py: Add traceback info to syntax errors.

Should fix issue #463.

py/builtinevex.c

@@ -25,13 +25,16 @@ STATIC mp_obj_t parse_compile_execute(mp_obj_t o_in, mp_parse_input_kind_t parse
     // parse the string
     mp_parse_error_kind_t parse_error_kind;
     mp_parse_node_t pn = mp_parse(lex, parse_input_kind, &parse_error_kind);
-    mp_lexer_free(lex);
 
     if (pn == MP_PARSE_NODE_NULL) {
         // parse error; raise exception
-        nlr_raise(mp_parse_make_exception(parse_error_kind));
+        mp_obj_t exc = mp_parse_make_exception(lex, parse_error_kind);
+        mp_lexer_free(lex);
+        nlr_raise(exc);
     }
 
+    mp_lexer_free(lex);
+
     // compile the string
     mp_obj_t module_fun = mp_compile(pn, source_name, MP_EMIT_OPT_NONE, false);
     mp_parse_node_free(pn);

py/builtinimport.c

@@ -100,15 +100,18 @@ void do_load(mp_obj_t module_obj, vstr_t *file) {
     // parse the imported script
     mp_parse_error_kind_t parse_error_kind;
     mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_error_kind);
-    mp_lexer_free(lex);
 
     if (pn == MP_PARSE_NODE_NULL) {
         // parse error; clean up and raise exception
+        mp_obj_t exc = mp_parse_make_exception(lex, parse_error_kind);
+        mp_lexer_free(lex);
         mp_locals_set(old_locals);
         mp_globals_set(old_globals);
-        nlr_raise(mp_parse_make_exception(parse_error_kind));
+        nlr_raise(exc);
     }
 
+    mp_lexer_free(lex);
+
     // compile the imported script
     mp_obj_t module_fun = mp_compile(pn, source_name, MP_EMIT_OPT_NONE, false);
     mp_parse_node_free(pn);

py/parsehelper.c

@@ -38,20 +38,30 @@ void mp_parse_show_exception(mp_lexer_t *lex, mp_parse_error_kind_t parse_error_
     }
 }
 
-mp_obj_t mp_parse_make_exception(mp_parse_error_kind_t parse_error_kind) {
-    // TODO add source file and line number to exception?
+mp_obj_t mp_parse_make_exception(mp_lexer_t *lex, mp_parse_error_kind_t parse_error_kind) {
+    // make exception object
+    mp_obj_t exc;
     switch (parse_error_kind) {
         case MP_PARSE_ERROR_MEMORY:
-            return mp_obj_new_exception_msg(&mp_type_MemoryError, STR_MEMORY);
+            exc = mp_obj_new_exception_msg(&mp_type_MemoryError, STR_MEMORY);
+            break;
 
         case MP_PARSE_ERROR_UNEXPECTED_INDENT:
-            return mp_obj_new_exception_msg(&mp_type_IndentationError, STR_UNEXPECTED_INDENT);
+            exc = mp_obj_new_exception_msg(&mp_type_IndentationError, STR_UNEXPECTED_INDENT);
+            break;
 
         case MP_PARSE_ERROR_UNMATCHED_UNINDENT:
-            return mp_obj_new_exception_msg(&mp_type_IndentationError, STR_UNMATCHED_UNINDENT);
+            exc = mp_obj_new_exception_msg(&mp_type_IndentationError, STR_UNMATCHED_UNINDENT);
+            break;
 
         case MP_PARSE_ERROR_INVALID_SYNTAX:
         default:
-            return mp_obj_new_exception_msg(&mp_type_SyntaxError, STR_INVALID_SYNTAX);
+            exc = mp_obj_new_exception_msg(&mp_type_SyntaxError, STR_INVALID_SYNTAX);
+            break;
     }
+
+    // add traceback to give info about file name and location
+    mp_obj_exception_add_traceback(exc, mp_lexer_source_name(lex), mp_lexer_cur(lex)->src_line, mp_lexer_cur(lex)->src_column);
+
+    return exc;
 }

py/parsehelper.h

@@ -1,2 +1,2 @@
 void mp_parse_show_exception(mp_lexer_t *lex, mp_parse_error_kind_t parse_error_kind);
-mp_obj_t mp_parse_make_exception(mp_parse_error_kind_t parse_error_kind);
+mp_obj_t mp_parse_make_exception(mp_lexer_t *lex, mp_parse_error_kind_t parse_error_kind);