solidity/libsolidity/codegen/ir/IRGeneratorForStatements.h
2021-06-23 16:15:25 +02:00

231 lines
8.9 KiB
C++

/*
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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* Component that translates Solidity code into Yul at statement level and below.
*/
#pragma once
#include <libsolidity/ast/ASTVisitor.h>
#include <libsolidity/codegen/ir/IRLValue.h>
#include <libsolidity/codegen/ir/IRVariable.h>
#include <functional>
namespace solidity::frontend
{
class IRGenerationContext;
class YulUtilFunctions;
/**
* Base class for the statement generator.
* Encapsulates access to the yul code stream and handles source code locations.
*/
class IRGeneratorForStatementsBase: public ASTConstVisitor
{
public:
IRGeneratorForStatementsBase(IRGenerationContext& _context):
m_context(_context)
{}
virtual std::string code() const;
std::ostringstream& appendCode(bool _addLocationComment = true);
protected:
void setLocation(ASTNode const& _node);
langutil::SourceLocation m_currentLocation = {};
langutil::SourceLocation m_lastLocation = {};
IRGenerationContext& m_context;
private:
std::ostringstream m_code;
};
/**
* Component that translates Solidity's AST into Yul at statement level and below.
* It is an AST visitor that appends to an internal string buffer.
*/
class IRGeneratorForStatements: public IRGeneratorForStatementsBase
{
public:
IRGeneratorForStatements(
IRGenerationContext& _context,
YulUtilFunctions& _utils,
std::function<std::string()> _placeholderCallback = {}
):
IRGeneratorForStatementsBase(_context),
m_placeholderCallback(std::move(_placeholderCallback)),
m_utils(_utils)
{}
std::string code() const override;
/// Generate the code for the statements in the block;
void generate(Block const& _block);
/// Generates code to initialize the given state variable.
void initializeStateVar(VariableDeclaration const& _varDecl);
/// Generates code to initialize the given local variable.
void initializeLocalVar(VariableDeclaration const& _varDecl);
/// Calculates expression's value and returns variable where it was stored
IRVariable evaluateExpression(Expression const& _expression, Type const& _to);
/// Defines @a _var using the value of @a _value while performing type conversions, if required.
void define(IRVariable const& _var, IRVariable const& _value) { declareAssign(_var, _value, true); }
/// @returns the name of a function that computes the value of the given constant
/// and also generates the function.
std::string constantValueFunction(VariableDeclaration const& _constant);
void endVisit(VariableDeclarationStatement const& _variableDeclaration) override;
bool visit(Conditional const& _conditional) override;
bool visit(Assignment const& _assignment) override;
bool visit(TupleExpression const& _tuple) override;
void endVisit(PlaceholderStatement const& _placeholder) override;
bool visit(Block const& _block) override;
void endVisit(Block const& _block) override;
bool visit(IfStatement const& _ifStatement) override;
bool visit(ForStatement const& _forStatement) override;
bool visit(WhileStatement const& _whileStatement) override;
bool visit(Continue const& _continueStatement) override;
bool visit(Break const& _breakStatement) override;
void endVisit(Return const& _return) override;
void endVisit(UnaryOperation const& _unaryOperation) override;
bool visit(BinaryOperation const& _binOp) override;
void endVisit(FunctionCall const& _funCall) override;
void endVisit(FunctionCallOptions const& _funCallOptions) override;
bool visit(MemberAccess const& _memberAccess) override;
void endVisit(MemberAccess const& _memberAccess) override;
bool visit(InlineAssembly const& _inlineAsm) override;
void endVisit(IndexAccess const& _indexAccess) override;
void endVisit(IndexRangeAccess const& _indexRangeAccess) override;
void endVisit(Identifier const& _identifier) override;
bool visit(Literal const& _literal) override;
bool visit(TryStatement const& _tryStatement) override;
bool visit(TryCatchClause const& _tryCatchClause) override;
private:
/// Handles all catch cases of a try statement, except the success-case.
void handleCatch(TryStatement const& _tryStatement);
void handleCatchFallback(TryCatchClause const& _fallback);
/// Generates code to revert with an error. The error arguments are assumed to
/// be already evaluated and available in local IRVariables, but not yet
/// converted.
void revertWithError(
std::string const& _signature,
std::vector<Type const*> const& _parameterTypes,
std::vector<ASTPointer<Expression const>> const& _errorArguments
);
void handleVariableReference(
VariableDeclaration const& _variable,
Expression const& _referencingExpression
);
/// Appends code to call an external function with the given arguments.
