File: [local] / OpenXM_contrib / gmp / scanf / Attic / doscan.c (download)
Revision 1.1.1.1 (vendor branch), Mon Aug 25 16:06:36 2003 UTC (20 years, 10 months ago) by ohara
Branch: GMP
CVS Tags: VERSION_4_1_2, RELEASE_1_2_3, RELEASE_1_2_2_KNOPPIX_b, RELEASE_1_2_2_KNOPPIX Changes since 1.1: +0 -0
lines
Import gmp 4.1.2
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/* __gmp_doscan -- formatted input internals.
THE FUNCTIONS IN THIS FILE ARE FOR INTERNAL USE ONLY. THEY'RE ALMOST
CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN
FUTURE GNU MP RELEASES.
Copyright 2001, 2002 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP 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 MP 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 MP Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include "config.h"
#if HAVE_STDARG
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include <ctype.h>
#include <stddef.h> /* for ptrdiff_t */
#include <stdio.h>
#include <string.h>
#if HAVE_LOCALE_H
#include <locale.h> /* for localeconv */
#endif
#if HAVE_INTTYPES_H
# include <inttypes.h> /* for intmax_t */
#else
# if HAVE_STDINT_H
# include <stdint.h>
# endif
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h> /* for quad_t */
#endif
#include "gmp.h"
#include "gmp-impl.h"
/* Change this to "#define TRACE(x) x" for some traces. */
#define TRACE(x)
/* It's necessary to parse up the string to recognise the GMP extra types F,
Q and Z. Other types and conversions are passed across to the standard
sscanf or fscanf via funs->scan, for ease of implemenation. This is
essential in the case of something like glibc %p where the pointer format
isn't actually documented.
Because funs->scan doesn't get the whole input it can't put the right
values in for %n, so that's handled in __gmp_doscan. Neither sscanf nor
fscanf directly indicate how many characters were read, so an extra %n is
appended to each run for that. For fscanf this merely supports our %n
output, but for sscanf it lets funs->step move us along the input string.
Whitespace and literal matches in the format string, including %%, are
handled directly within __gmp_doscan. This is reasonably efficient, and
avoids some suspicious behaviour observed in various system libc's.
GLIBC 2.2.4 for instance returns 0 on sscanf(" "," x") or on sscanf(" ",
" x%d",&n), whereas we think they should return EOF, since end-of-string
is reached when a match of "x" is required.
For standard % conversions, funs->scan is called once for each
conversion. If we had vfscanf and vsscanf and could rely on their fixed
text matching behaviour then we could call them with multiple consecutive
standard conversions. But plain fscanf and sscanf work fine, and parsing
one field at a time shouldn't be too much of a slowdown.
gmpscan reads a gmp type. It's only used from one place, but is a
separate subroutine to avoid a big chunk of complicated code in the
middle of __gmp_doscan. Within gmpscan a couple of loopbacks make it
possible to share code for parsing integers, rationals and floats.
In gmpscan normally one char of lookahead is maintained, but when width
is reached that stops, on the principle that an fgetc/ungetc of a char
past where we're told to stop would be undesirable. "chars" is how many
characters have been read so far, including the current c. When
chars==width and another character is desired then a jump is done to the
"convert" stage. c is invalid and mustn't be unget'ed in this case;
chars is set to width+1 to indicate that.
gmpscan normally returns the number of characters read. -1 means an
invalid field, like a "-" or "+" alone. -2 means EOF reached before any
matching characters were read.
Consideration was given to using a separate code for gmp_fscanf and
gmp_sscanf. The sscanf case could zip across a string making literal
matches or recognising digits in gmpscan, rather than making a function
call fun->get per character. The fscanf could use getc rather than fgetc
too, which might help those systems where getc is a macro or otherwise
inlined. But none of this scanning and converting will be particularly
fast, so the two are done together to keep it a bit simpler for now.
