diff options
Diffstat (limited to 'libsolidity/codegen')
| -rw-r--r-- | libsolidity/codegen/ArrayUtils.cpp | 49 | ||||
| -rw-r--r-- | libsolidity/codegen/ArrayUtils.h | 6 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.cpp | 66 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.h | 7 | ||||
| -rw-r--r-- | libsolidity/codegen/ContractCompiler.cpp | 10 | ||||
| -rw-r--r-- | libsolidity/codegen/ExpressionCompiler.cpp | 50 |
6 files changed, 138 insertions, 50 deletions
diff --git a/libsolidity/codegen/ArrayUtils.cpp b/libsolidity/codegen/ArrayUtils.cpp index 4703fc1f..0fe66d2d 100644 --- a/libsolidity/codegen/ArrayUtils.cpp +++ b/libsolidity/codegen/ArrayUtils.cpp @@ -774,6 +774,55 @@ void ArrayUtils::resizeDynamicArray(ArrayType const& _typeIn) const ); } +void ArrayUtils::incrementDynamicArraySize(ArrayType const& _type) const +{ + solAssert(_type.location() == DataLocation::Storage, ""); + solAssert(_type.isDynamicallySized(), ""); + if (!_type.isByteArray() && _type.baseType()->storageBytes() < 32) + solAssert(_type.baseType()->isValueType(), "Invalid storage size for non-value type."); + + if (_type.isByteArray()) + { + // We almost always just add 2 (length of byte arrays is shifted left by one) + // except for the case where we transition from a short byte array + // to a long byte array, there we have to copy. + // This happens if the length is exactly 31, which means that the + // lowest-order byte (we actually use a mask with fewer bits) must + // be (31*2+0) = 62 + + m_context.appendInlineAssembly(R"({ + let data := sload(ref) + let shifted_length := and(data, 63) + // We have to copy if length is exactly 31, because that marks + // the transition between in-place and out-of-place storage. + switch shifted_length + case 62 + { + mstore(0, ref) + let data_area := keccak256(0, 0x20) + sstore(data_area, and(data, not(0xff))) + // New length is 32, encoded as (32 * 2 + 1) + sstore(ref, 65) + // Replace ref variable by new length + ref := 32 + } + default + { + sstore(ref, add(data, 2)) + // Replace ref variable by new length + if iszero(and(data, 1)) { data := shifted_length } + ref := add(div(data, 2), 1) + } + })", {"ref"}); + } + else + m_context.appendInlineAssembly(R"({ + let new_length := add(sload(ref), 1) + sstore(ref, new_length) + ref := new_length + })", {"ref"}); +} + void ArrayUtils::clearStorageLoop(TypePointer const& _type) const { m_context.callLowLevelFunction( diff --git a/libsolidity/codegen/ArrayUtils.h b/libsolidity/codegen/ArrayUtils.h index f3ddc4ee..99786397 100644 --- a/libsolidity/codegen/ArrayUtils.h +++ b/libsolidity/codegen/ArrayUtils.h @@ -67,6 +67,12 @@ public: /// Stack pre: reference (excludes byte offset) new_length /// Stack post: void resizeDynamicArray(ArrayType const& _type) const; + /// Increments the size of a dynamic array by one. + /// Does not touch the new data element. In case of a byte array, this might move the + /// data. + /// Stack pre: reference (excludes byte offset) + /// Stack post: new_length + void incrementDynamicArraySize(ArrayType const& _type) const; /// Appends a loop that clears a sequence of storage slots of the given type (excluding end). /// Stack pre: end_ref start_ref /// Stack post: end_ref diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 676d5d4e..79aef7b0 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -21,6 +21,7 @@ */ #include <libsolidity/codegen/CompilerUtils.h> + #include <libsolidity/ast/AST.h> #include <libsolidity/codegen/ArrayUtils.h> #include <libsolidity/codegen/LValue.h> @@ -39,11 +40,17 @@ namespace solidity const unsigned CompilerUtils::dataStartOffset = 4; const size_t CompilerUtils::freeMemoryPointer = 64; +const size_t CompilerUtils::zeroPointer = CompilerUtils::freeMemoryPointer + 32; +const size_t CompilerUtils::generalPurposeMemoryStart = CompilerUtils::zeroPointer + 32; const unsigned CompilerUtils::identityContractAddress = 4; +static_assert(CompilerUtils::freeMemoryPointer >= 64, "Free memory pointer must not overlap with scratch area."); +static_assert(CompilerUtils::zeroPointer >= CompilerUtils::freeMemoryPointer + 32, "Zero pointer must not overlap with free memory pointer."); +static_assert(CompilerUtils::generalPurposeMemoryStart >= CompilerUtils::zeroPointer + 32, "General purpose memory must not overlap with zero area."); + void CompilerUtils::initialiseFreeMemoryPointer() { - m_context << u256(freeMemoryPointer + 32); + m_context << u256(generalPurposeMemoryStart); storeFreeMemoryPointer(); } @@ -495,14 +502,34 @@ void CompilerUtils::abiDecodeV2(TypePointers const& _parameterTypes, bool _fromM void CompilerUtils::zeroInitialiseMemoryArray(ArrayType const& _type) { - auto repeat = m_context.newTag(); - m_context << repeat; - pushZeroValue(*_type.baseType()); - storeInMemoryDynamic(*_type.baseType()); - m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1; - m_context << Instruction::SUB << Instruction::SWAP1; - m_context << Instruction::DUP2; - m_context.appendConditionalJumpTo(repeat); + if (_type.baseType()->hasSimpleZeroValueInMemory()) + { + solAssert(_type.baseType()->isValueType(), ""); + Whiskers templ(R"({ + let size := mul(length, <element_size>) + // cheap way of zero-initializing a memory range + codecopy(memptr, codesize(), size) + memptr := add(memptr, size) + })"); + templ("element_size", to_string(_type.baseType()->memoryHeadSize())); + m_context.appendInlineAssembly(templ.render(), {"length", "memptr"}); + } + else + { + // TODO: Potential optimization: + // When we create a new multi-dimensional dynamic array, each element + // is initialized to an empty array. It actually does not hurt + // to re-use exactly the same empty array for all elements. Currently, + // a new one is created each time. + auto repeat = m_context.newTag(); + m_context << repeat; + pushZeroValue(*_type.baseType()); + storeInMemoryDynamic(*_type.baseType()); + m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1; + m_context << Instruction::SUB << Instruction::SWAP1; + m_context << Instruction::DUP2; + m_context.appendConditionalJumpTo(repeat); + } m_context << Instruction::SWAP1 << Instruction::POP; } @@ -1031,6 +1058,13 @@ void CompilerUtils::pushZeroValue(Type const& _type) return; } solAssert(referenceType->location() == DataLocation::Memory, ""); + if (auto arrayType = dynamic_cast<ArrayType const*>(&_type)) + if (arrayType->isDynamicallySized()) + { + // Push a memory location that is (hopefully) always zero. + pushZeroPointer(); + return; + } TypePointer type = _type.shared_from_this(); m_context.callLowLevelFunction( @@ -1051,13 +1085,8 @@ void CompilerUtils::pushZeroValue(Type const& _type) } else if (auto arrayType = dynamic_cast<ArrayType const*>(type.get())) { - if (arrayType->isDynamicallySized()) - { - // zero length - _context << u256(0); - utils.storeInMemoryDynamic(IntegerType(256)); - } - else if (arrayType->length() > 0) + solAssert(!arrayType->isDynamicallySized(), ""); + if (arrayType->length() > 0) { _context << arrayType->length() << Instruction::SWAP1; // stack: items_to_do memory_pos @@ -1074,6 +1103,11 @@ void CompilerUtils::pushZeroValue(Type const& _type) ); } +void CompilerUtils::pushZeroPointer() +{ + m_context << u256(zeroPointer); +} + void CompilerUtils::moveToStackVariable(VariableDeclaration const& _variable) { unsigned const stackPosition = m_context.baseToCurrentStackOffset(m_context.baseStackOffsetOfVariable(_variable)); diff --git a/libsolidity/codegen/CompilerUtils.h b/libsolidity/codegen/CompilerUtils.h index 389673ef..a32c5c6e 100644 --- a/libsolidity/codegen/CompilerUtils.h +++ b/libsolidity/codegen/CompilerUtils.h @@ -210,6 +210,9 @@ public: /// Creates a zero-value for the given type and puts it onto the stack. This might allocate /// memory for memory references. void pushZeroValue(Type const& _type); + /// Pushes a pointer to the stack that points to a (potentially shared) location in memory + /// that always contains a zero. It is not allowed to write there. + void pushZeroPointer(); /// Moves the value that is at the top of the stack to a stack variable. void moveToStackVariable(VariableDeclaration const& _variable); @@ -255,6 +258,10 @@ public: /// Position of the free-memory-pointer in memory; static const size_t freeMemoryPointer; + /// Position of the memory slot that is always zero. + static const size_t zeroPointer; + /// Starting offset for memory available to the user (aka the contract). + static const size_t generalPurposeMemoryStart; private: /// Address of the precompiled identity contract. diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp index 791edc65..d3a7e4ea 100644 --- a/libsolidity/codegen/ContractCompiler.cpp +++ b/libsolidity/codegen/ContractCompiler.cpp @@ -143,8 +143,9 @@ void ContractCompiler::appendInitAndConstructorCode(ContractDefinition const& _c for (auto const& modifier: constructor->modifiers()) { auto baseContract = dynamic_cast<ContractDefinition const*>( - modifier->name()->annotation().referencedDeclaration); - if (baseContract) + modifier->name()->annotation().referencedDeclaration + ); + if (baseContract && !modifier->arguments().empty()) if (m_baseArguments.count(baseContract->constructor()) == 0) m_baseArguments[baseContract->constructor()] = &modifier->arguments(); } @@ -156,8 +157,8 @@ void ContractCompiler::appendInitAndConstructorCode(ContractDefinition const& _c ); solAssert(baseContract, ""); - if (m_baseArguments.count(baseContract->constructor()) == 