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 /* 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 (struct objfile *objfile)
  76     : objfile (objfile)
  77   {}
  78
  79   ~jiter_objfile_data ();
  80
  81   /* Back-link to the objfile. */
  82   struct objfile *objfile;
  83
  84   /* Symbol for __jit_debug_register_code.  */
  85   minimal_symbol *register_code = nullptr;
  86
  87   /* Symbol for __jit_debug_descriptor.  */
  88   minimal_symbol *descriptor = nullptr;
  89
  90   /* This is the relocated address of the __jit_debug_register_code function
  91      provided by this objfile.  This is used to detect relocations changes
  92      requiring the breakpoint to be re-created.  */
  93   CORE_ADDR cached_code_address = 0;
  94
  95   /* This is the JIT event breakpoint, or nullptr if it has been deleted.  */
  96   breakpoint *jit_breakpoint = nullptr;
  97 };
  98
  99 /* An objfile that is the product of JIT compilation and was registered
 100    using the JIT interface has an instance of this type attached to it.  */
 101
 102 struct jited_objfile_data
 103 {
 104   jited_objfile_data (CORE_ADDR addr)
 105     : addr (addr)
 106   {}
 107
 108   /* Address of struct jit_code_entry for this objfile.  */
 109   CORE_ADDR addr;
 110 };
 111
 112 /* Looks for the descriptor and registration symbols and breakpoints
 113    the registration function.  If it finds both, it registers all the
 114    already JITed code.  If it has already found the symbols, then it
 115    doesn't try again.  */
 116
 117 extern void jit_inferior_created_hook (void);
 118
 119 /* Re-establish the jit breakpoint(s).  */
 120
 121 extern void jit_breakpoint_re_set (void);
 122
 123 /* This function is called by handle_inferior_event when it decides
 124    that the JIT event breakpoint has fired.  JITER is the objfile
 125    whose JIT event breakpoint has been hit.  */
 126
 127 extern void jit_event_handler (gdbarch *gdbarch, objfile *jiter);
 128
 129 #endif /* JIT_H */