Bug 1283710 - Part 5: Rename message to toStringResult if it is the result of toString. r=bholley,jwalden,froydnj

dom/base/ScriptSettings.cpp

@@ -533,7 +533,7 @@ WarningOnlyErrorReporter(JSContext* aCx, JSErrorReport* aRep)
     workers::WorkerPrivate* worker = workers::GetWorkerPrivateFromContext(aCx);
     MOZ_ASSERT(worker);
 
-    worker->ReportError(aCx, nullptr, aRep);
+    worker->ReportError(aCx, JS::ConstUTF8CharsZ(), aRep);
     return;
   }
 
@@ -585,7 +585,7 @@ AutoJSAPI::ReportException()
         win = xpc::AddonWindowOrNull(errorGlobal);
       }
       nsPIDOMWindowInner* inner = win ? win->AsInner() : nullptr;
-      xpcReport->Init(jsReport.report(), jsReport.message().c_str(),
+      xpcReport->Init(jsReport.report(), jsReport.toStringResult().c_str(),
                       nsContentUtils::IsCallerChrome(),
                       inner ? inner->WindowID() : 0);
       if (inner && jsReport.report()->errorNumber != JSMSG_OUT_OF_MEMORY) {
@@ -609,7 +609,7 @@ AutoJSAPI::ReportException()
       // to get hold of it.  After we invoke ReportError, clear the exception on
       // cx(), just in case ReportError didn't.
       JS_SetPendingException(cx(), exn);
-      worker->ReportError(cx(), jsReport.message().c_str(), jsReport.report());
+      worker->ReportError(cx(), jsReport.toStringResult(), jsReport.report());
       ClearException();
     }
   } else {

dom/promise/Promise.cpp

@@ -1022,7 +1022,7 @@ Promise::ReportRejectedPromise(JSContext* aCx, JS::HandleObject aPromise)
   bool isChrome = isMainThread ? nsContentUtils::IsSystemPrincipal(nsContentUtils::ObjectPrincipal(aPromise))
                                : GetCurrentThreadWorkerPrivate()->IsChromeWorker();
   nsGlobalWindow* win = isMainThread ? xpc::WindowGlobalOrNull(aPromise) : nullptr;
-  xpcReport->Init(report.report(), report.message().c_str(), isChrome,
+  xpcReport->Init(report.report(), report.toStringResult().c_str(), isChrome,
                   win ? win->AsInner()->WindowID() : 0);
 
   // Now post an event to do the real reporting async
@@ -2645,7 +2645,8 @@ Promise::MaybeReportRejected()
   if (exp) {
     xpcReport->Init(cx, exp, isChrome, windowID);
   } else {
-    xpcReport->Init(report.report(), report.message(), isChrome, windowID);
+    xpcReport->Init(report.report(), report.toStringResult(),
+                    isChrome, windowID);
   }
 
   // Now post an event to do the real reporting async

dom/workers/ScriptLoader.cpp

@@ -2094,7 +2094,7 @@ ScriptExecutorRunnable::LogExceptionToConsole(JSContext* aCx,
   }
 
   RefPtr<xpc::ErrorReport> xpcReport = new xpc::ErrorReport();
-  xpcReport->Init(report.report(), report.message().c_str(),
+  xpcReport->Init(report.report(), report.toStringResult().c_str(),
                   aWorkerPrivate->IsChromeWorker(), aWorkerPrivate->WindowID());
 
   RefPtr<AsyncErrorReporter> r = new AsyncErrorReporter(xpcReport);

dom/workers/ServiceWorkerEvents.cpp

@@ -426,7 +426,7 @@ ExtractErrorValues(JSContext* aCx, JS::Handle<JS::Value> aValue,
       // this report anywhere.
       RefPtr<xpc::ErrorReport> report = new xpc::ErrorReport();
       report->Init(err,
-                   "<unknown>", // fallback message
+                   "<unknown>", // toString result
                    false,       // chrome
                    0);          // window ID
 

dom/workers/WorkerPrivate.cpp

@@ -86,6 +86,7 @@
 #include "nsProxyRelease.h"
 #include "nsQueryObject.h"
 #include "nsSandboxFlags.h"
+#include "nsUTF8Utils.h"
 #include "prthread.h"
 #include "xpcpublic.h"
 
