platform_bionic/libc/stdio/vfwscanf.cpp
zijunzhao cc475cf28d Implement C23 scanf 'wf' length modifiers
wfN: Specifies that a following b, d, i, o, u, x, or X conversion specifier applies to a fastest minimum-width integer argument with a specific width where N is a positive decimal integer with no leading zeros (the argument will have been promoted according to the integer promotions, but its value shall be converted to the unpromoted type); or that a following n conversion specifier applies to a pointer to a fastest minimum-width integer type argument with a width of N bits. All fastest minimum-width integer types (7.22.1.3) defined in the header <stdint.h> shall be supported. Other supported values of N are implementation-defined.

Bug: b/271903607
Test: adb shell
Change-Id: Iaa1f6d87251144de0b763672ca93f23272880ad1
2023-06-14 17:15:58 +00:00

603 lines
18 KiB
C++

/* $OpenBSD: vfwscanf.c,v 1.4 2014/03/19 05:17:01 guenther Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "scanf_common.h"
// An interpretive version of __sccl from vfscanf.c --- a table of all wchar_t values would
// be a little too expensive, and some kind of compressed version isn't worth the trouble.
static inline bool in_ccl(wchar_t wc, const wchar_t* ccl) {
// Is this a negated set?
bool member_result = true;
if (*ccl == '^') {
member_result = false;
++ccl;
}
// The first character may be ']' or '-' without being special.
if (*ccl == '-' || *ccl == ']') {
// A literal match?
if (*ccl == wc) return member_result;
++ccl;
}
while (*ccl && *ccl != ']') {
// The last character may be '-' without being special.
if (*ccl == '-' && ccl[1] != '\0' && ccl[1] != ']') {
wchar_t first = *(ccl - 1);
wchar_t last = *(ccl + 1);
if (first <= last) {
// In the range?
if (wc >= first && wc <= last) return member_result;
ccl += 2;
continue;
}
// A '-' is not considered to be part of a range if the character after
// is not greater than the character before, so fall through...
}
// A literal match?
if (*ccl == wc) return member_result;
++ccl;
}
return !member_result;
}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wframe-larger-than="
/*
* vfwscanf
*/
int __vfwscanf(FILE* __restrict fp, const wchar_t* __restrict fmt, __va_list ap) {
wint_t c; /* character from format, or conversion */
size_t width; /* field width, or 0 */
wchar_t* p; /* points into all kinds of strings */
int n; /* handy integer */
int flags; /* flags as defined above */
wchar_t* p0; /* saves original value of p when necessary */
int nassigned; /* number of fields assigned */
int nconversions; /* number of conversions */
int nread; /* number of characters consumed from fp */
int base; /* base argument to strtoimax/strtouimax */
wchar_t buf[BUF]; /* buffer for numeric conversions */
const wchar_t* ccl;
wint_t wi; /* handy wint_t */
char* mbp; /* multibyte string pointer for %c %s %[ */
size_t nconv; /* number of bytes in mb. conversion */
char mbbuf[MB_LEN_MAX]; /* temporary mb. character buffer */
mbstate_t mbs;
_SET_ORIENTATION(fp, ORIENT_CHARS);
nassigned = 0;
nconversions = 0;
nread = 0;
base = 0; /* XXX just to keep gcc happy */
for (;;) {
c = *fmt++;
if (c == 0) {
return (nassigned);
}
if (iswspace(c)) {
while ((c = __fgetwc_unlock(fp)) != WEOF && iswspace(c))
;
if (c != WEOF) __ungetwc(c, fp);
continue;
}
if (c != '%') goto literal;
width = 0;
flags = 0;
/*
* switch on the format. continue if done;
* break once format type is derived.
