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d6b05eb9c

Denys Vlasenko

2009-06-06

FAILED Duration: 28s

Subject

hush: make builtins work in pipes (eval ... | ...) on NOMMU

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

shell/ash.c +1 -1 shell/hush.c +183 -91 shell/lash_unused.c +1 -1 shell/msh.c +1 -1

shell/ash.c+1 -1

@@ -12233,7 +12233,7 @@ helpcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
	unsigned col;
	unsigned i;

-	out1fmt("\n"
+	out1fmt(
	"Built-in commands:\n"
	"------------------\n");
	for (col = 0, i = 0; i < ARRAY_SIZE(builtintab); i++) {

shell/hush.c+183 -91

@@ -50,7 +50,7 @@
	*
	* TODOs:
	* grep for "TODO" and fix (some of them are easy)
-	* builtins: ulimit, local
+	* builtins: ulimit
	* follow IFS rules more precisely, including update semantics
	* export builtin should be special, its arguments are assignments
	* and therefore expansion of them should be "one-word" expansion:
@@ -593,56 +593,58 @@ struct built_in_command {
	#endif
	};

-	/* For now, echo and test are unconditionally enabled.
-	* Maybe make it configurable? */
-	static const struct built_in_command bltins[] = {
-	BLTIN("." , builtin_source , "Run commands in a file"),
-	BLTIN(":" , builtin_true , "No-op"),
-	BLTIN("[" , builtin_test , "Test condition"),
+	static const struct built_in_command bltins1[] = {
+	BLTIN("." , builtin_source , "Run commands in a file"),
+	BLTIN(":" , builtin_true , NULL),
	#if ENABLE_HUSH_JOB
-	BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
+	BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
	#endif
	#if ENABLE_HUSH_LOOPS
-	BLTIN("break" , builtin_break , "Exit from a loop"),
+	BLTIN("break" , builtin_break , "Exit from a loop"),
	#endif
-	BLTIN("cd" , builtin_cd , "Change directory"),
+	BLTIN("cd" , builtin_cd , "Change directory"),
	#if ENABLE_HUSH_LOOPS
-	BLTIN("continue", builtin_continue, "Start new loop iteration"),
+	BLTIN("continue" , builtin_continue, "Start new loop iteration"),
	#endif
-	BLTIN("echo" , builtin_echo , "Write to stdout"),
-	BLTIN("eval" , builtin_eval , "Construct and run shell command"),
-	BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
-	BLTIN("exit" , builtin_exit , "Exit"),
-	BLTIN("export" , builtin_export , "Set environment variable"),
+	BLTIN("eval" , builtin_eval , "Construct and run shell command"),
+	BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
+	BLTIN("exit" , builtin_exit , "Exit"),
+	BLTIN("export" , builtin_export , "Set environment variables"),
	#if ENABLE_HUSH_JOB
-	BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
+	BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
	#endif
	#if ENABLE_HUSH_HELP
-	BLTIN("help" , builtin_help , "List shell built-in commands"),
+	BLTIN("help" , builtin_help , NULL),
	#endif
	#if ENABLE_HUSH_JOB
-	BLTIN("jobs" , builtin_jobs , "List active jobs"),
+	BLTIN("jobs" , builtin_jobs , "List jobs"),
	#endif
	#if ENABLE_HUSH_LOCAL
-	BLTIN("local" , builtin_local , "Set local variable"),
+	BLTIN("local" , builtin_local , "Set local variables"),
	#endif
	#if HUSH_DEBUG
-	BLTIN("memleak" , builtin_memleak , "Debug tool"),
+	BLTIN("memleak" , builtin_memleak , NULL),
	#endif
-	BLTIN("pwd" , builtin_pwd , "Print current directory"),
-	BLTIN("read" , builtin_read , "Input environment variable"),
+	BLTIN("read" , builtin_read , "Input into variable"),
	#if ENABLE_HUSH_FUNCTIONS
-	BLTIN("return" , builtin_return , "Return from a function"),
-	#endif
-	BLTIN("set" , builtin_set , "Set/unset shell local variables"),
-	BLTIN("shift" , builtin_shift , "Shift positional parameters"),
-	BLTIN("test" , builtin_test , "Test condition"),
-	BLTIN("trap" , builtin_trap , "Trap signals"),
-	BLTIN("type" , builtin_type , "Write a description of command type"),
-	// BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
-	BLTIN("umask" , builtin_umask , "Set file creation mask"),
-	BLTIN("unset" , builtin_unset , "Unset environment variable"),
-	BLTIN("wait" , builtin_wait , "Wait for process"),
+	BLTIN("return" , builtin_return , "Return from a function"),
+	#endif
+	BLTIN("set" , builtin_set , "Set/unset positional parameters"),
+	BLTIN("shift" , builtin_shift , "Shift positional parameters"),
+	BLTIN("trap" , builtin_trap , "Trap signals"),
+	BLTIN("type" , builtin_type , "Write a description of command type"),
+	// BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
+	BLTIN("umask" , builtin_umask , "Set file creation mask"),
+	BLTIN("unset" , builtin_unset , "Unset variables"),
+	BLTIN("wait" , builtin_wait , "Wait for process"),
+	};
+	/* For now, echo and test are unconditionally enabled.
+	* Maybe make it configurable? */
+	static const struct built_in_command bltins2[] = {
+	BLTIN("[" , builtin_test , NULL),
+	BLTIN("echo" , builtin_echo , NULL),
+	BLTIN("pwd" , builtin_pwd , NULL),
+	BLTIN("test" , builtin_test , NULL),
	};


