From 6ba49b30cf1e33fb0dd6782a404ec34b7964cb59 Mon Sep 17 00:00:00 2001
From: Martin Dobrev <martindobrev0@gmail.com>
Date: Tue, 24 Nov 2020 18:06:26 +0200
Subject: Feature/object getters (#101)

* Add member access expression.

* Implement property getters.

* Add test for property getters.

* Add test for property setter.

* Implement while and do-while

Signed-off-by: Martin Dobrev <martindobrev0@gmail.com>

* Add implement byte code generation for break/continue in for/while.
---
 JSImpl/src/ByteCodeGenerator.cpp | 119 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)

(limited to 'JSImpl/src/ByteCodeGenerator.cpp')

diff --git a/JSImpl/src/ByteCodeGenerator.cpp b/JSImpl/src/ByteCodeGenerator.cpp
index 31a80bd..4d5cb09 100644
--- a/JSImpl/src/ByteCodeGenerator.cpp
+++ b/JSImpl/src/ByteCodeGenerator.cpp
@@ -22,10 +22,15 @@ public:
 	virtual void Visit(EmptyExpression* e) override { (void)e; }
 	virtual void Visit(IfStatement* e) override;
 	virtual void Visit(ForStatement* e) override;
+	virtual void Visit(WhileStatement* e) override;
+	virtual void Visit(Break* e) override;
+	virtual void Visit(Continue* e) override;
 	virtual void Visit(UnaryExpression* e) override;
 	virtual void Visit(LiteralField* e) override;
 	virtual void Visit(LiteralObject* e) override;
 	virtual void Visit(LiteralString* e) override;
+	virtual void Visit(MemberAccess* e) override;
+	virtual void Visit(Call* e) override;
 
 	IPLString GetCode();
 	unsigned ResolveRegisterName(IPLString& name);
@@ -101,16 +106,62 @@ private:
 	void PushConst(double c);
 	IPLString CreateRegister();
 	bool CheckOpCode(int opcode) { return opcode >= Instruction::Type::FIRST && opcode <= Instruction::Type::LAST; }
+
+	void OpenBreakScope() { m_BreakScopeStack.push(IPLVector<size_t>()); };
+	void OpenContinueScope() { m_ContinueScopeStack.push(IPLVector<size_t>()); };
+	void CloseBreakScope(size_t addr);
+	void CloseContinueScope(size_t addr);
+	void PushBreak();
+	void PushContinue();
 private:
 	IPLVector<IPLString> m_RegisterTable;
 	IPLVector<Instruction> m_Code;
 	IPLVector<IPLString> m_Source;
 
+	IPLStack<IPLVector<size_t>> m_BreakScopeStack;
+	IPLStack<IPLVector<size_t>> m_ContinueScopeStack;
+
 	IPLStack<IPLString> m_RegisterStack;
 	IPLString m_OutputCode;
 	ByteCodeGeneratorOptions m_Options;
 };
 
+void ByteCodeGenerator::PushBreak()
+{
+	assert(!m_BreakScopeStack.empty());
+	auto addr = PushInstruction(Instruction::Type::JMP, 0);
+	m_BreakScopeStack.top().push_back(addr);
+}
+
+void ByteCodeGenerator::PushContinue()
+{
+	assert(!m_ContinueScopeStack.empty());
+	auto addr = PushInstruction(Instruction::Type::JMP, 0);
+	m_ContinueScopeStack.top().push_back(addr);
+}
+
+void ByteCodeGenerator::CloseBreakScope(size_t addr)
+{
+	auto currentScope = m_BreakScopeStack.top();
+	for (const auto& br : currentScope)
+	{
+		assert(m_Code[br].Descriptor == Instruction::Type::JMP);
+		m_Code[br].Values.Address[0] = addr;
+	}
+	m_BreakScopeStack.pop();
+};
+
+void ByteCodeGenerator::CloseContinueScope(size_t addr)
+{
+	auto currentScope = m_ContinueScopeStack.top();
+	for (const auto& br : currentScope)
+	{
+		assert(m_Code[br].Descriptor == Instruction::Type::JMP);
+		m_Code[br].Values.Address[0] = addr;
+	}
+	m_ContinueScopeStack.pop();
+};
+
 size_t ByteCodeGenerator::PushInstruction(Instruction::Type opcode, const IPLString& arg0, const IPLString& arg1, const IPLString& arg2)
 {
 	assert(CheckOpCode(opcode));
@@ -337,15 +388,60 @@ void ByteCodeGenerator::Visit(IfStatement* e)
 
