diff --git a/libjulia/backends/evm/AbstractAssembly.h b/libjulia/backends/evm/AbstractAssembly.h index f667c1a76..cfc9b8a55 100644 --- a/libjulia/backends/evm/AbstractAssembly.h +++ b/libjulia/backends/evm/AbstractAssembly.h @@ -89,6 +89,9 @@ public: /// Return from a subroutine. /// @param _stackDiffAfter the stack adjustment after this instruction. virtual void appendReturnsub(int _returns, int _stackDiffAfter = 0) = 0; + + /// Append the assembled size as a constant. + virtual void appendAssemblySize() = 0; }; enum class IdentifierContext { LValue, RValue }; diff --git a/libjulia/backends/evm/EVMAssembly.cpp b/libjulia/backends/evm/EVMAssembly.cpp index 7ec26957c..173d5e934 100644 --- a/libjulia/backends/evm/EVMAssembly.cpp +++ b/libjulia/backends/evm/EVMAssembly.cpp @@ -32,6 +32,8 @@ namespace { /// Size of labels in bytes. Four-byte labels are required by some EVM1.5 instructions. size_t constexpr labelReferenceSize = 4; + +size_t constexpr assemblySizeReferenceSize = 4; } @@ -145,17 +147,19 @@ void EVMAssembly::appendReturnsub(int _returns, int _stackDiffAfter) eth::LinkerObject EVMAssembly::finalize() { + size_t bytecodeSize = m_bytecode.size(); + for (auto const& ref: m_assemblySizePositions) + updateReference(ref, assemblySizeReferenceSize, u256(bytecodeSize)); + for (auto const& ref: m_labelReferences) { size_t referencePos = ref.first; solAssert(m_labelPositions.count(ref.second), ""); size_t labelPos = m_labelPositions.at(ref.second); solAssert(labelPos != size_t(-1), "Undefined but allocated label used."); - solAssert(m_bytecode.size() >= 4 && referencePos <= m_bytecode.size() - 4, ""); - solAssert(uint64_t(labelPos) < (uint64_t(1) << (8 * labelReferenceSize)), ""); - for (size_t i = 0; i < labelReferenceSize; i++) - m_bytecode[referencePos + i] = byte((labelPos >> (8 * (labelReferenceSize - i - 1))) & 0xff); + updateReference(referencePos, labelReferenceSize, u256(labelPos)); } + eth::LinkerObject obj; obj.bytecode = m_bytecode; return obj; @@ -173,3 +177,18 @@ void EVMAssembly::appendLabelReferenceInternal(LabelID _labelId) m_labelReferences[m_bytecode.size()] = _labelId; m_bytecode += bytes(labelReferenceSize); } + +void EVMAssembly::appendAssemblySize() +{ + appendInstruction(solidity::pushInstruction(assemblySizeReferenceSize)); + m_assemblySizePositions.push_back(m_bytecode.size()); + m_bytecode += bytes(assemblySizeReferenceSize); +} + +void EVMAssembly::updateReference(size_t pos, size_t size, u256 value) +{ + solAssert(m_bytecode.size() >= size && pos <= m_bytecode.size() - size, ""); + solAssert(value < (u256(1) << (8 * size)), ""); + for (size_t i = 0; i < size; i++) + m_bytecode[pos + i] = byte((value >> (8 * (size - i - 1))) & 0xff); +} diff --git a/libjulia/backends/evm/EVMAssembly.h b/libjulia/backends/evm/EVMAssembly.h index a2df0cdc2..695858226 100644 --- a/libjulia/backends/evm/EVMAssembly.h +++ b/libjulia/backends/evm/EVMAssembly.h @@ -70,6 +70,8 @@ public: /// Return from a subroutine. virtual void appendReturnsub(int _returns, int _stackDiffAfter) override; + /// Append the assembled size as a constant. + virtual void appendAssemblySize() override; /// Resolves references inside the bytecode and returns the linker object. eth::LinkerObject finalize(); @@ -77,6 +79,7 @@ public: private: void setLabelToCurrentPosition(AbstractAssembly::LabelID _labelId); void appendLabelReferenceInternal(AbstractAssembly::LabelID _labelId); + void updateReference(size_t pos, size_t size, u256 value); bool m_evm15 = false; ///< if true, switch to evm1.5 mode LabelID m_nextLabelId = 0; @@ -84,6 +87,7 @@ private: bytes m_bytecode; std::map m_labelPositions; std::map m_labelReferences; + std::vector m_assemblySizePositions; }; } diff --git a/libsolidity/inlineasm/AsmCodeGen.cpp b/libsolidity/inlineasm/AsmCodeGen.cpp index 3c7c62c6a..2bbd1b70a 100644 --- a/libsolidity/inlineasm/AsmCodeGen.cpp +++ b/libsolidity/inlineasm/AsmCodeGen.cpp @@ -121,6 +121,11 @@ public: solAssert(false, "RETURNSUB not implemented for EVM 1.0"); } + virtual void appendAssemblySize() override + { + m_assembly.appendProgramSize(); + } + private: LabelID assemblyTagToIdentifier(eth::AssemblyItem const& _tag) const {