@@ -1231,15 +1233,17 @@ static int check_and_run_traps(int sig)
	}


-	static const char *set_cwd(void)
+	static const char *get_cwd(int force)
	{
-	/* xrealloc_getcwd_or_warn(arg) calls free(arg),
-	* we must not try to free(bb_msg_unknown) */
-	if (G.cwd == bb_msg_unknown)
-	G.cwd = NULL;
-	G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
-	if (!G.cwd)
-	G.cwd = bb_msg_unknown;
+	if (force \|\| G.cwd == NULL) {
+	/* xrealloc_getcwd_or_warn(arg) calls free(arg),
+	* we must not try to free(bb_msg_unknown) */
+	if (G.cwd == bb_msg_unknown)
+	G.cwd = NULL;
+	G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
+	if (!G.cwd)
+	G.cwd = bb_msg_unknown;
+	}
	return G.cwd;
	}

@@ -1579,7 +1583,7 @@ static const char* setup_prompt_string(int promptmode)
	/* Set up the prompt */
	if (promptmode == 0) { /* PS1 */
	free((char*)G.PS1);
-	G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
+	G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
	prompt_str = G.PS1;
	} else
	prompt_str = G.PS2;
@@ -2511,7 +2515,9 @@ static char expand_assignments(char argv, int count)

	#if BB_MMU
	/* never called */
-	void re_execute_shell(char **to_free, const char s, char argv0, char *argv);
+	void re_execute_shell(char **to_free, const char s,
+	char g_argv0, char *g_argv,
+	char **builtin_argv) NORETURN;

	static void reset_traps_to_defaults(void)
	{
@@ -2563,10 +2569,14 @@ static void reset_traps_to_defaults(void)

	#else /* !BB_MMU */

-	static void re_execute_shell(char **to_free, const char s, char g_argv0, char *g_argv) NORETURN;
-	static void re_execute_shell(char **to_free, const char s, char g_argv0, char *g_argv)
+	static void re_execute_shell(char **to_free, const char s,
+	char g_argv0, char *g_argv,
+	char **builtin_argv) NORETURN;
+	static void re_execute_shell(char **to_free, const char s,
+	char g_argv0, char *g_argv,
+	char **builtin_argv)
	{
-	char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
+	char param_buf[sizeof("-$%x:%x:%x:%x:%x") + sizeof(unsigned) * 2];
	char *heredoc_argv[4];
	struct variable *cur;
	#if ENABLE_HUSH_FUNCTIONS
@@ -2585,16 +2595,22 @@ static void re_execute_shell(char **to_free, const char s, char *g_argv0, char
	goto do_exec;
	}

-	sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
+	cnt = 0;
+	pp = builtin_argv;
+	if (pp) while (*pp++)
+	cnt++;
+
+	sprintf(param_buf, "-$%x:%x:%x:%x" IF_HUSH_LOOPS(":%x")
	, (unsigned) G.root_pid
	, (unsigned) G.last_bg_pid
	, (unsigned) G.last_exitcode
+	, cnt
	IF_HUSH_LOOPS(, G.depth_of_loop)
	);
	/* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
	* 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
	*/
-	cnt = 6;
+	cnt += 6;
	for (cur = G.top_var; cur; cur = cur->next) {
	if (!cur->flg_export \|\| cur->flg_read_only)
	cnt += 2;
@@ -2648,6 +2664,11 @@ static void re_execute_shell(char **to_free, const char s, char *g_argv0, char
	*/
	pp++ = (char ) "-c";
	pp++ = (char ) s;
+	if (builtin_argv) {
+	while (*++builtin_argv)
+	pp++ = builtin_argv;
+	pp++ = (char ) "";
+	}
	*pp++ = g_argv0;
	while (*g_argv)
	pp++ = g_argv++;
@@ -2735,7 +2756,7 @@ static void setup_heredoc(struct redir_struct *redir)
	#else
	/* Delegate blocking writes to another process */
	xmove_fd(pair.wr, STDOUT_FILENO);
-	re_execute_shell(&to_free, heredoc, NULL, NULL);
+	re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
	#endif
	}
	/* parent */
@@ -2958,17 +2979,31 @@ static char find_in_path(const char arg)
	return ret;
	}

