xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/jit.h (revision cb63e24e8d6aae7ddac1859a9015f48b1d8bd90e)
1 /* JIT declarations for GDB, the GNU Debugger.
2 
3    Copyright (C) 2009-2020 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 #ifndef JIT_H
21 #define JIT_H
22 
23 struct objfile;
24 struct minimal_symbol;
25 
26 /* When the JIT breakpoint fires, the inferior wants us to take one of
27    these actions.  These values are used by the inferior, so the
28    values of these enums cannot be changed.  */
29 
30 typedef enum
31 {
32   JIT_NOACTION = 0,
33   JIT_REGISTER,
34   JIT_UNREGISTER
35 } jit_actions_t;
36 
37 /* This struct describes a single symbol file in a linked list of
38    symbol files describing generated code.  As the inferior generates
39    code, it adds these entries to the list, and when we attach to the
40    inferior, we read them all.  For the first element prev_entry
41    should be NULL, and for the last element next_entry should be
42    NULL.  */
43 
44 struct jit_code_entry
45 {
46   CORE_ADDR next_entry;
47   CORE_ADDR prev_entry;
48   CORE_ADDR symfile_addr;
49   ULONGEST symfile_size;
50 };
51 
52 /* This is the global descriptor that the inferior uses to communicate
53    information to the debugger.  To alert the debugger to take an
54    action, the inferior sets the action_flag to the appropriate enum
55    value, updates relevant_entry to point to the relevant code entry,
56    and calls the function at the well-known symbol with our
57    breakpoint.  We then read this descriptor from another global
58    well-known symbol.  */
59 
60 struct jit_descriptor
61 {
62   uint32_t version;
63   /* This should be jit_actions_t, but we want to be specific about the
64      bit-width.  */
65   uint32_t action_flag;
66   CORE_ADDR relevant_entry;
67   CORE_ADDR first_entry;
68 };
69 
70 /* An objfile that defines the required symbols of the JIT interface has an
71    instance of this type attached to it.  */
72 
73 struct jiter_objfile_data
74 {
75   ~jiter_objfile_data ();
76 
77   /* Symbol for __jit_debug_register_code.  */
78   minimal_symbol *register_code = nullptr;
79 
80   /* Symbol for __jit_debug_descriptor.  */
81   minimal_symbol *descriptor = nullptr;
82 
83   /* This is the relocated address of the __jit_debug_register_code function
84      provided by this objfile.  This is used to detect relocations changes
85      requiring the breakpoint to be re-created.  */
86   CORE_ADDR cached_code_address = 0;
87 
88   /* This is the JIT event breakpoint, or nullptr if it has been deleted.  */
89   breakpoint *jit_breakpoint = nullptr;
90 };
91 
92 /* An objfile that is the product of JIT compilation and was registered
93    using the JIT interface has an instance of this type attached to it.  */
94 
95 struct jited_objfile_data
96 {
97   jited_objfile_data (CORE_ADDR addr)
98     : addr (addr)
99   {}
100 
101   /* Address of struct jit_code_entry for this objfile.  */
102   CORE_ADDR addr;
103 };
104 
105 /* Looks for the descriptor and registration symbols and breakpoints
106    the registration function.  If it finds both, it registers all the
107    already JITed code.  If it has already found the symbols, then it
108    doesn't try again.  */
109 
110 extern void jit_inferior_created_hook (void);
111 
112 /* Re-establish the jit breakpoint(s).  */
113 
114 extern void jit_breakpoint_re_set (void);
115 
116 /* This function is called by handle_inferior_event when it decides
117    that the JIT event breakpoint has fired.  JITER is the objfile
118    whose JIT event breakpoint has been hit.  */
119 
120 extern void jit_event_handler (gdbarch *gdbarch, objfile *jiter);
121 
122 #endif /* JIT_H */
123