From fb06451f45c6e1dc0ffe304c2074ead6ba03f1ec Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Mon, 15 Apr 2019 15:15:48 +0200
Subject: [PATCH] Add assertion that DeadCodeEliminator needs
 ForLoopInitRewriter.

---
 libyul/optimiser/DeadCodeEliminator.cpp                   | 6 ++++++
 libyul/optimiser/DeadCodeEliminator.h                     | 1 +
 test/libyul/YulOptimizerTest.cpp                          | 1 +
 test/libyul/yulOptimizerTests/fullSimplify/inside_for.yul | 2 +-
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/libyul/optimiser/DeadCodeEliminator.cpp b/libyul/optimiser/DeadCodeEliminator.cpp
index 47f302d4f..c405f2d76 100644
--- a/libyul/optimiser/DeadCodeEliminator.cpp
+++ b/libyul/optimiser/DeadCodeEliminator.cpp
@@ -67,6 +67,12 @@ auto findFirstTerminatingStatement(Block& _block)
 }
 }
 
+void DeadCodeEliminator::operator()(ForLoop& _for)
+{
+	yulAssert(_for.pre.statements.empty(), "DeadCodeEliminator needs ForLoopInitRewriter as a prerequisite.");
+	ASTModifier::operator()(_for);
+}
+
 void DeadCodeEliminator::operator()(Block& _block)
 {
 	auto& statements = _block.statements;
diff --git a/libyul/optimiser/DeadCodeEliminator.h b/libyul/optimiser/DeadCodeEliminator.h
index 1d464badd..c4d60cf4c 100644
--- a/libyul/optimiser/DeadCodeEliminator.h
+++ b/libyul/optimiser/DeadCodeEliminator.h
@@ -47,6 +47,7 @@ class DeadCodeEliminator: public ASTModifier
 {
 public:
 	using ASTModifier::operator();
+	void operator()(ForLoop& _for) override;
 	void operator()(Block& _block) override;
 };
 
diff --git a/test/libyul/YulOptimizerTest.cpp b/test/libyul/YulOptimizerTest.cpp
index e5fe097f7..3eec1233f 100644
--- a/test/libyul/YulOptimizerTest.cpp
+++ b/test/libyul/YulOptimizerTest.cpp
@@ -192,6 +192,7 @@ bool YulOptimizerTest::run(ostream& _stream, string const& _linePrefix, bool con
 		disambiguate();
 		NameDispenser nameDispenser{*m_dialect, *m_ast};
 		ExpressionSplitter{*m_dialect, nameDispenser}(*m_ast);
+		ForLoopInitRewriter{}(*m_ast);
 		CommonSubexpressionEliminator{*m_dialect}(*m_ast);
 		ExpressionSimplifier::run(*m_dialect, *m_ast);
 		UnusedPruner::runUntilStabilised(*m_dialect, *m_ast);
diff --git a/test/libyul/yulOptimizerTests/fullSimplify/inside_for.yul b/test/libyul/yulOptimizerTests/fullSimplify/inside_for.yul
index f18d73f26..a2365cf0d 100644
--- a/test/libyul/yulOptimizerTests/fullSimplify/inside_for.yul
+++ b/test/libyul/yulOptimizerTests/fullSimplify/inside_for.yul
@@ -6,8 +6,8 @@
 // step: fullSimplify
 // ----
 // {
+//     let a := 10
 //     for {
-//         let a := 10
 //     }
 //     iszero(iszero(a))
 //     {