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git/git-compat-util.h

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#ifndef GIT_COMPAT_UTIL_H
#define GIT_COMPAT_UTIL_H
#if __STDC_VERSION__ - 0 < 199901L
/*
* Git is in a testing period for mandatory C99 support in the compiler. If
* your compiler is reasonably recent, you can try to enable C99 support (or,
* for MSVC, C11 support). If you encounter a problem and can't enable C99
* support with your compiler (such as with "-std=gnu99") and don't have access
* to one with this support, such as GCC or Clang, you can remove this #if
* directive, but please report the details of your system to
* git@vger.kernel.org.
*/
#error "Required C99 support is in a test phase. Please see git-compat-util.h for more details."
#endif
#ifdef USE_MSVC_CRTDBG
/*
* For these to work they must appear very early in each
* file -- before most of the standard header files.
*/
#include <stdlib.h>
#include <crtdbg.h>
#endif
#include "compat/posix.h"
struct strbuf;
#if defined(__GNUC__) || defined(__clang__)
# define PRAGMA(pragma) _Pragma(#pragma)
# define DISABLE_WARNING(warning) PRAGMA(GCC diagnostic ignored #warning)
#else
# define DISABLE_WARNING(warning)
#endif
#ifdef DISABLE_SIGN_COMPARE_WARNINGS
DISABLE_WARNING(-Wsign-compare)
#endif
#ifndef FLEX_ARRAY
/*
* See if our compiler is known to support flexible array members.
*/
/*
* Check vendor specific quirks first, before checking the
* __STDC_VERSION__, as vendor compilers can lie and we need to be
* able to work them around. Note that by not defining FLEX_ARRAY
* here, we can fall back to use the "safer but a bit wasteful" one
* later.
*/
#if defined(__SUNPRO_C) && (__SUNPRO_C <= 0x580)
#elif defined(__GNUC__)
# if (__GNUC__ >= 3)
# define FLEX_ARRAY /* empty */
# else
# define FLEX_ARRAY 0 /* older GNU extension */
# endif
#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
# define FLEX_ARRAY /* empty */
#endif
/*
* Otherwise, default to safer but a bit wasteful traditional style
*/
#ifndef FLEX_ARRAY
# define FLEX_ARRAY 1
#endif
#endif
/*
* BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
* @cond: the compile-time condition which must be true.
*
* Your compile will fail if the condition isn't true, or can't be evaluated
* by the compiler. This can be used in an expression: its value is "0".
*
* Example:
* #define foo_to_char(foo) \
* ((char *)(foo) \
* + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
*/
#define BUILD_ASSERT_OR_ZERO(cond) \
(sizeof(char [1 - 2*!(cond)]) - 1)
#if GIT_GNUC_PREREQ(3, 1)
/* &arr[0] degrades to a pointer: a different type from an array */
# define BARF_UNLESS_AN_ARRAY(arr) \
BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(__typeof__(arr), \
__typeof__(&(arr)[0])))
# define BARF_UNLESS_COPYABLE(dst, src) \
BUILD_ASSERT_OR_ZERO(__builtin_types_compatible_p(__typeof__(*(dst)), \
__typeof__(*(src))))
# define BARF_UNLESS_SIGNED(var) BUILD_ASSERT_OR_ZERO(((__typeof__(var)) -1) < 0)
# define BARF_UNLESS_UNSIGNED(var) BUILD_ASSERT_OR_ZERO(((__typeof__(var)) -1) > 0)
#else
# define BARF_UNLESS_AN_ARRAY(arr) 0
# define BARF_UNLESS_COPYABLE(dst, src) \
BUILD_ASSERT_OR_ZERO(0 ? ((*(dst) = *(src)), 0) : \
sizeof(*(dst)) == sizeof(*(src)))
# define BARF_UNLESS_SIGNED(var) 0
# define BARF_UNLESS_UNSIGNED(var) 0
#endif
/*
* ARRAY_SIZE - get the number of elements in a visible array
* @x: the array whose size you want.
