Unpacking of dynamically sized arguments.

libsolidity/Compiler.cpp

@@ -178,15 +178,40 @@ void Compiler::appendFunctionSelector(ContractDefinition const& _contract)
 	}
 }
 
-unsigned Compiler::appendCalldataUnpacker(TypePointers const& _typeParameters, bool _fromMemory)
+void Compiler::appendCalldataUnpacker(TypePointers const& _typeParameters, bool _fromMemory)
 {
 	// We do not check the calldata size, everything is zero-padded.
-	unsigned dataOffset = CompilerUtils::dataStartOffset; // the 4 bytes of the function hash signature
-
+	unsigned offset(CompilerUtils::dataStartOffset);
 	bool const c_padToWords = true;
+
+	unsigned dynamicParameterCount = 0;
 	for (TypePointer const& type: _typeParameters)
-		dataOffset += CompilerUtils(m_context).loadFromMemory(dataOffset, *type, !_fromMemory, c_padToWords);
-	return dataOffset;
+		if (type->isDynamicallySized())
+			dynamicParameterCount++;
+	offset += dynamicParameterCount * 32;
+	unsigned currentDynamicParameter = 0;
+	for (TypePointer const& type: _typeParameters)
+		if (type->isDynamicallySized())
+		{
+			// value on stack: [memory_offset] (only if we are already in dynamic mode)
+			if (currentDynamicParameter == 0)
+				// switch from static to dynamic
+				m_context << u256(offset);
+			CompilerUtils(m_context).loadFromMemory(
+				CompilerUtils::dataStartOffset + currentDynamicParameter * 32,
+				IntegerType(256), !_fromMemory, c_padToWords);
+			// store new memory pointer
+			m_context << eth::Instruction::DUP2 << eth::Instruction::DUP2 << eth::Instruction::ADD;
+			currentDynamicParameter++;
+			// value on stack: offset length next_memory_offset
+		}
+		else if (currentDynamicParameter == 0)
+			// we can still use static load
+			offset += CompilerUtils(m_context).loadFromMemory(offset, *type, !_fromMemory, c_padToWords);
+		else
+			CompilerUtils(m_context).loadFromMemoryDynamic(*type, !_fromMemory, c_padToWords);
+	if (dynamicParameterCount > 0)
+		m_context << eth::Instruction::POP;
 }
 
 void Compiler::appendReturnValuePacker(TypePointers const& _typeParameters)

libsolidity/Compiler.h

@@ -52,8 +52,8 @@ private:
 	void appendConstructorCall(FunctionDefinition const& _constructor);
 	void appendFunctionSelector(ContractDefinition const& _contract);
 	/// Creates code that unpacks the arguments for the given function represented by a vector of TypePointers.
-	/// From memory if @a _fromMemory is true, otherwise from call data. @returns the size of the data in bytes.
-	unsigned appendCalldataUnpacker(TypePointers const& _typeParameters, bool _fromMemory = false);
+	/// From memory if @a _fromMemory is true, otherwise from call data.
+	void appendCalldataUnpacker(TypePointers const& _typeParameters, bool _fromMemory = false);
 	void appendReturnValuePacker(TypePointers const& _typeParameters);
 
 	void registerStateVariables(ContractDefinition const& _contract);

libsolidity/Types.h

@@ -122,6 +122,8 @@ public:
 	/// is not a simple big-endian encoding or the type cannot be stored in calldata.
 	/// Note that irrespective of this size, each calldata element is padded to a multiple of 32 bytes.
 	virtual unsigned getCalldataEncodedSize() const { return 0; }
+	/// @returns true if the type is dynamically encoded in calldata
+	virtual bool isDynamicallySized() const { return false; }
 	/// @returns number of bytes required to hold this value in storage.
 	/// For dynamically "allocated" types, it returns the size of the statically allocated head,
 	virtual u256 getStorageSize() const { return 1; }
@@ -289,6 +291,7 @@ public:
 	virtual bool isImplicitlyConvertibleTo(Type const& _convertTo) const override;
 	virtual TypePointer unaryOperatorResult(Token::Value _operator) const override;
 	virtual bool operator==(const Type& _other) const override;
+	virtual bool isDynamicallySized() const { return true; }
 	virtual unsigned getSizeOnStack() const override;
 	virtual std::string toString() const override { return "bytes"; }
 	virtual MemberList const& getMembers() const override { return s_byteArrayMemberList; }