1//===-- Expression.h --------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLDB_EXPRESSION_EXPRESSION_H
10#define LLDB_EXPRESSION_EXPRESSION_H
11
12#include <map>
13#include <string>
14#include <vector>
15
16
17#include "lldb/Expression/ExpressionTypeSystemHelper.h"
18#include "lldb/lldb-forward.h"
19#include "lldb/lldb-private.h"
20
21namespace lldb_private {
22
23/// \class Expression Expression.h "lldb/Expression/Expression.h" Encapsulates
24/// a single expression for use in lldb
25///
26/// LLDB uses expressions for various purposes, notably to call functions
27/// and as a backend for the expr command.  Expression encapsulates the
28/// objects needed to parse and interpret or JIT an expression.  It uses the
29/// expression parser appropriate to the language of the expression to produce
30/// LLVM IR from the expression.
31class Expression {
32public:
33  enum ResultType { eResultTypeAny, eResultTypeId };
34
35  Expression(Target &target);
36
37  Expression(ExecutionContextScope &exe_scope);
38
39  /// Destructor
40  virtual ~Expression() = default;
41
42  /// Return the string that the parser should parse.  Must be a full
43  /// translation unit.
44  virtual const char *Text() = 0;
45
46  /// Return the function name that should be used for executing the
47  /// expression.  Text() should contain the definition of this function.
48  virtual const char *FunctionName() = 0;
49
50  /// Return the language that should be used when parsing.  To use the
51  /// default, return eLanguageTypeUnknown.
52  virtual lldb::LanguageType Language() const {
53    return lldb::eLanguageTypeUnknown;
54  }
55
56  /// Return the Materializer that the parser should use when registering
57  /// external values.
58  virtual Materializer *GetMaterializer() { return nullptr; }
59
60  /// Return the desired result type of the function, or eResultTypeAny if
61  /// indifferent.
62  virtual ResultType DesiredResultType() { return eResultTypeAny; }
63
64  /// Flags
65
66  /// Return true if validation code should be inserted into the expression.
67  virtual bool NeedsValidation() = 0;
68
69  /// Return true if external variables in the expression should be resolved.
70  virtual bool NeedsVariableResolution() = 0;
71
72  virtual EvaluateExpressionOptions *GetOptions() { return nullptr; };
73
74  /// Return the address of the function's JIT-compiled code, or
75  /// LLDB_INVALID_ADDRESS if the function is not JIT compiled
76  lldb::addr_t StartAddress() { return m_jit_start_addr; }
77
78  /// Called to notify the expression that it is about to be executed.
79  virtual void WillStartExecuting() {}
80
81  /// Called to notify the expression that its execution has finished.
82  virtual void DidFinishExecuting() {}
83
84  virtual ExpressionTypeSystemHelper *GetTypeSystemHelper() { return nullptr; }
85
86  // LLVM RTTI support
87  virtual bool isA(const void *ClassID) const = 0;
88
89protected:
90  lldb::TargetWP m_target_wp; /// Expression's always have to have a target...
91  lldb::ProcessWP m_jit_process_wp; /// An expression might have a process, but
92                                    /// it doesn't need to (e.g. calculator
93                                    /// mode.)
94  lldb::addr_t m_jit_start_addr; ///< The address of the JITted function within
95                                 ///the JIT allocation.  LLDB_INVALID_ADDRESS if
96                                 ///invalid.
97  lldb::addr_t m_jit_end_addr;   ///< The address of the JITted function within
98                                 ///the JIT allocation.  LLDB_INVALID_ADDRESS if
99                                 ///invalid.
100};
101
102} // namespace lldb_private
103
104#endif // LLDB_EXPRESSION_EXPRESSION_H
105