*
* This does not work on pointers, or arrays declared as [], or
* function parameters. With correct compiler support, such usage
* will cause a build error (see the build_assert_or_zero macro).
*/
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
#define bitsizeof(x) (CHAR_BIT * sizeof(x))
#define maximum_signed_value_of_type(a) \
(INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
#define maximum_unsigned_value_of_type(a) \
(UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
/*
* Signed integer overflow is undefined in C, so here's a helper macro
* to detect if the sum of two integers will overflow.
*
* Requires: a >= 0, typeof(a) equals typeof(b)
*/
#define signed_add_overflows(a, b) \
((b) > maximum_signed_value_of_type(a) - (a))
#define unsigned_add_overflows(a, b) \
((b) > maximum_unsigned_value_of_type(a) - (a))
/*
* Returns true if the multiplication of "a" and "b" will
* overflow. The types of "a" and "b" must match and must be unsigned.
* Note that this macro evaluates "a" twice!
*/
#define unsigned_mult_overflows(a, b) \
((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
/*
* Returns true if the left shift of "a" by "shift" bits will
* overflow. The type of "a" must be unsigned.
*/
#define unsigned_left_shift_overflows(a, shift) \
((shift) < bitsizeof(a) && \
(a) > maximum_unsigned_value_of_type(a) >> (shift))
#ifdef __GNUC__
#define TYPEOF(x) (__typeof__(x))
#else
#define TYPEOF(x)
#endif
#define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (bitsizeof(x) - (bits))))
#define HAS_MULTI_BITS(i) ((i) & ((i) - 1)) /* checks if an integer has more than 1 bit set */
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
/* 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(NO_UNIX_SOCKETS) || !defined(GIT_WINDOWS_NATIVE)
static inline int _have_unix_sockets(void)
{
#if defined(NO_UNIX_SOCKETS)
return 0;
#else
return 1;
#endif
}
#define have_unix_sockets _have_unix_sockets
#endif
/* Used by compat/win32/path-utils.h, and more */
static inline int is_xplatform_dir_sep(int c)
{
return c == '/' || c == '\\';
}
#if defined(__CYGWIN__)
#include "compat/win32/path-utils.h"
#endif
#if defined(__MINGW32__)
/* pull in Windows compatibility stuff */
#include "compat/win32/path-utils.h"
#include "compat/mingw.h"
#elif defined(_MSC_VER)
#include "compat/win32/path-utils.h"
#include "compat/msvc.h"
#endif
/* used on Mac OS X */
#ifdef PRECOMPOSE_UNICODE
#include "compat/precompose_utf8.h"
#else
static inline const char *precompose_argv_prefix(int argc UNUSED,
const char **argv UNUSED,
const char *prefix)
{
return prefix;
}
static inline const char *precompose_string_if_needed(const char *in)
{
return in;
}
#define probe_utf8_pathname_composition()
#endif
#ifndef NO_OPENSSL
#ifdef __APPLE__
#undef __AVAILABILITY_MACROS_USES_AVAILABILITY
#define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
#include <AvailabilityMacros.h>
#undef DEPRECATED_ATTRIBUTE
#define DEPRECATED_ATTRIBUTE
#undef __AVAILABILITY_MACROS_USES_AVAILABILITY
#endif
#include <openssl/ssl.h>
#include <openssl/err.h>
#endif
#ifdef HAVE_SYSINFO
# include <sys/sysinfo.h>
#endif
#ifndef PATH_SEP
#define PATH_SEP ':'
#endif
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
#ifndef _PATH_DEFPATH
#define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
#endif
#ifndef platform_core_config
struct config_context;
static inline int noop_core_config(const char *var UNUSED,
const char *value UNUSED,
