Merge pull request #4431 from ethereum/tupleDeclaration

Disallow multi variable declarations with mismatching number of values.

30 files changed, 205 insertions, 203 deletions

diff --git a/Changelog.md b/Changelog.md
index 094cdc0d..2127d9c5 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -38,6 +38,7 @@ Breaking Changes:
  * Type Checker: Disallow tight packing of literals. This was already the case in the experimental 0.5.0 mode.
  * Type Checker: Disallow conversions between ``bytesX`` and ``uintY`` of different size.
  * Type Checker: Disallow empty tuple components. This was partly already the case in the experimental 0.5.0 mode.
+ * Type Checker: Disallow multi-variable declarations with mismatching number of values. This was already the case in the experimental 0.5.0 mode.
  * Type Checker: Disallow specifying base constructor arguments multiple times in the same inheritance hierarchy. This was already the case in the experimental 0.5.0 mode.
  * Type Checker: Disallow calling constructor with wrong argument count. This was already the case in the experimental 0.5.0 mode.
  * Type Checker: Disallow uninitialized storage variables. This was already the case in the experimental 0.5.0 mode.
diff --git a/docs/control-structures.rst b/docs/control-structures.rst
index 50c401e2..837a0a90 100644
--- a/docs/control-structures.rst
+++ b/docs/control-structures.rst
@@ -297,9 +297,9 @@ These can then either be assigned to newly declared variables or to pre-existing
     }
 
 .. note::
-    Prior to version 0.4.24 it was possible to assign to tuples of smaller size, either
+    Prior to version 0.5.0 it was possible to assign to tuples of smaller size, either
     filling up on the left or on the right side (which ever was empty). This is
-    now deprecated, both sides have to have the same number of components.
+    now disallowed, so both sides have to have the same number of components.
 
 Complications for Arrays and Structs
 ------------------------------------
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 8ea0a4d7..e2e4d9c3 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1043,10 +1043,10 @@ namespace
  * @returns a suggested left-hand-side of a multi-variable declaration contairing
  * the variable declarations given in @a _decls.
  */
-string createTupleDecl(vector<VariableDeclaration const*> const& _decls)
+string createTupleDecl(vector<ASTPointer<VariableDeclaration>> const& _decls)
 {
 	vector<string> components;
-	for (VariableDeclaration const* decl: _decls)
+	for (ASTPointer<VariableDeclaration> const& decl: _decls)
 		if (decl)
 			components.emplace_back(decl->annotation().type->toString(false) + " " + decl->name());
 		else
@@ -1058,9 +1058,9 @@ string createTupleDecl(vector<VariableDeclaration const*> const& _decls)
 		return "(" + boost::algorithm::join(components, ", ") + ")";
 }
 
-bool typeCanBeExpressed(vector<VariableDeclaration const*> const& decls)
+bool typeCanBeExpressed(vector<ASTPointer<VariableDeclaration>> const& decls)
 {
-	for (VariableDeclaration const* decl: decls)
+	for (ASTPointer<VariableDeclaration> const& decl: decls)
 	{
 		// skip empty tuples (they can be expressed of course)
 		if (!decl)
@@ -1080,7 +1080,6 @@ bool typeCanBeExpressed(vector<VariableDeclaration const*> const& decls)
 
 bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 {
-	bool const v050 = m_scope->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050);
 	if (!_statement.initialValue())
 	{
 		// No initial value is only permitted for single variables with specified type.
@@ -1119,82 +1118,27 @@ bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 	else
 		valueTypes = TypePointers{type(*_statement.initialValue())};
 
