source/Plugins/ExpressionParser/Swift/SwiftUserExpression.h

//===-- SwiftUserExpression.h -----------------------------------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_SwiftUserExpression_h_
#define liblldb_SwiftUserExpression_h_

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

#include "lldb/Expression/LLVMUserExpression.h"
#include "lldb/Expression/Materializer.h"

// Other libraries and framework includes
// Project includes

namespace lldb_private {

//----------------------------------------------------------------------
/// @class SwiftUserExpression SwiftUserExpression.h
/// "lldb/Expression/SwiftUserExpression.h"
/// @brief Encapsulates a single expression for use with Clang
///
/// LLDB uses expressions for various purposes, notably to call functions
/// and as a backend for the expr command.  SwiftUserExpression encapsulates
/// the objects needed to parse and interpret or JIT an expression.  It
/// uses the Clang parser to produce LLVM IR from the expression.
//----------------------------------------------------------------------
class SwiftUserExpression : public LLVMUserExpression {
public:
  enum { kDefaultTimeout = 500000u };

  enum {
    eLanguageFlagNeedsObjectPointer = 1 << 0,
    eLanguageFlagInStaticMethod = 1 << 1,
    eLanguageFlagIsClass = 1 << 2,
    eLanguageFlagIsWeakSelf = 1 << 3
  };

  class SwiftUserExpressionHelper : public ExpressionTypeSystemHelper {
  public:
    SwiftUserExpressionHelper(Target &target)
        : ExpressionTypeSystemHelper(eKindSwiftHelper), m_target(target) {}

    ~SwiftUserExpressionHelper() {}

  private:
    Target &m_target;
  };

  //------------------------------------------------------------------
  /// Constructor
  ///
  /// @param[in] expr
  ///     The expression to parse.
  ///
  /// @param[in] expr_prefix
  ///     If non-NULL, a C string containing translation-unit level
  ///     definitions to be included when the expression is parsed.
  ///
  /// @param[in] language
  ///     If not eLanguageTypeUnknown, a language to use when parsing
  ///     the expression.  Currently restricted to those languages
  ///     supported by Clang.
  ///
  /// @param[in] desired_type
  ///     If not eResultTypeAny, the type to use for the expression
  ///     result.
  ///
  /// @param[in] options
  ///     Additional options for the expression.
  //------------------------------------------------------------------
  SwiftUserExpression(ExecutionContextScope &exe_scope, llvm::StringRef expr,
                      llvm::StringRef prefix, lldb::LanguageType language,
                      ResultType desired_type,
                      const EvaluateExpressionOptions &options);

  //------------------------------------------------------------------
  /// Destructor
  //------------------------------------------------------------------
  ~SwiftUserExpression() override;

  //------------------------------------------------------------------
  /// Parse the expression
  ///
  /// @param[in] diagnostic_manager
  ///     A diagnostic manager to report parse errors and warnings to.
  ///
  /// @param[in] exe_ctx
  ///     The execution context to use when looking up entities that
  ///     are needed for parsing (locations of functions, types of
  ///     variables, persistent variables, etc.)
  ///
  /// @param[in] execution_policy
  ///     Determines whether interpretation is possible or mandatory.
  ///
  /// @param[in] keep_result_in_memory
  ///     True if the resulting persistent variable should reside in
  ///     target memory, if applicable.
  ///
  /// @return
  ///     True on success (no errors); false otherwise.
  //------------------------------------------------------------------
  bool Parse(DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
             lldb_private::ExecutionPolicy execution_policy,
             bool keep_result_in_memory, bool generate_debug_info,
             uint32_t line_offset = 0) override;

  ExpressionTypeSystemHelper *GetTypeSystemHelper() override {
    return &m_type_system_helper;
  }

  Materializer::PersistentVariableDelegate &GetResultDelegate() {
    return m_result_delegate;
  }

  Materializer::PersistentVariableDelegate &GetErrorDelegate() {
    return m_error_delegate;
  }

  Materializer::PersistentVariableDelegate &GetPersistentVariableDelegate() {
    return m_persistent_variable_delegate;
  }

  lldb::ExpressionVariableSP
  GetResultAfterDematerialization(ExecutionContextScope *exe_scope) override;

  void WillStartExecuting() override;
  void DidFinishExecuting() override;

private:
  //------------------------------------------------------------------
  /// Populate m_in_cplusplus_method and m_in_objectivec_method based on the
  /// environment.
  //------------------------------------------------------------------

  void ScanContext(ExecutionContext &exe_ctx,
                   lldb_private::Status &err) override;

  bool AddArguments(ExecutionContext &exe_ctx, std::vector<lldb::addr_t> &args,
                    lldb::addr_t struct_address,
                    DiagnosticManager &diagnostic_manager) override;

  SwiftUserExpressionHelper m_type_system_helper;

  class ResultDelegate : public Materializer::PersistentVariableDelegate {
  public:
    ResultDelegate(SwiftUserExpression &, bool is_error);
    ConstString GetName() override;
    void DidDematerialize(lldb::ExpressionVariableSP &variable) override;

    void RegisterPersistentState(PersistentExpressionState *persistent_state);
    lldb::ExpressionVariableSP &GetVariable();

  private:
    SwiftUserExpression &m_user_expression;
    bool m_is_error;
    PersistentExpressionState *m_persistent_state;
    lldb::ExpressionVariableSP m_variable;
  };

  ResultDelegate m_result_delegate;
  ResultDelegate m_error_delegate;

  class PersistentVariableDelegate
      : public Materializer::PersistentVariableDelegate {
  public:
    PersistentVariableDelegate(SwiftUserExpression &);
    ConstString GetName() override;
    void DidDematerialize(lldb::ExpressionVariableSP &variable) override;

  private:
    SwiftUserExpression &m_user_expression;
  };

  PersistentVariableDelegate m_persistent_variable_delegate;
};

} // namespace lldb_private

#endif // liblldb_SwiftUserExpression_h_