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Diffstat (limited to 'git-compat-util.h')
| -rw-r--r-- | git-compat-util.h | 1105 |
1 files changed, 1105 insertions, 0 deletions
diff --git a/git-compat-util.h b/git-compat-util.h new file mode 100644 index 0000000000..9408f463e3 --- /dev/null +++ b/git-compat-util.h @@ -0,0 +1,1105 @@ +#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 |