Don't call exit() after __debugbreak() on release builds.

This CL optimizes code for debugging as opposed to for someone who attaches a
debugger and goes beyond a CHECK without realizing it. Debugging a release
build is already hard, especially on 64-bit builds.

BUG=408820
R=wfh@chromium.org

Review URL: https://codereview.chromium.org/759283005

Cr-Commit-Position: refs/heads/master@{#306871}

2 files changed, 44 insertions, 3 deletions

diff --git a/base/debug/debugger_unittest.cc b/base/debug/debugger_unittest.cc
new file mode 100644
index 0000000..0a5a039
--- /dev/null
+++ b/base/debug/debugger_unittest.cc
@@ -0,0 +1,43 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/debug/debugger.h"
+
+#include "build/build_config.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(OS_ANDROID)
+void CrashWithBreakDebugger() {
+  base::debug::SetSuppressDebugUI(false);
+  base::debug::BreakDebugger();
+
+#if defined(OS_WIN)
+  // This should not be executed.
+  _exit(125);
+#endif
+}
+#endif  // defined(GTEST_HAS_DEATH_TEST)
+
+}  // namespace
+
+// Death tests misbehave on Android.
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(OS_ANDROID)
+
+TEST(Debugger, CrashAtBreakpoint) {
+  EXPECT_DEATH(CrashWithBreakDebugger(), "");
+}
+
+#if defined(OS_WIN)
+TEST(Debugger, DoesntExecuteBeyondBreakpoint) {
+  EXPECT_EXIT(CrashWithBreakDebugger(),
+              ::testing::ExitedWithCode(0x80000003), "");
+}
+#endif  // defined(OS_WIN)
+
+#else  // defined(GTEST_HAS_DEATH_TEST) && !defined(OS_ANDROID)
+TEST(Debugger, NoTest) {
+}
+#endif  // defined(GTEST_HAS_DEATH_TEST) && !defined(OS_ANDROID)
diff --git a/base/debug/debugger_win.cc b/base/debug/debugger_win.cc
index ccc9c16..a1d86e4 100644
--- a/base/debug/debugger_win.cc
+++ b/base/debug/debugger_win.cc
@@ -17,10 +17,8 @@ bool BeingDebugged() {
 void BreakDebugger() {
   if (IsDebugUISuppressed())
     _exit(1);
+
   __debugbreak();
-#if defined(NDEBUG)
-  _exit(1);
-#endif
 }
 
 }  // namespace debug