sources/android/support/src/wcstox/intscan.c

// ----------------------------------------------------------------------
// Copyright © 2005-2014 Rich Felker, et al.
// Copyright 2014 The Android Open Source Project.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// ----------------------------------------------------------------------

#include <limits.h>
#include <errno.h>
#include <ctype.h>
#include "shgetc.h"

// ANDROID: Redefine FILE to use our custom stream abstraction.
#undef FILE
#define FILE struct fake_file_t

/* Lookup table for digit values. -1==255>=36 -> invalid */
static const unsigned char table[] = { -1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1,
-1,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
25,26,27,28,29,30,31,32,33,34,35,-1,-1,-1,-1,-1,
-1,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
25,26,27,28,29,30,31,32,33,34,35,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
};

unsigned long long __intscan(FILE *f, unsigned base, int pok, unsigned long long lim)
{
	const unsigned char *val = table+1;
	int c, neg=0;
	unsigned x;
	unsigned long long y;
	if (base > 36) {
		errno = EINVAL;
		return 0;
	}
	while (isspace((c=shgetc(f))));
	if (c=='+' || c=='-') {
		neg = -(c=='-');
		c = shgetc(f);
	}
	if ((base == 0 || base == 16) && c=='0') {
		c = shgetc(f);
		if ((c|32)=='x') {
			c = shgetc(f);
			if (val[c]>=16) {
				shunget(f);
				if (pok) shunget(f);
				else shlim(f, 0);
				return 0;
			}
			base = 16;
		} else if (base == 0) {
			base = 8;
		}
	} else {
		if (base == 0) base = 10;
		if (val[c] >= base) {
			shunget(f);
			shlim(f, 0);
			errno = EINVAL;
			return 0;
		}
	}
	if (base == 10) {
		for (x=0; c-'0'<10U && x<=UINT_MAX/10-1; c=shgetc(f))
			x = x*10 + (c-'0');
		for (y=x; c-'0'<10U && y<=ULLONG_MAX/10 && 10*y<=ULLONG_MAX-(c-'0'); c=shgetc(f))
			y = y*10 + (c-'0');
		if (c-'0'>=10U) goto done;
	} else if (!(base & base-1)) {
		int bs = "\0\1\2\4\7\3\6\5"[(0x17*base)>>5&7];
		for (x=0; val[c]<base && x<=UINT_MAX/32; c=shgetc(f))
			x = x<<bs | val[c];
		for (y=x; val[c]<base && y<=ULLONG_MAX>>bs; c=shgetc(f))
			y = y<<bs | val[c];
	} else {
		for (x=0; val[c]<base && x<=UINT_MAX/36-1; c=shgetc(f))
			x = x*base + val[c];
		for (y=x; val[c]<base && y<=ULLONG_MAX/base && base*y<=ULLONG_MAX-val[c]; c=shgetc(f))
			y = y*base + val[c];
	}
	if (val[c]<base) {
		for (; val[c]<base; c=shgetc(f));
		errno = ERANGE;
		y = lim;
	}
done:
	shunget(f);
	if (y>=lim) {
		if (!(lim&1) && !neg) {
			errno = ERANGE;
			return lim-1;
		} else if (y>lim) {
			errno = ERANGE;
			return lim;
		}
	}
	return (y^neg)-neg;
}