-	// Determine which component is assigned to which variable.
-	// If numbers do not match, fill up if variables begin or end empty (not both).
-	vector<VariableDeclaration const*>& assignments = _statement.annotation().assignments;
-	assignments.resize(valueTypes.size(), nullptr);
 	vector<ASTPointer<VariableDeclaration>> const& variables = _statement.declarations();
 	if (variables.empty())
-	{
-		if (!valueTypes.empty())
-			m_errorReporter.fatalTypeError(
-				_statement.location(),
-				"Too many components (" +
-				toString(valueTypes.size()) +
-				") in value for variable assignment (0) needed"
-			);
-	}
+		// We already have an error for this in the SyntaxChecker.
+		solAssert(m_errorReporter.hasErrors(), "");
 	else if (valueTypes.size() != variables.size())
-	{
-		if (v050)
-			m_errorReporter.fatalTypeError(
-				_statement.location(),
-				"Different number of components on the left hand side (" +
-				toString(variables.size()) +
-				") than on the right hand side (" +
-				toString(valueTypes.size()) +
-				")."
-			);
-		else if (!variables.front() && !variables.back())
-			m_errorReporter.fatalTypeError(
-				_statement.location(),
-				"Wildcard both at beginning and end of variable declaration list is only allowed "
-				"if the number of components is equal."
-			);
-		else
-			m_errorReporter.warning(
-				_statement.location(),
-				"Different number of components on the left hand side (" +
-				toString(variables.size()) +
-				") than on the right hand side (" +
-				toString(valueTypes.size()) +
-				")."
-			);
-	}
-	size_t minNumValues = variables.size();
-	if (!variables.empty() && (!variables.back() || !variables.front()))
-		--minNumValues;
-	if (valueTypes.size() < minNumValues)
-		m_errorReporter.fatalTypeError(
-			_statement.location(),
-			"Not enough components (" +
-			toString(valueTypes.size()) +
-			") in value to assign all variables (" +
-			toString(minNumValues) + ")."
-		);
-	if (valueTypes.size() > variables.size() && variables.front() && variables.back())
-		m_errorReporter.fatalTypeError(
+		m_errorReporter.typeError(
 			_statement.location(),
-			"Too many components (" +
+			"Different number of components on the left hand side (" +
+			toString(variables.size()) +
+			") than on the right hand side (" +
 			toString(valueTypes.size()) +
-			") in value for variable assignment (" +
-			toString(minNumValues) +
-			" needed)."
+			")."
 		);
-	bool fillRight = !variables.empty() && (!variables.back() || variables.front());
-	for (size_t i = 0; i < min(variables.size(), valueTypes.size()); ++i)
-		if (fillRight)
-			assignments[i] = variables[i].get();
-		else
-			assignments[assignments.size() - i - 1] = variables[variables.size() - i - 1].get();
 
 	bool autoTypeDeductionNeeded = false;
 
-	for (size_t i = 0; i < assignments.size(); ++i)
+	for (size_t i = 0; i < min(variables.size(), valueTypes.size()); ++i)
 	{
-		if (!assignments[i])
+		if (!variables[i])
 			continue;
-		VariableDeclaration const& var = *assignments[i];
+		VariableDeclaration const& var = *variables[i];
 		solAssert(!var.value(), "Value has to be tied to statement.");
 		TypePointer const& valueComponentType = valueTypes[i];
 		solAssert(!!valueComponentType, "");
@@ -1284,7 +1228,7 @@ bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 
 	if (autoTypeDeductionNeeded)
 	{
-		if (!typeCanBeExpressed(assignments))
+		if (!typeCanBeExpressed(variables))
 			m_errorReporter.syntaxError(
 				_statement.location(),
 				"Use of the \"var\" keyword is disallowed. "
@@ -1294,7 +1238,7 @@ bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 			m_errorReporter.syntaxError(
 				_statement.location(),
 				"Use of the \"var\" keyword is disallowed. "
-				"Use explicit declaration `" + createTupleDecl(assignments) + " = ...´ instead."
+				"Use explicit declaration `" + createTupleDecl(variables) + " = ...´ instead."
 			);
 	}
 
diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index 16c9b2d2..7719d080 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -535,13 +535,6 @@ ReturnAnnotation& Return::annotation() const
 	return dynamic_cast<ReturnAnnotation&>(*m_annotation);
 }
 
