hush: support "break N" and "continue N"

fix non-detection of builtins and applets in "v=break; ...; $v; ..." case add testsuite entries for the above function old new delta builtin_break 12 93 +81 run_list 1948 1971 +23 builtin_continue 12 21 +9 pseudo_exec_argv 132 138 +6 builtin_exec 23 25 +2 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 5/0 up/down: 121/0) Total: 121 bytes
author: Denis Vlasenko <vda.linux@googlemail.com> 2008-07-28 23:07:06 +0000
committer: Denis Vlasenko <vda.linux@googlemail.com> 2008-07-28 23:07:06 +0000
commit: 6a2d40f239566e886ef76542a75662cee9380a0e (patch)
tree: f2e26f50cae7ddc60112f51174c4d994a9954fea /shell
parent: bcb25537d02b50ce26678defcf4f39d0c89f5b3b (diff)
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7 files changed, 82 insertions, 35 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 21cb36564..a74fe4730 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -440,6 +440,7 @@ struct globals {
        smalluint last_return_code;
        char **global_argv;
        int global_argc;
+        unsigned depth_break_continue;
        pid_t last_bg_pid;
        const char *ifs;
        const char *cwd;
@@ -487,7 +488,8 @@ enum { run_list_level = 0 };
 #define global_argc      (G.global_argc     )
 #define last_return_code (G.last_return_code)
 #define ifs              (G.ifs             )
-#define flag_break_continue (G.flag_break_continue)
+#define flag_break_continue  (G.flag_break_continue )
+#define depth_break_continue (G.depth_break_continue)
 #define fake_mode        (G.fake_mode       )
 #define cwd              (G.cwd             )
 #define last_bg_pid      (G.last_bg_pid     )
@@ -552,11 +554,11 @@ static int free_pipe(struct pipe *pi, int indent);
 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 static int run_list(struct pipe *pi);
 #if BB_MMU
-#define pseudo_exec_argv(ptrs2free, argv)  pseudo_exec_argv(argv)
+#define pseudo_exec_argv(ptrs2free, argv, argv_expanded) pseudo_exec_argv(argv, argv_expanded)
-#define      pseudo_exec(ptrs2free, child)      pseudo_exec(child)
+#define      pseudo_exec(ptrs2free, child, argv_expanded)     pseudo_exec(child, argv_expanded)
 #endif
-static void pseudo_exec_argv(char **ptrs2free, char **argv) NORETURN;
+static void pseudo_exec_argv(char **ptrs2free, char **argv, char **argv_expanded) NORETURN;
-static void pseudo_exec(char **ptrs2free, struct child_prog *child) NORETURN;
+static void pseudo_exec(char **ptrs2free, struct child_prog *child, char **argv_expanded) NORETURN;
 static int run_pipe(struct pipe *pi);
 /*   data structure manipulation: */
 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
@@ -1410,7 +1412,7 @@ static void restore_redirects(int squirrel[])
 * XXX no exit() here.  If you don't exec, use _exit instead.
 * The at_exit handlers apparently confuse the calling process,
 * in particular stdin handling.  Not sure why? -- because of vfork! (vda) */
-static void pseudo_exec_argv(char **ptrs2free, char **argv)
+static void pseudo_exec_argv(char **ptrs2free, char **argv, char **argv_expanded)
 {
        int i, rcode;
        char *p;
@@ -1432,10 +1434,14 @@ static void pseudo_exec_argv(char **ptrs2free, char **argv)
        if (!argv[0])
                _exit(EXIT_SUCCESS);
-        argv = expand_strvec_to_strvec(argv);
+        if (argv_expanded) {
+                argv = argv_expanded;
+        } else {
+                argv = expand_strvec_to_strvec(argv);
 #if !BB_MMU
-        *ptrs2free++ = (char*) argv;
+                *ptrs2free++ = (char*) argv;
 #endif
+        }
        /*
         * Check if the command matches any of the builtins.
