/*
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 <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2014
* Utilities for the solidity compiler.
*/
#pragma once
#include <libsolidity/codegen/ABIFunctions.h>
#include <libsolidity/interface/EVMVersion.h>
#include <libsolidity/ast/ASTForward.h>
#include <libsolidity/ast/Types.h>
#include <libsolidity/ast/ASTAnnotations.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/Assembly.h>
#include <libdevcore/Common.h>
#include <ostream>
#include <stack>
#include <queue>
#include <utility>
#include <functional>
namespace dev {
namespace solidity {
/**
* 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(EVMVersion _evmVersion = EVMVersion{}, CompilerContext* _runtimeContext = nullptr):
m_asm(std::make_shared<eth::Assembly>()),
m_evmVersion(_evmVersion),
m_runtimeContext(_runtimeContext),
m_abiFunctions(m_evmVersion)
{
if (m_runtimeContext)
m_runtimeSub = size_t(m_asm->newSub(m_runtimeContext->m_asm).data());
}
EVMVersion const& evmVersion() const { return m_evmVersion; }
/// Update currently enabled set of experimental features.
void setExperimentalFeatures(std::set<ExperimentalFeature> const& _features) { m_experimentalFeatures = _features; }
/// @returns true if the given feature is enabled.
bool experimentalFeatureActive(ExperimentalFeature _feature) const { return m_experimentalFeatures.count(_feature); }
void addStateVariable(VariableDeclaration const& _declaration, u256 const& _storageOffset, unsigned _byteOffset);
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 setCompiledContracts(std::map<ContractDefinition const*, eth::Assembly const*> const& _contracts) { m_compiledContracts = _contracts; }
eth::Assembly const& compiledContract(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.
eth::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.
eth::AssemblyItem functionEntryLabelIfExists(Declaration const& _declaration) const;
/// @returns the entry label of the given function and takes overrides into account.
FunctionDefinition const& resolveVirtualFunction(FunctionDefinition const& _function);
/// @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);
/// @returns the next constructor in the inheritance hierarchy.
FunctionDefinition const* nextConstructor(ContractDefinition const& _contract) const;
/// Sets the current inheritance hierarchy from derived to base.
void setInheritanceHierarchy(std::vector<ContractDefinition const*> const& _hierarchy) { m_inheritanceHierarchy = _hierarchy; }
/// @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<void(CompilerContext&)> const& _generator
);
/// 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).
eth::AssemblyItem lowLevelFunctionTag(
std::string const& _name,
unsigned _inArgs,
unsigned _outArgs,
std::function<void(CompilerContext&)> const& _generator
);
/// Generates the code for missing low-level functions, i.e. calls the generators passed above.
void appendMissingLowLevelFunctions();
ABIFunctions& abiFunctions() { return m_abiFunctions; }
ModifierDefinition const& resolveVirtualFunctionModifier(ModifierDefinition const& _modifier) const;
/// 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<u256, unsigned> storageLocationOfVariable(Declaration const& _declaration) const;
/// Appends a JUMPI instruction to a new tag and @returns the tag
eth::AssemblyItem appendConditionalJump() { return m_asm->appendJumpI().tag(); }
/// Appends a JUMPI instruction to @a _tag
CompilerContext& appendConditionalJumpTo(eth::AssemblyItem const& _tag) { m_asm->appendJumpI(_tag); return *this; }
/// Appends a JUMP to a new tag and @returns the tag
eth::AssemblyItem appendJumpToNew() { return m_asm->appendJump().tag(); }
/// Appends a JUMP to a tag already on the stack
CompilerContext& appendJump(eth::AssemblyItem::JumpType _jumpType = eth::AssemblyItem::JumpType::Ordinary);
/// Appends an INVALID instruction
CompilerContext& appendInvalid();
/// Appends a conditional INVALID instruction
CompilerContext& appendConditionalInvalid();
/// Appends a REVERT(0, 0) call
CompilerContext& appendRevert();
/// 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.
