git/git-compat-util.h

#ifndef GIT_COMPAT_UTIL_H
#define GIT_COMPAT_UTIL_H

#define _FILE_OFFSET_BITS 64

#ifndef FLEX_ARRAY
/*
 * See if our compiler is known to support flexible array members.
 */
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
# define FLEX_ARRAY /* empty */
#elif defined(__GNUC__)
# if (__GNUC__ >= 3)
#  define FLEX_ARRAY /* empty */
# else
#  define FLEX_ARRAY 0 /* older GNU extension */
# endif
#endif

/*
 * Otherwise, default to safer but a bit wasteful traditional style
 */
#ifndef FLEX_ARRAY
# define FLEX_ARRAY 1
#endif
#endif

#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))

#ifdef __GNUC__
#define TYPEOF(x) (__typeof__(x))
#else
#define TYPEOF(x)
#endif

#define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (sizeof(x) * 8 - (bits))))
#define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */

/* Approximation of the length of the decimal representation of this type. */
#define decimal_length(x)	((int)(sizeof(x) * 2.56 + 0.5) + 1)

#if !defined(__APPLE__) && !defined(__FreeBSD__)
#define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
#define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
#endif
#define _ALL_SOURCE 1
#define _GNU_SOURCE 1
#define _BSD_SOURCE 1

#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <sys/param.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>
#include <sys/wait.h>
#include <fnmatch.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <utime.h>
#ifndef NO_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <assert.h>
#include <regex.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <pwd.h>
#include <inttypes.h>
#if defined(__CYGWIN__)
#undef _XOPEN_SOURCE
#include <grp.h>
#define _XOPEN_SOURCE 600
#else
#undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
#include <grp.h>
#define _ALL_SOURCE 1
#endif

#ifndef NO_ICONV
#include <iconv.h>
#endif

/* On most systems <limits.h> would have given us this, but
 * not on some systems (e.g. GNU/Hurd).
 */
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif

#ifndef PRIuMAX
#define PRIuMAX "llu"
#endif

#ifdef __GNUC__
#define NORETURN __attribute__((__noreturn__))
#else
#define NORETURN
#ifndef __attribute__
#define __attribute__(x)
#endif
#endif

/* General helper functions */
extern void usage(const char *err) NORETURN;
extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));

extern void set_usage_routine(void (*routine)(const char *err) NORETURN);
extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
extern void set_error_routine(void (*routine)(const char *err, va_list params));
extern void set_warn_routine(void (*routine)(const char *warn, va_list params));

extern int prefixcmp(const char *str, const char *prefix);

#ifdef NO_MMAP

#ifndef PROT_READ
#define PROT_READ 1
#define PROT_WRITE 2
#define MAP_PRIVATE 1
#define MAP_FAILED ((void*)-1)
#endif

#define mmap git_mmap
#define munmap git_munmap
extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
extern int git_munmap(void *start, size_t length);

/* This value must be multiple of (pagesize * 2) */
#define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)

#else /* NO_MMAP */

#include <sys/mman.h>

/* This value must be multiple of (pagesize * 2) */
#define DEFAULT_PACKED_GIT_WINDOW_SIZE \
	(sizeof(void*) >= 8 \
		?  1 * 1024 * 1024 * 1024 \
		: 32 * 1024 * 1024)

#endif /* NO_MMAP */

#define DEFAULT_PACKED_GIT_LIMIT \
	((1024L * 1024L) * (sizeof(void*) >= 8 ? 8192 : 256))

#ifdef NO_PREAD
#define pread git_pread
extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
#endif

#ifdef NO_SETENV
#define setenv gitsetenv
extern int gitsetenv(const char *, const char *, int);
#endif

#ifdef NO_MKDTEMP
#define mkdtemp gitmkdtemp
extern char *gitmkdtemp(char *);
#endif

#ifdef NO_UNSETENV
#define unsetenv gitunsetenv
extern void gitunsetenv(const char *);
#endif

#ifdef NO_STRCASESTR
#define strcasestr gitstrcasestr
extern char *gitstrcasestr(const char *haystack, const char *needle);
#endif

#ifdef NO_STRLCPY
#define strlcpy gitstrlcpy
extern size_t gitstrlcpy(char *, const char *, size_t);
#endif

#ifdef NO_STRTOUMAX
#define strtoumax gitstrtoumax
extern uintmax_t gitstrtoumax(const char *, char **, int);
#endif

#ifdef NO_HSTRERROR
#define hstrerror githstrerror
extern const char *githstrerror(int herror);
#endif

#ifdef NO_MEMMEM
#define memmem gitmemmem
void *gitmemmem(const void *haystack, size_t haystacklen,
                const void *needle, size_t needlelen);
#endif

#ifdef FREAD_READS_DIRECTORIES
#define fopen(a,b) git_fopen(a,b)
extern FILE *git_fopen(const char*, const char*);
#endif

#ifdef SNPRINTF_RETURNS_BOGUS
#define snprintf git_snprintf
extern int git_snprintf(char *str, size_t maxsize,
			const char *format, ...);
#define vsnprintf git_vsnprintf
extern int git_vsnprintf(char *str, size_t maxsize,
			 const char *format, va_list ap);
#endif

#ifdef __GLIBC_PREREQ
#if __GLIBC_PREREQ(2, 1)
#define HAVE_STRCHRNUL
#endif
#endif