 void ByteCodeGenerator::Visit(ForStatement* e)
 {
+	OpenBreakScope();
+	OpenContinueScope();
+
 	e->GetInitialization()->Accept(*this);
 	auto compareAddress = m_Code.size();
 	e->GetCondition()->Accept(*this);
 	auto endAddress = PushInstruction(Instruction::Type::JMPF, m_RegisterStack.top(), (size_t)0);
 	m_RegisterStack.pop();
 	e->GetBody()->Accept(*this);
+
+	auto iterationAddress = m_Code.size();
 	e->GetIteration()->Accept(*this);
+	
 	PushInstruction(Instruction::Type::JMP, compareAddress);
 	m_Code[endAddress].Values.Address[0] = m_Code.size();
+
+	CloseBreakScope(m_Code.size());
+	CloseContinueScope(iterationAddress);
+}
+
+void ByteCodeGenerator::Visit(WhileStatement* e)
+{
+	auto startAddress = m_Code.size();
+
+	OpenBreakScope();
+	OpenContinueScope();
+
+	if (e->GetDoWhile())
+	{
+		e->GetBody()->Accept(*this);
+		e->GetCondition()->Accept(*this);
+		PushInstruction(Instruction::Type::JMPT, m_RegisterStack.top(), startAddress);
+	}
+	else {
+		e->GetCondition()->Accept(*this);
+		auto endAddress = PushInstruction(Instruction::Type::JMPF, m_RegisterStack.top(), (size_t)0);
+		m_RegisterStack.pop();
+		e->GetBody()->Accept(*this);
+		PushInstruction(Instruction::Type::JMP, startAddress);
+		m_Code[endAddress].Values.Address[0] = m_Code.size();
+	}
+
+	CloseBreakScope(m_Code.size());
+	CloseContinueScope(startAddress);
+}
+
+void ByteCodeGenerator::Visit(Break*)
+{
+	PushBreak();
+}
+
+void ByteCodeGenerator::Visit(Continue*)
+{
+	PushContinue();
 }
 
 void ByteCodeGenerator::Visit(IdentifierExpression* e)
@@ -485,6 +581,29 @@ void ByteCodeGenerator::Visit(LiteralString* e)
 	m_RegisterStack.push(stringReg);
 }
 
+void ByteCodeGenerator::Visit(Call* e)
+{
+	e->GetObjectOrCall()->Accept(*this);
+	if (e->GetMember())
+	{
+		e->GetMember()->Accept(*this);
+	}
+}
+
+void ByteCodeGenerator::Visit(MemberAccess* e)
+{
+	auto objectReg = m_RegisterStack.top();
+	m_RegisterStack.pop();
+
+	auto identifierNameReg = CreateRegister();
+	PushInstruction(Instruction::Type::STRING, identifierNameReg, e->GetName());
+
+	auto resultReg = CreateRegister();
+	PushInstruction(Instruction::Type::GET, objectReg,  identifierNameReg, resultReg);
+
+	m_RegisterStack.push(resultReg);
+}
+
 unsigned ByteCodeGenerator::ResolveRegisterName(IPLString& name)
 {
 	auto it = std::find_if(m_RegisterTable.begin(), m_RegisterTable.end(), [&](IPLString& current) {
-- 
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