/* This file is part of solidity. solidity is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. solidity is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with solidity. If not, see . */ // SPDX-License-Identifier: GPL-3.0 /** * @author Christian * @date 2014 * Utilities for the solidity compiler. */ #pragma once #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include namespace solidity::frontend { class Compiler; /** * Context to be shared by all units that compile the same contract. * It stores the generated bytecode and the position of identifiers in memory and on the stack. */ class CompilerContext { public: explicit CompilerContext( langutil::EVMVersion _evmVersion, RevertStrings _revertStrings, CompilerContext* _runtimeContext = nullptr ): m_asm(std::make_shared()), m_evmVersion(_evmVersion), m_revertStrings(_revertStrings), m_reservedMemory{0}, m_runtimeContext(_runtimeContext), m_abiFunctions(m_evmVersion, m_revertStrings, m_yulFunctionCollector), m_yulUtilFunctions(m_evmVersion, m_revertStrings, m_yulFunctionCollector) { if (m_runtimeContext) m_runtimeSub = size_t(m_asm->newSub(m_runtimeContext->m_asm).data()); } langutil::EVMVersion const& evmVersion() const { return m_evmVersion; } void setUseABICoderV2(bool _value) { m_useABICoderV2 = _value; } bool useABICoderV2() const { return m_useABICoderV2; } void addStateVariable(VariableDeclaration const& _declaration, u256 const& _storageOffset, unsigned _byteOffset); void addImmutable(VariableDeclaration const& _declaration); /// @returns the reserved memory for storing the value of the immutable @a _variable during contract creation. size_t immutableMemoryOffset(VariableDeclaration const& _variable) const; /// @returns a list of slot names referring to the stack slots of an immutable variable. static std::vector immutableVariableSlotNames(VariableDeclaration const& _variable); /// @returns the reserved memory and resets it to mark it as used. size_t reservedMemory(); void addVariable(VariableDeclaration const& _declaration, unsigned _offsetToCurrent = 0); void removeVariable(Declaration const& _declaration); /// Removes all local variables currently allocated above _stackHeight. void removeVariablesAboveStackHeight(unsigned _stackHeight); /// Returns the number of currently allocated local variables. unsigned numberOfLocalVariables() const; void setOtherCompilers(std::map> const& _otherCompilers) { m_otherCompilers = _otherCompilers; } std::shared_ptr compiledContract(ContractDefinition const& _contract) const; std::shared_ptr compiledContractRuntime(ContractDefinition const& _contract) const; void setStackOffset(int _offset) { m_asm->setDeposit(_offset); } void adjustStackOffset(int _adjustment) { m_asm->adjustDeposit(_adjustment); } unsigned stackHeight() const { solAssert(m_asm->deposit() >= 0, ""); return unsigned(m_asm->deposit()); } bool isLocalVariable(Declaration const* _declaration) const; bool isStateVariable(Declaration const* _declaration) const { return m_stateVariables.count(_declaration) != 0; } /// @returns the entry label of the given function and creates it if it does not exist yet. evmasm::AssemblyItem functionEntryLabel(Declaration const& _declaration); /// @returns the entry label of the given function. Might return an AssemblyItem of type /// UndefinedItem if it does not exist yet. evmasm::AssemblyItem functionEntryLabelIfExists(Declaration const& _declaration) const; /// @returns the function that overrides the given declaration from the most derived class just /// above _base in the current inheritance hierarchy. FunctionDefinition const& superFunction(FunctionDefinition const& _function, ContractDefinition const& _base); /// Sets the contract currently being compiled - the most derived one. void setMostDerivedContract(ContractDefinition const& _contract) { m_mostDerivedContract = &_contract; } ContractDefinition const& mostDerivedContract() const; void setArithmetic(Arithmetic _value) { m_arithmetic = _value; } Arithmetic arithmetic() const { return m_arithmetic; } /// @returns the next function in the queue of functions that are still to be compiled /// (i.e. that were referenced during compilation but where we did not yet generate code for). /// Returns nullptr if the queue is empty. Does not remove the function from the queue, /// that will only be done by startFunction below. Declaration const* nextFunctionToCompile() const; /// Resets function specific members, inserts the function entry label and marks the function /// as "having code". void startFunction(Declaration const& _function); /// Appends a call to the named low-level function and inserts the generator into the /// list of low-level-functions to be generated, unless it already