//===-- ExpressionParser.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_ExpressionParser_h_
#define liblldb_ExpressionParser_h_

#include "lldb/lldb-public.h"
#include "lldb/Core/Error.h"

namespace lldb_private
{

class IRExecutionUnit;
    
//----------------------------------------------------------------------
/// @class ExpressionParser ExpressionParser.h "lldb/Expression/ExpressionParser.h"
/// @brief Encapsulates an instance of a compiler that can parse expressions.
///
/// ExpressionParser is the base class for llvm based Expression parsers.
//----------------------------------------------------------------------
class ExpressionParser
{
public:
    //------------------------------------------------------------------
    /// Constructor
    ///
    /// Initializes class variables.
    ///
    /// @param[in] exe_scope,
    ///     If non-NULL, an execution context scope that can help to 
    ///     correctly create an expression with a valid process for 
    ///     optional tuning Objective-C runtime support. Can be NULL.
    ///
    /// @param[in] expr
    ///     The expression to be parsed.
    //------------------------------------------------------------------
    ExpressionParser (ExecutionContextScope *exe_scope,
                      Expression &expr,
                      bool generate_debug_info) :
        m_expr(expr),
        m_generate_debug_info(generate_debug_info)
    {
    }
    
    //------------------------------------------------------------------
    /// Destructor
    //------------------------------------------------------------------
    virtual ~ExpressionParser () {};
    
    //------------------------------------------------------------------
    /// Parse a single expression and convert it to IR using Clang.  Don't
    /// wrap the expression in anything at all.
    ///
    /// @param[in] stream
    ///     The stream to print errors to.
    ///
    /// @return
    ///     The number of errors encountered during parsing.  0 means
    ///     success.
    //------------------------------------------------------------------
    virtual unsigned
    Parse (Stream &stream) = 0;
    
    //------------------------------------------------------------------
    /// Ready an already-parsed expression for execution, possibly
    /// evaluating it statically.
    ///
    /// @param[out] func_addr
    ///     The address to which the function has been written.
    ///
    /// @param[out] func_end
    ///     The end of the function's allocated memory region.  (func_addr
    ///     and func_end do not delimit an allocated region; the allocated
    ///     region may begin before func_addr.)
    ///
    /// @param[in] execution_unit_sp
    ///     After parsing, ownership of the execution unit for
    ///     for the expression is handed to this shared pointer.
    ///
    /// @param[in] exe_ctx
    ///     The execution context to write the function into.
    ///
    /// @param[out] can_interpret
    ///     Set to true if the expression could be interpreted statically;
    ///     untouched otherwise.
    ///
    /// @param[in] execution_policy
    ///     Determines whether the expression must be JIT-compiled, must be
    ///     evaluated statically, or whether this decision may be made
    ///     opportunistically.
    ///
    /// @return
    ///     An error code indicating the success or failure of the operation.
    ///     Test with Success().
    //------------------------------------------------------------------
    virtual Error
    PrepareForExecution (lldb::addr_t &func_addr,
                         lldb::addr_t &func_end,
                         std::shared_ptr<IRExecutionUnit> &execution_unit_sp,
                         ExecutionContext &exe_ctx,
                         bool &can_interpret,
                         lldb_private::ExecutionPolicy execution_policy) = 0;
        
    bool
    GetGenerateDebugInfo () const
    {
        return m_generate_debug_info;
    }
    
protected:
    Expression &                       m_expr;                       ///< The expression to be parsed
    bool                               m_generate_debug_info;
};
    
}

#endif  // liblldb_ExpressionParser_h_
