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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:44:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:44:51 +0000 |
commit | 9e3c08db40b8916968b9f30096c7be3f00ce9647 (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /nsprpub/pr/src/io/prscanf.c | |
parent | Initial commit. (diff) | |
download | thunderbird-9e3c08db40b8916968b9f30096c7be3f00ce9647.tar.xz thunderbird-9e3c08db40b8916968b9f30096c7be3f00ce9647.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | nsprpub/pr/src/io/prscanf.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/nsprpub/pr/src/io/prscanf.c b/nsprpub/pr/src/io/prscanf.c new file mode 100644 index 0000000000..9923ea27c7 --- /dev/null +++ b/nsprpub/pr/src/io/prscanf.c @@ -0,0 +1,630 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* + * Scan functions for NSPR types + * + * Author: Wan-Teh Chang + * + * Acknowledgment: The implementation is inspired by the source code + * in P.J. Plauger's "The Standard C Library," Prentice-Hall, 1992. + */ + +#include <limits.h> +#include <ctype.h> +#include <string.h> +#include <stdlib.h> +#include "prprf.h" +#include "prdtoa.h" +#include "prlog.h" +#include "prerror.h" + +/* + * A function that reads a character from 'stream'. + * Returns the character read, or EOF if end of stream is reached. + */ +typedef int (*_PRGetCharFN)(void *stream); + +/* + * A function that pushes the character 'ch' back to 'stream'. + */ +typedef void (*_PRUngetCharFN)(void *stream, int ch); + +/* + * The size specifier for the integer and floating point number + * conversions in format control strings. + */ +typedef enum { + _PR_size_none, /* No size specifier is given */ + _PR_size_h, /* The 'h' specifier, suggesting "short" */ + _PR_size_l, /* The 'l' specifier, suggesting "long" */ + _PR_size_L, /* The 'L' specifier, meaning a 'long double' */ + _PR_size_ll /* The 'll' specifier, suggesting "long long" */ +} _PRSizeSpec; + +/* + * The collection of data that is passed between the scan function + * and its subordinate functions. The fields of this structure + * serve as the input or output arguments for these functions. + */ +typedef struct { + _PRGetCharFN get; /* get a character from input stream */ + _PRUngetCharFN unget; /* unget (push back) a character */ + void *stream; /* argument for get and unget */ + va_list ap; /* the variable argument list */ + int nChar; /* number of characters read from 'stream' */ + + PRBool assign; /* assign, or suppress assignment? */ + int width; /* field width */ + _PRSizeSpec sizeSpec; /* 'h', 'l', 'L', or 'll' */ + + PRBool converted; /* is the value actually converted? */ +} ScanfState; + +#define GET(state) ((state)->nChar++, (state)->get((state)->stream)) +#define UNGET(state, ch) \ + ((state)->nChar--, (state)->unget((state)->stream, ch)) + +/* + * The following two macros, GET_IF_WITHIN_WIDTH and WITHIN_WIDTH, + * are always used together. + * + * GET_IF_WITHIN_WIDTH calls the GET macro and assigns its return + * value to 'ch' only if we have not exceeded the field width of + * 'state'. Therefore, after GET_IF_WITHIN_WIDTH, the value of + * 'ch' is valid only if the macro WITHIN_WIDTH evaluates to true. + */ + +#define GET_IF_WITHIN_WIDTH(state, ch) \ + if (--(state)->width >= 0) { \ + (ch) = GET(state); \ + } +#define WITHIN_WIDTH(state) ((state)->width >= 0) + +/* + * _pr_strtoull: + * Convert a string to an unsigned 64-bit integer. The string + * 'str' is assumed to be a representation of the integer in + * base 'base'. + * + * Warning: + * - Only handle base 8, 10, and 16. + * - No overflow