hush: fix "true | exit 3; echo $?" bug

1 files changed, 92 insertions, 46 deletions

diff --git a/shell/hush.c b/shell/hush.c
index f3be78547..4d5e41244 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -89,6 +89,7 @@
 /* Finer-grained debug switch */
 #define debug_printf_jobs(...) do {} while (0)
 #define debug_printf_exec(...) do {} while (0)
+#define debug_printf_parse(...) do {} while (0)
 
 
 #ifndef debug_printf
@@ -111,6 +112,10 @@ static const char *indenter(int i)
 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
 #endif
 
+#ifndef debug_printf_parse
+#define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
+#endif
+
 
 #if !ENABLE_HUSH_INTERACTIVE
 #undef ENABLE_FEATURE_EDITING
@@ -259,8 +264,14 @@ static int last_return_code;
 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 
 /* "globals" within this file */
-static const char *ifs;
+enum {
+        MAP_ORDINARY             = 0,
+        MAP_FLOWTROUGH_IF_QUOTED = 1,
+        MAP_IFS_IF_UNQUOTED      = 2, /* flow through if quoted too */
+        MAP_NEVER_FLOWTROUGH     = 3,
+};
 static unsigned char map[256];
+static const char *ifs;
 static int fake_mode;
 static struct close_me *close_me_head;
 static const char *cwd;
@@ -390,13 +401,13 @@ static int done_pipe(struct p_context *ctx, pipe_style type);
 /*   primary string parsing: */
 static int redirect_dup_num(struct in_str *input);
 static int redirect_opt_num(o_string *o);
-static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
+static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end);
 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 static const char *lookup_param(const char *src);
 static char *make_string(char **inp);
 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
-static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
+static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
 /*   setup: */
 static int parse_stream_outer(struct in_str *inp, int flag);
 static int parse_string_outer(const char *s, int flag);
@@ -1977,8 +1988,9 @@ static int run_list_real(struct pipe *pi)
                         {
                                 rcode = checkjobs(pi);
                         }
-                        debug_printf("checkjobs returned %d\n", rcode);
+                        debug_printf_exec("checkjobs returned %d\n", rcode);
                 }
+                debug_printf_exec("setting last_return_code=%d\n", rcode);
                 last_return_code = rcode;
                 pi->num_progs = save_num_progs; /* restore number of programs */
                 if (rmode == RES_IF || rmode == RES_ELIF)
@@ -2519,7 +2531,7 @@ static int reserved_word(o_string *dest, struct p_context *ctx)
         return 0;
 }
 
-/* normal return is 0.
+/* Normal return is 0.
  * Syntax or xglob errors return 1. */
 static int done_word(o_string *dest, struct p_context *ctx)
 {
@@ -2527,9 +2539,9 @@ static int done_word(o_string *dest, struct p_context *ctx)
         glob_t *glob_target;
         int gr, flags = 0;
 
-        debug_printf("done_word: %s %p\n", dest->data, child);
+        debug_printf_parse("done_word: '%s' %p\n", dest->data, child);
         if (dest->length == 0 && !dest->nonnull) {
-                debug_printf("  true null, ignored\n");
+                debug_printf_parse("done_word return 0: true null, ignored\n");
                 return 0;
         }
         if (ctx->pending_redirect) {
@@ -2537,24 +2549,31 @@ static int done_word(o_string *dest, struct p_context *ctx)
         } else {
                 if (child->group) {
                         syntax();
-                        return 1;  /* syntax error, groups and arglists don't mix */
+                        debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
+                        return 1;
                 }
                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
-                        debug_printf("checking %s for reserved-ness\n", dest->data);
-                        if (reserved_word(dest, ctx))
+                        debug_printf_parse(": checking %s for reserved-ness\n", dest->data);
+                        if (reserved_word(dest, ctx)) {
+                                debug_printf_parse("done_word return %d\n", (ctx->w == RES_SNTX));
                                 return (ctx->w == RES_SNTX);
+                        }
                 }
                 glob_target = &child->glob_result;
                 if (child->argv) flags |= GLOB_APPEND;
         }
         gr = xglob(dest, flags, glob_target);
-        if (gr != 0) return 1;
+        if (gr != 0) {
+                debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
+                return 1;
+        }
 
