4 files changed, 40 insertions, 1 deletions
diff --git a/js/src/builtin/RegExp.cpp b/js/src/builtin/RegExp.cpp
index 7cf20d23c..b7853d533 100644
--- a/js/src/builtin/RegExp.cpp
+++ b/js/src/builtin/RegExp.cpp
@@ -178,7 +178,7 @@ CheckPatternSyntax(JSContext* cx, HandleAtom pattern, RegExpFlag flags)
     CompileOptions options(cx);
     frontend::TokenStream dummyTokenStream(cx, options, nullptr, 0, nullptr);
     return irregexp::ParsePatternSyntax(dummyTokenStream, cx->tempLifoAlloc(), pattern,
-                                        flags & UnicodeFlag);
+                                        flags & UnicodeFlag, flags & DotAllFlag);
 }
 
 enum RegExpSharedUse {
@@ -664,6 +664,29 @@ js::regexp_multiline(JSContext* cx, unsigned argc, JS::Value* vp)
     return CallNonGenericMethod<IsRegExpInstanceOrPrototype, regexp_multiline_impl>(cx, args);
 }
 
+// ES 2018 dotAll
+MOZ_ALWAYS_INLINE bool
+regexp_dotall_impl(JSContext* cx, const CallArgs& args)
+{
+    MOZ_ASSERT(IsRegExpInstanceOrPrototype(args.thisv()));
+
+    if (!IsRegExpObject(args.thisv())) {
+        args.rval().setUndefined();
+        return true;
+    }
+
+    Rooted<RegExpObject*> reObj(cx, &args.thisv().toObject().as<RegExpObject>());
+    args.rval().setBoolean(reObj->dotall());
+    return true;
+}
+
+bool
+js::regexp_dotall(JSContext* cx, unsigned argc, JS::Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsRegExpInstanceOrPrototype, regexp_dotall_impl>(cx, args);
+}
+
 // ES 2017 draft rev32 21.2.5.10.
 MOZ_ALWAYS_INLINE bool
 regexp_source_impl(JSContext* cx, const CallArgs& args)
@@ -759,6 +782,7 @@ const JSPropertySpec js::regexp_properties[] = {
     JS_PSG("source", regexp_source, 0),
     JS_PSG("sticky", regexp_sticky, 0),
     JS_PSG("unicode", regexp_unicode, 0),
+    JS_PSG("dotall", regexp_dotall, 0),
     JS_PS_END
 };
 
@@ -1642,6 +1666,13 @@ js::RegExpPrototypeOptimizableRaw(JSContext* cx, JSObject* proto)
     if (unicodeGetter != regexp_unicode)
         return false;
 
+    JSNative dotAllGetter;
+    if (!GetOwnNativeGetterPure(cx, proto, NameToId(cx->names().dotall), &dotAllGetter))
+        return false;
+
+    if (dotAllGetter != regexp_dotall)
+        return false;
+
     // Check if @@match, @@search, and exec are own data properties,
     // those values should be tested in selfhosted JS.
     bool has = false;
diff --git a/js/src/builtin/RegExp.h b/js/src/builtin/RegExp.h
index 4e0ff6948..f808f5146 100644
--- a/js/src/builtin/RegExp.h
+++ b/js/src/builtin/RegExp.h
@@ -153,6 +153,8 @@ extern MOZ_MUST_USE bool
 regexp_sticky(JSContext* cx, unsigned argc, JS::Value* vp);
 extern MOZ_MUST_USE bool
 regexp_unicode(JSContext* cx, unsigned argc, JS::Value* vp);
+extern MOZ_MUST_USE bool
+regexp_dotall(JSContext* cx, unsigned argc, JS::Value* vp);
 
 } /* namespace js */
 
diff --git a/js/src/builtin/RegExp.js b/js/src/builtin/RegExp.js
index 0b849292c..1a2276594 100644
--- a/js/src/builtin/RegExp.js
+++ b/js/src/builtin/RegExp.js
@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // ES6 draft rev34 (2015/02/20) 21.2.5.3 get RegExp.prototype.flags
+// Updated for ES2018 /s (dotAll)
 function RegExpFlagsGetter() {
     // Steps 1-2.
     var R = this;
@@ -31,6 +32,10 @@ function RegExpFlagsGetter() {
     // Steps 16-18.
     if (R.sticky)
         result += "y";
+        
+    // ES2018
+    if (R.dotall)
+        result += "s";
 
     // Step 19.
     return result;
diff --git a/js/src/builtin/SelfHostingDefines.h b/js/src/builtin/SelfHostingDefines.h
index d676270a1..6512810ca 100644
--- a/js/src/builtin/SelfHostingDefines.h
+++ b/js/src/builtin/SelfHostingDefines.h
@@ -90,6 +90,7 @@
 #define REGEXP_MULTILINE_FLAG   0x04
 #define REGEXP_STICKY_FLAG      0x08
 #define REGEXP_UNICODE_FLAG     0x10
+#define REGEXP_DOTALL_FLAG      0x20
 
 #define MODULE_OBJECT_ENVIRONMENT_SLOT 2