assembling first version

This commit is contained in:
zanostro 2025-12-14 13:09:14 +01:00
parent 9e9039af05
commit d3e08abd30
7 changed files with 896 additions and 1 deletions

View file

@ -6,6 +6,8 @@
#include "../../include/opcode.h" #include "../../include/opcode.h"
#include "../../include/constants.h" #include "../../include/constants.h"
#include "../../include/loader.h" #include "../../include/loader.h"
#include "../../include/parser.h"
#include "../../include/code.h"
#include <QIntValidator> #include <QIntValidator>
#include <QLineEdit> #include <QLineEdit>
@ -20,6 +22,9 @@
#include <QFileDialog> #include <QFileDialog>
#include <QMessageBox> #include <QMessageBox>
#include <QScrollBar> #include <QScrollBar>
#include <QDir>
#include <fstream>
#include <sstream>
class Loader; class Loader;
@ -102,6 +107,7 @@ MainWindow::MainWindow(QWidget *parent) :
// Connect menu actions // Connect menu actions
connect(ui->actionLoad_Object_File, &QAction::triggered, this, &MainWindow::loadObjectFile); connect(ui->actionLoad_Object_File, &QAction::triggered, this, &MainWindow::loadObjectFile);
connect(ui->actionLoad_Asm_file, &QAction::triggered, this, &MainWindow::loadAsmFile);
connect(ui->actionAbout, &QAction::triggered, this, &MainWindow::showAboutDialog); connect(ui->actionAbout, &QAction::triggered, this, &MainWindow::showAboutDialog);
connect(ui->actionFrequency, &QAction::triggered, this, &MainWindow::showFrequencyDialog); connect(ui->actionFrequency, &QAction::triggered, this, &MainWindow::showFrequencyDialog);
@ -981,6 +987,100 @@ void MainWindow::loadObjectFile()
} }
} }
void MainWindow::loadAsmFile()
{
QString fileName = QFileDialog::getOpenFileName(this,
tr("Load Assembly File"),
QString(),
tr("Assembly Files (*.asm);;All Files (*)"));
if (fileName.isEmpty()) {
return;
}
try {
// Stop execution if running
m_controller->stop();
// Reset machine state
m_machine->reset();
// Read assembly file
std::ifstream file(fileName.toStdString());
if (!file.is_open()) {
throw std::runtime_error("Could not open file: " + fileName.toStdString());
}
std::string source((std::istreambuf_iterator<char>(file)),
std::istreambuf_iterator<char>());
file.close();
// Parse and assemble
Parser parser;
Code code = parser.parse(source);
code.assemble();
// Generate object code
std::string objCode = code.emitText();
// Create resources directory if it doesn't exist
QDir dir;
if (!dir.exists("resources")) {
dir.mkpath("resources");
}
// Save object file to resources directory
QFileInfo fileInfo(fileName);
QString objFileName = "resources/" + fileInfo.completeBaseName() + ".obj";
std::ofstream objFile(objFileName.toStdString());
if (!objFile.is_open()) {
throw std::runtime_error("Could not create object file: " + objFileName.toStdString());
}
objFile << objCode;
objFile.close();
// Generate and save log file
QString logFileName = "resources/" + fileInfo.completeBaseName() + ".log";
std::ofstream logFile(logFileName.toStdString());
if (!logFile.is_open()) {
throw std::runtime_error("Could not create log file: " + logFileName.toStdString());
}
logFile << "=== SIC/XE Assembler Log ===\n\n";
logFile << "Source file: " << fileName.toStdString() << "\n";
logFile << "Object file: " << objFileName.toStdString() << "\n\n";
logFile << "=== Symbols ===\n";
logFile << code.dumpSymbols() << "\n\n";
logFile << "=== Code ===\n";
logFile << code.dumpCode() << "\n\n";
logFile << "=== Object Code ===\n";
logFile << objCode << "\n";
logFile.close();
// Load the generated object file
Loader loader(m_machine, objFileName.toStdString());
loader.load();
// Update displays
updateRegisterDisplays();
updateMemoryDisplay();
updateDisassemblyDisplay();
QMessageBox::information(this, tr("Success"),
tr("Assembly successful!\nObject file: %1\nLog file: %2")
.arg(objFileName).arg(logFileName));
} catch (const std::exception &e) {
QMessageBox::critical(this, tr("Error"),
tr("Failed to assemble file: %1").arg(e.what()));
}
}
void MainWindow::showAboutDialog() void MainWindow::showAboutDialog()
{ {
QMessageBox::about(this, tr("About SIC/XE Simulator"), QMessageBox::about(this, tr("About SIC/XE Simulator"),

