Created an ArraySize utility function.

[ Merge of http://go/wvgerrit/82232 ]

The new function `ArraySize` will only work for compile-time fixed-length
arrays, and will provide compiler errors if the provided argument is not an
array.

This will replace the commonly used macro `N_ELEM()` which uses `sizeof()`.

Test: Linux unittest
Bug: 137041745
Change-Id: I0f5c268197a8062a99ccba43c73349e97f66eb02

libwvdrmengine/cdm/core/test/device_files_unittest.cpp

@@ -2,12 +2,15 @@
 // source code may only be used and distributed under the Widevine Master
 // License Agreement.
 
+#include "device_files.h"
+
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
+
 #include <memory>
 #include <string>
 
-#include "device_files.h"
+#include "arraysize.h"
 #include "file_store.h"
 #include "properties.h"
 #include "string_conversions.h"
@@ -2513,8 +2516,7 @@ TEST_F(DeviceFilesTest, UpdateLicenseState) {
   DeviceFiles device_files(&file_system);
   EXPECT_TRUE(device_files.Init(kSecurityLevelL1));
 
-  for (size_t i = 0; i < sizeof(license_update_test_data) / sizeof(LicenseInfo);
+  for (size_t i = 0; i < ArraySize(license_update_test_data); i++) {
-       i++) {
     // Call to Open will return a unique_ptr, freeing this object.
     MockFile* file = new MockFile();
     EXPECT_CALL(file_system, DoOpen(StrEq(license_path), IsCreateFileFlagSet()))
@@ -2954,7 +2956,7 @@ TEST_P(DeviceFilesUsageInfoTest, RetrieveByProviderSessionToken) {
   std::string path = device_base_path_ + file_name;
 
   size_t max_index_by_app_id = 0;
-  for (size_t i = 0; i < sizeof(kUsageInfoTestData) / sizeof(UsageInfo); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageInfoTestData); ++i) {
     if (app_id == kUsageInfoTestData[i].app_id) max_index_by_app_id = i;
   }
   std::string file_data =
@@ -3014,7 +3016,7 @@ TEST_P(DeviceFilesUsageInfoTest, UpdateUsageInfo) {
   std::vector<std::string> usage_data_fields;
 
   size_t max_index_by_app_id = 0;
-  for (size_t i = 0; i < sizeof(kUsageInfoTestData) / sizeof(UsageInfo); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageInfoTestData); ++i) {
     if (app_id == kUsageInfoTestData[i].app_id) {
       max_index_by_app_id = i;
 

libwvdrmengine/cdm/core/test/usage_table_header_unittest.cpp

@@ -6,8 +6,10 @@
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
+
 #include <string>
 
+#include "arraysize.h"
 #include "crypto_session.h"
 #include "device_files.h"
 #include "file_store.h"
@@ -103,8 +105,7 @@ const std::string kLicenseArray[] = {
     kUsageEntryInfoOfflineLicense2.key_set_id,
     kUsageEntryInfoOfflineLicense3.key_set_id,
 };
-const size_t kLicenseArraySize = sizeof(kLicenseArray)/
+const size_t kLicenseArraySize = ArraySize(kLicenseArray);
-    sizeof(kLicenseArray[0]);
 std::vector<std::string> kLicenseList;
 
 const std::vector<std::string> kEmptyUsageInfoFilesList;
@@ -114,8 +115,7 @@ const std::string kUsageInfoFileArray[] = {
     kUsageEntryInfoSecureStop2.usage_info_file_name,
     kUsageEntryInfoSecureStop3.usage_info_file_name,
 };
-const size_t kUsageInfoFileArraySize = sizeof(kUsageInfoFileArray)/
+const size_t kUsageInfoFileArraySize = ArraySize(kUsageInfoFileArray);
-    sizeof(kUsageInfoFileArray[0]);
 std::vector<std::string> kUsageInfoFileList;
 
 const DeviceFiles::CdmUsageData kCdmUsageData1 = {
@@ -322,6 +322,7 @@ class UsageTableHeaderTest : public WvCdmTestBase {
     // UsageTableHeader will take ownership of the pointer
     device_files_ = new MockDeviceFiles();
     crypto_session_ = new MockCryptoSession(&crypto_metrics_);
+
     usage_table_header_ = new UsageTableHeader();
 
