1 /* Handle JIT code generation in the inferior for GDB, the GNU Debugger.
3 Copyright (C) 2009-2022 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
23 #include "jit-reader.h"
25 #include "breakpoint.h"
27 #include "dictionary.h"
28 #include "filenames.h"
29 #include "frame-unwind.h"
33 #include "observable.h"
39 #include "gdbsupport/gdb-dlfcn.h"
42 #include "readline/tilde.h"
43 #include "completer.h"
44 #include <forward_list>
46 static std::string jit_reader_dir
;
48 static const char jit_break_name
[] = "__jit_debug_register_code";
50 static const char jit_descriptor_name
[] = "__jit_debug_descriptor";
52 static void jit_inferior_created_hook (inferior
*inf
);
53 static void jit_inferior_exit_hook (struct inferior
*inf
);
55 /* An unwinder is registered for every gdbarch. This key is used to
56 remember if the unwinder has been registered for a particular
59 static struct gdbarch_data
*jit_gdbarch_data
;
61 /* True if we want to see trace of jit level stuff. */
63 static bool jit_debug
= false;
65 /* Print a "jit" debug statement. */
67 #define jit_debug_printf(fmt, ...) \
68 debug_prefixed_printf_cond (jit_debug, "jit", fmt, ##__VA_ARGS__)
71 show_jit_debug (struct ui_file
*file
, int from_tty
,
72 struct cmd_list_element
*c
, const char *value
)
74 gdb_printf (file
, _("JIT debugging is %s.\n"), value
);
77 /* Implementation of the "maintenance info jit" command. */
80 maint_info_jit_cmd (const char *args
, int from_tty
)
82 inferior
*inf
= current_inferior ();
83 bool printed_header
= false;
85 gdb::optional
<ui_out_emit_table
> table_emitter
;
87 /* Print a line for each JIT-ed objfile. */
88 for (objfile
*obj
: inf
->pspace
->objfiles ())
90 if (obj
->jited_data
== nullptr)
95 table_emitter
.emplace (current_uiout
, 3, -1, "jit-created-objfiles");
97 /* The +2 allows for the leading '0x', then one character for
99 int addr_width
= 2 + (gdbarch_ptr_bit (obj
->arch ()) / 4);
101 /* The std::max here selects between the width of an address (as
102 a string) and the width of the column header string. */
103 current_uiout
->table_header (std::max (addr_width
, 22), ui_left
,
104 "jit_code_entry-address",
105 "jit_code_entry address");
106 current_uiout
->table_header (std::max (addr_width
, 15), ui_left
,
107 "symfile-address", "symfile address");
108 current_uiout
->table_header (20, ui_left
,
109 "symfile-size", "symfile size");
110 current_uiout
->table_body ();
112 printed_header
= true;
115 ui_out_emit_tuple
tuple_emitter (current_uiout
, "jit-objfile");
117 current_uiout
->field_core_addr ("jit_code_entry-address", obj
->arch (),
118 obj
->jited_data
->addr
);
119 current_uiout
->field_core_addr ("symfile-address", obj
->arch (),
120 obj
->jited_data
->symfile_addr
);
121 current_uiout
->field_unsigned ("symfile-size",
122 obj
->jited_data
->symfile_size
);
123 current_uiout
->text ("\n");
129 jit_reader (struct gdb_reader_funcs
*f
, gdb_dlhandle_up
&&h
)
130 : functions (f
), handle (std::move (h
))
136 functions
->destroy (functions
);
139 DISABLE_COPY_AND_ASSIGN (jit_reader
);
141 struct gdb_reader_funcs
*functions
;
142 gdb_dlhandle_up handle
;
145 /* One reader that has been loaded successfully, and can potentially be used to
148 static struct jit_reader
*loaded_jit_reader
= NULL
;
150 typedef struct gdb_reader_funcs
* (reader_init_fn_type
) (void);
151 static const char reader_init_fn_sym
[] = "gdb_init_reader";
153 /* Try to load FILE_NAME as a JIT debug info reader. */
155 static struct jit_reader
*
156 jit_reader_load (const char *file_name
)
158 reader_init_fn_type
*init_fn
;
159 struct gdb_reader_funcs
*funcs
= NULL
;
161 jit_debug_printf ("Opening shared object %s", file_name
);
163 gdb_dlhandle_up so
= gdb_dlopen (file_name
);
165 init_fn
= (reader_init_fn_type
*) gdb_dlsym (so
, reader_init_fn_sym
);
167 error (_("Could not locate initialization function: %s."),
170 if (gdb_dlsym (so
, "plugin_is_GPL_compatible") == NULL
)
171 error (_("Reader not GPL compatible."));
174 if (funcs
->reader_version
!= GDB_READER_INTERFACE_VERSION
)
175 error (_("Reader version does not match GDB version."));
177 return new jit_reader (funcs
, std::move (so
));
180 /* Provides the jit-reader-load command. */
183 jit_reader_load_command (const char *args
, int from_tty
)
186 error (_("No reader name provided."));
187 gdb::unique_xmalloc_ptr
<char> file (tilde_expand (args
));
189 if (loaded_jit_reader
!= NULL
)
190 error (_("JIT reader already loaded. Run jit-reader-unload first."));
192 if (!IS_ABSOLUTE_PATH (file
.get ()))
193 file
= xstrprintf ("%s%s%s", jit_reader_dir
.c_str (),
194 SLASH_STRING
, file
.get ());
196 loaded_jit_reader
= jit_reader_load (file
.get ());
197 reinit_frame_cache ();
198 jit_inferior_created_hook (current_inferior ());