View file

@ -51,6 +51,7 @@ private slots:
void onDisassemblyGoToStart(); void onDisassemblyGoToStart();
void onDisassemblyGoToEnd(); void onDisassemblyGoToEnd();
void loadObjectFile(); void loadObjectFile();
void loadAsmFile();
void showAboutDialog(); void showAboutDialog();
void showFrequencyDialog(); void showFrequencyDialog();

View file

@ -892,6 +892,7 @@
<string>File</string> <string>File</string>
</property> </property>
<addaction name="actionLoad_Object_File"/> <addaction name="actionLoad_Object_File"/>
<addaction name="actionLoad_Asm_file"/>
</widget> </widget>
<widget class="QMenu" name="menuMachine"> <widget class="QMenu" name="menuMachine">
<property name="title"> <property name="title">
@ -924,6 +925,11 @@
<string>About</string> <string>About</string>
</property> </property>
</action> </action>
<action name="actionLoad_Asm_file">
<property name="text">
<string>Load Asm file</string>
</property>
</action>
</widget> </widget>
<resources/> <resources/>
<connections/> <connections/>

View file

@ -3,6 +3,8 @@
#include <vector> #include <vector>
#include <memory> #include <memory>
#include <unordered_map>
#include <cstdint>
#include "node.h" #include "node.h"
@ -17,8 +19,42 @@ public:
const string toString() const; const string toString() const;
// Two-pass assembler methods
void assemble();
std::vector<uint8_t> emitCode();
std::string emitText();
std::string dumpSymbols() const;
std::string dumpCode() const;
private: private:
std::vector<std::shared_ptr<Node>> _lines; std::vector<std::shared_ptr<Node>> _lines;
// Assembler state
std::unordered_map<std::string, int> _symbolTable;
std::vector<int> _locationCounters; // Location counter per line
int _startAddress = 0;
int _programLength = 0;
std::string _programName;
int _baseRegister = -1; // -1 means not set
// Pass 1: build symbol table and assign addresses
void firstPass();
// Pass 2: generate code
void secondPass();
// Helper methods
int getInstructionLength(const std::shared_ptr<Node>& node, int locationCounter) const;
std::vector<uint8_t> generateInstruction(const InstructionNode* inst, int address);
std::vector<uint8_t> generateData(const DataNode* data);
// Addressing mode selection
struct AddressingResult {
int nixbpe; // ni, x, b, p, e bits
int displacement; // 12-bit or 20-bit
bool success;
};
AddressingResult selectAddressingMode(int targetAddress, int pc, bool indexed, bool immediate, bool indirect, bool extended) const;
}; };

