Support %mc/%ms/%m[ in sscanf.
Also support the "long" (wchar_t) variants.
Bug: http://b/68672236
Test: ran tests
Change-Id: I060e98b4d2feb61e12986d9d51e4710b2b1d9724
diff --git a/libc/stdio/vfscanf.cpp b/libc/stdio/vfscanf.cpp
new file mode 100644
index 0000000..f2e136c
--- /dev/null
+++ b/libc/stdio/vfscanf.cpp
@@ -0,0 +1,817 @@
+/* $OpenBSD: vfscanf.c,v 1.31 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 <inttypes.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/param.h>
+#include <wctype.h>
+#include "local.h"
+
+#include <private/bionic_ctype.h>
+#include <private/bionic_fortify.h>
+#include <private/bionic_mbstate.h>
+
+#define BUF 513 /* Maximum length of numeric string. */
+
+// Flags used during conversion.
+// Size/type:
+#define LONG 0x00001 // l: long or double
+#define LONGDBL 0x00002 // L: long double
+#define SHORT 0x00004 // h: short
+#define SHORTSHORT 0x00008 // hh: 8 bit integer
+#define LLONG 0x00010 // ll: long long (+ deprecated q: quad)
+#define POINTER 0x00020 // p: void* (as hex)
+#define SIZEINT 0x00040 // z: (signed) size_t
+#define MAXINT 0x00080 // j: intmax_t
+#define PTRINT 0x00100 // t: ptrdiff_t
+#define NOSKIP 0x00200 // [ or c: do not skip blanks
+// Modifiers:
+#define SUPPRESS 0x00400 // *: suppress assignment
+#define UNSIGNED 0x00800 // %[oupxX] conversions
+#define ALLOCATE 0x01000 // m: allocate a char*
+// Internal use during integer parsing:
+#define SIGNOK 0x02000 // +/- is (still) legal
+#define HAVESIGN 0x04000 // Sign detected
+#define NDIGITS 0x08000 // No digits detected
+#define PFXOK 0x10000 // "0x" prefix is (still) legal
+#define NZDIGITS 0x20000 // No 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: strtoimax/strtoumax
+#define CT_FLOAT 4 // Float: strtod
+
+static const unsigned char* __sccl(char*, const unsigned char*);
+
+/*
+ * Internal, unlocked version of vfscanf
+ */
+int __svfscanf(FILE* fp, const char* fmt0, va_list ap) {
+ const unsigned char* fmt = reinterpret_cast<const unsigned char*>(fmt0);
+ int c; /* character from format, or conversion */
+ size_t width; /* field width, or 0 */
+ char* p;
+ wchar_t* wcp;
+ size_t n;
+ int flags; /* flags as defined above */
+ int nassigned; /* number of fields assigned */
+ int nread; /* number of characters consumed from fp */
+ int base; /* base argument to strtoimax/strtouimax */
+ char ccltab[256]; /* character class table for %[...] */
+ char buf[BUF]; /* buffer for numeric conversions */
+ size_t nconv; /* length of multibyte sequence converted */
+ mbstate_t mbs;
+ void* allocation = NULL; // Allocated but unassigned result for %mc/%ms/%m[.
+ size_t capacity = 0; // Number of char/wchar_t units allocated in `allocation`.
+
+ /* `basefix' is used to avoid `if' tests in the integer scanner */
+ static short basefix[17] = { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
+
+ _SET_ORIENTATION(fp, -1);
+
+ nassigned = 0;
+ nread = 0;
+ for (;;) {
+ c = *fmt++;
+ if (c == 0) return nassigned;
+ if (IsSpace(c)) {
+ while ((fp->_r > 0 || __srefill(fp) == 0) && IsSpace(*fp->_p)) nread++, fp->_r--, fp->_p++;
+ 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++;
+ switch (c) {
+ case '%':
+literal:
+ if (fp->_r <= 0 && __srefill(fp)) goto input_failure;
+ if (*fp->_p != c) goto match_failure;
+ fp->_r--, fp->_p++;
+ 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 'm':
+ flags |= ALLOCATE;
+ 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 'D': /* compat */
+ flags |= LONG;
+ /* FALLTHROUGH */
+ case 'd':
+ c = CT_INT;
+ base = 10;
+ break;
+
+ case 'i':
+ c = CT_INT;
+ base = 0;
+ break;
+
+ case 'O': /* compat */
+ flags |= LONG;
+ /* FALLTHROUGH */
+ case 'o':
+ c = CT_INT;
+ flags |= UNSIGNED;
+ base = 8;
+ break;
+
+ case 'u':
+ c = CT_INT;
+ flags |= UNSIGNED;
+ base = 10;
+ break;
+
+ 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 '[':
+ fmt = __sccl(ccltab, 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':
+ 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 (IsUpper(c)) flags |= LONG;
+ c = CT_INT;
+ base = 10;
+ break;
+ }
+
+ if ((flags & ALLOCATE) != 0 && c > CT_STRING) {
+ __fortify_fatal("scanf 'm' only works with %%c/%%s/%%[");
+ }
+ if ((flags & (ALLOCATE|SUPPRESS)) == (ALLOCATE|SUPPRESS)) {
+ __fortify_fatal("scanf 'm' makes no sense with '*'");
+ }
+
+ /*
+ * We have a conversion that requires input.
