hush: 'return' should have effect earlier

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/shell/hush.c b/shell/hush.c
index 3c4621f672c90585574147549691772e9ef9a102..8693d7562e1366ec64dd01daadebd7c0307de036 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -777,6 +777,9 @@ struct globals {
         * 1: return is invoked, skip all till end of func
         */
        smallint flag_return_in_progress;
+# define G_flag_return_in_progress (G.flag_return_in_progress)
+#else
+# define G_flag_return_in_progress 0
 #endif
        smallint exiting; /* used to prevent EXIT trap recursion */
        /* These four support $?, $#, and $1 */
@@ -1736,6 +1739,7 @@ static int check_and_run_traps(void)
                break;
  got_sig:
                if (G.traps && G.traps[sig]) {
+                       debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
                        if (G.traps[sig][0]) {
                                /* We have user-defined handler */
                                smalluint save_rcode;
@@ -1753,6 +1757,7 @@ static int check_and_run_traps(void)
                /* not a trap: special action */
                switch (sig) {
                case SIGINT:
+                       debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
                        /* Builtin was ^C'ed, make it look prettier: */
                        bb_putchar('\n');
                        G.flag_SIGINT = 1;
@@ -1761,6 +1766,7 @@ static int check_and_run_traps(void)
 #if ENABLE_HUSH_JOB
                case SIGHUP: {
                        struct pipe *job;
+                       debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
                        /* bash is observed to signal whole process groups,
                         * not individual processes */
                        for (job = G.job_list; job; job = job->next) {
@@ -1775,6 +1781,7 @@ static int check_and_run_traps(void)
 #endif
 #if ENABLE_HUSH_FAST
                case SIGCHLD:
+                       debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
                        G.count_SIGCHLD++;
 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
                        /* Note:
@@ -1784,6 +1791,7 @@ static int check_and_run_traps(void)
                        break;
 #endif
                default: /* ignored: */
+                       debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
                        /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
                        /* Note:
                         * We dont do 'last_sig = sig' here -> NOT returning this sig.
@@ -6078,10 +6086,8 @@ static void parse_and_run_stream(struct in_str *inp, int end_trigger)
                debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
                run_and_free_list(pipe_list);
                empty = 0;
-#if ENABLE_HUSH_FUNCTIONS
-               if (G.flag_return_in_progress == 1)
+               if (G_flag_return_in_progress == 1)
                        break;
-#endif
        }
 }
 
@@ -6641,8 +6647,8 @@ static int run_function(const struct function *funcp, char **argv)
        save_and_replace_G_args(&sv, argv);
 
        /* "we are in function, ok to use return" */
-       sv_flg = G.flag_return_in_progress;
-       G.flag_return_in_progress = -1;
+       sv_flg = G_flag_return_in_progress;
+       G_flag_return_in_progress = -1;
 # if ENABLE_HUSH_LOCAL
        G.func_nest_level++;
 # endif
@@ -6683,7 +6689,7 @@ static int run_function(const struct function *funcp, char **argv)
                G.func_nest_level--;
        }
 # endif
-       G.flag_return_in_progress = sv_flg;
+       G_flag_return_in_progress = sv_flg;
 
        restore_G_args(&sv, argv);
 
@@ -7707,6 +7713,8 @@ static int run_list(struct pipe *pi)
        for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
                if (G.flag_SIGINT)
                        break;
+               if (G_flag_return_in_progress == 1)
+                       break;
 
                IF_HAS_KEYWORDS(rword = pi->res_word;)
                debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
@@ -7877,12 +7885,10 @@ static int run_list(struct pipe *pi)
                                        continue;
                                }
 #endif
-#if ENABLE_HUSH_FUNCTIONS
-                               if (G.flag_return_in_progress == 1) {
+                               if (G_flag_return_in_progress == 1) {
                                        checkjobs(NULL);
                                        break;
                                }
-#endif
                        } else if (pi->followup == PIPE_BG) {
                                /* What does bash do with attempts to background builtins? */
                                /* even bash 3.2 doesn't do that well with nested bg:
@@ -9271,9 +9277,9 @@ static int FAST_FUNC builtin_source(char **argv)
        }
 
 #if ENABLE_HUSH_FUNCTIONS
-       sv_flg = G.flag_return_in_progress;
+       sv_flg = G_flag_return_in_progress;
        /* "we are inside sourced file, ok to use return" */
-       G.flag_return_in_progress = -1;
+       G_flag_return_in_progress = -1;
 #endif
        if (argv[1])
                save_and_replace_G_args(&sv, argv);
@@ -9286,7 +9292,7 @@ static int FAST_FUNC builtin_source(char **argv)
        if (argv[1])
                restore_G_args(&sv, argv);
 #if ENABLE_HUSH_FUNCTIONS
-       G.flag_return_in_progress = sv_flg;
+       G_flag_return_in_progress = sv_flg;
 #endif
 
        return G.last_exitcode;
@@ -9509,12 +9515,12 @@ static int FAST_FUNC builtin_return(char **argv)
 {
        int rc;
 
-       if (G.flag_return_in_progress != -1) {
+       if (G_flag_return_in_progress != -1) {
                bb_error_msg("%s: not in a function or sourced script", argv[0]);
                return EXIT_FAILURE; /* bash compat */
        }
 
-       G.flag_return_in_progress = 1;
+       G_flag_return_in_progress = 1;
 
        /* bash:
         * out of range: wraps around at 256, does not error out

diff --git a/shell/hush_test/hush-trap/return_in_trap1.right b/shell/hush_test/hush-trap/return_in_trap1.right
new file mode 100644 (file)
index 0000000..a6e6378
--- /dev/null
+++ b/shell/hush_test/hush-trap/return_in_trap1.right
@@ -0,0 +1,4 @@
+a:2
+b:0
+Trap
+d:3

diff --git a/shell/hush_test/hush-trap/return_in_trap1.tests b/shell/hush_test/hush-trap/return_in_trap1.tests
new file mode 100755 (executable)
index 0000000..f249802
--- /dev/null
+++ b/shell/hush_test/hush-trap/return_in_trap1.tests
@@ -0,0 +1,18 @@
+a() {
+       (exit 2)
+       echo a:$?
+       (kill -s USR1 $$; echo b:$?; exit 3)
+       echo c:$?       # does not execute
+       (exit 4)
+}
+
+trap "echo Trap; return" USR1
+a
+
+echo d:$?
+# It's debatable what is the correct value above.
+# Does 'return' in trap sees $? == 2 or $? == 3?
+# IOW: after (kill..), does shell first wait for its completion
+# and sets $?, then checks pending signals and runs a trap handler,
+# or does it first checks pending signals and runs handler?
+# hush does the former, and prints 3.