From 8ab8b3c2a1e892824e1721aad77da64969ec99ac Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Tue, 26 Oct 2021 14:44:25 +0200
Subject: [PATCH] Fix negative array indices

---
 oscar64/ByteCodeGenerator.cpp   | 18 +++++++++---------
 oscar64/NativeCodeGenerator.cpp |  2 +-
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/oscar64/ByteCodeGenerator.cpp b/oscar64/ByteCodeGenerator.cpp
index e0fb162..e5bb949 100644
--- a/oscar64/ByteCodeGenerator.cpp
+++ b/oscar64/ByteCodeGenerator.cpp
@@ -916,7 +916,7 @@ void ByteCodeBasicBlock::StoreDirectValue(InterCodeProcedure* proc, const InterI
 				if (ins->mSrc[1].mMemory == IM_INDIRECT)
 				{
 					int	index = ins->mSrc[1].mIntConst;
-					if (index + 4 <= 256)
+					if (index >= 0 && index + 4 <= 256)
 					{
 						ByteCodeInstruction	lins(BC_ADDR_REG);
 						lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[1].mTemp];
@@ -944,7 +944,7 @@ void ByteCodeBasicBlock::StoreDirectValue(InterCodeProcedure* proc, const InterI
 				if (ins->mSrc[1].mMemory == IM_INDIRECT)
 				{
 					int	index = ins->mSrc[1].mIntConst;
-					if (index + 4 <= 256)
+					if (index >= 0 && index + 4 <= 256)
 					{
 						ByteCodeInstruction	lins(BC_ADDR_REG);
 						lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[1].mTemp];
@@ -1113,7 +1113,7 @@ void ByteCodeBasicBlock::StoreDirectValue(InterCodeProcedure* proc, const InterI
 				if (ins->mSrc[1].mMemory == IM_INDIRECT)
 				{
 					int	index = ins->mSrc[1].mIntConst;
-					if (index + 2 <= 256)
+					if (index >= 0 && index + 2 <= 256)
 					{
 						ByteCodeInstruction	lins(BC_ADDR_REG);
 						lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[1].mTemp];
@@ -1141,7 +1141,7 @@ void ByteCodeBasicBlock::StoreDirectValue(InterCodeProcedure* proc, const InterI
 				if (ins->mSrc[1].mMemory == IM_INDIRECT)
 				{
 					int	index = ins->mSrc[1].mIntConst;
-					if (index + 2 <= 256)
+					if (index >= 0 && index + 2 <= 256)
 					{
 						ByteCodeInstruction	lins(BC_ADDR_REG);
 						lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[1].mTemp];
@@ -1579,7 +1579,7 @@ void ByteCodeBasicBlock::StoreDirectValue(InterCodeProcedure* proc, const InterI
 				if (ins->mSrc[1].mMemory == IM_INDIRECT)
 				{
 					int	index = ins->mSrc[1].mIntConst;
-					if (index + InterTypeSize[ins->mSrc[0].mType] <= 256)
+					if (index >= 0 && index + InterTypeSize[ins->mSrc[0].mType] <= 256)
 					{
 						ByteCodeInstruction	lins(BC_ADDR_REG);
 						lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[1].mTemp];
@@ -1624,7 +1624,7 @@ void ByteCodeBasicBlock::StoreDirectValue(InterCodeProcedure* proc, const InterI
 				if (ins->mSrc[1].mMemory == IM_INDIRECT)
 				{
 					int	index = ins->mSrc[1].mIntConst;
-					if (index + InterTypeSize[ins->mSrc[0].mType] <= 256)
+					if (index >= 0 && index + InterTypeSize[ins->mSrc[0].mType] <= 256)
 					{
 						ByteCodeInstruction	lins(BC_ADDR_REG);
 						lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[1].mTemp];
@@ -1736,7 +1736,7 @@ void ByteCodeBasicBlock::LoadDirectValue(InterCodeProcedure* proc, const InterIn
 			if (ins->mSrc[0].mMemory == IM_INDIRECT)
 			{
 				int	index = ins->mSrc[0].mIntConst;
-				if (index + 4 <= 256)
+				if (index >= 0 && index + 4 <= 256)
 				{
 					ByteCodeInstruction	lins(BC_ADDR_REG);
 					lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[0].mTemp];
@@ -1823,7 +1823,7 @@ void ByteCodeBasicBlock::LoadDirectValue(InterCodeProcedure* proc, const InterIn
 			if (ins->mSrc[0].mMemory == IM_INDIRECT)
 			{
 				int	index = ins->mSrc[0].mIntConst;
-				if (index + 2 <= 256)
+				if (index >= 0 && index + 2 <= 256)
 				{
 					ByteCodeInstruction	lins(BC_ADDR_REG);
 					lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[0].mTemp];
@@ -2025,7 +2025,7 @@ void ByteCodeBasicBlock::LoadDirectValue(InterCodeProcedure* proc, const InterIn
 			if (ins->mSrc[0].mMemory == IM_INDIRECT)
 			{
 				int	index = ins->mSrc[0].mIntConst;
-				if (index + InterTypeSize[ins->mDst.mType] <= 256)
+				if (index >= 0 && index + InterTypeSize[ins->mDst.mType] <= 256)
 				{
 					ByteCodeInstruction	lins(BC_ADDR_REG);
 					lins.mRegister = BC_REG_TMP + proc->mTempOffset[ins->mSrc[0].mTemp];
diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index f92d516..886e7ab 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -2513,7 +2513,7 @@ void NativeCodeBasicBlock::LoadConstant(InterCodeProcedure* proc, const InterIns
 
 void NativeCodeBasicBlock::CheckFrameIndex(int& reg, int& index, int size)
 {
-	if (index + size > 256)
+	if (index < 0 || index + size > 256)
 	{
 		mIns.Push(NativeCodeInstruction(ASMIT_CLC, ASMIM_IMPLIED));
 		mIns.Push(NativeCodeInstruction(ASMIT_LDA, ASMIM_ZERO_PAGE, reg));