View file

@ -0,0 +1,223 @@
prog START 0
.-------------------------------------------
. MAIN LOOP
.
. Psevdo:
. sp = 0
. while true:
. n = readFA()
. if n == 0: halt
. acc = 1
. fact() ; rekurzivno: acc = n!
. printStdout(acc)
.-------------------------------------------
CLEAR A
STA sp
loop JSUB readFA
COMP #0
JEQ halt
STA n
LDA #1
STA acc
JSUB fact
LDA acc
JSUB printStdout
J loop
halt J halt
.-------------------------------------------
. readFA
.
. Psevdo:
. B = 0
. while true:
. ch = RD(FA)
. if ch == CR or ch == LF: break
. digit = ch - '0'
. B = B * 10 + digit
. return B
.-------------------------------------------
readFA CLEAR B
LDS #10
rd_loopFA RD #0xFA
COMP #0x0D . CR?
JEQ rd_doneCR_FA
COMP #0x0A . LF?
JEQ rd_doneFA
SUB #0x30
MULR S,B . B = B * 10
ADDR A,B . B = B + digit
J rd_loopFA
rd_doneCR_FA RD #0xFA . pogoltni LF po CR
rd_doneFA CLEAR A
RMO B,A
RSUB
.-------------------------------------------
. fact
.
. Psevdo (globalni n, acc, sklad L):
. fact():
. push(L)
. if n <= 1:
. pop(L); return
. acc = acc * n
. n = n - 1
. fact()
. pop(L); return
.-------------------------------------------
fact . push L
LDA sp
ADD #3
STA sp
LDX sp
STL stackL,X
LDA n
COMP #1
JGT fact_rec
. base case: n <= 1
LDX sp
LDL stackL,X
LDA sp
SUB #3
STA sp
RSUB
fact_rec . recursive case: acc *= n; n--; fact()
LDB acc
LDS n
MULR S,B
STB acc
LDA n
SUB #1
STA n
JSUB fact
. pop L in return to caller
LDX sp
LDL stackL,X
LDA sp
SUB #3
STA sp
RSUB
.-------------------------------------------
. printStdout
.
. Psevdo:
. if A == 0:
. print "0\n"
. return
. ps_val = A
. ps_len = 0
. while ps_val > 0:
. q = ps_val / 10
. r = ps_val % 10
. buf[ps_len] = '0' + r
. ps_len++
. ps_val = q
. for i = ps_len-1 .. 0:
. print buf[i]
. print "\r\n"
.-------------------------------------------
printStdout COMP #0
JEQ ps_zero
STA ps_val
LDA #0
STA ps_len
LDS #10
LDT #0x30 . '0'
ps_div LDA ps_val
COMP #0
JEQ ps_divdone
RMO A,B
DIVR S,B . kvocient v B
RMO B,X . X = kvocient
MULR S,B
SUBR B,A . A = ostanek
ADDR T,A . A = '0' + ostanek
STA psdigit
LDA ps_len
STA ps_idx
LDA #psbuf
ADD ps_idx
STA ps_ptr
LDA psdigit
STCH @ps_ptr
LDA ps_len
ADD #1
STA ps_len
RMO X,A
STA ps_val
J ps_div
ps_divdone LDA ps_len
SUB #1
STA ps_idx
ps_print LDA ps_idx
COMP #0
JLT ps_end
LDA #psbuf
ADD ps_idx
STA ps_ptr
LDCH @ps_ptr
WD #1
LDA ps_idx
SUB #1
STA ps_idx
J ps_print
ps_end LDA #0x0D . CR
WD #1
LDA #0x0A . LF
WD #1
RSUB
ps_zero LDA #0x30 . "0"
WD #1
LDA #0x0D
WD #1
LDA #0x0A
WD #1
RSUB
.data
. rekurzija faktoriala
sp WORD 0 . stack pointer
n WORD 0
acc WORD 0 . akumulator za faktorial
stackL RESB 60
. printStdout
ps_val WORD 0
ps_len WORD 0
ps_idx WORD 0
psdigit WORD 0
ps_ptr WORD 0
psbuf RESB 12
END prog

