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Diffstat (limited to 'private/crt32/convert/strtol.c')
| -rw-r--r-- | private/crt32/convert/strtol.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/private/crt32/convert/strtol.c b/private/crt32/convert/strtol.c new file mode 100644 index 000000000..d74bde7be --- /dev/null +++ b/private/crt32/convert/strtol.c @@ -0,0 +1,227 @@ +/*** +*strtol.c - Contains C runtimes strtol and strtoul +* +* Copyright (c) 1989-1993, Microsoft Corporation. All rights reserved. +* +*Purpose: +* strtol - convert ascii string to long signed integer +* strtoul - convert ascii string to long unsigned integer +* +*Revision History: +* 06-05-89 PHG Module created, based on strtol.asm +* 03-06-90 GJF Fixed calling type, added #include <cruntime.h> +* and fixed the copyright. Also, cleaned up the +* formatting a bit. +* 03-07-90 GJF Fixed compiler warnings (added const qualifier to +* an arg type and local var type). +* 03-23-90 GJF Made strtoxl() _CALLTYPE4. +* 08-13-90 SBM Compiles cleanly with -W3 +* 09-27-90 GJF New-style function declarators. +* 10-24-91 GJF Had to cast LONG_MAX to unsigned long in expr. to +* mollify MIPS compiler. +* 10-21-92 GJF Made char-to-int conversions unsigned. +* 04-21-93 GJF Removed assumption that LONG_MIN == -LONG_MAX. +* 05-10-93 GJF Fixed error check. +* 05-20-93 GJF Nothing like taking ugly code and making prettier... +* and wrong. Fixed bug introduced on 5-10. +* +*******************************************************************************/ + +#include <cruntime.h> +#include <stdlib.h> +#include <limits.h> +#include <errno.h> +#include <ctype.h> + + +/*** +*strtol, strtoul(nptr,endptr,ibase) - Convert ascii string to long un/signed +* int. +* +*Purpose: +* Convert an ascii string to a long 32-bit value. The base +* used for the caculations is supplied by the caller. The base +* must be in the range 0, 2-36. If a base of 0 is supplied, the +* ascii string must be examined to determine the base of the +* number: +* (a) First char = '0', second char = 'x' or 'X', +* use base 16. +* (b) First char = '0', use base 8 +* (c) First char in range '1' - '9', use base 10. +* +* If the 'endptr' value is non-NULL, then strtol/strtoul places +* a pointer to the terminating character in this value. +* See ANSI standard for details +* +*Entry: +* nptr == NEAR/FAR pointer to the start of string. +* endptr == NEAR/FAR pointer to the end of the string. +* ibase == integer base to use for the calculations. +* +* string format: [whitespace] [sign] [0] [x] [digits/letters] +* +*Exit: +* Good return: +* result +* +* Overflow return: +* strtol -- LONG_MAX or LONG_MIN +* strtoul -- ULONG_MAX +* strtol/strtoul -- errno == ERANGE +* +* No digits or bad base return: +* 0 +* endptr = nptr* +* +*Exceptions: +* None. +*******************************************************************************/ + +/* flag values */ +#define FL_UNSIGNED 1 /* strtoul called */ +#define FL_NEG 2 /* negative sign found */ +#define FL_OVERFLOW 4 /* overflow occured */ +#define FL_READDIGIT 8 /* we've read at least one correct digit */ + + +static unsigned long _CRTAPI3 strtoxl ( + const char *nptr, + const char **endptr, + int ibase, + int flags + ) +{ + const char *p; + char c; + unsigned long number; + unsigned digval; + unsigned long maxval; + + p = nptr; /* p is our scanning pointer */ + number = 0; /* start with zero */ + + c = *p++; /* read char */ + while ( isspace((int)(unsigned char)c) ) + c = *p++; /* skip whitespace */ + + if (c == '-') { + flags |= FL_NEG; /* remember minus sign */ + c = *p++; + } + else if (c == '+') + c = *p++; /* skip sign */ + + if (ibase < 0 || ibase == 1 || ibase > 36) { + /* bad base! */ + if (endptr) + /* store beginning of string in endptr */ + *endptr = nptr; + return 0L; /* return 0 */ + } + else if (ibase == 0) { + /* determine base free-lance, based on first two chars of + string */ + if (c != '0') + ibase = 10; + else if (*p == 'x' || *p == 'X') + ibase = 16; + else + ibase = 8; + } + + if (ibase == 16) { + /* we might have 0x in front of number; remove if there */ + if (c == '0' && (*p == 'x' || *p == 'X')) { + ++p; + c = *p++; /* advance past prefix */ + } + } + + /* if our number exceeds this, we will overflow on multiply */ + maxval = ULONG_MAX / ibase; + + + for (;;) { /* exit in middle of loop */ + /* convert c to value */ + if ( isdigit((int)(unsigned char)c) ) + digval = c - '0'; + else if ( isalpha((int)(unsigned char)c) ) + digval = toupper(c) - 'A' + 10; + else + break; + if (digval >= (unsigned)ibase) + break; /* exit loop if bad digit found */ + + /* record the fact we have read one digit */ + flags |= FL_READDIGIT; + + /* we now need to compute number = number * base + digval, + but we need to know if overflow occured. This requires + a tricky pre-check. */ + + if (number < maxval || (number == maxval && + (unsigned long)digval <= ULONG_MAX % ibase)) { + /* we won't overflow, go ahead and multiply */ + number = number * ibase + digval; + } + else { + /* we would have overflowed -- set the overflow flag */ + flags |= FL_OVERFLOW; + } + + c = *p++; /* read next digit */ + } + + --p; /* point to place that stopped scan */ + + if (!(flags & FL_READDIGIT)) { + /* no number there; return 0 and point to beginning of + string */ + if (endptr) + /* store beginning of string in endptr later on */ + p = nptr; + number = 0L; /* return 0 */ + } + else if ( (flags & FL_OVERFLOW) || + ( !(flags & FL_UNSIGNED) && + ( ( (flags & FL_NEG) && (number > -LONG_MIN) ) || + ( !(flags & FL_NEG) && (number > LONG_MAX) ) ) ) ) + { + /* overflow or signed overflow occurred */ + errno = ERANGE; + if ( flags & FL_UNSIGNED ) + number = ULONG_MAX; + else if ( flags & FL_NEG ) + number = (unsigned long)(-LONG_MIN); + else + number = LONG_MAX; + } + + if (endptr != NULL) + /* store pointer to char that stopped the scan */ + *endptr = p; + + if (flags & FL_NEG) + /* negate result if there was a neg sign */ + number = (unsigned long)(-(long)number); + + return number; /* done. */ +} + +long _CRTAPI1 strtol ( + const char *nptr, + char **endptr, + int ibase + ) +{ + return (long) strtoxl(nptr, endptr, ibase, 0); +} + +unsigned long _CRTAPI1 strtoul ( + const char *nptr, + char **endptr, + int ibase + ) +{ + return strtoxl(nptr, endptr, ibase, FL_UNSIGNED); +} |