[Sol -> Yul] Fix ForLoops and implement WhileLoops

libsolidity/codegen/ir/IRGeneratorForStatements.cpp

@@ -152,27 +152,28 @@ bool IRGeneratorForStatements::visit(TupleExpression const& _tuple)
 	return false;
 }
 
-bool IRGeneratorForStatements::visit(ForStatement const& _for)
+bool IRGeneratorForStatements::visit(ForStatement const& _forStatement)
 {
-	m_code << "for {\n";
-	if (_for.initializationExpression())
-		_for.initializationExpression()->accept(*this);
-	m_code << "} return_flag {\n";
-	if (_for.loopExpression())
-		_for.loopExpression()->accept(*this);
-	m_code << "}\n";
-	if (_for.condition())
-	{
-		_for.condition()->accept(*this);
-		m_code <<
-			"if iszero(" <<
-			expressionAsType(*_for.condition(), *TypeProvider::boolean()) <<
-			") { break }\n";
-	}
-	_for.body().accept(*this);
-	m_code << "}\n";
-	// Bubble up the return condition.
-	m_code << "if iszero(return_flag) { break }\n";
+	generateLoop(
+		_forStatement.body(),
+		_forStatement.condition(),
+		_forStatement.initializationExpression(),
+		_forStatement.loopExpression()
+	);
+
+	return false;
+}
+
+bool IRGeneratorForStatements::visit(WhileStatement const& _whileStatement)
+{
+	generateLoop(
+		_whileStatement.body(),
+		&_whileStatement.condition(),
+		nullptr,
+		nullptr,
+		_whileStatement.isDoWhile()
+	);
+
 	return false;
 }
 
@@ -796,6 +797,54 @@ void IRGeneratorForStatements::setLValue(Expression const& _expression, unique_p
 		defineExpression(_expression) << _lvalue->retrieveValue() << "\n";
 }
 
+void IRGeneratorForStatements::generateLoop(
+	Statement const& _body,
+	Expression const* _conditionExpression,
+	Statement const*  _initExpression,
+	ExpressionStatement const* _loopExpression,
+	bool _isDoWhile
+)
+{
+	string firstRun;
+
+	if (_isDoWhile)
+	{
+		solAssert(_conditionExpression, "Expected condition for doWhile");
+		firstRun = m_context.newYulVariable();
+		m_code << "let " << firstRun << " := 1\n";
+	}
+
+	m_code << "for {\n";
+	if (_initExpression)
+		_initExpression->accept(*this);
+	m_code << "} return_flag {\n";
+	if (_loopExpression)
+		_loopExpression->accept(*this);
+	m_code << "}\n";
+	m_code << "{\n";
+
+	if (_conditionExpression)
+	{
+		if (_isDoWhile)
+			m_code << "if iszero(" << firstRun << ") {\n";
+
+		_conditionExpression->accept(*this);
+		m_code <<
+			"if iszero(" <<
+			expressionAsType(*_conditionExpression, *TypeProvider::boolean()) <<
+			") { break }\n";
+
+		if (_isDoWhile)
+			m_code << "}\n" << firstRun << " := 0\n";
+	}
+
+	_body.accept(*this);
+
+	m_code << "}\n";
+	// Bubble up the return condition.
+	m_code << "if iszero(return_flag) { break }\n";
+}
+
 Type const& IRGeneratorForStatements::type(Expression const& _expression)
 {
 	solAssert(_expression.annotation().type, "Type of expression not set.");

libsolidity/codegen/ir/IRGeneratorForStatements.h

@@ -49,6 +49,7 @@ public:
 	bool visit(Assignment const& _assignment) override;
 	bool visit(TupleExpression const& _tuple) override;
 	bool visit(ForStatement const& _forStatement) override;
+	bool visit(WhileStatement const& _whileStatement) override;
 	bool visit(Continue const& _continueStatement) override;
 	bool visit(Break const& _breakStatement) override;
 	void endVisit(Return const& _return) override;
@@ -70,6 +71,13 @@ private:
 	void appendAndOrOperatorCode(BinaryOperation const& _binOp);
 