-	static const struct built_in_command* find_builtin(const char *name)
+	static const struct built_in_command* find_builtin_helper(const char *name,
+	const struct built_in_command *x,
+	const struct built_in_command *end)
	{
-	const struct built_in_command *x;
-	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
-	if (strcmp(name, x->cmd) != 0)
+	while (x != end) {
+	if (strcmp(name, x->cmd) != 0) {
+	x++;
	continue;
+	}
	debug_printf_exec("found builtin '%s'\n", name);
	return x;
	}
	return NULL;
	}
+	static const struct built_in_command* find_builtin1(const char *name)
+	{
+	return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
+	}
+	static const struct built_in_command* find_builtin(const char *name)
+	{
+	const struct built_in_command *x = find_builtin1(name);
+	if (x)
+	return x;
+	return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
+	}

	#if ENABLE_HUSH_FUNCTIONS
	static const struct function find_function(const char name)
@@ -3084,7 +3119,8 @@ static void exec_function(nommu_save_t *nommu_save,
	re_execute_shell(&nommu_save->argv_from_re_execing,
	funcp->body_as_string,
	G.global_argv[0],
-	argv + 1);
+	argv + 1,
+	NULL);
	# endif
	}

@@ -3148,6 +3184,37 @@ static int run_function(const struct function funcp, char *argv)
	#endif /* ENABLE_HUSH_FUNCTIONS */


+	# if BB_MMU
+	#define exec_builtin(nommu_save, x, argv) \
+	exec_builtin(x, argv)
+	# else
+	#define exec_builtin(nommu_save, x, argv) \
+	exec_builtin(nommu_save, argv)
+	# endif
+	static void exec_builtin(nommu_save_t *nommu_save,
+	const struct built_in_command *x,
+	char **argv) NORETURN;
+	static void exec_builtin(nommu_save_t *nommu_save,
+	const struct built_in_command *x,
+	char **argv)
+	{
+	# if BB_MMU
+	int rcode = x->function(argv);
+	fflush(NULL);
+	_exit(rcode);
+	# else
+	/* On NOMMU, we must never block!
+	* Example: { sleep 99 \| read line; } & echo Ok
+	*/
+	re_execute_shell(&nommu_save->argv_from_re_execing,
+	argv[0],
+	G.global_argv[0],
+	G.global_argv + 1,
+	argv);
+	# endif
+	}
+
+
	#if BB_MMU
	#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
	pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
@@ -3197,27 +3264,22 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save,
	goto skip;
	#endif

-	/* On NOMMU, we must never block!
-	* Example: { sleep 99999 \| read line } & echo Ok
-	* read builtin will block on read syscall, leaving parent blocked
-	* in vfork. Therefore we can't do this:
-	*/
-	#if BB_MMU
	/* Check if the command matches any of the builtins.
	* Depending on context, this might be redundant. But it's
	* easier to waste a few CPU cycles than it is to figure out
	* if this is one of those cases.
	*/
	{
-	int rcode;
-	const struct built_in_command *x = find_builtin(argv[0]);
+	/* On NOMMU, it is more expensive to re-execute shell
+	* just in order to run echo or test builtin.
+	* It's better to skip it here and run corresponding
+	* non-builtin later. */
+	const struct built_in_command *x;
+	x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
	if (x) {
-	rcode = x->function(argv);
-	fflush(NULL);
-	_exit(rcode);
+	exec_builtin(nommu_save, x, argv);
	}
	}
-	#endif
	#if ENABLE_HUSH_FUNCTIONS
	/* Check if the command matches any functions */
	{
@@ -3292,7 +3354,8 @@ static void pseudo_exec(nommu_save_t *nommu_save,
	re_execute_shell(&nommu_save->argv_from_re_execing,
	command->group_as_string,
	G.global_argv[0],
-	G.global_argv + 1);
+	G.global_argv + 1,
+	NULL);
	#endif
	}

@@ -5030,7 +5093,8 @@ static FILE generate_stream_from_string(const char s)
	re_execute_shell(&to_free,
	s,
	G.global_argv[0],
-	G.global_argv + 1);
+	G.global_argv + 1,
+	NULL);
	#endif
	}

@@ -6240,6 +6304,7 @@ int hush_main(int argc, char **argv)
	};
	int signal_mask_is_inited = 0;
	int opt;
+	unsigned builtin_argc;
	char **e;
	struct variable *cur_var;

@@ -6277,7 +6342,6 @@ int hush_main(int argc, char **argv)
	G.global_argc = argc;
	G.global_argv = argv;
	/* Initialize some more globals to non-zero values */
-	set_cwd();
	cmdedit_update_prompt();

	if (setjmp(die_jmp)) {
@@ -6297,6 +6361,7 @@ int hush_main(int argc, char **argv)

