hush: improve set -x: make "+++" indent level increase in `cmd` and eval.

function                                             old     new   delta
dump_cmd_in_x_mode                                   126     144     +18
run_pipe                                            1873    1883     +10
builtin_eval                                         119     127      +8
expand_vars_to_list                                 1100    1103      +3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 39/0)               Total: 39 bytes

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

1 files changed, 19 insertions, 9 deletions

diff --git a/shell/hush.c b/shell/hush.c
index e3c6e2de9..02fb1b5ef 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -896,6 +896,7 @@ struct globals {
 
         char o_opt[NUM_OPT_O];
 #if ENABLE_HUSH_MODE_X
+        smalluint x_mode_depth;
 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
 #else
 # define G_x_mode 0
@@ -7182,11 +7183,8 @@ static int generate_stream_from_string(const char *s, pid_t *pid_p)
                         + (1 << SIGTTIN)
                         + (1 << SIGTTOU)
                         , SIG_IGN);
-                CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
                 close(channel[0]); /* NB: close _first_, then move fd! */
                 xmove_fd(channel[1], 1);
-                /* Prevent it from trying to handle ctrl-z etc */
-                IF_HUSH_JOB(G.run_list_level = 1;)
 # if ENABLE_HUSH_TRAP
                 /* Awful hack for `trap` or $(trap).
                  *
@@ -7233,7 +7231,11 @@ static int generate_stream_from_string(const char *s, pid_t *pid_p)
                 }
 # endif
 # if BB_MMU
+                /* Prevent it from trying to handle ctrl-z etc */
+                IF_HUSH_JOB(G.run_list_level = 1;)
+                CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
                 reset_traps_to_defaults();
+                IF_HUSH_MODE_X(G.x_mode_depth++;)
                 parse_and_run_string(s);
                 _exit(G.last_exitcode);
 # else
@@ -8022,13 +8024,14 @@ static void dump_cmd_in_x_mode(char **argv)
                 int len;
                 int n;
 
-                len = 3;
+                len = G.x_mode_depth + 3; /* "+[+++...]<cmd...>\n\0" */
                 n = 0;
                 while (argv[n])
                         len += strlen(argv[n++]) + 1;
-                buf = xmalloc(len);
-                buf[0] = '+';
-                p = buf + 1;
+                p = buf = xmalloc(len);
+                n = G.x_mode_depth;
+                while (n-- >= 0)
+                        *p++ = '+';
                 n = 0;
                 while (argv[n])
                         p += sprintf(p, " %s", argv[n++]);
@@ -8821,8 +8824,13 @@ static NOINLINE int run_pipe(struct pipe *pi)
                         restore_redirects(squirrel);
 
                         /* Set shell variables */
-                        if (G_x_mode)
-                                bb_putchar_stderr('+');
+#if ENABLE_HUSH_MODE_X
+                        if (G_x_mode) {
+                                int n = G.x_mode_depth;
+                                while (n-- >= 0)
+                                        bb_putchar_stderr('+');
+                        }
+#endif
                         i = 0;
                         while (i < command->assignment_cnt) {
                                 char *p = expand_string_to_string(argv[i],
@@ -10226,6 +10234,7 @@ static int FAST_FUNC builtin_eval(char **argv)
         if (!argv[0])
                 return EXIT_SUCCESS;
 
+        IF_HUSH_MODE_X(G.x_mode_depth++;)
         if (!argv[1]) {
                 /* bash:
                  * eval "echo Hi; done" ("done" is syntax error):
@@ -10255,6 +10264,7 @@ static int FAST_FUNC builtin_eval(char **argv)
                 parse_and_run_string(str);
                 free(str);
         }
+        IF_HUSH_MODE_X(G.x_mode_depth--;)
         return G.last_exitcode;
 }