hush: add support for set -x

function                                             old     new   delta
run_pipe                                            1442    1568    +126
dump_cmd_in_x_mode                                     -     126    +126
builtin_trap                                         441     462     +21
pseudo_exec_argv                                     171     187     +16
reset_traps_to_defaults                              214     229     +15
check_and_run_traps                                  227     232      +5
hush_exit                                             98     101      +3
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 6/0 up/down: 312/0)             Total: 312 bytes

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

1 files changed, 39 insertions, 1 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 14f8f2422..7640bd6ba 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -532,6 +532,7 @@ struct globals {
         smallint flag_return_in_progress;
 #endif
         smallint fake_mode;
+        smallint x_mode;
         smallint exiting; /* used to prevent EXIT trap recursion */
         /* These four support $?, $#, and $1 */
         smalluint last_exitcode;
@@ -3692,6 +3693,31 @@ static void execvp_or_die(char **argv)
         _exit(127); /* bash compat */
 }
 
+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;
+
+                len = 3;
+                n = 0;
+                while (argv[n])
+                        len += strlen(argv[n++]) + 1;
+                buf = xmalloc(len);
+                buf[0] = '+';
+                p = buf + 1;
+                n = 0;
+                while (argv[n])
+                        p += sprintf(p, " %s", argv[n++]);
+                *p++ = '\n';
+                *p = '\0';
+                fputs(buf, stderr);
+                free(buf);
+        }
+}
+
 #if BB_MMU
 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
         pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
@@ -3714,6 +3740,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
         char **new_env;
 
         new_env = expand_assignments(argv, assignment_cnt);
+        dump_cmd_in_x_mode(new_env);
 
         if (!argv[assignment_cnt]) {
                 /* Case when we are here: ... | var=val | ...
@@ -3742,6 +3769,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
                 nommu_save->argv = argv;
 #endif
         }
+        dump_cmd_in_x_mode(argv);
 
 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
         if (strchr(argv[0], '/') != NULL)
@@ -4239,13 +4267,19 @@ static NOINLINE int run_pipe(struct pipe *pi)
                         rcode = setup_redirects(command, squirrel);
                         restore_redirects(squirrel);
                         /* Set shell variables */
+                        if (G.x_mode)
+                                bb_putchar_stderr('+');
                         while (*argv) {
                                 p = expand_string_to_string(*argv);
+                                if (G.x_mode)
+                                        fprintf(stderr, " %s", p);
                                 debug_printf_exec("set shell var:'%s'->'%s'\n",
                                                 *argv, p);
                                 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
                                 argv++;
                         }
+                        if (G.x_mode)
+                                bb_putchar_stderr('\n');
                         /* Redirect error sets $? to 1. Otherwise,
                          * if evaluating assignment value set $?, retain it.
                          * Try "false; q=`exit 2`; echo $?" - should print 2: */
@@ -4305,6 +4339,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
                         rcode = setup_redirects(command, squirrel);
                         if (rcode == 0) {
                                 new_env = expand_assignments(argv, command->assignment_cnt);
+                                dump_cmd_in_x_mode(new_env);
+                                dump_cmd_in_x_mode(argv_expanded);
                                 old_vars = set_vars_and_save_old(new_env);
                                 if (!funcp) {
                                         debug_printf_exec(": builtin '%s' '%s'...\n",
@@ -4346,6 +4382,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
                                 rcode = setup_redirects(command, squirrel);
                                 if (rcode == 0) {
                                         new_env = expand_assignments(argv, command->assignment_cnt);
+                                        dump_cmd_in_x_mode(new_env);
+                                        dump_cmd_in_x_mode(argv_expanded);
                                         old_vars = set_vars_and_save_old(new_env);
                                         debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
                                                 argv_expanded[0], argv_expanded[1]);
@@ -6932,7 +6970,7 @@ static int set_mode(const char cstate, const char mode)
         int state = (cstate == '-' ? 1 : 0);
         switch (mode) {
                 case 'n': G.fake_mode = state; break;
-                case 'x': /*G.debug_mode = state;*/ break;
+                case 'x': G.x_mode = state; break;
                 default:  return EXIT_FAILURE;
         }
         return EXIT_SUCCESS;