1//===-- UtilityFunction.h ----------------------------------------*- C++
2//-*-===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LLDB_EXPRESSION_UTILITYFUNCTION_H
11#define LLDB_EXPRESSION_UTILITYFUNCTION_H
12
13#include <memory>
14#include <string>
15
16#include "lldb/Expression/Expression.h"
17#include "lldb/lldb-forward.h"
18#include "lldb/lldb-private.h"
19
20namespace lldb_private {
21
22/// \class UtilityFunction UtilityFunction.h
23/// "lldb/Expression/UtilityFunction.h" Encapsulates a bit of source code that
24/// provides a function that is callable
25///
26/// LLDB uses expressions for various purposes, notably to call functions
27/// and as a backend for the expr command. UtilityFunction encapsulates a
28/// self-contained function meant to be used from other code. Utility
29/// functions can perform error-checking for ClangUserExpressions,
30class UtilityFunction : public Expression {
31 // LLVM RTTI support
32 static char ID;
33
34public:
35 bool isA(const void *ClassID) const override { return ClassID == &ID; }
36 static bool classof(const Expression *obj) { return obj->isA(ClassID: &ID); }
37
38 /// Constructor
39 ///
40 /// \param[in] text
41 /// The text of the function. Must be a full translation unit.
42 ///
43 /// \param[in] name
44 /// The name of the function, as used in the text.
45 ///
46 /// \param[in] enable_debugging
47 /// Enable debugging of this function.
48 UtilityFunction(ExecutionContextScope &exe_scope, std::string text,
49 std::string name, bool enable_debugging);
50
51 ~UtilityFunction() override;
52
53 /// Install the utility function into a process
54 ///
55 /// \param[in] diagnostic_manager
56 /// A diagnostic manager to print parse errors and warnings to.
57 ///
58 /// \param[in] exe_ctx
59 /// The execution context to install the utility function to.
60 ///
61 /// \return
62 /// True on success (no errors); false otherwise.
63 virtual bool Install(DiagnosticManager &diagnostic_manager,
64 ExecutionContext &exe_ctx) = 0;
65
66 /// Check whether the given address is inside the function
67 ///
68 /// Especially useful if the function dereferences nullptr to indicate a
69 /// failed assert.
70 ///
71 /// \param[in] address
72 /// The address to check.
73 ///
74 /// \return
75 /// True if the address falls within the function's bounds;
76 /// false if not (or the function is not JIT compiled)
77 bool ContainsAddress(lldb::addr_t address) {
78 // nothing is both >= LLDB_INVALID_ADDRESS and < LLDB_INVALID_ADDRESS, so
79 // this always returns false if the function is not JIT compiled yet
80 return (address >= m_jit_start_addr && address < m_jit_end_addr);
81 }
82
83 /// Return the string that the parser should parse. Must be a full
84 /// translation unit.
85 const char *Text() override { return m_function_text.c_str(); }
86
87 /// Return the function name that should be used for executing the
88 /// expression. Text() should contain the definition of this function.
89 const char *FunctionName() override { return m_function_name.c_str(); }
90
91 /// Return the object that the parser should use when registering local
92 /// variables. May be nullptr if the Expression doesn't care.
93 ExpressionVariableList *LocalVariables() { return nullptr; }
94
95 /// Return true if validation code should be inserted into the expression.
96 bool NeedsValidation() override { return false; }
97
98 /// Return true if external variables in the expression should be resolved.
99 bool NeedsVariableResolution() override { return false; }
100
101 // This makes the function caller function. Pass in the ThreadSP if you have
102 // one available, compilation can end up calling code (e.g. to look up
103 // indirect functions) and we don't want this to wander onto another thread.
104 FunctionCaller *MakeFunctionCaller(const CompilerType &return_type,
105 const ValueList &arg_value_list,
106 lldb::ThreadSP compilation_thread,
107 Status &error);
108
109 // This one retrieves the function caller that is already made. If you
110 // haven't made it yet, this returns nullptr
111 FunctionCaller *GetFunctionCaller() { return m_caller_up.get(); }
112
113protected:
114 std::shared_ptr<IRExecutionUnit> m_execution_unit_sp;
115 lldb::ModuleWP m_jit_module_wp;
116 /// The text of the function. Must be a well-formed translation unit.
117 std::string m_function_text;
118 /// The name of the function.
119 std::string m_function_name;
120 std::unique_ptr<FunctionCaller> m_caller_up;
121};
122
123} // namespace lldb_private
124
125#endif // LLDB_EXPRESSION_UTILITYFUNCTION_H
126

source code of lldb/include/lldb/Expression/UtilityFunction.h