Implement byte generation for "for statement"

2 files changed, 64 insertions, 12 deletions

diff --git a/JSImpl/src/ByteCodeGenerator.cpp b/JSImpl/src/ByteCodeGenerator.cpp
index 385284d..fefed78 100644
--- a/JSImpl/src/ByteCodeGenerator.cpp
+++ b/JSImpl/src/ByteCodeGenerator.cpp
@@ -19,11 +19,12 @@ public:
 	virtual void Visit(IdentifierExpression* e) override;

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

 	virtual void Visit(IfStatement* e) override;

+	virtual void Visit(ForStatement* e) override;

 

 	IPLString GetCode();

 	unsigned ResolveRegisterName(IPLString& name);

-private:

 

+private:

 	struct Instruction

 	{

 		enum Type : char

@@ -72,12 +73,50 @@ private:
 		IPLString Args[3];

 		double Number;

 	};

+	size_t PushInstruction(Instruction::Type opcode, IPLString& arg1, IPLString& arg2, IPLString& arg3);

+	size_t PushInstruction(Instruction::Type opcode, size_t Address);

+	size_t PushInstruction(Instruction::Type opcode, IPLString& arg1, size_t Address);

+

+private:

 	IPLVector<IPLString> m_RegisterTable;

 	IPLVector<Instruction> m_Code;

 

 	IPLStack<IPLString> m_RegisterStack;

 	unsigned m_CurrentStackPointer;

	IPLString m_OutputCode;
};

 

+size_t ByteCodeGenerator::PushInstruction(Instruction::Type opcode, IPLString& arg0, IPLString& arg1, IPLString& arg2)

+{

+	Instruction ins;

+	ins.Descriptor = opcode;

+	ins.Args[0] = arg0;

+	ins.Args[1] = arg1;

+	ins.Args[2] = arg2;

+	auto address = m_Code.size();

+	m_Code.push_back(ins);

+	return address;

+}

+

+size_t ByteCodeGenerator::PushInstruction(Instruction::Type opcode, size_t Address)

+{

+	Instruction ins;

+	ins.Descriptor = opcode;

+	ins.Number = (double)Address;

+	auto address = m_Code.size();

+	m_Code.push_back(ins);

+	return address;

+}

+

+size_t ByteCodeGenerator::PushInstruction(Instruction::Type opcode, IPLString& arg0, size_t Address)

+{

+	Instruction ins;

+	ins.Descriptor = opcode;

+	ins.Args[0] = arg0;

+	ins.Number = (double)Address;

+	auto address = m_Code.size();

+	m_Code.push_back(ins);

+	return address;

+}

+

 void ByteCodeGenerator::Visit(FunctionDeclaration* e)

 {

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

@@ -122,6 +161,14 @@ void ByteCodeGenerator::Visit(TopStatements* e)
 

 void ByteCodeGenerator::Visit(VariableDefinitionExpression* e)

 {

+	auto it = std::find_if(m_RegisterTable.begin(), m_RegisterTable.end(), [&](IPLString& current) {

+		return e->GetName() == current;

+	});

+	if (it != m_RegisterTable.end())

+	{

+		// TODO: error double definitions

+		return;

+	}

 	m_RegisterTable.push_back(e->GetName());

 	if (e->GetValue())

 	{

@@ -225,9 +272,20 @@ void ByteCodeGenerator::Visit(IfStatement* e)
 	else

 	{

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

-

 	}

+}

 

+void ByteCodeGenerator::Visit(ForStatement* e)

+{

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

+	auto compareAddress = m_Code.size();

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

+	auto endAddress = PushInstruction(Instruction::Type::JMPF, m_RegisterStack.top(), 0);

+	m_RegisterStack.pop();

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

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

+	PushInstruction(Instruction::Type::JMP, compareAddress);

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

 }

 

 void ByteCodeGenerator::Visit(IdentifierExpression* e)

@@ -237,18 +295,12 @@ void ByteCodeGenerator::Visit(IdentifierExpression* e)
 

 void ByteCodeGenerator::Visit(LiteralNumber* e)

 {

-	Instruction current;

-

 	IPLString regName = IPLString("const");

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

 	m_RegisterTable.push_back(regName);

 	m_RegisterStack.push(regName);

 

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

-	current.Args[0] = regName;

-	current.Number = e->GetValue();

-

-	m_Code.push_back(current);

+	PushInstruction(Instruction::Type::CONST, regName, (size_t)e->GetValue());

 }

 

 unsigned ByteCodeGenerator::ResolveRegisterName(IPLString& name)

@@ -433,7 +485,7 @@ IPLString ByteCodeGenerator::GetCode()
 		}

 		++programCounter;

 	}

-

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

 	result += "halt\n";

 	return result;

 }

diff --git a/JSImpl/src/main.cpp b/JSImpl/src/main.cpp
index b2fb83d..c15458e 100644
--- a/JSImpl/src/main.cpp
+++ b/JSImpl/src/main.cpp
@@ -67,8 +67,8 @@ void Generate()
 {
 	IPLVector<Token> tokens;
 	//Tokenize("var a = 0;  var b = a + 123;a+b;", tokens);
-	Tokenize("var a; if(a < 4) { a = 8;} else { a = 2} ", tokens);
-
+	/*Tokenize("var a; if(a < 4) { a = 8; if(a < 7) {var b = 4;}} else { a = 2} ", tokens);*/
+	Tokenize("var i = 0; for (var j = 0; j < 10; j = j + 1) { i = i + j; }", tokens);
 	std::cout << GenerateByteCode(Parse(tokens));
 }