Add a host-native unit test harness

.gitignore

@@ -27,8 +27,7 @@
 /FMDC_V03/
 /Duet3_MB6HC_no_SD/
 /Duet3_MB6HC_no_S_curve/
-/INDX/
+/tests/build/
 /.clangd
 /.clang-format
 /src/Temp/
-/.settings/

tests/Makefile

@@ -0,0 +1,102 @@
+# RepRapFirmware host-native test build
+
+CXX ?= g++-15
+
+ifeq ($(V),1)
+	Q :=
+else
+	Q := @
+endif
+
+ROOT := ..
+WORKSPACE := ../..
+BUILD_DIR := build
+TARGET := $(BUILD_DIR)/rrf_host_tests
+
+CPPFLAGS := \
+	-I$(CURDIR)/support/shims \
+	-I$(ROOT) \
+	-I$(ROOT)/src \
+	-I$(WORKSPACE)/CANlib/src \
+	-I$(WORKSPACE)/RRFLibraries/src \
+	-I$(CURDIR)/support
+
+# RRFLibraries/src/General must NOT be on the include path: it holds String.h, which on a
+# case-insensitive filesystem (macOS) libc++'s <cstring> finds in place of the real <string.h>.
+# Sources reach those headers through the General/ and Math/ prefixes instead.
+CXXFLAGS ?= -std=gnu++20 -O2 -Wall -Wextra -Wpedantic
+
+# unit/test_fopdt.cpp is excluded: it targets the pre-3.7.0-beta.3 FopDt API (CorrectPwmForVoltage,
+# SetM301PidParameters, ArePidParametersOverridden, AppendM301Command, 3-argument EstimateRequiredPwm),
+# all of which have since changed. It needs updating by whoever owns the heater model.
+TEST_SOURCES := \
+	support/TestMain.cpp \
+	unit/test_bitmap.cpp \
+	unit/test_deviation.cpp \
+	unit/test_isqrt.cpp
+
+LIB_SOURCES := \
+	$(WORKSPACE)/RRFLibraries/src/General/SafeVsnprintf.cpp \
+	$(WORKSPACE)/RRFLibraries/src/General/StringFunctions.cpp \
+	$(WORKSPACE)/RRFLibraries/src/General/StringRef.cpp \
+	$(WORKSPACE)/RRFLibraries/src/General/Strnlen.cpp \
+	$(WORKSPACE)/RRFLibraries/src/Math/Deviation.cpp \
+	$(WORKSPACE)/RRFLibraries/src/Math/Isqrt.cpp
+
+OBJECTS := $(patsubst %.cpp,$(BUILD_DIR)/%.o,$(TEST_SOURCES)) \
+	$(BUILD_DIR)/rrflibraries/SafeVsnprintf.o \
+	$(BUILD_DIR)/rrflibraries/StringFunctions.o \
+	$(BUILD_DIR)/rrflibraries/StringRef.o \
+	$(BUILD_DIR)/rrflibraries/Strnlen.o \
+	$(BUILD_DIR)/rrflibraries/Deviation.o \
+	$(BUILD_DIR)/rrflibraries/Isqrt.o
+
+.PHONY: all clean run
+
+all: run
+
+run: $(TARGET)
+	$(Q)./$(TARGET)
+
+$(TARGET): $(OBJECTS)
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CXXFLAGS) $^ -o $@
+
+$(BUILD_DIR)/support/%.o: support/%.cpp support/TestRunner.h
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/unit/%.o: unit/%.cpp support/TestRunner.h
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/rrflibraries/Isqrt.o: $(WORKSPACE)/RRFLibraries/src/Math/Isqrt.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/rrflibraries/SafeVsnprintf.o: $(WORKSPACE)/RRFLibraries/src/General/SafeVsnprintf.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/rrflibraries/StringFunctions.o: $(WORKSPACE)/RRFLibraries/src/General/StringFunctions.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/rrflibraries/StringRef.o: $(WORKSPACE)/RRFLibraries/src/General/StringRef.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/rrflibraries/Strnlen.o: $(WORKSPACE)/RRFLibraries/src/General/Strnlen.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/rrflibraries/Deviation.o: $(WORKSPACE)/RRFLibraries/src/Math/Deviation.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/reprapfirmware/FOPDT.o: $(ROOT)/src/Heating/FOPDT.cpp
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
+
+clean:
+	$(Q)rm -rf $(BUILD_DIR)