-VariableDeclarationStatementAnnotation& VariableDeclarationStatement::annotation() const
-{
-	if (!m_annotation)
-		m_annotation = new VariableDeclarationStatementAnnotation();
-	return dynamic_cast<VariableDeclarationStatementAnnotation&>(*m_annotation);
-}
-
 ExpressionAnnotation& Expression::annotation() const
 {
 	if (!m_annotation)
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index e862fd62..acd90ad8 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -1270,8 +1270,6 @@ public:
 	virtual void accept(ASTVisitor& _visitor) override;
 	virtual void accept(ASTConstVisitor& _visitor) const override;
 
-	VariableDeclarationStatementAnnotation& annotation() const override;
-
 	std::vector<ASTPointer<VariableDeclaration>> const& declarations() const { return m_variables; }
 	Expression const* initialValue() const { return m_initialValue.get(); }
 
diff --git a/libsolidity/ast/ASTAnnotations.h b/libsolidity/ast/ASTAnnotations.h
index 5cbe42bd..e0b3f492 100644
--- a/libsolidity/ast/ASTAnnotations.h
+++ b/libsolidity/ast/ASTAnnotations.h
@@ -164,13 +164,6 @@ struct UserDefinedTypeNameAnnotation: TypeNameAnnotation
 	ContractDefinition const* contractScope = nullptr;
 };
 