*/
again:
c = *fmt++;
reswitch:
switch (c) {
case '%':
literal:
if ((wi = __fgetwc_unlock(fp)) == WEOF) goto input_failure;
if (wi != c) {
__ungetwc(wi, fp);
goto match_failure;
}
nread++;
continue;
case '*':
flags |= SUPPRESS;
goto again;
case 'j':
flags |= MAXINT;
goto again;
case 'L':
flags |= LONGDBL;
goto again;
case 'h':
if (*fmt == 'h') {
fmt++;
flags |= SHORTSHORT;
} else {
flags |= SHORT;
}
goto again;
case 'l':
if (*fmt == 'l') {
fmt++;
flags |= LLONG;
} else {
flags |= LONG;
}
goto again;
case 'q':
flags |= LLONG; /* deprecated */
goto again;
case 't':
flags |= PTRINT;
goto again;
case 'z':
flags |= SIZEINT;
goto again;
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.
*/
case 'b':
c = CT_INT;
base = 2;
flags |= PFBOK; /* enable 0b prefixing */
break;
case 'D': /* compat */
flags |= LONG;
__BIONIC_FALLTHROUGH;
case 'd':
c = CT_INT;
base = 10;
break;
case 'i':
c = CT_INT;
base = 0;
break;
case 'O': /* compat */
flags |= LONG;
__BIONIC_FALLTHROUGH;
case 'o':
c = CT_INT;
flags |= UNSIGNED;
base = 8;
break;
case 'u':
c = CT_INT;
flags |= UNSIGNED;
base = 10;
break;
case 'w': {
int size = 0;
bool fast = false;
c = *fmt++;
if (c == 'f') {
fast = true;
c = *fmt++;
}
while (is_digit(c)) {
APPEND_DIGIT(size, c);
c = *fmt++;
}
flags |= w_to_flag(size, fast);
goto reswitch;
}
case 'X':
case 'x':
flags |= PFXOK; /* enable 0x prefixing */
c = CT_INT;
flags |= UNSIGNED;
base = 16;
break;
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G':
case 'a':
case 'A':
c = CT_FLOAT;
break;
case 's':
c = CT_STRING;
break;
case '[':
ccl = fmt;
if (*fmt == '^') fmt++;
if (*fmt == ']') fmt++;
while (*fmt != '\0' && *fmt != ']') fmt++;
fmt++;
flags |= NOSKIP;
c = CT_CCL;
break;
case 'c':
flags |= NOSKIP;
c = CT_CHAR;
break;
case 'p': /* pointer format is like hex */
flags |= POINTER | PFXOK;
c = CT_INT;
flags |= UNSIGNED;
base = 16;
break;
case 'n':
nconversions++;
if (flags & SUPPRESS) continue;
if (flags & SHORTSHORT)
*va_arg(ap, signed char*) = nread;
else if (flags & SHORT)
*va_arg(ap, short*) = nread;
else if (flags & LONG)
*va_arg(ap, long*) = nread;
else if (flags & SIZEINT)
*va_arg(ap, ssize_t*) = nread;
else if (flags & PTRINT)
*va_arg(ap, ptrdiff_t*) = nread;
else if (flags & LLONG)
*va_arg(ap, long long*) = nread;
else if (flags & MAXINT)
*va_arg(ap, intmax_t*) = nread;
else
*va_arg(ap, int*) = nread;
continue;
/*
* Disgusting backwards compatibility hacks. XXX
*/
case '\0': /* compat */
return (EOF);
default: /* compat */
if (iswupper(c)) flags |= LONG;
c = CT_INT;
base = 10;
break;
}
/*
* Consume leading white space, except for formats
* that suppress this.
*/
if ((flags & NOSKIP) == 0) {
while ((wi = __fgetwc_unlock(fp)) != WEOF && iswspace(wi)) nread++;
if (wi == WEOF) goto input_failure;
__ungetwc(wi, fp);
}
/*
* Do the conversion.