View file

@ -1,4 +1,10 @@
#include "code.h" #include "code.h"
#include "opcode.h"
#include "constants.h"
#include <sstream>
#include <iomanip>
#include <stdexcept>
#include <cstring>
void Code::addLine(const std::shared_ptr<Node> &line) void Code::addLine(const std::shared_ptr<Node> &line)
{ {
@ -18,3 +24,510 @@ const string Code::toString() const
} }
return result; return result;
} }
// ============================================================
// TWO-PASS ASSEMBLER IMPLEMENTATION
// ============================================================
void Code::assemble() {
firstPass();
secondPass();
}
void Code::firstPass() {
_symbolTable.clear();
_locationCounters.clear();
_locationCounters.resize(_lines.size(), 0);
int locationCounter = 0;
bool startFound = false;
for (size_t i = 0; i < _lines.size(); ++i) {
auto& line = _lines[i];
_locationCounters[i] = locationCounter;
// Handle label
std::string label = line->getLabel();
if (!label.empty()) {
if (_symbolTable.find(label) != _symbolTable.end()) {
throw std::runtime_error("Duplicate symbol: " + label);
}
_symbolTable[label] = locationCounter;
}
// Check for directives
if (auto* directive = dynamic_cast<DirectiveNode*>(line.get())) {
switch (directive->kind()) {
case DirectiveKind::START: {
if (std::holds_alternative<int>(directive->arg())) {
_startAddress = std::get<int>(directive->arg());
locationCounter = _startAddress;
_locationCounters[i] = locationCounter;
if (!label.empty()) {
_symbolTable[label] = locationCounter;
_programName = label;
}
startFound = true;
}
break;
}
case DirectiveKind::END:
_programLength = locationCounter - _startAddress;
break;
case DirectiveKind::BASE: {
// BASE sets base register for addressing
if (std::holds_alternative<std::string>(directive->arg())) {
// Will resolve in second pass
}
break;
}
case DirectiveKind::NOBASE:
_baseRegister = -1;
break;
case DirectiveKind::EQU: {
// EQU defines symbol value
if (!label.empty() && std::holds_alternative<int>(directive->arg())) {
_symbolTable[label] = std::get<int>(directive->arg());
}
break;
}
case DirectiveKind::ORG: {
// ORG changes location counter
if (std::holds_alternative<int>(directive->arg())) {
locationCounter = std::get<int>(directive->arg());
}
break;
}
default:
break;
}
continue;
}
// Handle data directives
if (auto* data = dynamic_cast<DataNode*>(line.get())) {
int length = 0;
switch (data->kind()) {
case DataKind::WORD:
length = 3; // 24-bit word
break;
case DataKind::BYTE: {
if (std::holds_alternative<std::vector<uint8_t>>(data->value())) {
length = std::get<std::vector<uint8_t>>(data->value()).size();
}
break;
}
case DataKind::RESW: {
if (std::holds_alternative<int>(data->value())) {
length = std::get<int>(data->value()) * 3;
}
break;
}
case DataKind::RESB: {
if (std::holds_alternative<int>(data->value())) {
length = std::get<int>(data->value());
}
break;
}
}
locationCounter += length;
continue;
}
// Handle instructions
if (auto* inst = dynamic_cast<InstructionNode*>(line.get())) {
int length = getInstructionLength(line, locationCounter);
locationCounter += length;
}
}
if (!startFound) {
_startAddress = 0;
}
_programLength = locationCounter - _startAddress;
}
int Code::getInstructionLength(const std::shared_ptr<Node>& node, int locationCounter) const {
auto* inst = dynamic_cast<InstructionNode*>(node.get());
if (!inst || !inst->getMnemonic()) {
return 0;
}
auto mnemonic = inst->getMnemonic();
InstructionType type = mnemonic->type();
switch (type) {
case InstructionType::TYPE1:
return 1;
case InstructionType::TYPE2:
return 2;
case InstructionType::TYPE3_4:
return mnemonic->extended() ? 4 : 3;
default:
return 0;
}
}
void Code::secondPass() {
// Generate code for all instructions and data
// This will be used by emitCode() and emitText()
}
std::vector<uint8_t> Code::emitCode() {
std::vector<uint8_t> code;
code.resize(_programLength, 0);
for (size_t i = 0; i < _lines.size(); ++i) {
auto& line = _lines[i];
int address = _locationCounters[i];
int offset = address - _startAddress;
if (offset < 0 || offset >= _programLength) {
continue;
}
// Generate instruction
if (auto* inst = dynamic_cast<InstructionNode*>(line.get())) {
auto bytes = generateInstruction(inst, address);
for (size_t j = 0; j < bytes.size() && (offset + j) < code.size(); ++j) {
code[offset + j] = bytes[j];
}
}
// Generate data
if (auto* data = dynamic_cast<DataNode*>(line.get())) {
auto bytes = generateData(data);
for (size_t j = 0; j < bytes.size() && (offset + j) < code.size(); ++j) {
