Merge pull request #4736 from ethereum/removeFillRight

Remove remaining instances of ``fillRight``.

Changelog.md

@@ -90,6 +90,7 @@ Bugfixes:
  * Type Checker: Disallow assignments to mappings within tuple assignments as well.
  * Type Checker: Allow assignments to local variables of mapping types.
  * Type Checker: Consider fixed size arrays when checking for recursive structs.
+ * Type Checker: Fix crashes in erroneous tuple assignments in which the type of the right hand side cannot be determined.
  * Type Checker: Report error when using structs in events without experimental ABIEncoderV2. This used to crash or log the wrong values.
  * Type System: Allow arbitrary exponents for literals with a mantissa of zero.
 

libsolidity/analysis/TypeChecker.cpp

@@ -498,7 +498,12 @@ void TypeChecker::checkDoubleStorageAssignment(Assignment const& _assignment)
 	TupleType const& lhs = dynamic_cast<TupleType const&>(*type(_assignment.leftHandSide()));
 	TupleType const& rhs = dynamic_cast<TupleType const&>(*type(_assignment.rightHandSide()));
 
-	bool fillRight = !lhs.components().empty() && (!lhs.components().back() || lhs.components().front());
+	if (lhs.components().size() != rhs.components().size())
+	{
+		solAssert(m_errorReporter.hasErrors(), "");
+		return;
+	}
+
 	size_t storageToStorageCopies = 0;
 	size_t toStorageCopies = 0;
 	for (size_t i = 0; i < lhs.components().size(); ++i)
@@ -506,10 +511,8 @@ void TypeChecker::checkDoubleStorageAssignment(Assignment const& _assignment)
 		ReferenceType const* ref = dynamic_cast<ReferenceType const*>(lhs.components()[i].get());
 		if (!ref || !ref->dataStoredIn(DataLocation::Storage) || ref->isPointer())
 			continue;
-		size_t rhsPos = fillRight ? i : rhs.components().size() - (lhs.components().size() - i);
-		solAssert(rhsPos < rhs.components().size(), "");
 		toStorageCopies++;
-		if (rhs.components()[rhsPos]->dataStoredIn(DataLocation::Storage))
+		if (rhs.components()[i]->dataStoredIn(DataLocation::Storage))
 			storageToStorageCopies++;
 	}
 	if (storageToStorageCopies >= 1 && toStorageCopies >= 2)

libsolidity/ast/Types.cpp

@@ -2293,16 +2293,14 @@ TypePointer TupleType::closestTemporaryType(TypePointer const& _targetType) cons
 {
 	solAssert(!!_targetType, "");
 	TypePointers const& targetComponents = dynamic_cast<TupleType const&>(*_targetType).components();
-	bool fillRight = !targetComponents.empty() && (!targetComponents.back() || targetComponents.front());
+	solAssert(components().size() == targetComponents.size(), "");
 	TypePointers tempComponents(targetComponents.size());
-	for (size_t i = 0; i < min(targetComponents.size(), components().size()); ++i)
+	for (size_t i = 0; i < targetComponents.size(); ++i)
 	{
-		size_t si = fillRight ? i : components().size() - i - 1;
-		size_t ti = fillRight ? i : targetComponents.size() - i - 1;
-		if (components()[si] && targetComponents[ti])
+		if (components()[i] && targetComponents[i])
 		{
-			tempComponents[ti] = components()[si]->closestTemporaryType(targetComponents[ti]);
-			solAssert(tempComponents[ti], "");
+			tempComponents[i] = components()[i]->closestTemporaryType(targetComponents[i]);
+			solAssert(tempComponents[i], "");
 		}
 	}
 	return make_shared<TupleType>(tempComponents);

libsolidity/codegen/CompilerUtils.cpp

@@ -947,20 +947,12 @@ void CompilerUtils::convertType(
 	{
 		TupleType const& sourceTuple = dynamic_cast<TupleType const&>(_typeOnStack);
 		TupleType const& targetTuple = dynamic_cast<TupleType const&>(_targetType);
-		// fillRight: remove excess values at right side, !fillRight: remove eccess values at left side
-		bool fillRight = !targetTuple.components().empty() && (
-			!targetTuple.components().back() ||
-			targetTuple.components().front()
-		);
+		solAssert(targetTuple.components().size() == sourceTuple.components().size(), "");
 		unsigned depth = sourceTuple.sizeOnStack();
 		for (size_t i = 0; i < sourceTuple.components().size(); ++i)
 		{
 			TypePointer sourceType = sourceTuple.components()[i];
-			TypePointer targetType;
-			if (fillRight && i < targetTuple.components().size())
-				targetType = targetTuple.components()[i];
-			else if (!fillRight && targetTuple.components().size() + i >= sourceTuple.components().size())
-				targetType = targetTuple.components()[targetTuple.components().size() - (sourceTuple.components().size() - i)];
+			TypePointer targetType = targetTuple.components()[i];
 			if (!sourceType)
 			{
 				solAssert(!targetType, "");

test/libsolidity/syntaxTests/tupleAssignments/double_storage_crash.sol

@@ -0,0 +1,11 @@
+// This used to crash in certain compiler versions.
+contract CrashContract {
+       struct S { uint a; }
+       S x;
+       function f() public {
+               (x, x) = 1(x, x);
+       }
+}
+// ----
+// TypeError: (170-177): Type is not callable
+// TypeError: (170-177): Type tuple() is not implicitly convertible to expected type tuple(struct CrashContract.S storage ref,struct CrashContract.S storage ref).

test/libsolidity/syntaxTests/tupleAssignments/err_multiple_storage_storage_copies_fill_left.sol

@@ -1,10 +0,0 @@
-contract C {
-	struct S { uint a; uint b; }
-	S x; S y;
-	function f() public {
-		(,x, y) = (1, 2, y, x);
-	}
-}
-// ----
-// TypeError: (89-101): Type tuple(int_const 1,int_const 2,struct C.S storage ref,struct C.S storage ref) is not implicitly convertible to expected type tuple(,struct C.S storage ref,struct C.S storage ref).
-// Warning: (79-101): This assignment performs two copies to storage. Since storage copies do not first copy to a temporary location, one of them might be overwritten before the second is executed and thus may have unexpected effects. It is safer to perform the copies separately or assign to storage pointers first.

test/libsolidity/syntaxTests/tupleAssignments/err_multiple_storage_storage_copies_fill_right.sol

@@ -1,10 +0,0 @@
-contract C {
-	struct S { uint a; uint b; }
-	S x; S y;
-	function f() public {
-		(x, y, ) = (y, x, 1, 2);
-	}
-}
-// ----
-// TypeError: (90-102): Type tuple(struct C.S storage ref,struct C.S storage ref,int_const 1,int_const 2) is not implicitly convertible to expected type tuple(struct C.S storage ref,struct C.S storage ref,).
-// Warning: (79-102): This assignment performs two copies to storage. Since storage copies do not first copy to a temporary location, one of them might be overwritten before the second is executed and thus may have unexpected effects. It is safer to perform the copies separately or assign to storage pointers first.