     // usage_table_header_ object takes ownership of these objects

libwvdrmengine/cdm/test/cdm_feature_test.cpp

@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include "OEMCryptoCENC.h"
+#include "arraysize.h"
 #include "config_test_env.h"
 #include "license_protocol.pb.h"
 #include "license_request.h"
@@ -50,8 +51,6 @@ using ::testing::StrictMock;
 
 namespace {
 
-#define N_ELEM(a) (sizeof(a) / sizeof(a[0]))
-
 // HTTP response codes.
 const int kHttpOk = 200;
 // The following two responses are unused, but left here for human debuggers.
@@ -535,7 +534,7 @@ TEST_P(WvCdmSrmTest, Srm) {
 INSTANTIATE_TEST_CASE_P(
     Cdm, WvCdmSrmTest,
     ::testing::Range(&kSrmTestConfiguration[0],
-                     &kSrmTestConfiguration[N_ELEM(kSrmTestConfiguration)]));
+                     &kSrmTestConfiguration[ArraySize(kSrmTestConfiguration)]));
 
 // These parameterized tests validate SRM scenarios described in
 // SRM End-to-End Test Plan doc
@@ -585,6 +584,6 @@ TEST_P(WvCdmSrmNotSupportedTest, Srm) {
 INSTANTIATE_TEST_CASE_P(
     Cdm, WvCdmSrmNotSupportedTest,
     ::testing::Range(&kSrmNotSupportedTestConfiguration[0],
-                     &kSrmNotSupportedTestConfiguration[N_ELEM(
+                     &kSrmNotSupportedTestConfiguration[ArraySize(
                          kSrmNotSupportedTestConfiguration)]));
 }  // namespace wvcdm

libwvdrmengine/cdm/test/request_license_test.cpp

@@ -13,6 +13,8 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+#include "OEMCryptoCENC.h"
+#include "arraysize.h"
 #include "cdm_identifier.h"
 #include "config_test_env.h"
 #include "device_files.h"
@@ -23,7 +25,6 @@
 #include "license_request.h"
 #include "log.h"
 #include "oemcrypto_adapter.h"
-#include "OEMCryptoCENC.h"
 #include "properties.h"
 #include "string_conversions.h"
 #include "test_base.h"
@@ -47,8 +48,6 @@ using ::testing::UnorderedElementsAreArray;
 
 namespace {
 
-#define N_ELEM(a) (sizeof(a)/sizeof(a[0]))
-
 // HTTP response codes.
 const int kHttpOk = 200;
 
@@ -3776,7 +3775,7 @@ TEST_F(WvCdmRequestLicenseTest, UsageRemoveAllTest) {
   EXPECT_TRUE(handle.DeleteAllUsageInfoForApp(
                   DeviceFiles::GetUsageInfoFileName(""), &psts));
 
-  for (size_t i = 0; i < N_ELEM(usage_info_sub_samples_icp); ++i) {
+  for (size_t i = 0; i < ArraySize(usage_info_sub_samples_icp); ++i) {
     SubSampleInfo* data = usage_info_sub_samples_icp + i;
     property_set.set_app_id(i % 2 == 0 ? app_id_empty : app_id_not_empty);
     decryptor_->OpenSession(config_.key_system(), &property_set,
@@ -3874,7 +3873,7 @@ TEST_F(WvCdmRequestLicenseTest, RemoveCorruptedUsageInfoTest) {
   EXPECT_TRUE(handle.DeleteAllUsageInfoForApp(
                   DeviceFiles::GetUsageInfoFileName(""), &psts));
 
-  for (size_t i = 0; i < N_ELEM(usage_info_sub_samples_icp); ++i) {
+  for (size_t i = 0; i < ArraySize(usage_info_sub_samples_icp); ++i) {
     SubSampleInfo* data = usage_info_sub_samples_icp + i;
     property_set.set_app_id(i % 2 == 0 ? app_id_empty : app_id_not_empty);
     decryptor_->OpenSession(config_.key_system(), &property_set,
@@ -4020,7 +4019,7 @@ TEST_F(WvCdmRequestLicenseTest, RemoveCorruptedUsageInfoTest2) {
   EXPECT_TRUE(handle.DeleteAllUsageInfoForApp(
                   DeviceFiles::GetUsageInfoFileName(""), &psts));
 
