From 79dcc1d553927759e5496c4519841bc68abd8704 Mon Sep 17 00:00:00 2001
From: pjh456 <147148383@qq.com>
Date: Sat, 26 Sep 2026 23:17:53 +0000
Subject: [PATCH] =?UTF-8?q?fix:=20RegExp=20flags=20getter=20=E5=AF=B9?=
 =?UTF-8?q?=E6=97=A0=E6=A7=BD=E5=AF=B9=E8=B1=A1=E6=8C=89=E8=A7=84=E8=8C=83?=
 =?UTF-8?q?=E8=AF=BB=E6=97=97=E8=AE=BF=E9=97=AE=E5=99=A8=E7=BB=84=E4=B8=B2?=
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---
 crates/oxide_builtins/src/regexp.rs           | 50 +++++++++++++++----
 .../oxide_vm/tests/builtins_regexp_tests.rs   | 21 ++++++++
 2 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/crates/oxide_builtins/src/regexp.rs b/crates/oxide_builtins/src/regexp.rs
index 3048dbe4..664f1577 100644
--- a/crates/oxide_builtins/src/regexp.rs
+++ b/crates/oxide_builtins/src/regexp.rs
@@ -999,22 +999,50 @@ pub fn regexp_get_unicode_sets<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResu
 }
 
 /// `RegExp.prototype.flags` getter：返回实例 flags 串。
+///
+/// 非对象 this 抛 TypeError；持编译正则槽的对象直接返槽串；其余对象
+/// （含 prototype 本身）无槽可返，按规范顺序读 8 个旗属性并以 ToBoolean
+/// 判位组串。
 pub fn regexp_get_flags<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     let this_val = vm.reg(args[0]);
-    // proto 恒等判定：规范对 prototype 本身返回 undefined。
-    if this_val.is_object() {
+    if !this_val.is_object() {
+        return NativeResult::Err(crate::error::create_type_error(vm, "RegExp.prototype method called on non-object"));
+    }
+    let this_ptr = this_val.as_js_object_ptr();
+    if this_ptr.is_null() {
+        return NativeResult::Err(crate::error::create_type_error(vm, "null object"));
+    }
+    // 持编译正则槽的对象直接返槽串。
+    // SAFETY: this_ptr 已确认非空对象值，借用即时消费。
+    if unsafe { &*this_ptr }.is_regexp_obj() {
+        // SAFETY: 同上，槽串由对象持有。
+        return NativeResult::Ok(unsafe { &*this_ptr }.get_regexp_flags());
+    }
+    // 无槽对象：按规范序（d,g,i,m,s,u,v,y）读 8 个旗属性，ToBoolean 判位
+    // 组串。每次读都可能触发用户 getter 重入（session GC 可搬移对象），
+    // 对象指针须每次读前从 this 寄存器（GC 根）重取。
+    let mut out: Vec<u16> = Vec::with_capacity(8);
+    for (name, unit) in [
+        ("hasIndices", 'd'),
+        ("global", 'g'),
+        ("ignoreCase", 'i'),
+        ("multiline", 'm'),
+        ("dotAll", 's'),
+        ("unicode", 'u'),
+        ("unicodeSets", 'v'),
+        ("sticky", 'y'),
+    ] {
+        let this_val = vm.reg(args[0]);
         let this_ptr = this_val.as_js_object_ptr();
-        let proto_ptr = vm.session().builtin_world().regexp_proto.as_ptr() as *mut JsObject;
-        if !this_ptr.is_null() && this_ptr == proto_ptr {
-            return NativeResult::Ok(JsValue::undefined());
+        let v = match rx_get_bool_prop(vm, this_ptr, name, this_val) {
+            Ok(v) => v,
+            Err(err) => return NativeResult::Err(err),
+        };
+        if v {
+            out.push(unit as u16);
         }
     }
-    let re_ptr = match get_regexp_ptr(vm, args) {
-        Ok(ptr) => ptr,
-        Err(err) => return NativeResult::Err(err),
-    };
-    let re = unsafe { &*re_ptr };
-    NativeResult::Ok(re.get_regexp_flags())
+    NativeResult::Ok(vm.new_string_units(&out))
 }
 
 /// `RegExp.prototype.source` getter：返回实例 source 串。
diff --git a/crates/oxide_vm/tests/builtins_regexp_tests.rs b/crates/oxide_vm/tests/builtins_regexp_tests.rs
index bb3c026c..7369912c 100644
--- a/crates/oxide_vm/tests/builtins_regexp_tests.rs
+++ b/crates/oxide_vm/tests/builtins_regexp_tests.rs
@@ -1188,3 +1188,24 @@ fn regexp_v_flag_zero_width_surrogate_pair_match_returns() {
     let result = eval(&mut vm, "var m = '𠮷a'.match(/(?:)/g); m.length + ':' + m.join('|')").unwrap();
     assert_eq!(to_str(&vm, result), "4:|||");
 }
+
+// --- RegExp.prototype.flags getter ---
+
+#[test]
+fn flags_getter_plain_object_reads_accessor_props() {
+    // 无 [[RegExp]] 槽的对象 this：按规范序读 8 个旗访问器（hasIndices/
+    // global/ignoreCase/multiline/dotAll/unicode/unicodeSets/sticky）并以
+    // ToBoolean 判位组串；prototype 本身读得全 falsy 返空串。
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "var get = Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get; get.call({ global: 'string', ignoreCase: 1 })").unwrap();
+    assert_eq!(to_str(&vm, result), "gi");
+    let result = eval(
+        &mut vm,
+        "var get = Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get; get.call(RegExp.prototype)",
+    )
+    .unwrap();
+    assert_eq!(to_str(&vm, result), "");
+    // 非对象 this 抛 TypeError。
+    let result = eval(&mut vm, "var get = Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get; try { get.call(4); 'no-throw' } catch (e) { e instanceof TypeError }").unwrap();
+    assert!(result.as_bool());
+}