Initial DSP debugger work

src/panda_qt/dsp_debugger.cpp

@@ -0,0 +1,242 @@
+#include "panda_qt/dsp_debugger.hpp"
+
+#include <fmt/format.h>
+
+#include <QCheckBox>
+#include <QGridLayout>
+#include <QHBoxLayout>
+#include <QListWidget>
+#include <QPlainTextEdit>
+#include <QPushButton>
+#include <limits>
+#include <span>
+#include <utility>
+
+#include "teakra/disassembler.h"
+
+// TODO: Make this actually thread-safe by having it only work when paused
+static int getLinesInViewport(QListWidget* listWidget) {
+	auto viewportHeight = listWidget->viewport()->height();
+	QFontMetrics fm = QFontMetrics(listWidget->font());
+	auto lineHeight = fm.height();
+
+	return int(viewportHeight / lineHeight);
+}
+
+static std::pair<int, int> getVisibleLineRange(QListWidget* listWidget, QScrollBar* scrollBar) {
+	int firstLine = scrollBar->value();
+	int lineCount = getLinesInViewport(listWidget);
+
+	return {firstLine, lineCount};
+}
+
+DSPDebugger::DSPDebugger(Emulator* emulator, QWidget* parent) : emu(emulator), disassembler(CS_ARCH_ARM, CS_MODE_ARM), QWidget(parent, Qt::Window) {
+	setWindowTitle(tr("DSP debugger"));
+	resize(1000, 600);
+
+	QGridLayout* gridLayout = new QGridLayout(this);
+	QHBoxLayout* horizontalLayout = new QHBoxLayout();
+
+	// Set up the top line widgets
+	QPushButton* goToAddressButton = new QPushButton(tr("Go to address"), this);
+	QPushButton* goToPCButton = new QPushButton(tr("Go to PC"), this);
+	QCheckBox* followPCCheckBox = new QCheckBox(tr("Follow PC"), this);
+	addressInput = new QLineEdit(this);
+
+	horizontalLayout->addWidget(goToAddressButton);
+	horizontalLayout->addWidget(goToPCButton);
+	horizontalLayout->addWidget(followPCCheckBox);
+	horizontalLayout->addWidget(addressInput);
+
+	followPCCheckBox->setChecked(followPC);
+	connect(followPCCheckBox, &QCheckBox::toggled, this, [&](bool checked) { followPC = checked; });
+
+	addressInput->setPlaceholderText(tr("Address to jump to"));
+	addressInput->setMaximumWidth(150);
+
+	gridLayout->addLayout(horizontalLayout, 0, 0);
+
+	// Disassembly list on the left, scrollbar in the middle, register view on the right
+	disasmListWidget = new QListWidget(this);
+	gridLayout->addWidget(disasmListWidget, 1, 0);
+
+	verticalScrollBar = new QScrollBar(Qt::Vertical, this);
+	gridLayout->addWidget(verticalScrollBar, 1, 1);
+
+	registerTextEdit = new QPlainTextEdit(this);
+	registerTextEdit->setEnabled(true);
+	registerTextEdit->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+	registerTextEdit->setMaximumWidth(800);
+	gridLayout->addWidget(registerTextEdit, 1, 2);
+
+	// Setup overlay for when the widget is disabled
+	disabledOverlay = new DisabledWidgetOverlay(this, tr("Pause the emulator to use the DSP Debugger"));
+	disabledOverlay->resize(size());  // Fill the whole screen
+	disabledOverlay->raise();
+	disabledOverlay->hide();
+
+	// Use a monospace font for the disassembly to align it
+	QFont mono_font = QFont("Courier New");
+	mono_font.setStyleHint(QFont::Monospace);
+	disasmListWidget->setFont(mono_font);
+	registerTextEdit->setFont(mono_font);
+
+	// Forward scrolling from the list widget to our scrollbar
+	disasmListWidget->installEventFilter(this);
+
+	// Annoyingly, due to a Qt limitation we can't set it to U32_MAX
+	verticalScrollBar->setRange(0, std::numeric_limits<s32>::max());
+	verticalScrollBar->setSingleStep(8);
+	verticalScrollBar->setPageStep(getLinesInViewport(disasmListWidget));
+	verticalScrollBar->show();
+	connect(verticalScrollBar, &QScrollBar::valueChanged, this, &DSPDebugger::updateDisasm);
+	registerTextEdit->setReadOnly(true);
+
+	connect(goToPCButton, &QPushButton::clicked, this, [&]() { scrollToPC(); });
+
+	// We have a QTimer that triggers every 500ms to update our widget when it's active
+	updateTimer = new QTimer(this);
+	connect(updateTimer, &QTimer::timeout, this, &DSPDebugger::update);
+
+	// Go to address when the "Go to address" button is pressed, or when we press enter inside the address input box
