# HG changeset patch
# Parent af4f2eea4e27d92decb28b8205884219a0a38cd7
# User ziyunfei <446240525@qq.com>
Bug 1108467 - Implement RegExp.prototype.flags. r=till

diff --git a/js/src/builtin/RegExp.cpp b/js/src/builtin/RegExp.cpp
--- a/js/src/builtin/RegExp.cpp
+++ b/js/src/builtin/RegExp.cpp
@@ -366,16 +366,82 @@ regexp_toString_impl(JSContext *cx, Call
 
 static bool
 regexp_toString(JSContext *cx, unsigned argc, Value *vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsRegExp, regexp_toString_impl>(cx, args);
 }
 
+/* ES6 draft rev29 21.2.5.3 RegExp.prototype.flags */
+bool
+regexp_flags(JSContext *cx, unsigned argc, JS::Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /* Steps 1-2. */
+    if (!args.thisv().isObject()) {
+        char *bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, args.thisv(), NullPtr());
+        if (!bytes)
+            return false;
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_UNEXPECTED_TYPE,
+                             bytes, "not an object");
+        js_free(bytes);
+        return false;
+    }
+    RootedObject thisObj(cx, &args.thisv().toObject());
+
+    /* Step 3. */
+    StringBuffer sb(cx);
+
+    /* Steps 4-6. */
+    RootedValue global(cx);
+    if (!JSObject::getProperty(cx, thisObj, thisObj, cx->names().global, &global))
+        return false;
+    if (ToBoolean(global) && !sb.append('g'))
+        return false;
+
+    /* Steps 7-9. */
+    RootedValue ignoreCase(cx);
+    if (!JSObject::getProperty(cx, thisObj, thisObj, cx->names().ignoreCase, &ignoreCase))
+        return false;
+    if (ToBoolean(ignoreCase) && !sb.append('i'))
+        return false;
+
+    /* Steps 10-12. */
+    RootedValue multiline(cx);
+    if (!JSObject::getProperty(cx, thisObj, thisObj, cx->names().multiline, &multiline))
+        return false;
+    if (ToBoolean(multiline) && !sb.append('m'))
+        return false;
+
+    /* Steps 13-15. */
+    RootedValue sticky(cx);
+    if (!JSObject::getProperty(cx, thisObj, thisObj, cx->names().sticky, &sticky))
+        return false;
+    if (ToBoolean(sticky) && !sb.append('y'))
+        return false;
+
+    /* Steps 16-18. */
+    RootedValue unicode(cx);
+    if (!JSObject::getProperty(cx, thisObj, thisObj, cx->names().unicode, &unicode))
+        return false;
+    if (ToBoolean(unicode) && !sb.append('u'))
+        return false;
+
+    /* Step 19. */
+    args.rval().setString(sb.finishString());
+    return true;
+}
+
+static const JSPropertySpec regexp_properties[] = {
+    JS_PSG("flags", regexp_flags, 0),
+    JS_PS_END
+};
+
 static const JSFunctionSpec regexp_methods[] = {
 #if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,  regexp_toString,    0,0),
 #endif
     JS_FN(js_toString_str,  regexp_toString,    0,0),
     JS_FN("compile",        regexp_compile,     2,0),
     JS_FN("exec",           regexp_exec,        1,0),
     JS_FN("test",           regexp_test,        1,0),
@@ -512,17 +578,17 @@ js_InitRegExpClass(JSContext *cx, Handle
         return nullptr;
     proto->NativeObject::setPrivate(nullptr);
 
     HandlePropertyName empty = cx->names().empty;
     RegExpObjectBuilder builder(cx, proto);
     if (!builder.build(empty, RegExpFlag(0)))
         return nullptr;
 
-    if (!DefinePropertiesAndFunctions(cx, proto, nullptr, regexp_methods))
+    if (!DefinePropertiesAndFunctions(cx, proto, regexp_properties, regexp_methods))
         return nullptr;
 