Enhancements:
A way to read the GLIBC printf %a format that we support in gmp_printf
would be good. That would probably be good for plain GLIBC scanf too, so
perhaps we can simply follow its lead if it gets such a feature in the
future. */
struct gmp_doscan_params_t {
int base;
int ignore;
char type;
int width;
};
#define GET(c) \
do { \
ASSERT (chars <= width); \
chars++; \
if (chars > width) \
goto convert; \
(c) = (*funs->get) (data); \
} while (0)
/* store into "s", extending if necessary */
#define STORE(c) \
do { \
ASSERT (s_upto <= s_alloc); \
if (s_upto >= s_alloc) \
{ \
size_t s_alloc_new = s_alloc + S_ALLOC_STEP; \
s = __GMP_REALLOCATE_FUNC_TYPE (s, s_alloc, s_alloc_new, char); \
s_alloc = s_alloc_new; \
} \
s[s_upto++] = c; \
} while (0)
#define S_ALLOC_STEP 512
static int
gmpscan (const struct gmp_doscan_funs_t *funs, void *data,
const struct gmp_doscan_params_t *p, void *dst)
{
int chars, c, base, first, width, seen_point, seen_digit;
size_t s_upto, s_alloc;
char *s;
int invalid = 0;
TRACE (printf ("gmpscan\n"));
ASSERT (p->type == 'F' || p->type == 'Q' || p->type == 'Z');
c = (*funs->get) (data);
if (c == EOF)
return -2;
chars = 1;
first = 1;
seen_point = 0;
seen_digit = 0;
width = (p->width == 0 ? INT_MAX-1 : p->width);
base = p->base;
s_alloc = S_ALLOC_STEP;
s = __GMP_ALLOCATE_FUNC_TYPE (s_alloc, char);
s_upto = 0;
another:
if (c == '-')
{
STORE (c);
goto get_for_sign;
}
else if (c == '+')
{
/* don't store '+', it's not accepted by mpz_set_str etc */
get_for_sign:
GET (c);
}
if (base == 0)
{
base = 10;
if (c == '0')
{
seen_digit = 1;
base = 8;
STORE (c);
GET (c);
if (c == 'x' || c == 'X')
{
base = 16;
store_get_digits:
STORE (c);
GET (c);
}
}
}
digits:
for (;;)
{
if (base == 16)
{
if (! (isascii (c) && isxdigit (c)))
break;
}
else
{
if (! (isascii (c) && isdigit (c)))
break;
if (base == 8 && (c == '8' || c == '9'))
break;
}
seen_digit = 1;
STORE (c);
GET (c);
}
if (first)
{
/* decimal point */
if (p->type == 'F' && ! seen_point)
{
#if HAVE_LOCALECONV
/* For a multi-character decimal point, if the first character is
present then all of it must be, otherwise the input is
considered invalid. */
const char *point;
int pc;
point = localeconv()->decimal_point;
pc = *point++;
if (c == pc)
{
for (;;)
{
STORE (c);
GET (c);
pc = *point++;
if (pc == '\0')
break;
if (c != pc)
goto invalid;
}
seen_point = 1;
goto digits;
}
#else
if (c == '.')
{
seen_point = 1;
goto store_get_digits;
}
#endif
}
/* exponent */
if (p->type == 'F' && (c == 'e' || c == 'E'))
{
/* must have at least one digit in the mantissa, just an exponent
is not good enough */
if (! seen_digit)
goto invalid;
exponent:
first = 0;
STORE (c);
GET (c);
goto another;
}
/* denominator */
if (p->type == 'Q' && c == '/')
{
/* must have at least one digit in the numerator */
if (! seen_digit)
goto invalid;
/* now look for at least one digit in the denominator */
seen_digit = 0;
/* allow the base to be redetermined for "%i" */
base = p->base;
goto exponent;
}
}
convert:
if (! seen_digit)
{
invalid:
invalid = 1;
goto done;
}
if (! p->ignore)
{
STORE ('\0');
TRACE (printf (" convert \"%s\"\n", s));
/* We ought to have parsed out a valid string above, so just test
mpz_set_str etc with an ASSERT. */
switch (p->type) {
case 'F':
ASSERT (p->base == 10);
ASSERT_NOCARRY (mpf_set_str ((mpf_ptr) dst, s, 10));
break;
case 'Q':
ASSERT_NOCARRY (mpq_set_str ((mpq_ptr) dst, s, p->base));
break;
case 'Z':
ASSERT_NOCARRY (mpz_set_str ((mpz_ptr) dst, s, p->base));
break;
default:
ASSERT (0);
/*FALLTHRU*/
break;
}
}
done:
ASSERT (chars <= width+1);
if (chars != width+1)
{
(*funs->unget) (c, data);
TRACE (printf (" ungetc %d, to give %d chars\n", c, chars-1));
}
chars--;
(*__gmp_free_func) (s, s_alloc);
if (invalid)
{
TRACE (printf (" invalid\n"));
return -1;
}
TRACE (printf (" return %d chars (cf width %d)\n", chars, width));
return chars;
}
/* Read and discard whitespace, if any. Return number of chars skipped.
