Bug 31720

Some exception specifications for DOM attribute accessors seem to result in incorrect generated Objective-C++ code. I have seen two cases, and suspect they are related, so I have bundled them into a single report. These cases are both based on an attribute named 'cookie', originally specified in Document.idl as follows: attribute [ConvertNullToNullString] DOMString cookie; The observed output concerns the generated DOMDocument.mm. I verified these results on r51076, host Mac OS X 10.6.2. Nov 20, 2009. CASE 1 ====== The first case was encountered when trying to make the getter raise an exception, but not the setter. I specified this in Document.idl as follows: attribute [ConvertNullToNullString] DOMString cookie getter raises (DOMException); I would expect the generated DOMDocument.mm to handle exceptions in the getter, but not the setter. However, it seems to expect an exception to be raised by the setter as well: expected: - (void)setCookie:(NSString *)newCookie { IMPL->setCookie(newCookie); } actual: - (void)setCookie:(NSString *)newCookie { WebCore::ExceptionCode ec = 0; IMPL->setCookie(newCookie, ec); WebCore::raiseOnDOMError(ec); } A work-around appears to be to use a 'raises' clause with an empty exception list: attribute [ConvertNullToNullString] DOMString cookie getter raises (DOMException), setter raises (/*DOMException*/); CASE 2 ====== The second case was encountered when trying to make both setter and getter raise exceptions. I believe this could be specified as follows: attribute [ConvertNullToNullString] DOMString cookie raises (DOMException); This also resulted in incorrect generated code (Document.cpp raises errors, but DOMDocument.mm does not expect them): expected: - (NSString *)cookie { WebCore::ExceptionCode ec = 0; NSString *result = IMPL->cookie(ec); WebCore::raiseOnDOMError(ec); return result; } - (void)setCookie:(NSString *)newCookie { WebCore::ExceptionCode ec = 0; IMPL->setCookie(newCookie, ec); WebCore::raiseOnDOMError(ec); } actual: - (NSString *)cookie { return IMPL->cookie(); } - (void)setCookie:(NSString *)newCookie { IMPL->setCookie(newCookie); } A work-around appears to be separate 'raises' clauses for getter and setter: attribute [ConvertNullToNullString] DOMString cookie getter raises (DOMException), setter raises (DOMException);