0) - m_baseArguments[baseContract->constructor()] = &base->arguments(); + if (!m_baseArguments.count(baseContract->constructor()) && base->arguments() && !base->arguments()->empty()) + m_baseArguments[baseContract->constructor()] = base->arguments(); } } // Initialization of state variables in base-to-derived order. @@ -238,6 +239,7 @@ void ContractCompiler::appendBaseConstructor(FunctionDefinition const& _construc solAssert(m_baseArguments.count(&_constructor), ""); std::vector<ASTPointer<Expression>> const* arguments = m_baseArguments[&_constructor]; solAssert(arguments, ""); + solAssert(arguments->size() == constructorType.parameterTypes().size(), ""); for (unsigned i = 0; i < arguments->size(); ++i) compileExpression(*(arguments->at(i)), constructorType.parameterTypes()[i]); } diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp index 9e2d30d5..57d49ac6 100644 --- a/libsolidity/codegen/ExpressionCompiler.cpp +++ b/libsolidity/codegen/ExpressionCompiler.cpp @@ -821,24 +821,27 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) function.kind() == FunctionType::Kind::ArrayPush ? make_shared<ArrayType>(DataLocation::Storage, paramType) : make_shared<ArrayType>(DataLocation::Storage); - // get the current length - ArrayUtils(m_context).retrieveLength(*arrayType); - m_context << Instruction::DUP1; - // stack: ArrayReference currentLength currentLength - m_context << u256(1) << Instruction::ADD; - // stack: ArrayReference currentLength newLength - m_context << Instruction::DUP3 << Instruction::DUP2; - ArrayUtils(m_context).resizeDynamicArray(*arrayType); - m_context << Instruction::SWAP2 << Instruction::SWAP1; - // stack: newLength ArrayReference oldLength - ArrayUtils(m_context).accessIndex(*arrayType, false); - // stack: newLength storageSlot slotOffset + // stack: ArrayReference arguments[0]->accept(*this); + TypePointer const& argType = arguments[0]->annotation().type; + // stack: ArrayReference argValue + utils().moveToStackTop(argType->sizeOnStack(), 1); + // stack: argValue ArrayReference + m_context << Instruction::DUP1; + ArrayUtils(m_context).incrementDynamicArraySize(*arrayType); + // stack: argValue ArrayReference newLength + m_context << Instruction::SWAP1; + // stack: argValue newLength ArrayReference + m_context << u256(1) << Instruction::DUP3 << Instruction::SUB; + // stack: argValue newLength ArrayReference (newLength-1) + ArrayUtils(m_context).accessIndex(*arrayType, false); + // stack: argValue newLength storageSlot slotOffset + utils().moveToStackTop(3, argType->sizeOnStack()); // stack: newLength storageSlot slotOffset argValue TypePointer type = arguments[0]->annotation().type->closestTemporaryType(arrayType->baseType()); solAssert(type, ""); - utils().convertType(*arguments[0]->annotation().type, *type); + utils().convertType(*argType, *type); utils().moveToStackTop(1 + type->sizeOnStack()); utils().moveToStackTop(1 + type->sizeOnStack()); // stack: newLength argValue storageSlot slotOffset @@ -850,8 +853,6 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) } case FunctionType::Kind::ObjectCreation: { - // Will allocate at the end of memory (MSIZE) and not write at all unless the base - // type is dynamically sized. ArrayType const& arrayType = dynamic_cast<ArrayType const&>(*_functionCall.annotation().type); _functionCall.expression().accept(*this); solAssert(arguments.size() == 1, ""); @@ -861,15 +862,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) utils().convertType(*arguments[0]->annotation().type, IntegerType(256)); // Stack: requested_length - // Allocate at max(MSIZE, freeMemoryPointer) utils().fetchFreeMemoryPointer(); - m_context << Instruction::DUP1 << Instruction::MSIZE; - m_context << Instruction::LT; - auto initialise = m_context.appendConditionalJump(); - // Free memory pointer does not point to empty memory, use MSIZE. - m_context << Instruction::POP; - m_context << Instruction::MSIZE; - m_context << initialise; // Stack: requested_length memptr m_context << Instruction::SWAP1; @@ -894,13 +887,10 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) // Check if length is zero m_context << Instruction::DUP1 << Instruction::ISZERO; auto skipInit = m_context.appendConditionalJump(); - - // We only have to initialise if the base type is a not a value type. - if (dynamic_cast<ReferenceType const*>(arrayType.baseType().get())) - { - m_context << Instruction::DUP2 << u256(32) << Instruction::ADD; - utils().zeroInitialiseMemoryArray(arrayType); - } + // Always initialize because the free memory pointer might point at + // a dirty memory area. + m_context << Instruction::DUP2 << u256(32) << Instruction::ADD; + utils().zeroInitialiseMemoryArray(arrayType); m_context << skipInit; m_context << Instruction::POP; break; |