solidity/libsolidity/analysis/TypeChecker.h
2019-09-23 17:22:56 +02:00

176 lines
7.0 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/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2015
* Type analyzer and checker.
*/
#pragma once
#include <liblangutil/EVMVersion.h>
#include <libsolidity/ast/ASTAnnotations.h>
#include <libsolidity/ast/ASTForward.h>
#include <libsolidity/ast/ASTVisitor.h>
#include <libsolidity/ast/Types.h>
namespace langutil
{
class ErrorReporter;
}
namespace dev
{
namespace solidity
{
/**
* The module that performs type analysis on the AST, checks the applicability of operations on
* those types and stores errors for invalid operations.
* Provides a way to retrieve the type of an AST node.
*/
class TypeChecker: private ASTConstVisitor
{
public:
/// @param _errorReporter provides the error logging functionality.
TypeChecker(langutil::EVMVersion _evmVersion, langutil::ErrorReporter& _errorReporter):
m_evmVersion(_evmVersion),
m_errorReporter(_errorReporter)
{}
/// Performs type checking on the given contract and all of its sub-nodes.
/// @returns true iff all checks passed. Note even if all checks passed, errors() can still contain warnings
bool checkTypeRequirements(ASTNode const& _contract);
/// @returns the type of an expression and asserts that it is present.
TypePointer const& type(Expression const& _expression) const;
/// @returns the type of the given variable and throws if the type is not present
/// (this can happen for variables with non-explicit types before their types are resolved)
TypePointer const& type(VariableDeclaration const& _variable) const;
static bool typeSupportedByOldABIEncoder(Type const& _type, bool _isLibraryCall);
private:
bool visit(ContractDefinition const& _contract) override;
/// Checks (and warns) if a tuple assignment might cause unexpected overwrites in storage.
/// Should only be called if the left hand side is tuple-typed.
void checkDoubleStorageAssignment(Assignment const& _assignment);
// Checks whether the expression @arg _expression can be assigned from type @arg _type
// and reports an error, if not.
void checkExpressionAssignment(Type const& _type, Expression const& _expression);
/// Performs type checks for ``abi.decode(bytes memory, (...))`` and returns the
/// vector of return types (which is basically the second argument) if successful. It returns
/// the empty vector on error.
TypePointers typeCheckABIDecodeAndRetrieveReturnType(
FunctionCall const& _functionCall,
bool _abiEncoderV2
);
TypePointers typeCheckMetaTypeFunctionAndRetrieveReturnType(FunctionCall const& _functionCall);
/// Performs type checks and determines result types for type conversion FunctionCall nodes.
TypePointer typeCheckTypeConversionAndRetrieveReturnType(
FunctionCall const& _functionCall
);
/// Performs type checks on function call and struct ctor FunctionCall nodes (except for kind ABIDecode).
void typeCheckFunctionCall(
FunctionCall const& _functionCall,
FunctionTypePointer _functionType
);
/// Performs general number and type checks of arguments against function call and struct ctor FunctionCall node parameters.
void typeCheckFunctionGeneralChecks(
FunctionCall const& _functionCall,
FunctionTypePointer _functionType
);
/// Performs general checks and checks specific to ABI encode functions
void typeCheckABIEncodeFunctions(
FunctionCall const& _functionCall,
FunctionTypePointer _functionType
);
void endVisit(InheritanceSpecifier const& _inheritance) override;
void endVisit(UsingForDirective const& _usingFor) override;
bool visit(StructDefinition const& _struct) override;
bool visit(FunctionDefinition const& _function) override;
bool visit(VariableDeclaration const& _variable) override;
/// We need to do this manually because we want to pass the bases of the current contract in
/// case this is a base constructor call.
void visitManually(ModifierInvocation const& _modifier, std::vector<ContractDefinition const*> const& _bases);
bool visit(EventDefinition const& _eventDef) override;
void endVisit(FunctionTypeName const& _funType) override;
bool visit(InlineAssembly const& _inlineAssembly) override;
bool visit(IfStatement const& _ifStatement) override;
void endVisit(TryStatement const& _tryStatement) override;
bool visit(WhileStatement const& _whileStatement) override;
bool visit(ForStatement const& _forStatement) override;
void endVisit(Return const& _return) override;
bool visit(EmitStatement const&) override { m_insideEmitStatement = true; return true; }
void endVisit(EmitStatement const& _emit) override;
bool visit(VariableDeclarationStatement const& _variable) override;
void endVisit(ExpressionStatement const& _statement) override;
bool visit(Conditional const& _conditional) override;
bool visit(Assignment const& _assignment) override;
bool visit(TupleExpression const& _tuple) override;
void endVisit(BinaryOperation const& _operation) override;
bool visit(UnaryOperation const& _operation) override;
bool visit(FunctionCall const& _functionCall) override;
void endVisit(NewExpression const& _newExpression) override;
bool visit(MemberAccess const& _memberAccess) override;
bool visit(IndexAccess const& _indexAccess) override;
bool visit(IndexRangeAccess const& _indexRangeAccess) override;
bool visit(Identifier const& _identifier) override;
void endVisit(ElementaryTypeNameExpression const& _expr) override;
void endVisit(Literal const& _literal) override;
bool contractDependenciesAreCyclic(
ContractDefinition const& _contract,
std::set<ContractDefinition const*> const& _seenContracts = std::set<ContractDefinition const*>()
) const;
/// @returns the referenced declaration and throws on error.
Declaration const& dereference(Identifier const& _identifier) const;
/// @returns the referenced declaration and throws on error.
Declaration const& dereference(UserDefinedTypeName const& _typeName) const;
/// Runs type checks on @a _expression to infer its type and then checks that it is implicitly
/// convertible to @a _expectedType.
bool expectType(Expression const& _expression, Type const& _expectedType);
/// Runs type checks on @a _expression to infer its type and then checks that it is an LValue.
void requireLValue(Expression const& _expression);
ContractDefinition const* m_scope = nullptr;
langutil::EVMVersion m_evmVersion;
/// Flag indicating whether we are currently inside an EmitStatement.
bool m_insideEmitStatement = false;
/// Flag indicating whether we are currently inside a StructDefinition.
bool m_insideStruct = false;
langutil::ErrorReporter& m_errorReporter;
};
}
}