kernel: add Catch2 string makers for printable test output

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 197 insertions, 0 deletions

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index ca44e79b..fc25f1ca 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -193,6 +193,10 @@ if(BUILD_TESTING)
         ${KERNEL_TEST_SUPPORT_SOURCES}
     )
 
+    target_compile_options("${TEST_TARGET}" PRIVATE
+        "SHELL:-include ${CMAKE_CURRENT_SOURCE_DIR}/kernel/test_support/string_makers.hpp"
+    )
+
     target_compile_definitions("${TEST_TARGET}" PRIVATE
         KERNEL_TEST_ASSETS_DIR="${CMAKE_CURRENT_SOURCE_DIR}/kernel/test_support/vfs/test_assets"
     )
diff --git a/kernel/kernel/test_support/string_makers.hpp b/kernel/kernel/test_support/string_makers.hpp
new file mode 100644
index 00000000..98eed3e8
--- /dev/null
+++ b/kernel/kernel/test_support/string_makers.hpp
@@ -0,0 +1,132 @@
+#ifndef TEACHOS_KERNEL_TEST_SUPPORT_STRING_MAKERS_HPP
+#define TEACHOS_KERNEL_TEST_SUPPORT_STRING_MAKERS_HPP
+
+//! Catch2 string conversions for kapi and kernel types.
+//!
+//! This header is force-included into every kernel test translation unit by the build system and must therefore never
+//! be included by kernel code. See kstd/test_support/string_makers.hpp for the conversions of kstd types.
+
+#include <kstd/test_support/string_makers.hpp>  // IWYU pragma: export
+
+#include <kapi/devices.hpp>
+#include <kapi/filesystem.hpp>
+#include <kapi/memory.hpp>
+
+#include <catch2/catch_tostring.hpp>
+
+#include <string>
+
+namespace Catch
+{
+
+  template<>
+  struct StringMaker<kapi::filesystem::device_number>
+  {
+    static auto convert(kapi::filesystem::device_number number) -> std::string
+    {
+      return std::to_string(number.major) + ':' + std::to_string(number.minor);
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::filesystem::directory_cursor>
+  {
+    static auto convert(kapi::filesystem::directory_cursor cursor) -> std::string
+    {
+      return "directory_cursor{" + std::to_string(cursor.value) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::filesystem::file_status>
+  {
+    static auto convert(kapi::filesystem::file_status const & status) -> std::string
+    {
+      return "file_status{mode: " + Catch::Detail::stringify(status.mode) +
+             ", size: " + Catch::Detail::stringify(status.size) +
+             ", raw_device: " + Catch::Detail::stringify(status.raw_device) +
+             ", inode_number: " + Catch::Detail::stringify(status.inode_number) +
+             ", link_count: " + Catch::Detail::stringify(status.link_count) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::memory::frame>
+  {
+    static auto convert(kapi::memory::frame frame) -> std::string
+    {
+      return "frame{" + std::to_string(frame.number()) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::memory::page>
+  {
+    static auto convert(kapi::memory::page page) -> std::string
+    {
+      return "page{" + std::to_string(page.number()) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::devices::mmio_range>
+  {
+    static auto convert(kapi::devices::mmio_range const & range) -> std::string
+    {
+      return "mmio{" + Catch::Detail::stringify(range.start) + ", " + Catch::Detail::stringify(range.size) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::devices::io_port>
+  {
+    static auto convert(kapi::devices::io_port const & port) -> std::string
+    {
+      return "port{" + std::to_string(port.start) + ", " + std::to_string(port.count) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::devices::interrupt_line>
+  {
+    static auto convert(kapi::devices::interrupt_line const & line) -> std::string
+    {
+      return "irq{" + std::to_string(line.number) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::devices::dma_channel>
+  {
+    static auto convert(kapi::devices::dma_channel const & channel) -> std::string
+    {
+      return "dma{" + std::to_string(channel.number) + '}';
+    }
+  };
+
+  template<>
+  struct StringMaker<kapi::devices::resource>
+  {
+    static auto convert(kapi::devices::resource const & resource) -> std::string
+    {
+      using kapi::devices::resource_type;
+
+      switch (resource.type)
+      {
+        case resource_type::mmio:
+          return Catch::Detail::stringify(resource.get<resource_type::mmio>());
+        case resource_type::port:
+          return Catch::Detail::stringify(resource.get<resource_type::port>());
+        case resource_type::irq:
+          return Catch::Detail::stringify(resource.get<resource_type::irq>());
+        case resource_type::dma:
+          return Catch::Detail::stringify(resource.get<resource_type::dma>());
+      }
+
+      return "resource{<unknown>}";
+    }
+  };
+
+}  // namespace Catch
+
+#endif
diff --git a/kernel/kernel/test_support/string_makers.tests.cpp b/kernel/kernel/test_support/string_makers.tests.cpp
new file mode 100644
index 00000000..1bcb332f
--- /dev/null
+++ b/kernel/kernel/test_support/string_makers.tests.cpp
@@ -0,0 +1,61 @@
+#include <kernel/test_support/string_makers.hpp>
+
+#include <kapi/devices.hpp>
+#include <kapi/filesystem.hpp>
+#include <kapi/memory.hpp>
+
+#include <kstd/units.hpp>
+
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/catch_tostring.hpp>
+
+using namespace kstd::units_literals;
+
+SCENARIO("Catch2 string conversion of kapi types", "[test_support][string_makers]")
+{
+  GIVEN("filesystem types")
+  {
+    auto const number = kapi::filesystem::device_number{.major = 1, .minor = 2};
+    auto const cursor = kapi::filesystem::directory_cursor{3};
+    auto const status = kapi::filesystem::file_status{
+        .mode = 4, .size = 5_B, .raw_device = number, .inode_number = 6, .link_count = 7};
+
+    THEN("they are printed with their fields")
+    {
+      REQUIRE(Catch::Detail::stringify(number) == "1:2");
+      REQUIRE(Catch::Detail::stringify(cursor) == "directory_cursor{3}");
+      REQUIRE(Catch::Detail::stringify(status) ==
+              "file_status{mode: 4, size: 5, raw_device: 1:2, inode_number: 6, link_count: 7}");
+    }
+  }
+
+  GIVEN("memory chunks")
+  {
+    THEN("they are printed with their number")
+    {
+      REQUIRE(Catch::Detail::stringify(kapi::memory::frame{8}) == "frame{8}");
+      REQUIRE(Catch::Detail::stringify(kapi::memory::page{9}) == "page{9}");
+    }
+  }
+
+  GIVEN("device resources")
+  {
+    auto const port = kapi::devices::io_port{.start = 0x60, .count = 2};
+    auto const line = kapi::devices::interrupt_line{.number = 1};
+    auto const channel = kapi::devices::dma_channel{.number = 3};
+
+    THEN("they are printed with their kind and fields")
+    {
+      REQUIRE(Catch::Detail::stringify(port) == "port{96, 2}");
+      REQUIRE(Catch::Detail::stringify(line) == "irq{1}");
+      REQUIRE(Catch::Detail::stringify(channel) == "dma{3}");
+    }
+
+    THEN("a resource is printed like the value it holds")
+    {
+      REQUIRE(Catch::Detail::stringify(kapi::devices::resource{port}) == "port{96, 2}");
+      REQUIRE(Catch::Detail::stringify(kapi::devices::resource{line}) == "irq{1}");
+      REQUIRE(Catch::Detail::stringify(kapi::devices::resource{channel}) == "dma{3}");
+    }
+  }
+}