const struct config_context *ctx UNUSED,
void *cb UNUSED)
{
return 0;
}
#define platform_core_config noop_core_config
#endif
#ifndef has_dos_drive_prefix
static inline int git_has_dos_drive_prefix(const char *path UNUSED)
{
return 0;
}
#define has_dos_drive_prefix git_has_dos_drive_prefix
#endif
#ifndef skip_dos_drive_prefix
static inline int git_skip_dos_drive_prefix(char **path UNUSED)
{
return 0;
}
#define skip_dos_drive_prefix git_skip_dos_drive_prefix
#endif
static inline int git_is_dir_sep(int c)
{
return c == '/';
}
#ifndef is_dir_sep
#define is_dir_sep git_is_dir_sep
#endif
#ifndef offset_1st_component
static inline int git_offset_1st_component(const char *path)
{
return is_dir_sep(path[0]);
}
#define offset_1st_component git_offset_1st_component
#endif
#ifndef fspathcmp
#define fspathcmp git_fspathcmp
#endif
#ifndef fspathncmp
#define fspathncmp git_fspathncmp
#endif
#ifndef is_valid_path
#define is_valid_path(path) 1
#endif
#ifndef is_path_owned_by_current_user
#ifdef __TANDEM
#define ROOT_UID 65535
#else
#define ROOT_UID 0
#endif
/*
* Do not use this function when
* (1) geteuid() did not say we are running as 'root', or
* (2) using this function will compromise the system.
*
* PORTABILITY WARNING:
* This code assumes uid_t is unsigned because that is what sudo does.
* If your uid_t type is signed and all your ids are positive then it
* should all work fine.
* If your version of sudo uses negative values for uid_t or it is
* buggy and return an overflowed value in SUDO_UID, then git might
* fail to grant access to your repository properly or even mistakenly
* grant access to someone else.
* In the unlikely scenario this happened to you, and that is how you
* got to this message, we would like to know about it; so sent us an
* email to git@vger.kernel.org indicating which platform you are
* using and which version of sudo, so we can improve this logic and
* maybe provide you with a patch that would prevent this issue again
* in the future.
*/
static inline void extract_id_from_env(const char *env, uid_t *id)
{
const char *real_uid = getenv(env);
/* discard anything empty to avoid a more complex check below */
if (real_uid && *real_uid) {
char *endptr = NULL;
unsigned long env_id;
errno = 0;
/* silent overflow errors could trigger a bug here */
env_id = strtoul(real_uid, &endptr, 10);
if (!*endptr && !errno)
*id = env_id;
}
}
static inline int is_path_owned_by_current_uid(const char *path,
struct strbuf *report UNUSED)
{
struct stat st;
uid_t euid;
if (lstat(path, &st))
return 0;
euid = geteuid();
if (euid == ROOT_UID)
{
if (st.st_uid == ROOT_UID)
return 1;
else
extract_id_from_env("SUDO_UID", &euid);
}
return st.st_uid == euid;
}
#define is_path_owned_by_current_user is_path_owned_by_current_uid
#endif
#ifndef find_last_dir_sep
static inline char *git_find_last_dir_sep(const char *path)
{
return strrchr(path, '/');
}
#define find_last_dir_sep git_find_last_dir_sep
#endif
#ifndef has_dir_sep
static inline int git_has_dir_sep(const char *path)
{
return !!strchr(path, '/');
}
#define has_dir_sep(path) git_has_dir_sep(path)
#endif
#ifndef query_user_email
#define query_user_email() NULL
#endif
#ifdef __TANDEM
#include <floss.h(floss_execl,floss_execlp,floss_execv,floss_execvp)>
#include <floss.h(floss_getpwuid)>
#ifndef NSIG
/*
* NonStop NSE and NSX do not provide NSIG. SIGGUARDIAN(99) is the highest
* known, by detective work using kill -l as a list is all signals
* instead of signal.h where it should be.