-struct VariableDeclarationStatementAnnotation: StatementAnnotation
-{
-	/// Information about which component of the value is assigned to which variable.
-	/// The pointer can be null to signify that the component is discarded.
-	std::vector<VariableDeclaration const*> assignments;
-};
-
 struct ExpressionAnnotation: ASTAnnotation
 {
 	/// Inferred type of the expression.
diff --git a/libsolidity/ast/ASTJsonConverter.cpp b/libsolidity/ast/ASTJsonConverter.cpp
index b7855668..a26828a6 100644
--- a/libsolidity/ast/ASTJsonConverter.cpp
+++ b/libsolidity/ast/ASTJsonConverter.cpp
@@ -555,8 +555,8 @@ bool ASTJsonConverter::visit(EmitStatement const& _node)
 bool ASTJsonConverter::visit(VariableDeclarationStatement const& _node)
 {
 	Json::Value varDecs(Json::arrayValue);
-	for (auto const& v: _node.annotation().assignments)
-		appendMove(varDecs, idOrNull(v));
+	for (auto const& v: _node.declarations())
+		appendMove(varDecs, idOrNull(v.get()));
 	setJsonNode(_node, "VariableDeclarationStatement", {
 		make_pair("assignments", std::move(varDecs)),
 		make_pair("declarations", toJson(_node.declarations())),
diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp
index 93f698bc..bbb3db3d 100644
--- a/libsolidity/codegen/ContractCompiler.cpp
+++ b/libsolidity/codegen/ContractCompiler.cpp
@@ -833,20 +833,19 @@ bool ContractCompiler::visit(VariableDeclarationStatement const& _variableDeclar
 			valueTypes = tupleType->components();
 		else
 			valueTypes = TypePointers{expression->annotation().type};
-		auto const& assignments = _variableDeclarationStatement.annotation().assignments;
-		solAssert(assignments.size() == valueTypes.size(), "");
-		for (size_t i = 0; i < assignments.size(); ++i)
+		auto const& declarations = _variableDeclarationStatement.declarations();
+		solAssert(declarations.size() == valueTypes.size(), "");
+		for (size_t i = 0; i < declarations.size(); ++i)
 		{
-			size_t j = assignments.size() - i - 1;
+			size_t j = declarations.size() - i - 1;
 			solAssert(!!valueTypes[j], "");
-			VariableDeclaration const* varDecl = assignments[j];
-			if (!varDecl)
-				utils.popStackElement(*valueTypes[j]);
-			else
+			if (VariableDeclaration const* varDecl = declarations[j].get())
 			{
 				utils.convertType(*valueTypes[j], *varDecl->annotation().type);
 				utils.moveToStackVariable(*varDecl);
 			}
+			else
+				utils.popStackElement(*valueTypes[j]);
 		}
 	}
 	checker.check();
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index ad425d98..bee83007 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -8091,17 +8091,36 @@ BOOST_AUTO_TEST_CASE(multi_variable_declaration)
 			function g() public returns (uint a, uint b, uint c) {
 				a = 1; b = 2; c = 3;
 			}
-			function f() public returns (bool) {
+			function h() public returns (uint a, uint b, uint c, uint d) {
+				a = 1; b = 2; c = 3; d = 4;
+			}
+			function f1() public returns (bool) {
 				(uint x, uint y, uint z) = g();
 				if (x != 1 || y != 2 || z != 3) return false;
 				(, uint a,) = g();
 				if (a != 2) return false;
-				(uint b,) = g();
+				(uint b, , ) = g();
 				if (b != 1) return false;
-				(, uint c) = g();
+				(, , uint c) = g();
 				if (c != 3) return false;
 				return true;
 			}
+			function f2() public returns (bool) {
+				(uint a1, , uint a3, ) = h();
+				if (a1 != 1 || a3 != 3) return false;
+				(uint b1, uint b2, , ) = h();
+				if (b1 != 1 || b2 != 2) return false;
+				(, uint c2, uint c3, ) = h();
+				if (c2 != 2 || c3 != 3) return false;
+				(, , uint d3, uint d4) = h();
+				if (d3 != 3 || d4 != 4) return false;
+				(uint e1, , uint e3, uint e4) = h();
+				if (e1 != 1 || e3 != 3 || e4 != 4) return false;
+				return true;
+			}
+			function f() public returns (bool) {
+				return f1() && f2();
+			}
 		}
 	)";
 	compileAndRun(sourceCode);
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/differentNumberOfComponents.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/differentNumberOfComponents.sol
new file mode 100644
index 00000000..3b05a54c
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/differentNumberOfComponents.sol
@@ -0,0 +1,25 @@
+contract C {
+    function f() public {
+        uint a = (1,2);
+        uint b = (1,2,3);
+        uint c = (1,2,3,4);
+    }
+    function g() public {
+        (uint a1, uint b1, uint c1, uint d1) = 1;
+        (uint a2, uint b2, uint c2) = 1;
+        (uint a3, uint b3) = 1;
+    }
+    function h() public {
+        (uint a1, uint b1, uint c1, uint d1) = (1,2,3);
+        (uint a2, uint b2, uint c2) = (1,2,3,4);
+    }
+}
+// ----
+// TypeError: (47-61): Different number of components on the left hand side (1) than on the right hand side (2).
+// TypeError: (71-87): Different number of components on the left hand side (1) than on the right hand side (3).
+// TypeError: (97-115): Different number of components on the left hand side (1) than on the right hand side (4).
