1 //===-- IRDynamicChecks.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_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_IRDYNAMICCHECKS_H
10 #define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_IRDYNAMICCHECKS_H
11 
12 #include "lldb/Expression/DynamicCheckerFunctions.h"
13 #include "lldb/lldb-types.h"
14 #include "llvm/Pass.h"
15 
16 namespace llvm {
17 class BasicBlock;
18 class Module;
19 }
20 
21 namespace lldb_private {
22 
23 class ExecutionContext;
24 class Stream;
25 
26 class ClangDynamicCheckerFunctions
27     : public lldb_private::DynamicCheckerFunctions {
28 public:
29   /// Constructor
30   ClangDynamicCheckerFunctions();
31 
32   /// Destructor
33   virtual ~ClangDynamicCheckerFunctions();
34 
35   static bool classof(const DynamicCheckerFunctions *checker_funcs) {
36     return checker_funcs->GetKind() == DCF_Clang;
37   }
38 
39   /// Install the utility functions into a process.  This binds the instance
40   /// of DynamicCheckerFunctions to that process.
41   ///
42   /// \param[in] diagnostic_manager
43   ///     A diagnostic manager to report errors to.
44   ///
45   /// \param[in] exe_ctx
46   ///     The execution context to install the functions into.
47   ///
48   /// \return
49   ///     True on success; false on failure, or if the functions have
50   ///     already been installed.
51   bool Install(DiagnosticManager &diagnostic_manager,
52                ExecutionContext &exe_ctx) override;
53 
54   bool DoCheckersExplainStop(lldb::addr_t addr, Stream &message) override;
55 
56   std::shared_ptr<UtilityFunction> m_valid_pointer_check;
57   std::shared_ptr<UtilityFunction> m_objc_object_check;
58 };
59 
60 /// \class IRDynamicChecks IRDynamicChecks.h
61 /// "lldb/Expression/IRDynamicChecks.h" Adds dynamic checks to a user-entered
62 /// expression to reduce its likelihood of crashing
63 ///
64 /// When an IR function is executed in the target process, it may cause
65 /// crashes or hangs by dereferencing NULL pointers, trying to call
66 /// Objective-C methods on objects that do not respond to them, and so forth.
67 ///
68 /// IRDynamicChecks adds calls to the functions in DynamicCheckerFunctions to
69 /// appropriate locations in an expression's IR.
70 class IRDynamicChecks : public llvm::ModulePass {
71 public:
72   /// Constructor
73   ///
74   /// \param[in] checker_functions
75   ///     The checker functions for the target process.
76   ///
77   /// \param[in] func_name
78   ///     The name of the function to prepare for execution in the target.
79   IRDynamicChecks(ClangDynamicCheckerFunctions &checker_functions,
80                   const char *func_name = "$__lldb_expr");
81 
82   /// Destructor
83   ~IRDynamicChecks() override;
84 
85   /// Run this IR transformer on a single module
86   ///
87   /// \param[in] M
88   ///     The module to run on.  This module is searched for the function
89   ///     $__lldb_expr, and that function is passed to the passes one by
90   ///     one.
91   ///
92   /// \return
93   ///     True on success; false otherwise
94   bool runOnModule(llvm::Module &M) override;
95 
96   /// Interface stub
97   void assignPassManager(
98       llvm::PMStack &PMS,
99       llvm::PassManagerType T = llvm::PMT_ModulePassManager) override;
100 
101   /// Returns PMT_ModulePassManager
102   llvm::PassManagerType getPotentialPassManagerType() const override;
103 
104 private:
105   /// A basic block-level pass to find all pointer dereferences and
106   /// validate them before use.
107 
108   /// The top-level pass implementation
109   ///
110   /// \param[in] M
111   ///     The module currently being processed.
112   ///
113   /// \param[in] BB
114   ///     The basic block currently being processed.
115   ///
116   /// \return
117   ///     True on success; false otherwise
118   bool FindDataLoads(llvm::Module &M, llvm::BasicBlock &BB);
119 
120   std::string m_func_name; ///< The name of the function to add checks to
121   ClangDynamicCheckerFunctions
122       &m_checker_functions; ///< The checker functions for the process
123 };
124 
125 } // namespace lldb_private
126 
127 #endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_IRDYNAMICCHECKS_H
128