	/* Parse options */
	/* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
+	builtin_argc = 0;
	while (1) {
	opt = getopt(argc, argv, "c:xins"
	#if !BB_MMU
@@ -6310,15 +6375,40 @@ int hush_main(int argc, char **argv)
	break;
	switch (opt) {
	case 'c':
+	/* Possibilities:
+	* sh ... -c 'script'
+	* sh ... -c 'script' ARG0 [ARG1...]
+	* On NOMMU, if builtin_argc != 0,
+	* sh ... -c 'builtin' [BARGV...] "" ARG0 [ARG1...]
+	* "" needs to be replaced with NULL
+	* and BARGV vector fed to builtin function.
+	* Note: this form never happens:
+	* sh ... -c 'builtin' [BARGV...] ""
+	*/
	if (!G.root_pid)
	G.root_pid = getpid();
	G.global_argv = argv + optind;
-	if (!argv[optind]) {
-	/* -c 'script' (no params): prevent empty $0 */
-	*--G.global_argv = argv[0];
-	optind--;
-	} /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
	G.global_argc = argc - optind;
+	if (builtin_argc) {
+	/* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
+	const struct built_in_command *x;
+
+	block_signals(0); /* 0: called 1st time */
+	x = find_builtin(optarg);
+	if (x) { /* paranoia */
+	G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
+	G.global_argv += builtin_argc;
+	G.global_argv[-1] = NULL; /* replace "" */
+	G.last_exitcode = x->function(argv + optind - 1);
+	}
+	goto final_return;
+	}
+	if (!G.global_argv[0]) {
+	/* -c 'script' (no params): prevent empty $0 */
+	G.global_argv--; /* points to argv[i] of 'script' */
+	G.global_argv[0] = argv[0];
+	G.global_argc--;
+	} /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
	block_signals(0); /* 0: called 1st time */
	parse_and_run_string(optarg);
	goto final_return;
@@ -6341,6 +6431,8 @@ int hush_main(int argc, char **argv)
	G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
	optarg++;
	G.last_exitcode = bb_strtou(optarg, &optarg, 16);
+	optarg++;
+	builtin_argc = bb_strtou(optarg, &optarg, 16);
	# if ENABLE_HUSH_LOOPS
	optarg++;
	G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
@@ -6617,7 +6709,7 @@ static int FAST_FUNC builtin_cd(char **argv)
	bb_perror_msg("cd: %s", newdir);
	return EXIT_FAILURE;
	}
-	set_cwd();
+	get_cwd(1);
	return EXIT_SUCCESS;
	}

@@ -6663,17 +6755,16 @@ static int FAST_FUNC builtin_exit(char **argv)

	static void print_escaped(const char *s)
	{
+	if (*s == '\'')
+	goto squote;
	do {
-	if (*s != '\'') {
-	const char *p;
-
-	p = strchrnul(s, '\'');
-	/* print 'xxxx', possibly just '' */
-	printf("'%.*s'", (int)(p - s), s);
-	if (*p == '\0')
-	break;
-	s = p;
-	}
+	const char *p = strchrnul(s, '\'');
+	/* print 'xxxx', possibly just '' */
+	printf("'%.*s'", (int)(p - s), s);
+	if (*p == '\0')
+	break;
+	s = p;
+	squote:
	/* s points to '; print "'''...'''" */
	putchar('"');
	do putchar('\''); while (*++s == '\'');
@@ -6980,13 +7071,14 @@ static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
	{
	const struct built_in_command *x;

-	printf("\n"
+	printf(
	"Built-in commands:\n"
	"------------------\n");
-	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
-	printf("%s\t%s\n", x->cmd, x->descr);
+	for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
+	if (x->descr)
+	printf("%s\t%s\n", x->cmd, x->descr);
	}
-	printf("\n\n");
+	bb_putchar('\n');
	return EXIT_SUCCESS;
	}
	#endif
@@ -7041,7 +7133,7 @@ static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)

	static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
	{
-	puts(set_cwd());
+	puts(get_cwd(0));
	return EXIT_SUCCESS;
	}

shell/lash_unused.c+1 -1

@@ -312,7 +312,7 @@ static int builtin_help(struct child_prog UNUSED_PARAM *dummy)
	{
	const struct built_in_command *x;

-	printf("\n"
+	printf(
	"Built-in commands:\n"
	"------------------\n");
	for (x = bltins; x <= &VEC_LAST(bltins); x++) {

shell/msh.c+1 -1

@@ -3174,7 +3174,7 @@ static int dohelp(struct op t UNUSED_PARAM, char *args UNUSED_PARAM)
	int col;
	const struct builtincmd *x;

-	printf("\n"
+	printf(
	"Built-in commands:\n"
	"------------------\n");