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Diffstat (limited to 'src/system.h')
| -rw-r--r-- | src/system.h | 778 |
1 files changed, 778 insertions, 0 deletions
diff --git a/src/system.h b/src/system.h new file mode 100644 index 0000000..0c5c9b9 --- /dev/null +++ b/src/system.h @@ -0,0 +1,778 @@ +/* system-dependent definitions for coreutils + Copyright (C) 1989-2022 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Include this file _after_ system headers if possible. */ + +#include <attribute.h> + +#include <alloca.h> + +#include <sys/stat.h> + +/* Commonly used file permission combination. */ +#define MODE_RW_UGO (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH) + +#if HAVE_SYS_PARAM_H +# include <sys/param.h> +#endif + +#include <unistd.h> + +#include <limits.h> + +#include "pathmax.h" +#ifndef PATH_MAX +# define PATH_MAX 8192 +#endif + +#include "configmake.h" + +#include <sys/time.h> +#include <time.h> + +/* Since major is a function on SVR4, we can't use 'ifndef major'. */ +#if MAJOR_IN_MKDEV +# include <sys/mkdev.h> +# define HAVE_MAJOR +#endif +#if MAJOR_IN_SYSMACROS +# include <sys/sysmacros.h> +# define HAVE_MAJOR +#endif +#ifdef major /* Might be defined in sys/types.h. */ +# define HAVE_MAJOR +#endif + +#ifndef HAVE_MAJOR +# define major(dev) (((dev) >> 8) & 0xff) +# define minor(dev) ((dev) & 0xff) +# define makedev(maj, min) (((maj) << 8) | (min)) +#endif +#undef HAVE_MAJOR + +#if ! defined makedev && defined mkdev +# define makedev(maj, min) mkdev (maj, min) +#endif + +#include <string.h> +#include <errno.h> + +/* Some systems don't define this; POSIX mentions it but says it is + obsolete. gnulib defines it, but only on native Windows systems, + and there only because MSVC 10 does. */ +#ifndef ENODATA +# define ENODATA (-1) +#endif + +#include <stdbool.h> +#include <stdlib.h> +#include "version.h" + +/* Exit statuses for programs like 'env' that exec other programs. */ +enum +{ + EXIT_TIMEDOUT = 124, /* Time expired before child completed. */ + EXIT_CANCELED = 125, /* Internal error prior to exec attempt. */ + EXIT_CANNOT_INVOKE = 126, /* Program located, but not usable. */ + EXIT_ENOENT = 127 /* Could not find program to exec. */ +}; + +#include "exitfail.h" + +/* Set exit_failure to STATUS if that's not the default already. */ +static inline void +initialize_exit_failure (int status) +{ + if (status != EXIT_FAILURE) + exit_failure = status; +} + +#include <fcntl.h> +#ifdef O_PATH +enum { O_PATHSEARCH = O_PATH }; +#else +enum { O_PATHSEARCH = O_SEARCH }; +#endif + +#include <dirent.h> +#ifndef _D_EXACT_NAMLEN +# define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name) +#endif + +enum +{ + NOT_AN_INODE_NUMBER = 0 +}; + +#ifdef D_INO_IN_DIRENT +# define D_INO(dp) (dp)->d_ino +#else +/* Some systems don't have inodes, so fake them to avoid lots of ifdefs. */ +# define D_INO(dp) NOT_AN_INODE_NUMBER +#endif + +/* include here for SIZE_MAX. */ +#include <inttypes.h> + +/* Redirection and wildcarding when done by the utility itself. + Generally a noop, but used in particular for OS/2. */ +#ifndef initialize_main +# ifndef __OS2__ +# define initialize_main(ac, av) +# else +# define initialize_main(ac, av) \ + do { _wildcard (ac, av); _response (ac, av); } while (0) +# endif +#endif + +#include "stat-macros.h" + +#include "timespec.h" + +#include <ctype.h> + +/* ISDIGIT differs from isdigit, as follows: + - Its arg may be any int or unsigned int; it need not be an unsigned char + or EOF. + - It's typically faster. + POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to + isdigit unless it's