Syntax for meta type information.

4 files changed, 53 insertions, 2 deletions

diff --git a/libsolidity/analysis/GlobalContext.cpp b/libsolidity/analysis/GlobalContext.cpp
index cd5fe07d..2276d783 100644
--- a/libsolidity/analysis/GlobalContext.cpp
+++ b/libsolidity/analysis/GlobalContext.cpp
@@ -61,7 +61,14 @@ m_magicVariables(vector<shared_ptr<MagicVariableDeclaration const>>{
 	make_shared<MagicVariableDeclaration>("sha256", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bytes32"}, FunctionType::Kind::SHA256, false, StateMutability::Pure)),
 	make_shared<MagicVariableDeclaration>("sha3", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bytes32"}, FunctionType::Kind::KECCAK256, false, StateMutability::Pure)),
 	make_shared<MagicVariableDeclaration>("suicide", make_shared<FunctionType>(strings{"address payable"}, strings{}, FunctionType::Kind::Selfdestruct)),
-	make_shared<MagicVariableDeclaration>("tx", make_shared<MagicType>(MagicType::Kind::Transaction))
+	make_shared<MagicVariableDeclaration>("tx", make_shared<MagicType>(MagicType::Kind::Transaction)),
+	make_shared<MagicVariableDeclaration>("type", make_shared<FunctionType>(
+		strings{"address"} /* accepts any contract type, handled by the type checker */,
+		strings{} /* returns a MagicType, handled by the type checker */,
+		FunctionType::Kind::MetaType,
+		false,
+		StateMutability::Pure
+	)),
 })
 {
 }
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 507a2c94..4cdfcc0c 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -199,6 +199,38 @@ TypePointers TypeChecker::typeCheckABIDecodeAndRetrieveReturnType(FunctionCall c
 	return components;
 }
 
+TypePointers TypeChecker::typeCheckMetaTypeFunctionAndRetrieveReturnType(FunctionCall const& _functionCall)
+{
+	vector<ASTPointer<Expression const>> arguments = _functionCall.arguments();
+	if (arguments.size() != 1)
+	{
+		m_errorReporter.typeError(
+			_functionCall.location(),
+			"This function takes one argument, but " +
+			toString(arguments.size()) +
+			" were provided."
+		);
+		return {};
+	}
+	TypePointer firstArgType = type(*arguments.front());
+	if (
+		firstArgType->category() != Type::Category::TypeType ||
+		dynamic_cast<TypeType const&>(*firstArgType).actualType()->category() != TypeType::Category::Contract
+	)
+	{
+		m_errorReporter.typeError(
+			arguments.front()->location(),
+			"Invalid type for argument in function call. "
+			"Contract type required, but " +
+			type(*arguments.front())->toString(true) +
+			" provided."
+		);
+		return {};
+	}
+
+	return {MagicType::metaType(dynamic_cast<TypeType const&>(*firstArgType).actualType())};
+}
+
 void TypeChecker::endVisit(InheritanceSpecifier const& _inheritance)
 {
 	auto base = dynamic_cast<ContractDefinition const*>(&dereference(_inheritance.name()));
@@ -1822,6 +1854,9 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
 			returnTypes = functionType->returnParameterTypes();
 			break;
 		}
+		case FunctionType::Kind::MetaType:
+			returnTypes = typeCheckMetaTypeFunctionAndRetrieveReturnType(_functionCall);
+			break;
 		default:
 		{
 			typeCheckFunctionCall(_functionCall, functionType);
@@ -2062,8 +2097,13 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 		if (tt->actualType()->category() == Type::Category::Enum)
 			annotation.isPure = true;
 	if (auto magicType = dynamic_cast<MagicType const*>(exprType.get()))
+	{
 		if (magicType->kind() == MagicType::Kind::ABI)
 			annotation.isPure = true;
+		else if (magicType->kind() == MagicType::Kind::MetaType)
+			if (memberName == "creationCode" || memberName == "runtimeCode")
+				annotation.isPure = true;
+	}
 
 	return false;
 }
diff --git a/libsolidity/analysis/TypeChecker.h b/libsolidity/analysis/TypeChecker.h
index b60c571a..d5f3645c 100644
--- a/libsolidity/analysis/TypeChecker.h
+++ b/libsolidity/analysis/TypeChecker.h
@@ -81,6 +81,8 @@ private:
 		bool _abiEncoderV2
 	);
 
+	TypePointers typeCheckMetaTypeFunctionAndRetrieveReturnType(FunctionCall const& _functionCall);
+
 	/// Performs type checks and determines result types for type conversion FunctionCall nodes.
 	TypePointer typeCheckTypeConversionAndRetrieveReturnType(
 		FunctionCall const& _functionCall
diff --git a/libsolidity/analysis/ViewPureChecker.cpp b/libsolidity/analysis/ViewPureChecker.cpp
index eb019481..7df7ac17 100644
--- a/libsolidity/analysis/ViewPureChecker.cpp
+++ b/libsolidity/analysis/ViewPureChecker.cpp
@@ -338,7 +338,9 @@ void ViewPureChecker::endVisit(MemberAccess const& _memberAccess)
 			{MagicType::Kind::ABI, "encodeWithSignature"},
 			{MagicType::Kind::Block, "blockhash"},
 			{MagicType::Kind::Message, "data"},
-			{MagicType::Kind::Message, "sig"}
+			{MagicType::Kind::Message, "sig"},
+			{MagicType::Kind::MetaType, "creationCode"},
+			{MagicType::Kind::MetaType, "runtimeCode"}
 		};
 		set<MagicMember> static const payableMembers{
 			{MagicType::Kind::Message, "value"}