+	connect(goToAddressButton, &QPushButton::clicked, this, [&]() {
+		QString text = addressInput->text().trimmed();
+
+		bool validAddr = false;
+		u32 addr = text.toUInt(&validAddr, 16);  // Parse address as hex
+		if (validAddr) {
+			verticalScrollBar->setValue(addr);
+		} else {
+			addressInput->setText(tr("Invalid hexadecimal address"));
+		}
+	});
+	connect(addressInput, &QLineEdit::returnPressed, goToAddressButton, &QPushButton::click);
+
+	disable();
+	hide();
+}
+
+void DSPDebugger::enable() {
+	enabled = true;
+
+	disabledOverlay->hide();
+	scrollToPC();
+
+	// Update the widget every 500ms
+	updateTimer->start(500);
+	update();
+}
+
+void DSPDebugger::disable() {
+	enabled = false;
+
+	updateTimer->stop();
+	disabledOverlay->show();
+}
+
+void DSPDebugger::update() {
+	if (enabled) {
+		if (followPC) {
+			scrollToPC();
+		}
+
+		updateDisasm();
+		updateRegisters();
+	}
+}
+
+void DSPDebugger::updateDisasm() {
+	int currentRow = disasmListWidget->currentRow();
+	disasmListWidget->clear();
+
+	auto [firstLine, lineCount] = getVisibleLineRange(disasmListWidget, verticalScrollBar);
+	const u32 startPC = (firstLine + 1) & ~1;  // Align PC to 2 bytes
+
+	auto DSP = emu->getDSP();
+	auto dspRam = DSP->getDspMemory();
+	auto readByte = [&](u32 addr) {
+		if (addr >= 256_KB) return u8(0);
+
+		return dspRam[addr];
+	};
+
+	auto readWord = [&](u32 addr) {
+		u16 lsb = u16(readByte(addr));
+		u16 msb = u16(readByte(addr + 1));
+		return u16(lsb | (msb << 8));
+	};
+
+	auto& mem = emu->getMemory();
+	u32 pc = DSP->getPC();
+
+	std::string disassembly;
+
+	for (u32 addr = startPC, instructionCount = 0; instructionCount < lineCount; instructionCount++) {
+		const u16 instruction = readWord(addr);
+		const bool needExpansion = Teakra::Disassembler::NeedExpansion(instruction);
+
+		const u16 expansion = needExpansion ? readWord(addr + 2) : u16(0);
+		addr += needExpansion ? sizeof(u32) : sizeof(u16);
+
+		std::string disassembly = Teakra::Disassembler::Do(instruction, expansion);
+		disassembly = fmt::format("{:08X}     |     {}", addr, disassembly);
+
+		QListWidgetItem* item = new QListWidgetItem(QString::fromStdString(disassembly));
+		if (addr == pc) {
+			item->setBackground(Qt::darkGreen);
+		}
+		disasmListWidget->addItem(item);
+	}
+
+	disasmListWidget->setCurrentRow(currentRow);
+}
+
+void DSPDebugger::scrollToPC() {
+	u32 pc = emu->getDSP()->getPC();
+	verticalScrollBar->setValue(pc);
+}
+
+void DSPDebugger::updateRegisters() { registerTextEdit->setPlainText(QString::fromStdString("")); }
+
+bool DSPDebugger::eventFilter(QObject* obj, QEvent* event) {
+	// Forward scroll events from the list widget to the scrollbar
+	if (obj == disasmListWidget && event->type() == QEvent::Wheel) {
+		QWheelEvent* wheelEvent = (QWheelEvent*)event;
+
+		int wheelSteps = wheelEvent->angleDelta().y() / 60;
+		int newScrollValue = verticalScrollBar->value() - wheelSteps;
+		newScrollValue = qBound(verticalScrollBar->minimum(), newScrollValue, verticalScrollBar->maximum());
+		verticalScrollBar->setValue(newScrollValue);
+
+		return true;
+	}
+
+	return QWidget::eventFilter(obj, event);
+}
+
+void DSPDebugger::showEvent(QShowEvent* event) {
+	QWidget::showEvent(event);
+
+	enable();
+}
+
+// Scroll 1 instruction up or down when the arrow keys are pressed and we're at the edge of the disassembly list
+void DSPDebugger::keyPressEvent(QKeyEvent* event) {
+	constexpr usize instructionSize = sizeof(u16);
+
+	if (event->key() == Qt::Key_Up) {
+		verticalScrollBar->setValue(verticalScrollBar->value() - instructionSize);
+	} else if (event->key() == Qt::Key_Down) {
+		verticalScrollBar->setValue(verticalScrollBar->value() + instructionSize);
+	} else {
+		QWidget::keyPressEvent(event);
+	}
+}
+
+void DSPDebugger::resizeEvent(QResizeEvent* event) {
+	QWidget::resizeEvent(event);
+	disabledOverlay->resize(event->size());
+	verticalScrollBar->setPageStep(getLinesInViewport(disasmListWidget));
+
+	update();
+}