important to use the locale's definition + of 'digit' even when the host does not conform to POSIX. */ +#define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9) + +/* Convert a possibly-signed character to an unsigned character. This is + a bit safer than casting to unsigned char, since it catches some type + errors that the cast doesn't. */ +static inline unsigned char to_uchar (char ch) { return ch; } + +/* '\n' is considered a field separator with --zero-terminated. */ +static inline bool +field_sep (unsigned char ch) +{ + return isblank (ch) || ch == '\n'; +} + +#include <locale.h> + +/* Take care of NLS matters. */ + +#include "gettext.h" +#if ! ENABLE_NLS +# undef textdomain +# define textdomain(Domainname) /* empty */ +# undef bindtextdomain +# define bindtextdomain(Domainname, Dirname) /* empty */ +#endif + +#define _(msgid) gettext (msgid) +#define N_(msgid) msgid + +/* Return a value that pluralizes the same way that N does, in all + languages we know of. */ +static inline unsigned long int +select_plural (uintmax_t n) +{ + /* Reduce by a power of ten, but keep it away from zero. The + gettext manual says 1000000 should be safe. */ + enum { PLURAL_REDUCER = 1000000 }; + return (n <= ULONG_MAX ? n : n % PLURAL_REDUCER + PLURAL_REDUCER); +} + +#define STREQ(a, b) (strcmp (a, b) == 0) +#define STREQ_LEN(a, b, n) (strncmp (a, b, n) == 0) +#define STRPREFIX(a, b) (strncmp (a, b, strlen (b)) == 0) + +/* Just like strncmp, but the second argument must be a literal string + and you don't specify the length; that comes from the literal. */ +#define STRNCMP_LIT(s, lit) strncmp (s, "" lit "", sizeof (lit) - 1) + +#if !HAVE_DECL_GETLOGIN +char *getlogin (void); +#endif + +#if !HAVE_DECL_TTYNAME +char *ttyname (int); +#endif + +#if !HAVE_DECL_GETEUID +uid_t geteuid (void); +#endif + +#if !HAVE_DECL_GETPWUID +struct passwd *getpwuid (uid_t); +#endif + +#if !HAVE_DECL_GETGRGID +struct group *getgrgid (gid_t); +#endif + +/* Interix has replacements for getgr{gid,nam,ent}, that don't + query the domain controller for group members when not required. + This speeds up the calls tremendously (<1 ms vs. >3 s). */ +/* To protect any system that could provide _nomembers functions + other than interix, check for HAVE_SETGROUPS, as interix is + one of the very few (the only?) platform that lacks it */ +#if ! HAVE_SETGROUPS +# if HAVE_GETGRGID_NOMEMBERS +# define getgrgid(gid) getgrgid_nomembers(gid) +# endif +# if HAVE_GETGRNAM_NOMEMBERS +# define getgrnam(nam) getgrnam_nomembers(nam) +# endif +# if HAVE_GETGRENT_NOMEMBERS +# define getgrent() getgrent_nomembers() +# endif +#endif + +#if !HAVE_DECL_GETUID +uid_t getuid (void); +#endif + +#include "xalloc.h" +#include "verify.h" + +/* This is simply a shorthand for the common case in which + the third argument to x2nrealloc would be 'sizeof *(P)'. + Ensure that sizeof *(P) is *not* 1. In that case, it'd be + better to use X2REALLOC, although not strictly necessary. */ +#define X2NREALLOC(P, PN) verify_expr (sizeof *(P) != 1, \ + x2nrealloc (P, PN, sizeof *(P))) + +/* Using x2realloc (when appropriate) usually makes your code more + readable than using x2nrealloc, but it also makes it so your + code will malfunction if sizeof *(P) ever becomes 2 or greater. + So use this macro instead of using x2realloc directly. */ +#define X2REALLOC(P, PN) verify_expr (sizeof *(P) == 1, \ + x2realloc (P, PN)) + +#include "unlocked-io.h" +#include "same-inode.h" + +#include "dirname.h" +#include "openat.h" + +static inline bool +dot_or_dotdot (char const *file_name) +{ + if (file_name[0] == '.') + { + char sep = file_name[(file_name[1] == '.') + 1]; + return (! sep || ISSLASH (sep)); + } + else + return false; +} + +/* A wrapper for readdir so that callers don't see entries for '.' or '..'