path: root/libjulia/backends/evm/EVMCodeTransform.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/>.
*/
/**
 * Common code generator for translating Julia / inline assembly to EVM and EVM1.5.
 */

#include <libjulia/backends/evm/EVMAssembly.h>

#include <libsolidity/inlineasm/AsmStack.h>
#include <libsolidity/inlineasm/AsmScope.h>

#include <boost/variant.hpp>
#include <boost/optional.hpp>

namespace dev
{
namespace solidity
{
class ErrorReporter;
namespace assembly
{
struct Literal;
struct Block;
struct Switch;
struct Label;
struct FunctionalInstruction;
struct Assignment;
struct VariableDeclaration;
struct Instruction;
struct Identifier;
struct StackAssignment;
struct FunctionDefinition;
struct FunctionCall;

using Statement = boost::variant<Instruction, Literal, Label, StackAssignment, Identifier, Assignment, FunctionCall, FunctionalInstruction, VariableDeclaration, FunctionDefinition, Switch, Block>;

struct AsmAnalysisInfo;
}
}
namespace julia
{
class EVMAssembly;

class CodeTransform: public boost::static_visitor<>
{
public:
    /// Create the code transformer.
    /// @param _identifierAccess used to resolve identifiers external to the inline assembly
    CodeTransform(
        julia::AbstractAssembly& _assembly,
        solidity::assembly::AsmAnalysisInfo& _analysisInfo,
        bool _evm15 = false,
        ExternalIdentifierAccess const& _identifierAccess = ExternalIdentifierAccess()
    ): CodeTransform(_assembly, _analysisInfo, _evm15, _identifierAccess, _assembly.stackHeight())
    {
    }

    /// Processes the block and appends the resulting code to the assembly.
    void run(solidity::assembly::Block const& _block);

protected:
    CodeTransform(
        julia::AbstractAssembly& _assembly,
        solidity::assembly::AsmAnalysisInfo& _analysisInfo,
        bool _evm15,
        ExternalIdentifierAccess const& _identifierAccess,
        int _stackAdjustment
    ):
        m_assembly(_assembly),
        m_info(_analysisInfo),
        m_evm15(_evm15),
        m_identifierAccess(_identifierAccess),
        m_stackAdjustment(_stackAdjustment)
    {}

public:
    void operator()(solidity::assembly::Instruction const& _instruction);
    void operator()(solidity::assembly::Literal const& _literal);
    void operator()(solidity::assembly::Identifier const& _identifier);
    void operator()(solidity::assembly::FunctionalInstruction const& _instr);
    void operator()(solidity::assembly::FunctionCall const&);
    void operator()(solidity::assembly::Label const& _label);
    void operator()(solidity::assembly::StackAssignment const& _assignment);
    void operator()(solidity::assembly::Assignment const& _assignment);
    void operator()(solidity::assembly::VariableDeclaration const& _varDecl);
    void operator()(solidity::assembly::Switch const& _switch);
    void operator()(solidity::assembly::FunctionDefinition const&);
    void operator()(solidity::assembly::Block const& _block);

private:
    AbstractAssembly::LabelID labelFromIdentifier(solidity::assembly::Identifier const& _identifier);
    /// Generates code for an expression that is supposed to return a single value.
    void visitExpression(solidity::assembly::Statement const& _expression);

    void generateAssignment(solidity::assembly::Identifier const& _variableName);

    /// Determines the stack height difference to the given variables. Throws
    /// if it is not yet in scope or the height difference is too large. Returns
    /// the (positive) stack height difference otherwise.
    int variableHeightDiff(solidity::assembly::Scope::Variable const& _var, bool _forSwap);

    void expectDeposit(int _deposit, int _oldHeight);

    void checkStackHeight(void const* _astElement);

    /// Assigns the label's or function's id to a value taken from eth::Assembly if it has not yet been set.
    void assignLabelIdIfUnset(boost::optional<AbstractAssembly::LabelID>& _labelId);

    julia::AbstractAssembly& m_assembly;
    solidity::assembly::AsmAnalysisInfo& m_info;
    solidity::assembly::Scope* m_scope = nullptr;
    bool m_evm15 = false;
    ExternalIdentifierAccess m_identifierAccess;
    /// Adjustment between the stack height as determined during the analysis phase
    /// and the stack height in the assembly. This is caused by an initial stack being present
    /// for inline assembly and different stack heights depending on the EVM backend used
    /// (EVM 1.0 or 1.5).
    int m_stackAdjustment = 0;
};

}
}