Re-land r303274: "[CrashRecovery] Use SEH __try instead of VEH when available"

We have to check gCrashRecoveryEnabled before using __try.

In other words, SEH works too well and we ended up recovering from
crashes in implicit module builds that we weren't supposed to. Only
libclang is supposed to enable CrashRecoveryContext to allow implicit
module builds to crash.

llvm-svn: 303279

1 files changed, 83 insertions, 0 deletions

diff --git a/llvm/unittests/Support/CrashRecoveryTest.cpp b/llvm/unittests/Support/CrashRecoveryTest.cpp
new file mode 100644
index 00000000000..dbb0db57679
--- /dev/null
+++ b/llvm/unittests/Support/CrashRecoveryTest.cpp
@@ -0,0 +1,83 @@
+//===- llvm/unittest/Support/CrashRecoveryTest.cpp ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/CrashRecoveryContext.h"
+#include "llvm/Support/Compiler.h"
+#include "gtest/gtest.h"
+
+#ifdef LLVM_ON_WIN32
+#define WIN32_LEAN_AND_MEAN
+#define NOGDI
+#include <windows.h>
+#endif
+
+using namespace llvm;
+using namespace llvm::sys;
+
+static int GlobalInt = 0;
+static void nullDeref() { *(volatile int *)nullptr = 0; }
+static void incrementGlobal() { ++GlobalInt; }
+static void llvmTrap() { LLVM_BUILTIN_TRAP; }
+
+TEST(CrashRecoveryTest, Basic) {
+  llvm::CrashRecoveryContext::Enable();
+  GlobalInt = 0;
+  EXPECT_TRUE(CrashRecoveryContext().RunSafely(incrementGlobal));
+  EXPECT_EQ(1, GlobalInt);
+  EXPECT_FALSE(CrashRecoveryContext().RunSafely(nullDeref));
+  EXPECT_FALSE(CrashRecoveryContext().RunSafely(llvmTrap));
+}
+
+struct IncrementGlobalCleanup : CrashRecoveryContextCleanup {
+  IncrementGlobalCleanup(CrashRecoveryContext *CRC)
+      : CrashRecoveryContextCleanup(CRC) {}
+  virtual void recoverResources() { ++GlobalInt; }
+};
+
+static void noop() {}
+
+TEST(CrashRecoveryTest, Cleanup) {
+  llvm::CrashRecoveryContext::Enable();
+  GlobalInt = 0;
+  {
+    CrashRecoveryContext CRC;
+    CRC.registerCleanup(new IncrementGlobalCleanup(&CRC));
+    EXPECT_TRUE(CRC.RunSafely(noop));
+  } // run cleanups
+  EXPECT_EQ(1, GlobalInt);
+
+  GlobalInt = 0;
+  {
+    CrashRecoveryContext CRC;
+    CRC.registerCleanup(new IncrementGlobalCleanup(&CRC));
+    EXPECT_FALSE(CRC.RunSafely(nullDeref));
+  } // run cleanups
+  EXPECT_EQ(1, GlobalInt);
+}
+
+#ifdef LLVM_ON_WIN32
+static void raiseIt() {
+  RaiseException(123, EXCEPTION_NONCONTINUABLE, 0, NULL);
+}
+
+TEST(CrashRecoveryTest, RaiseException) {
+  llvm::CrashRecoveryContext::Enable();
+  EXPECT_FALSE(CrashRecoveryContext().RunSafely(raiseIt));
+}
+
+static void outputString() {
+  OutputDebugStringA("output for debugger\n");
+}
+
+TEST(CrashRecoveryTest, CallOutputDebugString) {
+  llvm::CrashRecoveryContext::Enable();
+  EXPECT_TRUE(CrashRecoveryContext().RunSafely(outputString));
+}
+
+#endif