-  for (size_t i = 0; i < N_ELEM(usage_info_sub_samples_icp); ++i) {
+  for (size_t i = 0; i < ArraySize(usage_info_sub_samples_icp); ++i) {
     SubSampleInfo* data = usage_info_sub_samples_icp + i;
     property_set.set_app_id(i % 2 == 0 ? app_id_empty : app_id_not_empty);
     decryptor_->OpenSession(config_.key_system(), &property_set,
@@ -4187,7 +4186,7 @@ TEST_F(WvCdmRequestLicenseTest, GetSecureStopIdsTest) {
   EXPECT_TRUE(retrieved_secure_stop_ids.empty());
 
   // First fetch licenses for the default app
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector1); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector1); ++i) {
     SubSampleInfo* data = kUsageLicenseTestVector1[i].sub_sample;
 
     property_set.set_app_id(app_id_empty);
@@ -4219,7 +4218,7 @@ TEST_F(WvCdmRequestLicenseTest, GetSecureStopIdsTest) {
   // Verify that there are usage records for the default identifier but
   // none yet for the non-default one
   std::vector<CdmSecureStopId> expected_provider_session_tokens;
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector1); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector1); ++i) {
     expected_provider_session_tokens.push_back(
         kUsageLicenseTestVector1[i].provider_session_token);
   }
@@ -4228,7 +4227,8 @@ TEST_F(WvCdmRequestLicenseTest, GetSecureStopIdsTest) {
       NO_ERROR,
       decryptor_->GetSecureStopIds(app_id_empty, kDefaultCdmIdentifier,
                                    &retrieved_secure_stop_ids));
-  EXPECT_EQ(N_ELEM(kUsageLicenseTestVector1), retrieved_secure_stop_ids.size());
+  EXPECT_EQ(ArraySize(kUsageLicenseTestVector1),
+            retrieved_secure_stop_ids.size());
   EXPECT_THAT(retrieved_secure_stop_ids,
       UnorderedElementsAreArray(expected_provider_session_tokens));
 
@@ -4240,7 +4240,7 @@ TEST_F(WvCdmRequestLicenseTest, GetSecureStopIdsTest) {
   EXPECT_TRUE(retrieved_secure_stop_ids.empty());
 
   // Now fetch licenses for the other identifier
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector2); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector2); ++i) {
     SubSampleInfo* data = kUsageLicenseTestVector2[i].sub_sample;
 
     property_set.set_app_id(kExampleIdentifier.app_package_name);
@@ -4278,14 +4278,15 @@ TEST_F(WvCdmRequestLicenseTest, GetSecureStopIdsTest) {
       decryptor_->GetSecureStopIds(kDefaultCdmIdentifier.app_package_name,
                                    kDefaultCdmIdentifier,
                                    &retrieved_secure_stop_ids));
-  EXPECT_EQ(N_ELEM(kUsageLicenseTestVector1), retrieved_secure_stop_ids.size());
+  EXPECT_EQ(ArraySize(kUsageLicenseTestVector1),
+            retrieved_secure_stop_ids.size());
   EXPECT_THAT(retrieved_secure_stop_ids,
       UnorderedElementsAreArray(expected_provider_session_tokens));
 
   retrieved_secure_stop_ids.clear();
   expected_provider_session_tokens.clear();
 
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector2); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector2); ++i) {
     expected_provider_session_tokens.push_back(
         kUsageLicenseTestVector2[i].provider_session_token);
   }
@@ -4295,7 +4296,8 @@ TEST_F(WvCdmRequestLicenseTest, GetSecureStopIdsTest) {
       decryptor_->GetSecureStopIds(kExampleIdentifier.app_package_name,
                                    kExampleIdentifier,
                                    &retrieved_secure_stop_ids));
-  EXPECT_EQ(N_ELEM(kUsageLicenseTestVector2), retrieved_secure_stop_ids.size());
+  EXPECT_EQ(ArraySize(kUsageLicenseTestVector2),
+            retrieved_secure_stop_ids.size());
   EXPECT_THAT(retrieved_secure_stop_ids,
       UnorderedElementsAreArray(expected_provider_session_tokens));
 