+// TypeError: (157-197): Different number of components on the left hand side (4) than on the right hand side (1).
+// TypeError: (207-238): Different number of components on the left hand side (3) than on the right hand side (1).
+// TypeError: (248-270): Different number of components on the left hand side (2) than on the right hand side (1).
+// TypeError: (312-358): Different number of components on the left hand side (4) than on the right hand side (3).
+// TypeError: (368-407): Different number of components on the left hand side (3) than on the right hand side (4).
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/differentNumberOfComponentsFromReturn.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/differentNumberOfComponentsFromReturn.sol
new file mode 100644
index 00000000..7b556350
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/differentNumberOfComponentsFromReturn.sol
@@ -0,0 +1,29 @@
+contract C {
+    function f() public {
+        uint a = two();
+        uint b = three();
+        uint c = four();
+    }
+    function g() public {
+        (uint a1, uint b1, uint c1, uint d1) = one();
+        (uint a2, uint b2, uint c2) = one();
+        (uint a3, uint b3) = one();
+    }
+    function h() public {
+        (uint a1, uint b1, uint c1, uint d1) = three();
+        (uint a2, uint b2, uint c2) = four();
+    }
+    function one() public pure returns (uint);
+    function two() public pure returns (uint, uint);
+    function three() public pure returns (uint, uint, uint);
+    function four() public pure returns (uint, uint, uint, uint);
+}
+// ----
+// TypeError: (47-61): Different number of components on the left hand side (1) than on the right hand side (2).
+// TypeError: (71-87): Different number of components on the left hand side (1) than on the right hand side (3).
+// TypeError: (97-112): Different number of components on the left hand side (1) than on the right hand side (4).
+// TypeError: (154-198): Different number of components on the left hand side (4) than on the right hand side (1).
+// TypeError: (208-243): Different number of components on the left hand side (3) than on the right hand side (1).
+// TypeError: (253-279): Different number of components on the left hand side (2) than on the right hand side (1).
+// TypeError: (321-367): Different number of components on the left hand side (4) than on the right hand side (3).
+// TypeError: (377-413): Different number of components on the left hand side (3) than on the right hand side (4).
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/disallowWildcards.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/disallowWildcards.sol
new file mode 100644
index 00000000..b500823d
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/disallowWildcards.sol
@@ -0,0 +1,24 @@
+contract C {
+    function fn() public pure {
+        (uint a,) = (1,2,3);
+        (,uint b) = (1,2,3);
+        (,uint c,) = (1,2,3,4,5);
+        (uint d, uint e,) = (1,2,3,4);
+        (,uint f, uint g) = (1,2,3,4);
+        (,uint h, uint i,) = (1,2,3);
+        (uint j,) = 1;
+        (,uint k) = 1;
+        (,uint l,) = 1;
+        a;b;c;d;e;f;g;h;i;j;k;l;
+    }
+}
+// ----
+// TypeError: (53-72): Different number of components on the left hand side (2) than on the right hand side (3).
+// TypeError: (82-101): Different number of components on the left hand side (2) than on the right hand side (3).
+// TypeError: (111-135): Different number of components on the left hand side (3) than on the right hand side (5).
+// TypeError: (145-174): Different number of components on the left hand side (3) than on the right hand side (4).
+// TypeError: (184-213): Different number of components on the left hand side (3) than on the right hand side (4).
+// TypeError: (223-251): Different number of components on the left hand side (4) than on the right hand side (3).
+// TypeError: (261-274): Different number of components on the left hand side (2) than on the right hand side (1).
+// TypeError: (284-297): Different number of components on the left hand side (2) than on the right hand side (1).
+// TypeError: (307-321): Different number of components on the left hand side (3) than on the right hand side (1).
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/disallowWildcardsFromReturn.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/disallowWildcardsFromReturn.sol
new file mode 100644
index 00000000..3224a182
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/disallowWildcardsFromReturn.sol
@@ -0,0 +1,31 @@
+contract C {
+    function fn() public pure {
+        (uint a,) = three();
+        (,uint b) = three();
+        (,uint c,) = five();
+        (uint d, uint e,) = four();
+        (,uint f, uint g) = four();
+        (,uint h, uint i,) = three();
+        (uint j,) = one();
+        (,uint k) = one();
+        (,uint l,) = one();