. */ +static inline struct dirent const * +readdir_ignoring_dot_and_dotdot (DIR *dirp) +{ + while (true) + { + struct dirent const *dp = readdir (dirp); + if (dp == NULL || ! dot_or_dotdot (dp->d_name)) + return dp; + } +} + +/* Return true if DIR is determined to be an empty directory. + Return false with ERRNO==0 if DIR is a non empty directory. + Return false if not able to determine if directory empty. */ +static inline bool +is_empty_dir (int fd_cwd, char const *dir) +{ + DIR *dirp; + struct dirent const *dp; + int saved_errno; + int fd = openat (fd_cwd, dir, + (O_RDONLY | O_DIRECTORY + | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK)); + + if (fd < 0) + return false; + + dirp = fdopendir (fd); + if (dirp == NULL) + { + close (fd); + return false; + } + + errno = 0; + dp = readdir_ignoring_dot_and_dotdot (dirp); + saved_errno = errno; + closedir (dirp); + errno = saved_errno; + if (dp != NULL) + return false; + return saved_errno == 0 ? true : false; +} + +/* Factor out some of the common --help and --version processing code. */ + +/* These enum values cannot possibly conflict with the option values + ordinarily used by commands, including CHAR_MAX + 1, etc. Avoid + CHAR_MIN - 1, as it may equal -1, the getopt end-of-options value. */ +enum +{ + GETOPT_HELP_CHAR = (CHAR_MIN - 2), + GETOPT_VERSION_CHAR = (CHAR_MIN - 3) +}; + +#define GETOPT_HELP_OPTION_DECL \ + "help", no_argument, NULL, GETOPT_HELP_CHAR +#define GETOPT_VERSION_OPTION_DECL \ + "version", no_argument, NULL, GETOPT_VERSION_CHAR +#define GETOPT_SELINUX_CONTEXT_OPTION_DECL \ + "context", optional_argument, NULL, 'Z' + +#define case_GETOPT_HELP_CHAR \ + case GETOPT_HELP_CHAR: \ + usage (EXIT_SUCCESS); \ + break; + +/* Program_name must be a literal string. + Usually it is just PROGRAM_NAME. */ +#define USAGE_BUILTIN_WARNING \ + _("\n" \ +"NOTE: your shell may have its own version of %s, which usually supersedes\n" \ +"the version described here. Please refer to your shell's documentation\n" \ +"for details about the options it supports.\n") + +#define HELP_OPTION_DESCRIPTION \ + _(" --help display this help and exit\n") +#define VERSION_OPTION_DESCRIPTION \ + _(" --version output version information and exit\n") + +#include "closein.h" +#include "closeout.h" + +#define emit_bug_reporting_address unused__emit_bug_reporting_address +#include "version-etc.h" +#undef emit_bug_reporting_address + +#include "propername.h" +/* Define away proper_name (leaving proper_name_utf8, which affects far + fewer programs), since it's not worth the cost of adding ~17KB to + the x86_64 text size of every single program. This avoids a 40% + (almost ~2MB) increase in the file system space utilization for the set + of the 100 binaries. */ +#define proper_name(x) (x) + +#include "progname.h" + +#define case_GETOPT_VERSION_CHAR(Program_name, Authors) \ + case GETOPT_VERSION_CHAR: \ + version_etc (stdout, Program_name, PACKAGE_NAME, Version, Authors, \ + (char *) NULL); \ + exit (EXIT_SUCCESS); \ + break; + +#include "minmax.h" +#include "intprops.h" + +#ifndef SSIZE_MAX +# define SSIZE_MAX TYPE_MAXIMUM (ssize_t) +#endif + +#ifndef OFF_T_MIN +# define OFF_T_MIN TYPE_MINIMUM (off_t) +#endif + +#ifndef OFF_T_MAX +# define OFF_T_MAX TYPE_MAXIMUM (off_t) +#endif + +#ifndef UID_T_MAX +# define UID_T_MAX TYPE_MAXIMUM (uid_t) +#endif + +#ifndef GID_T_MAX +# define GID_T_MAX TYPE_MAXIMUM (gid_t) +#endif + +#ifndef