@@ -4447,7 +4449,7 @@ TEST_F(WvCdmRequestLicenseTest, UsageRemoveSecureStopTest) {
                   DeviceFiles::GetUsageInfoFileName(""), &psts));
 
   // First fetch licenses for the default app
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector1); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector1); ++i) {
     SubSampleInfo* data = kUsageLicenseTestVector1[i].sub_sample;
 
     property_set.set_app_id(app_id_empty);
@@ -4476,7 +4478,7 @@ TEST_F(WvCdmRequestLicenseTest, UsageRemoveSecureStopTest) {
   // Provision and fetch licenses for the other identifier
   Provision(kExampleIdentifier, kLevelDefault);
 
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector2); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector2); ++i) {
     SubSampleInfo* data = kUsageLicenseTestVector2[i].sub_sample;
 
     property_set.set_app_id(kExampleIdentifier.app_package_name);
@@ -4513,9 +4515,9 @@ TEST_F(WvCdmRequestLicenseTest, UsageRemoveSecureStopTest) {
       NO_ERROR,
       decryptor_->GetSecureStopIds(kDefaultCdmIdentifier.app_package_name,
                                    kDefaultCdmIdentifier, &secure_stop_ids));
-  EXPECT_EQ(N_ELEM(kUsageLicenseTestVector1), secure_stop_ids.size());
+  EXPECT_EQ(ArraySize(kUsageLicenseTestVector1), secure_stop_ids.size());
 
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector1); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector1); ++i) {
     EXPECT_EQ(
         NO_ERROR,
         decryptor_->RemoveUsageInfo(kDefaultCdmIdentifier.app_package_name,
@@ -4532,9 +4534,9 @@ TEST_F(WvCdmRequestLicenseTest, UsageRemoveSecureStopTest) {
       NO_ERROR,
       decryptor_->GetSecureStopIds(kExampleIdentifier.app_package_name,
                                    kExampleIdentifier, &secure_stop_ids));
-  EXPECT_EQ(N_ELEM(kUsageLicenseTestVector2), secure_stop_ids.size());
+  EXPECT_EQ(ArraySize(kUsageLicenseTestVector2), secure_stop_ids.size());
 
-  for (size_t i = 0; i < N_ELEM(kUsageLicenseTestVector2); ++i) {
+  for (size_t i = 0; i < ArraySize(kUsageLicenseTestVector2); ++i) {
     EXPECT_EQ(
         NO_ERROR,
         decryptor_->RemoveUsageInfo(kExampleIdentifier.app_package_name,
@@ -5807,7 +5809,7 @@ TEST_P(WvCenc30SwitchCipherModeTest, DecryptionTest) {
   CdmKeyStatusMap key_status_map = listener.GetKeyStatusMap();
   EXPECT_EQ(8u, key_status_map.size());
 
-  for (size_t i = 0; i < N_ELEM(info->sample_info); ++i) {
+  for (size_t i = 0; i < ArraySize(info->sample_info); ++i) {
     Cenc30SampleInfo* data = &info->sample_info[i];
     std::vector<uint8_t> output_buffer(data->encrypted_data.size(), 0);
     std::vector<uint8_t> iv(data->iv.begin(), data->iv.end());

libwvdrmengine/cdm/util/include/arraysize.h

@@ -0,0 +1,20 @@
+// Copyright 2019 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+
+#ifndef WVCDM_UTIL_ARRAYSIZE_H_
+#define WVCDM_UTIL_ARRAYSIZE_H_
+
+#include <stdint.h>
+
+namespace wvcdm {
+
+// Returns the size of a fixed-length array.
+template <typename T, size_t N>
+constexpr size_t ArraySize(const T (&)[N]) {
+  return N;
+}
+
+}  // namespace wvcdm
+
+#endif  // WVCDM_UTIL_ARRAYSIZE_H_