hush: fix multimple dependent variable expansion cases
authorDenys Vlasenko <vda.linux@googlemail.com>
Fri, 16 Jul 2010 11:52:32 +0000 (13:52 +0200)
committerDenys Vlasenko <vda.linux@googlemail.com>
Fri, 16 Jul 2010 11:52:32 +0000 (13:52 +0200)
function                                             old     new   delta
get_local_var_value                                  100     171     +71
expand_assignments                                    46      76     +30
reset_traps_to_defaults                              229     238      +9
maybe_set_to_sigexit                                  47      50      +3
init_sigmasks                                        211     214      +3
builtin_trap                                         462     465      +3
expand_vars_to_list                                 2412    2408      -4
run_pipe                                            1568    1533     -35
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/2 up/down: 119/-39)            Total: 80 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
shell/hush.c
shell/hush_test/hush-vars/var_serial.right [new file with mode: 0644]
shell/hush_test/hush-vars/var_serial.tests [new file with mode: 0755]

index c67aebdd75daa21621b09813ba0f4a9f7a35138f..c5a8ea6171be79fe2e5e340ec6db6c04adeafc15 100644 (file)
 //config:      default y
 //config:      depends on HUSH
 //config:      help
-//config:        This instructs hush to print commands before execution. Adds ~300 bytes.
+//config:        This instructs hush to print commands before execution.
+//config:        Adds ~300 bytes.
 //config:
 
 //usage:#define hush_trivial_usage NOUSAGE_STR
@@ -664,7 +665,7 @@ struct globals {
        smallint n_mode;
 #if ENABLE_HUSH_MODE_X
        smallint x_mode;
-# define G_x_mode G.x_mode
+# define G_x_mode (G.x_mode)
 #else
 # define G_x_mode 0
 #endif
@@ -688,6 +689,7 @@ struct globals {
        const char *cwd;
        struct variable *top_var; /* = &G.shell_ver (set in main()) */
        struct variable shell_ver;
+       char **expanded_assignments;
 #if ENABLE_HUSH_FUNCTIONS
        struct function *top_func;
 # if ENABLE_HUSH_LOCAL
@@ -1459,9 +1461,23 @@ static struct variable *get_local_var(const char *name)
 
 static const char* FAST_FUNC get_local_var_value(const char *name)
 {
-       struct variable **pp = get_ptr_to_local_var(name);
-       if (pp)
-               return strchr((*pp)->varstr, '=') + 1;
+       struct variable **vpp;
+
+       if (G.expanded_assignments) {
+               char **cpp = G.expanded_assignments;
+               int len = strlen(name);
+               while (*cpp) {
+                       char *cp = *cpp;
+                       if (strncmp(cp, name, len) == 0 && cp[len] == '=')
+                               return cp + len + 1;
+                       cpp++;
+               }
+       }
+
+       vpp = get_ptr_to_local_var(name);
+       if (vpp)
+               return strchr((*vpp)->varstr, '=') + 1;
+
        if (strcmp(name, "PPID") == 0)
                return utoa(G.root_ppid);
        // bash compat: UID? EUID?
@@ -3090,11 +3106,14 @@ static char* expand_strvec_to_string(char **argv)
 static char **expand_assignments(char **argv, int count)
 {
        int i;
-       char **p = NULL;
+       char **p;
+
+       G.expanded_assignments = p = NULL;
        /* Expand assignments into one string each */
        for (i = 0; i < count; i++) {
-               p = add_string_to_strings(p, expand_string_to_string(argv[i]));
+               G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i]));
        }
+       G.expanded_assignments = NULL;
        return p;
 }
 
