optimized js_parse_class_default_ctor() (bnoordhuis)

Author: Fabrice Bellard

quickjs-opcode.h

@@ -110,6 +110,7 @@ DEF( return, 1, 1, 0, none)
 DEF( return_undef, 1, 0, 0, none)
 DEF(check_ctor_return, 1, 1, 2, none)
 DEF( check_ctor, 1, 0, 0, none)
+DEF( init_ctor, 1, 0, 1, none)
 DEF( check_brand, 1, 2, 2, none) /* this_obj func -> this_obj func */
 DEF( add_brand, 1, 2, 0, none) /* this_obj home_obj -> */
 DEF( return_async, 1, 1, 0, none)

quickjs.c

@@ -16677,10 +16677,27 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
  BREAK;
  CASE(OP_check_ctor):
  if (JS_IsUndefined(new_target)) {
+ non_ctor_call:
  JS_ThrowTypeError(ctx, "class constructors must be invoked with 'new'");
  goto exception;
  }
  BREAK;
+ CASE(OP_init_ctor):
+ {
+ JSValue super, ret;
+ sf->cur_pc = pc;
+ if (JS_IsUndefined(new_target))
+ goto non_ctor_call;
+ super = JS_GetPrototype(ctx, func_obj);
+ if (JS_IsException(super))
+ goto exception;
+ ret = JS_CallConstructor2(ctx, super, new_target, argc, (JSValueConst *)argv);
+ JS_FreeValue(ctx, super);
+ if (JS_IsException(ret))
+ goto exception;
+ *sp++ = ret;
+ }
+ BREAK;
  CASE(OP_check_brand):
  {
  int ret = JS_CheckBrand(ctx, sp[-2], sp[-1]);
@@ -22714,45 +22731,73 @@ static __exception int js_parse_object_literal(JSParseState *s)
 #define PF_POW_FORBIDDEN (1 << 3)
 
 static __exception int js_parse_postfix_expr(JSParseState *s, int parse_flags);
+static void emit_class_field_init(JSParseState *s);
+static JSFunctionDef *js_new_function_def(JSContext *ctx,
+ JSFunctionDef *parent,
+ BOOL is_eval,
+ BOOL is_func_expr,
+ const char *filename, int line_num);
+static void emit_return(JSParseState *s, BOOL hasval);
 
 static __exception int js_parse_left_hand_side_expr(JSParseState *s)
 {
  return js_parse_postfix_expr(s, PF_POSTFIX_CALL);
 }
 
-/* XXX: could generate specific bytecode */
 static __exception int js_parse_class_default_ctor(JSParseState *s,
  BOOL has_super,
  JSFunctionDef **pfd)
 {
- JSParsePos pos;
- const char *str;
- int ret, line_num;
  JSParseFunctionEnum func_type;
- const uint8_t *saved_buf_end;
+ JSFunctionDef *fd = s->cur_func;
+ int idx;
 
- js_parse_get_pos(s, &pos);
+ fd = js_new_function_def(s->ctx, fd, FALSE, FALSE, s->filename,
+ s->token.line_num);
+ if (!fd)
+ return -1;
+
+ s->cur_func = fd;
+ fd->has_home_object = TRUE;
+ fd->super_allowed = TRUE;
+ fd->has_prototype = FALSE;
+ fd->has_this_binding = TRUE;
+ fd->new_target_allowed = TRUE;
+
+ push_scope(s); /* enter body scope */
+ fd->body_scope = fd->scope_level;
  if (has_super) {
- /* spec change: no argument evaluation */
- str = "(){super(...arguments);}";
+ fd->is_derived_class_constructor = TRUE;
+ fd->super_call_allowed = TRUE;
+ fd->arguments_allowed = TRUE;
+ fd->has_arguments_binding = TRUE;
  func_type = JS_PARSE_FUNC_DERIVED_CLASS_CONSTRUCTOR;
+ emit_op(s, OP_init_ctor);
+ // TODO(bnoordhuis) roll into OP_init_ctor
+ emit_op(s, OP_scope_put_var_init);
+ emit_atom(s, JS_ATOM_this);
+ emit_u16(s, 0);
+ emit_class_field_init(s);
  } else {
- str = "(){}";
  func_type = JS_PARSE_FUNC_CLASS_CONSTRUCTOR;
+ /* error if not invoked as a constructor */
+ emit_op(s, OP_check_ctor);
+ emit_class_field_init(s);
  }
- line_num = s->token.line_num;
- saved_buf_end = s->buf_end;
- s->buf_ptr = (uint8_t *)str;
- s->buf_end = (uint8_t *)(str + strlen(str));
- ret = next_token(s);
- if (!ret) {
- ret = js_parse_function_decl2(s, func_type, JS_FUNC_NORMAL,
- JS_ATOM_NULL, (uint8_t *)str,
- line_num, JS_PARSE_EXPORT_NONE, pfd);
- }
- s->buf_end = saved_buf_end;
- ret |= js_parse_seek_token(s, &pos);
- return ret;
+
+ fd->func_kind = JS_FUNC_NORMAL;
+ fd->func_type = func_type;
+ emit_return(s, FALSE);
+
+ s->cur_func = fd->parent;
+ if (pfd)
+ *pfd = fd;
+
+ /* the real object will be set at the end of the compilation */
+ idx = cpool_add(s, JS_NULL);
+ fd->parent_cpool_idx = idx;
+
+ return 0;
 }
 
 /* find field in the current scope */
@@ -25466,8 +25511,6 @@ static __exception int js_parse_cond_expr(JSParseState *s, int parse_flags)
  return 0;
 }
 
-static void emit_return(JSParseState *s, BOOL hasval);
-
 /* allowed parse_flags: PF_IN_ACCEPTED */
 static __exception int js_parse_assign_expr2(JSParseState *s, int parse_flags)
 {