exists. /// Note that the generator should not assume that objects are still alive when it is called, /// unless they are guaranteed to be alive for the whole run of the compiler (AST nodes, for example). void callLowLevelFunction( std::string const& _name, unsigned _inArgs, unsigned _outArgs, std::function const& _generator ); /// Appends a call to a yul function and registers the function as externally used. void callYulFunction( std::string const& _name, unsigned _inArgs, unsigned _outArgs ); /// Returns the tag of the named low-level function and inserts the generator into the /// list of low-level-functions to be generated, unless it already exists. /// Note that the generator should not assume that objects are still alive when it is called, /// unless they are guaranteed to be alive for the whole run of the compiler (AST nodes, for example). evmasm::AssemblyItem lowLevelFunctionTag( std::string const& _name, unsigned _inArgs, unsigned _outArgs, std::function const& _generator ); /// Generates the code for missing low-level functions, i.e. calls the generators passed above. void appendMissingLowLevelFunctions(); ABIFunctions& abiFunctions() { return m_abiFunctions; } YulUtilFunctions& utilFunctions() { return m_yulUtilFunctions; } /// Appends concatenation of all generated Yul functions to the bytecode /// and stores the Yul source code to be returned by @a generatedYulUtilityCode. /// Should be called exactly once on each context. void appendYulUtilityFunctions(OptimiserSettings const& _optimiserSettings); bool appendYulUtilityFunctionsRan() const { return m_appendYulUtilityFunctionsRan; } std::string const& generatedYulUtilityCode() const { return m_generatedYulUtilityCode; } static std::string yulUtilityFileName() { return "#utility.yul"; } /// Returns the distance of the given local variable from the bottom of the stack (of the current function). unsigned baseStackOffsetOfVariable(Declaration const& _declaration) const; /// If supplied by a value returned by @ref baseStackOffsetOfVariable(variable), returns /// the distance of that variable from the current top of the stack. unsigned baseToCurrentStackOffset(unsigned _baseOffset) const; /// Converts an offset relative to the current stack height to a value that can be used later /// with baseToCurrentStackOffset to point to the same stack element. unsigned currentToBaseStackOffset(unsigned _offset) const; /// @returns pair of slot and byte offset of the value inside this slot. std::pair storageLocationOfVariable(Declaration const& _declaration) const; /// Appends a JUMPI instruction to a new tag and @returns the tag evmasm::AssemblyItem appendConditionalJump() { return m_asm->appendJumpI().tag(); } /// Appends a JUMPI instruction to @a _tag CompilerContext& appendConditionalJumpTo(evmasm::AssemblyItem const& _tag) { m_asm->appendJumpI(_tag); return *this; } /// Appends a JUMP to a new tag and @returns the tag evmasm::AssemblyItem appendJumpToNew() { return m_asm->appendJump().tag(); } /// Appends a JUMP to a tag already on the stack CompilerContext& appendJump(evmasm::AssemblyItem::JumpType _jumpType = evmasm::AssemblyItem::JumpType::Ordinary); /// Appends code to revert with a Panic(uint256) error. CompilerContext& appendPanic(util::PanicCode _code); /// Appends code to revert with a Panic(uint256) error if the topmost stack element is nonzero. CompilerContext& appendConditionalPanic(util::PanicCode _code); /// Appends a REVERT(0, 0) call /// @param _message is an optional revert message used in debug mode CompilerContext& appendRevert(std::string const& _message = ""); /// Appends a conditional REVERT-call, either forwarding the RETURNDATA or providing the /// empty string. Consumes the condition. /// If the current EVM version does not support RETURNDATA, uses REVERT but does not forward /// the data. /// @param _message is an optional revert message used in debug mode CompilerContext& appendConditionalRevert(bool _forwardReturnData = false, std::string const& _message = ""); /// Appends a JUMP to a specific tag CompilerContext& appendJumpTo( evmasm::AssemblyItem const& _tag, evmasm::AssemblyItem::JumpType _jumpType = evmasm::AssemblyItem::JumpType::Ordinary ) { *m_asm << _tag.pushTag(); return appendJump(_jumpType); } /// Appends pushing of a new tag and @returns the new tag. evmasm::AssemblyItem pushNewTag() { return m_asm->append(m_asm->newPushTag()).tag(); } /// @returns a new tag without pushing any opcodes or data evmasm::AssemblyItem newTag() { return m_asm->newTag(); } /// @returns a new tag identified by name. evmasm::AssemblyItem namedTag(std::string const& _name, size_t _params, size_t _returns, std::optional _sourceID) { return m_asm->namedTag(_name, _params, _returns, _sourceID); } /// Adds