#ifndef HAVE_STRCHRNUL
#define strchrnul gitstrchrnul
static inline char *gitstrchrnul(const char *s, int c)
{
	while (*s && *s != c)
		s++;
	return (char *)s;
}
#endif

extern void release_pack_memory(size_t, int);

static inline char* xstrdup(const char *str)
{
	char *ret = strdup(str);
	if (!ret) {
		release_pack_memory(strlen(str) + 1, -1);
		ret = strdup(str);
		if (!ret)
			die("Out of memory, strdup failed");
	}
	return ret;
}

static inline void *xmalloc(size_t size)
{
	void *ret = malloc(size);
	if (!ret && !size)
		ret = malloc(1);
	if (!ret) {
		release_pack_memory(size, -1);
		ret = malloc(size);
		if (!ret && !size)
			ret = malloc(1);
		if (!ret)
			die("Out of memory, malloc failed");
	}
#ifdef XMALLOC_POISON
	memset(ret, 0xA5, size);
#endif
	return ret;
}

/*
 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
 * "data" to the allocated memory, zero terminates the allocated memory,
 * and returns a pointer to the allocated memory. If the allocation fails,
 * the program dies.
 */
static inline void *xmemdupz(const void *data, size_t len)
{
	char *p = xmalloc(len + 1);
	memcpy(p, data, len);
	p[len] = '\0';
	return p;
}

static inline char *xstrndup(const char *str, size_t len)
{
	char *p = memchr(str, '\0', len);
	return xmemdupz(str, p ? p - str : len);
}

static inline void *xrealloc(void *ptr, size_t size)
{
	void *ret = realloc(ptr, size);
	if (!ret && !size)
		ret = realloc(ptr, 1);
	if (!ret) {
		release_pack_memory(size, -1);
		ret = realloc(ptr, size);
		if (!ret && !size)
			ret = realloc(ptr, 1);
		if (!ret)
			die("Out of memory, realloc failed");
	}
	return ret;
}

static inline void *xcalloc(size_t nmemb, size_t size)
{
	void *ret = calloc(nmemb, size);
	if (!ret && (!nmemb || !size))
		ret = calloc(1, 1);
	if (!ret) {
		release_pack_memory(nmemb * size, -1);
		ret = calloc(nmemb, size);
		if (!ret && (!nmemb || !size))
			ret = calloc(1, 1);
		if (!ret)
			die("Out of memory, calloc failed");
	}
	return ret;
}

static inline void *xmmap(void *start, size_t length,
	int prot, int flags, int fd, off_t offset)
{
	void *ret = mmap(start, length, prot, flags, fd, offset);
	if (ret == MAP_FAILED) {
		if (!length)
			return NULL;
		release_pack_memory(length, fd);
		ret = mmap(start, length, prot, flags, fd, offset);
		if (ret == MAP_FAILED)
			die("Out of memory? mmap failed: %s", strerror(errno));
	}
	return ret;
}

/*
 * xread() is the same a read(), but it automatically restarts read()
 * operations with a recoverable error (EAGAIN and EINTR). xread()
 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
 */
static inline ssize_t xread(int fd, void *buf, size_t len)
{
	ssize_t nr;
	while (1) {
		nr = read(fd, buf, len);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

/*
 * xwrite() is the same a write(), but it automatically restarts write()
 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
 * GUARANTEE that "len" bytes is written even if the operation is successful.
 */
static inline ssize_t xwrite(int fd, const void *buf, size_t len)
{
	ssize_t nr;
	while (1) {
		nr = write(fd, buf, len);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

static inline int xdup(int fd)
{
	int ret = dup(fd);
	if (ret < 0)
		die("dup failed: %s", strerror(errno));
	return ret;
}

static inline FILE *xfdopen(int fd, const char *mode)
{
	FILE *stream = fdopen(fd, mode);
	if (stream == NULL)
		die("Out of memory? fdopen failed: %s", strerror(errno));
	return stream;
}

static inline int xmkstemp(char *template)
{
	int fd;

	fd = mkstemp(template);
	if (fd < 0)
		die("Unable to create temporary file: %s", strerror(errno));
	return fd;
}

static inline size_t xsize_t(off_t len)
{
	return (size_t)len;
}

static inline int has_extension(const char *filename, const char *ext)
{
	size_t len = strlen(filename);
	size_t extlen = strlen(ext);
	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
}

/* Sane ctype - no locale, and works with signed chars */
#undef isspace
#undef isdigit
#undef isalpha
#undef isalnum
#undef tolower
#undef toupper
extern unsigned char sane_ctype[256];
#define GIT_SPACE 0x01
#define GIT_DIGIT 0x02
#define GIT_ALPHA 0x04
#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
#define isspace(x) sane_istest(x,GIT_SPACE)
#define isdigit(x) sane_istest(x,GIT_DIGIT)
#define isalpha(x) sane_istest(x,GIT_ALPHA)
#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
#define tolower(x) sane_case((unsigned char)(x), 0x20)
#define toupper(x) sane_case((unsigned char)(x), 0)

static inline int sane_case(int x, int high)
{
	if (sane_istest(x, GIT_ALPHA))
		x = (x & ~0x20) | high;
	return x;
}

static inline int strtoul_ui(char const *s, int base, unsigned int *result)
{
	unsigned long ul;
	char *p;

	errno = 0;
	ul = strtoul(s, &p, base);
	if (errno || *p || p == s || (unsigned int) ul != ul)
		return -1;
	*result = ul;
	return 0;
}

static inline int strtol_i(char const *s, int base, int *result)
{
	long ul;
	char *p;

	errno = 0;
	ul = strtol(s, &p, base);
	if (errno || *p || p == s || (int) ul != ul)
		return -1;
	*result = ul;
	return 0;
}

#ifdef INTERNAL_QSORT
void git_qsort(void *base, size_t nmemb, size_t size,
	       int(*compar)(const void *, const void *));
#define qsort git_qsort
#endif

#ifndef DIR_HAS_BSD_GROUP_SEMANTICS
# define FORCE_DIR_SET_GID S_ISGID
#else
# define FORCE_DIR_SET_GID 0
#endif

#endif