From f8eaabfc556b76bfc44b4785d4fbac2df66bb34f Mon Sep 17 00:00:00 2001
From: Tijmen van Nesselrooij <tijmen_222@hotmail.com>
Date: Sat, 16 May 2020 12:17:10 +0200
Subject: [PATCH] Add exit operand

---
 bin/test.wasm                        | 6 ++----
 include/execute/state.hpp            | 1 +
 include/interpret/statement.hpp      | 5 +++++
 include/token/operandtype.hpp        | 1 +
 src/execute/state.cpp                | 3 ++-
 src/execute/virtualmachine.cpp       | 2 +-
 src/interpret/operanddefinitions.cpp | 6 ++++++
 src/interpret/statement.cpp          | 5 +++++
 src/token/operandtype.cpp            | 1 +
 9 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/bin/test.wasm b/bin/test.wasm
index 515e672..5deeb94 100644
--- a/bin/test.wasm
+++ b/bin/test.wasm
@@ -91,9 +91,7 @@ int $3;
 # Jump over the interrupt
 call noop_function;
 int $3;
-jmp the_real_exit;
+exit;
 
 noop_function:
-ret;
-
-the_real_exit:
\ No newline at end of file
+ret;
\ No newline at end of file
diff --git a/include/execute/state.hpp b/include/execute/state.hpp
index 955bc0d..2a973b3 100644
--- a/include/execute/state.hpp
+++ b/include/execute/state.hpp
@@ -13,6 +13,7 @@ namespace Execute
 		std::vector<InterruptFn> const interrupts;
 		std::vector<std::uint8_t> memory;
 		unsigned stackPointer;
+		bool terminated;
 
 		State(std::unordered_map<std::string, unsigned> const & labelStatementIndice, unsigned const memorySize);
 	};
diff --git a/include/interpret/statement.hpp b/include/interpret/statement.hpp
index 7e900c1..2760f83 100644
--- a/include/interpret/statement.hpp
+++ b/include/interpret/statement.hpp
@@ -71,6 +71,11 @@ namespace Interpret
 		void Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers) override;
 	};
 
+	struct ExitProgramStatement : Statement
+	{
+		void Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers) override;
+	};
+
 	struct SetStatement : Statement
 	{
 		Value firstArgument;
diff --git a/include/token/operandtype.hpp b/include/token/operandtype.hpp
index 56bc07b..e3a9f49 100644
--- a/include/token/operandtype.hpp
+++ b/include/token/operandtype.hpp
@@ -15,6 +15,7 @@ namespace Token
 		Jump,
 		CallFunction,
 		ReturnFromFunction,
+		ExitProgram,
 		LessThanInteger,
 		GreaterThanInteger,
 		EqualInteger,
diff --git a/src/execute/state.cpp b/src/execute/state.cpp
index 164a621..7d81d26 100644
--- a/src/execute/state.cpp
+++ b/src/execute/state.cpp
@@ -8,7 +8,8 @@ namespace Execute
 		labelStatementIndice(_labelStatementIndice),
 		interrupts(GetInterrupts()),
 		memory(memorySize),
-		stackPointer(0u)
+		stackPointer(0u),
+		terminated(false)
 	{
 	}
 }
\ No newline at end of file
diff --git a/src/execute/virtualmachine.cpp b/src/execute/virtualmachine.cpp
index b0a999d..f31d260 100644
--- a/src/execute/virtualmachine.cpp
+++ b/src/execute/virtualmachine.cpp
@@ -21,7 +21,7 @@ namespace Execute
 		}
 
 		state.currentStatement = state.nextStatement;
-		if (state.currentStatement >= code.statements.size())
+		if (state.currentStatement >= code.statements.size() || state.terminated)
 		{
 			terminated = true;
 		}
diff --git a/src/interpret/operanddefinitions.cpp b/src/interpret/operanddefinitions.cpp
index 4bbb64f..6bd1e22 100644
--- a/src/interpret/operanddefinitions.cpp
+++ b/src/interpret/operanddefinitions.cpp
@@ -170,6 +170,11 @@ namespace Interpret
 				return std::make_unique<ReturnFromFunctionStatement>();
 			}
 
+			case Token::OperandType::ExitProgram:
+			{
+				return std::make_unique<ExitProgramStatement>();
+			}
+
 			case Token::OperandType::LessThanInteger:
 			{
 				auto statement = std::make_unique<ControlFlowStatement>();
@@ -316,6 +321,7 @@ namespace Interpret
 			default:
 			std::printf("WARNING: returning default argument length of 0 for operand type %i\n", static_cast<int>(type));
 			case Token::OperandType::ReturnFromFunction:
+			case Token::OperandType::ExitProgram:
 			return 0;
 		}
 	}
diff --git a/src/interpret/statement.cpp b/src/interpret/statement.cpp
index 82569d4..bd9b789 100644
--- a/src/interpret/statement.cpp
+++ b/src/interpret/statement.cpp
@@ -77,6 +77,11 @@ namespace Interpret
 		state.stackPointer -= sizeof(unsigned);
 	}
 
+	void ExitProgramStatement::Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers)
+	{
+		state.terminated = true;
+	}
+
 	void SetStatement::Execute(Execute::Flags & flags, Execute::State & state, Execute::Registers & registers)
 	{
 		firstArgument.GetValue(state, registers) = secondArgument.GetValue(state, registers);
diff --git a/src/token/operandtype.cpp b/src/token/operandtype.cpp
index c8b4789..9341bbb 100644
--- a/src/token/operandtype.cpp
+++ b/src/token/operandtype.cpp
@@ -16,6 +16,7 @@ namespace Token
 			{ "jmp", OperandType::Jump },
 			{ "call", OperandType::CallFunction },
 			{ "ret", OperandType::ReturnFromFunction },
+			{ "exit", OperandType::ExitProgram },
 			{ "lti", OperandType::LessThanInteger },
 			{ "gti", OperandType::GreaterThanInteger },
 			{ "eqi", OperandType::EqualInteger },