@@ -5811,7 +5812,7 @@ WorkerPrivate::NotifyInternal(JSContext* aCx, Status aStatus)
 }
 
 void
-WorkerPrivate::ReportError(JSContext* aCx, const char* aFallbackMessage,
+WorkerPrivate::ReportError(JSContext* aCx, JS::ConstUTF8CharsZ aToStringResult,
                            JSErrorReport* aReport)
 {
   AssertIsOnWorkerThread();
@@ -5855,13 +5856,19 @@ WorkerPrivate::ReportError(JSContext* aCx, const char* aFallbackMessage,
     flags = nsIScriptError::errorFlag | nsIScriptError::exceptionFlag;
   }
 
-  if (message.IsEmpty() && aFallbackMessage) {
-    nsDependentCString fallbackMessage(aFallbackMessage);
-    if (!AppendUTF8toUTF16(fallbackMessage, message, mozilla::fallible)) {
+  if (message.IsEmpty() && aToStringResult) {
+    nsDependentCString toStringResult(aToStringResult.c_str());
+    if (!AppendUTF8toUTF16(toStringResult, message, mozilla::fallible)) {
       // Try again, with only a 1 KB string. Do this infallibly this time.
       // If the user doesn't have 1 KB to spare we're done anyways.
-      nsDependentCString truncatedFallbackMessage(aFallbackMessage, 1024);
-      AppendUTF8toUTF16(truncatedFallbackMessage, message);
+      uint32_t index = std::min(uint32_t(1024), toStringResult.Length());
+
+      // Drop the last code point that may be cropped.
+      index = RewindToPriorUTF8Codepoint(toStringResult.BeginReading(), index);
+
+      nsDependentCString truncatedToStringResult(aToStringResult.c_str(),
+                                                 index);
+      AppendUTF8toUTF16(truncatedToStringResult, message);
     }
   }
 

dom/workers/WorkerPrivate.h

@@ -9,6 +9,7 @@
 
 #include "Workers.h"
 
+#include "js/CharacterEncoding.h"
 #include "nsIContentPolicy.h"
 #include "nsIContentSecurityPolicy.h"
 #include "nsILoadGroup.h"
@@ -1164,7 +1165,8 @@ public:
   NotifyInternal(JSContext* aCx, Status aStatus);
 
   void
-  ReportError(JSContext* aCx, const char* aMessage, JSErrorReport* aReport);
+  ReportError(JSContext* aCx, JS::ConstUTF8CharsZ aToStringResult,
+              JSErrorReport* aReport);
 
   static void
   ReportErrorToConsole(const char* aMessage);

js/src/jsapi-tests/testParseJSON.cpp

@@ -307,7 +307,7 @@ Error(JSContext* cx, const char (&input)[N], uint32_t expectedLine,
     CHECK(report.report()->errorNumber == JSMSG_JSON_BAD_PARSE);
 
     const char* lineAndColumnASCII = JS_smprintf("line %d column %d", expectedLine, expectedColumn);
-    CHECK(strstr(report.message().c_str(), lineAndColumnASCII) != nullptr);
+    CHECK(strstr(report.toStringResult().c_str(), lineAndColumnASCII) != nullptr);
     js_free((void*)lineAndColumnASCII);
 
     /* We do not execute JS, so there should be no exception thrown. */

js/src/jsapi-tests/testUncaughtSymbol.cpp

@@ -41,11 +41,11 @@ GetSymbolExceptionType(JSContext* cx)
     js::ErrorReport report(cx);
     MOZ_RELEASE_ASSERT(report.init(cx, exn, js::ErrorReport::WithSideEffects));
 
