[cxx]: simple spi master class

* spi cxx unit test (CATCH-based, on host)
* added portmacro.h to driver mocking
* added simple testing app to write/read SPI,
  using an MPU9250

examples/cxx/experimental/experimental_cpp_component/host_test/system/CMakeLists.txt

@@ -0,0 +1,34 @@
+cmake_minimum_required(VERSION 3.5)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+set(COMPONENTS main)
+
+idf_component_set_property(driver USE_MOCK 1)
+
+# Overriding components which should be mocked
+list(APPEND EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/tools/mocks/driver/")
+list(APPEND EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/tools/mocks/freertos/")
+
+# Including experimental component here because it's outside IDF's main component directory
+list(APPEND EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/examples/cxx/experimental/experimental_cpp_component/")
+project(test_system_cxx_host)
+
+add_custom_command(
+    OUTPUT "${CMAKE_CURRENT_SOURCE_DIR}/build/coverage.info"
+    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/build"
+    COMMAND lcov --capture --directory . --output-file coverage.info
+    COMMENT "Create coverage report"
+    )
+
+add_custom_command(
+    OUTPUT "${CMAKE_CURRENT_SOURCE_DIR}/build/coverage_report/"
+    DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/build/coverage.info"
+    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/build"
+    COMMAND genhtml coverage.info --output-directory coverage_report/
+    COMMENT "Turn coverage report into html-based visualization"
+    )
+
+add_custom_target(coverage
+    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/build"
+    DEPENDS "coverage_report/"
+    )

examples/cxx/experimental/experimental_cpp_component/host_test/system/README.md

@@ -0,0 +1,8 @@
+| Supported Targets | Linux |
+| ----------------- | ----- |
+
+# Build
+`idf.py build` (sdkconfig.defaults sets the linux target by default)
+
+# Run
+`build/system_cxx_host_test.elf`

examples/cxx/experimental/experimental_cpp_component/host_test/system/main/CMakeLists.txt

@@ -0,0 +1,12 @@
+idf_component_get_property(cpp_component experimental_cpp_component COMPONENT_DIR)
+
+idf_component_register(SRCS "system_cxx_test.cpp"
+                    "${cpp_component}/esp_exception.cpp"
+                    INCLUDE_DIRS
+                    "."
+                    "${cpp_component}/include"
+                    $ENV{IDF_PATH}/tools/catch
+                    REQUIRES driver)
+
+target_compile_options(${COMPONENT_LIB} PUBLIC --coverage)
+target_link_libraries(${COMPONENT_LIB} --coverage)

examples/cxx/experimental/experimental_cpp_component/host_test/system/main/system_cxx_test.cpp

@@ -0,0 +1,95 @@
+/*
+ * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: CC0
+ *
+ * This test code is in the Public Domain (or CC0 licensed, at your option.)
+ *
+ * Unless required by applicable law or agreed to in writing, this
+ * software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, either express or implied.
+ */
+
+#define CATCH_CONFIG_MAIN
+
+#include "catch.hpp"
+#include "system_cxx.hpp"
+
+// TODO: IDF-2693, function definition just to satisfy linker, mock esp_common instead
+const char *esp_err_to_name(esp_err_t code) {
+    return "test";
+}
+
+using namespace std;
+using namespace idf;
+
+TEST_CASE("Frequency invalid")
+{
+    CHECK_THROWS_AS(Frequency(0), ESPException&);
+}
+
+TEST_CASE("Frequency constructors correct")
+{
+    Frequency f0(440);
+    CHECK(440 == f0.get_value());
+    Frequency f1 = Frequency::Hz(440);
+    CHECK(440 == f1.get_value());
+    Frequency f2 = Frequency::KHz(440);
+    CHECK(440000 == f2.get_value());
+    Frequency f3 = Frequency::MHz(440);
+    CHECK(440000000 == f3.get_value());
+}
+
+TEST_CASE("Frequency op ==")
+{
+    Frequency f0(440);
+    Frequency f1(440);
+    CHECK(f1 == f0);
+}
+
+TEST_CASE("Frequency op !=")
+{
+    Frequency f0(440);
+    Frequency f1(441);
+    CHECK(f1 != f0);
+}
+
+TEST_CASE("Frequency op >")
+{
+    Frequency f0(440);
+    Frequency f1(441);
+    Frequency f2(440);
+    CHECK(f1 > f0);
+    CHECK(!(f0 > f1));
+    CHECK(!(f0 > f2));
+}
+
+TEST_CASE("Frequency op <")
+{
+    Frequency f0(440);
+    Frequency f1(441);
+    Frequency f2(440);
+    CHECK(f0 < f1);
+    CHECK(!(f1 < f0));
+    CHECK(!(f0 < f2));
+}
+
+TEST_CASE("Frequency op >=")
+{
+    Frequency f0(440);
+    Frequency f1(441);
+    Frequency f2(440);
+    CHECK  (f1 >= f0);
+    CHECK(!(f0 >= f1));
+    CHECK  (f0 >= f2);
+}
+
+TEST_CASE("Frequency op <=")
+{
+    Frequency f0(440);
+    Frequency f1(441);
+    Frequency f2(440);
+    CHECK  (f0 <= f1);
+    CHECK(!(f1 <= f0));
+    CHECK  (f0 <= f2);
+}

examples/cxx/experimental/experimental_cpp_component/host_test/system/sdkconfig.defaults

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+CONFIG_UNITY_ENABLE_IDF_TEST_RUNNER=n
+CONFIG_IDF_TARGET="linux"
+CONFIG_CXX_EXCEPTIONS=y