*/
# define NSIG 100
#endif
#endif
#if defined(__HP_cc) && (__HP_cc >= 61000)
#define NORETURN __attribute__((noreturn))
#define NORETURN_PTR
#elif defined(__GNUC__) && !defined(NO_NORETURN)
#define NORETURN __attribute__((__noreturn__))
#define NORETURN_PTR __attribute__((__noreturn__))
#elif defined(_MSC_VER)
#define NORETURN __declspec(noreturn)
#define NORETURN_PTR
#else
#define NORETURN
#define NORETURN_PTR
#ifndef __GNUC__
#ifndef __attribute__
#define __attribute__(x)
#endif
#endif
#endif
/* The sentinel attribute is valid from gcc version 4.0 */
#if defined(__GNUC__) && (__GNUC__ >= 4)
#define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
/* warn_unused_result exists as of gcc 3.4.0, but be lazy and check 4.0 */
#define RESULT_MUST_BE_USED __attribute__ ((warn_unused_result))
#else
#define LAST_ARG_MUST_BE_NULL
#define RESULT_MUST_BE_USED
#endif
/*
* MAYBE_UNUSED marks a function parameter that may be unused, but
* whose use is not an error. It also can be used to annotate a
* function, a variable, or a type that may be unused.
*
* Depending on a configuration, all uses of such a thing may become
* #ifdef'ed away. Marking it with UNUSED would give a warning in a
* compilation where it is indeed used, and not marking it at all
* would give a warning in a compilation where it is unused. In such
* a case, MAYBE_UNUSED is the appropriate annotation to use.
*/
#define MAYBE_UNUSED __attribute__((__unused__))
#include "compat/bswap.h"
#include "wrapper.h"
/* General helper functions */
NORETURN void usage(const char *err);
NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
int die_message(const char *err, ...) __attribute__((format (printf, 1, 2)));
int die_message_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
void show_usage_if_asked(int ac, const char **av, const char *err);
NORETURN void you_still_use_that(const char *command_name);
#ifndef NO_OPENSSL
#ifdef APPLE_COMMON_CRYPTO
#include "compat/apple-common-crypto.h"
#else
#include <openssl/evp.h>
#include <openssl/hmac.h>
#endif /* APPLE_COMMON_CRYPTO */
#include <openssl/x509v3.h>
#endif /* NO_OPENSSL */
#ifdef HAVE_OPENSSL_CSPRNG
#include <openssl/rand.h>
#endif
/*
* Let callers be aware of the constant return value; this can help
* gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
* because other compilers may be confused by this.
*/
#if defined(__GNUC__)
static inline int const_error(void)
{
return -1;
}
#define error(...) (error(__VA_ARGS__), const_error())
#define error_errno(...) (error_errno(__VA_ARGS__), const_error())
#endif
typedef void (*report_fn)(const char *, va_list params);
void set_die_routine(NORETURN_PTR report_fn routine);
report_fn get_die_message_routine(void);
void set_error_routine(report_fn routine);
report_fn get_error_routine(void);
void set_warn_routine(report_fn routine);
report_fn get_warn_routine(void);
void set_die_is_recursing_routine(int (*routine)(void));
/*
* If the string "str" begins with the string found in "prefix", return true.
* The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
* the string right after the prefix).
*
* Otherwise, return false and leave "out" untouched.
*
* Examples:
*
* [extract branch name, fail if not a branch]
* if (!skip_prefix(ref, "refs/heads/", &branch)
* return -1;
*
* [skip prefix if present, otherwise use whole string]
* skip_prefix(name, "refs/heads/", &name);
*/
static inline bool skip_prefix(const char *str, const char *prefix,
const char **out)
{
do {
if (!*prefix) {
*out = str;
return true;
}
} while (*str++ == *prefix++);
return false;
}
/*
* Like skip_prefix, but promises never to read past "len" bytes of the input
* buffer, and returns the remaining number of bytes in "out" via "outlen".
*/
static inline bool skip_prefix_mem(const char *buf, size_t len,
const char *prefix,
const char **out, size_t *outlen)
{
size_t prefix_len = strlen(prefix);
if (prefix_len <= len && !memcmp(buf, prefix, prefix_len)) {
*out = buf + prefix_len;
*outlen = len - prefix_len;
return true;
}
return false;
}
/*
* If buf ends with suffix, return true and subtract the length of the suffix
* from *len. Otherwise, return false and leave *len untouched.