         b_reset(dest);
         if (ctx->pending_redirect) {
                 ctx->pending_redirect = NULL;
                 if (glob_target->gl_pathc != 1) {
                         bb_error_msg("ambiguous redirect");
+                        debug_printf_parse("done_word return 1: ambiguous redirect\n");
                         return 1;
                 }
         } else {
@@ -2564,6 +2583,7 @@ static int done_word(o_string *dest, struct p_context *ctx)
                 done_word(dest, ctx);
                 done_pipe(ctx, PIPE_SEQ);
         }
+        debug_printf_parse("done_word return 0\n");
         return 0;
 }
 
@@ -2614,7 +2634,7 @@ static int done_pipe(struct p_context *ctx, pipe_style type)
 {
         struct pipe *new_p;
         done_command(ctx);  /* implicit closure of previous command */
-        debug_printf("done_pipe, type %d\n", type);
+        debug_printf_parse("done_pipe, type %d\n", type);
         ctx->pipe->followup = type;
         ctx->pipe->r_mode = ctx->w;
         new_p = new_pipe();
@@ -2710,7 +2730,8 @@ static FILE *generate_stream_from_list(struct pipe *head)
 
 /* this version hacked for testing purposes */
 /* return code is exit status of the process that is run. */
-static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
+static int process_command_subs(o_string *dest, struct p_context *ctx,
+        struct in_str *input, const char *subst_end)
 {
         int retcode;
         o_string result = NULL_O_STRING;
@@ -2732,7 +2753,7 @@ static int process_command_subs(o_string *dest, struct p_context *ctx, struct in
         setup_file_in_str(&pipe_str, p);
 
         /* now send results of command back into original context */
-        retcode = parse_stream(dest, ctx, &pipe_str, '\0');
+        retcode = parse_stream(dest, ctx, &pipe_str, NULL);
         /* XXX In case of a syntax error, should we try to kill the child?
          * That would be tough to do right, so just read until EOF. */
         if (retcode == 1) {
@@ -2757,21 +2778,25 @@ static int process_command_subs(o_string *dest, struct p_context *ctx, struct in
 static int parse_group(o_string *dest, struct p_context *ctx,
         struct in_str *input, int ch)
 {
-        int rcode, endch = 0;
+        int rcode;
+        const char *endch = NULL;
         struct p_context sub;
         struct child_prog *child = ctx->child;
+
+        debug_printf_parse("parse_group entered\n");
         if (child->argv) {
                 syntax();
-                return 1;  /* syntax error, groups and arglists don't mix */
+                debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
+                return 1;
         }
         initialize_context(&sub);
         switch (ch) {
         case '(':
-                endch = ')';
+                endch = ")";
                 child->subshell = 1;
                 break;
         case '{':
-                endch = '}';
+                endch = "}";
                 break;
         default:
                 syntax();   /* really logic error */
@@ -2780,6 +2805,8 @@ static int parse_group(o_string *dest, struct p_context *ctx,
         done_word(dest, &sub); /* finish off the final word in the subcontext */
         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
         child->group = sub.list_head;
+
+        debug_printf_parse("parse_group return %d\n", rcode);
         return rcode;
         /* child remains "open", available for possible redirects */
 }
@@ -2880,7 +2907,7 @@ static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *i
                         break;
                 case '(':
                         b_getch(input);
-                        process_command_subs(dest, ctx, input, ')');
+                        process_command_subs(dest, ctx, input, ")");
                         break;
                 case '*':
                         sep[0] = ifs[0];
@@ -2913,12 +2940,12 @@ static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
 {
         struct in_str foo;
         setup_string_in_str(&foo, src);
-        return parse_stream(dest, ctx, &foo, '\0');
+        return parse_stream(dest, ctx, &foo, NULL);
 }
 
