CMake: Make qtgrpc tests standalone projects

Add the boilerplate standalone test prelude to each test, so that they
can be opened with an IDE without the qt-cmake-standalone-test script,
but directly with qt-cmake or cmake.

Boilerplate was added using the following scripts:
https://git.qt.io/alcroito/cmake_refactor

Manual adjustments were made where the code was inserted in the wrong
location.

Adapt the grpc client tests manually to make them work in standalone
variant. Also some projects are renamed manually since their
subdirectories contain more than one test target, so the target
name doesn't reflect the project scope.

Task-number: QTBUG-93020
Change-Id: Ifa68664073c5947f28db0a67bab25521d4f9a523
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>

tests/auto/grpc/client/CMakeLists.txt

@@ -1,6 +1,14 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_grpc_client LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+
+    include("../shared/test_server/CMakeLists.txt")
+endif()
+
 if(NOT TARGET testserver)
     return()
 endif()
@@ -24,6 +32,8 @@ qt_internal_add_test(tst_grpc_client
         tst_grpc_client.cpp
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_SOURCE_DIR}/../shared
+    DEFINES
+        TEST_GRPC_SERVER_PATH="$<TARGET_FILE:testserver>"
     LIBRARIES
         Qt::Test
         Qt::Core

tests/auto/grpc/client/tst_grpc_client.cpp

@@ -26,6 +26,7 @@
 #  include <grpcpp/security/credentials.h>
 #endif
 #include "testservice_client.grpc.qpb.h"
+#include <message_latency_defs.h>
 
 using namespace Qt::Literals::StringLiterals;
 
@@ -156,7 +157,7 @@ private:
     void startServer()
     {
         serverProc = std::make_unique<QProcess>();
-        QString serverPath = QFINDTESTDATA("../shared/test_server/testserver");
+        QString serverPath = QFINDTESTDATA(TEST_GRPC_SERVER_PATH);
         QVERIFY2(!serverPath.isEmpty(), "testserver binary is missing");
         QObject::connect(serverProc.get(), &QProcess::readyReadStandardOutput, this,
                          [this] { qInfo() << serverProc->readAllStandardOutput(); });

tests/auto/grpc/server/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_grpc_server LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_grpc_server_qtgrpc_gen
     PROTO_FILES
         ${CMAKE_CURRENT_SOURCE_DIR}/../shared/proto/testservice.proto

tests/auto/grpc/shared/message_latency_defs.h

@@ -0,0 +1,6 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#ifndef QT_GRPC_TEST_MESSAGE_LATENCY
+#  define QT_GRPC_TEST_MESSAGE_LATENCY 300
+#endif

tests/auto/grpc/shared/test_server/CMakeLists.txt

@@ -50,11 +50,15 @@ target_link_libraries(TestServerRunner_grpc_gen
 
 add_library(TestServerRunner
     STATIC
-        testserverrunner.cpp
-        testserverrunner.h
+        ${CMAKE_CURRENT_LIST_DIR}/testserverrunner.cpp
+        ${CMAKE_CURRENT_LIST_DIR}/testserverrunner.h
 )
 
-target_include_directories(TestServerRunner PRIVATE ${out_dir})
+target_include_directories(TestServerRunner
+    PRIVATE
+        ${out_dir}
+        ${CMAKE_CURRENT_LIST_DIR}/..
+)
 
 target_link_libraries(TestServerRunner
     PRIVATE
@@ -63,18 +67,23 @@ target_link_libraries(TestServerRunner
         Qt6::Core
 )
 
+set_source_files_properties("${CMAKE_CURRENT_LIST_DIR}/assets/cert.pem"
+    PROPERTIES QT_RESOURCE_ALIAS assets/cert.pem)
+set_source_files_properties("${CMAKE_CURRENT_LIST_DIR}/assets/key.pem"
+    PROPERTIES QT_RESOURCE_ALIAS assets/key.pem)
+
 qt_add_resources(TestServerRunner
     "keys"
     PREFIX
         "/"
     FILES
-        "assets/cert.pem"
-        "assets/key.pem"
+        "${CMAKE_CURRENT_LIST_DIR}/assets/cert.pem"
+        "${CMAKE_CURRENT_LIST_DIR}/assets/key.pem"
 )
 
 qt_internal_add_executable(testserver
     SOURCES
-        testserver.cpp
+        ${CMAKE_CURRENT_LIST_DIR}/testserver.cpp
     LIBRARIES
         TestServerRunner
     OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/"
@@ -83,7 +92,7 @@ qt_internal_add_executable(testserver
 
 qt_internal_add_executable(securetestserver
     SOURCES
-        securetestserver.cpp
+        ${CMAKE_CURRENT_LIST_DIR}/securetestserver.cpp
     LIBRARIES
         TestServerRunner
     OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/"

tests/auto/grpc/shared/test_server/testserverrunner.cpp

@@ -8,6 +8,8 @@
 #include <QString>
 
 #include "testservice.grpc.pb.h"
+#include <message_latency_defs.h>
+
 #include <grpc++/grpc++.h>
 