tests/README.md

@@ -0,0 +1,51 @@
+# Host-Native Tests
+
+This directory contains Linux-hosted tests for code that can be validated without running on a Duet board.
+
+The initial scope is intentionally narrow:
+
+- pure math and algorithm code that does not require MCU peripherals
+- selected firmware-side model code compiled against narrow test-only shims
+- deterministic tests that run with the system C++ compiler
+- no dependency on the ARM cross-toolchain
+
+Run the tests from the RepRapFirmware root:
+
+```sh
+make test-host
+```
+
+Current contents:
+
+- `support/` - minimal in-repo test runner
+- `support/shims/` - narrow host-only shims for firmware types needed by selected model code
+- `unit/` - host-native unit tests
+- `make test-host` from the repository root builds and runs the suite with `g++`
+
+Current coverage:
+
+- RRFLibraries helpers: bitmap, deviation, integer square root, fast square root
+- RepRapFirmware heater model: `FOPDT`
+
+Planned next steps:
+
+- add deterministic time and captured-output test support
+- add more RepRapFirmware-side tests for kinematics and control logic
+## Why the motion system is not testable here
+
+`Move.cpp` needs 98 RepRapFirmware headers across 18 subsystems just to parse,
+and its body calls `reprap.GetGCodes()` 91 times, plus `GetPlatform()`,
+`GetExpansion()` and `GetPortControl()`. `Move` and `DDA` are not separable from
+the `reprap` singleton, so reaching the planner from here would mean either a
+large fake Platform/GCodes layer or refactoring `Move` onto interfaces.
+
+Until that changes, host tests are limited to leaf code. Validating motion
+behaviour - junction blending, speed ceilings, deceleration on loss of input -
+needs a peripheral-level emulator such as Renode.
+
+Measure it again before believing it:
+
+```sh
+make Duet3_MB6HC ...                       # produces the .d files
+tr ' ' '\n' < Duet3_MB6HC/src/Movement/Move.d | grep -E '^src/.*\.h$' | sort -u | wc -l
+```

tests/support/TestMain.cpp

@@ -0,0 +1,8 @@
+#include <cstdio>
+
+#include "TestRunner.h"
+
+int main()
+{
+	return test::RunAllTests();
+}

