hush: make syntax error messages a bit more useful

1 files changed, 37 insertions, 29 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 1545b041f..579950ff9 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -423,11 +423,20 @@ enum { run_list_level = 0 };
 #define B_NOSPAC 1
 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 
-static void __syntax(int line)
+#if 1
+/* Normal */
+static void syntax(const char *msg)
+{
+        bb_error_msg(msg ? "%s: %s" : "syntax error", "syntax error", msg);
+}
+#else
+/* Debug */
+static void syntax_lineno(int line)
 {
         bb_error_msg("syntax error hush.c:%d", line);
 }
-#define syntax() __syntax(__LINE__)
+#define syntax(str) syntax_lineno(__LINE__)
+#endif
 
 /* Index of subroutines: */
 /*   function prototypes for builtins */
@@ -1981,7 +1990,7 @@ static int run_list_real(struct pipe *pi)
                 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
                  && (rpipe->next == NULL)
                 ) {
-                        syntax(); /* unterminated FOR (no IN or no commands after IN) */
+                        syntax("malformed for"); /* no IN or no commands after IN */
                         debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level);
                         return 1;
                 }
@@ -1989,7 +1998,7 @@ static int run_list_real(struct pipe *pi)
                  || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
                 ) {
                         /* TODO: what is tested in the first condition? */
-                        syntax(); /* 2nd: malformed FOR (not followed by IN) */
+                        syntax("malformed for"); /* 2nd condition: not followed by IN */
                         debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level);
                         return 1;
                 }
@@ -2914,7 +2923,7 @@ static int reserved_word(o_string *dest, struct p_context *ctx)
                         debug_printf("push stack\n");
 #if ENABLE_HUSH_LOOPS
                         if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
-                                syntax();
+                                syntax("malformed for"); /* example: 'for if' */
                                 ctx->res_w = RES_SNTX;
                                 b_reset(dest);
                                 return 1;
@@ -2925,7 +2934,7 @@ static int reserved_word(o_string *dest, struct p_context *ctx)
                         initialize_context(ctx);
                         ctx->stack = new;
                 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
-                        syntax();
+                        syntax(NULL);
                         ctx->res_w = RES_SNTX;
                         b_reset(dest);
                         return 1;
@@ -2968,7 +2977,7 @@ static int done_word(o_string *dest, struct p_context *ctx)
                 glob_target = &ctx->pending_redirect->word;
         } else {
                 if (child->group) {
-                        syntax();
+                        syntax(NULL);
                         debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
                         return 1;
                 }
@@ -3224,21 +3233,15 @@ static int parse_group(o_string *dest, struct p_context *ctx,
 
         debug_printf_parse("parse_group entered\n");
         if (child->argv) {
-                syntax();
+                syntax(NULL);
                 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 = "}";
+        if (ch == '(') {
                 endch = ")";
                 child->subshell = 1;
-                break;
-        case '{':
-                endch = "}";
-                break;
-        default:
-                syntax();   /* really logic error */
         }
         rcode = parse_stream(dest, &sub, input, endch);
         done_word(dest, &sub); /* finish off the final word in the subcontext */
@@ -3307,7 +3310,7 @@ static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *i
                         while (1) {
                                 ch = b_getch(input);
                                 if (ch == EOF) {
-                                        syntax();
+                                        syntax("unterminated ${name}");
                                         debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
                                         return 1;
                                 }
@@ -3368,7 +3371,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                  || (m != CHAR_SPECIAL && dest->quote)
                 ) {
                         if (ch == EOF) {
-                                syntax();
+                                syntax("unterminated \"");
                                 debug_printf_parse("parse_stream return 1: unterminated \"\n");
                                 return 1;
                         }
@@ -3412,7 +3415,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         break;
                 case '\\':
                         if (next == EOF) {
-                                syntax();
+                                syntax("\\<eof>");
                                 debug_printf_parse("parse_stream return 1: \\<eof>\n");
                                 return 1;
                         }
@@ -3434,7 +3437,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                                 b_addchr(dest, ch);
                         }
                         if (ch == EOF) {
-                                syntax();
+                                syntax("unterminated '");
                                 debug_printf_parse("parse_stream return 1: unterminated '\n");
                                 return 1;
                         }
@@ -3455,11 +3458,14 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         if (next == '>') {
                                 redir_style = REDIRECT_APPEND;
                                 b_getch(input);
-                        } else if (next == '(') {
-                                syntax();   /* until we support >(list) Process Substitution */
+                        }
+#if 0
+                        else if (next == '(') {
+                                syntax(">(process) not supported");
                                 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
                                 return 1;
                         }
+#endif
                         setup_redirect(ctx, redir_fd, redir_style, input);
                         break;
                 case '<':
@@ -3472,11 +3478,14 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         } else if (next == '>') {
                                 redir_style = REDIRECT_IO;
                                 b_getch(input);
-                        } else if (next == '(') {
-                                syntax();   /* until we support <(list) Process Substitution */
+                        }
+#if 0
+                        else if (next == '(') {
+                                syntax("<(process) not supported");
                                 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
                                 return 1;
                         }
+#endif
                         setup_redirect(ctx, redir_fd, redir_style, input);
                         break;
                 case ';':
@@ -3513,13 +3522,12 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
                         break;
                 case ')':
                 case '}':
-                        syntax();   /* Proper use of this character is caught by end_trigger */
+                        syntax("unexpected }");   /* 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;
+                        if (ENABLE_HUSH_DEBUG)
+                                bb_error_msg_and_die("BUG: unexpected %c\n", ch);
                 }
         }
         /* Complain if quote?  No, maybe we just finished a command substitution
@@ -3585,7 +3593,7 @@ static int parse_and_run_stream(struct in_str *inp, int parse_flag)
                  * TEST should be printed */
                 rcode = parse_stream(&temp, &ctx, inp, ";\n");
                 if (rcode != 1 && ctx.old_flag != 0) {
-                        syntax();
+                        syntax(NULL);
                 }
                 if (rcode != 1 && ctx.old_flag == 0) {
                         done_word(&temp, &ctx);