hush: fix "set -x" output prefix overlapping for v="..`cmd`.." case

Was printing initial "+" prefix for the assignment, that printing

	"+ cmd"

then printing the expanded " v=VAL" string.

Delay printing of "+" prefix for the assignment to after expansion.

function                                             old     new   delta
run_pipe                                            1883    1902     +19
builtin_eval                                         127     133      +6
expand_vars_to_list                                 1103    1106      +3
dump_cmd_in_x_mode                                   144     142      -2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/1 up/down: 28/-2)              Total: 26 bytes

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

diff --git a/shell/hush.c b/shell/hush.c
index 1ac2db3814250f60892a82b7ff8420320add392f..e9212cefca7ec5b8763b159c3d6c4abd8a5019ef 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -896,7 +896,6 @@ 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
@@ -955,6 +954,9 @@ struct globals {
        unsigned func_nest_level; /* solely to prevent "local v" in non-functions */
 # endif
        struct function *top_func;
+#endif
+#if ENABLE_HUSH_MODE_X
+       unsigned x_mode_depth;
 #endif
        /* Signal and trap handling */
 #if ENABLE_HUSH_FAST
@@ -7247,6 +7249,7 @@ static int generate_stream_from_string(const char *s, pid_t *pid_p)
                CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
                reset_traps_to_defaults();
                IF_HUSH_MODE_X(G.x_mode_depth++;)
+               //bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth);
                parse_and_run_string(s);
                _exit(G.last_exitcode);
 # else
@@ -8032,17 +8035,16 @@ static void dump_cmd_in_x_mode(char **argv)
        if (G_x_mode && argv) {
                /* We want to output the line in one write op */
                char *buf, *p;
-               int len;
-               int n;
+               unsigned len;
+               unsigned n;
 
-               len = G.x_mode_depth + 3; /* "+[+++...]<cmd...>\n\0" */
+               len = G.x_mode_depth + 3; /* "+[+++...][ cmd...]\n\0" */
                n = 0;
                while (argv[n])
                        len += strlen(argv[n++]) + 1;
                p = buf = xmalloc(len);
                n = G.x_mode_depth;
-               while (n-- >= 0)
-                       *p++ = '+';
+               do *p++ = '+'; while ((int)(--n) >= 0);
                n = 0;
                while (argv[n])
                        p += sprintf(p, " %s", argv[n++]);
@@ -8835,21 +8837,23 @@ static NOINLINE int run_pipe(struct pipe *pi)
                        restore_redirects(squirrel);
 
                        /* Set shell variables */
-#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],
                                                EXP_FLAG_ESC_GLOB_CHARS,
                                                /*unbackslash:*/ 1
                                );
-                               if (G_x_mode)
+#if ENABLE_HUSH_MODE_X
+                               if (G_x_mode) {
+                                       if (i == 0) {
+                                               unsigned n = G.x_mode_depth;
+                                               do
+                                                       bb_putchar_stderr('+');
+                                               while ((int)(--n) >= 0);
+                                       }
                                        fprintf(stderr, " %s", p);
+                               }
+#endif
                                debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p);
                                if (set_local_var(p, /*flag:*/ 0)) {
                                        /* assignment to readonly var / putenv error? */
@@ -10246,6 +10250,7 @@ static int FAST_FUNC builtin_eval(char **argv)
                return EXIT_SUCCESS;
 
        IF_HUSH_MODE_X(G.x_mode_depth++;)
+       //bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth);
        if (!argv[1]) {
                /* bash:
                 * eval "echo Hi; done" ("done" is syntax error):
@@ -10276,6 +10281,7 @@ static int FAST_FUNC builtin_eval(char **argv)
                free(str);
        }
        IF_HUSH_MODE_X(G.x_mode_depth--;)
+       //bb_error_msg("%s: --x_mode_depth=%d", __func__, G.x_mode_depth);
        return G.last_exitcode;
 }