path: root/libsolidity/inlineasm/AsmAnalysis.h

/*
    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/>.
*/
/**
 * Analysis part of inline assembly.
 */

#pragma once

#include <libsolidity/inlineasm/AsmStack.h>

#include <libsolidity/interface/Exceptions.h>

#include <boost/variant.hpp>

#include <functional>
#include <memory>

namespace dev
{
namespace solidity
{
namespace assembly
{

struct Literal;
struct Block;
struct Label;
struct FunctionalInstruction;
struct Assignment;
struct VariableDeclaration;
struct Instruction;
struct Identifier;
struct StackAssignment;
struct FunctionDefinition;
struct FunctionCall;
struct Switch;

struct Scope;

struct AsmAnalysisInfo;

/**
 * Performs the full analysis stage, calls the ScopeFiller internally, then resolves
 * references and performs other checks.
 * If all these checks pass, code generation should not throw errors.
 */
class AsmAnalyzer: public boost::static_visitor<bool>
{
public:
    AsmAnalyzer(
        AsmAnalysisInfo& _analysisInfo,
        ErrorList& _errors,
        ExternalIdentifierAccess::Resolver const& _resolver = ExternalIdentifierAccess::Resolver()
    );

    bool analyze(assembly::Block const& _block);

    bool operator()(assembly::Instruction const&);
    bool operator()(assembly::Literal const& _literal);
    bool operator()(assembly::Identifier const&);
    bool operator()(assembly::FunctionalInstruction const& _functionalInstruction);
    bool operator()(assembly::Label const& _label);
    bool operator()(assembly::StackAssignment const&);
    bool operator()(assembly::Assignment const& _assignment);
    bool operator()(assembly::VariableDeclaration const& _variableDeclaration);
    bool operator()(assembly::FunctionDefinition const& _functionDefinition);
    bool operator()(assembly::FunctionCall const& _functionCall);
    bool operator()(assembly::Switch const& _switch);
    bool operator()(assembly::Block const& _block);

private:
    /// Verifies that a variable to be assigned to exists and has the same size
    /// as the value, @a _valueSize, unless that is equal to -1.
    bool checkAssignment(assembly::Identifier const& _assignment, size_t _valueSize = size_t(-1));
    bool expectDeposit(int _deposit, int _oldHeight, SourceLocation const& _location);
    Scope& scope(assembly::Block const* _block);

    /// This is used when we enter the body of a function definition. There, the parameters
    /// and return parameters appear as variables which are already on the stack before
    /// we enter the block.
    int m_virtualVariablesInNextBlock = 0;
    int m_stackHeight = 0;
    ExternalIdentifierAccess::Resolver const& m_resolver;
    Scope* m_currentScope = nullptr;
    AsmAnalysisInfo& m_info;
    ErrorList& m_errors;
};

}
}
}