     RootedFunction ctor(cx);
     ctor = global->createConstructor(cx, regexp_construct, cx->names().RegExp, 2);
     if (!ctor)
         return nullptr;
 
     if (!LinkConstructorAndPrototype(cx, ctor, proto))
diff --git a/js/src/builtin/RegExp.h b/js/src/builtin/RegExp.h
--- a/js/src/builtin/RegExp.h
+++ b/js/src/builtin/RegExp.h
@@ -7,16 +7,19 @@
 #ifndef builtin_RegExp_h
 #define builtin_RegExp_h
 
 #include "vm/RegExpObject.h"
 
 JSObject *
 js_InitRegExpClass(JSContext *cx, js::HandleObject obj);
 
+bool
+regexp_flags(JSContext *cx, unsigned argc, JS::Value *vp);
+
 /*
  * The following builtin natives are extern'd for pointer comparison in
  * other parts of the engine.
  */
 
 namespace js {
 
 // Whether RegExp statics should be updated with the input and results of a
diff --git a/js/src/tests/ecma_6/RegExp/browser.js b/js/src/tests/ecma_6/RegExp/browser.js
new file mode 100644
diff --git a/js/src/tests/ecma_6/RegExp/flags.js b/js/src/tests/ecma_6/RegExp/flags.js
new file mode 100644
--- /dev/null
+++ b/js/src/tests/ecma_6/RegExp/flags.js
@@ -0,0 +1,28 @@
+var BUGNUMBER = 1108467;
+var summary = "Implement RegExp.prototype.flags";
+
+print(BUGNUMBER + ": " + summary);
+
+assertEq(RegExp.prototype.flags, "");
+assertEq(/foo/iymg.flags, "gimy");
+assertEq(RegExp("").flags, "");
+assertEq(RegExp("", "mygi").flags, "gimy");
+assertThrowsInstanceOf(() => RegExp("", "mygui").flags, SyntaxError);
+// When the /u flag is supported, uncomment the line below and remove the line above
+// assertEq(RegExp("", "mygui").flags, "gimyu");
+assertEq(genericFlags({}), "");
+assertEq(genericFlags({ignoreCase: true}), "i");
+assertEq(genericFlags({sticky:1, unicode:1, global: 0}), "yu");
+assertEq(genericFlags({__proto__: {multiline: true}}), "m");
+assertEq(genericFlags(new Proxy({}, {get(){return true}})), "gimyu");
+
+assertThrowsInstanceOf(() => genericFlags(), TypeError);
+assertThrowsInstanceOf(() => genericFlags(1), TypeError);
+assertThrowsInstanceOf(() => genericFlags(""), TypeError);
+
+function genericFlags(obj) {
+    return Object.getOwnPropertyDescriptor(RegExp.prototype,"flags").get.call(obj);
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);
diff --git a/js/src/tests/ecma_6/RegExp/shell.js b/js/src/tests/ecma_6/RegExp/shell.js
new file mode 100644
diff --git a/js/src/vm/CommonPropertyNames.h b/js/src/vm/CommonPropertyNames.h
--- a/js/src/vm/CommonPropertyNames.h
+++ b/js/src/vm/CommonPropertyNames.h
@@ -191,16 +191,17 @@
     macro(toJSON, toJSON, "toJSON") \
     macro(toLocaleString, toLocaleString, "toLocaleString") \
     macro(toSource, toSource, "toSource") \
     macro(toString, toString, "toString") \
     macro(toUTCString, toUTCString, "toUTCString") \
     macro(true, true_, "true") \
     macro(unescape, unescape, "unescape") \
     macro(uneval, uneval, "uneval") \
+    macro(unicode, unicode, "unicode") \
     macro(uninitialized, uninitialized, "uninitialized") \
     macro(uint8, uint8, "uint8") \
     macro(uint8Clamped, uint8Clamped, "uint8Clamped") \
     macro(uint16, uint16, "uint16") \
     macro(uint32, uint32, "uint32") \
     macro(unsized, unsized, "unsized") \
     macro(unwatch, unwatch, "unwatch") \
     macro(url, url, "url") \