Implement if

1 files changed, 87 insertions, 30 deletions

diff --git a/JSImpl/src/ByteCodeGenerator.cpp b/JSImpl/src/ByteCodeGenerator.cpp
index 349c93a..385284d 100644
--- a/JSImpl/src/ByteCodeGenerator.cpp
+++ b/JSImpl/src/ByteCodeGenerator.cpp
@@ -16,6 +16,9 @@ public:
 	virtual void Visit(TopStatements* e) override;

 	virtual void Visit(ListExpression* e) override;

 	virtual void Visit(VariableDefinitionExpression* e) override;

+	virtual void Visit(IdentifierExpression* e) override;

+	virtual void Visit(EmptyExpression* e) override { (void)e; }

+	virtual void Visit(IfStatement* e) override;

 

 	IPLString GetCode();

 	unsigned ResolveRegisterName(IPLString& name);

@@ -101,19 +104,20 @@ void ByteCodeGenerator::Visit(BlockStatement* e)
 void ByteCodeGenerator::Visit(TopStatements* e)

 {

 	auto& statements = e->GetValues();

+

+	Instruction current;

+	current.Descriptor = Instruction::Type::PUSH;

+	auto index = m_Code.size();

+	m_Code.push_back(current);

 	for (auto& s : statements)

 	{

-		Instruction current;

-		current.Descriptor = Instruction::Type::PUSH;

-		auto index = m_Code.size();

-		m_Code.push_back(current);

 		s->Accept(*this);

-		m_Code[index].Number = (unsigned)m_RegisterTable.size();

-

-		current.Descriptor = Instruction::Type::POP;

-		current.Number = (unsigned)m_RegisterTable.size();

-		m_Code.push_back(current);

 	}

+	m_Code[index].Number = (unsigned)m_RegisterTable.size();

+

+	current.Descriptor = Instruction::Type::POP;

+	current.Number = (unsigned)m_RegisterTable.size();

+	m_Code.push_back(current);

 }

 

 void ByteCodeGenerator::Visit(VariableDefinitionExpression* e)

@@ -123,22 +127,20 @@ void ByteCodeGenerator::Visit(VariableDefinitionExpression* e)
 	{

 		e->GetValue()->Accept(*this);

 	}

-	Instruction current;

-	current.Descriptor = Instruction::Type::MOV;

-	current.Args[0] = e->GetName();

-	current.Args[1] = m_RegisterStack.top();

-	m_RegisterStack.pop();

-	m_Code.push_back(current);

+	if (!m_RegisterStack.empty())

+	{

+		Instruction current;

+		current.Descriptor = Instruction::Type::MOV;

+		current.Args[0] = e->GetName();

+		current.Args[1] = m_RegisterStack.top();

+		m_RegisterStack.pop();

+		m_Code.push_back(current);

+	}

 }

 

 void ByteCodeGenerator::Visit(BinaryExpression* e)

 {

 	Instruction current;

-	IPLString regName = IPLString ("tmp");

-	regName += std::to_string(m_RegisterTable.size());

-	m_RegisterTable.push_back(regName);

-	m_RegisterStack.push(regName);

-	current.Args[0] = regName;

 

 	e->GetLeft()->Accept(*this);

 	current.Args[1] = m_RegisterStack.top();

@@ -148,6 +150,22 @@ void ByteCodeGenerator::Visit(BinaryExpression* e)
 	current.Args[2] = m_RegisterStack.top();

 	m_RegisterStack.pop();

 

+	if (e->GetOperator() == TokenType::Equal)

+	{

+		current.Descriptor = Instruction::Type::MOV;

+		current.Args[0] = current.Args[1];

+		current.Args[1] = current.Args[2];

+		m_Code.push_back(current);

+		return;

+	}

+

+

+	IPLString regName = IPLString ("tmp");

+	regName += std::to_string(m_RegisterTable.size());

+	m_RegisterTable.push_back(regName);

+	m_RegisterStack.push(regName);

+	current.Args[0] = regName;

+

 	switch (e->GetOperator()) {

 	case TokenType::Plus:

 		current.Descriptor = Instruction::Type::ADD;