a subroutine to the code (in the data section) and pushes its size (via a tag) /// on the stack. @returns the pushsub assembly item. evmasm::AssemblyItem addSubroutine(evmasm::AssemblyPointer const& _assembly) { return m_asm->appendSubroutine(_assembly); } /// Pushes the size of the subroutine. void pushSubroutineSize(size_t _subRoutine) { m_asm->pushSubroutineSize(_subRoutine); } /// Pushes the offset of the subroutine. void pushSubroutineOffset(size_t _subRoutine) { m_asm->pushSubroutineOffset(_subRoutine); } /// Pushes the size of the final program void appendProgramSize() { m_asm->appendProgramSize(); } /// Adds data to the data section, pushes a reference to the stack evmasm::AssemblyItem appendData(bytes const& _data) { return m_asm->append(_data); } /// Appends the address (virtual, will be filled in by linker) of a library. void appendLibraryAddress(std::string const& _identifier) { m_asm->appendLibraryAddress(_identifier); } /// Appends an immutable variable. The value will be filled in by the constructor. void appendImmutable(std::string const& _identifier) { m_asm->appendImmutable(_identifier); } /// Appends an assignment to an immutable variable. Only valid in creation code. void appendImmutableAssignment(std::string const& _identifier) { m_asm->appendImmutableAssignment(_identifier); } /// Appends a zero-address that can be replaced by something else at deploy time (if the /// position in bytecode is known). void appendDeployTimeAddress() { m_asm->append(evmasm::PushDeployTimeAddress); } /// Resets the stack of visited nodes with a new stack having only @c _node void resetVisitedNodes(ASTNode const* _node); /// Pops the stack of visited nodes void popVisitedNodes() { m_visitedNodes.pop(); updateSourceLocation(); } /// Pushes an ASTNode to the stack of visited nodes void pushVisitedNodes(ASTNode const* _node) { m_visitedNodes.push(_node); updateSourceLocation(); } /// Append elements to the current instruction list and adjust @a m_stackOffset. CompilerContext& operator<<(evmasm::AssemblyItem const& _item) { m_asm->append(_item); return *this; } CompilerContext& operator<<(evmasm::Instruction _instruction) { m_asm->append(_instruction); return *this; } CompilerContext& operator<<(u256 const& _value) { m_asm->append(_value); return *this; } CompilerContext& operator<<(bytes const& _data) { m_asm->append(_data); return *this; } /// Appends inline assembly (strict-EVM dialect for the current version). /// @param _assembly the assembly text, should be a block. /// @param _localVariables assigns stack positions to variables with the last one being the stack top /// @param _externallyUsedFunctions a set of function names that are not to be renamed or removed. /// @param _system if true, this is a "system-level" assembly where all functions use named labels /// and the code is marked to be exported as "compiler-generated assembly utility file". /// @param _optimiserSettings settings for the Yul optimiser, which is run in this function already. /// @param _sourceName the name of the assembly file to be used for source locations void appendInlineAssembly( std::string const& _assembly, std::vector const& _localVariables = std::vector(), std::set const& _externallyUsedFunctions = std::set(), bool _system = false, OptimiserSettings const& _optimiserSettings = OptimiserSettings::none(), std::string _sourceName = "--CODEGEN--" ); /// If m_revertStrings is debug, @returns inline assembly code that /// stores @param _message at the free memory pointer and reverts. /// Otherwise returns "revert(0, 0)". std::string revertReasonIfDebug(std::string const& _message = ""); void optimizeYul(yul::Object& _object, yul::EVMDialect const& _dialect, OptimiserSettings const& _optimiserSetting, std::set const& _externalIdentifiers = {}); /// Appends arbitrary data to the end of the bytecode. void appendAuxiliaryData(bytes const& _data) { m_asm->appendAuxiliaryDataToEnd(_data); } /// Run optimisation step. void optimise(OptimiserSettings const& _settings) { m_asm->optimise(translateOptimiserSettings(_settings)); } /// @returns the runtime context if in creation mode and runtime context is set, nullptr otherwise. CompilerContext* runtimeContext() const { return m_runtimeContext; } /// @returns the identifier of the runtime subroutine. size_t runtimeSub() const { return m_runtimeSub; } /// @returns a const reference to the underlying assembly. evmasm::Assembly const& assembly() const { return *m_asm; } /// @returns a shared pointer to the assembly. /// Should be avoided except when adding sub-assemblies. std::shared_ptr assemblyPtr() const { return m_asm; } /** * Helper class to pop the visited nodes stack when a scope closes */ class