 #include <memory>

tests/auto/grpc/ssl_client/CMakeLists.txt

@@ -1,6 +1,14 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_grpc_ssl_client LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+
+    include("../shared/test_server/CMakeLists.txt")
+endif()
+
 if(NOT TARGET securetestserver)
     return()
 endif()
@@ -25,6 +33,8 @@ qt_internal_add_test(tst_grpc_ssl_client
         tst_grpc_ssl_client.cpp
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_SOURCE_DIR}/../shared
+    DEFINES
+        TEST_GRPC_SERVER_PATH="$<TARGET_FILE:securetestserver>"
     LIBRARIES
         Qt::Test
         Qt::Core

tests/auto/grpc/ssl_client/tst_grpc_ssl_client.cpp

@@ -68,7 +68,7 @@ private:
     void startServer()
     {
         serverProc = std::make_unique<QProcess>();
-        QString serverPath = QFINDTESTDATA("../shared/test_server/securetestserver");
+        QString serverPath = QFINDTESTDATA(TEST_GRPC_SERVER_PATH);
         QVERIFY2(!serverPath.isEmpty(), "securetestserver binary is missing");
         serverProc->start(serverPath);
         serverProc->waitForStarted();

tests/auto/grpc/unattached_channel/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_grpc_unattached_channel LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_grpc_unattached_channel_qtgrpc_gen
     PROTO_FILES
         ${CMAKE_CURRENT_SOURCE_DIR}/../shared/proto/testservice.proto

tests/auto/grpcgen/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qtgrpcgen LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_qtgrpcgen
     SOURCES
         tst_qtgrpcgen.cpp

tests/auto/protobuf/basic/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_basic LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_basictypes_gen
     PROTO_FILES
         proto/basicmessages.proto

tests/auto/protobuf/converters/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_converters LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_converter
     SOURCES
         tst_protobuf_converter.cpp

tests/auto/protobuf/duplicated_metatypes/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_duplicated_metatypes LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_duplicatedmetatypes
     SOURCES
         tst_protobuf_duplicatedmetatypes.cpp

tests/auto/protobuf/enums/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_enums LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_enumtypes_gen
     PROTO_FILES
         enummessages.proto

tests/auto/protobuf/externalpackage/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_externalpackage LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_externalpackage
     SOURCES
         tst_protobuf_externalpackage.cpp

tests/auto/protobuf/extranamespace/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_extranamespace LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_extranamespace_qtprotobuf_gen
     OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/qt_protobuf_generated"
     PROTO_FILES proto/extranamespace.proto

tests/auto/protobuf/nested/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_nested LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_nestedtypes_qtprotobuf_gen
     PROTO_FILES
         proto/nestedmessages.proto

tests/auto/protobuf/nopackage/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_nopackage LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_nopackagetypes_qtprotobuf_gen
     PROTO_FILES
         ../../shared/data/proto/nopackage.proto

tests/auto/protobuf/qprotobuflazymessagepointer/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qprotobuflazymessagepointer LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_qprotobuflazymessagepointer
     SOURCES
         tst_qprotobuflazymessagepointer.cpp

tests/auto/protobuf/qprotobufoneof/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qprotobufoneof LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_qprotobufoneof
     SOURCES
         tst_qprotobufoneof.cpp

tests/auto/protobuf/recursive/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_recursive LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_recursive_gen
     PROTO_FILES
         recursive.proto

tests/auto/protobuf/sequence/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_sequence LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_sequence
     SOURCES
         tst_protobuf_sequence.cpp

tests/auto/protobuf/syntax/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_syntax LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt6_add_protobuf(tst_protobuf_syntax_qtprotobuf_gen
     PROTO_FILES
         ../../shared/data/proto/syntax.proto

tests/auto/protobuf/wellknown/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_wellknown LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_any
     SOURCES
         tst_protobuf_any.cpp

tests/auto/protobufgen/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qtprotobufgen LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_qtprotobufgen
     SOURCES
         tst_qtprotobufgen.cpp

tests/auto/protobufqml/basic/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_basic_qml LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_basictypes_qml
     QMLTEST
     SOURCES

tests/auto/protobufqml/enums/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_enums_qml LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_enumtypes_qml
     QMLTEST
     SOURCES

tests/auto/protobufqml/messagelists/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_messagelists_qml LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_repeated_qml
     QMLTEST
     SOURCES

tests/auto/protobufqml/nested/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_nested_qml LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_nestedtypes_qtprotobuf_qmltest
     QMLTEST
     SOURCES

tests/auto/protobufqml/nopackage/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_nopackage_qml LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_nopackage_qml
     QMLTEST
     SOURCES

tests/auto/protobufqml/syntax/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2023 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_syntax_qml LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_syntax_qml
     QMLTEST
     SOURCES

tests/auto/protobufqttypes/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_protobuf_protobufqttypes LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
 qt_internal_add_test(tst_protobuf_qtcoretypes
     SOURCES
         qtprotobufqttypescoretest.cpp