4 files changed, 186 insertions, 94 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 1e7429cb1..cc5802c30 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -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++) {
diff --git a/shell/hush.c b/shell/hush.c
index f34fdd402..e82766093 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -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;
 }
 
diff --git a/shell/lash_unused.c b/shell/lash_unused.c
index 21ea5471b..2574987c5 100644
--- a/shell/lash_unused.c
+++ b/shell/lash_unused.c
@@ -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++) {
diff --git a/shell/msh.c b/shell/msh.c
index dffacf02a..fe85a8170 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -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");