nasm/include/nasmlib.h
H. Peter Anvin (Intel) 5bb35772b3 BR 3392597: the system malloc() can return NULL
malloc(0) can legitimately return NULL; it does on some systems and
not others. Force the size to 1 byte if the size is 0 coming in,
except for realloc() where this is legitimate and equivalent to
free().

Since this is an abnormal case, and can't even happen with most C
libraries, handle it on the error path, after we already got back a
NULL pointer.

Reported-by: Ozkan Sezer <sezeroz@gmail.com>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
2019-08-16 00:41:29 -07:00

454 lines
15 KiB
C

/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2018 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*
* ----------------------------------------------------------------------- */
/*
* nasmlib.h header file for nasmlib.c
*/
#ifndef NASM_NASMLIB_H
#define NASM_NASMLIB_H
#include "compiler.h"
#include "bytesex.h"
/*
* Useful construct for private values
*/
union intorptr {
int64_t i;
uint64_t u;
size_t s;
void *p;
const void *cp;
uintptr_t up;
};
typedef union intorptr intorptr;
/*
* Wrappers around malloc, realloc, free and a few more. nasm_malloc
* will fatal-error and die rather than return NULL; nasm_realloc will
* do likewise, and will also guarantee to work right on being passed
* a NULL pointer; nasm_free will do nothing if it is passed a NULL
* pointer.
*/
void * safe_malloc(1) nasm_malloc(size_t);
void * safe_malloc(1) nasm_zalloc(size_t);
void * safe_malloc2(1,2) nasm_calloc(size_t, size_t);
void * safe_realloc(2) nasm_realloc(void *, size_t);
void nasm_free(void *);
char * safe_alloc nasm_strdup(const char *);
char * safe_alloc nasm_strndup(const char *, size_t);
char * safe_alloc nasm_strcat(const char *one, const char *two);
char * safe_alloc end_with_null nasm_strcatn(const char *one, ...);
/*
* nasm_[v]asprintf() are variants of the semi-standard [v]asprintf()
* functions, except that we return the pointer instead of a count.
* The size of the string (including the final NUL!) is available
* by calling nasm_aprintf_size() afterwards.
*
* nasm_[v]axprintf() are similar, but allocates a user-defined amount
* of storage before the string, and returns a pointer to the
* allocated buffer. The value of nasm_aprintf_size() does *not* include
* this additional storage.
*/
char * safe_alloc printf_func(1, 2) nasm_asprintf(const char *fmt, ...);
char * safe_alloc nasm_vasprintf(const char *fmt, va_list ap);
void * safe_alloc printf_func(2, 3) nasm_axprintf(size_t extra, const char *fmt, ...);
void * safe_alloc nasm_vaxprintf(size_t extra, const char *fmt, va_list ap);
/*
* nasm_last_string_len() returns the length of the last string allocated
* by [v]asprintf, nasm_strdup, nasm_strcat, or nasm_strcatn.
*
* nasm_last_string_size() returns the equivalent size including the
* final NUL.
*/
static inline size_t nasm_last_string_len(void)
{
extern size_t _nasm_last_string_size;
return _nasm_last_string_size - 1;
}
static inline size_t nasm_last_string_size(void)
{
extern size_t _nasm_last_string_size;
return _nasm_last_string_size;
}
/* Assert the argument is a pointer without evaluating it */
#define nasm_assert_pointer(p) ((void)sizeof(*(p)))
#define nasm_new(p) ((p) = nasm_zalloc(sizeof(*(p))))
#define nasm_newn(p,n) ((p) = nasm_calloc((n), sizeof(*(p))))
/*
* This is broken on platforms where there are pointers which don't
* match void * in their internal layout. It unfortunately also
* loses any "const" part of the argument, although hopefully the
* compiler will warn in that case.
*/
#define nasm_delete(p) \
do { \
void **_pp = (void **)&(p); \
nasm_assert_pointer(p); \
nasm_free(*_pp); \
*_pp = NULL; \
} while (0)
#define nasm_zero(x) (memset(&(x), 0, sizeof(x)))
#define nasm_zeron(p,n) (memset((p), 0, (n)*sizeof(*(p))))
/*
* Wrappers around fread()/fwrite() which fatal-errors on failure.
* For fread(), only use this if EOF is supposed to be a fatal error!
