytes;
          for (n = 0; n < nbytes; ++n)
            {
	      if (BufferEmpty)
	        goto input_failure;
	      if (*fp->_p != *lptr)
	        goto match_failure;
	      fp->_r--, fp->_p++;
	      nread++;
              ++lptr;
            }
	  continue;

	case '*':
	  flags |= SUPPRESS;
	  goto again;
	case 'l':
#if defined _WANT_IO_C99_FORMATS || !defined _NO_LONGLONG
	  if (*fmt == 'l')	/* Check for 'll' = long long (SUSv3) */
	    {
	      ++fmt;
	      flags |= LONGDBL;
	    }
	  else
#endif
	    flags |= LONG;
	  goto again;
	case 'L':
	  flags |= LONGDBL;
	  goto again;
	case 'h':
#ifdef _WANT_IO_C99_FORMATS
	  if (*fmt == 'h')	/* Check for 'hh' = char int (SUSv3) */
	    {
	      ++fmt;
	      flags |= CHAR;
	    }
	  else
#endif
	    flags |= SHORT;
	  goto again;
#ifdef _WANT_IO_C99_FORMATS
	case 'j': /* intmax_t */
	  if (sizeof (intmax_t) == sizeof (long))
	    flags |= LONG;
	  else
	    flags |= LONGDBL;
	  goto again;
	case 't': /* ptrdiff_t */
	  if (sizeof (ptrdiff_t) < sizeof (int))
	    /* POSIX states ptrdiff_t is 16 or more bits, as
	       is short.  */
	    flags |= SHORT;
	  else if (sizeof (ptrdiff_t) == sizeof (int))
	    /* no flag needed */;
	  else if (sizeof (ptrdiff_t) <= sizeof (long))
	    flags |= LONG;
	  else
	    /* POSIX states that at least one programming
	       environment must support ptrdiff_t no wider than
	       long, but that means other environments can
	       have ptrdiff_t as wide as long long.  */
	    flags |= LONGDBL;
	  goto again;
	case 'z': /* size_t */
	  if (sizeof (size_t) < sizeof (int))
	    /* POSIX states size_t is 16 or more bits, as is short.  */
	    flags |= SHORT;
	  else if (sizeof (size_t) == sizeof (int))
	    /* no flag needed */;
	  else if (sizeof (size_t) <= sizeof (long))
	    flags |= LONG;
	  else
	    /* POSIX states that at least one programming
	       environment must support size_t no wider than
	       long, but that means other environments can
	       have size_t as wide as long long.  */
	    flags |= LONGDBL;
	  goto again;
#endif /* _WANT_IO_C99_FORMATS */

	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
	  width = width * 10 + c - '0';
	  goto again;

#ifndef _NO_POS_ARGS
	case '$':