Whitespace skipping never provokes the EOF return from __gmp_doscan, so
it's not necessary to watch for EOF from funs->get, */
static int
skip_white (const struct gmp_doscan_funs_t *funs, void *data)
{
int c;
int ret = 0;
do
{
c = (funs->get) (data);
ret++;
}
while (isascii (c) && isspace (c));
(funs->unget) (c, data);
ret--;
TRACE (printf (" skip white %d\n", ret));
return ret;
}
int
__gmp_doscan (const struct gmp_doscan_funs_t *funs, void *data,
const char *orig_fmt, va_list orig_ap)
{
struct gmp_doscan_params_t param;
va_list ap;
char *alloc_fmt;
const char *fmt, *this_fmt, *end_fmt;
size_t orig_fmt_len, alloc_fmt_size, len;
int new_fields, new_chars;
char fchar;
int fields = 0;
int chars = 0;
TRACE (printf ("__gmp_doscan \"%s\"\n", orig_fmt);
if (funs->scan == (gmp_doscan_scan_t) sscanf)
printf (" s=\"%s\"\n", (const char *) data));
/* Don't modify orig_ap, if va_list is actually an array and hence call by
reference. It could be argued that it'd be more efficient to leave
callers to make a copy if they care, but doing so here is going to be a
very small part of the total work, and we may as well keep applications
out of trouble. */
va_copy (ap, orig_ap);
/* Parts of the format string are going to be copied so that a " %n" can
be appended. alloc_fmt is some space for that. orig_fmt_len+4 will be
needed if fmt consists of a single "%" specifier, but otherwise is an
overestimate. We're not going to be very fast here, so use
__gmp_allocate_func rather than TMP_ALLOC. */
orig_fmt_len = strlen (orig_fmt);
alloc_fmt_size = orig_fmt_len + 4;
alloc_fmt = __GMP_ALLOCATE_FUNC_TYPE (alloc_fmt_size, char);
fmt = orig_fmt;
end_fmt = orig_fmt + orig_fmt_len;
for (;;)
{
next:
fchar = *fmt++;
if (fchar == '\0')
break;
if (isascii (fchar) && isspace (fchar))
{
chars += skip_white (funs, data);
continue;
}
if (fchar != '%')
{
int c;
literal:
c = (funs->get) (data);
if (c != fchar)
{
(funs->unget) (c, data);
if (c == EOF)
{
eof_no_match:
if (fields == 0)
fields = EOF;
}
goto done;
}
chars++;
continue;
}
param.type = '\0';
param.base = 10;
param.ignore = 0;
param.width = 0;
this_fmt = fmt-1;
TRACE (printf (" this_fmt \"%s\"\n", this_fmt));
for (;;)
{
ASSERT (fmt <= end_fmt);
fchar = *fmt++;
switch (fchar) {
case '\0': /* unterminated % sequence */
ASSERT (0);
goto done;
case '%': /* literal % */
goto literal;
case '[': /* character range */
fchar = *fmt++;
if (fchar == '^')
fchar = *fmt++;
/* ']' allowed as the first char (possibly after '^') */
if (fchar == ']')
fchar = *fmt++;
for (;;)
{
ASSERT (fmt <= end_fmt);
if (fchar == '\0')
{
/* unterminated % sequence */
ASSERT (0);
goto done;
}
if (fchar == ']')
break;
fchar = *fmt++;
}
/*FALLTHRU*/
case 'c': /* characters */
case 's': /* string of non-whitespace */
case 'p': /* pointer */
libc_type:
len = fmt - this_fmt;
memcpy (alloc_fmt, this_fmt, len);
alloc_fmt[len++] = '%';
alloc_fmt[len++] = 'n';
alloc_fmt[len] = '\0';
TRACE (printf (" scan \"%s\"\n", alloc_fmt);
if (funs->scan == (gmp_doscan_scan_t) sscanf)
printf (" s=\"%s\"\n", (const char *) data));
new_chars = -1;
if (param.ignore)
{
new_fields = (*funs->scan) (data, alloc_fmt, &new_chars);
ASSERT (new_fields == 0 || new_fields == EOF);
}
else
{
new_fields = (*funs->scan) (data, alloc_fmt,
va_arg (ap, void *), &new_chars);
ASSERT (new_fields==0 || new_fields==1 || new_fields==EOF);
