Exception handling

src/main.c

@@ -17,7 +17,8 @@ int main(int argc, const char **argv) {
     ReadStream s;
     read_stream_init(&s, src, src_len);
     LispVal *r;
-    CONDITION_CASE(
+    bool had_toplevel_error = false;
+    HANDLER_BIND1(
         LIST(Qt),
         {
             while ((r = read(&s))) {
@@ -29,9 +30,23 @@ int main(int argc, const char **argv) {
             Fprint_condition(EXCEPTION_NAME(), EXCEPTION_DATA(),
                              Qerror_write_byte); //
             fprintf(stderr, "\nBacktrace (toplevel comes last):\n");
+            LispVal *backtrace = Fbacktrace();
+            DOLIST(frame, backtrace) {
+                LispVal *name = FIRST(frame);
+                bool evaled = !NILP(THIRD(frame));
+                LispVal *args = FOURTH(frame);
+                fprintf(stderr, " %c ", evaled ? '-' : '*');
+                Fprinc(name, Qerror_write_byte);
+                Fprinc(args, Qerror_write_byte);
+                fputc('\n', stderr);
+            }
+            CLEAR_EXCEPTION();
+            had_toplevel_error = true;
+            goto toplevel_error;
         });
+toplevel_error:
     unwind_to(toplevel);
     lisp_shutdown();
     free(src);
-    return 0;
+    return had_toplevel_error ? EXIT_FAILURE : EXIT_SUCCESS;
 }