@@ -1479,10 +1485,10 @@ static void pseudo_exec_argv(char **ptrs2free, char **argv)
 /* Called after [v]fork() in run_pipe()
 */
-static void pseudo_exec(char **ptrs2free, struct child_prog *child)
+static void pseudo_exec(char **ptrs2free, struct child_prog *child, char **argv_expanded)
 {
        if (child->argv)
-                pseudo_exec_argv(ptrs2free, child->argv);
+                pseudo_exec_argv(ptrs2free, child->argv, argv_expanded);
        if (child->group) {
 #if !BB_MMU
@@ -1760,14 +1766,16 @@ static int run_pipe(struct pipe *pi)
        int nextin;
        int pipefds[2];         /* pipefds[0] is for reading */
        struct child_prog *child;
+        char **argv_expanded = NULL;
+        char **argv;
        const struct built_in_command *x;
        char *p;
        /* it is not always needed, but we aim to smaller code */
        int squirrel[] = { -1, -1, -1 };
        int rcode;
-        const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
+        const int single_and_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
-        debug_printf_exec("run_pipe start: single_fg=%d\n", single_fg);
+        debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
 #if ENABLE_HUSH_JOB
        pi->pgrp = -1;
@@ -1780,7 +1788,7 @@ static int run_pipe(struct pipe *pi)
         * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
         */
        child = &(pi->progs[0]);
-        if (single_fg && child->group && child->subshell == 0) {
+        if (single_and_fg && child->group && child->subshell == 0) {
                debug_printf("non-subshell grouping\n");
                setup_redirects(child, squirrel);
                debug_printf_exec(": run_list\n");
@@ -1791,41 +1799,45 @@ static int run_pipe(struct pipe *pi)
                return rcode;
        }
-        if (single_fg && child->argv != NULL) {
+        argv = child->argv;
-                char **argv_expanded;
-                char **argv = child->argv;
+        if (single_and_fg && argv != NULL) {
                for (i = 0; is_assignment(argv[i]); i++)
                        continue;
                if (i != 0 && argv[i] == NULL) {
-                        /* assignments, but no command: set the local environment */
+                        /* assignments, but no command: set local environment */
                        for (i = 0; argv[i] != NULL; i++) {
                                debug_printf("local environment set: %s\n", argv[i]);
                                p = expand_string_to_string(argv[i]);
                                set_local_var(p, 0);
                        }
-                        return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
+                        return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
                }
+                /* Expand assignments into one string each */
                for (i = 0; is_assignment(argv[i]); i++) {
                        p = expand_string_to_string(argv[i]);
                        putenv(p);
 //FIXME: do we leak p?!
                }
+                /* Expand the rest into (possibly) many strings each */
+                argv_expanded = expand_strvec_to_strvec(argv + i);
                for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
-                        if (strcmp(argv[i], x->cmd) == 0) {
+                        if (strcmp(argv_expanded[0], x->cmd) == 0) {
-                                if (x->function == builtin_exec && argv[i+1] == NULL) {
+                                if (x->function == builtin_exec && argv_expanded[1] == NULL) {
                                        debug_printf("magic exec\n");
                                        setup_redirects(child, NULL);
                                        return EXIT_SUCCESS;
                                }
-                                debug_printf("builtin inline %s\n", argv[0]);
+                                debug_printf("builtin inline %s\n", argv_expanded[0]);
                                /* XXX setup_redirects acts on file descriptors, not FILEs.
                                 * This is perfect for work that comes after exec().
                                 * Is it really safe for inline use?  Experimentally,
                                 * things seem to work with glibc. */
                                setup_redirects(child, squirrel);
-                                debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
+                                debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
-                                argv_expanded = expand_strvec_to_strvec(argv + i);
                                rcode = x->function(argv_expanded) & 0xff;
                                free(argv_expanded);
                                restore_redirects(squirrel);
@@ -1836,12 +1848,10 @@ static int run_pipe(struct pipe *pi)
                }
 #if ENABLE_FEATURE_SH_STANDALONE
                {
-                        int a = find_applet_by_name(argv[i]);
+                        int a = find_applet_by_name(argv_expanded[0]);
                        if (a >= 0 && APPLET_IS_NOFORK(a)) {
                                setup_redirects(child, squirrel);
                                save_nofork_data(&nofork_save);
-                                argv_expanded = argv + i;
-                                argv_expanded = expand_strvec_to_strvec(argv + i);
                                debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
                                rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded);
                                free(argv_expanded);
@@ -1854,6 +1864,10 @@ static int run_pipe(struct pipe *pi)
 #endif
        }
+        /* NB: argv_expanded may already be created, and that
+         * might include `cmd` runs! Do not rerun it! We *must*
+         * use argv_expanded if it's non-NULL */
        /* Disable job control signals for shell (parent) and
         * for initial child code after fork */
        set_jobctrl_sighandler(SIG_IGN);
@@ -1914,8 +1928,10 @@ static int run_pipe(struct pipe *pi)
                        set_jobctrl_sighandler(SIG_DFL);
                        set_misc_sighandler(SIG_DFL);
                        signal(SIGCHLD, SIG_DFL);
-                        pseudo_exec(ptrs2free, child); /* does not return */
+                        pseudo_exec(ptrs2free, child, argv_expanded); /* does not return */
                }
+                free(argv_expanded);
+                argv_expanded = NULL;
 #if !BB_MMU
                free_strings(ptrs2free);
 #endif
@@ -2236,18 +2252,22 @@ static int run_list(struct pipe *pi)
                                /* we only ran a builtin: rcode is already known
                                 * and we don't need to wait for anything. */
                                /* was it "break" or "continue"? */
                                if (flag_break_continue) {
                                        smallint fbc = flag_break_continue;
                                        /* we might fall into outer *loop*,
                                         * don't want to break it too */
-                                        flag_break_continue = 0;
                                        if (loop_top) {
-                                                if (fbc == BC_BREAK)
+                                                depth_break_continue--;
+                                                if (depth_break_continue == 0)
+                                                        flag_break_continue = 0;
+                                                if (depth_break_continue != 0 || fbc == BC_BREAK)
                                                        goto check_jobs_and_break;
                                                /* "continue": simulate end of loop */
                                                rword = RES_DONE;
                                                continue;
                                        }               
+                                        flag_break_continue = 0;
                                        bb_error_msg("break/continue: only meaningful in a loop");
                                        /* bash compat: exit code is still 0 */
                                }
@@ -4265,7 +4285,7 @@ static int builtin_exec(char **argv)
                char **ptrs2free = alloc_ptrs(argv);
 #endif
 // FIXME: if exec fails, bash does NOT exit! We do...