if (new_fields == 0)
goto done; /* invalid input */
if (new_fields == 1)
ASSERT (new_chars != -1);
}
TRACE (printf (" new_fields %d new_chars %d\n",
new_fields, new_chars));
if (new_fields == -1)
goto eof_no_match; /* EOF before anything matched */
/* Wnder param.ignore, when new_fields==0 we don't know if
it's a successful match or an invalid field. new_chars
won't have been assigned if it was an invalid field. */
if (new_chars == -1)
goto done; /* invalid input */
chars += new_chars;
(*funs->step) (data, new_chars);
increment_fields:
if (! param.ignore)
fields++;
goto next;
case 'd': /* decimal */
case 'e': /* float */
case 'E': /* float */
case 'f': /* float */
case 'g': /* float */
case 'G': /* float */
case 'u': /* decimal */
numeric:
if (param.type != 'F' && param.type != 'Q' && param.type != 'Z')
goto libc_type;
chars += skip_white (funs, data);
new_chars = gmpscan (funs, data, ¶m,
param.ignore ? NULL : va_arg (ap, void*));
if (new_chars == -2)
goto eof_no_match;
if (new_chars == -1)
goto done;
ASSERT (new_chars >= 0);
chars += new_chars;
goto increment_fields;
case 'a': /* glibc allocate string */
case '\'': /* glibc digit groupings */
break;
case 'F': /* mpf_t */
case 'j': /* intmax_t */
case 'L': /* long long */
case 'q': /* quad_t */
case 'Q': /* mpq_t */
case 't': /* ptrdiff_t */
case 'z': /* size_t */
case 'Z': /* mpz_t */
set_type:
param.type = fchar;
break;
case 'h': /* short or char */
if (param.type != 'h')
goto set_type;
param.type = 'H'; /* internal code for "hh" */
break;
case 'i':
param.base = 0;
goto numeric;
case 'l': /* long, long long, double or long double */
if (param.type != 'l')
goto set_type;
param.type = 'L'; /* "ll" means "L" */
break;
case 'n':
if (! param.ignore)
{
void *p;
p = va_arg (ap, void *);
TRACE (printf (" store %%n to %p\n", p));
switch (param.type) {
case '\0': * (int *) p = chars; break;
case 'F': mpf_set_si ((mpf_ptr) p, (long) chars); break;
case 'H': * (char *) p = chars; break;
case 'h': * (short *) p = chars; break;
#if HAVE_INTMAX_T
case 'j': * (intmax_t *) p = chars; break;
#else
case 'j': ASSERT_FAIL (intmax_t not available); break;
#endif
case 'l': * (long *) p = chars; break;
#if HAVE_QUAD_T && HAVE_LONG_LONG
case 'q':
ASSERT_ALWAYS (sizeof (quad_t) == sizeof (long long));
/*FALLTHRU*/
#else
case 'q': ASSERT_FAIL (quad_t not available); break;
#endif
#if HAVE_LONG_LONG
case 'L': * (long long *) p = chars; break;
#else
case 'L': ASSERT_FAIL (long long not available); break;
#endif
case 'Q': mpq_set_si ((mpq_ptr) p, (long) chars, 1L); break;
#if HAVE_PTRDIFF_T
case 't': * (ptrdiff_t *) p = chars; break;
#else
case 't': ASSERT_FAIL (ptrdiff_t not available); break;
#endif
case 'z': * (size_t *) p = chars; break;
case 'Z': mpz_set_si ((mpz_ptr) p, (long) chars); break;
default: ASSERT (0); break;
}
}
goto next;
case 'o':
param.base = 8;
goto numeric;
case 'x':
case 'X':
param.base = 16;
goto numeric;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
param.width = 0;
do {
param.width = param.width * 10 + (fchar-'0');
fchar = *fmt++;
} while (isascii (fchar) && isdigit (fchar));
fmt--; /* unget the non-digit */
break;
case '*':
param.ignore = 1;
break;
default:
/* something invalid in a % sequence */
ASSERT (0);
goto next;
}
}
}
done:
(*__gmp_free_func) (alloc_fmt, alloc_fmt_size);
return fields;
}