Merge pull request #6445 from ethereum/circularStorageMemoryCopy

Implemented copying recursive structs from storage to memory.

Changelog.md

@@ -1,6 +1,7 @@
 ### 0.5.8 (unreleased)
 
 Language Features:
+ * Code Generation: Implement copying recursive structs from storage to memory.
 
 
 Compiler Features:

libsolidity/codegen/CompilerUtils.cpp

@@ -987,25 +987,42 @@ void CompilerUtils::convertType(
 			switch (typeOnStack.location())
 			{
 			case DataLocation::Storage:
+			{
+				auto conversionImpl = [
+					typeOnStack = dynamic_pointer_cast<StructType const>(_typeOnStack.shared_from_this()),
+					targetType = dynamic_pointer_cast<StructType const>(targetType.shared_from_this())
+				](CompilerContext& _context) {
+					CompilerUtils utils(_context);
 					// stack: <source ref>
-				allocateMemory(typeOnStack.memorySize());
-				m_context << Instruction::SWAP1 << Instruction::DUP2;
+					utils.allocateMemory(typeOnStack->memorySize());
+					_context << Instruction::SWAP1 << Instruction::DUP2;
 					// stack: <memory ptr> <source ref> <memory ptr>
-				for (auto const& member: typeOnStack.members(nullptr))
+					for (auto const& member: typeOnStack->members(nullptr))
 					{
 						if (!member.type->canLiveOutsideStorage())
 							continue;
-					pair<u256, unsigned> const& offsets = typeOnStack.storageOffsetsOfMember(member.name);
-					m_context << offsets.first << Instruction::DUP3 << Instruction::ADD;
-					m_context << u256(offsets.second);
-					StorageItem(m_context, *member.type).retrieveValue(SourceLocation(), true);
-					TypePointer targetMemberType = targetType.memberType(member.name);
+						pair<u256, unsigned> const& offsets = typeOnStack->storageOffsetsOfMember(member.name);
+						_context << offsets.first << Instruction::DUP3 << Instruction::ADD;
+						_context << u256(offsets.second);
+						StorageItem(_context, *member.type).retrieveValue(SourceLocation(), true);
+						TypePointer targetMemberType = targetType->memberType(member.name);
 						solAssert(!!targetMemberType, "Member not found in target type.");
-					convertType(*member.type, *targetMemberType, true);
-					storeInMemoryDynamic(*targetMemberType, true);
+						utils.convertType(*member.type, *targetMemberType, true);
+						utils.storeInMemoryDynamic(*targetMemberType, true);
 					}
-				m_context << Instruction::POP << Instruction::POP;
+					_context << Instruction::POP << Instruction::POP;
+				};
+				if (typeOnStack.recursive())
+					m_context.callLowLevelFunction(
+						"$convertRecursiveArrayStorageToMemory_" + typeOnStack.identifier() + "_to_" + targetType.identifier(),
+						1,
+						1,
+						conversionImpl
+					);
+				else
+					conversionImpl(m_context);
 				break;
+			}
 			case DataLocation::CallData:
 			{
 				solUnimplementedAssert(!typeOnStack.isDynamicallyEncoded(), "");

test/libsolidity/semanticTests/structs/conversion/recursive_storage_memory.sol

@@ -0,0 +1,20 @@
+contract CopyTest {
+	struct Tree {
+		Tree[] children;
+	}
+	Tree storageTree;
+
+	constructor() public {
+		storageTree.children.length = 2;
+		storageTree.children[0].children.length = 23;
+		storageTree.children[1].children.length = 42;
+	}
+
+	function run() public returns (uint256, uint256, uint256) {
+		Tree memory memoryTree;
+		memoryTree = storageTree;
+		return (memoryTree.children.length, memoryTree.children[0].children.length, memoryTree.children[1].children.length);
+	}
+}
+// ----
+// run() -> 2, 23, 42

test/libsolidity/semanticTests/structs/conversion/recursive_storage_memory_complex.sol

@@ -0,0 +1,46 @@
+contract CopyTest {
+	struct Tree {
+		uint256 data;
+		Tree[] children;
+	}
+	Tree storageTree;
+
+	constructor() public {
+		storageTree.data = 0x42;
+		storageTree.children.length = 2;
+		storageTree.children[0].data = 0x4200;
+		storageTree.children[1].data = 0x4201;
+		storageTree.children[0].children.length = 3;
+		for (uint i = 0; i < 3; i++)
+		    storageTree.children[0].children[i].data = 0x420000 + i;
+		storageTree.children[1].children.length = 4;
+		for (uint i = 0; i < 4; i++)
+		    storageTree.children[1].children[i].data = 0x420100 + i;
+	}
+
+	function countData(Tree memory tree) internal returns (uint256 c) {
+	    c = 1;
+	    for (uint i = 0; i < tree.children.length; i++) {
+	        c += countData(tree.children[i]);
+	    }
+	}
+
+	function copyFromTree(Tree memory tree, uint256[] memory data, uint256 offset) internal returns (uint256) {
+	    data[offset++] = tree.data;
+	    for (uint i = 0; i < tree.children.length; i++) {
+	        offset = copyFromTree(tree.children[i], data, offset);
+	    }
+	    return offset;
+	}
+
+	function run() public returns (uint256[] memory) {
+		Tree memory memoryTree;
+		memoryTree = storageTree;
+		uint256 length = countData(memoryTree);
+		uint256[] memory result = new uint256[](length);
+		copyFromTree(memoryTree, result, 0);
+		return result;
+	}
+}
+// ----
+// run() -> 0x20, 10, 0x42, 0x4200, 0x420000, 0x420001, 0x420002, 0x4201, 0x420100, 0x420101, 0x420102, 0x420103