-                pseudo_exec_argv(ptrs2free, argv + 1);
+                pseudo_exec_argv(ptrs2free, argv + 1, NULL);
                /* never returns */
        }
 }
@@ -4512,14 +4532,23 @@ static int builtin_unset(char **argv)
        return EXIT_SUCCESS;
 }
-static int builtin_break(char **argv UNUSED_PARAM)
+static int builtin_break(char **argv)
 {
-        flag_break_continue = BC_BREAK;
+        flag_break_continue++; /* BC_BREAK = 1 */
+        depth_break_continue = 1;
+        if (argv[1]) {
+                depth_break_continue = bb_strtou(argv[1], NULL, 10);
+                if (errno || !depth_break_continue || argv[2]) {
+                        bb_error_msg("bad arguments");
+                        flag_break_continue = BC_BREAK;
+                        depth_break_continue = UINT_MAX;
+                }
+        }
        return EXIT_SUCCESS;
 }
-static int builtin_continue(char **argv UNUSED_PARAM)
+static int builtin_continue(char **argv)
 {
-        flag_break_continue = BC_CONTINUE;
+        flag_break_continue++; /* BC_CONTINUE = 2 = 1+1 */
-        return EXIT_SUCCESS;
+        return builtin_break(argv);
 }
diff --git a/shell/hush_test/hush-misc/break1.right b/shell/hush_test/hush-misc/break1.right
new file mode 100644
index 000000000..04a4b1757
--- /dev/null
+++ b/shell/hush_test/hush-misc/break1.right
@@ -0,0 +1,2 @@
+A
+OK:0
diff --git a/shell/hush_test/hush-misc/break1.tests b/shell/hush_test/hush-misc/break1.tests
new file mode 100755
index 000000000..912f149c1
--- /dev/null
+++ b/shell/hush_test/hush-misc/break1.tests
@@ -0,0 +1,3 @@
+while true; do echo A; break; echo B; done
+echo OK:$?
diff --git a/shell/hush_test/hush-misc/break2.right b/shell/hush_test/hush-misc/break2.right
new file mode 100644
index 000000000..8a15cb95f
--- /dev/null
+++ b/shell/hush_test/hush-misc/break2.right
@@ -0,0 +1,3 @@
+A
+AA
+OK:0
diff --git a/shell/hush_test/hush-misc/break2.tests b/shell/hush_test/hush-misc/break2.tests
new file mode 100755
index 000000000..7da9faf34
--- /dev/null
+++ b/shell/hush_test/hush-misc/break2.tests
@@ -0,0 +1,6 @@
+while true; do
+    echo A
+    while true; do echo AA; break 2; echo BB; done
+    echo B
+done
+echo OK:$?
diff --git a/shell/hush_test/hush-misc/break3.right b/shell/hush_test/hush-misc/break3.right
new file mode 100644
index 000000000..04a4b1757
--- /dev/null
+++ b/shell/hush_test/hush-misc/break3.right
@@ -0,0 +1,2 @@
+A
+OK:0
diff --git a/shell/hush_test/hush-misc/break3.tests b/shell/hush_test/hush-misc/break3.tests
new file mode 100755
index 000000000..d138dcac5
--- /dev/null
+++ b/shell/hush_test/hush-misc/break3.tests
@@ -0,0 +1,2 @@
+v=break; while true; do echo A; $v; echo B; break; echo C; done
+echo OK:$?
author	Denis Vlasenko <vda.linux@googlemail.com>	2008-07-28 23:07:06 +0000
committer	Denis Vlasenko <vda.linux@googlemail.com>	2008-07-28 23:07:06 +0000
commit	6a2d40f239566e886ef76542a75662cee9380a0e (patch)
tree	f2e26f50cae7ddc60112f51174c4d994a9954fea /shell
parent	bcb25537d02b50ce26678defcf4f39d0c89f5b3b (diff)
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