*/
void nasm_read(void *, size_t, FILE *);
void nasm_write(const void *, size_t, FILE *);
/*
* NASM failure at build time if the argument is false
*/
#ifdef static_assert
# define nasm_static_assert(x) static_assert((x), #x)
#elif defined(HAVE_FUNC_ATTRIBUTE_ERROR) && defined(__OPTIMIZE__)
# define nasm_static_assert(x) \
do { \
if (!(x)) { \
extern void __attribute__((error("assertion " #x " failed"))) \
_nasm_static_fail(void); \
_nasm_static_fail(); \
} \
} while (0)
#else
/* See http://www.drdobbs.com/compile-time-assertions/184401873 */
# define nasm_static_assert(x) \
do { enum { _static_assert_failed = 1/(!!(x)) }; } while (0)
#endif
/*
* conditional static assert, if we know it is possible to determine
* the assert value at compile time. Since if_constant triggers
* pedantic warnings on gcc, turn them off explicitly around this code.
*/
#ifdef static_assert
# define nasm_try_static_assert(x) \
do { \
not_pedantic_start \
static_assert(if_constant(x, true), #x); \
not_pedantic_end \
} while (0)
#elif defined(HAVE_FUNC_ATTRIBUTE_ERROR) && defined(__OPTIMIZE__)
# define nasm_try_static_assert(x) \
do { \
if (!if_constant(x, true)) { \
extern void __attribute__((error("assertion " #x " failed"))) \
_nasm_static_fail(void); \
_nasm_static_fail(); \
} \
} while (0)
#else
# define nasm_try_static_assert(x) ((void)0)
#endif
/*
* NASM assert failure
*/
fatal_func nasm_assert_failed(const char *, int, const char *);
#define nasm_assert(x) \
do { \
nasm_try_static_assert(x); \
if (unlikely(!(x))) \
nasm_assert_failed(__FILE__,__LINE__,#x); \
} while (0)
/* Utility function to generate a string for an invalid enum */
const char *invalid_enum_str(int);
/*
* ANSI doesn't guarantee the presence of `stricmp' or
* `strcasecmp'.
*/
#if defined(HAVE_STRCASECMP)
#define nasm_stricmp strcasecmp
#elif defined(HAVE_STRICMP)
#define nasm_stricmp stricmp
#else
int pure_func nasm_stricmp(const char *, const char *);
#endif
#if defined(HAVE_STRNCASECMP)
#define nasm_strnicmp strncasecmp
#elif defined(HAVE_STRNICMP)
#define nasm_strnicmp strnicmp
#else
int pure_func nasm_strnicmp(const char *, const char *, size_t);
#endif
int pure_func nasm_memicmp(const char *, const char *, size_t);
#if defined(HAVE_STRSEP)
#define nasm_strsep strsep
#else
char *nasm_strsep(char **stringp, const char *delim);
#endif
#ifndef HAVE_DECL_STRNLEN
size_t pure_func strnlen(const char *, size_t);
#endif
/* This returns the numeric value of a given 'digit'; no check for validity */
static inline unsigned int numvalue(unsigned char c)
{
c |= 0x20;
return c >= 'a' ? c - 'a' + 10 : c - '0';
}
/*
* Convert a string into a number, using NASM number rules. Sets
* `*error' to true if an error occurs, and false otherwise.
*/
int64_t readnum(const char *str, bool *error);
/*
* Convert a character constant into a number. Sets
* `*warn' to true if an overflow occurs, and false otherwise.
* str points to and length covers the middle of the string,
* without the quotes.
*/
int64_t readstrnum(char *str, int length, bool *warn);
/*
* seg_alloc: allocate a hitherto unused segment number.
*/
int32_t seg_alloc(void);
/*
* Add/replace or remove an extension to the end of a filename
*/
const char *filename_set_extension(const char *inname, const char *extension);
/*
* Utility macros...
*
* This is a useful #define which I keep meaning to use more often:
* the number of elements of a statically defined array.
*/
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
/*
* List handling
*
* list_for_each - regular iterator over list
* list_for_each_safe - the same but safe against list items removal
* list_last - find the last element in a list
*/
#define list_for_each(pos, head) \
for (pos = head; pos; pos = pos->next)
#define list_for_each_safe(pos, n, head) \
for (pos = head, n = (pos ? pos->next : NULL); pos; \
pos = n, n = (n ? n->next : NULL))
#define list_last(pos, head) \
for (pos = head; pos && pos->next; pos = pos->next) \
;
#define list_reverse(head, prev, next) \
do { \
if (!head || !head->next) \
break; \
prev = NULL; \
while (head) { \
next = head->next; \
head->next = prev; \
prev = head; \
head = next; \
} \
head = prev; \
} while (0)
/*
* Power of 2 align helpers
*/
#undef ALIGN_MASK /* Some BSD flavors define these in system headers */
#undef ALIGN
#define ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask))
#define ALIGN(v, a) ALIGN_MASK(v, (a) - 1)
#define IS_ALIGNED(v, a) (((v) & ((a) - 1)) == 0)
/*
* Routines to write littleendian data to a file
*/
#define fwriteint8_t(d,f) putc(d,f)
void fwriteint16_t(uint16_t data, FILE * fp);
void fwriteint32_t(uint32_t data, FILE * fp);
void fwriteint64_t(uint64_t data, FILE * fp);
void fwriteaddr(uint64_t data, int size, FILE * fp);
/*
* Binary search routine. Returns index into `array' of an entry
* matching `string', or <0 if no match. `array' is taken to
* contain `size' elements.
