1 files changed, 59 insertions, 30 deletions

diff --git a/llvm/lib/Support/CrashRecoveryContext.cpp b/llvm/lib/Support/CrashRecoveryContext.cpp
index b9031f52375c..356835609830 100644
--- a/llvm/lib/Support/CrashRecoveryContext.cpp
+++ b/llvm/lib/Support/CrashRecoveryContext.cpp
@@ -14,9 +14,6 @@
 #include "llvm/Support/ThreadLocal.h"
 #include <mutex>
 #include <setjmp.h>
-#ifdef _WIN32
-#include <excpt.h> // for GetExceptionInformation
-#endif
 #if LLVM_ON_UNIX
 #include <sysexits.h> // EX_IOERR
 #endif
@@ -41,11 +38,11 @@ struct CrashRecoveryContextImpl {
   ::jmp_buf JumpBuffer;
   volatile unsigned Failed : 1;
   unsigned SwitchedThread : 1;
+  unsigned ValidJumpBuffer : 1;
 
 public:
-  CrashRecoveryContextImpl(CrashRecoveryContext *CRC) : CRC(CRC),
-                                                        Failed(false),
-                                                        SwitchedThread(false) {
+  CrashRecoveryContextImpl(CrashRecoveryContext *CRC) noexcept
+      : CRC(CRC), Failed(false), SwitchedThread(false), ValidJumpBuffer(false) {
     Next = CurrentContext->get();
     CurrentContext->set(this);
   }
@@ -80,10 +77,13 @@ public:
     CRC->RetCode = RetCode;
 
     // Jump back to the RunSafely we were called under.
-    longjmp(JumpBuffer, 1);
+    if (ValidJumpBuffer)
+      longjmp(JumpBuffer, 1);
+
+    // Otherwise let the caller decide of the outcome of the crash. Currently
+    // this occurs when using SEH on Windows with MSVC or clang-cl.
   }
 };
-
 }
 
 static ManagedStatic<std::mutex> gCrashRecoveryContextMutex;
@@ -175,6 +175,9 @@ CrashRecoveryContext::unregisterCleanup(CrashRecoveryContextCleanup *cleanup) {
 }
 
 #if defined(_MSC_VER)
+
+#include <windows.h> // for GetExceptionInformation
+
 // If _MSC_VER is defined, we must have SEH. Use it if it's available. It's way
 // better than VEH. Vectored exception handling catches all exceptions happening
 // on the thread with installed exception handlers, so it can interfere with
@@ -188,30 +191,45 @@ static void uninstallExceptionOrSignalHandlers() {}
 
 // We need this function because the call to GetExceptionInformation() can only
 // occur inside the __except evaluation block
-static int ExceptionFilter(bool DumpStackAndCleanup,
-                           _EXCEPTION_POINTERS *Except) {
-  if (DumpStackAndCleanup)
-    sys::CleanupOnSignal((uintptr_t)Except);
-  return EXCEPTION_EXECUTE_HANDLER;
-}
+static int ExceptionFilter(_EXCEPTION_POINTERS *Except) {
+  // Lookup the current thread local recovery object.
+  const CrashRecoveryContextImpl *CRCI = CurrentContext->get();
 
-static bool InvokeFunctionCall(function_ref<void()> Fn,
-                               bool DumpStackAndCleanup, int &RetCode) {
-  __try {
-    Fn();
-  } __except (ExceptionFilter(DumpStackAndCleanup, GetExceptionInformation())) {
-    RetCode = GetExceptionCode();
-    return false;
+  if (!CRCI) {
+    // Something has gone horribly wrong, so let's just tell everyone
+    // to keep searching
+    CrashRecoveryContext::Disable();
+    return EXCEPTION_CONTINUE_SEARCH;
   }
-  return true;
+
+  int RetCode = (int)Except->ExceptionRecord->ExceptionCode;
+  if ((RetCode & 0xF0000000) == 0xE0000000)
+    RetCode &= ~0xF0000000; // this crash was generated by sys::Process::Exit
+
+  // Handle the crash
+  const_cast<CrashRecoveryContextImpl *>(CRCI)->HandleCrash(
+      RetCode, reinterpret_cast<uintptr_t>(Except));
+
+  return EXCEPTION_EXECUTE_HANDLER;
 }
 
+#if defined(__clang__) && defined(_M_IX86)
+// Work around PR44697.
+__attribute__((optnone))
+#endif
 bool CrashRecoveryContext::RunSafely(function_ref<void()> Fn) {
   if (!gCrashRecoveryEnabled) {
     Fn();
     return true;
   }
-  return InvokeFunctionCall(Fn, DumpStackAndCleanupOnFailure, RetCode);
+  assert(!Impl && "Crash recovery context already initialized!");
+  Impl = new CrashRecoveryContextImpl(this);
+  __try {
+    Fn();
+  } __except (ExceptionFilter(GetExceptionInformation())) {
+    return false;
+  }
+  return true;
 }
 
 #else // !_MSC_VER
@@ -264,10 +282,13 @@ static LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo)
   // TODO: We can capture the stack backtrace here and store it on the
   // implementation if we so choose.
 
+  int RetCode = (int)ExceptionInfo->ExceptionRecord->ExceptionCode;
+  if ((RetCode & 0xF0000000) == 0xE0000000)
+    RetCode &= ~0xF0000000; // this crash was generated by sys::Process::Exit
+
   // Handle the crash
   const_cast<CrashRecoveryContextImpl *>(CRCI)->HandleCrash(
-      (int)ExceptionInfo->ExceptionRecord->ExceptionCode,
-      reinterpret_cast<uintptr_t>(ExceptionInfo));
+      RetCode, reinterpret_cast<uintptr_t>(ExceptionInfo));
 
   // Note that we don't actually get here because HandleCrash calls
   // longjmp, which means the HandleCrash function never returns.
@@ -388,6 +409,7 @@ bool CrashRecoveryContext::RunSafely(function_ref<void()> Fn) {
     CrashRecoveryContextImpl *CRCI = new CrashRecoveryContextImpl(this);
     Impl = CRCI;
 
+    CRCI->ValidJumpBuffer = true;
     if (setjmp(CRCI->JumpBuffer) != 0) {
       return false;
     }
@@ -399,12 +421,19 @@ bool CrashRecoveryContext::RunSafely(function_ref<void()> Fn) {
 
 #endif // !_MSC_VER
 
-void CrashRecoveryContext::HandleCrash() {
-  CrashRecoveryContextImpl *CRCI = (CrashRecoveryContextImpl *) Impl;
+LLVM_ATTRIBUTE_NORETURN
+void CrashRecoveryContext::HandleExit(int RetCode) {
+#if defined(_WIN32)
+  // SEH and VEH
+  ::RaiseException(0xE0000000 | RetCode, 0, 0, NULL);
+#else
+  // On Unix we don't need to raise an exception, we go directly to
+  // HandleCrash(), then longjmp will unwind the stack for us.
+  CrashRecoveryContextImpl *CRCI = (CrashRecoveryContextImpl *)Impl;
   assert(CRCI && "Crash recovery context never initialized!");
-  // As per convention, -2 indicates a crash or timeout as opposed to failure to
-  // execute (see llvm/include/llvm/Support/Program.h)
-  CRCI->HandleCrash(-2, 0);
+  CRCI->HandleCrash(RetCode, 0 /*no sig num*/);
+#endif
+  llvm_unreachable("Most likely setjmp wasn't called!");
 }
 
 // FIXME: Portability.