*/
static inline bool strip_suffix_mem(const char *buf, size_t *len,
const char *suffix)
{
size_t suflen = strlen(suffix);
if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
return false;
*len -= suflen;
return true;
}
/*
* If str ends with suffix, return true and set *len to the size of the string
* without the suffix. Otherwise, return false and set *len to the size of the
* string.
*
* Note that we do _not_ NUL-terminate str to the new length.
*/
static inline bool strip_suffix(const char *str, const char *suffix,
size_t *len)
{
*len = strlen(str);
return strip_suffix_mem(str, len, suffix);
}
#define SWAP(a, b) do { \
void *_swap_a_ptr = &(a); \
void *_swap_b_ptr = &(b); \
unsigned char _swap_buffer[sizeof(a)]; \
memcpy(_swap_buffer, _swap_a_ptr, sizeof(a)); \
memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a) + \
BUILD_ASSERT_OR_ZERO(sizeof(a) == sizeof(b))); \
memcpy(_swap_b_ptr, _swap_buffer, sizeof(a)); \
} while (0)
#ifdef NO_MMAP
/* This value must be multiple of (pagesize * 2) */
#define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
#else /* NO_MMAP */
/* 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 */
#ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
#define on_disk_bytes(st) ((st).st_size)
#else
#define on_disk_bytes(st) ((st).st_blocks * 512)
#endif
#define DEFAULT_PACKED_GIT_LIMIT \
((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? (32 * 1024L * 1024L) : 256))
int git_open_cloexec(const char *name, int flags);
#define git_open(name) git_open_cloexec(name, O_RDONLY)
static inline size_t st_add(size_t a, size_t b)
{
if (unsigned_add_overflows(a, b))
die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
(uintmax_t)a, (uintmax_t)b);
return a + b;
}
#define st_add3(a,b,c) st_add(st_add((a),(b)),(c))
#define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
static inline size_t st_mult(size_t a, size_t b)
{
if (unsigned_mult_overflows(a, b))
die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
(uintmax_t)a, (uintmax_t)b);
return a * b;
}
static inline size_t st_sub(size_t a, size_t b)
{
if (a < b)
die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
(uintmax_t)a, (uintmax_t)b);
return a - b;
}
static inline size_t st_left_shift(size_t a, unsigned shift)
{
if (unsigned_left_shift_overflows(a, shift))
die("size_t overflow: %"PRIuMAX" << %u",
(uintmax_t)a, shift);
return a << shift;
}
static inline unsigned long cast_size_t_to_ulong(size_t a)
{
if (a != (unsigned long)a)
die("object too large to read on this platform: %"
PRIuMAX" is cut off to %lu",
(uintmax_t)a, (unsigned long)a);
return (unsigned long)a;
}
static inline uint32_t cast_size_t_to_uint32_t(size_t a)
{
if (a != (uint32_t)a)
die("object too large to read on this platform: %"
PRIuMAX" is cut off to %u",
(uintmax_t)a, (uint32_t)a);
return (uint32_t)a;
}
static inline int cast_size_t_to_int(size_t a)
{
if (a > INT_MAX)
die("number too large to represent as int on this platform: %"PRIuMAX,
(uintmax_t)a);
return (int)a;
}
static inline uint64_t u64_mult(uint64_t a, uint64_t b)
{
if (unsigned_mult_overflows(a, b))
die("uint64_t overflow: %"PRIuMAX" * %"PRIuMAX,
(uintmax_t)a, (uintmax_t)b);
return a * b;
}
static inline uint64_t u64_add(uint64_t a, uint64_t b)
{
if (unsigned_add_overflows(a, b))
die("uint64_t overflow: %"PRIuMAX" + %"PRIuMAX,
(uintmax_t)a, (uintmax_t)b);
return a + b;
}
/*
* Limit size of IO chunks, because huge chunks only cause pain. OS X
* 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
* the absence of bugs, large chunks can result in bad latencies when
* you decide to kill the process.