PID_T_MAX +# define PID_T_MAX TYPE_MAXIMUM (pid_t) +#endif + +/* Use this to suppress gcc warnings. */ +#ifdef lint +# define IF_LINT(Code) Code +#else +# define IF_LINT(Code) /* empty */ +#endif + +/* main_exit should be called only from the main function. It is + equivalent to 'exit'. When checking for lint it calls 'exit', to + pacify gcc -fsanitize=lint which would otherwise have false alarms + for pointers in the main function's activation record. Otherwise + it simply returns from 'main'; this used to be what gcc's static + checking preferred and may yet be again. */ +#ifdef lint +# define main_exit(status) exit (status) +#else +# define main_exit(status) return status +#endif + +#ifdef __GNUC__ +# define LIKELY(cond) __builtin_expect ((cond), 1) +# define UNLIKELY(cond) __builtin_expect ((cond), 0) +#else +# define LIKELY(cond) (cond) +# define UNLIKELY(cond) (cond) +#endif + + +#if defined strdupa +# define ASSIGN_STRDUPA(DEST, S) \ + do { DEST = strdupa (S); } while (0) +#else +# define ASSIGN_STRDUPA(DEST, S) \ + do \ + { \ + char const *s_ = (S); \ + size_t len_ = strlen (s_) + 1; \ + char *tmp_dest_ = alloca (len_); \ + DEST = memcpy (tmp_dest_, s_, len_); \ + } \ + while (0) +#endif + +#if ! HAVE_SYNC +# define sync() /* empty */ +#endif + +/* Compute the greatest common divisor of U and V using Euclid's + algorithm. U and V must be nonzero. */ + +ATTRIBUTE_CONST +static inline size_t +gcd (size_t u, size_t v) +{ + do + { + size_t t = u % v; + u = v; + v = t; + } + while (v); + + return u; +} + +/* Compute the least common multiple of U and V. U and V must be + nonzero. There is no overflow checking, so callers should not + specify outlandish sizes. */ + +ATTRIBUTE_CONST +static inline size_t +lcm (size_t u, size_t v) +{ + return u * (v / gcd (u, v)); +} + +/* Return PTR, aligned upward to the next multiple of ALIGNMENT. + ALIGNMENT must be nonzero. The caller must arrange for ((char *) + PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable + locations. */ + +static inline void * +ptr_align (void const *ptr, size_t alignment) +{ + char const *p0 = ptr; + char const *p1 = p0 + alignment - 1; + return (void *) (p1 - (size_t) p1 % alignment); +} + +/* Return whether the buffer consists entirely of NULs. + Based on memeqzero in CCAN by Rusty Russell under CC0 (Public domain). */ + +ATTRIBUTE_PURE +static inline bool +is_nul (void const *buf, size_t length) +{ + const unsigned char *p = buf; +/* Using possibly unaligned access for the first 16 bytes + saves about 30-40 cycles, though it is strictly undefined behavior + and so would need __attribute__ ((__no_sanitize_undefined__)) + to avoid -fsanitize=undefined warnings. + Considering coreutils is mainly concerned with relatively + large buffers, we'll just use the defined behavior. */ +#if 0 && (_STRING_ARCH_unaligned || _STRING_INLINE_unaligned) + unsigned long word; +#else + unsigned char word; +#endif + + if (! length) + return true; + + /* Check len bytes not aligned on a word. */ + while (UNLIKELY (length & (sizeof word - 1))) + { + if (*p) + return false; + p++; + length--; + if (! length) + return true; + } + + /* Check up to 16 bytes a word at a time. */ + for (;;) + { + memcpy (&word, p, sizeof word); + if (word) + return false; + p += sizeof word; + length -= sizeof word; + if (! length) + return true; + if (UNLIKELY (length & 15) == 0) + break; + } + + /* Now we know first 16 bytes are NUL, memcmp with self. */ + return memcmp (buf, p, length) == 0; +} + +/* If 10*Accum + Digit_val is larger than the maximum value for Type, + then don't update Accum and return