vfscanf.c

Newlib 嵌入式 C库 标准实现代码

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

INDEX
	vscanf
INDEX
	vfscanf
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(void *<[reent]>, const char *<[fmt]>, 
                       va_list <[list]>);
	int _vfscanf_r(void *<[reent]>, FILE *<[fp]>, const char *<[fmt]>, 
                       va_list <[list]>);
	int _vsscanf_r(void *<[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]>)
	char *<[reent]>;
	char *<[fmt]>;
	va_list <[list]>;

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

/*-
 * 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.
 */

#include <_ansi.h>
#include <reent.h>
#include <newlib.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <wchar.h>
#include <string.h>
#ifdef _HAVE_STDC
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include "local.h"

#ifndef	NO_FLOATING_POINT
#define FLOATING_POINT
#endif

#ifdef FLOATING_POINT
#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

#define _NO_LONGLONG
#if defined _WANT_IO_LONG_LONG && defined __GNUC__
# undef _NO_LONGLONG
#endif

#include "floatio.h"
#define	BUF	(MAXEXP+MAXFRACT+3)	/* 3 = sign + decimal point + NUL */
/* 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

/*
 * Flags used during conversion.
 */

#define	LONG		0x01	/* l: long or double */
#define	LONGDBL		0x02	/* L: long double or long long */
#define	SHORT		0x04	/* h: short */
#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 */

#define	VECTOR		0x2000	/* v: vector */
#define	FIXEDPOINT	0x4000	/* r/R: fixed-point */
#define	SIGNED  	0x8000	/* r: signed fixed-point */

/*
 * 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

typedef union
{
  char c[16] __attribute__ ((__aligned__ (16)));
  short h[8];
  long l[4];
  int i[4];
  float f[4];
} vec_union;

/*static*/ u_char *__sccl ();

/*
 * vfscanf
 */

#define BufferEmpty (fp->_r <= 0 && __srefill(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
__svfscanf (fp, fmt0, ap)
     register FILE *fp;
     char _CONST *fmt0;
     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)
{
  return __svfscanf_r (data, fp, fmt, ap);
}


int
__svfscanf_r (rptr, fp, fmt0, ap)
     struct _reent *rptr;
     register FILE *fp;
     char _CONST *fmt0;
     va_list ap;
{
  register u_char *fmt = (u_char *) fmt0;
  register int c;		/* character from format, or conversion */
  register int type;		/* conversion type */
  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 orig_flags;               /* saved flags used when processing vector */
  int int_width;                /* tmp area to store width when processing int */
  int nassigned;		/* number of fields assigned */
  int nread;			/* number of characters consumed from fp */
  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 */
  char vec_sep;                 /* vector separator char */
  char last_space_char;         /* last white-space char eaten - needed for vec support */
  int vec_read_count;           /* number of vector items to read separately */
  int looped;                   /* has vector processing looped */
  u_long (*ccfn) () = 0;	/* conversion function (strtol/strtoul) */
  char ccltab[256];		/* character class table for %[...] */
  char buf[BUF];		/* buffer for numeric conversions */
  vec_union vec_buf;
  char *lptr;                   /* literal pointer */
#ifdef _MB_CAPABLE
  mbstate_t state;                /* value to keep track of multibyte state */
#endif

  char *ch_dest;
  short *sp;
  int *ip;
  float *flp;
  _LONG_DOUBLE *ldp;
  double *dp;
  long *lp;
#ifndef _NO_LONGLONG
  long long *llp;
#else
	u_long _uquad;
#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};

  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)
	return nassigned;
      if (nbytes == 1 && isspace (wc))
	{
	  for (;;)
	    {
	      if (BufferEmpty)
		return nassigned;
	      if (!isspace (*fp->_p))
		break;
	      nread++, fp->_r--, fp->_p++;
	    }
	  continue;
	}
      if (wc != '%')
	goto literal;
      width = 0;
      flags = 0;
      vec_sep = ' ';
      vec_read_count = 0;
      looped = 0;

      /*
       * 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 ',':
	case ';':
	case ':':
	case '_':
	  if (flags == SUPPRESS || flags == 0)
	    vec_sep = c;
	  goto again;
	case 'l':
	  if (flags & SHORT)
	    continue; /* invalid format, don't process any further */
	  if (flags & LONG)
	    {
	      flags &= ~LONG;
	      flags &= ~VECTOR;
	      flags |= LONGDBL;
	    }
	  else
	    {
	      flags |= LONG;
	      if (flags & VECTOR)
		vec_read_count = 4;
	    }
	  goto again;
	case 'L':
	  flags |= LONGDBL;
	  flags &= ~VECTOR;
	  goto again;
	case 'h':
	  flags |= SHORT;
	  if (flags & LONG)
	    continue;  /* invalid format, don't process any further */
	  if (flags & VECTOR)
	    vec_read_count = 8;
	  goto again;
#ifdef __ALTIVEC__
	case 'v':
	  flags |= VECTOR;
	  vec_read_count = (flags & SHORT) ? 8 : ((flags & LONG) ? 4 : 16);
	  goto again;
#endif
	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;

