LLVMUserExpression.h revision 360784 
1//===-- LLVMUserExpression.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 liblldb_LLVMUserExpression_h
10#define liblldb_LLVMUserExpression_h
11
12#include <map>
13#include <string>
14#include <vector>
15
16#include "llvm/IR/LegacyPassManager.h"
17
18#include "lldb/Expression/UserExpression.h"
19
20namespace lldb_private {
21
22/// \class LLVMUserExpression LLVMUserExpression.h
23/// "lldb/Expression/LLVMUserExpression.h" Encapsulates a one-time expression
24/// 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.  LLVMUserExpression is a virtual
28/// base class that encapsulates the objects needed to parse and JIT an
29/// expression. The actual parsing part will be provided by the specific
30/// implementations of LLVMUserExpression - which will be vended through the
31/// appropriate TypeSystem.
32class LLVMUserExpression : public UserExpression {
33  // LLVM RTTI support
34  static char ID;
35
36public:
37  bool isA(const void *ClassID) const override {
38    return ClassID == &ID || UserExpression::isA(ClassID);
39  }
40  static bool classof(const Expression *obj) { return obj->isA(&ID); }
41
42  // The IRPasses struct is filled in by a runtime after an expression is
43  // compiled and can be used to to run fixups/analysis passes as required.
44  // EarlyPasses are run on the generated module before lldb runs its own IR
45  // fixups and inserts instrumentation code/pointer checks. LatePasses are run
46  // after the module has been processed by llvm, before the module is
47  // assembled and run in the ThreadPlan.
48  struct IRPasses {
49    IRPasses() : EarlyPasses(nullptr), LatePasses(nullptr){};
50    std::shared_ptr<llvm::legacy::PassManager> EarlyPasses;
51    std::shared_ptr<llvm::legacy::PassManager> LatePasses;
52  };
53
54  LLVMUserExpression(ExecutionContextScope &exe_scope, llvm::StringRef expr,
55                     llvm::StringRef prefix, lldb::LanguageType language,
56                     ResultType desired_type,
57                     const EvaluateExpressionOptions &options);
58  ~LLVMUserExpression() override;
59
60  bool FinalizeJITExecution(
61      DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
62      lldb::ExpressionVariableSP &result,
63      lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS,
64      lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS) override;
65
66  bool CanInterpret() override { return m_can_interpret; }
67
68  Materializer *GetMaterializer() override { return m_materializer_up.get(); }
69
70  /// Return the string that the parser should parse.  Must be a full
71  /// translation unit.
72  const char *Text() override { return m_transformed_text.c_str(); }
73
74  lldb::ModuleSP GetJITModule() override;
75
76protected:
77  lldb::ExpressionResults
78  DoExecute(DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
79            const EvaluateExpressionOptions &options,
80            lldb::UserExpressionSP &shared_ptr_to_me,
81            lldb::ExpressionVariableSP &result) override;
82
83  virtual void ScanContext(ExecutionContext &exe_ctx,
84                           lldb_private::Status &err) = 0;
85
86  bool PrepareToExecuteJITExpression(DiagnosticManager &diagnostic_manager,
87                                     ExecutionContext &exe_ctx,
88                                     lldb::addr_t &struct_address);
89
90  virtual bool AddArguments(ExecutionContext &exe_ctx,
91                            std::vector<lldb::addr_t> &args,
92                            lldb::addr_t struct_address,
93                            DiagnosticManager &diagnostic_manager) = 0;
94
95  lldb::addr_t
96      m_stack_frame_bottom;       ///< The bottom of the allocated stack frame.
97  lldb::addr_t m_stack_frame_top; ///< The top of the allocated stack frame.
98
99  bool m_allow_cxx;  ///< True if the language allows C++.
100  bool m_allow_objc; ///< True if the language allows Objective-C.
101  std::string
102      m_transformed_text; ///< The text of the expression, as send to the parser
103
104  std::shared_ptr<IRExecutionUnit>
105      m_execution_unit_sp; ///< The execution unit the expression is stored in.
106  std::unique_ptr<Materializer> m_materializer_up; ///< The materializer to use
107                                                   /// when running the
108                                                   /// expression.
109  lldb::ModuleWP m_jit_module_wp;
110  Target *m_target; ///< The target for storing persistent data like types and
111                    ///variables.
112
113  bool m_can_interpret; ///< True if the expression could be evaluated
114                        ///statically; false otherwise.
115  lldb::addr_t m_materialized_address; ///< The address at which the arguments
116                                       ///to the expression have been
117                                       ///materialized.
118  Materializer::DematerializerSP m_dematerializer_sp; ///< The dematerializer.
119};
120
121} // namespace lldb_private
122#endif
123