8073c40477
Yahoo!'s mailer delivered the report about nowrap_add() to my spam folder, apparently because it thinks that the signature attachments "may contain harmful content". :-( nowrap_add() checks for signed overflow after the fact, so after undefined behavior if that happens. This rewrites nowrap_add() and moves it from end.c to integer.h. I haven't generated any values big enough to exercise it, but the algorithm is straightforward so I'll take it on faith.
119 lines
4.1 KiB
C
119 lines
4.1 KiB
C
/* NetHack 3.7 integer.h $NHDT-Date: 1720397754 2024/07/08 00:15:54 $ $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.13 $ */
|
|
/* Copyright (c) 2016 by Michael Allison */
|
|
/* NetHack may be freely redistributed. See license for details. */
|
|
|
|
/* integer.h -- provide sized integer types
|
|
*
|
|
* We try to sort out a way to provide sized integer types
|
|
* in here. The strong preference is to try to let a
|
|
* compiler-supplied header file set up the types.
|
|
*
|
|
* If your compiler is C99 conforming and sets a value of
|
|
* __STDC_VERSION__ >= 199901L, then <stdint.h> is supposed
|
|
* to be available for inclusion.
|
|
*
|
|
* If your compiler doesn't set __STDC_VERSION__ to indicate
|
|
* full conformance to C99, but does actually supply a suitable
|
|
* <stdint.h>, you can pass a compiler flag -DHAS_STDINT_H
|
|
* during build to cause the inclusion of <stdint.h> anyway.
|
|
*
|
|
* If <stdint.h> doesn't get included, then the code in the
|
|
* STDINT_WORKAROUND section of code is not skipped and will
|
|
* be used to set up the types.
|
|
*
|
|
* We acknowledge that some ongoing maintenance may be needed
|
|
* over time if people send us code updates for making the
|
|
* determination of whether <stdint.h> is available, or
|
|
* require adjustments to the base type used for some
|
|
* compiler/platform combinations.
|
|
*
|
|
*/
|
|
|
|
#ifndef INTEGER_H
|
|
#define INTEGER_H
|
|
|
|
/* DEC C (aka Compaq C for a while, HP C these days) for VMS is
|
|
classified as a freestanding implementation rather than a hosted one
|
|
and even though it claims to be C99, it does not provide <stdint.h>. */
|
|
#if defined(__DECC) && defined(VMS) && !defined(HAS_STDINT_H)
|
|
#define HAS_INTTYPES_H
|
|
#else /*!__DECC*/
|
|
|
|
#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) \
|
|
&& !defined(HAS_STDINT_H)
|
|
/* The compiler claims to conform to C99. Use stdint.h */
|
|
#define HAS_STDINT_H
|
|
#endif
|
|
#if defined(__GNUC__) && defined(__INT64_MAX__) && !defined(HAS_STDINT_H)
|
|
#define HAS_STDINT_H
|
|
#endif
|
|
|
|
#endif /*?__DECC*/
|
|
|
|
#ifdef HAS_STDINT_H
|
|
#include <stdint.h>
|
|
#define SKIP_STDINT_WORKAROUND
|
|
#else /*!stdint*/
|
|
#ifdef HAS_INTTYPES_H
|
|
#include <inttypes.h>
|
|
#define SKIP_STDINT_WORKAROUND
|
|
#endif
|
|
#endif /*?stdint*/
|
|
|
|
#ifndef SKIP_STDINT_WORKAROUND /* !C99 */
|
|
/*
|
|
* STDINT_WORKAROUND section begins here
|
|
*/
|
|
typedef signed char int8_t;
|
|
typedef unsigned char uint8_t;
|
|
typedef short int16_t;
|
|
typedef unsigned short uint16_t;
|
|
|
|
#if defined(__WATCOMC__) && !defined(__386__)
|
|
/* Open Watcom providing a 16 bit build for MS-DOS or OS/2 */
|
|
/* int is 16 bits; use long for 32 bits */
|
|
typedef long int int32_t;
|
|
typedef unsigned long int uint32_t;
|
|
#else
|
|
/* Otherwise, assume either a 32- or 64-bit compiler */
|
|
/* long may be 64 bits; use int for 32 bits */
|
|
typedef int int32_t;
|
|
typedef unsigned int uint32_t;
|
|
#endif
|
|
|
|
/* The only place where nethack cares about 64-bit integers is in the
|
|
Isaac64 random number generator. If your environment can't support
|
|
64-bit integers, you should comment out USE_ISAAC64 in config.h so
|
|
that the previous RNG gets used instead. Then this file will be
|
|
inhibited and it won't matter what the int64_t and uint64_t lines are. */
|
|
typedef long long int int64_t;
|
|
typedef unsigned long long int uint64_t;
|
|
|
|
#endif /* !C99 */
|
|
|
|
/* Provide int8, uint8, int16, uint16, int32, uint32, int64 and uint64 */
|
|
typedef int8_t int8;
|
|
typedef uint8_t uint8;
|
|
typedef int16_t int16;
|
|
typedef uint16_t uint16;
|
|
typedef int32_t int32;
|
|
typedef uint32_t uint32;
|
|
typedef int64_t int64;
|
|
typedef uint64_t uint64;
|
|
|
|
/* for non-negative L, calculate L * 10 + D, avoiding signed overflow;
|
|
yields -1 if overflow would have happened;
|
|
assumes compiler will optimize the constants */
|
|
#define AppendLongDigit(L,D) \
|
|
(((L) < LONG_MAX / 10L \
|
|
|| ((L) == LONG_MAX / 10L && (D) <= LONG_MAX % 10L)) \
|
|
? (L) * 10L + (D) \
|
|
: -1L)
|
|
|
|
/* add a and b, return max long value if overflow would have occurred;
|
|
assumes that both a and b are non-negative; caller should apply
|
|
cast(s) to (long) in the arguments if any are needed */
|
|
#define nowrap_add(a,b) ((a) <= (LONG_MAX - (b)) ? ((a) + (b)) : LONG_MAX)
|
|
|
|
#endif /* INTEGER_H */
|