	  /*
	   * Conversions. Those marked `compat' are for
	   * 4.[123]BSD compatibility.
	   *
	   * (According to ANSI, E and X formats are supposed to
	   * the same as e and x.  Sorry about that.)
	   */

	case 'D':		/* compat */
	  flags |= LONG;
	  /* FALLTHROUGH */
	case 'd':
	  type = CT_INT;
	  ccfn = (u_long (*)())_strtol_r;
	  base = 10;
	  break;

	case 'i':
	  type = CT_INT;
	  ccfn = (u_long (*)())_strtol_r;
	  base = 0;
	  break;

	case 'O':		/* compat */
	  flags |= LONG;
	  /* FALLTHROUGH */
	case 'o':
	  type = CT_INT;
	  ccfn = _strtoul_r;
	  base = 8;
	  break;

	case 'u':
	  type = CT_INT;
	  ccfn = _strtoul_r;
	  base = 10;
	  break;

	case 'X':		/* compat   XXX */
	case 'x':
	  flags |= PFXOK;	/* enable 0x prefixing */
	  type = CT_INT;
	  ccfn = _strtoul_r;
	  base = 16;
	  break;

#ifdef FLOATING_POINT
	case 'E':		/* compat   XXX */
	case 'G':		/* compat   XXX */
/* ANSI says that E,G and X behave the same way as e,g,x */
	  /* FALLTHROUGH */
	case 'e':
	case 'f':
	case 'g':
	  type = CT_FLOAT;
	  if (flags & VECTOR)
	    vec_read_count = 4;
	  break;
       
# ifdef __SPE__
	  /* treat fixed-point like %f floating point */
        case 'r':
	  flags |= SIGNED;
	  /* fallthrough */
        case 'R':
          flags |= FIXEDPOINT;
	  type = CT_FLOAT;
          break;
# endif
#endif

	case 's':
	  flags &= ~VECTOR;
	  type = CT_STRING;
	  break;

	case '[':
	  fmt = __sccl (ccltab, fmt);
	  flags |= NOSKIP;
	  flags &= ~VECTOR;
	  type = CT_CCL;
	  break;

	case 'c':
	  flags |= NOSKIP;
	  type = CT_CHAR;
	  if (flags & VECTOR)
	    {
	      /* not allowed to have h or l with c specifier */
	      if (flags & (LONG | SHORT))
		continue;  /* invalid format don't process any further */
	      width = 0;
	      vec_read_count = 16;
	    }
	  break;

	case 'p':		/* pointer format is like hex */
	  flags |= POINTER | PFXOK;
	  type = CT_INT;
	  ccfn = _strtoul_r;
	  base = 16;
	  break;

	case 'n':
	  if (flags & SUPPRESS)	/* ??? */
	    continue;
	  flags &= ~VECTOR;
	  if (flags & SHORT)
	    {
	      sp = va_arg (ap, short *);
	      *sp = nread;
	    }
	  else if (flags & LONG)
	    {
	      lp = va_arg (ap, long *);
	      *lp = nread;
	    }
#ifndef _NO_LONGLONG
	  else if (flags & LONGDBL)
	    {
	      llp = va_arg (ap, long long*);
	      *llp = nread;
	    }
#endif
	  else
	    {
	      ip = va_arg (ap, int *);
	      *ip = nread;
	    }
	  continue;

	  /*
	   * Disgusting backwards compatibility hacks.	XXX
	   */
	case '\0':		/* compat */
	  return EOF;

	default:		/* compat */
	  if (isupper (c))
	    flags |= LONG;
	  type = CT_INT;
	  ccfn = (u_long (*)())_strtol_r;
	  base = 10;
	  break;
	}

    process:
      /*
       * We have a conversion that requires input.
       */
      if (BufferEmpty)
	goto input_failure;

      /*
       * Consume leading white space, except for formats that
       * suppress this.
       */
      last_space_char = '\0';

      if ((flags & NOSKIP) == 0)
	{
	  while (isspace (*fp->_p))
	    {
	      last_space_char = *fp->_p;
	      nread++;
	      if (--fp->_r > 0)
		fp->_p++;
	      else
#ifndef CYGNUS_NEC
	      if (__srefill (fp))
#endif
		goto input_failure;
	    }
	  /*
	   * Note that there is at least one character in the
	   * buffer, so conversions that do not set NOSKIP ca
	   * no longer result in an input failure.
	   */
	}

      /* for vector formats process separator characters after first loop */
      if (looped && (flags & VECTOR))
	{
	  flags = orig_flags; 
	  /* all formats other than default char have a separator char */
	  if (vec_sep != ' ' || type != CT_CHAR)
	    {
	      if (vec_sep == ' ' && last_space_char != ' ' ||
		  vec_sep != ' ' && *fp->_p != vec_sep)
		goto match_failure;
	      if (vec_sep != ' ')
		{
		  nread++;
		  if (--fp->_r > 0)
		    fp->_p++;
		  else
#ifndef CYGNUS_NEC
		    if (__srefill (fp))
#endif
		      goto input_failure;
		}
	    }
	  /* after eating the separator char, we must eat any white-space
	     after the separator char that precedes the data to convert */
	  if ((flags & NOSKIP) == 0)
	    {
	      while (isspace (*fp->_p))
		{
		  last_space_char = *fp->_p;
		  nread++;
		  if (--fp->_r > 0)
		    fp->_p++;
		  else
#ifndef CYGNUS_NEC