-    if (strcmp(report.message().c_str(), "uncaught exception: Symbol(Symbol.iterator)") == 0)
+    if (strcmp(report.toStringResult().c_str(), "uncaught exception: Symbol(Symbol.iterator)") == 0)
         return SYMBOL_ITERATOR;
-    if (strcmp(report.message().c_str(), "uncaught exception: Symbol(foo)") == 0)
+    if (strcmp(report.toStringResult().c_str(), "uncaught exception: Symbol(foo)") == 0)
         return SYMBOL_FOO;
-    if (strcmp(report.message().c_str(), "uncaught exception: Symbol()") == 0)
+    if (strcmp(report.toStringResult().c_str(), "uncaught exception: Symbol()") == 0)
         return SYMBOL_EMPTY;
     MOZ_CRASH("Unexpected symbol");
 }

js/src/jscntxt.cpp

@@ -382,8 +382,8 @@ js::ReportUsageErrorASCII(JSContext* cx, HandleObject callee, const char* msg)
 }
 
 bool
-js::PrintError(JSContext* cx, FILE* file, const char* message, JSErrorReport* report,
-               bool reportWarnings)
+js::PrintError(JSContext* cx, FILE* file, JS::ConstUTF8CharsZ toStringResult,
+               JSErrorReport* report, bool reportWarnings)
 {
     MOZ_ASSERT(report);
 
@@ -407,8 +407,7 @@ js::PrintError(JSContext* cx, FILE* file, const char* message, JSErrorReport* re
         JS_free(cx, tmp);
     }
 
-    if (!message)
-        message = report->message().c_str();
+    const char* message = toStringResult ? toStringResult.c_str() : report->message().c_str();
 
     /* embedded newlines -- argh! */
     const char* ctmp;

js/src/jscntxt.h

@@ -631,8 +631,8 @@ ReportUsageErrorASCII(JSContext* cx, HandleObject callee, const char* msg);
  * Returns false otherwise.
  */
 extern bool
-PrintError(JSContext* cx, FILE* file, const char* message, JSErrorReport* report,
-           bool reportWarnings);
+PrintError(JSContext* cx, FILE* file, JS::ConstUTF8CharsZ toStringResult,
+           JSErrorReport* report, bool reportWarnings);
 
 /*
  * Send a JSErrorReport to the warningReporter callback.

js/src/jsexn.cpp

@@ -28,6 +28,7 @@
 #include "jswrapper.h"
 
 #include "gc/Marking.h"
+#include "js/CharacterEncoding.h"
 #include "vm/ErrorObject.h"
 #include "vm/GlobalObject.h"
 #include "vm/SavedStacks.h"
@@ -512,7 +513,7 @@ js::ErrorToException(JSContext* cx, JSErrorReport* reportp,
     // we cannot construct the Error constructor without self-hosted code. Just
     // print the error to stderr to help debugging.
     if (cx->runtime()->isSelfHostingCompartment(cx->compartment())) {
-        PrintError(cx, stderr, nullptr, reportp, true);
+        PrintError(cx, stderr, JS::ConstUTF8CharsZ(), reportp, true);
         return;
     }
 
@@ -852,7 +853,7 @@ ErrorReport::init(JSContext* cx, HandleValue exn,
 
     const char* utf8Message = nullptr;
     if (str)
-        utf8Message = bytesStorage.encodeUtf8(cx, str);
+        utf8Message = toStringResultBytesStorage.encodeUtf8(cx, str);
     if (!utf8Message)
         utf8Message = "unknown (can't convert to string)";
 
@@ -870,7 +871,7 @@ ErrorReport::init(JSContext* cx, HandleValue exn,
             return false;
         }
     } else {
-        message_ = JS::ConstUTF8CharsZ(utf8Message, strlen(utf8Message));
+        toStringResult_ = JS::ConstUTF8CharsZ(utf8Message, strlen(utf8Message));
         /* Flag the error as an exception. */
         reportp->flags |= JSREPORT_EXCEPTION;
     }
@@ -914,7 +915,7 @@ ErrorReport::populateUncaughtExceptionReportUTF8VA(JSContext* cx, va_list ap)
         return false;
     }
 
-    message_ = ownedReport.message();
+    toStringResult_ = ownedReport.message();
     reportp = &ownedReport;
     return true;
 }

js/src/jsfriendapi.h

@@ -1452,9 +1452,9 @@ struct MOZ_STACK_CLASS JS_FRIEND_API(ErrorReport)
         return reportp;
     }
 
