[chrome_elf] Big ELF cleanup. Part 1.

chrome_elf/hook_util/test/hook_util_test.cc

+// Copyright 2016 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 <windows.h>
+
+#include "chrome_elf/hook_util/hook_util.h"
+// Compile in this test DLL, so that it's in the IAT.
+#include "chrome_elf/hook_util/test/hook_util_test_dll.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+// IATHook test constants.
+const char kIATTestDllName[] = "hook_util_test_dll.dll";
+const char kIATExportedApiFunction[] = "ExportedApi";
+
+// IATHook function, which does nothing.
+void IATHookedExportedApi() {
+  return;
+}
+
+class HookTest : public testing::Test {
+ protected:
+  HookTest() {}
+};
+
+//------------------------------------------------------------------------------
+// IATHook tests
+//------------------------------------------------------------------------------
+
+TEST_F(HookTest, IATHook) {

[robertshield, 2016/08/10 20:14:48]

Can you test that double Hook()ing fails as expected (possibly by using
EXPECT_THROW in debug mode?).

[penny, 2016/08/13 19:22:15]

So I'm not exactly sure what you meant here... but I've added two more tests:
1) Trying to hook twice from the same IATHook object fails.
2) Added a check at the bottom that tests if someone else hooks the same IAT
entry (over top of the first hook).  We should leave it alone on Unhook.

Let me know if you meant something that these two don't test!

+  elf_hook::IATHook iat_hook;
+
+  // Sanity test with no hook.
+  ASSERT_EQ(0, ExportedApiCallCount());
+  ExportedApi();
+  ExportedApi();
+  ASSERT_EQ(2, ExportedApiCallCount());
+
+  // Apply IAT hook.
+  ASSERT_EQ(NO_ERROR,
+            iat_hook.Hook(::GetModuleHandle(nullptr), kIATTestDllName,
+                          kIATExportedApiFunction, IATHookedExportedApi));
+
+  // Call count should not change with hook.
+  ExportedApi();
+  ExportedApi();
+  ExportedApi();
+  EXPECT_EQ(2, ExportedApiCallCount());
+
+  // Remove hook.
+  EXPECT_EQ(NO_ERROR, iat_hook.Unhook());
+
+  // Sanity test things are back to normal.
+  ExportedApi();
+  EXPECT_EQ(3, ExportedApiCallCount());
+
+  // Double unhook should fail.
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, iat_hook.Unhook());
+
+  // Try hooking a non-existent function.
+  EXPECT_EQ(ERROR_PROC_NOT_FOUND,
+            iat_hook.Hook(::GetModuleHandle(nullptr), kIATTestDllName,
+                          "FooBarred", IATHookedExportedApi));
+}
+
+}  // namespace