Implement uninitialized storage functions.

4 files changed, 19 insertions, 14 deletions

diff --git a/libevmasm/Assembly.cpp b/libevmasm/Assembly.cpp
index e881c1e2..e19b6b0d 100644
--- a/libevmasm/Assembly.cpp
+++ b/libevmasm/Assembly.cpp
@@ -485,6 +485,7 @@ LinkerObject const& Assembly::assemble() const
 			break;
 		case Tag:
 			tagPos[(unsigned)i.data()] = ret.bytecode.size();
+			assertThrow(ret.bytecode.size() < 0xffffffffL, AssemblyException, "Tag too large.");
 			assertThrow(i.data() != 0, AssemblyException, "");
 			ret.bytecode.push_back((byte)Instruction::JUMPDEST);
 			break;
diff --git a/libsolidity/codegen/CompilerContext.h b/libsolidity/codegen/CompilerContext.h
index 0c1500b0..6c509685 100644
--- a/libsolidity/codegen/CompilerContext.h
+++ b/libsolidity/codegen/CompilerContext.h
@@ -44,6 +44,8 @@ namespace solidity {
 class CompilerContext
 {
 public:
+	bool isCreationPhase() const { return m_mode == CompilationMode::Creation; }
+
 	void addMagicGlobal(MagicVariableDeclaration const& _declaration);
 	void addStateVariable(VariableDeclaration const& _declaration, u256 const& _storageOffset, unsigned _byteOffset);
 	void addVariable(VariableDeclaration const& _declaration, unsigned _offsetToCurrent = 0);
diff --git a/libsolidity/codegen/LValue.cpp b/libsolidity/codegen/LValue.cpp
index d2c75445..66449fc4 100644
--- a/libsolidity/codegen/LValue.cpp
+++ b/libsolidity/codegen/LValue.cpp
@@ -190,11 +190,11 @@ void StorageItem::retrieveValue(SourceLocation const&, bool _remove) const
 			dynamic_cast<IntegerType const&>(*m_dataType).isSigned()
 		)
 			m_context << u256(m_dataType->storageBytes() - 1) << Instruction::SIGNEXTEND;
-		else if (
-			m_dataType->category() == Type::Category::Function &&
-			dynamic_cast<FunctionType const&>(*m_dataType).location() == FunctionType::Location::External
-		)
-			CompilerUtils(m_context).splitExternalFunctionType(false);
+		else if (FunctionType const* fun = dynamic_cast<decltype(fun)>(m_dataType))
+		{
+			if (fun->location() == FunctionType::Location::External)
+				CompilerUtils(m_context).splitExternalFunctionType(false);
+		}
 		else
 		{
 			solAssert(m_dataType->sizeOnStack() == 1, "");
@@ -236,12 +236,16 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc
 			// stack: value storage_ref cleared_value multiplier
 			utils.copyToStackTop(3 + m_dataType->sizeOnStack(), m_dataType->sizeOnStack());
 			// stack: value storage_ref cleared_value multiplier value
-			if (
-				m_dataType->category() == Type::Category::Function &&
-				dynamic_cast<FunctionType const&>(*m_dataType).location() == FunctionType::Location::External
-			)
-				// Combine the two-item function type into a single stack slot.
-				utils.combineExternalFunctionType(false);
+			if (FunctionType const* fun = dynamic_cast<decltype(fun)>(m_dataType))
+			{
+				if (fun->location() == FunctionType::Location::External)
+					// Combine the two-item function type into a single stack slot.
+					utils.combineExternalFunctionType(false);
+				else
+					m_context <<
+						((u256(1) << (8 * m_dataType->storageBytes())) - 1) <<
+						Instruction::AND;
+			}
 			else if (m_dataType->category() == Type::Category::FixedBytes)
 				m_context
 					<< (u256(0x1) << (256 - 8 * dynamic_cast<FixedBytesType const&>(*m_dataType).numBytes()))
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 44dba9b2..c665b050 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -7631,8 +7631,6 @@ BOOST_AUTO_TEST_CASE(calling_uninitialized_function)
 
 BOOST_AUTO_TEST_CASE(calling_uninitialized_function_in_detail)
 {
-	// Storage default value of zero would be correct jump dest, this tests that
-	// that is properly handled.
 	char const* sourceCode = R"(
 		contract C {
 			function() internal returns (uint) x;
@@ -7641,7 +7639,7 @@ BOOST_AUTO_TEST_CASE(calling_uninitialized_function_in_detail)
 				if (mutex > 0)
 					return 7;
 				mutex = 1;
-				// If this test fails, it will jump to "0" and re-execute this function.
+				// Avoid re-executing this function if we jump somewhere.
 				x();
 				return 2;
 			}