/// All involved expressions have already been visited.
void appendExternalFunctionCall(
FunctionCall const& _functionCall,
std::vector<ASTPointer<Expression const>> const& _arguments
);
/// Appends code for .call / .delegatecall / .staticcall.
/// All involved expressions have already been visited.
void appendBareCall(
FunctionCall const& _functionCall,
std::vector<ASTPointer<Expression const>> const& _arguments
);
/// Requests and assigns the internal ID of the referenced function to the referencing
/// expression and adds the function to the internal dispatch.
/// If the function is called right away, it does nothing.
void assignInternalFunctionIDIfNotCalledDirectly(
Expression const& _expression,
FunctionDefinition const& _referencedFunction
);
/// Generates the required conversion code and @returns an IRVariable referring to the value of @a _variable
/// converted to type @a _to.
IRVariable convert(IRVariable const& _variable, Type const& _to);
/// @returns a Yul expression representing the current value of @a _expression,
/// converted to type @a _to if it does not yet have that type.
/// If @a _forceCleanup is set to true, it also cleans the value, in case it already has type @a _to.
std::string expressionAsType(Expression const& _expression, Type const& _to, bool _forceCleanup = false);
/// @returns an output stream that can be used to define @a _var using a function call or
/// single stack slot expression.
std::ostream& define(IRVariable const& _var);
/// Assigns @a _var to the value of @a _value while performing type conversions, if required.
void assign(IRVariable const& _var, IRVariable const& _value) { declareAssign(_var, _value, false); }
/// Declares variable @a _var.
void declare(IRVariable const& _var);
void declareAssign(IRVariable const& _var, IRVariable const& _value, bool _define);
/// @returns an IRVariable with the zero
/// value of @a _type.
/// @param _splitFunctionTypes if false, returns two zeroes
IRVariable zeroValue(Type const& _type, bool _splitFunctionTypes = true);
void appendAndOrOperatorCode(BinaryOperation const& _binOp);
void appendSimpleUnaryOperation(UnaryOperation const& _operation, Expression const& _expr);
/// @returns code to perform the given binary operation in the given type on the two values.
std::string binaryOperation(
langutil::Token _op,
Type const& _type,
std::string const& _left,
std::string const& _right
);
/// @returns code to perform the given shift operation.
/// The operation itself will be performed in the type of the value,
/// while the amount to shift can have its own type.
std::string shiftOperation(langutil::Token _op, IRVariable const& _value, IRVariable const& _shiftAmount);
/// Assigns the value of @a _value to the lvalue @a _lvalue.
void writeToLValue(IRLValue const& _lvalue, IRVariable const& _value);
/// @returns a fresh IR variable containing the value of the lvalue @a _lvalue.
IRVariable readFromLValue(IRLValue const& _lvalue);
/// Stores the given @a _lvalue in m_currentLValue, if it will be written to (willBeWrittenTo). Otherwise
/// defines the expression @a _expression by reading the value from @a _lvalue.
void setLValue(Expression const& _expression, IRLValue _lvalue);
void generateLoop(
Statement const& _body,
Expression const* _conditionExpression,
Statement const* _initExpression = nullptr,
ExpressionStatement const* _loopExpression = nullptr,
bool _isDoWhile = false
);
static Type const& type(Expression const& _expression);
std::string linkerSymbol(ContractDefinition const& _library) const;
std::function<std::string()> m_placeholderCallback;
YulUtilFunctions& m_utils;
std::optional<IRLValue> m_currentLValue;
};
}