false to indicate it would + overflow. Otherwise, set Accum to that new value and return true. + Verify at compile-time that Type is Accum's type, and that Type is + unsigned. Accum must be an object, so that we can take its + address. Accum and Digit_val may be evaluated multiple times. + + The "Added check" below is not strictly required, but it causes GCC + to return a nonzero exit status instead of merely a warning + diagnostic, and that is more useful. */ + +#define DECIMAL_DIGIT_ACCUMULATE(Accum, Digit_val, Type) \ + ( \ + (void) (&(Accum) == (Type *) NULL), /* The type matches. */ \ + verify_expr (! TYPE_SIGNED (Type), /* The type is unsigned. */ \ + (((Type) -1 / 10 < (Accum) \ + || (Type) ((Accum) * 10 + (Digit_val)) < (Accum)) \ + ? false \ + : (((Accum) = (Accum) * 10 + (Digit_val)), true))) \ + ) + +static inline void +emit_stdin_note (void) +{ + fputs (_("\n\ +With no FILE, or when FILE is -, read standard input.\n\ +"), stdout); +} +static inline void +emit_mandatory_arg_note (void) +{ + fputs (_("\n\ +Mandatory arguments to long options are mandatory for short options too.\n\ +"), stdout); +} + +static inline void +emit_size_note (void) +{ + fputs (_("\n\ +The SIZE argument is an integer and optional unit (example: 10K is 10*1024).\n\ +Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000).\n\ +Binary prefixes can be used, too: KiB=K, MiB=M, and so on.\n\ +"), stdout); +} + +static inline void +emit_blocksize_note (char const *program) +{ + printf (_("\n\ +Display values are in units of the first available SIZE from --block-size,\n\ +and the %s_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.\n\ +Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).\n\ +"), program); +} + +static inline void +emit_backup_suffix_note (void) +{ + fputs (_("\ +\n\ +The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.\n\ +The version control method may be selected via the --backup option or through\n\ +the VERSION_CONTROL environment variable. Here are the values:\n\ +\n\ +"), stdout); + fputs (_("\ + none, off never make backups (even if --backup is given)\n\ + numbered, t make numbered backups\n\ + existing, nil numbered if numbered backups exist, simple otherwise\n\ + simple, never always make simple backups\n\ +"), stdout); +} + +static inline void +emit_ancillary_info (char const *program) +{ + struct infomap { char const *program; char const *node; } const infomap[] = { + { "[", "test invocation" }, + { "coreutils", "Multi-call invocation" }, + { "sha224sum", "sha2 utilities" }, + { "sha256sum", "sha2 utilities" }, + { "sha384sum", "sha2 utilities" }, + { "sha512sum", "sha2 utilities" }, + { NULL, NULL } + }; + + char const *node = program; + struct infomap const *map_prog = infomap; + + while (map_prog->program && ! STREQ (program, map_prog->program)) + map_prog++; + + if (map_prog->node) + node = map_prog->node; + + printf (_("\n%s online help: <%s>\n"), PACKAGE_NAME, PACKAGE_URL); + + /* Don't output this redundant message for English locales. + Note we still output for 'C' so that it gets included in the man page. */ + char const *lc_messages = setlocale (LC_MESSAGES, NULL); + if (lc_messages && STRNCMP_LIT (lc_messages, "en_")) + { + /* TRANSLATORS: Replace LANG_CODE in this URL with your language code + <https://translationproject.org/team/LANG_CODE.html> to form one of + the URLs at https://translationproject.org/team/. Otherwise, replace + the entire URL with your translation team's email address. */ + fputs (_("Report any translation bugs to " + "<https://translationproject.org/team/>\n"), stdout); + } + /* .htaccess