CompilerContext& appendConditionalRevert(bool _forwardReturnData = false);
/// Appends a JUMP to a specific tag
CompilerContext& appendJumpTo(eth::AssemblyItem const& _tag) { m_asm->appendJump(_tag); return *this; }
/// Appends pushing of a new tag and @returns the new tag.
eth::AssemblyItem pushNewTag() { return m_asm->append(m_asm->newPushTag()).tag(); }
/// @returns a new tag without pushing any opcodes or data
eth::AssemblyItem newTag() { return m_asm->newTag(); }
/// @returns a new tag identified by name.
eth::AssemblyItem namedTag(std::string const& _name) { return m_asm->namedTag(_name); }
/// 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.
eth::AssemblyItem addSubroutine(eth::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
eth::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 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(eth::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<<(eth::AssemblyItem const& _item) { m_asm->append(_item); return *this; }
CompilerContext& operator<<(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 mode).
/// @a _replacements are string-matching replacements that are performed prior to parsing the inline assembly.
/// @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.
void appendInlineAssembly(
std::string const& _assembly,
std::vector<std::string> const& _localVariables = std::vector<std::string>(),
std::set<std::string> const& _externallyUsedFunctions = std::set<std::string>(),
bool _system = false
);
/// Appends arbitrary data to the end of the bytecode.
void appendAuxiliaryData(bytes const& _data) { m_asm->appendAuxiliaryDataToEnd(_data); }
/// Run optimisation step.
void optimise(bool _fullOptimsation, unsigned _runs = 200) { m_asm->optimise(_fullOptimsation, m_evmVersion, true, _runs); }
/// @returns the runtime context if in creation mode and runtime context is set, nullptr otherwise.
CompilerContext* runtimeContext() { 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.
eth::Assembly const& assembly() const { return *m_asm; }
/// @returns non-const reference to the underlying assembly. Should be avoided in favour of
/// wrappers in this class.
eth::Assembly& nonConstAssembly() { return *m_asm; }
/// @arg _sourceCodes is the map of input files to source code strings
std::string assemblyString(StringMap const& _sourceCodes = StringMap()) const
{
return m_asm->assemblyString(_sourceCodes);
}
/// @arg _sourceCodes is the map of input files to source code strings
Json::Value assemblyJSON(StringMap const& _sourceCodes = StringMap()) const
{
return m_asm->assemblyJSON(_sourceCodes);
}
eth::LinkerObject const& assembledObject() const { return m_asm->assemble(); }
eth::LinkerObject const& assembledRuntimeObject(size_t _subIndex) const { return m_asm->sub(_subIndex).assemble(); }
/**
* 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); }
};
private:
/// Searches the inheritance hierarchy towards the base starting from @a _searchStart and returns
/// the first function definition that is overwritten by _function.
FunctionDefinition const& resolveVirtualFunction(
FunctionDefinition const& _function,
std::vector<ContractDefinition const*>::const_iterator _searchStart
);
/// @returns an iterator to the contract directly above the given contract.
std::vector<ContractDefinition const*>::const_iterator superContract(const ContractDefinition &_contract) const;
/// Updates source location set in the assembly.
void updateSourceLocation();
/**
* 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
eth::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.
eth::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(const Declaration &_function);
/// Labels pointing to the entry points of functions.
std::map<Declaration const*, eth::AssemblyItem> m_entryLabels;
/// Set of functions for which we did not yet generate code.
std::set<Declaration const*> 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<Declaration const*> m_functionsToCompile;
} m_functionCompilationQueue;
eth::AssemblyPointer m_asm;
/// Version of the EVM to compile against.
EVMVersion m_evmVersion;
/// Activated experimental features.
std::set<ExperimentalFeature> m_experimentalFeatures;
/// Other already compiled contracts to be used in contract creation calls.
std::map<ContractDefinition const*, eth::Assembly const*> m_compiledContracts;
/// Storage offsets of state variables
std::map<Declaration const*, std::pair<u256, unsigned>> m_stateVariables;
/// 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<Declaration const*, std::vector<unsigned>> m_localVariables;
/// List of current inheritance hierarchy from derived to base.
std::vector<ContractDefinition const*> m_inheritanceHierarchy;
/// Stack of current visited AST nodes, used for location attachment
std::stack<ASTNode const*> 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 = -1;
/// An index of low-level function labels by name.
std::map<std::string, eth::AssemblyItem> m_lowLevelFunctions;
/// Container for ABI functions to be generated.
ABIFunctions m_abiFunctions;
/// The queue of low-level functions to generate.
std::queue<std::tuple<std::string, unsigned, unsigned, std::function<void(CompilerContext&)>>> m_lowLevelFunctionGenerationQueue;
};
}
}
