Add parser cleanup to vhdlpp

This commit adds removal of global objects in
the execution of vhdlpp. This includes deleting
design entities and the global parse scope.

vhdlpp/main.cc

@@ -56,6 +56,7 @@ const char*dump_design_entities_path = 0;
 const char*dump_libraries_path = 0;
 
 extern void dump_libraries(ostream&file);
+extern void parser_cleanup();
 
 static void process_debug_token(const char*word)
 {
@@ -141,21 +142,25 @@ int main(int argc, char*argv[])
 	    dump_design_entities(file);
       }
 
-      if (errors > 0)
+      if (errors > 0) {
+        parser_cleanup();
 	    return 2;
+      }
 
       errors = elaborate_entities();
       if (errors > 0) {
 	    fprintf(stderr, "%d errors elaborating design.\n", errors);
+        parser_cleanup();
 	    return 3;
       }
 
       errors = emit_entities();
       if (errors > 0) {
 	    fprintf(stderr, "%d errors emitting design.\n", errors);
+        parser_cleanup();
 	    return 4;
       }
 
-      lex_strings.cleanup();
+      parser_cleanup();
       return 0;
 }

vhdlpp/parse.y

@@ -100,6 +100,31 @@ void preload_global_types(void)
       generate_global_types(active_scope);
 }
 
+//Remove the scope created at the beginning of parser's work.
+//After the parsing active_scope should keep it's address
+
+static void delete_global_scope(void)
+{
+    active_scope->destroy_global_scope();
+    delete active_scope;
+}
+
+//delete global entities that were gathered over the parsing process 
+static void delete_design_entities(void)
+{
+      for(map<perm_string,Entity*>::iterator cur = design_entities.begin()
+      ; cur != design_entities.end(); ++cur)
+        delete cur->second;
+}
+
+//clean the mess caused by the parser
+void parser_cleanup(void)
+{
+    delete_design_entities();
+    delete_global_scope();
+    lex_strings.cleanup();
+}
+
 const VType*parse_type_by_name(perm_string name)
 {
       return active_scope->find_type(name);