@@ -171,9 +189,7 @@ void ByteCodeGenerator::Visit(BinaryExpression* e)
 		NOT_IMPLEMENTED;

 		break;

 	case TokenType::Equal:

-		current.Descriptor = Instruction::Type::MOV;

-		current.Args[0] = current.Args[1];

-		current.Args[1] = current.Args[2];

+

 	break;

 	default:

 		NOT_IMPLEMENTED;

@@ -181,6 +197,44 @@ void ByteCodeGenerator::Visit(BinaryExpression* e)
 	m_Code.push_back(current);

 }

 

+void ByteCodeGenerator::Visit(IfStatement* e)

+{

+	Instruction current;

+	e->GetCondition()->Accept(*this);

+	current.Descriptor = Instruction::Type::JMPF;

+	current.Args[0] = m_RegisterStack.top();

+	current.Number = 0.0;

+	m_RegisterStack.pop();

+	auto ifIndex = m_Code.size();

+	m_Code.push_back(current);

+

+	e->GetIfStatement()->Accept(*this);

+

+	if (e->GetElseStatement())

+	{

+		current.Descriptor = Instruction::Type::JMP;

+		m_Code.push_back(current);

+		auto afterTrueBlock = m_Code.size();

+

+		e->GetElseStatement()->Accept(*this);

+

+		// Patching

+		m_Code[ifIndex].Number = (double)afterTrueBlock;

+		m_Code[afterTrueBlock - 1].Number = (double)m_Code.size();

+	}

+	else

+	{

+		m_Code[ifIndex].Number = (double)m_Code.size();

+

+	}

+

+}

+

+void ByteCodeGenerator::Visit(IdentifierExpression* e)

+{

+	m_RegisterStack.push(e->GetName());

+}

+

 void ByteCodeGenerator::Visit(LiteralNumber* e)

 {

 	Instruction current;

@@ -208,9 +262,10 @@ unsigned ByteCodeGenerator::ResolveRegisterName(IPLString& name)
 IPLString ByteCodeGenerator::GetCode()

 {

 	IPLString result;

-

+	auto programCounter = 0;

 	for (auto& i : m_Code)

 	{

+		result += std::to_string(programCounter) + ": ";

 		switch (i.Descriptor)

 		{

 		case ByteCodeGenerator::Instruction::ADD:

@@ -259,24 +314,25 @@ IPLString ByteCodeGenerator::GetCode()
 			NOT_IMPLEMENTED;

 			break;

 		case ByteCodeGenerator::Instruction::JMP:

-			result += "jmp";

-			NOT_IMPLEMENTED;

+			result += "jmp " + std::to_string((size_t)i.Number) + '\n';

 			break;

 		case ByteCodeGenerator::Instruction::JMPT:

-			result += "jmpt r" + std::to_string(ResolveRegisterName(i.Args[0])) + '\n';

+			result += "jmpt r" + std::to_string(ResolveRegisterName(i.Args[0]))

+				+ " " + std::to_string((size_t)i.Number) + '\n';

 			break;

 		case ByteCodeGenerator::Instruction::JMPF:

-			result += "jmpf r" + std::to_string(ResolveRegisterName(i.Args[0])) + '\n';

+			result += "jmpf r" + std::to_string(ResolveRegisterName(i.Args[0]))

+				+ " " + std::to_string((size_t)i.Number) + '\n';

 			break;

 		case ByteCodeGenerator::Instruction::DUP:

 			result += "dup";

 			NOT_IMPLEMENTED;

 			break;

 		case ByteCodeGenerator::Instruction::PUSH:

-			result += "push " + std::to_string((unsigned)i.Number) + '\n';

+			result += "push " + std::to_string((size_t)i.Number) + '\n';

 			break;

 		case ByteCodeGenerator::Instruction::POP:

-			result += "pop " + std::to_string((unsigned)i.Number) + '\n';

+			result += "pop " + std::to_string((size_t)i.Number) + '\n';

 			break;

 		case ByteCodeGenerator::Instruction::SAVE:

 			result += "save";

@@ -375,6 +431,7 @@ IPLString ByteCodeGenerator::GetCode()
 			break;

 			

 		}

+		++programCounter;

 	}

 

 	result += "halt\n";