+ */
+ if (fp->_r <= 0 && __srefill(fp)) goto input_failure;
+
+ /*
+ * Consume leading white space, except for formats
+ * that suppress this.
+ */
+ if ((flags & NOSKIP) == 0) {
+ while (IsSpace(*fp->_p)) {
+ nread++;
+ if (--fp->_r > 0) {
+ fp->_p++;
+ } else if (__srefill(fp)) {
+ 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.
+ */
+ }
+
+ /*
+ * Do the conversion.
+ */
+ switch (c) {
+ case CT_CHAR:
+ /* scan arbitrary characters (sets NOSKIP) */
+ if (width == 0) width = 1;
+ if (flags & LONG) {
+ if (flags & ALLOCATE) {
+ allocation = wcp = reinterpret_cast<wchar_t*>(malloc(width * sizeof(wchar_t)));
+ if (allocation == NULL) goto allocation_failure;
+ } else if (flags & SUPPRESS) {
+ wcp = NULL;
+ } else {
+ wcp = va_arg(ap, wchar_t*);
+ }
+ size_t bytes = 0;
+ while (width != 0) {
+ if (bytes == MB_CUR_MAX) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ buf[bytes++] = *fp->_p;
+ fp->_p++;
+ fp->_r--;
+ memset(&mbs, 0, sizeof(mbs));
+ nconv = mbrtowc(wcp, buf, bytes, &mbs);
+ if (nconv == __MB_ERR_ILLEGAL_SEQUENCE) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ if (nconv == 0 && !(flags & SUPPRESS)) *wcp = L'\0';
+ if (nconv != __MB_ERR_INCOMPLETE_SEQUENCE) {
+ nread += bytes;
+ width--;
+ if (!(flags & SUPPRESS)) wcp++;
+ bytes = 0;
+ }
+ if (fp->_r <= 0 && __srefill(fp)) {
+ if (bytes != 0) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ break;
+ }
+ }
+ if (allocation != NULL) {
+ *va_arg(ap, wchar_t**) = reinterpret_cast<wchar_t*>(allocation);
+ allocation = NULL;
+ }
+ if (!(flags & SUPPRESS)) nassigned++;
+ } else if (flags & SUPPRESS) {
+ size_t sum = 0;
+ for (;;) {
+ if ((n = fp->_r) < width) {
+ sum += n;
+ width -= n;
+ fp->_p += n;
+ if (__srefill(fp)) {
+ if (sum == 0) goto input_failure;
+ break;
+ }
+ } else {
+ sum += width;
+ fp->_r -= width;
+ fp->_p += width;
+ break;
+ }
+ }
+ nread += sum;
+ } else {
+ if (flags & ALLOCATE) {
+ allocation = p = reinterpret_cast<char*>(malloc(width));
+ if (allocation == NULL) goto allocation_failure;
+ } else {
+ p = va_arg(ap, char*);
+ }
+ size_t r = fread(p, 1, width, fp);
+ if (r == 0) goto input_failure;
+ if (allocation != NULL) {
+ *va_arg(ap, char**) = reinterpret_cast<char*>(allocation);
+ allocation = NULL;
+ }
+ nread += r;
+ nassigned++;
+ }
+ 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_MAX;
+ if (flags & LONG) {
+ // TODO: since no-one cares, replace this with a simple fgetwc loop?
