Use "tuple" for struct types in ABI JSON.

Only use tuple as a type in the ABI (and remove all "anonymous struct" references too)

docs/abi-spec.rst

@@ -68,13 +68,12 @@ The following non-fixed-size types exist:
 
 - ``<type>[]``: a variable-length array of the given fixed-length type.
 
-Types can be combined to anonymous structs by enclosing a finite non-negative number
+Types can be combined to a tuple by enclosing a finite non-negative number
 of them inside parentheses, separated by commas:
 
-- ``(T1,T2,...,Tn)``: anonymous struct (ordered tuple) consisting of the types ``T1``, ..., ``Tn``, ``n >= 0``
+- ``(T1,T2,...,Tn)``: tuple consisting of the types ``T1``, ..., ``Tn``, ``n >= 0``
-
-It is possible to form structs of structs, arrays of structs and so on.
 
+It is possible to form tuples of tuples, arrays of tuples and so on.
 
 Formal Specification of the Encoding
 ====================================
@@ -133,7 +132,7 @@ on the type of ``X`` being
 
   ``enc(X) = enc((X[0], ..., X[k-1]))``
   
-  i.e. it is encoded as if it were an anonymous struct with ``k`` elements
+  i.e. it is encoded as if it were a tuple with ``k`` elements
   of the same type.
   
 - ``T[]`` where ``X`` has ``k`` elements (``k`` is assumed to be of type ``uint256``):
@@ -176,7 +175,7 @@ and the return values ``v_1, ..., v_k`` of ``f`` are encoded as
 
   ``enc((v_1, ..., v_k))``
 
-i.e. the values are combined into an anonymous struct and encoded.
+i.e. the values are combined into a tuple and encoded.
 
 Examples
 ========
@@ -357,16 +356,17 @@ would result in the JSON:
   "outputs": []
   }]
 
-Use of Structs in Types
+Handling tuple types
------------------------
+--------------------
 
-If structs are part of the type, we still want to know the name of the components. Because of that,
+If tuples are part of the type, we still want to know the name of the components. Because of that,
 the json structure gets arbitrarily nested in the following way:
 
 An object with members ``name``, ``type`` and potentially ``components`` describes a typed variable.
-The canonical type is determined until a struct type is reached and the string description up
+The canonical type is determined until a tuple type is reached and the string description up
-to that point is stored in ``type``, i.e. it will be a sequence of ``[]`` and ``[k]`` with
+to that point is stored in ``type`` prefix with the word ``tuple``, i.e. it will be ``tuple`` followed by
-integers ``k``. The components of the struct are then stored in the member ``components``,
+a sequence of ``[]`` and ``[k]`` with
+integers ``k``. The components of the tuple are then stored in the member ``components``,
 which is of array type and has the same structure as the top-level object except that
 ``indexed`` is not allowed there.
 
@@ -391,7 +391,7 @@ would result in the JSON:
       "inputs": [
         {
           "name": "s",
-          "type": "",
+          "type": "tuple",
           "components": [
             {
               "name": "a",
@@ -403,7 +403,7 @@ would result in the JSON:
             },
             {
               "name": "c",
-              "type": "[]",
+              "type": "tuple[]",
               "components": [
                 {
                   "name": "x",
@@ -419,7 +419,7 @@ would result in the JSON:
         },
         {
           "name": "t",
-          "type": "",
+          "type": "tuple",
           "components": [
             {
               "name": "x",

libsolidity/interface/ABI.cpp

@@ -147,7 +147,7 @@ Json::Value ABI::formatType(string const& _name, Type const& _type, bool _forLib
 	}
 	else if (StructType const* structType = dynamic_cast<StructType const*>(&_type))
 	{
-		ret["type"] = string();
+		ret["type"] = "tuple";
 		ret["components"] = Json::arrayValue;
 		for (auto const& member: structType->members(nullptr))
 		{