*/
switch (c) {
case CT_CHAR:
/* scan arbitrary characters (sets NOSKIP) */
if (width == 0) width = 1;
if (flags & LONG) {
if (!(flags & SUPPRESS)) p = va_arg(ap, wchar_t*);
n = 0;
while (width-- != 0 && (wi = __fgetwc_unlock(fp)) != WEOF) {
if (!(flags & SUPPRESS)) *p++ = (wchar_t)wi;
n++;
}
if (n == 0) goto input_failure;
nread += n;
if (!(flags & SUPPRESS)) nassigned++;
} else {
if (!(flags & SUPPRESS)) mbp = va_arg(ap, char*);
n = 0;
memset(&mbs, 0, sizeof(mbs));
while (width != 0 && (wi = __fgetwc_unlock(fp)) != WEOF) {
if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) {
nconv = wcrtomb(mbp, wi, &mbs);
if (nconv == (size_t)-1) goto input_failure;
} else {
nconv = wcrtomb(mbbuf, wi, &mbs);
if (nconv == (size_t)-1) goto input_failure;
if (nconv > width) {
__ungetwc(wi, fp);
break;
}
if (!(flags & SUPPRESS)) memcpy(mbp, mbbuf, nconv);
}
if (!(flags & SUPPRESS)) mbp += nconv;
width -= nconv;
n++;
}
if (n == 0) goto input_failure;
nread += n;
if (!(flags & SUPPRESS)) nassigned++;
}
nconversions++;
break;
case CT_CCL:
case CT_STRING:
// CT_CCL: scan a (nonempty) character class (sets NOSKIP).
// CT_STRING: like CCL, but zero-length string OK, & no NOSKIP.
if (width == 0) width = (size_t)~0; // 'infinity'.
if ((flags & SUPPRESS) && (flags & LONG)) {
n = 0;
while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && ((c == CT_CCL && in_ccl(wi, ccl)) || (c == CT_STRING && !iswspace(wi)))) n++;
if (wi != WEOF) __ungetwc(wi, fp);
} else if (flags & LONG) {
p0 = p = va_arg(ap, wchar_t*);
while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && ((c == CT_CCL && in_ccl(wi, ccl)) || (c == CT_STRING && !iswspace(wi)))) {
*p++ = (wchar_t)wi;
}
if (wi != WEOF) __ungetwc(wi, fp);
n = p - p0;
} else {
if (!(flags & SUPPRESS)) mbp = va_arg(ap, char*);
n = 0;
memset(&mbs, 0, sizeof(mbs));
while ((wi = __fgetwc_unlock(fp)) != WEOF && width != 0 && ((c == CT_CCL && in_ccl(wi, ccl)) || (c == CT_STRING && !iswspace(wi)))) {
if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) {
nconv = wcrtomb(mbp, wi, &mbs);
if (nconv == (size_t)-1) goto input_failure;
} else {
nconv = wcrtomb(mbbuf, wi, &mbs);
if (nconv == (size_t)-1) goto input_failure;
if (nconv > width) break;
if (!(flags & SUPPRESS)) memcpy(mbp, mbbuf, nconv);
}
if (!(flags & SUPPRESS)) mbp += nconv;
width -= nconv;
n++;
}
if (wi != WEOF) __ungetwc(wi, fp);
}
if (c == CT_CCL && n == 0) goto match_failure;
if (!(flags & SUPPRESS)) {
if (flags & LONG) {
*p = L'\0';
} else {
*mbp = '\0';
}
++nassigned;
}
nread += n;
nconversions++;
break;
case CT_INT:
/* scan an integer as if by strtoimax/strtoumax */
if (width == 0 || width > sizeof(buf) / sizeof(*buf) - 1)
width = sizeof(buf) / sizeof(*buf) - 1;
flags |= SIGNOK | NDIGITS | NZDIGITS;
for (p = buf; width; width--) {
c = __fgetwc_unlock(fp);
/*
* Switch on the character; `goto ok'
* if we accept it as a part of number.
*/
switch (c) {
/*
* The digit 0 is always legal, but is
* special. For %i conversions, if no
* digits (zero or nonzero) have been
* scanned (only signs), we will have
* base==0. In that case, we should set
* it to 8 and enable 0b/0x prefixing.
* Also, if we have not scanned zero digits
* before this, do not turn off prefixing
* (someone else will turn it off if we
* have scanned any nonzero digits).