LocationSetter: public ScopeGuard { public: LocationSetter(CompilerContext& _compilerContext, ASTNode const& _node): ScopeGuard([&]{ _compilerContext.popVisitedNodes(); }) { _compilerContext.pushVisitedNodes(&_node); } }; void setModifierDepth(size_t _modifierDepth) { m_asm->m_currentModifierDepth = _modifierDepth; } RevertStrings revertStrings() const { return m_revertStrings; } private: /// Updates source location set in the assembly. void updateSourceLocation(); evmasm::Assembly::OptimiserSettings translateOptimiserSettings(OptimiserSettings const& _settings); /** * Helper class that manages function labels and ensures that referenced functions are * compiled in a specific order. */ struct FunctionCompilationQueue { /// @returns the entry label of the given function and creates it if it does not exist yet. /// @param _context compiler context used to create a new tag if needed evmasm::AssemblyItem entryLabel(Declaration const& _declaration, CompilerContext& _context); /// @returns the entry label of the given function. Might return an AssemblyItem of type /// UndefinedItem if it does not exist yet. evmasm::AssemblyItem entryLabelIfExists(Declaration const& _declaration) const; /// @returns the next function in the queue of functions that are still to be compiled /// (i.e. that were referenced during compilation but where we did not yet generate code for). /// Returns nullptr if the queue is empty. Does not remove the function from the queue, /// that will only be done by startFunction below. Declaration const* nextFunctionToCompile() const; /// Informs the queue that we are about to compile the given function, i.e. removes /// the function from the queue of functions to compile. void startFunction(Declaration const& _function); /// Labels pointing to the entry points of functions. std::map m_entryLabels; /// Set of functions for which we did not yet generate code. std::set m_alreadyCompiledFunctions; /// Queue of functions that still need to be compiled (important to be a queue to maintain /// determinism even in the presence of a non-deterministic allocator). /// Mutable because we will throw out some functions earlier than needed. mutable std::queue m_functionsToCompile; } m_functionCompilationQueue; evmasm::AssemblyPointer m_asm; /// Version of the EVM to compile against. langutil::EVMVersion m_evmVersion; RevertStrings const m_revertStrings; bool m_useABICoderV2 = false; /// Other already compiled contracts to be used in contract creation calls. std::map> m_otherCompilers; /// Storage offsets of state variables std::map> m_stateVariables; /// Memory offsets reserved for the values of immutable variables during contract creation. std::map m_immutableVariables; /// Total amount of reserved memory. Reserved memory is used to store immutable variables during contract creation. /// This has to be finalized before initialiseFreeMemoryPointer() is called. That function /// will reset the optional to verify that. std::optional m_reservedMemory = {0}; /// Offsets of local variables on the stack (relative to stack base). /// This needs to be a stack because if a modifier contains a local variable and this /// modifier is applied twice, the position of the variable needs to be restored /// after the nested modifier is left. std::map> m_localVariables; /// The contract currently being compiled. Virtual function lookup starts from this contarct. ContractDefinition const* m_mostDerivedContract = nullptr; /// Whether to use checked arithmetic. Arithmetic m_arithmetic = Arithmetic::Checked; /// Stack of current visited AST nodes, used for location attachment std::stack m_visitedNodes; /// The runtime context if in Creation mode, this is used for generating tags that would be stored into the storage and then used at runtime. CompilerContext *m_runtimeContext; /// The index of the runtime subroutine. size_t m_runtimeSub = std::numeric_limits::max(); /// An index of low-level function labels by name. std::map m_lowLevelFunctions; /// Collector for yul functions. MultiUseYulFunctionCollector m_yulFunctionCollector; /// Set of externally used yul functions. std::set m_externallyUsedYulFunctions; /// Generated Yul code used as utility. Source references from the bytecode can point here. /// Produced from @a m_yulFunctionCollector. std::string m_generatedYulUtilityCode; /// Container for ABI functions to be generated. ABIFunctions m_abiFunctions; /// Container for Yul Util functions to be generated. YulUtilFunctions m_yulUtilFunctions; /// The queue of low-level functions to generate. std::queue>> m_lowLevelFunctionGenerationQueue; /// Flag to check that appendYulUtilityFunctions() was called exactly once bool m_appendYulUtilityFunctionsRan = false; }; }