test/libsolidity/SolidityABIJSON.cpp

@@ -973,11 +973,11 @@ BOOST_AUTO_TEST_CASE(return_structs)
 						}
 					],
 					"name" : "sub",
-					"type" : "[]"
+					"type" : "tuple[]"
 				}
 			],
 			"name" : "s",
-			"type" : ""
+			"type" : "tuple"
 			}
 		],
 		"payable" : false,
@@ -1015,7 +1015,7 @@ BOOST_AUTO_TEST_CASE(return_structs_with_contracts)
 					}
 				],
 				"name": "s",
-				"type": ""
+				"type": "tuple"
 			},
 			{
 				"name": "c",
@@ -1052,7 +1052,7 @@ BOOST_AUTO_TEST_CASE(event_structs)
 				],
 				"indexed": false,
 				"name": "t",
-				"type": ""
+				"type": "tuple"
 			},
 			{
 				"components": [
@@ -1068,7 +1068,7 @@ BOOST_AUTO_TEST_CASE(event_structs)
 							}
 						],
 						"name": "sub",
-						"type": "[]"
+						"type": "tuple[]"
 					},
 					{
 						"name": "b",
@@ -1077,7 +1077,7 @@ BOOST_AUTO_TEST_CASE(event_structs)
 				],
 				"indexed": false,
 				"name": "s",
-				"type": ""
+				"type": "tuple"
 			}
 		],
 		"name": "E",
@@ -1115,7 +1115,7 @@ BOOST_AUTO_TEST_CASE(structs_in_libraries)
 							}
 						],
 						"name": "sub",
-						"type": "[]"
+						"type": "tuple[]"
 					},
 					{
 						"name": "b",
@@ -1123,7 +1123,7 @@ BOOST_AUTO_TEST_CASE(structs_in_libraries)
 					}
 				],
 				"name": "s",
-				"type": ""
+				"type": "tuple"
 			}
 		],
 		"name": "g",

test/libsolidity/SolidityNameAndTypeResolution.cpp

@@ -601,7 +601,6 @@ BOOST_AUTO_TEST_CASE(enum_external_type)
 
 BOOST_AUTO_TEST_CASE(external_structs)
 {
-	ASTPointer<SourceUnit> sourceUnit;
 	char const* text = R"(
 		contract Test {
 			enum ActionChoices { GoLeft, GoRight, GoStraight, Sit }
@@ -614,7 +613,7 @@ BOOST_AUTO_TEST_CASE(external_structs)
 			function i(Nested[]) external {}
 		}
 	)";
-	ETH_TEST_REQUIRE_NO_THROW(sourceUnit = parseAndAnalyse(text), "Parsing and name Resolving failed");
+	SourceUnit const* sourceUnit = parseAndAnalyse(text);
 	for (ASTPointer<ASTNode> const& node: sourceUnit->nodes())
 		if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
 		{
@@ -627,7 +626,33 @@ BOOST_AUTO_TEST_CASE(external_structs)
 		}
 }
 
-// TODO: Add a test that checks the signature of library functions taking structs
+BOOST_AUTO_TEST_CASE(external_structs_in_libraries)
+{
+	char const* text = R"(
+		library Test {
+			enum ActionChoices { GoLeft, GoRight, GoStraight, Sit }
+			struct Empty {}
+			struct Nested { X[2][] a; mapping(uint => uint) m; uint y; }
+			struct X { bytes32 x; Test t; Empty[] e; }
+			function f(ActionChoices, uint, Empty) external {}
+			function g(Test, Nested) external {}
+			function h(function(Nested) external returns (uint)[]) external {}
+			function i(Nested[]) external {}
+		}
+	)";
+	SourceUnit const* sourceUnit = parseAndAnalyse(text);
+	for (ASTPointer<ASTNode> const& node: sourceUnit->nodes())
+		if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
+		{
+			auto functions = contract->definedFunctions();
+			BOOST_REQUIRE(!functions.empty());
+			BOOST_CHECK_EQUAL("f(Test.ActionChoices,uint256,Test.Empty)", functions[0]->externalSignature());
+			BOOST_CHECK_EQUAL("g(Test,Test.Nested)", functions[1]->externalSignature());
+			BOOST_CHECK_EQUAL("h(function[])", functions[2]->externalSignature());
+			BOOST_CHECK_EQUAL("i(Test.Nested[])", functions[3]->externalSignature());
+		}
+}
+
 
 BOOST_AUTO_TEST_CASE(function_external_call_allowed_conversion)
 {