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9d617c44d

Denys Vlasenko

2009-06-09

FAILED Duration: 34s

Subject

hush: specially handle [[ - suppress globbing & multiword expansion

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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

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Commit Diff GitHub →

shell/hush.c +112 -20 shell/hush_test/hush-bugs/export_exp.right +7 -0 shell/hush_test/hush-bugs/export_exp.tests +19 -0

shell/hush.c+112 -20

@@ -296,12 +296,40 @@ struct command {
	pid_t pid; /* 0 if exited */
	int assignment_cnt; /* how many argv[i] are assignments? */
	smallint is_stopped; /* is the command currently running? */
-	smallint grp_type; /* GRP_xxx */
-	#define GRP_NORMAL 0
-	#define GRP_SUBSHELL 1
+	smallint cmd_type; /* CMD_xxx */
+	#define CMD_NORMAL 0
+	#define CMD_SUBSHELL 1
+	/* used for "[[ EXPR ]]" */
+	#define CMD_SINGLEWORD_NOGLOB 2
+	/* used for "export noglob=* glob* a=`echo a b`" */
+	/* #define CMD_SINGLEWORD_NOGLOB_COND 3 */
+	// It is hard to implement correctly, adds significant amounts of tricky code,
+	// and all this only useful for really obscure export statements
+	// almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
+	// guard the code which implement it, but I have doubts it works
+	// in all cases (especially with mixed globbed/non-globbed arguments)
	#if ENABLE_HUSH_FUNCTIONS
-	# define GRP_FUNCTION 2
-	#endif
+	# define CMD_FUNCDEF 4
+	#endif
+	//TODO
+	//#define CMD_ARITH - let EXPR, ((EXPR))
+	//let EXPR [EXPR...]
+	// Each EXPR is an arithmetic expression to be evaluated (ARITHMETIC EVALUATION)
+	// If the last arg evaluates to 0, let returns 1; 0 is returned otherwise.
+	// NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
+	//((EXPR))
+	// The EXPR is evaluated according to ARITHMETIC EVALUATION.
+	// This is exactly equivalent to let "expression".
+	//[[ EXPR ]]
+	// Basically, word splitting and pathname expansion should NOT be performed
+	// Examples:
+	// no word splitting: a="a b"; [[ $a = "a b" ]]; echo $? should print "0"
+	// no pathname expansion: [[ /bin/m* = "/bin/m*" ]]; echo $? should print "0"
+	// Additional operators:
+	// \|\| and && should work as -o and -a
+	// =~ regexp match
+	// Apart from the above, [[ expr ]] should work as [ expr ]
+
	/* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
	struct pipe *group;
	#if !BB_MMU
@@ -310,11 +338,11 @@ struct command {
	#if ENABLE_HUSH_FUNCTIONS
	struct function *child_func;
	/* This field is used to prevent a bug here:
-	* while...do f1() {a;}; f1; f1 {b;}; f1; done
+	* while...do f1() {a;}; f1; f1() {b;}; f1; done
	* When we execute "f1() {a;}" cmd, we create new function and clear
	* cmd->group, cmd->group_as_string, cmd->argv[0].
-	* when we execute "f1 {b;}", we notice that f1 exists,
-	* and that it's "parent cmd" struct is still "alive",
+	* When we execute "f1() {b;}", we notice that f1 exists,
+	* and that its "parent cmd" struct is still "alive",
	* we put those fields back into cmd->xxx
	* (struct function has ->parent_cmd ptr to facilitate that).
	* When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
@@ -2440,7 +2468,7 @@ static char expand_variables(char argv, int or_mask)
	n = 0;
	v = argv;
	while (*v) {
-	n = expand_vars_to_list(&output, n, *v, (char)or_mask);
+	n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
	v++;
	}
	debug_print_list("expand_variables", &output, n);
@@ -2456,6 +2484,46 @@ static char expand_strvec_to_strvec(char argv)
	return expand_variables(argv, 0x100);
	}

+	static char expand_strvec_to_strvec_singleword_noglob(char argv)
+	{
+	return expand_variables(argv, 0x80);
+	}
+
+	#ifdef CMD_SINGLEWORD_NOGLOB_COND
+	static char expand_strvec_to_strvec_singleword_noglob_cond(char argv)
+	{
+	int n;
+	char **list;
+	char **v;
+	o_string output = NULL_O_STRING;
+
+	n = 0;
+	v = argv;
+	while (*v) {
+	int is_var = is_well_formed_var_name(*v, '=');
+	/* is_var * 0x80: singleword expansion for vars */
+	n = expand_vars_to_list(&output, n, v, is_var 0x80);
+
+	/* Subtle! expand_vars_to_list did not glob last word yet.
+	* It does this only when fed with further data.
+	* Therefore we set globbing flags AFTER it, not before:
+	*/
+
+	/* if it is not recognizably abc=...; then: */
+	output.o_escape = !is_var; /* protect against globbing for "$var" */
+	/* (unquoted $var will temporarily switch it off) */
+	output.o_glob = !is_var; /* and indeed do globbing */
+	v++;
+	}
+	debug_print_list("expand_cond", &output, n);
+
+	/* output.data (malloced in one block) gets returned in "list" */
+	list = o_finalize_list(&output, n);
+	debug_print_strings("expand_cond[1]", list);
+	return list;
+	}
+	#endif
+
	/* Used for expansion of right hand of assignments */
	/* NB: should NOT do globbing! "export v=/bin/c*; env \| grep ^v=" outputs
	* "v=/bin/c" /
@@ -2465,7 +2533,7 @@ static char expand_string_to_string(const char str)

