Merge pull request #4522 from ethereum/fullEncodingType

Isolate determining the encoding type into its own function.

2 files changed, 26 insertions, 0 deletions

diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index c85e0522..0954fdf3 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -390,6 +390,27 @@ MemberList const& Type::members(ContractDefinition const* _currentScope) const
 	return *m_members[_currentScope];
 }
 
+TypePointer Type::fullEncodingType(bool _inLibraryCall, bool _encoderV2, bool _packed) const
+{
+	TypePointer encodingType = mobileType();
+	if (encodingType)
+		encodingType = encodingType->interfaceType(_inLibraryCall);
+	if (encodingType)
+		encodingType = encodingType->encodingType();
+	if (auto structType = dynamic_cast<StructType const*>(encodingType.get()))
+	{
+		// Structs are fine in the following circumstances:
+		// - ABIv2 without packed encoding or,
+		// - storage struct for a library
+		if (!(
+			(_encoderV2 && !_packed) ||
+			(structType->location() == DataLocation::Storage && _inLibraryCall)
+		))
+			return TypePointer();
+	}
+	return encodingType;
+}
+
 MemberList::MemberMap Type::boundFunctions(Type const& _type, ContractDefinition const& _scope)
 {
 	// Normalise data location of type.
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index 474a6f33..12029a4e 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -280,6 +280,11 @@ public:
 	/// This for example returns address for contract types.
 	/// If there is no such type, returns an empty shared pointer.
 	virtual TypePointer encodingType() const { return TypePointer(); }
+	/// @returns the encoding type used under the given circumstances for the type of an expression
+	/// when used for e.g. abi.encode(...) or the empty pointer if the object
+	/// cannot be encoded.
+	/// This is different from encodingType since it takes implicit conversions into account.
+	TypePointer fullEncodingType(bool _inLibraryCall, bool _encoderV2, bool _packed) const;
 	/// @returns a (simpler) type that is used when decoding this type in calldata.
 	virtual TypePointer decodingType() const { return encodingType(); }
 	/// @returns a type that will be used outside of Solidity for e.g. function signatures.