include/lldb/Expression/Expression.h

//===-- Expression.h --------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_Expression_h_
#define liblldb_Expression_h_

// C Includes
// C++ Includes
#include <string>
#include <map>
#include <vector>

// Other libraries and framework includes
// Project includes

#include "lldb/lldb-forward.h"
#include "lldb/lldb-private.h"
#include "lldb/Expression/ExpressionTypeSystemHelper.h"

namespace lldb_private {

class RecordingMemoryManager;

//----------------------------------------------------------------------
/// @class Expression Expression.h "lldb/Expression/Expression.h"
/// @brief Encapsulates a single expression for use in lldb
///
/// LLDB uses expressions for various purposes, notably to call functions
/// and as a backend for the expr command.  Expression encapsulates
/// the objects needed to parse and interpret or JIT an expression.  It
/// uses the expression parser appropriate to the language of the expression
/// to produce LLVM IR from the expression.
//----------------------------------------------------------------------
class Expression
{
public:
    enum ResultType {
        eResultTypeAny,
        eResultTypeId
    };
    
    Expression (Target &target);
    
    Expression (ExecutionContextScope &exe_scope);
    
    //------------------------------------------------------------------
    /// Destructor
    //------------------------------------------------------------------
    virtual ~Expression ()
    {
    }
    
    //------------------------------------------------------------------
    /// Return the string that the parser should parse.  Must be a full
    /// translation unit.
    //------------------------------------------------------------------
    virtual const char *
    Text () = 0;
    
    //------------------------------------------------------------------
    /// Return the function name that should be used for executing the
    /// expression.  Text() should contain the definition of this
    /// function.
    //------------------------------------------------------------------
    virtual const char *
    FunctionName () = 0;
    
    //------------------------------------------------------------------
    /// Return the language that should be used when parsing.  To use
    /// the default, return eLanguageTypeUnknown.
    //------------------------------------------------------------------
    virtual lldb::LanguageType
    Language ()
    {
        return lldb::eLanguageTypeUnknown;
    }
    
    //------------------------------------------------------------------
    /// Return the desired result type of the function, or 
    /// eResultTypeAny if indifferent.
    //------------------------------------------------------------------
    virtual ResultType
    DesiredResultType ()
    {
        return eResultTypeAny;
    }
    
    //------------------------------------------------------------------
    /// Flags
    //------------------------------------------------------------------
    
    //------------------------------------------------------------------
    /// Return true if validation code should be inserted into the
    /// expression.
    //------------------------------------------------------------------
    virtual bool
    NeedsValidation () = 0;
    
    //------------------------------------------------------------------
    /// Return true if external variables in the expression should be
    /// resolved.
    //------------------------------------------------------------------
    virtual bool
    NeedsVariableResolution () = 0;

    virtual EvaluateExpressionOptions *GetOptions() { return nullptr; };

    //------------------------------------------------------------------
    /// Return the address of the function's JIT-compiled code, or
    /// LLDB_INVALID_ADDRESS if the function is not JIT compiled
    //------------------------------------------------------------------
    lldb::addr_t
    StartAddress ()
    {
        return m_jit_start_addr;
    }
    
    virtual ExpressionTypeSystemHelper *
    GetTypeSystemHelper ()
    {
        return nullptr;
    }

protected:

    lldb::TargetWP  m_target_wp;            /// Expression's always have to have a target...
    lldb::ProcessWP m_jit_process_wp;       /// An expression might have a process, but it doesn't need to (e.g. calculator mode.)
    lldb::addr_t    m_jit_start_addr;       ///< The address of the JITted function within the JIT allocation.  LLDB_INVALID_ADDRESS if invalid.
    lldb::addr_t    m_jit_end_addr;         ///< The address of the JITted function within the JIT allocation.  LLDB_INVALID_ADDRESS if invalid.

};

} // namespace lldb_private

#endif  // liblldb_Expression_h_