Bug 775378 - Trap exception handling calls to __abi_FailFast made by winrt delegate wrapper code. r=ted

toolkit/library/nsDllMain.cpp

@@ -6,6 +6,7 @@
 #include <windows.h>
 #include <delayimp.h>
 #include "nsToolkit.h"
+#include "mozilla/Assertions.h"
 
 #if defined(__GNUC__)
 // If DllMain gets name mangled, it won't be seen.
@@ -51,6 +52,16 @@ BOOL APIENTRY DllMain(
  * Win7. To get around this we generate a dummy vccore lib with the three entry
  * points the initializer needs and load it in place of the real vccorlib. We
  * also have to add vccorlib and the system dlls to the delay load list.
+ *
+ * In addition to setting up dummyvccorlib, we also have additional checks for
+ * for unexpected behavior, specifically:
+ * - trap attempts to load entry points in dummyvccorlib. This is not expected
+ *   to happen in release code. It can happen during development if winrt apis
+ *   are accessed when running on the desktop, or when winrt objects are
+ *   accidentially placed in the global scope.
+ * - trap and handle calls to vccorlib's __abi_FailFast in a breakpad compatible
+ *   way. __abi_FailFast is called by exception handling code generated by the
+ *   compiler for delegate events.
  */
 static bool IsWin8OrHigher()
 {
@@ -71,29 +82,47 @@ static bool IsWin8OrHigher()
 
 const char* kvccorlib = "vccorlib";
 const char* kwinrtprelim = "api-ms-win-core-winrt";
+const char* kfailfast = "?__abi_FailFast";
 
-static bool IsWinRTDLLPresent(PDelayLoadInfo pdli, const char* aLibToken)
+static bool IsWinRTDLLNotPresent(PDelayLoadInfo pdli, const char* aLibToken)
 {
   return (!IsWin8OrHigher() && pdli->szDll &&
           !strnicmp(pdli->szDll, aLibToken, strlen(aLibToken)));
 }
 
+static bool IsWinRTDLLPresent(PDelayLoadInfo pdli, const char* aLibToken)
+{
+  return (IsWin8OrHigher() && pdli->szDll &&
+          !strnicmp(pdli->szDll, aLibToken, strlen(aLibToken)));
+}
+
+void __stdcall __abi_MozFailFast()
+{
+  MOZ_CRASH();
+}
+
 FARPROC WINAPI DelayDllLoadHook(unsigned dliNotify, PDelayLoadInfo pdli)
 {
   if (dliNotify == dliNotePreLoadLibrary) {
-    if (IsWinRTDLLPresent(pdli, kvccorlib)) {
+    if (IsWinRTDLLNotPresent(pdli, kvccorlib)) {
       return (FARPROC)LoadLibraryA("dummyvccorlib.dll");
     }
-    NS_ASSERTION(!IsWinRTDLLPresent(pdli, kwinrtprelim),
+    NS_ASSERTION(!IsWinRTDLLNotPresent(pdli, kwinrtprelim),
       "Attempting to load winrt libs in non-metro environment. "
       "(Winrt variable type placed in global scope?)");
   }
-  if (dliNotify == dliFailGetProc && IsWinRTDLLPresent(pdli, kvccorlib)) {
+  if (dliNotify == dliFailGetProc && IsWinRTDLLNotPresent(pdli, kvccorlib)) {
     NS_WARNING("Attempting to access winrt vccorlib entry point in non-metro environment.");
     NS_WARNING(pdli->szDll);
     NS_WARNING(pdli->dlp.szProcName);
     NS_ABORT();
   }
+  if (dliNotify == dliNotePreGetProcAddress &&
+      IsWinRTDLLPresent(pdli, kvccorlib) &&
+      pdli->dlp.szProcName &&
+      !strnicmp(pdli->dlp.szProcName, kfailfast, strlen(kfailfast))) {
+    return (FARPROC)__abi_MozFailFast;
+  }
   return NULL;
 }