hush: support "for v; do ... done" syntax (implied 'in "$@"')

3 files changed, 38 insertions, 14 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 2c1d31c6d..f38f3752b 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -508,7 +508,7 @@ static void syntax(const char *msg)
 /* Debug */
 static void syntax_lineno(int line)
 {
-        void (*fp)(const char *s, ...);
+        void FAST_FUNC (*fp)(const char *s, ...);
 
         fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
         fp("syntax error hush.c:%d", line);
@@ -2026,11 +2026,12 @@ static int run_list(struct pipe *pi)
                         debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
                         return 1;
                 }
-                if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
-                 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
+                if (/* Extra statement after IN: "for a in a b; echo Hi; do ...; done" ? */
+                    (rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
+                /* FOR not followed by IN or DO ("for var; do..." case)? */
+                 || (rpipe->res_word == RES_FOR && (rpipe->next->res_word != RES_IN && rpipe->next->res_word != RES_DO))
                 ) {
-                        /* TODO: what is tested in the first condition? */
-                        syntax("malformed for"); /* 2nd condition: FOR not followed by IN */
+                        syntax("malformed for");
                         debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
                         return 1;
                 }
@@ -2116,12 +2117,25 @@ static int run_list(struct pipe *pi)
                 if (rword == RES_FOR && pi->num_progs) {
                         if (!for_lcur) {
                                 /* first loop through for */
-                                /* if no variable values after "in" we skip "for" */
-                                if (!pi->next->progs->argv)
-                                        continue;
+
+                                static const char encoded_dollar_at[] ALIGN1 = {
+                                        SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
+                                }; /* encoded representation of "$@" */
+                                static const char *const encoded_dollar_at_argv[] = {
+                                        encoded_dollar_at, NULL
+                                }; /* argv list with one element: "$@" */
+                                char **vals;
+
+                                vals = (char**)encoded_dollar_at_argv;
+                                if (rpipe->next->res_word == RES_IN) {
+                                        /* if no variable values after "in" we skip "for" */
+                                        if (!pi->next->progs->argv)
+                                                continue;
+                                        vals = pi->next->progs->argv;
+                                } /* else: "for var; do..." -> assume "$@" list */
                                 /* create list of variable values */
-                                debug_print_strings("for_list made from", pi->next->progs->argv);
-                                for_list = expand_strvec_to_strvec(pi->next->progs->argv);
+                                debug_print_strings("for_list made from", vals);
+                                for_list = expand_strvec_to_strvec(vals);
                                 debug_print_strings("for_list", for_list);
                                 for_lcur = for_list;
                                 for_varname = pi->progs->argv[0];
@@ -2707,7 +2721,7 @@ static void unset_local_var(const char *name)
         }
 }
 
-/* the src parameter allows us to peek forward to a possible &n syntax
+/* The src parameter allows us to peek forward to a possible &n syntax
  * for file descriptor duplication, e.g., "2>&1".
  * Return code is 0 normally, 1 if a syntax error is detected in src.
  * Resource errors (in xmalloc) cause the process to exit */
@@ -2824,7 +2838,7 @@ static int reserved_word(const o_string *word, struct p_context *ctx)
                 { "fi",    RES_FI,    FLAG_END  },
 #endif
 #if ENABLE_HUSH_LOOPS
-                { "for",   RES_FOR,   FLAG_IN | FLAG_START },
+                { "for",   RES_FOR,   FLAG_IN | FLAG_DO | FLAG_START },
                 { "while", RES_WHILE, FLAG_DO | FLAG_START },
                 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
                 { "in",    RES_IN,    FLAG_DO   },
@@ -2936,12 +2950,12 @@ static int done_word(o_string *word, struct p_context *ctx)
                         }
                 }
 #endif
-                if (word->nonnull /* word had "xx" or 'xx' at least as part of it */
+                if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
                  /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
                  && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
                  /* (otherwise it's "abc".... and is already safe) */
                 ) {
-                        /* but exclude "$@"! it expands to no word despite "" */
+                        /* but exclude "$@" - it expands to no word despite "" */
                         char *p = word->data;
                         while (p[0] == SPECIAL_VAR_SYMBOL
                             && (p[1] & 0x7f) == '@'
diff --git a/shell/hush_test/hush-misc/empty_for2.right b/shell/hush_test/hush-misc/empty_for2.right
new file mode 100644
index 000000000..1acee9eb8
--- /dev/null
+++ b/shell/hush_test/hush-misc/empty_for2.right
@@ -0,0 +1,4 @@
+PARAM:abc
+PARAM:d e
+PARAM:123
+OK: 0
diff --git a/shell/hush_test/hush-misc/empty_for2.tests b/shell/hush_test/hush-misc/empty_for2.tests
new file mode 100755
index 000000000..2b12ec2c1
--- /dev/null
+++ b/shell/hush_test/hush-misc/empty_for2.tests
@@ -0,0 +1,6 @@
+if test $# = 0; then
+    exec "$THIS_SH" $0 abc "d e" 123
+fi
+false
+for v; do echo "PARAM:$v"; done
+echo OK: $?