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ClangExpressionVariable.h
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1 //===-- ClangExpressionVariable.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_CLANGEXPRESSIONVARIABLE_H
10 #define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONVARIABLE_H
11 
12 #include <signal.h>
13 #include <stdint.h>
14 #include <string.h>
15 
16 #include <map>
17 #include <string>
18 #include <vector>
19 
20 #include "llvm/Support/Casting.h"
21 
22 #include "lldb/Core/Value.h"
26 #include "lldb/lldb-public.h"
27 
28 namespace llvm {
29 class Value;
30 }
31 
32 namespace clang {
33 class NamedDecl;
34 }
35 
36 namespace lldb_private {
37 
38 class ValueObjectConstResult;
39 
40 /// \class ClangExpressionVariable ClangExpressionVariable.h
41 /// "lldb/Expression/ClangExpressionVariable.h" Encapsulates one variable for
42 /// the expression parser.
43 ///
44 /// The expression parser uses variables in three different contexts:
45 ///
46 /// First, it stores persistent variables along with the process for use in
47 /// expressions. These persistent variables contain their own data and are
48 /// typed.
49 ///
50 /// Second, in an interpreted expression, it stores the local variables for
51 /// the expression along with the expression. These variables contain their
52 /// own data and are typed.
53 ///
54 /// Third, in a JIT-compiled expression, it stores the variables that the
55 /// expression needs to have materialized and dematerialized at each
56 /// execution. These do not contain their own data but are named and typed.
57 ///
58 /// This class supports all of these use cases using simple type polymorphism,
59 /// and provides necessary support methods. Its interface is RTTI-neutral.
61 public:
63  lldb::ByteOrder byte_order, uint32_t addr_byte_size);
64 
66  ConstString name, uint16_t flags = EVNone);
67 
68  ClangExpressionVariable(const lldb::ValueObjectSP &valobj_sp);
69 
71  ConstString name,
72  const TypeFromUser &user_type,
73  lldb::ByteOrder byte_order, uint32_t addr_byte_size);
74 
75  /// Utility functions for dealing with ExpressionVariableLists in Clang-
76  /// specific ways
77 
78  /// Finds a variable by NamedDecl in the list.
79  ///
80  /// \return
81  /// The variable requested, or NULL if that variable is not in the list.
83  FindVariableInList(ExpressionVariableList &list, const clang::NamedDecl *decl,
84  uint64_t parser_id) {
85  lldb::ExpressionVariableSP var_sp;
86  for (size_t index = 0, size = list.GetSize(); index < size; ++index) {
87  var_sp = list.GetVariableAtIndex(index);
88 
89  if (ClangExpressionVariable *clang_var =
90  llvm::dyn_cast<ClangExpressionVariable>(var_sp.get())) {
92  clang_var->GetParserVars(parser_id);
93 
94  if (parser_vars && parser_vars->m_named_decl == decl)
95  return clang_var;
96  }
97  }
98  return nullptr;
99  }
100 
101  /// If the variable contains its own data, make a Value point at it. If \a
102  /// exe_ctx in not NULL, the value will be resolved in with that execution
103  /// context.
104  ///
105  /// \param[in] value
106  /// The value to point at the data.
107  ///
108  /// \param[in] exe_ctx
109  /// The execution context to use to resolve \a value.
110  ///
111  /// \return
112  /// True on success; false otherwise (in particular, if this variable
113  /// does not contain its own data).
