b7d8c0dbb

Denis Vlasenko

2009-04-10

FAILED Duration: 34s

Subject

hush: first stab at function support. argv passing is not coded yet. Only very rudimentary testing was done. With function support off, code growth is zero, with it on:

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/hush.c +169 -64

shell/hush.c+169 -64

@@ -86,7 +86,7 @@
	*/
	#define HUSH_DEBUG 1
	/* In progress... */
-	#define ENABLE_HUSH_FUNCTIONS 0
+	#define ENABLE_HUSH_FUNCTIONS 1


	#if BUILD_AS_NOMMU
@@ -374,12 +374,12 @@ struct command {
	#define GRP_NORMAL 0
	#define GRP_SUBSHELL 1
	#if ENABLE_HUSH_FUNCTIONS
-	#define GRP_FUNCTION 2
+	# define GRP_FUNCTION 2
	#endif

	struct pipe {
	struct pipe *next;
-	int num_cmds; /* total number of commands in job */
+	int num_cmds; /* total number of commands in pipe */
	int alive_cmds; /* number of commands running (not exited) */
	int stopped_cmds; /* number of commands alive, but stopped */
	#if ENABLE_HUSH_JOB
@@ -452,6 +452,12 @@ enum {
	BC_CONTINUE = 2,
	};

+	struct function {
+	struct function *next;
+	char *name;
+	struct pipe *body;
+	};
+

	/* "Globals" within this file */
	/* Sorted roughly by size (smaller offsets == smaller code) */
@@ -504,6 +510,7 @@ struct globals {
	const char *cwd;
	struct variable top_var; / = &G.shell_ver (set in main()) */
	struct variable shell_ver;
+	struct function *top_func;
	/* Signal and trap handling */
	// unsigned count_SIGCHLD;
	// unsigned handled_SIGCHLD;
@@ -2585,6 +2592,35 @@ static void free_pipe_list(struct pipe *head, int indent)
	}


+	static const struct built_in_command* find_builtin(const char *name)
+	{
+	const struct built_in_command *x;
+	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
+	if (strcmp(name, x->cmd) != 0)
+	continue;
+	debug_printf_exec("found builtin '%s'\n", name);
+	return x;
+	}
+	return NULL;
+	}
+
+	# if ENABLE_HUSH_FUNCTIONS
+	static const struct function find_function(const char name)
+	{
+	const struct function *funcp = G.top_func;
+	while (funcp) {
+	if (strcmp(name, funcp->name) != 0)
+	continue;
+	return funcp;
+	debug_printf_exec("found function '%s'\n", name);
+	}
+	return NULL;
+	}
+	#endif
+
+
+	static int run_list(struct pipe *pi);
+
	#if BB_MMU
	#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
	pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
@@ -2627,6 +2663,11 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save,
	#endif
	}

+	#if ENABLE_FEATURE_SH_STANDALONE \|\| BB_MMU
+	if (strchr(argv[0], '/') != NULL)
+	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
@@ -2640,30 +2681,38 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save,
	*/
	{
	int rcode;
-	const struct built_in_command *x;
-	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
-	if (strcmp(argv[0], x->cmd) == 0) {
-	debug_printf_exec("running builtin '%s'\n",
-	argv[0]);
-	rcode = x->function(argv);
-	fflush(NULL);
-	_exit(rcode);
-	}
+	const struct built_in_command *x = find_builtin(argv[0]);
+	if (x) {
+	rcode = x->function(argv);
+	fflush(NULL);
+	_exit(rcode);
	}
	}
+	# if ENABLE_HUSH_FUNCTIONS
+	/* Check if the command matches any functions */
+	{
+	int rcode;
+	const struct function *funcp = find_function(argv[0]);
+	if (funcp) {
+	rcode = run_list(funcp->body);
+	fflush(NULL);
+	_exit(rcode);
+	}
+	}
+	# endif
	#endif

	#if ENABLE_FEATURE_SH_STANDALONE
	/* Check if the command matches any busybox applets */
-	if (strchr(argv[0], '/') == NULL) {
+	{
	int a = find_applet_by_name(argv[0]);
	if (a >= 0) {
-	#if BB_MMU /* see above why on NOMMU it is not allowed */
+	# if BB_MMU /* see above why on NOMMU it is not allowed */
	if (APPLET_IS_NOEXEC(a)) {
	debug_printf_exec("running applet '%s'\n", argv[0]);
	run_applet_no_and_exit(a, argv);
	}
-	#endif
+	# endif
	/* Re-exec ourselves */
	debug_printf_exec("re-execing applet '%s'\n", argv[0]);
	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
@@ -2674,6 +2723,7 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save,
	}
	#endif

