Changeset 206476 in webkit

Timestamp:

Sep 27, 2016 5:26:15 PM (8 years ago)

Author:

mark.lam@apple.com

Message:

createError() and JSObject::calculatedClassName() should not throw any exceptions.
​https://bugs.webkit.org/show_bug.cgi?id=162637

Reviewed by Geoffrey Garen.

• runtime/ExceptionHelpers.cpp:

(JSC::createError):

• assert that errorDescriptionForValue() did not throw an exception.

• runtime/JSObject.cpp:

(JSC::JSObject::calculatedClassName):

• the code already ensures that we always return a non-null String. Just need to make sure that it catches its own exceptions.

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/ExceptionHelpers.cpp (modified) (1 diff)
• runtime/JSObject.cpp (modified) (3 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2016-09-27  Mark Lam  <mark.lam@apple.com>
+
+        createError() and JSObject::calculatedClassName() should not throw any exceptions.
+        https://bugs.webkit.org/show_bug.cgi?id=162637
+
+        Reviewed by Geoffrey Garen.
+
+        * runtime/ExceptionHelpers.cpp:
+        (JSC::createError):
+        - assert that errorDescriptionForValue() did not throw an exception.
+
+        * runtime/JSObject.cpp:
+        (JSC::JSObject::calculatedClassName):
+        - the code already ensures that we always return a non-null String.  Just need to
+          make sure that it catches its own exceptions.
+
 2016-09-27  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/runtime/ExceptionHelpers.cpp

@@ -237 +237 @@
 JSObject* createError(ExecState* exec, JSValue value, const String& message, ErrorInstance::SourceAppender appender)
 {
+    VM& vm = exec->vm();
+    auto scope = DECLARE_CATCH_SCOPE(vm);
+
     String errorMessage = makeString(errorDescriptionForValue(exec, value)->value(exec), ' ', message);
+    ASSERT_UNUSED(scope, !scope.exception());
     JSObject* exception = createTypeError(exec, errorMessage, appender, runtimeTypeForValue(value));
     ASSERT(exception->isErrorInstance());

trunk/Source/JavaScriptCore/runtime/JSObject.cpp

@@ -231 +231 @@
 {
     String prototypeFunctionName;
-    ExecState* exec = object->globalObject()->globalExec();
+    auto globalObject = object->globalObject();
+    VM& vm = globalObject->vm();
+    auto scope = DECLARE_CATCH_SCOPE(vm);
+
+    ExecState* exec = globalObject->globalExec();
     PropertySlot slot(object->getPrototypeDirect(), PropertySlot::InternalMethodType::VMInquiry);
     PropertyName constructor(exec->propertyNames().constructor);
@@ -240 +244 @@
                 if (JSCell* constructorCell = constructorValue.asCell()) {
                     if (JSObject* ctorObject = constructorCell->getObject()) {
-                        VM& vm = exec->vm();
                         if (JSFunction* constructorFunction = jsDynamicCast<JSFunction*>(ctorObject))
                             prototypeFunctionName = constructorFunction->calculatedDisplayName(vm);
@@ -250 +253 @@
         }
     }
+    ASSERT(!scope.exception() || prototypeFunctionName.isNull());
+    if (UNLIKELY(scope.exception()))
+        scope.clearException();
 
     if (prototypeFunctionName.isNull() || prototypeFunctionName == "Object") {