Add call operand

bin/example.wasm

@@ -39,7 +39,7 @@ int $0;
 pushi $68; # D
 pushi $76; # L
 pushi $82; # R
-pushi $79; # O 
+pushi $79; # O
 pushi $87; # W
 
 seti %B $5;
@@ -72,17 +72,23 @@ seti %A [$1024];
 int $2;
 
 # Push the string "hell" into register A
-seti %A $108;
+seti %A $108;    # l
 shli %A $8 %A;
-addi %A $108 %A;
+addi %A $108 %A; # l
 shli %A $8 %A;
-addi %A $101 %A;
+addi %A $101 %A; # e
 shli %A $8 %A;
-addi %A $104 %A;
+addi %A $104 %A; # h
 
-# Store A at 900
+# Store A at memory location 900
 seti [$900] %A;
+
 # Setup to print a string from position 900
 seti %A $900;
 seti %B $4;
-int $3;
+int $3;
+
+# Jump over the interrupt
+call program_exit;
+int $3;
+program_exit:

include/execute/virtualmachine.hpp

@@ -27,7 +27,7 @@ namespace Execute
 		Registers const & GetRegisters() const;
 		State const & GetState() const;
 		Interpret::Statement const * const GetCurrentStatement() const;
-		
+
 		bool IsTerminated() const;
 
 		static VirtualMachine CreateFromCode(Interpret::Code const & code);

include/interpret/statement.hpp

@@ -30,7 +30,7 @@ namespace Interpret
 		void (* function)(Execute::State & state, int argument1, int argument2);
 		Value firstArgument;
 		Value secondArgument;
-		
+
 		void Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers) override;
 	};
 
@@ -40,7 +40,7 @@ namespace Interpret
 		Value firstArgument;
 		Value secondArgument;
 		Value thirdArgument;
-		
+
 		void Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers) override;
 	};
 
@@ -55,6 +55,17 @@ namespace Interpret
 		JumpStatement(std::string const & label);
 	};
 
+	struct FunctionCallStatement : Statement
+	{
+	private:
+		std::string const label;
+
+	public:
+		void Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers) override;
+
+		FunctionCallStatement(std::string const & label);
+	};
+
 	struct SetStatement : Statement
 	{
 		Value firstArgument;

include/token/operandtype.hpp

@@ -13,6 +13,7 @@ namespace Token
 		ShiftIntegerLeft,
 		ShiftIntegerRight,
 		Jump,
+		CallFunction,
 		LessThanInteger,
 		GreaterThanInteger,
 		EqualInteger,

src/execute/virtualmachine.cpp

@@ -5,9 +5,9 @@ namespace Execute
 	void VirtualMachine::Step()
 	{
 		state.nextStatement = state.currentStatement + 1u;
-		
+
 		code.statements[state.currentStatement]->Execute(flags, state, registers);
-		
+
 		state.currentStatement = state.nextStatement;
 		if (state.currentStatement >= code.statements.size())
 		{
@@ -48,7 +48,7 @@ namespace Execute
 		return code.statements[state.currentStatement].get();
 	}
 
-	bool VirtualMachine::IsTerminated() const { return terminated; } 
+	bool VirtualMachine::IsTerminated() const { return terminated; }
 
 	VirtualMachine VirtualMachine::CreateFromCode(Interpret::Code const & code)
 	{

src/interpret/operanddefinitions.cpp

@@ -150,9 +150,21 @@ namespace Interpret
 				{
 					throw ExpectedLabel(labelToken);
 				}
+
 				return std::make_unique<JumpStatement>(std::get<std::string>(labelToken.data));
 			}
 
+			case Token::OperandType::CallFunction:
+			{
+				auto labelToken = tokens[operandIndex + 1u];
+				if (labelToken.type != Token::TokenType::Label)
+				{
+					throw ExpectedLabel(labelToken);
+				}
+
+				return std::make_unique<FunctionCallStatement>(std::get<std::string>(labelToken.data));
+			}
+
 			case Token::OperandType::LessThanInteger:
 			{
 				auto statement = std::make_unique<ControlFlowStatement>();
@@ -243,9 +255,12 @@ namespace Interpret
 			default:
 			{
 				auto statement = std::make_unique<NoArgumentStatement>();
-				
+
 				// TODO throw error?
-				statement->function = [](Execute::Flags & flags, Execute::Registers & registers) { std::puts("ExtractStatement: Extracted unhandled operator type"); };
+				statement->function = [](Execute::Flags & flags, Execute::Registers & registers)
+				{
+					std::puts("ExtractStatement: Extracted unhandled operator type");
+				};
 				return statement;
 			}
 		}
@@ -287,6 +302,7 @@ namespace Interpret
 			return 2;
 
 			case Token::OperandType::Jump:
+			case Token::OperandType::CallFunction:
 			case Token::OperandType::Interrupt:
 			case Token::OperandType::PushInteger:
 			case Token::OperandType::PopInteger:

src/interpret/statement.cpp

@@ -1,5 +1,6 @@
 #include <execute/error.hpp>
 #include <interpret/statement.hpp>
+#include <stdexcept>
 
 namespace Interpret
 {
@@ -41,6 +42,30 @@ namespace Interpret
 	{
 	}
 
+	void FunctionCallStatement::Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers)
+	{
+		auto const & elem = state.labelStatementIndice.find(label);
+		if (elem == state.labelStatementIndice.end())
+		{
+			throw std::runtime_error("Attempted call nonexisting function (missing label)");
+		}
+
+		if ((state.memory.size() - state.stackPointer) < sizeof(unsigned))
+		{
+			throw Execute::StackOverflow();
+		}
+
+		*(reinterpret_cast<unsigned *>(state.memory.data() + state.stackPointer + (sizeof(unsigned) - 1))) = state.nextStatement;
+
+		state.stackPointer += sizeof(int);
+		state.nextStatement = elem->second;
+	}
+
+	FunctionCallStatement::FunctionCallStatement(std::string const & _label)
+		: label(_label)
+	{
+	}
+
 	void SetStatement::Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers)
 	{
 		firstArgument.GetValue(state, registers) = secondArgument.GetValue(state, registers);

src/token/operandtype.cpp

@@ -14,6 +14,7 @@ namespace Token
 			{ "shri", OperandType::ShiftIntegerRight },
 			{ "shli", OperandType::ShiftIntegerLeft },
 			{ "jmp", OperandType::Jump },
+			{ "call", OperandType::CallFunction },
 			{ "lti", OperandType::LessThanInteger },
 			{ "gti", OperandType::GreaterThanInteger },
 			{ "eqi", OperandType::EqualInteger },

src/token/token.cpp

@@ -57,8 +57,8 @@ namespace Token
 		: lineNumber(other.lineNumber),
 		lineColumn(other.lineColumn),
 		type(other.type),
-		isValid(other.isValid),
 		valueType(other.valueType),
+		isValid(other.isValid),
 		data(other.data)
 	{
 	}

src/token/tokenizer.cpp

@@ -1,4 +1,5 @@
 #include <map>
+#include <stdexcept>
 #include <token/tokenizer.hpp>
 
 namespace Token