*
* bsi() is case sensitive, bsii() is case insensitive.
*/
int bsi(const char *string, const char **array, int size);
int bsii(const char *string, const char **array, int size);
/*
* Convenient string processing helper routines
*/
char *nasm_skip_spaces(const char *p);
char *nasm_skip_word(const char *p);
char *nasm_zap_spaces_fwd(char *p);
char *nasm_zap_spaces_rev(char *p);
char *nasm_trim_spaces(char *p);
char *nasm_get_word(char *p, char **tail);
char *nasm_opt_val(char *p, char **opt, char **val);
/*
* Converts a relative pathname rel_path into an absolute path name.
*
* The buffer returned must be freed by the caller
*/
char * safe_alloc nasm_realpath(const char *rel_path);
/*
* Path-splitting and merging functions
*/
char * safe_alloc nasm_dirname(const char *path);
char * safe_alloc nasm_basename(const char *path);
char * safe_alloc nasm_catfile(const char *dir, const char *path);
const char * pure_func prefix_name(int);
/*
* Wrappers around fopen()... for future change to a dedicated structure
*/
enum file_flags {
NF_BINARY = 0x00000000, /* Binary file (default) */
NF_TEXT = 0x00000001, /* Text file */
NF_NONFATAL = 0x00000000, /* Don't die on open failure (default) */
NF_FATAL = 0x00000002, /* Die on open failure */
NF_FORMAP = 0x00000004 /* Intended to use nasm_map_file() */
};
FILE *nasm_open_read(const char *filename, enum file_flags flags);
FILE *nasm_open_write(const char *filename, enum file_flags flags);
/* Probe for existence of a file */
bool nasm_file_exists(const char *filename);
#define ZERO_BUF_SIZE 65536 /* Default value */
#if defined(BUFSIZ) && (BUFSIZ > ZERO_BUF_SIZE)
# undef ZERO_BUF_SIZE
# define ZERO_BUF_SIZE BUFSIZ
#endif
extern const uint8_t zero_buffer[ZERO_BUF_SIZE];
/* Missing fseeko/ftello */
#ifndef HAVE_FSEEKO
# undef off_t /* Just in case it is a macro */
# ifdef HAVE__FSEEKI64
# define fseeko _fseeki64
# define ftello _ftelli64
# define off_t int64_t
# else
# define fseeko fseek
# define ftello ftell
# define off_t long
# endif
#endif
const void *nasm_map_file(FILE *fp, off_t start, off_t len);
void nasm_unmap_file(const void *p, size_t len);
off_t nasm_file_size(FILE *f);
off_t nasm_file_size_by_path(const char *pathname);
bool nasm_file_time(time_t *t, const char *pathname);
void fwritezero(off_t bytes, FILE *fp);
static inline bool const_func overflow_general(int64_t value, int bytes)
{
int sbit;
int64_t vmax, vmin;
if (bytes >= 8)
return false;
sbit = (bytes << 3) - 1;
vmax = ((int64_t)2 << sbit) - 1;
vmin = -((int64_t)2 << sbit);
return value < vmin || value > vmax;
}
static inline bool const_func overflow_signed(int64_t value, int bytes)
{
int sbit;
int64_t vmax, vmin;
if (bytes >= 8)
return false;
sbit = (bytes << 3) - 1;
vmax = ((int64_t)1 << sbit) - 1;
vmin = -((int64_t)1 << sbit);
return value < vmin || value > vmax;
}
static inline bool const_func overflow_unsigned(int64_t value, int bytes)
{
int sbit;
int64_t vmax, vmin;
if (bytes >= 8)
return false;
sbit = (bytes << 3) - 1;
vmax = ((int64_t)2 << sbit) - 1;
vmin = 0;
return value < vmin || value > vmax;
}
static inline int64_t const_func signed_bits(int64_t value, int bits)
{
if (bits < 64) {
value &= ((int64_t)1 << bits) - 1;
if (value & (int64_t)1 << (bits - 1))
value |= (int64_t)((uint64_t)-1 << bits);
}
return value;
}
/* check if value is power of 2 */
#define is_power2(v) ((v) && ((v) & ((v) - 1)) == 0)
#endif