+        (,uint m, uint n,) = five();
+        a;b;c;d;e;f;g;h;i;j;k;l;m;n;
+    }
+    function one() public pure returns (uint);
+    function two() public pure returns (uint, uint);
+    function three() public pure returns (uint, uint, uint);
+    function four() public pure returns (uint, uint, uint, uint);
+    function five() public pure returns (uint, uint, uint, uint, uint);
+}
+// ----
+// TypeError: (53-72): Different number of components on the left hand side (2) than on the right hand side (3).
+// TypeError: (82-101): Different number of components on the left hand side (2) than on the right hand side (3).
+// TypeError: (111-130): Different number of components on the left hand side (3) than on the right hand side (5).
+// TypeError: (140-166): Different number of components on the left hand side (3) than on the right hand side (4).
+// TypeError: (176-202): Different number of components on the left hand side (3) than on the right hand side (4).
+// TypeError: (212-240): Different number of components on the left hand side (4) than on the right hand side (3).
+// TypeError: (250-267): Different number of components on the left hand side (2) than on the right hand side (1).
+// TypeError: (277-294): Different number of components on the left hand side (2) than on the right hand side (1).
+// TypeError: (304-322): Different number of components on the left hand side (3) than on the right hand side (1).
+// TypeError: (332-359): Different number of components on the left hand side (4) than on the right hand side (5).
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationComplex.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationComplex.sol
index a3ce6a74..ba6e9916 100644
--- a/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationComplex.sol
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationComplex.sol
@@ -2,10 +2,10 @@ contract D {
   struct S { uint a; uint b; }
 }
 contract C {
-  function f() internal returns (uint, uint, uint, D.S[20] storage, uint) {
-    (,,,D.S[10*2] storage x,) = f();
+  function f() internal pure {
+    (,,,D.S[10*2] storage x,) = g();
     x;
   }
-} 
+  function g() internal pure returns (uint, uint, uint, D.S[20] storage x, uint) { x = x; }
+}
 // ----
-// Warning: (110-117): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationEmpty.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationEmpty.sol
new file mode 100644
index 00000000..9618958e
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationEmpty.sol
@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        (uint a, uint b) = f();
+        (uint c) = f();
+        uint d = f();
+    }
+}
+// ----
+// TypeError: (52-74): Different number of components on the left hand side (2) than on the right hand side (0).
+// TypeError: (84-98): Different number of components on the left hand side (1) than on the right hand side (0).
+// TypeError: (108-120): Different number of components on the left hand side (1) than on the right hand side (0).
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationSimple.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationSimple.sol
index 8e06322c..a2fcce18 100644
--- a/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationSimple.sol
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/multiVariableDeclarationSimple.sol
@@ -1,12 +1,12 @@
 contract C {
-  function f() internal returns (uint, uint, uint, uint) {
+  function f() internal pure returns (uint, uint, uint, uint) {
     (uint a, uint b,,) = f();
     a; b;
   }
-  function g() internal returns (bytes memory, string storage) {
-    (bytes memory a, string storage b) = g();
+  function g() internal pure {
+    (bytes memory a, string storage b) = h();
     a; b;
   }
-} 
+  function h() internal pure returns (bytes memory, string storage s) { s = s; }
+}
 // ----
-// Warning: (163-169): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/oneElementTuple.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/oneElementTuple.sol
new file mode 100644
index 00000000..562c7c0b
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/oneElementTuple.sol
@@ -0,0 +1,8 @@
+contract C {
+    function f() public {
+        (uint a,) = (1,);
+        a;
+    }
+}
+// ----
+// TypeError: (59-63): Tuple component cannot be empty.
diff --git a/test/libsolidity/syntaxTests/multiVariableDeclaration/sameNumberOfComponents.sol b/test/libsolidity/syntaxTests/multiVariableDeclaration/sameNumberOfComponents.sol
new file mode 100644
index 00000000..59eb34af
--- /dev/null
+++ b/test/libsolidity/syntaxTests/multiVariableDeclaration/sameNumberOfComponents.sol
@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure {
+        (uint a1, uint b1, uint c1, uint d1) = (1,2,3,4);
+        (uint a2, uint b2, uint c2) = (1,2,3);
+        (uint a3, uint b3) = (1,2);
