From feade14fd62a566ee9c9c2da525b3b0ee346beeb Mon Sep 17 00:00:00 2001
From: ChrisXXXXXXX <95465284+ChrisXXXXXXX@users.noreply.github.com>
Date: Tue, 15 Nov 2022 12:29:55 +0300
Subject: [PATCH] Update ControlFlowSideEffectsCollector.cpp

There are errors in the function void ControlFlowBuilder::operator()(If const& _if) and function void ControlFlowBuilder::operator()(Switch const& _switch) when calculating CFG.
1. In the function void ControlFlowBuilder::operator()(If const& _if), the if.condion block is not the same block as the if.then block. The original code is calculated as one same block.
2. The switch.expression block are not the same block as all the cases block in cases, the original code is calculated as one same block.
This can cause some potential problems during the optimization phase.
---
 libyul/ControlFlowSideEffectsCollector.cpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/libyul/ControlFlowSideEffectsCollector.cpp b/libyul/ControlFlowSideEffectsCollector.cpp
index 19eb8275d..ddf53743a 100644
--- a/libyul/ControlFlowSideEffectsCollector.cpp
+++ b/libyul/ControlFlowSideEffectsCollector.cpp
@@ -51,9 +51,15 @@ void ControlFlowBuilder::operator()(If const& _if)
 {
 	visit(*_if.condition);
 	ControlFlowNode* node = m_currentNode;
-	(*this)(_if.body);
+
+	ControlFlowNode* ifEnd = newNode();
+	node->successors.emplace_back(ifEnd);
+
 	newConnectedNode();
-	node->successors.emplace_back(m_currentNode);
+	(*this)(_if.body);
+
+	m_currentNode->successors.emplace_back(ifEnd);
+	m_currentNode = ifEnd;
 }
 
 void ControlFlowBuilder::operator()(Switch const& _switch)
@@ -68,8 +74,8 @@ void ControlFlowBuilder::operator()(Switch const& _switch)
 	for (Case const& case_: _switch.cases)
 	{
 		m_currentNode = initialNode;
-		(*this)(case_.body);
 		newConnectedNode();
+		(*this)(case_.body);
 		m_currentNode->successors.emplace_back(finalNode);
 	}
 	m_currentNode = finalNode;
@@ -282,4 +288,3 @@ void ControlFlowSideEffectsCollector::recordReachabilityAndQueue(
 	if (m_processedNodes[&_function].insert(_node).second)
 		m_pendingNodes.at(&_function).push_front(_node);
 }
-