 	void setLValue(Expression const& _expression, std::unique_ptr<IRLValue> _lvalue);
+	void generateLoop(
+		Statement const& _body,
+		Expression const* _conditionExpression,
+		Statement const*  _initExpression = nullptr,
+		ExpressionStatement const* _loopExpression = nullptr,
+		bool _isDoWhile = false
+	);
 
 	static Type const& type(Expression const& _expression);
 

test/libsolidity/semanticTests/viaYul/loops/break.sol

@@ -0,0 +1,31 @@
+contract C {
+    function f() public returns (uint x) {
+        x = 1;
+        for (uint a = 0; a < 10; a = a + 1) {
+            x = x + x;
+            break;
+        }
+    }
+    function g() public returns (uint x) {
+        x = 1;
+        uint a = 0;
+        while (a < 10) {
+            x = x + x;
+            break;
+            a = a + 1;
+        }
+    }
+    function h() public returns (uint x) {
+        x = 1;
+        do {
+            x = x + 1;
+            break;
+        } while (x < 3);
+    }
+}
+// ====
+// compileViaYul: true
+// ----
+// f() -> 2
+// g() -> 2
+// h() -> 2

test/libsolidity/semanticTests/viaYul/loops/continue.sol

@@ -0,0 +1,37 @@
+contract C {
+    function f() public returns (uint x) {
+        x = 1;
+        uint a = 0;
+        for (; a < 10; a = a + 1) {
+            continue;
+            x = x + x;
+        }
+        x = x + a;
+    }
+    function g() public returns (uint x) {
+        x = 1;
+        uint a = 0;
+        while (a < 10) {
+            a = a + 1;
+            continue;
+            x = x + x;
+        }
+        x = x + a;
+    }
+    function h() public returns (uint x) {
+        x = 1;
+        uint a = 0;
+        do {
+            a = a + 1;
+            continue;
+            x = x + x;
+        } while (a < 4);
+        x = x + a;
+    }
+}
+// ====
+// compileViaYul: true
+// ----
+// f() -> 11
+// g() -> 11
+// h() -> 5

test/libsolidity/semanticTests/viaYul/loops/return.sol

@@ -0,0 +1,34 @@
+contract C {
+    function f() public returns (uint x) {
+        x = 1;
+        uint a;
+        for (; a < 10; a = a + 1) {
+            return x;
+            x = x + x;
+        }
+        x = x + a;
+    }
+    function g() public returns (uint x) {
+        x = 1;
+        uint a;
+        while (a < 10) {
+            return x;
+            x = x + x;
+            a = a + 1;
+        }
+        x = x + a;
+    }
+    function h() public returns (uint x) {
+        x = 1;
+        do {
+            x = x + 1;
+            return x;
+        } while (x < 3);
+    }
+}
+// ====
+// compileViaYul: true
+// ----
+// f() -> 1
+// g() -> 1
+// h() -> 2

test/libsolidity/semanticTests/viaYul/loops/simple.sol

@@ -7,34 +7,33 @@ contract C {
     }
     function g() public returns (uint x) {
         x = 1;
-        for (uint a = 0; a < 10; a = a + 1) {
+        uint a = 0;
+        while (a < 10) {
             x = x + x;
-            break;
+            a = a + 1;
         }
     }
     function h() public returns (uint x) {
         x = 1;
-        uint a = 0;
-        for (; a < 10; a = a + 1) {
-            continue;
-            x = x + x;
-        }
-        x = x + a;
+        do {
+            x = x + 1;
+        } while (false);
     }
     function i() public returns (uint x) {
         x = 1;
-        uint a;
-        for (; a < 10; a = a + 1) {
-            return x;
-            x = x + x;
-        }
-        x = x + a;
+        do {
+            x = x + 1;
+        } while (x < 3);
+    }
+    function j() public {
+        for (;;) {break;}
     }
 }
-// ===
+// ====
 // compileViaYul: true
 // ----
 // f() -> 1024
-// g() -> 2
-// h() -> 11
-// i() -> 1
+// g() -> 1024
+// h() -> 2
+// i() -> 3
+// j() ->