*
* We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
* that is smaller than that, clip it to SSIZE_MAX, as a call to
* read(2) or write(2) larger than that is allowed to fail. As the last
* resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
* to override this, if the definition of SSIZE_MAX given by the platform
* is broken.
*/
#ifndef MAX_IO_SIZE
# define MAX_IO_SIZE_DEFAULT (8*1024*1024)
# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
# define MAX_IO_SIZE SSIZE_MAX
# else
# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
# endif
#endif
#ifdef HAVE_ALLOCA_H
# include <alloca.h>
# define xalloca(size) (alloca(size))
# define xalloca_free(p) do {} while (0)
#else
# define xalloca(size) (xmalloc(size))
# define xalloca_free(p) (free(p))
#endif
/*
* FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
* that ptr is used twice, so don't pass e.g. ptr++.
*/
#define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
#define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
#define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)))
#define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
#define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
BARF_UNLESS_COPYABLE((dst), (src)))
static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
{
if (n)
memcpy(dst, src, st_mult(size, n));
}
#define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
BARF_UNLESS_COPYABLE((dst), (src)))
static inline void move_array(void *dst, const void *src, size_t n, size_t size)
{
if (n)
memmove(dst, src, st_mult(size, n));
}
#define DUP_ARRAY(dst, src, n) do { \
size_t dup_array_n_ = (n); \
COPY_ARRAY(ALLOC_ARRAY((dst), dup_array_n_), (src), dup_array_n_); \
} while (0)
/*
* These functions help you allocate structs with flex arrays, and copy
* the data directly into the array. For example, if you had:
*
* struct foo {
* int bar;
* char name[FLEX_ARRAY];
* };
*
* you can do:
*
* struct foo *f;
* FLEX_ALLOC_MEM(f, name, src, len);
*
* to allocate a "foo" with the contents of "src" in the "name" field.
* The resulting struct is automatically zero'd, and the flex-array field
* is NUL-terminated (whether the incoming src buffer was or not).
*
* The FLEXPTR_* variants operate on structs that don't use flex-arrays,
* but do want to store a pointer to some extra data in the same allocated
* block. For example, if you have:
*
* struct foo {
* char *name;
* int bar;
* };
*
* you can do:
*
* struct foo *f;
* FLEXPTR_ALLOC_STR(f, name, src);
*
* and "name" will point to a block of memory after the struct, which will be
* freed along with the struct (but the pointer can be repointed anywhere).
*
* The *_STR variants accept a string parameter rather than a ptr/len
* combination.
*
* Note that these macros will evaluate the first parameter multiple
* times, and it must be assignable as an lvalue.
*/
#define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
size_t flex_array_len_ = (len); \
(x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
memcpy((void *)(x)->flexname, (buf), flex_array_len_); \
} while (0)
#define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
size_t flex_array_len_ = (len); \
(x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
memcpy((x) + 1, (buf), flex_array_len_); \
(x)->ptrname = (void *)((x)+1); \
} while(0)
#define FLEX_ALLOC_STR(x, flexname, str) \
FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
#define FLEXPTR_ALLOC_STR(x, ptrname, str) \
FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
#define alloc_nr(x) (((x)+16)*3/2)
/**
* Dynamically growing an array using realloc() is error prone and boring.
*
* Define your array with:
*
* - a pointer (`item`) that points at the array, initialized to `NULL`
* (although please name the variable based on its contents, not on its
* type);
*
* - an integer variable (`alloc`) that keeps track of how big the current
* allocation is, initialized to `0`;
*
* - another integer variable (`nr`) to keep track of how many elements the
* array currently has, initialized to `0`.
*
* Then before adding `n`th element to the item, call `ALLOC_GROW(item, n,
* alloc)`. This ensures that the array can hold at least `n` elements by
* calling `realloc(3)` and adjusting `alloc` variable.