-    const JS::ConstUTF8CharsZ message()
+    const JS::ConstUTF8CharsZ toStringResult()
     {
-        return message_;
+        return toStringResult_;
     }
 
   private:
@@ -1473,9 +1473,6 @@ struct MOZ_STACK_CLASS JS_FRIEND_API(ErrorReport)
     // We may have a provided JSErrorReport, so need a way to represent that.
     JSErrorReport* reportp;
 
-    // And we may have a message.
-    JS::ConstUTF8CharsZ message_;
-
     // Or we may need to synthesize a JSErrorReport one of our own.
     JSErrorReport ownedReport;
 
@@ -1489,11 +1486,14 @@ struct MOZ_STACK_CLASS JS_FRIEND_API(ErrorReport)
     // And we need to root our exception value.
     JS::RootedObject exnObject;
 
-    // And possibly some byte storage for our message_.
-    JSAutoByteString bytesStorage;
-
     // And for our filename.
     JSAutoByteString filename;
+
+    // We may have a result of error.toString().
+    // FIXME: We should not call error.toString(), since it could have side
+    //        effect (see bug 633623).
+    JS::ConstUTF8CharsZ toStringResult_;
+    JSAutoByteString toStringResultBytesStorage;
 };
 
 /* Implemented in vm/StructuredClone.cpp. */

js/src/shell/js.cpp

@@ -6403,7 +6403,7 @@ js::shell::AutoReportException::~AutoReportException()
     MOZ_ASSERT(!JSREPORT_IS_WARNING(report.report()->flags));
 
     FILE* fp = ErrorFilePointer();
-    PrintError(cx, fp, report.message().c_str(), report.report(), reportWarnings);
+    PrintError(cx, fp, report.toStringResult(), report.report(), reportWarnings);
 
     {
         JS::AutoSaveExceptionState savedExc(cx);
@@ -6439,7 +6439,7 @@ js::shell::WarningReporter(JSContext* cx, JSErrorReport* report)
     }
 
     // Print the warning.
-    PrintError(cx, fp, nullptr, report, reportWarnings);
+    PrintError(cx, fp, JS::ConstUTF8CharsZ(), report, reportWarnings);
 }
 
 static bool

js/src/vm/SelfHosting.cpp

@@ -37,6 +37,7 @@
 #include "gc/Policy.h"
 #include "jit/AtomicOperations.h"
 #include "jit/InlinableNatives.h"
+#include "js/CharacterEncoding.h"
 #include "js/Date.h"
 #include "vm/Compression.h"
 #include "vm/GeneratorObject.h"
@@ -71,7 +72,7 @@ selfHosting_WarningReporter(JSContext* cx, JSErrorReport* report)
     MOZ_ASSERT(report);
     MOZ_ASSERT(JSREPORT_IS_WARNING(report->flags));
 
-    PrintError(cx, stderr, nullptr, report, true);
+    PrintError(cx, stderr, JS::ConstUTF8CharsZ(), report, true);
 }
 
 static bool
@@ -2682,7 +2683,7 @@ MaybePrintAndClearPendingException(JSContext* cx, FILE* file)
     }
 
     MOZ_ASSERT(!JSREPORT_IS_WARNING(report.report()->flags));
-    PrintError(cx, file, report.message().c_str(), report.report(), true);
+    PrintError(cx, file, report.toStringResult(), report.report(), true);
 }
 
 class MOZ_STACK_CLASS AutoSelfHostingErrorReporter

js/xpconnect/src/XPCConvert.cpp

@@ -1090,11 +1090,11 @@ XPCConvert::JSValToXPCException(MutableHandleValue s,
             // extract the report and build an xpcexception from that
             const JSErrorReport* report;
             if (nullptr != (report = JS_ErrorFromException(cx, obj))) {
-                JSAutoByteString message;
-                JSString* str;
-                if (nullptr != (str = ToString(cx, s)))
-                    message.encodeLatin1(cx, str);
-                return JSErrorToXPCException(message.ptr(), ifaceName,
+                JSAutoByteString toStringResult;
+                RootedString str(cx, ToString(cx, s));
+                if (str)
+                    toStringResult.encodeUtf8(cx, str);
+                return JSErrorToXPCException(toStringResult.ptr(), ifaceName,
                                              methodName, report, exceptn);
             }
 