code[offset + j] = bytes[j];
}
}
}
return code;
}
std::vector<uint8_t> Code::generateInstruction(const InstructionNode* inst, int address) {
std::vector<uint8_t> bytes;
if (!inst || !inst->getMnemonic()) {
return bytes;
}
auto mnemonic = inst->getMnemonic();
uint8_t opcode = mnemonic->opcode();
InstructionType type = mnemonic->type();
bool extended = mnemonic->extended();
const auto& operands = mnemonic->operands();
switch (type) {
case InstructionType::TYPE1: {
bytes.push_back(opcode);
break;
}
case InstructionType::TYPE2: {
bytes.push_back(opcode);
uint8_t r1 = 0, r2 = 0;
if (operands.size() >= 1 && std::holds_alternative<Register>(operands[0])) {
r1 = std::get<Register>(operands[0]).num & 0xF;
}
if (operands.size() >= 2 && std::holds_alternative<Register>(operands[1])) {
r2 = std::get<Register>(operands[1]).num & 0xF;
}
bytes.push_back((r1 << 4) | r2);
break;
}
case InstructionType::TYPE3_4: {
// Format 3 or 4 instruction
int ni = 0, x = 0, b = 0, p = 0, e = 0;
int targetAddress = 0;
bool immediate = false, indirect = false, indexed = false;
// Parse operand
if (!operands.empty()) {
if (std::holds_alternative<Immediate>(operands[0])) {
immediate = true;
targetAddress = std::get<Immediate>(operands[0]).value;
ni = 0x01; // n=0, i=1
} else if (std::holds_alternative<SymbolRef>(operands[0])) {
auto& sym = std::get<SymbolRef>(operands[0]);
immediate = sym.immediate;
indirect = sym.indirect;
indexed = sym.indexed;
// Look up symbol
auto it = _symbolTable.find(sym.name);
if (it != _symbolTable.end()) {
targetAddress = it->second;
}
// Set ni bits
if (immediate) {
ni = 0x01; // n=0, i=1
} else if (indirect) {
ni = 0x02; // n=1, i=0
} else {
ni = 0x03; // n=1, i=1 (simple/direct)
}
}
} else {
// No operand (like RSUB)
ni = 0x03;
}
if (indexed) {
x = 1;
}
if (extended) {
e = 1;
}
// Calculate PC for addressing
int pc = address + (extended ? 4 : 3);
// Select addressing mode
auto result = selectAddressingMode(targetAddress, pc, indexed, immediate, indirect, extended);
if (result.success) {
b = (result.nixbpe >> 2) & 1;
p = (result.nixbpe >> 1) & 1;
e = result.nixbpe & 1;
}
int displacement = result.displacement;
// Build instruction bytes
uint8_t byte1 = (opcode & 0xFC) | ni;
uint8_t byte2 = (x << 7) | (b << 6) | (p << 5) | (e << 4);
bytes.push_back(byte1);
if (extended) {
// Format 4: 20-bit address
byte2 |= (displacement >> 16) & 0x0F;
bytes.push_back(byte2);
bytes.push_back((displacement >> 8) & 0xFF);
bytes.push_back(displacement & 0xFF);
} else {
// Format 3: 12-bit displacement
byte2 |= (displacement >> 8) & 0x0F;
bytes.push_back(byte2);
bytes.push_back(displacement & 0xFF);
}
break;
}
default:
break;
}
return bytes;
}
Code::AddressingResult Code::selectAddressingMode(int targetAddress, int pc, bool indexed, bool immediate, bool indirect, bool extended) const {
AddressingResult result;
result.success = false;
result.nixbpe = 0;
result.displacement = 0;
// Immediate mode - use target address directly
if (immediate) {
if (extended) {
result.nixbpe = 0x01; // e=1, b=0, p=0
result.displacement = targetAddress & 0xFFFFF; // 20 bits
} else {
result.nixbpe = 0x00; // e=0, b=0, p=0
result.displacement = targetAddress & 0xFFF; // 12 bits
}
result.success = true;
return result;
}
// Extended format - use absolute address
if (extended) {
result.nixbpe = 0x01; // e=1, b=0, p=0
result.displacement = targetAddress & 0xFFFFF;
result.success = true;
return result;
}
// Try PC-relative (-2048 to +2047)
int pcDisp = targetAddress - pc;
if (pcDisp >= -2048 && pcDisp <= 2047) {
result.nixbpe = 0x02; // p=1, b=0, e=0
result.displacement = pcDisp & 0xFFF;
result.success = true;
return result;
}
// Try base-relative (0 to 4095)
if (_baseRegister >= 0) {
int baseDisp = targetAddress - _baseRegister;
if (baseDisp >= 0 && baseDisp <= 4095) {
result.nixbpe = 0x04; // b=1, p=0, e=0
result.displacement = baseDisp & 0xFFF;
result.success = true;
return result;
}
}
// Try direct (0 to 4095)
if (targetAddress >= 0 && targetAddress <= 4095) {
result.nixbpe = 0x00; // b=0, p=0, e=0
result.displacement = targetAddress & 0xFFF;
result.success = true;
return result;
}
// Try SIC format (0 to 32767, 15 bits)
if (targetAddress >= 0 && targetAddress <= 32767) {
result.nixbpe = 0x00;
result.displacement = targetAddress & 0x7FFF;
result.success = true;
return result;
}
// Could not find suitable addressing mode
result.success = false;
return result;
}
std::vector<uint8_t> Code::generateData(const DataNode* data) {