 /* return code is 0 for normal exit, 1 for syntax error */
 static int parse_stream(o_string *dest, struct p_context *ctx,
-        struct in_str *input, int end_trigger)
+        struct in_str *input, const char *end_trigger)
 {
         int ch, m;
         int redir_fd;
@@ -2929,30 +2956,38 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
          * A single-quote triggers a bypass of the main loop until its mate is
          * found.  When recursing, quote state is passed in via dest->quote. */
 
-        debug_printf("parse_stream, end_trigger=%d\n", end_trigger);
+        debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
+
         while ((ch = b_getch(input)) != EOF) {
                 m = map[ch];
                 next = (ch == '\n') ? 0 : b_peek(input);
-                debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
+                debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
                                                 ch, ch, m, dest->quote);
-                if (m == 0 || ((m == 1 || m == 2) && dest->quote)) {
+                if (m == MAP_ORDINARY
+                 || (m != MAP_NEVER_FLOWTROUGH && dest->quote)
+                ) {
                         b_addqchr(dest, ch, dest->quote);
                         continue;
                 }
-                if (m == 2) {  /* unquoted IFS */
+                if (m == MAP_IFS_IF_UNQUOTED) {
                         if (done_word(dest, ctx)) {
+                                debug_printf_parse("parse_stream return 1\n");
                                 return 1;
                         }
-                        /* If we aren't performing a substitution, treat a newline as a
-                         * command separator.  */
-                        if (end_trigger != '\0' && ch == '\n')
+                        /* If we aren't performing a substitution, treat
+                         * a newline as a command separator.
+                         * [why we don't handle it exactly like ';'? --vda] */
+                        if (end_trigger && ch == '\n') {
                                 done_pipe(ctx, PIPE_SEQ);
+                        }
                 }
-                if (ch == end_trigger && !dest->quote && ctx->w == RES_NONE) {
-                        debug_printf("leaving parse_stream (triggered)\n");
+                if ((end_trigger && strchr(end_trigger, ch))
+                 && !dest->quote && ctx->w == RES_NONE
+                ) {
+                        debug_printf_parse("parse_stream return 0\n");
                         return 0;
                 }
-                if (m == 2)
+                if (m == MAP_IFS_IF_UNQUOTED)
                         continue;
                 switch (ch) {
                 case '#':
@@ -2970,13 +3005,17 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                 case '\\':
                         if (next == EOF) {
                                 syntax();
+                                debug_printf_parse("parse_stream return 1\n");
                                 return 1;
                         }
                         b_addqchr(dest, '\\', dest->quote);
                         b_addqchr(dest, b_getch(input), dest->quote);
                         break;
                 case '$':
-                        if (handle_dollar(dest, ctx, input) != 0) return 1;
+                        if (handle_dollar(dest, ctx, input) != 0) {
+                                debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
+                                return 1;
+                        }
                         break;
                 case '\'':
                         dest->nonnull = 1;
@@ -2988,6 +3027,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         }
                         if (ch == EOF) {
                                 syntax();
+                                debug_printf_parse("parse_stream return 1\n");
                                 return 1;
                         }
                         break;
@@ -2996,7 +3036,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         dest->quote = !dest->quote;
                         break;
                 case '`':
-                        process_command_subs(dest, ctx, input, '`');
+                        process_command_subs(dest, ctx, input, "`");
                         break;
                 case '>':
                         redir_fd = redirect_opt_num(dest);
@@ -3007,6 +3047,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                                 b_getch(input);
                         } else if (next == '(') {
