gdb/jit.h

   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 /* Per-objfile structure recording the addresses in the program space.
  71    This object serves two purposes: for ordinary objfiles, it may
  72    cache some symbols related to the JIT interface; and for
  73    JIT-created objfiles, it holds some information about the
  74    jit_code_entry.  */
  75
  76 struct jit_objfile_data
  77 {
  78   jit_objfile_data (struct objfile *objfile)
  79     : objfile (objfile)
  80   {}
  81
  82   ~jit_objfile_data ();
  83
  84   /* Back-link to the objfile. */
  85   struct objfile *objfile;
  86
  87   /* Symbol for __jit_debug_register_code.  */
  88   minimal_symbol *register_code = nullptr;
  89
  90   /* Symbol for __jit_debug_descriptor.  */
  91   minimal_symbol *descriptor = nullptr;
  92
  93   /* Address of struct jit_code_entry in this objfile.  This is only
  94      non-zero for objfiles that represent code created by the JIT.  */
  95   CORE_ADDR addr = 0;
  96 };
  97
  98 /* Looks for the descriptor and registration symbols and breakpoints
  99    the registration function.  If it finds both, it registers all the
 100    already JITed code.  If it has already found the symbols, then it
 101    doesn't try again.  */
 102
 103 extern void jit_inferior_created_hook (void);
 104
 105 /* Re-establish the jit breakpoint(s).  */
 106
 107 extern void jit_breakpoint_re_set (void);
 108
 109 /* This function is called by handle_inferior_event when it decides
 110    that the JIT event breakpoint has fired.  JITER is the objfile
 111    whose JIT event breakpoint has been hit.  */
 112
 113 extern void jit_event_handler (gdbarch *gdbarch, objfile *jiter);
 114
 115 #endif /* JIT_H */