*/
case '0':
if (base == 0) {
base = 8;
flags |= PFBOK | PFXOK;
}
if (flags & NZDIGITS) {
flags &= ~(SIGNOK | NZDIGITS | NDIGITS);
} else {
flags &= ~(SIGNOK | PFBOK | PFXOK | NDIGITS);
}
goto ok;
/* 1 through 7 always legal */
case 'B':
case 'b':
// Is this 'b' potentially part of an "0b" prefix?
if ((flags & PFBOK) && p == buf + 1 + !!(flags & HAVESIGN)) {
base = 2;
flags &= ~PFBOK;
goto ok;
}
// No? Fall through and see if it's a hex digit instead then...
__BIONIC_FALLTHROUGH;
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case 'A':
case 'C':
case 'D':
case 'E':
case 'F':
case 'a':
case 'c':
case 'd':
case 'e':
case 'f':
if (base == 0) base = 10;
if (base != 16 && (int)(c - '0') >= base) break; /* not legal here */
flags &= ~(SIGNOK | PFBOK | PFXOK | NDIGITS);
goto ok;
/* sign ok only as first character */
case '+':
case '-':
if (flags & SIGNOK) {
flags &= ~SIGNOK;
flags |= HAVESIGN;
goto ok;
}
break;
/*
* x ok iff flag still set and 2nd char (or
* 3rd char if we have a sign).
*/
case 'x':
case 'X':
if ((flags & PFXOK) && p == buf + 1 + !!(flags & HAVESIGN)) {
base = 16; /* if %i */
flags &= ~PFXOK;
goto ok;
}
break;
}
/*
* If we got here, c is not a legal character
* for a number. Stop accumulating digits.
*/
if (c != WEOF) __ungetwc(c, fp);
break;
ok:
/*
* c is legal: store it and look at the next.
*/
*p++ = (wchar_t)c;
}
/*
* If we had only a sign, it is no good; push back the sign.
* If the number was `[-+]0[BbXx]`, push back and treat it
* as `[-+]0`.
*/
if (flags & NDIGITS) {
if (p > buf) __ungetwc(*--p, fp);
goto match_failure;
}
c = p[-1];
if ((base == 2 && (c == 'b' || c == 'B')) || c == 'x' || c == 'X') {
--p;
__ungetwc(c, fp);
}
if ((flags & SUPPRESS) == 0) {
uintmax_t res;
*p = '\0';
if (flags & UNSIGNED)
res = wcstoimax(buf, NULL, base);
else
res = wcstoumax(buf, NULL, base);
if (flags & POINTER)
*va_arg(ap, void**) = (void*)(uintptr_t)res;
else if (flags & MAXINT)
*va_arg(ap, intmax_t*) = res;
else if (flags & LLONG)
*va_arg(ap, long long*) = res;
else if (flags & SIZEINT)
*va_arg(ap, ssize_t*) = res;
else if (flags & PTRINT)
*va_arg(ap, ptrdiff_t*) = res;
else if (flags & LONG)
*va_arg(ap, long*) = res;
else if (flags & SHORT)
*va_arg(ap, short*) = res;
else if (flags & SHORTSHORT)
*va_arg(ap, signed char*) = res;
else
*va_arg(ap, int*) = res;
nassigned++;
}
nread += p - buf;
nconversions++;
break;
case CT_FLOAT:
/* scan a floating point number as if by strtod */
if (width == 0 || width > sizeof(buf) / sizeof(*buf) - 1)
width = sizeof(buf) / sizeof(*buf) - 1;
if ((width = wparsefloat(fp, buf, buf + width)) == 0) goto match_failure;
if ((flags & SUPPRESS) == 0) {
if (flags & LONGDBL) {
long double res = wcstold(buf, &p);
*va_arg(ap, long double*) = res;
} else if (flags & LONG) {
double res = wcstod(buf, &p);
*va_arg(ap, double*) = res;
} else {
float res = wcstof(buf, &p);
*va_arg(ap, float*) = res;
}
if (p - buf != (ptrdiff_t)width) abort();
nassigned++;
}
nread += width;
nconversions++;
break;
}
}
input_failure:
return (nconversions != 0 ? nassigned : EOF);
match_failure:
return (nassigned);
}
#pragma GCC diagnostic pop