@@ -1191,7 +1191,7 @@ XPCConvert::JSValToXPCException(MutableHandleValue s,
 
 // static
 nsresult
-XPCConvert::JSErrorToXPCException(const char* message,
+XPCConvert::JSErrorToXPCException(const char* toStringResult,
                                   const char* ifaceName,
                                   const char* methodName,
                                   const JSErrorReport* report,
@@ -1204,8 +1204,8 @@ XPCConvert::JSErrorToXPCException(const char* message,
         nsAutoString bestMessage;
         if (report && report->message()) {
             CopyUTF8toUTF16(report->message().c_str(), bestMessage);
-        } else if (message) {
-            CopyASCIItoUTF16(message, bestMessage);
+        } else if (toStringResult) {
+            CopyUTF8toUTF16(toStringResult, bestMessage);
         } else {
             bestMessage.AssignLiteral("JavaScript Error");
         }

js/xpconnect/src/nsXPConnect.cpp

@@ -169,7 +169,7 @@ nsXPConnect::IsISupportsDescendant(nsIInterfaceInfo* info)
 }
 
 void
-xpc::ErrorReport::Init(JSErrorReport* aReport, const char* aFallbackMessage,
+xpc::ErrorReport::Init(JSErrorReport* aReport, const char* aToStringResult,
                        bool aIsChrome, uint64_t aWindowID)
 {
     mCategory = aIsChrome ? NS_LITERAL_CSTRING("chrome javascript")
@@ -177,8 +177,8 @@ xpc::ErrorReport::Init(JSErrorReport* aReport, const char* aFallbackMessage,
     mWindowID = aWindowID;
 
     ErrorReportToMessageString(aReport, mErrorMsg);
-    if (mErrorMsg.IsEmpty() && aFallbackMessage) {
-        mErrorMsg.AssignWithConversion(aFallbackMessage);
+    if (mErrorMsg.IsEmpty() && aToStringResult) {
+        AppendUTF8toUTF16(aToStringResult, mErrorMsg);
     }
 
     if (!aReport->filename) {

js/xpconnect/src/xpcprivate.h

@@ -2376,7 +2376,7 @@ public:
                                         const char* methodName,
                                         nsIException** exception);
 
-    static nsresult JSErrorToXPCException(const char* message,
+    static nsresult JSErrorToXPCException(const char* toStringResult,
                                           const char* ifaceName,
                                           const char* methodName,
                                           const JSErrorReport* report,

js/xpconnect/src/xpcpublic.h

@@ -516,7 +516,7 @@ class ErrorReport {
                   , mIsMuted(false)
     {}
 
-    void Init(JSErrorReport* aReport, const char* aFallbackMessage,
+    void Init(JSErrorReport* aReport, const char* aToStringResult,
               bool aIsChrome, uint64_t aWindowID);
     void Init(JSContext* aCx, mozilla::dom::Exception* aException,
               bool aIsChrome, uint64_t aWindowID);

xpcom/string/nsUTF8Utils.h

@@ -13,6 +13,7 @@
 #include "nscore.h"
 #include "mozilla/Assertions.h"
 #include "mozilla/SSE.h"
+#include "mozilla/TypeTraits.h"
 
 #include "nsCharTraits.h"
 
@@ -722,4 +723,20 @@ private:
 };
 #endif // MOZILLA_INTERNAL_API
 
+
+template<typename Char, typename UnsignedT>
+inline UnsignedT
+RewindToPriorUTF8Codepoint(const Char* utf8Chars, UnsignedT index)
+{
+  static_assert(mozilla::IsSame<Char, char>::value ||
+                mozilla::IsSame<Char, unsigned char>::value ||
+                mozilla::IsSame<Char, signed char>::value,
+                "UTF-8 data must be in 8-bit units");
+  static_assert(mozilla::IsUnsigned<UnsignedT>::value, "index type must be unsigned");
+  while (index > 0 && (utf8Chars[index] & 0xC0) == 0x80)
+    --index;
+
+  return index;
+}
+
 #endif /* !defined(nsUTF8Utils_h_) */