114  bool PointValueAtData(Value &value, ExecutionContext *exe_ctx);
115 
116  /// The following values should not live beyond parsing
117  class ParserVars {
118  public:
120  : m_named_decl(nullptr), m_llvm_value(nullptr),
121  m_lldb_value(), m_lldb_var(), m_lldb_sym(nullptr) {}
122 
123  const clang::NamedDecl
124  *m_named_decl; ///< The Decl corresponding to this variable
125  llvm::Value *m_llvm_value; ///< The IR value corresponding to this variable;
126  ///usually a GlobalValue
128  m_lldb_value; ///< The value found in LLDB for this variable
129  lldb::VariableSP m_lldb_var; ///< The original variable for this variable
130  const lldb_private::Symbol *m_lldb_sym; ///< The original symbol for this
131  ///variable, if it was a symbol
132  };
133 
134 private:
135  typedef std::map<uint64_t, ParserVars> ParserVarMap;
136  ParserVarMap m_parser_vars;
137 
138 public:
139  /// Make this variable usable by the parser by allocating space for parser-
140  /// specific variables
141  void EnableParserVars(uint64_t parser_id) {
142  m_parser_vars.insert(std::make_pair(parser_id, ParserVars()));
143  }
144 
145  /// Deallocate parser-specific variables
146  void DisableParserVars(uint64_t parser_id) { m_parser_vars.erase(parser_id); }
147 
148  /// Access parser-specific variables
149  ParserVars *GetParserVars(uint64_t parser_id) {
150  ParserVarMap::iterator i = m_parser_vars.find(parser_id);
151 
152  if (i == m_parser_vars.end())
153  return nullptr;
154  else
155  return &i->second;
156  }
157 
158  /// The following values are valid if the variable is used by JIT code
159  struct JITVars {
160  JITVars() : m_alignment(0), m_size(0), m_offset(0) {}
161 
163  m_alignment; ///< The required alignment of the variable, in bytes
164  size_t m_size; ///< The space required for the variable, in bytes
166  m_offset; ///< The offset of the variable in the struct, in bytes
167  };
168 
169 private:
170  typedef std::map<uint64_t, JITVars> JITVarMap;
171  JITVarMap m_jit_vars;
172 
173 public:
174  /// Make this variable usable for materializing for the JIT by allocating
175  /// space for JIT-specific variables
176  void EnableJITVars(uint64_t parser_id) {
177  m_jit_vars.insert(std::make_pair(parser_id, JITVars()));
178  }
179 
180  /// Deallocate JIT-specific variables
181  void DisableJITVars(uint64_t parser_id) { m_jit_vars.erase(parser_id); }
182 
183  JITVars *GetJITVars(uint64_t parser_id) {
184  JITVarMap::iterator i = m_jit_vars.find(parser_id);
185 
186  if (i == m_jit_vars.end())
187  return nullptr;
188  else
189  return &i->second;
190  }
191 
192  TypeFromUser GetTypeFromUser();
193 
194  // llvm casting support
195  static bool classof(const ExpressionVariable *ev) {
196  return ev->getKind() == ExpressionVariable::eKindClang;
197  }
198 
199  /// Members
202  operator=(const ClangExpressionVariable &) = delete;
203 };
204 
205 } // namespace lldb_private
206 
207 #endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONVARIABLE_H
lldb::offset_t m_alignment
The required alignment of the variable, in bytes.
A class that represents a running process on the host machine.
Definition: Debugger.h:49
static ClangExpressionVariable * FindVariableInList(ExpressionVariableList &list, const clang::NamedDecl *decl, uint64_t parser_id)
Utility functions for dealing with ExpressionVariableLists in Clang- specific ways.
void DisableParserVars(uint64_t parser_id)
Deallocate parser-specific variables.
lldb::VariableSP m_lldb_var
The original variable for this variable.
"lldb/Target/ExecutionContext.h" A class that contains an execution context.
ParserVars * GetParserVars(uint64_t parser_id)
Access parser-specific variables.
JITVars * GetJITVars(uint64_t parser_id)
lldb_private::Value m_lldb_value
The value found in LLDB for this variable.
static bool classof(const ExpressionVariable *ev)
const lldb_private::Symbol * m_lldb_sym
The original symbol for this variable, if it was a symbol.
void EnableJITVars(uint64_t parser_id)
Make this variable usable for materializing for the JIT by allocating space for JIT-specific variable...
uint64_t offset_t
Definition: lldb-types.h:87
"lldb/Expression/ExpressionVariable.h" A list of variable references.
ByteOrder
Byte ordering definitions.
"lldb/Target/ExecutionContextScope.h" Inherit from this if your object can reconstruct its execution ...
lldb::offset_t m_offset
The offset of the variable in the struct, in bytes.
The following values should not live beyond parsing.
lldb::ExpressionVariableSP GetVariableAtIndex(size_t index)
The following values are valid if the variable is used by JIT code.
size_t GetSize()
Implementation of methods in ExpressionVariableListBase.
void EnableParserVars(uint64_t parser_id)
Make this variable usable by the parser by allocating space for parser- specific variables.
llvm::Value * m_llvm_value
The IR value corresponding to this variable; usually a GlobalValue.
A uniqued constant string class.
Definition: ConstString.h:40
const clang::NamedDecl * m_named_decl
The Decl corresponding to this variable.
std::map< uint64_t, ParserVars > ParserVarMap
void DisableJITVars(uint64_t parser_id)
Deallocate JIT-specific variables.
size_t m_size
The space required for the variable, in bytes.
"lldb/Expression/ClangExpressionVariable.h" Encapsulates one variable for the expression parser...