+        a1; b1; c1; d1; a2; b2; c2; a3; b3;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/239_multi_variable_declaration_wildcards_fine.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/239_multi_variable_declaration_wildcards_fine.sol
deleted file mode 100644
index f3afd0cc..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/239_multi_variable_declaration_wildcards_fine.sol
+++ /dev/null
@@ -1,21 +0,0 @@
-contract C {
-    function three() public returns (uint, uint, uint);
-    function two() public returns (uint, uint);
-    function none() public;
-    function f() public {
-        (uint a,) = three();
-        (uint b, uint c,) = two();
-        (,uint d) = three();
-        (,uint e, uint g) = two();
-        var (,,) = three();
-        var () = none();
-        a;b;c;d;e;g;
-    }
-}
-// ----
-// SyntaxError: (307-325): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
-// SyntaxError: (335-350): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
-// Warning: (179-198): Different number of components on the left hand side (2) than on the right hand side (3).
-// Warning: (208-233): Different number of components on the left hand side (3) than on the right hand side (2).
-// Warning: (243-262): Different number of components on the left hand side (2) than on the right hand side (3).
-// Warning: (272-297): Different number of components on the left hand side (3) than on the right hand side (2).
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/240_multi_variable_declaration_wildcards_fail_1.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/240_multi_variable_declaration_wildcards_fail_1.sol
deleted file mode 100644
index 0ccbb327..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/240_multi_variable_declaration_wildcards_fail_1.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-contract C {
-    function one() public returns (uint);
-    function f() public { (uint a, uint b, ) = one(); }
-}
-// ----
-// Warning: (81-107): Different number of components on the left hand side (3) than on the right hand side (1).
-// TypeError: (81-107): Not enough components (1) in value to assign all variables (2).
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/241_multi_variable_declaration_wildcards_fail_2.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/241_multi_variable_declaration_wildcards_fail_2.sol
deleted file mode 100644
index 8d5de125..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/241_multi_variable_declaration_wildcards_fail_2.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-contract C {
-    function one() public returns (uint);
-    function f() public { (uint a, , ) = one(); }
-}
-// ----
-// Warning: (81-101): Different number of components on the left hand side (3) than on the right hand side (1).
-// TypeError: (81-101): Not enough components (1) in value to assign all variables (2).
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/242_multi_variable_declaration_wildcards_fail_3.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/242_multi_variable_declaration_wildcards_fail_3.sol
deleted file mode 100644
index 993df9b9..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/242_multi_variable_declaration_wildcards_fail_3.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-contract C {
-    function one() public returns (uint);
-    function f() public { (, , uint a) = one(); }
-}
-// ----
-// Warning: (81-101): Different number of components on the left hand side (3) than on the right hand side (1).
-// TypeError: (81-101): Not enough components (1) in value to assign all variables (2).
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/243_multi_variable_declaration_wildcards_fail_4.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/243_multi_variable_declaration_wildcards_fail_4.sol
deleted file mode 100644
index 0697b789..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/243_multi_variable_declaration_wildcards_fail_4.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-contract C {
-    function one() public returns (uint);
-    function f() public { (, uint a, uint b) = one(); }
-}
-// ----
-// Warning: (81-107): Different number of components on the left hand side (3) than on the right hand side (1).
-// TypeError: (81-107): Not enough components (1) in value to assign all variables (2).
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/244_tuples.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/244_tuples.sol
index 95e8cf37..d18c115d 100644
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/244_tuples.sol
+++ b/test/libsolidity/syntaxTests/nameAndTypeResolution/244_tuples.sol
@@ -1,13 +1,10 @@
 contract C {
-    function f() public {
+    function f() public pure {
         uint a = (1);
-        (uint b,) = uint8(1);
+        (uint b,) = (uint8(1),2);
         (uint c, uint d) = (uint32(1), 2 + a);
-        (uint e,) = (uint64(1), 2, b);
+        (uint e, ,) = (uint64(1), 2, b);