std::vector<uint8_t> bytes;
if (!data) {
return bytes;
}
switch (data->kind()) {
case DataKind::WORD: {
if (std::holds_alternative<int>(data->value())) {
int value = std::get<int>(data->value()) & 0xFFFFFF;
// SIC/XE stores words in big-endian (MSB first)
bytes.push_back((value >> 16) & 0xFF);
bytes.push_back((value >> 8) & 0xFF);
bytes.push_back(value & 0xFF);
}
break;
}
case DataKind::BYTE: {
if (std::holds_alternative<std::vector<uint8_t>>(data->value())) {
bytes = std::get<std::vector<uint8_t>>(data->value());
}
break;
}
case DataKind::RESW:
case DataKind::RESB:
// Reserved space - emit zeros (handled by initialized array)
break;
}
return bytes;
}
std::string Code::emitText() {
std::ostringstream oss;
// H record: program name, start address, length
oss << "H ";
std::string name = _programName.empty() ? "PROG" : _programName;
name.resize(6, ' ');
oss << name << " ";
oss << std::setfill('0') << std::setw(6) << std::hex << std::uppercase << _startAddress << " ";
oss << std::setfill('0') << std::setw(6) << std::hex << std::uppercase << _programLength;
oss << "\n";
// T records: text (code/data)
std::vector<uint8_t> code = emitCode();
int textStart = 0;
while (textStart < code.size()) {
int textLength = std::min(30, (int)code.size() - textStart);
// Skip all-zero sections for RESW/RESB
bool allZeros = true;
for (int i = 0; i < textLength; ++i) {
if (code[textStart + i] != 0) {
allZeros = false;
break;
}
}
if (!allZeros) {
oss << "T ";
oss << std::setfill('0') << std::setw(6) << std::hex << std::uppercase << (_startAddress + textStart) << " ";
oss << std::setfill('0') << std::setw(2) << std::hex << std::uppercase << textLength << " ";
for (int i = 0; i < textLength; ++i) {
oss << std::setfill('0') << std::setw(2) << std::hex << std::uppercase << (int)code[textStart + i];
}
oss << "\n";
}
textStart += textLength;
}
// E record: execution start address
oss << "E ";
oss << std::setfill('0') << std::setw(6) << std::hex << std::uppercase << _startAddress;
oss << "\n";
return oss.str();
}
std::string Code::dumpSymbols() const {
std::ostringstream oss;
oss << "=== Symbol Table ===\n";
oss << std::left << std::setw(20) << "Symbol" << "Address\n";
oss << std::string(30, '-') << "\n";
for (const auto& [symbol, address] : _symbolTable) {
oss << std::left << std::setw(20) << symbol;
oss << std::hex << std::uppercase << std::setw(6) << std::setfill('0') << address << "\n";
}
return oss.str();
}
std::string Code::dumpCode() const {
std::ostringstream oss;
oss << "=== Code Listing ===\n";
oss << std::hex << std::uppercase << std::setfill('0');
std::vector<uint8_t> code = const_cast<Code*>(this)->emitCode();
for (size_t i = 0; i < _lines.size(); ++i) {
auto& line = _lines[i];
int address = _locationCounters[i];
int offset = address - _startAddress;
// Print address
oss << std::setw(6) << address << " ";
// Print generated bytes
int length = getInstructionLength(line, address);
if (auto* data = dynamic_cast<DataNode*>(line.get())) {
auto bytes = const_cast<Code*>(this)->generateData(data);
length = bytes.size();
}
for (int j = 0; j < length && (offset + j) < code.size(); ++j) {
oss << std::setw(2) << (int)code[offset + j];
}
// Pad for alignment
for (int j = length; j < 12; ++j) {
oss << " ";
}
oss << " " << line->toString() << "\n";
}
return oss.str();
}

View file

@ -390,6 +390,18 @@ std::shared_ptr<Node> Parser::parseInstruction() {
lexer_.skipWhitespace(); lexer_.skipWhitespace();
// Check for comment after label - create a label-only instruction node
if (lexer_.peek() == '.') {
std::string comment = std::string(lexer_.readTo('\n'));
// Return an instruction node with just the label (null mnemonic)
auto node = std::make_shared<InstructionNode>(
std::move(label),
nullptr,
std::move(comment)
);
return node;
}
// Check for extended format prefix // Check for extended format prefix
bool isExtended = lexer_.peek() == '+'; bool isExtended = lexer_.peek() == '+';
if (isExtended) { if (isExtended) {
@ -399,7 +411,11 @@ std::shared_ptr<Node> Parser::parseInstruction() {
std::string name = std::string(lexer_.readAlphanumeric()); std::string name = std::string(lexer_.readAlphanumeric());
if (name.empty()) { if (name.empty()) {
throw SyntaxError("Mnemonic or directive expected", lexer_.row, lexer_.col); throw SyntaxError(
"Mnemonic or directive expected (label='" + label + "')",
lexer_.row,
lexer_.col
);
} }
// Check if it's a directive or data directive // Check if it's a directive or data directive