on the coreutils web site maps programs to the appropriate page, + however we explicitly handle "[" -> "test" here as the "[" is not + recognized as part of a URL by default in terminals. */ + char const *url_program = STREQ (program, "[") ? "test" : program; + printf (_("Full documentation <%s%s>\n"), + PACKAGE_URL, url_program); + printf (_("or available locally via: info '(coreutils) %s%s'\n"), + node, node == program ? " invocation" : ""); +} + +/* Use a macro rather than an inline function, as this references + the global program_name, which causes dynamic linking issues + in libstdbuf.so on some systems where unused functions + are not removed by the linker. */ +#define emit_try_help() \ + do \ + { \ + fprintf (stderr, _("Try '%s --help' for more information.\n"), \ + program_name); \ + } \ + while (0) + +#include "inttostr.h" + +static inline char * +timetostr (time_t t, char *buf) +{ + return (TYPE_SIGNED (time_t) + ? imaxtostr (t, buf) + : umaxtostr (t, buf)); +} + +static inline char * +bad_cast (char const *s) +{ + return (char *) s; +} + +/* Return a boolean indicating whether SB->st_size is defined. */ +static inline bool +usable_st_size (struct stat const *sb) +{ + return (S_ISREG (sb->st_mode) || S_ISLNK (sb->st_mode) + || S_TYPEISSHM (sb) || S_TYPEISTMO (sb)); +} + +_Noreturn void usage (int status); + +/* Like error(0, 0, ...), but without an implicit newline. + Also a noop unless the global DEV_DEBUG is set. */ +#define devmsg(...) \ + do \ + { \ + if (dev_debug) \ + fprintf (stderr, __VA_ARGS__); \ + } \ + while (0) + +#define emit_cycle_warning(file_name) \ + do \ + { \ + error (0, 0, _("\ +WARNING: Circular directory structure.\n\ +This almost certainly means that you have a corrupted file system.\n\ +NOTIFY YOUR SYSTEM MANAGER.\n\ +The following directory is part of the cycle:\n %s\n"), \ + quotef (file_name)); \ + } \ + while (0) + +/* Like stpncpy, but do ensure that the result is NUL-terminated, + and do not NUL-pad out to LEN. I.e., when strnlen (src, len) == len, + this function writes a NUL byte into dest[len]. Thus, the length + of the destination buffer must be at least LEN + 1. + The DEST and SRC buffers must not overlap. */ +static inline char * +stzncpy (char *restrict dest, char const *restrict src, size_t len) +{ + char const *src_end = src + len; + while (src < src_end && *src) + *dest++ = *src++; + *dest = 0; + return dest; +} + +#ifndef ARRAY_CARDINALITY +# define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array)) +#endif + +/* Return true if ERR is ENOTSUP or EOPNOTSUPP, otherwise false. + This wrapper function avoids the redundant 'or'd comparison on + systems like Linux for which they have the same value. It also + avoids the gcc warning to that effect. */ +static inline bool +is_ENOTSUP (int err) +{ + return err == EOPNOTSUPP || (ENOTSUP != EOPNOTSUPP && err == ENOTSUP); +} + + +/* How coreutils quotes filenames, to minimize use of outer quotes, + but also provide better support for copy and paste when used. */ +#include "quotearg.h" + +/* Use these to shell quote only when necessary, + when the quoted item is already delimited with colons. */ +#define quotef(arg) \ + quotearg_n_style_colon (0, shell_escape_quoting_style, arg) +#define quotef_n(n, arg) \ + quotearg_n_style_colon (n, shell_escape_quoting_style, arg) + +/* Use these when there are spaces around the file name, + in the error message. */ +#define quoteaf(arg) \ + quotearg_style (shell_escape_always_quoting_style, arg) +#define quoteaf_n(n, arg) \ + quotearg_n_style (n, shell_escape_always_quoting_style, arg) |