                                 syntax();   /* until we support >(list) Process Substitution */
+                                debug_printf_parse("parse_stream return 1: >(process) not supported\n");
                                 return 1;
                         }
                         setup_redirect(ctx, redir_fd, redir_style, input);
@@ -3023,6 +3064,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                                 b_getch(input);
                         } else if (next == '(') {
                                 syntax();   /* until we support <(list) Process Substitution */
+                                debug_printf_parse("parse_stream return 1: <(process) not supported\n");
                                 return 1;
                         }
                         setup_redirect(ctx, redir_fd, redir_style, input);
@@ -3054,28 +3096,32 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         break;
                 case '(':
                 case '{':
-                        if (parse_group(dest, ctx, input, ch) != 0)
+                        if (parse_group(dest, ctx, input, ch) != 0) {
+                                debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
                                 return 1;
+                        }
                         break;
                 case ')':
                 case '}':
-                        syntax();   /* Proper use of this character caught by end_trigger */
+                        syntax();   /* Proper use of this character is caught by end_trigger */
+                        debug_printf_parse("parse_stream return 1: unexpected '}'\n");
                         return 1;
                 default:
                         syntax();   /* this is really an internal logic error */
+                        debug_printf_parse("parse_stream return 1: internal logic error\n");
                         return 1;
                 }
         }
-        /* complain if quote?  No, maybe we just finished a command substitution
+        /* Complain if quote?  No, maybe we just finished a command substitution
          * that was quoted.  Example:
          * $ echo "`cat foo` plus more"
          * and we just got the EOF generated by the subshell that ran "cat foo"
-         * The only real complaint is if we got an EOF when end_trigger != '\0',
+         * The only real complaint is if we got an EOF when end_trigger != NULL,
          * that is, we were really supposed to get end_trigger, and never got
          * one before the EOF.  Can't use the standard "syntax error" return code,
          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
-        debug_printf("leaving parse_stream (EOF)\n");
-        if (end_trigger != '\0')
+        debug_printf_parse("parse_stream return -%d\n", end_trigger != NULL);
+        if (end_trigger)
                 return -1;
         return 0;
 }
@@ -3097,17 +3143,17 @@ static void update_ifs_map(void)
          * The map[] array only really needs two bits each, and on most machines
          * that would be faster because of the reduced L1 cache footprint.
          */
-        memset(map, 0, sizeof(map)); /* most characters flow through always */
-        mapset("\\$'\"`", 3);        /* never flow through */
-        mapset("<>;&|(){}#", 1);     /* flow through if quoted */
-        mapset(ifs, 2);              /* also flow through if quoted */
+        memset(map, MAP_ORDINARY, sizeof(map)); /* most chars flow through always */
+        mapset("\\$'\"`", MAP_NEVER_FLOWTROUGH);
+        mapset("<>;&|(){}#", MAP_FLOWTROUGH_IF_QUOTED);
+        mapset(ifs, MAP_IFS_IF_UNQUOTED);  /* also flow through if quoted */
 }
 
 /* most recursion does not come through here, the exception is
  * from builtin_source() */
 static int parse_stream_outer(struct in_str *inp, int flag)
 {
-// FIXME: 'true | exit 3; echo $?' is parsed as a whole,
+// FIXME: '{ true | exit 3; echo $? }' is parsed as a whole,
 // as a result $? is replaced by 0, not 3!
 // Need to stop & execute stuff at ';', not parse till EOL!
 
@@ -3119,11 +3165,11 @@ static int parse_stream_outer(struct in_str *inp, int flag)
                 initialize_context(&ctx);
                 update_ifs_map();
                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING))
-                         mapset(";$&|", 0);
+                        mapset(";$&|", MAP_ORDINARY);
 #if ENABLE_HUSH_INTERACTIVE
                 inp->promptmode = 1;
 #endif
-                rcode = parse_stream(&temp, &ctx, inp, '\n');
+                rcode = parse_stream(&temp, &ctx, inp, ";\n");
                 if (rcode != 1 && ctx.old_flag != 0) {
                         syntax();
                 }