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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 liblldb_ClangExpressionVariable_h_
10 #define liblldb_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/ClangForward.h"
23 #include "lldb/Core/Value.h"
27 #include "lldb/lldb-public.h"
28 
29 namespace llvm {
30 class Value;
31 }
32 
33 namespace lldb_private {
34 
35 class ValueObjectConstResult;
36 
37 /// \class ClangExpressionVariable ClangExpressionVariable.h
38 /// "lldb/Expression/ClangExpressionVariable.h" Encapsulates one variable for
39 /// the expression parser.
40 ///
41 /// The expression parser uses variables in three different contexts:
42 ///
43 /// First, it stores persistent variables along with the process for use in
44 /// expressions. These persistent variables contain their own data and are
45 /// typed.
46 ///
47 /// Second, in an interpreted expression, it stores the local variables for
48 /// the expression along with the expression. These variables contain their
49 /// own data and are typed.
50 ///
51 /// Third, in a JIT-compiled expression, it stores the variables that the
52 /// expression needs to have materialized and dematerialized at each
53 /// execution. These do not contain their own data but are named and typed.
54 ///
55 /// This class supports all of these use cases using simple type polymorphism,
56 /// and provides necessary support methods. Its interface is RTTI-neutral.
58 public:
60  lldb::ByteOrder byte_order, uint32_t addr_byte_size);
61 
63  ConstString name, uint16_t flags = EVNone);
64 
65  ClangExpressionVariable(const lldb::ValueObjectSP &valobj_sp);
66 
68  ConstString name,
69  const TypeFromUser &user_type,
70  lldb::ByteOrder byte_order, uint32_t addr_byte_size);
71 
72  /// Utility functions for dealing with ExpressionVariableLists in Clang-
73  /// specific ways
74 
75  /// Finds a variable by NamedDecl in the list.
76  ///
77  /// \param[in] name
78  /// The name of the requested variable.
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_parser_type(), m_named_decl(NULL), m_llvm_value(NULL),
121  m_lldb_value(), m_lldb_var(), m_lldb_sym(NULL) {}
122 
124  m_parser_type; ///< The type of the variable according to the parser
125  const clang::NamedDecl
126  *m_named_decl; ///< The Decl corresponding to this variable
127  llvm::Value *m_llvm_value; ///< The IR value corresponding to this variable;
128  ///usually a GlobalValue
130  m_lldb_value; ///< The value found in LLDB for this variable
131  lldb::VariableSP m_lldb_var; ///< The original variable for this variable
132  const lldb_private::Symbol *m_lldb_sym; ///< The original symbol for this
133  ///variable, if it was a symbol
134  };
135 
136 private:
137  typedef std::map<uint64_t, ParserVars> ParserVarMap;
138  ParserVarMap m_parser_vars;
139 
140 public:
141  /// Make this variable usable by the parser by allocating space for parser-
142  /// specific variables
143  void EnableParserVars(uint64_t parser_id) {
144  m_parser_vars.insert(std::make_pair(parser_id, ParserVars()));
145  }
146 
147  /// Deallocate parser-specific variables
148  void DisableParserVars(uint64_t parser_id) { m_parser_vars.erase(parser_id); }
149 
150  /// Access parser-specific variables
151  ParserVars *GetParserVars(uint64_t parser_id) {
152  ParserVarMap::iterator i = m_parser_vars.find(parser_id);
153 
154  if (i == m_parser_vars.end())
155  return NULL;
156  else
157  return &i->second;
158  }
159 
160  /// The following values are valid if the variable is used by JIT code
161  struct JITVars {
162  JITVars() : m_alignment(0), m_size(0), m_offset(0) {}
163 
165  m_alignment; ///< The required alignment of the variable, in bytes
166  size_t m_size; ///< The space required for the variable, in bytes
168  m_offset; ///< The offset of the variable in the struct, in bytes
169  };
170 
171 private:
172  typedef std::map<uint64_t, JITVars> JITVarMap;
173  JITVarMap m_jit_vars;
174 
175 public:
176  /// Make this variable usable for materializing for the JIT by allocating
177  /// space for JIT-specific variables
178  void EnableJITVars(uint64_t parser_id) {
179  m_jit_vars.insert(std::make_pair(parser_id, JITVars()));
180  }
181 
182  /// Deallocate JIT-specific variables
183  void DisableJITVars(uint64_t parser_id) { m_jit_vars.erase(parser_id); }
184 
185  JITVars *GetJITVars(uint64_t parser_id) {
186  JITVarMap::iterator i = m_jit_vars.find(parser_id);
187 
188  if (i == m_jit_vars.end())
189  return NULL;
190  else
191  return &i->second;
192  }
193 
194  TypeFromUser GetTypeFromUser();
195 
196  // llvm casting support
197  static bool classof(const ExpressionVariable *ev) {
198  return ev->getKind() == ExpressionVariable::eKindClang;
199  }
200 
201  /// Members
202  DISALLOW_COPY_AND_ASSIGN(ClangExpressionVariable);
203 };
204 
205 } // namespace lldb_private
206 
207 #endif // liblldb_ClangExpressionVariable_h_
lldb::offset_t m_alignment
The required alignment of the variable, in bytes.
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
Definition: Debugger.h:71
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...
TypeFromParser m_parser_type
The type of the variable according to the parser.
uint64_t offset_t
Definition: lldb-types.h:87
"lldb/Expression/ExpressionVariable.h" A list of variable references.
"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:38
const clang::NamedDecl * m_named_decl
The Decl corresponding to this variable.
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...