ClangExpressionVariable.h revision 4a7c6c62ac427ac3a390809a6ab1fe325cc69a0e 
1//===-- ClangExpressionVariable.h -------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef liblldb_ClangExpressionVariable_h_
11#define liblldb_ClangExpressionVariable_h_
12
13// C Includes
14#include <signal.h>
15#include <stdint.h>
16
17// C++ Includes
18#include <vector>
19
20// Other libraries and framework includes
21// Project includes
22#include "lldb/Core/ClangForward.h"
23#include "lldb/Core/Value.h"
24
25namespace lldb_private {
26
27//----------------------------------------------------------------------
28/// @class ClangExpressionVariableList ClangExpressionVariable.h "lldb/Expression/ClangExpressionVariable.h"
29/// @brief Manages local variables that the expression interpreter uses.
30///
31/// The DWARF interpreter, when interpreting expressions, occasionally
32/// needs to interact with chunks of memory corresponding to local variable
33/// values.  These locals are distinct from the externally-defined values
34/// handled by ClangExpressionDeclMap, and do not persist between expressions
35/// so they are not handled by ClangPersistentVariables.  They are kept in a
36/// list, which is encapsulated in ClangEpxressionVariableList.
37//----------------------------------------------------------------------
38class ClangExpressionVariableList
39{
40public:
41    //----------------------------------------------------------------------
42    /// Constructor
43    //----------------------------------------------------------------------
44    ClangExpressionVariableList();
45
46    //----------------------------------------------------------------------
47    /// Destructor
48    //----------------------------------------------------------------------
49    ~ClangExpressionVariableList();
50
51    //----------------------------------------------------------------------
52    /// Get or create the chunk of data corresponding to a given VarDecl.
53    ///
54    /// @param[in] var_decl
55    ///     The Decl for which a chunk of memory is to be allocated.
56    ///
57    /// @param[out] idx
58    ///     The index of the Decl in the list of variables.
59    ///
60    /// @param[in] can_create
61    ///     True if the memory should be created if necessary.
62    ///
63    /// @return
64    ///     A Value for the allocated memory.  NULL if the Decl couldn't be
65    ///     found and can_create was false, or if some error occurred during
66    ///     allocation.
67    //----------------------------------------------------------------------
68    Value *
69    GetVariableForVarDecl (const clang::VarDecl *var_decl,
70                           uint32_t& idx,
71                           bool can_create);
72
73    //----------------------------------------------------------------------
74    /// Get the chunk of data corresponding to a given index into the list.
75    ///
76    /// @param[in] idx
77    ///     The index of the Decl in the list of variables.
78    ///
79    /// @return
80    ///     The value at the given index, or NULL if there is none.
81    //----------------------------------------------------------------------
82    Value *
83    GetVariableAtIndex (uint32_t idx);
84private:
85    //----------------------------------------------------------------------
86    /// @class ClangExpressionVariable ClangExpressionVariable.h "lldb/Expression/ClangExpressionVariable.h"
87    /// @brief Manages one local variable for the expression interpreter.
88    ///
89    /// The expression interpreter uses specially-created Values to hold its
90    /// temporary locals.  These Values contain data buffers holding enough
91    /// space to contain a variable of the appropriate type.  The VarDecls
92    /// are only used while creating the list and generating the DWARF code for
93    /// an expression; when interpreting the DWARF, the variables are identified
94    /// only by their index into the list of variables.
95    //----------------------------------------------------------------------
96    struct ClangExpressionVariable
97    {
98        const clang::VarDecl    *m_var_decl;    ///< The VarDecl corresponding to the parsed local.
99        Value                   *m_value;       ///< The LLDB Value containing the data for the local.
100    };
101
102    typedef std::vector<ClangExpressionVariable> Variables;
103    Variables m_variables;                                  ///< The list of variables used by the expression.
104};
105
106} // namespace lldb_private
107
108#endif  // liblldb_ClangExpressionVariable_h_
109