+ n = 0;
+ if (flags & ALLOCATE) {
+ capacity = MIN(width, 32);
+ allocation = wcp = reinterpret_cast<wchar_t*>(malloc(sizeof(wchar_t) * capacity));
+ if (allocation == NULL) goto allocation_failure;
+ } else if (flags & SUPPRESS) {
+ wcp = NULL;
+ } else {
+ wcp = va_arg(ap, wchar_t*);
+ }
+ size_t bytes = 0;
+ while ((c == CT_CCL || !IsSpace(*fp->_p)) && width != 0) {
+ if (bytes == MB_CUR_MAX) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ buf[bytes++] = *fp->_p;
+ fp->_p++;
+ fp->_r--;
+ wchar_t wc = L'\0';
+ memset(&mbs, 0, sizeof(mbs));
+ nconv = mbrtowc(&wc, buf, bytes, &mbs);
+ if (nconv == __MB_ERR_ILLEGAL_SEQUENCE) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ if (nconv != __MB_ERR_INCOMPLETE_SEQUENCE) {
+ if ((c == CT_CCL && wctob(wc) != EOF && !ccltab[wctob(wc)]) || (c == CT_STRING && iswspace(wc))) {
+ while (bytes != 0) {
+ bytes--;
+ ungetc(buf[bytes], fp);
+ }
+ break;
+ }
+ if (wcp) wcp[n] = wc;
+ n++;
+ if (allocation != NULL && n == capacity) {
+ capacity *= 2;
+ wchar_t* new_allocation =
+ reinterpret_cast<wchar_t*>(realloc(allocation, sizeof(wchar_t) * capacity));
+ if (new_allocation == NULL) goto allocation_failure;
+ allocation = wcp = new_allocation;
+ }
+ nread += bytes;
+ width--;
+ bytes = 0;
+ }
+ if (fp->_r <= 0 && __srefill(fp)) {
+ if (bytes != 0) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ break;
+ }
+ }
+ if (c == CT_CCL && bytes != 0) {
+ fp->_flags |= __SERR;
+ goto input_failure;
+ }
+ if (allocation != NULL) {
+ *va_arg(ap, wchar_t**) = reinterpret_cast<wchar_t*>(allocation);
+ allocation = NULL;
+ }
+ } else if (flags & SUPPRESS) {
+ n = 0;
+ while ((c == CT_CCL && ccltab[*fp->_p]) || (c == CT_STRING && !IsSpace(*fp->_p))) {
+ n++, fp->_r--, fp->_p++;
+ if (--width == 0) break;
+ if (fp->_r <= 0 && __srefill(fp)) {
+ if (c == CT_CCL && n == 0) goto input_failure;
+ break;
+ }
+ }
+ nread += n;
+ } else {
+ if (flags & ALLOCATE) {
+ capacity = MIN(width, 32);
+ allocation = p = reinterpret_cast<char*>(malloc(capacity));
+ if (allocation == NULL) goto allocation_failure;
+ } else {
+ p = va_arg(ap, char*);
+ }
+ n = 0;
+ while ((c == CT_CCL && ccltab[*fp->_p]) || (c == CT_STRING && !IsSpace(*fp->_p))) {
+ fp->_r--;
+ p[n++] = *fp->_p++;
+ if (allocation != NULL && n == capacity) {
+ capacity *= 2;
+ char* new_allocation = reinterpret_cast<char*>(realloc(allocation, capacity));
+ if (new_allocation == NULL) goto allocation_failure;
+ allocation = p = new_allocation;
+ }
+ if (--width == 0) break;
+ if (fp->_r <= 0 && __srefill(fp)) {
+ if (c == CT_CCL && n == 0) goto input_failure;
+ break;
+ }
+ }
+ nread += n;
+ if (allocation != NULL) {
+ *va_arg(ap, char**) = reinterpret_cast<char*>(allocation);
+ allocation = NULL;
+ }
+ }
+ if (c == CT_CCL && n == 0) goto match_failure;
+ if (!(flags & SUPPRESS)) {
+ if (flags & LONG) {
+ wcp[n] = L'\0';
+ } else {
+ p[n] = '\0';
+ }
+ ++nassigned;
+ }
+ break;
+
+ case CT_INT:
+ /* scan an integer as if by strtoimax/strtoumax */
+#ifdef hardway
+ if (width == 0 || width > sizeof(buf) - 1) width = sizeof(buf) - 1;
+#else
+ /* size_t is unsigned, hence this optimisation */
+ if (--width > sizeof(buf) - 2) width = sizeof(buf) - 2;
+ width++;
+#endif
+ flags |= SIGNOK | NDIGITS | NZDIGITS;
+ for (p = buf; width; width--) {
+ c = *fp->_p;
+ /*
+ * 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 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 |= PFXOK;
+ }
+ if (flags & NZDIGITS)
+ flags &= ~(SIGNOK | NZDIGITS | NDIGITS);
+ else
+ flags &= ~(SIGNOK | PFXOK | NDIGITS);
+ goto ok;
+
+ /* 1 through 7 always legal */
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ base = basefix[base];
+ flags &= ~(SIGNOK | PFXOK | NDIGITS);
+ goto ok;
+
+ /* digits 8 and 9 ok iff decimal or hex */
+ case '8':
+ case '9':
+ base = basefix[base];
+ if (base <= 8) break; /* not legal here */
+ flags &= ~(SIGNOK | PFXOK | NDIGITS);
+ goto ok;
+
+ /* letters ok iff hex */
+ case 'A':
+ case 'B':
+ case 'C':
+ case 'D':
+ case 'E':
+ case 'F':
+ case 'a':
+ case 'b':
+ case 'c':
+ case 'd':
+ case 'e':
+ case 'f':
+ /* no need to fix base here */
+ if (base <= 10) break; /* not legal here */
+ flags &= ~(SIGNOK | 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.