@@ -4316,6 +4335,27 @@ static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
  * backgrounded: cmd &     { list } &
  * subshell:     ( list ) [&]
  */
+#if !ENABLE_HUSH_MODE_X
+#define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \
+       redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
+#endif
+static int redirect_and_varexp_helper(char ***new_env_p, struct variable **old_vars_p, struct command *command, int squirrel[3], char **argv_expanded)
+{
+       /* 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. */
+       int rcode = setup_redirects(command, squirrel);
+       if (rcode == 0) {
+               char **new_env = expand_assignments(command->argv, command->assignment_cnt);
+               *new_env_p = new_env;
+               dump_cmd_in_x_mode(new_env);
+               dump_cmd_in_x_mode(argv_expanded);
+               if (old_vars_p)
+                       *old_vars_p = set_vars_and_save_old(new_env);
+       }
+       return rcode;
+}
 static NOINLINE int run_pipe(struct pipe *pi)
 {
        static const char *const null_ptr = NULL;
@@ -4325,7 +4365,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
        struct command *command;
        char **argv_expanded;
        char **argv;
-       char *p;
        /* it is not always needed, but we aim to smaller code */
        int squirrel[] = { -1, -1, -1 };
        int rcode;
@@ -4402,19 +4441,45 @@ static NOINLINE int run_pipe(struct pipe *pi)
                if (argv[command->assignment_cnt] == NULL) {
                        /* Assignments, but no command */
                        /* Ensure redirects take effect (that is, create files).
-                        * Try "a=t >file": */
+                        * Try "a=t >file" */
+#if 0 /* A few cases in testsuite fail with this code. FIXME */
+                       rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
+                       /* Set shell variables */
+                       if (new_env) {
+                               argv = new_env;
+                               while (*argv) {
+                                       set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
+                                       /* Do we need to flag set_local_var() errors?
+                                        * "assignment to readonly var" and "putenv error"
+                                        */
+                                       argv++;
+                               }
+                       }
+                       /* Redirect error sets $? to 1. Otherwise,
+                        * if evaluating assignment value set $?, retain it.
+                        * Try "false; q=`exit 2`; echo $?" - should print 2: */
+                       if (rcode == 0)
+                               rcode = G.last_exitcode;
+                       /* Exit, _skipping_ variable restoring code: */
+                       goto clean_up_and_ret0;
+
+#else /* Older, bigger, but more correct code */
+
                        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);
+                               char *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);
+                               /* Do we need to flag set_local_var() errors?
+                                * "assignment to readonly var" and "putenv error"
+                                */
                                argv++;
                        }
                        if (G_x_mode)
@@ -4424,13 +4489,11 @@ static NOINLINE int run_pipe(struct pipe *pi)
                         * Try "false; q=`exit 2`; echo $?" - should print 2: */
                        if (rcode == 0)
                                rcode = G.last_exitcode;
-                       /* Do we need to flag set_local_var() errors?
-                        * "assignment to readonly var" and "putenv error"
-                        */
                        IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
                        debug_leave();
                        debug_printf_exec("run_pipe: return %d\n", rcode);
                        return rcode;
+#endif
                }
 
                /* Expand the rest into (possibly) many strings each */
@@ -4471,16 +4534,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
                                        goto clean_up_and_ret1;
                                }
                        }
-                       /* 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. */
-                       rcode = setup_redirects(command, squirrel);
+                       rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
                        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",
                                                x->b_cmd, argv_expanded[1]);
@@ -4504,9 +4559,10 @@ static NOINLINE int run_pipe(struct pipe *pi)
 #endif
                        }
  clean_up_and_ret:
-                       restore_redirects(squirrel);
                        unset_vars(new_env);
                        add_vars(old_vars);
+/* clean_up_and_ret0: */
+                       restore_redirects(squirrel);
  clean_up_and_ret1:
                        free(argv_expanded);
                        IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
@@ -4518,12 +4574,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
                if (ENABLE_FEATURE_SH_STANDALONE) {
                        int n = find_applet_by_name(argv_expanded[0]);
                        if (n >= 0 && APPLET_IS_NOFORK(n)) {
-                               rcode = setup_redirects(command, squirrel);
+                               rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
                                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]);
                                        rcode = run_nofork_applet(n, argv_expanded);
diff --git a/shell/hush_test/hush-vars/var_serial.right b/shell/hush_test/hush-vars/var_serial.right
new file mode 100644 (file)
index 0000000..42aa330
--- /dev/null
@@ -0,0 +1,5 @@
+Assignments only: c=a
+Assignments and a command: c=a
+Assignments and a builtin: c=a
+Assignments and a function: c=a
+Done
diff --git a/shell/hush_test/hush-vars/var_serial.tests b/shell/hush_test/hush-vars/var_serial.tests
new file mode 100755 (executable)
index 0000000..6b4a4cd
--- /dev/null
@@ -0,0 +1,22 @@
+a=a
+
+b=b
+c=c
+# Second assignment depends on the first:
+b=$a c=$b
+echo Assignments only: c=$c
+
+b=b
+c=c
+b=$a c=$b "$THIS_SH" -c 'echo Assignments and a command: c=$c'
+
+b=b
+c=c
+b=$a c=$b eval 'echo Assignments and a builtin: c=$c'
+
+b=b
+c=c
+f() { echo Assignments and a function: c=$c; }
+b=$a c=$b f
+
+echo Done