*
* ------------
* sometype *item;
* size_t nr;
* size_t alloc
*
* for (i = 0; i < nr; i++)
* if (we like item[i] already)
* return;
*
* // we did not like any existing one, so add one
* ALLOC_GROW(item, nr + 1, alloc);
* item[nr++] = value you like;
* ------------
*
* You are responsible for updating the `nr` variable.
*
* If you need to specify the number of elements to allocate explicitly
* then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`.
*
* Consider using ALLOC_GROW_BY instead of ALLOC_GROW as it has some
* added niceties.
*
* DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
*/
#define ALLOC_GROW(x, nr, alloc) \
do { \
if ((nr) > alloc) { \
if (alloc_nr(alloc) < (nr)) \
alloc = (nr); \
else \
alloc = alloc_nr(alloc); \
REALLOC_ARRAY(x, alloc); \
} \
} while (0)
/*
* Similar to ALLOC_GROW but handles updating of the nr value and
* zeroing the bytes of the newly-grown array elements.
*
* DO NOT USE any expression with side-effect for any of the
* arguments.
*/
#define ALLOC_GROW_BY(x, nr, increase, alloc) \
do { \
if (increase) { \
size_t new_nr = nr + (increase); \
if (new_nr < nr) \
BUG("negative growth in ALLOC_GROW_BY"); \
ALLOC_GROW(x, new_nr, alloc); \
memset((x) + nr, 0, sizeof(*(x)) * (increase)); \
nr = new_nr; \
} \
} while (0)
static inline char *xstrdup_or_null(const char *str)
{
return str ? xstrdup(str) : NULL;
}
static inline size_t xsize_t(off_t len)
{
if (len < 0 || (uintmax_t) len > SIZE_MAX)
die("Cannot handle files this big");
return (size_t) len;
}
/*
* Like skip_prefix, but compare case-insensitively. Note that the comparison
* is done via tolower(), so it is strictly ASCII (no multi-byte characters or
* locale-specific conversions).
*/
static inline bool skip_iprefix(const char *str, const char *prefix,
const char **out)
{
do {
if (!*prefix) {
*out = str;
return true;
}
} while (tolower(*str++) == tolower(*prefix++));
return false;
}
/*
* Like skip_prefix_mem, but compare case-insensitively. Note that the
* comparison is done via tolower(), so it is strictly ASCII (no multi-byte
* characters or locale-specific conversions).
*/
static inline bool skip_iprefix_mem(const char *buf, size_t len,
const char *prefix,
const char **out, size_t *outlen)
{
do {
if (!*prefix) {
*out = buf;
*outlen = len;
return true;
}
} while (len-- > 0 && tolower(*buf++) == tolower(*prefix++));
return false;
}
static inline int strtoul_ui(char const *s, int base, unsigned int *result)
{
unsigned long ul;
char *p;
errno = 0;
/* negative values would be accepted by strtoul */
if (strchr(s, '-'))
return -1;
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;
}
#ifndef REG_STARTEND
#error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
#endif
static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
size_t nmatch, regmatch_t pmatch[], int eflags)
{
assert(nmatch > 0 && pmatch);
pmatch[0].rm_so = 0;
pmatch[0].rm_eo = size;
return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
}
#ifdef USE_ENHANCED_BASIC_REGULAR_EXPRESSIONS
int git_regcomp(regex_t *preg, const char *pattern, int cflags);
#define regcomp git_regcomp
#endif
#ifndef DIR_HAS_BSD_GROUP_SEMANTICS
# define FORCE_DIR_SET_GID S_ISGID
#else
# define FORCE_DIR_SET_GID 0
#endif
#ifdef UNRELIABLE_FSTAT
#define fstat_is_reliable() 0
#else
#define fstat_is_reliable() 1
#endif
/* usage.c: only to be used for testing BUG() implementation (see test-tool) */
extern int BUG_exit_code;
/* usage.c: if bug() is called we should have a BUG_if_bug() afterwards */
extern int bug_called_must_BUG;
__attribute__((format (printf, 3, 4))) NORETURN
void BUG_fl(const char *file, int line, const char *fmt, ...);
#define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
/* ASSERT: like assert(), but won't be compiled out with NDEBUG */
#define ASSERT(a) if (!(a)) BUG("Assertion `" #a "' failed.")