         a;b;c;d;e;
     }
 }
 // ----
-// Warning: (69-89): Different number of components on the left hand side (2) than on the right hand side (1).
-// Warning: (146-175): Different number of components on the left hand side (2) than on the right hand side (3).
-// Warning: (17-201): Function state mutability can be restricted to pure
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/246_multi_variable_declaration_wildcards_fail_5.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/246_multi_variable_declaration_wildcards_fail_5.sol
deleted file mode 100644
index 3599a342..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/246_multi_variable_declaration_wildcards_fail_5.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-contract C {
-    function one() public returns (uint);
-    function f() public { var (,) = one(); }
-}
-// ----
-// SyntaxError: (81-96): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
-// TypeError: (81-96): Wildcard both at beginning and end of variable declaration list is only allowed if the number of components is equal.
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/247_multi_variable_declaration_wildcards_fail_6.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/247_multi_variable_declaration_wildcards_fail_6.sol
deleted file mode 100644
index cc5953db..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/247_multi_variable_declaration_wildcards_fail_6.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-contract C {
-    function two() public returns (uint, uint);
-    function f() public { (uint a, uint b, uint c) = two(); }
-}
-// ----
-// Warning: (87-119): Different number of components on the left hand side (3) than on the right hand side (2).
-// TypeError: (87-119): Not enough components (2) in value to assign all variables (3).
diff --git a/test/libsolidity/syntaxTests/parsing/multi_variable_declarations.sol b/test/libsolidity/syntaxTests/parsing/multi_variable_declarations.sol
index 1984ed36..56c2e280 100644
--- a/test/libsolidity/syntaxTests/parsing/multi_variable_declarations.sol
+++ b/test/libsolidity/syntaxTests/parsing/multi_variable_declarations.sol
@@ -2,8 +2,8 @@ contract C {
 	function f() pure public {
 		(uint a, uint b, uint c) = g();
 		(uint d) = 2;
-		(, uint e) = 3;
-		(uint h,) = 4;
+		(, uint e) = (3,4);
+		(uint h,) = (4,5);
 		(uint x,,) = g();
 		(, uint y,) = g();
         a; b; c; d; e; h; x; y;
@@ -11,5 +11,3 @@ contract C {
 	function g() pure public returns (uint, uint, uint) {}
 }
 // ----
-// Warning: (93-107): Different number of components on the left hand side (2) than on the right hand side (1).
-// Warning: (111-124): Different number of components on the left hand side (2) than on the right hand side (1).
diff --git a/test/libsolidity/syntaxTests/parsing/tuples.sol b/test/libsolidity/syntaxTests/parsing/tuples.sol
index ca2f9d6b..875556e9 100644
--- a/test/libsolidity/syntaxTests/parsing/tuples.sol
+++ b/test/libsolidity/syntaxTests/parsing/tuples.sol
@@ -1,16 +1,11 @@
 contract C {
-	function f() public {
+	function f() public pure {
 		uint a = (1);
-		(uint b,) = 1;
+		(uint b,) = (1,2);
 		(uint c, uint d) = (1, 2 + a);
-		(uint e,) = (1, 2, b);
+		(uint e,) = (1, b);
 		(a) = 3;
+		a;b;c;d;e;
 	}
 }
 // ----
-// Warning: (54-67): Different number of components on the left hand side (2) than on the right hand side (1).
-// Warning: (104-125): Different number of components on the left hand side (2) than on the right hand side (3).
-// Warning: (72-78): Unused local variable.
-// Warning: (80-86): Unused local variable.
-// Warning: (105-111): Unused local variable.
-// Warning: (14-140): Function state mutability can be restricted to pure
diff --git a/test/libsolidity/syntaxTests/tupleAssignments/warn_fill_vardecl.sol b/test/libsolidity/syntaxTests/tupleAssignments/warn_fill_vardecl.sol
deleted file mode 100644
index 23484567..00000000
--- a/test/libsolidity/syntaxTests/tupleAssignments/warn_fill_vardecl.sol
+++ /dev/null
@@ -1,8 +0,0 @@
-contract C {
-	function f() public pure returns (uint, uint, uint, uint) {
-		(uint a, uint b,) = f();
-		a; b;
-	}
-}
-// ----
-// Warning: (76-99): Different number of components on the left hand side (3) than on the right hand side (4).
diff --git a/test/libsolidity/syntaxTests/types/unnamed_tuple_decl.sol b/test/libsolidity/syntaxTests/types/unnamed_tuple_decl.sol
index 6c1489f5..7ed92b58 100644
--- a/test/libsolidity/syntaxTests/types/unnamed_tuple_decl.sol
+++ b/test/libsolidity/syntaxTests/types/unnamed_tuple_decl.sol
@@ -16,4 +16,3 @@ contract C {
 // SyntaxError: (249-261): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
 // SyntaxError: (271-283): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
 // SyntaxError: (293-306): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
-// TypeError: (271-283): Too many components (1) in value for variable assignment (0) needed