From 9e7773a0f9ca7af2d1a2281c4cd510c46ea71966 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Thu, 14 Oct 2021 18:15:04 +0200
Subject: [PATCH] Add warning for constant out of bound array access

---
 oscar64/Errors.h               |  1 +
 oscar64/InterCodeGenerator.cpp | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/oscar64/Errors.h b/oscar64/Errors.h
index a2f9fe1..73b80d0 100644
--- a/oscar64/Errors.h
+++ b/oscar64/Errors.h
@@ -16,6 +16,7 @@ enum ErrorID
 	EWARN_GENERIC = 2000,
 	EWARN_CONSTANT_TRUNCATED,
 	EWARN_UNKNOWN_PRAGMA,
+	EWARN_INDEX_OUT_OF_BOUNDS,
 	EWARN_SYNTAX,
 
 	EERR_GENERIC = 3000,
diff --git a/oscar64/InterCodeGenerator.cpp b/oscar64/InterCodeGenerator.cpp
index 2004926..477722e 100644
--- a/oscar64/InterCodeGenerator.cpp
+++ b/oscar64/InterCodeGenerator.cpp
@@ -1119,6 +1119,16 @@ InterCodeGenerator::ExValue InterCodeGenerator::TranslateExpression(Declaration*
 			vl = TranslateExpression(procType, proc, block, exp->mLeft, breakBlock, continueBlock, inlineMapper);
 			vr = TranslateExpression(procType, proc, block, exp->mRight, breakBlock, continueBlock, inlineMapper);
 
+			if (vl.mType->mType == DT_TYPE_ARRAY && exp->mRight->mType == EX_CONSTANT && exp->mRight->mDecValue->mType == DT_CONST_INTEGER)
+			{
+				if (vl.mType->mFlags & DTF_DEFINED)
+				{
+					int64	index = exp->mRight->mDecValue->mInteger;
+					if (index < 0 || index * vl.mType->mBase->mSize >= vl.mType->mSize)
+						mErrors->Error(exp->mLocation, EWARN_INDEX_OUT_OF_BOUNDS, "Constant array index out of bounds");
+				}
+			}
+
 			vl = Dereference(proc, block, vl, vl.mType->mType == DT_TYPE_POINTER ? 0 : 1);
 			vr = Dereference(proc, block, vr);