__attribute__((format (printf, 3, 4)))
void bug_fl(const char *file, int line, const char *fmt, ...);
#define bug(...) bug_fl(__FILE__, __LINE__, __VA_ARGS__)
#define BUG_if_bug(...) do { \
if (bug_called_must_BUG) \
BUG_fl(__FILE__, __LINE__, __VA_ARGS__); \
} while (0)
#ifndef FSYNC_METHOD_DEFAULT
#ifdef __APPLE__
#define FSYNC_METHOD_DEFAULT FSYNC_METHOD_WRITEOUT_ONLY
#else
#define FSYNC_METHOD_DEFAULT FSYNC_METHOD_FSYNC
#endif
#endif
#ifndef SHELL_PATH
# define SHELL_PATH "/bin/sh"
#endif
/*
* Our code often opens a path to an optional file, to work on its
* contents when we can successfully open it. We can ignore a failure
* to open if such an optional file does not exist, but we do want to
* report a failure in opening for other reasons (e.g. we got an I/O
* error, or the file is there, but we lack the permission to open).
*
* Call this function after seeing an error from open() or fopen() to
* see if the errno indicates a missing file that we can safely ignore.
*/
static inline int is_missing_file_error(int errno_)
{
return (errno_ == ENOENT || errno_ == ENOTDIR);
}
int cmd_main(int, const char **);
/*
* Intercept all calls to exit() and route them to trace2 to
* optionally emit a message before calling the real exit().
*/
int common_exit(const char *file, int line, int code);
#define exit(code) exit(common_exit(__FILE__, __LINE__, (code)))
/*
* This include must come after system headers, since it introduces macros that
* replace system names.
*/
#include "banned.h"
/*
* container_of - Get the address of an object containing a field.
*
* @ptr: pointer to the field.
* @type: type of the object.
* @member: name of the field within the object.
*/
#define container_of(ptr, type, member) \
((type *) ((char *)(ptr) - offsetof(type, member)))
/*
* helper function for `container_of_or_null' to avoid multiple
* evaluation of @ptr
*/
static inline void *container_of_or_null_offset(void *ptr, size_t offset)
{
return ptr ? (char *)ptr - offset : NULL;
}
/*
* like `container_of', but allows returned value to be NULL
*/
#define container_of_or_null(ptr, type, member) \
(type *)container_of_or_null_offset(ptr, offsetof(type, member))
/*
* like offsetof(), but takes a pointer to a variable of type which
* contains @member, instead of a specified type.
* @ptr is subject to multiple evaluation since we can't rely on __typeof__
* everywhere.
*/
#if defined(__GNUC__) /* clang sets this, too */
#define OFFSETOF_VAR(ptr, member) offsetof(__typeof__(*ptr), member)
#else /* !__GNUC__ */
#define OFFSETOF_VAR(ptr, member) \
((uintptr_t)&(ptr)->member - (uintptr_t)(ptr))
#endif /* !__GNUC__ */
/*
* Prevent an overly clever compiler from optimizing an expression
* out, triggering a false positive when building with the
* -Wunreachable-code option. false_but_the_compiler_does_not_know_it_
* is defined in a compilation unit separate from where the macro is
* used, initialized to 0, and never modified.
*/
#define NOT_CONSTANT(expr) ((expr) || false_but_the_compiler_does_not_know_it_)
extern int false_but_the_compiler_does_not_know_it_;
#ifdef CHECK_ASSERTION_SIDE_EFFECTS
#undef assert
extern int not_supposed_to_survive;
#define assert(expr) ((void)(not_supposed_to_survive || (expr)))
#endif /* CHECK_ASSERTION_SIDE_EFFECTS */
#endif
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