From 9ecd51c54ddfce89bcc0daee7a7d7dd3f8e42784 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Thu, 5 Sep 2019 23:35:31 +0200
Subject: [PATCH] Refactor.

---
 libsolidity/codegen/CompilerUtils.cpp      | 20 ++++++++++++++++++++
 libsolidity/codegen/CompilerUtils.h        |  4 ++++
 libsolidity/codegen/ExpressionCompiler.cpp | 19 +------------------
 3 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index dfeb28db2..540a4f14e 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -95,6 +95,26 @@ void CompilerUtils::revertWithStringData(Type const& _argumentType)
 	m_context << Instruction::REVERT;
 }
 
+void CompilerUtils::returnDataToArray()
+{
+	if (m_context.evmVersion().supportsReturndata())
+	{
+		m_context << Instruction::RETURNDATASIZE;
+		m_context.appendInlineAssembly(R"({
+			switch v case 0 {
+				v := 0x60
+			} default {
+				v := mload(0x40)
+				mstore(0x40, add(v, and(add(returndatasize(), 0x3f), not(0x1f))))
+				mstore(v, returndatasize())
+				returndatacopy(add(v, 0x20), 0, returndatasize())
+			}
+		})", {"v"});
+	}
+	else
+		pushZeroPointer();
+}
+
 void CompilerUtils::accessCalldataTail(Type const& _type)
 {
 	solAssert(_type.dataStoredIn(DataLocation::CallData), "");
diff --git a/libsolidity/codegen/CompilerUtils.h b/libsolidity/codegen/CompilerUtils.h
index 8c9f1dc43..90ea8a156 100644
--- a/libsolidity/codegen/CompilerUtils.h
+++ b/libsolidity/codegen/CompilerUtils.h
@@ -67,6 +67,10 @@ public:
 	/// Stack post:
 	void revertWithStringData(Type const& _argumentType);
 
+	/// Allocates a new array and copies the return data to it.
+	/// If the EVM does not support return data, creates an empty array.
+	void returnDataToArray();
+
 	/// Computes the absolute calldata offset of a tail given a base reference and the (absolute)
 	/// offset of the tail pointer. Performs bounds checks. If @a _type is a dynamically sized array it also
 	/// returns the array length on the stack.
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 57a0cb189..bc4a6de8e 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -2189,24 +2189,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
 		// an internal helper function e.g. for ``send`` and ``transfer``. In that
 		// case we're only interested in the success condition, not the return data.
 		if (!_functionType.returnParameterTypes().empty())
-		{
-			if (haveReturndatacopy)
-			{
-				m_context << Instruction::RETURNDATASIZE;
-				m_context.appendInlineAssembly(R"({
-					switch v case 0 {
-						v := 0x60
-					} default {
-						v := mload(0x40)
-						mstore(0x40, add(v, and(add(returndatasize(), 0x3f), not(0x1f))))
-						mstore(v, returndatasize())
-						returndatacopy(add(v, 0x20), 0, returndatasize())
-					}
-				})", {"v"});
-			}
-			else
-				utils().pushZeroPointer();
-		}
+			utils().returnDataToArray();
 	}
 	else if (funKind == FunctionType::Kind::RIPEMD160)
 	{