Merge pull request #1630 from ethereum/function-to-address

Explicit external function type to address conversion

2 files changed, 15 insertions, 1 deletions

diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index 477f021a..9f019d27 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -787,6 +787,20 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
 		if (_cleanupNeeded)
 			m_context << Instruction::ISZERO << Instruction::ISZERO;
 		break;
+	case Type::Category::Function:
+	{
+		if (targetTypeCategory == Type::Category::Integer)
+		{
+			IntegerType const& targetType = dynamic_cast<IntegerType const&>(_targetType);
+			solAssert(targetType.isAddress(), "Function type can only be converted to address.");
+			FunctionType const& typeOnStack = dynamic_cast<FunctionType const&>(_typeOnStack);
+			solAssert(typeOnStack.location() == FunctionType::Location::External, "Only external function type can be converted.");
+
+			// stack: <address> <function_id>
+			m_context << Instruction::POP;
+			break;
+		}
+	}
 	default:
 		// All other types should not be convertible to non-equal types.
 		solAssert(_typeOnStack == _targetType, "Invalid type conversion requested.");
diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp
index 4d33927d..9d6129a3 100644
--- a/libsolidity/codegen/ContractCompiler.cpp
+++ b/libsolidity/codegen/ContractCompiler.cpp
@@ -42,7 +42,7 @@ class StackHeightChecker
 public:
 	StackHeightChecker(CompilerContext const& _context):
 		m_context(_context), stackHeight(m_context.stackHeight()) {}
-	void check() { solAssert(m_context.stackHeight() == stackHeight, "I sense a disturbance in the stack."); }
+	void check() { solAssert(m_context.stackHeight() == stackHeight, std::string("I sense a disturbance in the stack: ") + std::to_string(m_context.stackHeight()) + " vs " + std::to_string(stackHeight)); }
 private:
 	CompilerContext const& m_context;
 	unsigned stackHeight;