Merge pull request #130 from LefterisJP/dynamic_array_push

Dynamic array push

libsolidity/ExpressionCompiler.cpp

@@ -623,6 +623,44 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 			appendExternalFunctionCall(function, arguments);
 			break;
 		}
+		case Location::ByteArrayPush:
+		case Location::ArrayPush:
+		{
+			_functionCall.expression().accept(*this);
+			solAssert(function.parameterTypes().size() == 1, "");
+			solAssert(!!function.parameterTypes()[0], "");
+			TypePointer const& paramType = function.parameterTypes()[0];
+			shared_ptr<ArrayType> arrayType =
+				function.location() == Location::ArrayPush ?
+				make_shared<ArrayType>(DataLocation::Storage, paramType) :
+				make_shared<ArrayType>(DataLocation::Storage);
+			// get the current length
+			ArrayUtils(m_context).retrieveLength(*arrayType);
+			m_context << eth::Instruction::DUP1;
+			// stack: ArrayReference currentLength currentLength
+			m_context << u256(1) << eth::Instruction::ADD;
+			// stack: ArrayReference currentLength newLength
+			m_context << eth::Instruction::DUP3 << eth::Instruction::DUP2;
+			ArrayUtils(m_context).resizeDynamicArray(*arrayType);
+			m_context << eth::Instruction::SWAP2 << eth::Instruction::SWAP1;
+			// stack: newLength ArrayReference oldLength
+			ArrayUtils(m_context).accessIndex(*arrayType, false);
+
+			// stack: newLength storageSlot slotOffset
+			arguments[0]->accept(*this);
+			// stack: newLength storageSlot slotOffset argValue
+			TypePointer type = arguments[0]->annotation().type;
+			utils().convertType(*type, *arrayType->baseType());
+			type = arrayType->baseType();
+			utils().moveToStackTop(1 + type->sizeOnStack());
+			utils().moveToStackTop(1 + type->sizeOnStack());
+			// stack: newLength argValue storageSlot slotOffset
+			if (function.location() == Location::ArrayPush)
+				StorageItem(m_context, *paramType).storeValue(*type, _functionCall.location(), true);
+			else
+				StorageByteArrayElement(m_context).storeValue(*type, _functionCall.location(), true);
+			break;
+		}
 		default:
 			BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid function type."));
 		}
@@ -784,26 +822,37 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 	}
 	case Type::Category::Array:
 	{
-		solAssert(member == "length", "Illegal array member.");
 		auto const& type = dynamic_cast<ArrayType const&>(*_memberAccess.expression().annotation().type);
-		if (!type.isDynamicallySized())
+		if (member == "length")
 		{
-			utils().popStackElement(type);
-			m_context << type.length();
+			if (!type.isDynamicallySized())
+			{
+				utils().popStackElement(type);
+				m_context << type.length();
+			}
+			else
+				switch (type.location())
+				{
+				case DataLocation::CallData:
+					m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
+					break;
+				case DataLocation::Storage:
+					setLValue<StorageArrayLength>(_memberAccess, type);
+					break;
+				case DataLocation::Memory:
+					m_context << eth::Instruction::MLOAD;
+					break;
+				}
+		}
+		else if (member == "push")
+		{
+			solAssert(
+				type.isDynamicallySized() && type.location() == DataLocation::Storage,
+				"Tried to use .push() on a non-dynamically sized array"
+			);
 		}
 		else
-			switch (type.location())
-			{
-			case DataLocation::CallData:
-				m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
-				break;
-			case DataLocation::Storage:
-				setLValue<StorageArrayLength>(_memberAccess, type);
-				break;
-			case DataLocation::Memory:
-				m_context << eth::Instruction::MLOAD;
-				break;
-			}
+			solAssert(false, "Illegal array member.");
 		break;
 	}
 	default:

libsolidity/Types.cpp

@@ -858,6 +858,28 @@ string ArrayType::canonicalName(bool _addDataLocation) const
 	return ret;
 }
 
+MemberList const& ArrayType::members() const
+{
+	if (!m_members)
+	{
+		MemberList::MemberMap members;
+		if (!isString())
+		{
+			members.push_back({"length", make_shared<IntegerType>(256)});
+			if (isDynamicallySized() && location() == DataLocation::Storage)
+				members.push_back({"push", make_shared<FunctionType>(
+					TypePointers{baseType()},
+					TypePointers{make_shared<IntegerType>(256)},
+					strings{string()},
+					strings{string()},
+					isByteArray() ? FunctionType::Location::ByteArrayPush : FunctionType::Location::ArrayPush
+				)});
+		}
+		m_members.reset(new MemberList(members));
+	}
+	return *m_members;
+}
+
 TypePointer ArrayType::encodingType() const
 {
 	if (location() == DataLocation::Storage)
@@ -913,8 +935,6 @@ TypePointer ArrayType::copyForLocation(DataLocation _location, bool _isPointer)
 	return copy;
 }
 
-const MemberList ArrayType::s_arrayTypeMemberList({{"length", make_shared<IntegerType>(256)}});
-
 bool ContractType::operator==(Type const& _other) const
 {
 	if (_other.category() != category())
@@ -1422,6 +1442,8 @@ unsigned FunctionType::sizeOnStack() const
 		size = 1;
 	else if (location == Location::Internal)
 		size = 1;
+	else if (location == Location::ArrayPush || location == Location::ByteArrayPush)
+		size = 1;
 	if (m_gasSet)
 		size++;
 	if (m_valueSet)

libsolidity/Types.h

@@ -505,10 +505,7 @@ public:
 	virtual unsigned sizeOnStack() const override;
 	virtual std::string toString(bool _short) const override;
 	virtual std::string canonicalName(bool _addDataLocation) const override;
-	virtual MemberList const& members() const override
-	{
-		return isString() ? EmptyMemberList : s_arrayTypeMemberList;
-	}
+	virtual MemberList const& members() const override;
 	virtual TypePointer encodingType() const override;
 	virtual TypePointer decodingType() const override;
 	virtual TypePointer interfaceType(bool _inLibrary) const override;
@@ -532,7 +529,8 @@ private:
 	TypePointer m_baseType;
 	bool m_hasDynamicLength = true;
 	u256 m_length;
-	static const MemberList s_arrayTypeMemberList;
+	/// List of member types, will be lazy-initialized because of recursive references.
+	mutable std::unique_ptr<MemberList> m_members;
 };
 
 /**
@@ -736,7 +734,9 @@ public:
 		Event, ///< syntactic sugar for LOG*
 		SetGas, ///< modify the default gas value for the function call
 		SetValue, ///< modify the default value transfer for the function call
-		BlockHash ///< BLOCKHASH
+		BlockHash, ///< BLOCKHASH
+		ArrayPush, ///< .push() to a dynamically sized array in storage
+		ByteArrayPush ///< .push() to a dynamically sized byte array in storage
 	};
 
 	virtual Category category() const override { return Category::Function; }