lldb/include/lldb/Expression/IRInterpreter.h

//===-- IRInterpreter.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_IRInterpreter_h_
#define liblldb_IRInterpreter_h_

#include "lldb/lldb-public.h"
#include "lldb/Core/ConstString.h"
#include "lldb/Core/Stream.h"
#include "lldb/Symbol/TaggedASTType.h"
#include "llvm/Pass.h"

namespace llvm {
    class Function;
    class Module;
}

namespace lldb_private {

class ClangExpressionDeclMap;
    
}

//----------------------------------------------------------------------
/// @class IRInterpreter IRInterpreter.h "lldb/Expression/IRInterpreter.h"
/// @brief Attempt to interpret the function's code if it does not require
///        running the target.
///
/// In some cases, the IR for an expression can be evaluated entirely
/// in the debugger, manipulating variables but not executing any code
/// in the target.  The IRInterpreter attempts to do this.
//----------------------------------------------------------------------
class IRInterpreter
{
public:
    //------------------------------------------------------------------
    /// Constructor
    ///
    /// @param[in] decl_map
    ///     The list of externally-referenced variables for the expression,
    ///     for use in looking up globals and allocating the argument
    ///     struct.  See the documentation for ClangExpressionDeclMap.
    ///
    /// @param[in] error_stream
    ///     If non-NULL, a stream on which errors can be printed.
    //------------------------------------------------------------------
    IRInterpreter(lldb_private::ClangExpressionDeclMap &decl_map,
                  lldb_private::Stream *error_stream);
    
    //------------------------------------------------------------------
    /// Destructor
    //------------------------------------------------------------------
    ~IRInterpreter();
    
    //------------------------------------------------------------------
    /// Run the IR interpreter on a single function
    ///
    /// @param[in] result
    ///     This variable is populated with the return value of the
    ///     function, if it could be interpreted completely.
    ///
    /// @param[in] result_name
    ///     The name of the result in the IR.  If this name got a
    ///     value written to it as part of execution, then that value
    ///     will be used to create the result variable.
    ///
    /// @param[in] result_type
    ///     The type of the result.
    ///
    /// @param[in] llvm_function
    ///     The function to interpret.
    ///
    /// @param[in] llvm_module
    ///     The module containing the function.
    ///
    /// @param[in] error
    ///     If the expression fails to interpret, a reason why.
    ///
    /// @return
    ///     True on success; false otherwise
    //------------------------------------------------------------------
    bool 
    maybeRunOnFunction (lldb::ClangExpressionVariableSP &result,
                        const lldb_private::ConstString &result_name,
                        lldb_private::TypeFromParser result_type,
                        llvm::Function &llvm_function,
                        llvm::Module &llvm_module,
                        lldb_private::Error &err);
private:
    /// Flags
    lldb_private::ClangExpressionDeclMap &m_decl_map;       ///< The DeclMap containing the Decls 
    lldb_private::Stream *m_error_stream;
    
    bool
    supportsFunction (llvm::Function &llvm_function,
                      lldb_private::Error &err);
    
    bool 
    runOnFunction (lldb::ClangExpressionVariableSP &result,
                   const lldb_private::ConstString &result_name,
                   lldb_private::TypeFromParser result_type,
                   llvm::Function &llvm_function,
                   llvm::Module &llvm_module,
                   lldb_private::Error &err);
};

#endif