tests/support/TestRunner.h

@@ -0,0 +1,129 @@
+#ifndef RRF_TEST_RUNNER_H
+#define RRF_TEST_RUNNER_H
+
+#include <cmath>
+#include <cstdio>
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace test
+{
+	using TestFunction = void (*)();
+
+	struct TestCase
+	{
+		const char* name;
+		TestFunction function;
+	};
+
+	inline std::vector<TestCase>& Registry()
+	{
+		static std::vector<TestCase> registry;
+		return registry;
+	}
+
+	class Registrar
+	{
+	public:
+		Registrar(const char* name, TestFunction function)
+		{
+			Registry().push_back({name, function});
+		}
+	};
+
+	class Failure : public std::runtime_error
+	{
+	public:
+		explicit Failure(const std::string& message)
+			: std::runtime_error(message)
+		{
+		}
+	};
+
+	[[noreturn]] inline void Fail(const char* file, int line, const std::string& message)
+	{
+		std::ostringstream stream;
+		stream << file << ':' << line << ": " << message;
+		throw Failure(stream.str());
+	}
+
+	template <typename T, typename U>
+	void ExpectEqual(const T& actual, const U& expected, const char* file, int line, const char* actualExpr, const char* expectedExpr)
+	{
+		if (!(actual == expected))
+		{
+			std::ostringstream stream;
+			stream << "expected " << actualExpr << " == " << expectedExpr << ", got " << actual << " and " << expected;
+			Fail(file, line, stream.str());
+		}
+	}
+
+	template <typename T, typename U, typename V>
+	void ExpectNear(const T& actual, const U& expected, const V& tolerance, const char* file, int line, const char* actualExpr, const char* expectedExpr, const char* toleranceExpr)
+	{
+		const auto delta = std::fabs(static_cast<double>(actual) - static_cast<double>(expected));
+		if (delta > static_cast<double>(tolerance))
+		{
+			std::ostringstream stream;
+			stream << "expected " << actualExpr << " ~= " << expectedExpr << " within " << toleranceExpr
+				   << ", got delta " << delta;
+			Fail(file, line, stream.str());
+		}
+	}
+
+	inline void ExpectTrue(bool condition, const char* file, int line, const char* expression)
+	{
+		if (!condition)
+		{
+			std::ostringstream stream;
+			stream << "expected true: " << expression;
+			Fail(file, line, stream.str());
+		}
+	}
+
+	inline int RunAllTests()
+	{
+		int failures = 0;
+		for (const TestCase& testCase : Registry())
+		{
+			try
+			{
+				testCase.function();
+			}
+			catch (const Failure& failure)
+			{
+				++failures;
+				std::fprintf(stderr, "[FAIL] %s\n  %s\n", testCase.name, failure.what());
+				continue;
+			}
+			catch (const std::exception& exception)
+			{
+				++failures;
+				std::fprintf(stderr, "[FAIL] %s\n  unexpected exception: %s\n", testCase.name, exception.what());
+				continue;
+			}
+
+			std::fprintf(stdout, "[PASS] %s\n", testCase.name);
+		}
+
+		std::fprintf(stdout, "Ran %zu test(s), %d failure(s)\n", Registry().size(), failures);
+		return failures;
+	}
+}
+
+#define TEST_CASE(name) \
+	static void name(); \
+	static test::Registrar name##_registrar(#name, &name); \
+	static void name()
+
+#define EXPECT_TRUE(expr) test::ExpectTrue((expr), __FILE__, __LINE__, #expr)
+#define EXPECT_EQ(actual, expected) test::ExpectEqual((actual), (expected), __FILE__, __LINE__, #actual, #expected)
+#define EXPECT_NEAR(actual, expected, tolerance) test::ExpectNear((actual), (expected), (tolerance), __FILE__, __LINE__, #actual, #expected, #tolerance)
+
+#endif

tests/support/shims/ObjectModel/ObjectModel.h

@@ -0,0 +1,6 @@
+#ifndef RRF_HOST_TEST_OBJECTMODEL_H
+#define RRF_HOST_TEST_OBJECTMODEL_H
+
+#include "../RepRapFirmware.h"
+
+#endif

tests/support/shims/RepRapFirmware.h

@@ -0,0 +1,37 @@
+#ifndef RRF_HOST_TEST_REPRAPFIRMWARE_H
+#define RRF_HOST_TEST_REPRAPFIRMWARE_H
+
+#include <cstdarg>
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <string>
+
+#include "../../../../RRFLibraries/src/ecv_duet3d.h"
+#include "../../../../RRFLibraries/src/General/SimpleMath.h"
+#include "../../../../RRFLibraries/src/General/String.h"
+#include "../../../../RRFLibraries/src/General/StringRef.h"
+
+#define SUPPORT_OBJECT_MODEL 0
+#define HAS_MASS_STORAGE 0
+#define HAS_SBC_INTERFACE 0
+#define SUPPORT_CAN_EXPANSION 0
+
+#ifndef THROWS
+#define THROWS(...) noexcept(false)
+#endif
+
+#ifndef INHERIT_OBJECT_MODEL
+#define INHERIT_OBJECT_MODEL
+#endif
+
+#ifndef DECLARE_OBJECT_MODEL
+#define DECLARE_OBJECT_MODEL
+#endif
+
+constexpr float NormalAmbientTemperature = 25.0;
+constexpr unsigned int MaxFloatDigitsDisplayedAfterPoint = 3;
+
+#define DEGREE_SYMBOL " "
+
+#endif