+	skip:
	debug_printf_exec("execing '%s'\n", argv[0]);
	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
	execvp(argv[0], argv);
@@ -2681,8 +2731,6 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save,
	_exit(EXIT_FAILURE);
	}

-	static int run_list(struct pipe *pi);
-
	/* Called after [v]fork() in run_pipe
	*/
	static void pseudo_exec(nommu_save_t *nommu_save,
@@ -3031,8 +3079,35 @@ static int run_pipe(struct pipe *pi)
	if (command->group) {
	#if ENABLE_HUSH_FUNCTIONS
	if (command->grp_type == GRP_FUNCTION) {
-	/* func () { list } */
-	bb_error_msg("here we ought to remember function definition, and go on");
+	/* "executing" func () { list } */
+	struct function *funcp;
+	struct function **funcpp = &G.top_func;
+
+	while ((funcp = *funcpp) != NULL) {
+	if (strcmp(funcp->name, command->argv[0]) == 0) {
+	debug_printf_exec("replacing function '%s'", funcp->name);
+	free(funcp->name);
+	free_pipe_list(funcp->body, /* indent: */ 0);
+	goto skip;
+	}
+	funcpp = &funcp->next;
+	}
+	debug_printf_exec("remembering new function '%s'", funcp->name);
+	funcp = funcpp = xzalloc(sizeof(funcp));
+	/funcp->next = NULL;/
+	skip:
+	funcp->name = command->argv[0];
+	funcp->body = command->group;
+	command->group = NULL;
+	command->argv[0] = NULL;
+	free_strings(command->argv);
+	command->argv = NULL;
+	/* note: if we are in a loop, future "executions"
+	* of func def will see it as null command since
+	* command->group == NULL and command->argv == NULL */
+	//this isn't exactly right: while...do f1() {a;}; f1; f1 {b;}; done
+	//second loop will execute b!
+
	return EXIT_SUCCESS;
	}
	#endif
@@ -3052,6 +3127,11 @@ static int run_pipe(struct pipe *pi)
	argv = command->argv ? command->argv : (char **) &null_ptr;
	{
	const struct built_in_command *x;
+	#if ENABLE_HUSH_FUNCTIONS
+	const struct function *funcp;
+	#else
+	enum { funcp = 0 };
+	#endif
	char **new_env = NULL;
	char **old_env = NULL;

@@ -3078,13 +3158,18 @@ static int run_pipe(struct pipe *pi)
	/* Expand the rest into (possibly) many strings each */
	argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);

-	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
-	if (strcmp(argv_expanded[0], x->cmd) != 0)
-	continue;
-	if (x->function == builtin_exec && argv_expanded[1] == NULL) {
-	debug_printf("exec with redirects only\n");
-	rcode = setup_redirects(command, NULL);
-	goto clean_up_and_ret1;
+	x = find_builtin(argv_expanded[0]);
+	#if ENABLE_HUSH_FUNCTIONS
+	if (!x)
+	funcp = find_function(argv_expanded[0]);
+	#endif
+	if (x \|\| funcp) {
+	if (!funcp) {
+	if (x->function == builtin_exec && argv_expanded[1] == NULL) {
+	debug_printf("exec with redirects only\n");
+	rcode = setup_redirects(command, NULL);
+	goto clean_up_and_ret1;
+	}
	}
	debug_printf("builtin inline %s\n", argv_expanded[0]);
	/* XXX setup_redirects acts on file descriptors, not FILEs.
@@ -3095,9 +3180,18 @@ static int run_pipe(struct pipe *pi)
	if (rcode == 0) {
	new_env = expand_assignments(argv, command->assignment_cnt);
	old_env = putenv_all_and_save_old(new_env);
-	debug_printf_exec(": builtin '%s' '%s'...\n",
+	if (!funcp) {
+	debug_printf_exec(": builtin '%s' '%s'...\n",
	x->cmd, argv_expanded[1]);
-	rcode = x->function(argv_expanded) & 0xff;
+	rcode = x->function(argv_expanded) & 0xff;
+	}
+	#if ENABLE_HUSH_FUNCTIONS
+	else {
+	debug_printf_exec(": function '%s' '%s'...\n",
+	funcp->name, argv_expanded[1]);
+	rcode = run_list(funcp->body) & 0xff;
+	}
+	#endif
	}
	#if ENABLE_FEATURE_SH_STANDALONE
	clean_up_and_ret:
@@ -3114,6 +3208,7 @@ static int run_pipe(struct pipe *pi)
	debug_printf_exec("run_pipe return %d\n", rcode);
	return rcode;
	}
+
	#if ENABLE_FEATURE_SH_STANDALONE
	i = find_applet_by_name(argv_expanded[0]);
	if (i >= 0 && APPLET_IS_NOFORK(i)) {
@@ -4081,6 +4176,10 @@ static int done_word(o_string word, struct parse_context ctx)
	}
	}
	command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
+	//SEGV, but good idea.
+	// command->argv = add_string_to_strings(command->argv, word->data);
+	// word->data = NULL;
+	// word->length = 0;
	debug_print_strings("word appended to argv", command->argv);
	}