+ */
+ break;
+ ok:
+ /*
+ * c is legal: store it and look at the next.
+ */
+ *p++ = c;
+ if (--fp->_r > 0)
+ fp->_p++;
+ else if (__srefill(fp))
+ break; /* EOF */
+ }
+ /*
+ * If we had only a sign, it is no good; push
+ * back the sign. If the number ends in `x',
+ * it was [sign] '0' 'x', so push back the x
+ * and treat it as [sign] '0'.
+ */
+ if (flags & NDIGITS) {
+ if (p > buf) (void)ungetc(*(u_char*)--p, fp);
+ goto match_failure;
+ }
+ c = ((u_char*)p)[-1];
+ if (c == 'x' || c == 'X') {
+ --p;
+ (void)ungetc(c, fp);
+ }
+ if ((flags & SUPPRESS) == 0) {
+ uintmax_t res;
+
+ *p = '\0';
+ if (flags & UNSIGNED) {
+ res = strtoumax(buf, NULL, base);
+ } else {
+ res = strtoimax(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;
+ break;
+
+ case CT_FLOAT:
+ /* scan a floating point number as if by strtod */
+ if (width == 0 || width > sizeof(buf) - 1) width = sizeof(buf) - 1;
+ if ((width = parsefloat(fp, buf, buf + width)) == 0) goto match_failure;
+ if ((flags & SUPPRESS) == 0) {
+ if (flags & LONGDBL) {
+ long double res = strtold(buf, &p);
+ *va_arg(ap, long double*) = res;
+ } else if (flags & LONG) {
+ double res = strtod(buf, &p);
+ *va_arg(ap, double*) = res;
+ } else {
+ float res = strtof(buf, &p);
+ *va_arg(ap, float*) = res;
+ }
+ if ((size_t)(p - buf) != width) abort();
+ nassigned++;
+ }
+ nread += width;
+ break;
+ }
+ }
+allocation_failure:
+input_failure:
+ free(allocation);
+ if (nassigned == 0) nassigned = -1;
+match_failure:
+ return nassigned;
+}
+
+/*
+ * Fill in the given table from the scanset at the given format
+ * (just after `['). Return a pointer to the character past the
+ * closing `]'. The table has a 1 wherever characters should be
+ * considered part of the scanset.
+ */
+static const unsigned char* __sccl(char* tab, const unsigned char* fmt) {
+ int c, n, v;
+
+ /* first `clear' the whole table */
+ c = *fmt++; /* first char hat => negated scanset */
+ if (c == '^') {
+ v = 1; /* default => accept */
+ c = *fmt++; /* get new first char */
+ } else
+ v = 0; /* default => reject */
+ /* should probably use memset here */
+ for (n = 0; n < 256; n++) tab[n] = v;
+ if (c == 0) return (fmt - 1); /* format ended before closing ] */
+
+ /*
+ * Now set the entries corresponding to the actual scanset
+ * to the opposite of the above.
+ *
+ * The first character may be ']' (or '-') without being special;
+ * the last character may be '-'.
+ */
+ v = 1 - v;
+ for (;;) {
+ tab[c] = v; /* take character c */
+ doswitch:
+ n = *fmt++; /* and examine the next */
+ switch (n) {
+ case 0: /* format ended too soon */
+ return (fmt - 1);
+
+ case '-':
+ /*
+ * A scanset of the form
+ * [01+-]
+ * is defined as `the digit 0, the digit 1,
+ * the character +, the character -', but
+ * the effect of a scanset such as
+ * [a-zA-Z0-9]
+ * is implementation defined. The V7 Unix
+ * scanf treats `a-z' as `the letters a through
+ * z', but treats `a-a' as `the letter a, the
+ * character -, and the letter a'.
+ *
+ * For compatibility, the `-' is not considerd
+ * to define a range if the character following
+ * it is either a close bracket (required by ANSI)
+ * or is not numerically greater than the character
+ * we just stored in the table (c).
+ */
+ n = *fmt;
+ if (n == ']' || n < c) {
+ c = '-';
+ break; /* resume the for(;;) */
+ }
+ fmt++;
+ do { /* fill in the range */
+ tab[++c] = v;
+ } while (c < n);
+#if 1 /* XXX another disgusting compatibility hack */
+ /*
+ * Alas, the V7 Unix scanf also treats formats
+ * such as [a-c-e] as `the letters a through e'.
+ * This too is permitted by the standard....
+ */
+ goto doswitch;
+#else
+ c = *fmt++;
+ if (c == 0) return (fmt - 1);
+ if (c == ']') return (fmt);
+#endif
+ break;
+
+ case ']': /* end of scanset */
+ return fmt;
+
+ default: /* just another character */
+ c = n;
+ break;
+ }
+ }
+ /* NOTREACHED */
+}