	argv[0] = (char*)str;
	argv[1] = NULL;
-	list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
+	list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
	if (HUSH_DEBUG)
	if (!list[0] \|\| list[1])
	bb_error_msg_and_die("BUG in varexp2");
@@ -2875,8 +2943,8 @@ static void free_pipe(struct pipe *pi)
	}
	/* not "else if": on syntax error, we may have both! */
	if (command->group) {
-	debug_printf_clean(" begin group (grp_type:%d)\n",
-	command->grp_type);
+	debug_printf_clean(" begin group (cmd_type:%d)\n",
+	command->cmd_type);
	free_pipe_list(command->group);
	debug_printf_clean(" end group\n");
	command->group = NULL;
@@ -3688,7 +3756,7 @@ static int run_pipe(struct pipe *pi)

	if (pi->num_cmds != 1
	\|\| pi->followup == PIPE_BG
-	\|\| command->grp_type == GRP_SUBSHELL
+	\|\| command->cmd_type == CMD_SUBSHELL
	) {
	goto must_fork;
	}
@@ -3700,7 +3768,7 @@ static int run_pipe(struct pipe *pi)

	if (command->group) {
	#if ENABLE_HUSH_FUNCTIONS
-	if (command->grp_type == GRP_FUNCTION) {
+	if (command->cmd_type == CMD_FUNCDEF) {
	/* "executing" func () { list } */
	struct function *funcp;

@@ -3770,7 +3838,18 @@ 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);
+	if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
+	argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
+	}
+	#ifdef CMD_SINGLEWORD_NOGLOB_COND
+	else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
+	argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
+
+	}
+	#endif
+	else {
+	argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
+	}

	x = find_builtin(argv_expanded[0]);
	#if ENABLE_HUSH_FUNCTIONS
@@ -4012,7 +4091,7 @@ static void debug_print_tree(struct pipe *pi, int lvl)
	[RES_XXXX ] = "XXXX" ,
	[RES_SNTX ] = "SNTX" ,
	};
-	static const char *const GRPTYPE[] = {
+	static const char *const CMDTYPE[] = {
	"{}",
	"()",
	#if ENABLE_HUSH_FUNCTIONS
@@ -4036,7 +4115,7 @@ static void debug_print_tree(struct pipe *pi, int lvl)
	command->assignment_cnt);
	if (command->group) {
	fprintf(stderr, " group %s: (argv=%p)\n",
-	GRPTYPE[command->grp_type],
+	CMDTYPE[command->cmd_type],
	argv);
	debug_print_tree(command->group, lvl+1);
	prn++;
@@ -4649,7 +4728,7 @@ static int reserved_word(o_string word, struct parse_context ctx)
	debug_printf_parse("pop stack %p\n", ctx->stack);
	old = ctx->stack;
	old->command->group = ctx->list_head;
-	old->command->grp_type = GRP_NORMAL;
+	old->command->cmd_type = CMD_NORMAL;
	#if !BB_MMU
	o_addstr(&old->as_string, ctx->as_string.data);
	o_free_unsafe(&ctx->as_string);
@@ -4745,6 +4824,19 @@ static int done_word(o_string word, struct parse_context ctx)
	(ctx->ctx_res_w == RES_SNTX));
	return (ctx->ctx_res_w == RES_SNTX);
	}
+	# ifdef CMD_SINGLEWORD_NOGLOB_COND
+	if (strcmp(word->data, "export") == 0
+	# if ENABLE_HUSH_LOCAL
+	\|\| strcmp(word->data, "local") == 0
+	# endif
+	) {
+	command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
+	} else
+	# endif
+	if (strcmp(word->data, "[[") == 0) {
+	command->cmd_type = CMD_SINGLEWORD_NOGLOB;
+	}
+	/* fall through */
	}
	#endif
	if (command->group) {
@@ -5189,7 +5281,7 @@ static int parse_group(o_string dest, struct parse_context ctx,
	return 1;
	}
	nommu_addchr(&ctx->as_string, ch);
-	command->grp_type = GRP_FUNCTION;
+	command->cmd_type = CMD_FUNCDEF;
	goto skip;
	}
	#endif
@@ -5209,7 +5301,7 @@ static int parse_group(o_string dest, struct parse_context ctx,
	endch = '}';
	if (ch == '(') {
	endch = ')';
-	command->grp_type = GRP_SUBSHELL;
+	command->cmd_type = CMD_SUBSHELL;
	} else {
	/* bash does not allow "{echo...", requires whitespace */
	ch = i_getch(input);

shell/hush_test/hush-bugs/export_exp.right+7 -0

@@ -0,0 +1,7 @@
+	aa0 bb0
+	a=aa0 b=bb0
+	aa1 bb1
+	a=aa1 b=bb1
+	zzz=zzz
+	zz=*
+	Done

shell/hush_test/hush-bugs/export_exp.tests+19 -0

@@ -0,0 +1,19 @@
+	v="a=aa0 b=bb0"
+	# only 1st arg should be expanded in multiple words
+	export $v c=$v
+	echo $a $b
+	echo $c
+
+	# only 1st arg should be expanded in multiple words
+	export `echo a=aa1 b=bb1` c=`echo a=aa1 b=bb1`
+	echo $a $b
+	echo $c
+
+	>zz=zz
+	>zzz=zzz
+	# only 1st arg should be globbed
+	export zzz* zz=*
+	env \| grep ^zz \| sort
+	rm -rf zz=zz zzz=zzz
+
+	echo Done