checking. + */ + +static PRUint64 +_pr_strtoull(const char *str, char **endptr, int base) +{ + static const int BASE_MAX = 16; + static const char digits[] = "0123456789abcdef"; + char *digitPtr; + PRUint64 x; /* return value */ + PRInt64 base64; + const char *cPtr; + PRBool negative; + const char *digitStart; + + PR_ASSERT(base == 0 || base == 8 || base == 10 || base == 16); + if (base < 0 || base == 1 || base > BASE_MAX) { + if (endptr) { + *endptr = (char *) str; + return LL_ZERO; + } + } + + cPtr = str; + while (isspace(*cPtr)) { + ++cPtr; + } + + negative = PR_FALSE; + if (*cPtr == '-') { + negative = PR_TRUE; + cPtr++; + } else if (*cPtr == '+') { + cPtr++; + } + + if (base == 16) { + if (*cPtr == '0' && (cPtr[1] == 'x' || cPtr[1] == 'X')) { + cPtr += 2; + } + } else if (base == 0) { + if (*cPtr != '0') { + base = 10; + } else if (cPtr[1] == 'x' || cPtr[1] == 'X') { + base = 16; + cPtr += 2; + } else { + base = 8; + } + } + PR_ASSERT(base != 0); + LL_I2L(base64, base); + digitStart = cPtr; + + /* Skip leading zeros */ + while (*cPtr == '0') { + cPtr++; + } + + LL_I2L(x, 0); + while ((digitPtr = (char*)memchr(digits, tolower(*cPtr), base)) != NULL) { + PRUint64 d; + + LL_I2L(d, (digitPtr - digits)); + LL_MUL(x, x, base64); + LL_ADD(x, x, d); + cPtr++; + } + + if (cPtr == digitStart) { + if (endptr) { + *endptr = (char *) str; + } + return LL_ZERO; + } + + if (negative) { +#ifdef HAVE_LONG_LONG + /* The cast to a signed type is to avoid a compiler warning */ + x = -(PRInt64)x; +#else + LL_NEG(x, x); +#endif + } + + if (endptr) { + *endptr = (char *) cPtr; + } + return x; +} + +/* + * The maximum field width (in number of characters) that is enough + * (may be more than necessary) to represent a 64-bit integer or + * floating point number. + */ +#define FMAX 31 +#define DECIMAL_POINT '.' + +static PRStatus +GetInt(ScanfState *state, int code) +{ + char buf[FMAX + 1], *p; + int ch = 0; + static const char digits[] = "0123456789abcdefABCDEF"; + PRBool seenDigit = PR_FALSE; + int base; + int dlen; + + switch (code) { + case 'd': case 'u': + base = 10; + break; + case 'i': + base = 0; + break; + case 'x': case 'X': case 'p': + base = 16; + break; + case 'o': + base = 8; + break; + default: + return PR_FAILURE; + } + if (state->width == 0 || state->width > FMAX) { + state->width = FMAX; + } + p = buf; + GET_IF_WITHIN_WIDTH(state, ch); + if (WITHIN_WIDTH(state) && (ch == '+' || ch == '-')) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + } + if (WITHIN_WIDTH(state) && ch == '0') { + seenDigit = PR_TRUE; + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + if (WITHIN_WIDTH(state) + && (ch == 'x' || ch == 'X') + && (base == 0 || base == 16)) { + base = 16; + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + } else if (base == 0) { + base = 8; + } + } + if (base == 0 || base == 10) { + dlen = 10; + } else if (base == 8) { + dlen = 8; + } else { + PR_ASSERT(base == 16); + dlen = 16 + 6; /* 16 digits, plus 6 in uppercase */ + } + while (WITHIN_WIDTH(state) && memchr(digits, ch, dlen)) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + seenDigit = PR_TRUE; + } + if (WITHIN_WIDTH(state)) { + UNGET(state, ch); + } + if (!seenDigit) { + return PR_FAILURE; + } + *p = '\0'; + if (state->assign) { + if (code == 'd' || code == 'i') { + if (state->sizeSpec == _PR_size_ll) { + PRInt64 llval = _pr_strtoull(buf, NULL, base); + *va_arg(state->ap, PRInt64 *) = llval; + } else { + long lval = strtol(buf, NULL, base); + + if (state->sizeSpec == _PR_size_none) { + *va_arg(state->ap, PRIntn *) = lval; + } else if (state->sizeSpec == _PR_size_h) { + *va_arg(state->ap, PRInt16 *) = (PRInt16)lval; + } else if (state->sizeSpec == _PR_size_l) { + *va_arg(state->ap, PRInt32 *) = lval; + } else { + return PR_FAILURE; + } + } + } else { + if (state->sizeSpec == _PR_size_ll) { + PRUint64 llval = _pr_strtoull(buf, NULL, base); + *va_arg(state->ap, PRUint64 *) = llval; + } else { + unsigned long lval = strtoul(buf, NULL, base); + + if (state->sizeSpec == _PR_size_none) { + *va_arg(state->ap, PRUintn *) = lval; + } else if (state->sizeSpec == _PR_size_h) { + *va_arg(state->ap, PRUint16 *) = (PRUint16)lval; + } else if (state->sizeSpec == _PR_size_l) { + *va_arg(state->ap, PRUint32 *) = lval; + } else { + return PR_FAILURE; + } + } + } + state->converted = PR_TRUE; + } + return PR_SUCCESS; +} + +static PRStatus +GetFloat(ScanfState *state) +{ + char buf[FMAX + 1], *p; + int ch = 0; + PRBool seenDigit = PR_FALSE; + + if (state->width == 0 || state->width > FMAX) { + state->width = FMAX; + } + p = buf; + GET_IF_WITHIN_WIDTH(state, ch); + if (WITHIN_WIDTH(state) && (ch == '+' || ch == '-')) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + } + while (WITHIN_WIDTH(state) && isdigit(ch)) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + seenDigit = PR_TRUE; + } + if (WITHIN_WIDTH(state) && ch == DECIMAL_POINT) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + while (WITHIN_WIDTH(state) && isdigit(ch)) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + seenDigit = PR_TRUE; + } + } + + /* + * This is not robust. For example, "1.2e+" would confuse + * the code below to read 'e' and '+', only to realize that + * it should have stopped at "1.2". But we can't push back + * more than one character, so there is nothing I can do. + */ + + /* Parse exponent */ + if (WITHIN_WIDTH(state) && (ch == 'e' || ch == 'E') && seenDigit) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + if (WITHIN_WIDTH(state) && (ch == '+' || ch == '-')) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + } + while (WITHIN_WIDTH(state) && isdigit(ch)) { + *p++ = ch; + GET_IF_WITHIN_WIDTH(state, ch); + } + } + if (WITHIN_WIDTH(state)) { + UNGET(state, ch); + } + if (!seenDigit) { + return PR_FAILURE; + } + *p = '\0'; + if (state->assign) { + PRFloat64 dval = PR_strtod(buf, NULL); + + state->converted = PR_TRUE; + if (state->sizeSpec == _PR_size_l) { + *va_arg(state->ap, PRFloat64 *) = dval; + } else if (state->sizeSpec == _PR_size_L) { + *va_arg(state->ap, long double *) = dval; + } else { + *va_arg(state->ap, float *) = (float) dval; + } + } + return PR_SUCCESS; +} + +/* + * Convert, and return the end of the conversion spec. + * Return NULL on error. + */ + +static const char * +Convert(ScanfState *state, const char *fmt) +{ + const char *cPtr; + int ch; + char *cArg = NULL; + + state->converted = PR_FALSE; + cPtr = fmt; + if (*cPtr != 'c' && *cPtr != 'n' && *cPtr != '[') { + do { + ch = GET(state); + } while (isspace(ch)); + UNGET(state, ch); + } + switch (*cPtr) { + case 'c': + if (state->assign) { + cArg = va_arg(state->ap, char *); + } + if (state->width == 0) { + state->width = 1; + } + for (; state->width > 0; state->width--) { + ch = GET(state); + if (ch == EOF) { + return NULL; + } + if (state->assign) { + *cArg++ = ch; + } + } + if (state->assign) { + state->converted = PR_TRUE; + } + break; + case 'p': + case 'd': case 'i': case 'o': + case 'u': case 'x': case 'X': + if (GetInt(state, *cPtr) == PR_FAILURE) { + return NULL; + } + break; + case 'e': case 'E': case 'f': + case 'g': case 'G': + if (GetFloat(state) == PR_FAILURE) { + return NULL; + } + break; + case 'n': + /* do not consume any input */ + if (state->assign) { + switch (state->sizeSpec) { + case _PR_size_none: + *va_arg(state->ap, PRIntn *) = state->nChar; + break; + case _PR_size_h: + *va_arg(state->ap, PRInt16 *) = state->nChar; + break; + case _PR_size_l: + *va_arg(state->ap, PRInt32 *) = state->nChar; + break; + case _PR_size_ll: + LL_I2L(*va_arg(state->ap, PRInt64 *), state->nChar); + break; + default: + PR_ASSERT(0); + } + } + break; + case 's': + if (state->width == 0) { + state->width = INT_MAX; + } + if (state->assign) { + cArg = va_arg(state->ap, char *); + } + for (; state->width > 0; state->width--) { + ch = GET(state); + if ((ch == EOF) || isspace(ch)) { + UNGET(state, ch); + break; + } + if (state->assign) { + *cArg++ = ch; + } + } + if (state->assign) { + *cArg = '\0'; + state->converted = PR_TRUE; + } + break; + case '%': + ch = GET(state); + if (ch != '%') { + UNGET(state, ch); + return NULL; + } + break; + case '[': + { + PRBool complement = PR_FALSE; + const char *closeBracket; + size_t n; + + if (*++cPtr == '^') { + complement = PR_TRUE; + cPtr++; + } + closeBracket = strchr(*cPtr == ']' ? cPtr + 1 : cPtr, ']'); + if (closeBracket == NULL) { + return NULL; + } + n = closeBracket - cPtr; + if (state->width == 0) { + state->width = INT_MAX; + } + if (state->assign) { + cArg = va_arg(state->ap, char *); + } + for (; state->width > 0; state->width--) { + ch = GET(state); + if ((ch == EOF) + || (!complement && !memchr(cPtr, ch, n)) + || (complement && memchr(cPtr, ch, n))) { + UNGET(state, ch); + break; + } + if (state->assign) { + *cArg++ = ch; + } + } + if (state->assign) { + *cArg = '\0'; + state->converted = PR_TRUE; + } + cPtr = closeBracket; + } + break; + default: + return NULL; + } + return cPtr; +} + +static PRInt32 +DoScanf(ScanfState *state, const char *fmt) +{ + PRInt32 nConverted = 0; + const char *cPtr; + int ch; + + state->nChar = 0; + cPtr = fmt; + while (1) { + if (isspace(*cPtr)) { + /* white space: skip */ + do { + cPtr++; + } while (isspace(*cPtr)); + do { + ch = GET(state); + } while (isspace(ch)); + UNGET(state, ch); + } else if (*cPtr == '%') { + /* format spec: convert */ + cPtr++; + state->assign = PR_TRUE; + if (*cPtr == '*') { + cPtr++; + state->assign = PR_FALSE; + } + for (state->width = 0; isdigit(*cPtr); cPtr++) { + state->width = state->width * 10 + *cPtr - '0'; + } + state->sizeSpec = _PR_size_none; + if (*cPtr == 'h') { + cPtr++; + state->sizeSpec = _PR_size_h; + } else if (*cPtr == 'l') { + cPtr++; + if (*cPtr == 'l') { + cPtr++; + state->sizeSpec = _PR_size_ll; + } else { + state->sizeSpec = _PR_size_l; + } + } else if (*cPtr == 'L') { + cPtr++; + state->sizeSpec = _PR_size_L; + } + cPtr = Convert(state, cPtr); + if (cPtr == NULL) { + return (nConverted > 0 ? nConverted : EOF); + } + if (state->converted) { + nConverted++; + } + cPtr++; + } else { + /* others: must match */ + if (*cPtr == '\0') { + return nConverted; + } + ch = GET(state); + if (ch != *cPtr) { + UNGET(state, ch); + return nConverted; + } + cPtr++; + } + } +} + +static int +StringGetChar(void *stream) +{ + char *cPtr = *((char **) stream); + + if (*cPtr == '\0') { + return EOF; + } + *((char **) stream) = cPtr + 1; + return (unsigned char) *cPtr; +} + +static void +StringUngetChar(void *stream, int ch) +{ + char *cPtr = *((char **) stream); + + if (ch != EOF) { + *((char **) stream) = cPtr - 1; + } +} + +PR_IMPLEMENT(PRInt32) +PR_sscanf(const char *buf, const char *fmt, ...) +{ + PRInt32 rv; + ScanfState state; + + state.get = &StringGetChar; + state.unget = &StringUngetChar; + state.stream = (void *) &buf; + va_start(state.ap, fmt); + rv = DoScanf(&state, fmt); + va_end(state.ap); + return rv; +} |