@@ -4089,7 +4188,7 @@ static int done_word(o_string word, struct parse_context ctx)
	if (word->o_quoted
	\|\| !is_well_formed_var_name(command->argv[0], '\0')
	) {
-	/* bash says "not a valid identifier" */
+	/* bash says just "not a valid identifier" */
	syntax_error("not a valid identifier in for");
	return 1;
	}
@@ -4462,27 +4561,55 @@ static int parse_group(o_string dest, struct parse_context ctx,

	debug_printf_parse("parse_group entered\n");
	#if ENABLE_HUSH_FUNCTIONS
-	if (ch == 'F') { /* function definition? */
-	bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
-	//command->fname = dest->data;
-	command->grp_type = GRP_FUNCTION;
-	memset(dest, 0, sizeof(*dest));
+	if (ch == '(') {
+	if (!dest->o_quoted) {
+	if (dest->length)
+	done_word(dest, ctx);
+	if (!command->argv)
+	goto skip; /* (... */
+	if (command->argv[1]) { /* word word ... (... */
+	syntax_error("unexpected character (");
+	return 1;
+	}
+	/* it is "word(..." or "word (..." */
+	do
+	ch = i_getch(input);
+	while (ch == ' ' \|\| ch == '\t');
+	if (ch != ')') {
+	syntax_error("unexpected character X");
+	return 1;
+	}
+	do
+	ch = i_getch(input);
+	while (ch == ' ' \|\| ch == '\t' \|\| ch == '\n');
+	if (ch != '{') {
+	syntax_error("unexpected character X");
+	return 1;
+	}
+	command->grp_type = GRP_FUNCTION;
+	goto skip;
+	}
	}
	#endif
-	if (command->argv /* word [word](... */
-	\|\| dest->length /* word(... */
-	\|\| dest->o_quoted /* ""(... */
+	if (command->argv /* word [word]{... */
+	\|\| dest->length /* word{... */
+	\|\| dest->o_quoted /* ""{... */
	) {
	syntax_error(NULL);
	debug_printf_parse("parse_group return 1: "
	"syntax error, groups and arglists don't mix\n");
	return 1;
	}
+
+	#if ENABLE_HUSH_FUNCTIONS
+	skip:
+	#endif
	endch = '}';
	if (ch == '(') {
	endch = ')';
	command->grp_type = GRP_SUBSHELL;
	}
+
	{
	#if !BB_MMU
	char *as_string = NULL;
@@ -5310,28 +5437,6 @@ static struct pipe parse_stream(char *pstring,
	) {
	continue;
	}
-	#endif
-	#if ENABLE_HUSH_FUNCTIONS
-	if (dest.length != 0 /* not just () but word() */
-	&& dest.o_quoted == 0 /* not a"b"c() */
-	&& ctx.command->argv == NULL /* it's the first word */
-	//TODO: "func ( ) {...}" - note spaces - is valid format too in bash
-	&& i_peek(input) == ')'
-	&& !match_reserved_word(&dest)
-	) {
-	bb_error_msg("seems like a function definition");
-	i_getch(input);
-	//if !BB_MMU o_addchr(&ctx.as_string...
-	do {
-	//TODO: do it properly.
-	ch = i_getch(input);
-	} while (ch == ' ' \|\| ch == '\n');
-	if (ch != '{') {
-	syntax_error("was expecting {");
-	goto parse_error;
-	}
-	ch = 'F'; /* magic value */
-	}
	#endif
	case '{':
	if (parse_group(&dest, &ctx, input, ch) != 0) {
@@ -6427,11 +6532,11 @@ static int builtin_unset(char **argv)
	ret = EXIT_FAILURE;
	}
	}
-	#if ENABLE_HUSH_FUNCTIONS
-	else {
-	unset_local_func(*argv);
-	}
-	#endif
+	//#if ENABLE_HUSH_FUNCTIONS
+	// else {
+	// unset_local_func(*argv);
+	// }
+	//#endif
	argv++;
	}
	return ret;