From c2886e2532745e4a5a74f335738c75d6d629d779 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Sat, 16 Oct 2021 10:49:11 +0200
Subject: [PATCH] Fix infinite for(;;) loop

---
 oscar64/InterCode.cpp | 14 +++++++++++++-
 oscar64/Parser.cpp    | 12 ++++++++++--
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/oscar64/InterCode.cpp b/oscar64/InterCode.cpp
index 218d266..ac2a3ce 100644
--- a/oscar64/InterCode.cpp
+++ b/oscar64/InterCode.cpp
@@ -1856,6 +1856,18 @@ void InterCodeBasicBlock::CollectEntries(void)
 	}
 }
 
+static bool IsInfiniteLoop(const InterCodeBasicBlock* block)
+{
+	const InterCodeBasicBlock* nblock = block;
+	while (nblock->mTrueJump && !nblock->mFalseJump)
+	{
+		nblock = nblock->mTrueJump;
+		if (nblock == block)
+			return true;
+	}
+	return false;
+}
+
 void InterCodeBasicBlock::GenerateTraces(void)
 {
 	int i;
@@ -1884,7 +1896,7 @@ void InterCodeBasicBlock::GenerateTraces(void)
 				if (mFalseJump)
 					mFalseJump->mNumEntries++;
 			}
-			else if (mTrueJump && !mFalseJump && ((mTrueJump->mInstructions.Size() < 10 && mTrueJump->mInstructions.Size() > 1) || mTrueJump->mNumEntries == 1) && !mTrueJump->mLoopHead)
+			else if (mTrueJump && !mFalseJump && ((mTrueJump->mInstructions.Size() < 10 && mTrueJump->mInstructions.Size() > 1) || mTrueJump->mNumEntries == 1) && !mTrueJump->mLoopHead && !IsInfiniteLoop(mTrueJump))
 			{
 				mTrueJump->mNumEntries--;
 
diff --git a/oscar64/Parser.cpp b/oscar64/Parser.cpp
index 5c0a632..bad405c 100644
--- a/oscar64/Parser.cpp
+++ b/oscar64/Parser.cpp
@@ -1721,16 +1721,24 @@ Expression* Parser::ParseStatement(void)
 				exp = new Expression(mScanner->mLocation, EX_FOR);
 				exp->mLeft = new Expression(mScanner->mLocation, EX_SEQUENCE);
 				exp->mLeft->mLeft = new Expression(mScanner->mLocation, EX_SEQUENCE);
-				exp->mLeft->mRight = ParseExpression();
+
+				// Assignment
+				if (mScanner->mToken != TK_SEMICOLON)
+					exp->mLeft->mRight = ParseExpression();
 				if (mScanner->mToken == TK_SEMICOLON)
 					mScanner->NextToken();
 				else
 					mErrors->Error(mScanner->mLocation, EERR_SYNTAX, "';' expected");
-				exp->mLeft->mLeft->mLeft = ParseExpression();
+
+				// Condition
+				if (mScanner->mToken != TK_SEMICOLON)
+					exp->mLeft->mLeft->mLeft = ParseExpression();
 				if (mScanner->mToken == TK_SEMICOLON)
 					mScanner->NextToken();
 				else
 					mErrors->Error(mScanner->mLocation, EERR_SYNTAX, "';' expected");
+
+				// Iteration
 				if (mScanner->mToken != TK_CLOSE_PARENTHESIS)
 					exp->mLeft->mLeft->mRight = ParseExpression();
 				if (mScanner->mToken == TK_CLOSE_PARENTHESIS)