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

author: Denis Vlasenko <vda.linux@googlemail.com> 2007-05-03 22:45:39 +0000
committer: Denis Vlasenko <vda.linux@googlemail.com> 2007-05-03 22:45:39 +0000
commit: e725bfe6e01505f0480dd1bd357209d3a2e72bb7 (patch)
tree: 3e128376a43debb087230efdd9bd73fb7a7f3be0 /shell/hush.c
parent: f2fffd0014edff7f791fc2a5b27147bb0628d7e6 (diff)
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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);
+                        debug_printf_parse(": checking %s for reserved-ness\n", dest->data);
-                        if (reserved_word(dest, ctx))
+                        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
+                        /* If we aren't performing a substitution, treat
-                         * command separator.  */
+                         * a newline as a command separator.
-                        if (end_trigger != '\0' && ch == '\n')
+                         * [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) {
+                if ((end_trigger && strchr(end_trigger, ch))
-                        debug_printf("leaving parse_stream (triggered)\n");
+                 && !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");
+        debug_printf_parse("parse_stream return -%d\n", end_trigger != NULL);
-        if (end_trigger != '\0')
+        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 */
+        memset(map, MAP_ORDINARY, sizeof(map)); /* most chars flow through always */
-        mapset("\\$'\"`", 3);        /* never flow through */
+        mapset("\\$'\"`", MAP_NEVER_FLOWTROUGH);
-        mapset("<>;&|(){}#", 1);     /* flow through if quoted */
+        mapset("<>;&|(){}#", MAP_FLOWTROUGH_IF_QUOTED);
-        mapset(ifs, 2);              /* also flow through 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();
                }
author	Denis Vlasenko <vda.linux@googlemail.com>	2007-05-03 22:45:39 +0000
committer	Denis Vlasenko <vda.linux@googlemail.com>	2007-05-03 22:45:39 +0000
commit	e725bfe6e01505f0480dd1bd357209d3a2e72bb7 (patch)
tree	3e128376a43debb087230efdd9bd73fb7a7f3be0 /shell/hush.c
parent	f2fffd0014edff7f791fc2a5b27147bb0628d7e6 (diff)
download	busybox-w32-e725bfe6e01505f0480dd1bd357209d3a2e72bb7.tar.gz busybox-w32-e725bfe6e01505f0480dd1bd357209d3a2e72bb7.tar.bz2 busybox-w32-e725bfe6e01505f0480dd1bd357209d3a2e72bb7.zip