201 /* Provides the jit-reader-unload command. */
204 jit_reader_unload_command (const char *args
, int from_tty
)
206 if (!loaded_jit_reader
)
207 error (_("No JIT reader loaded."));
209 reinit_frame_cache ();
210 jit_inferior_exit_hook (current_inferior ());
212 delete loaded_jit_reader
;
213 loaded_jit_reader
= NULL
;
216 /* Destructor for jiter_objfile_data. */
218 jiter_objfile_data::~jiter_objfile_data ()
220 if (this->jit_breakpoint
!= nullptr)
221 delete_breakpoint (this->jit_breakpoint
);
224 /* Fetch the jiter_objfile_data associated with OBJF. If no data exists
225 yet, make a new structure and attach it. */
227 static jiter_objfile_data
*
228 get_jiter_objfile_data (objfile
*objf
)
230 if (objf
->jiter_data
== nullptr)
231 objf
->jiter_data
.reset (new jiter_objfile_data ());
233 return objf
->jiter_data
.get ();
236 /* Remember OBJFILE has been created for struct jit_code_entry located
237 at inferior address ENTRY. */
240 add_objfile_entry (struct objfile
*objfile
, CORE_ADDR entry
,
241 CORE_ADDR symfile_addr
, ULONGEST symfile_size
)
243 gdb_assert (objfile
->jited_data
== nullptr);
245 objfile
->jited_data
.reset (new jited_objfile_data (entry
, symfile_addr
,
249 /* Helper function for reading the global JIT descriptor from remote
250 memory. Returns true if all went well, false otherwise. */
253 jit_read_descriptor (gdbarch
*gdbarch
,
254 jit_descriptor
*descriptor
,
258 struct type
*ptr_type
;
262 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
264 gdb_assert (jiter
!= nullptr);
265 jiter_objfile_data
*objf_data
= jiter
->jiter_data
.get ();
266 gdb_assert (objf_data
!= nullptr);
268 CORE_ADDR addr
= objf_data
->descriptor
->value_address (jiter
);
270 jit_debug_printf ("descriptor_addr = %s", paddress (gdbarch
, addr
));
272 /* Figure out how big the descriptor is on the remote and how to read it. */
273 ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
274 ptr_size
= TYPE_LENGTH (ptr_type
);
275 desc_size
= 8 + 2 * ptr_size
; /* Two 32-bit ints and two pointers. */
276 desc_buf
= (gdb_byte
*) alloca (desc_size
);
278 /* Read the descriptor. */
279 err
= target_read_memory (addr
, desc_buf
, desc_size
);
282 gdb_printf (gdb_stderr
, _("Unable to read JIT descriptor from "
287 /* Fix the endianness to match the host. */
288 descriptor
->version
= extract_unsigned_integer (&desc_buf
[0], 4, byte_order
);
289 descriptor
->action_flag
=
290 extract_unsigned_integer (&desc_buf
[4], 4, byte_order
);
291 descriptor
->relevant_entry
= extract_typed_address (&desc_buf
[8], ptr_type
);
292 descriptor
->first_entry
=
293 extract_typed_address (&desc_buf
[8 + ptr_size
], ptr_type
);
298 /* Helper function for reading a JITed code entry from remote memory. */
301 jit_read_code_entry (struct gdbarch
*gdbarch
,
302 CORE_ADDR code_addr
, struct jit_code_entry
*code_entry
)
305 struct type
*ptr_type
;
310 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
312 /* Figure out how big the entry is on the remote and how to read it. */
313 ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
314 ptr_size
= TYPE_LENGTH (ptr_type
);
316 /* Figure out where the uint64_t value will be. */
317 align_bytes
= type_align (builtin_type (gdbarch
)->builtin_uint64
);
319 off
= (off
+ (align_bytes
- 1)) & ~(align_bytes
- 1);
321 entry_size
= off
+ 8; /* Three pointers and one 64-bit int. */
322 entry_buf
= (gdb_byte
*) alloca (entry_size
);
324 /* Read the entry. */
325 err
= target_read_memory (code_addr
, entry_buf
, entry_size
);
327 error (_("Unable to read JIT code entry from remote memory!"));
329 /* Fix the endianness to match the host. */
330 ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
331 code_entry
->next_entry
= extract_typed_address (&entry_buf
[0], ptr_type
);
332 code_entry
->prev_entry
=
333 extract_typed_address (&entry_buf
[ptr_size
], ptr_type
);
334 code_entry
->symfile_addr
=
335 extract_typed_address (&entry_buf
[2 * ptr_size
], ptr_type
);
336 code_entry
->symfile_size
=
337 extract_unsigned_integer (&entry_buf
[off
], 8, byte_order
);
340 /* Proxy object for building a block. */
344 gdb_block (gdb_block
*parent
, CORE_ADDR begin
, CORE_ADDR end
,
349 name (name
!= nullptr ? xstrdup (name
) : nullptr)
352 /* The parent of this block. */
353 struct gdb_block
*parent
;
355 /* Points to the "real" block that is being built out of this
356 instance. This block will be added to a blockvector, which will
357 then be added to a symtab. */
358 struct block
*real_block
= nullptr;
360 /* The first and last code address corresponding to this block. */
361 CORE_ADDR begin
, end
;
363 /* The name of this block (if any). If this is non-NULL, the
364 FUNCTION symbol symbol is set to this value. */
365 gdb::unique_xmalloc_ptr
<char> name
;
368 /* Proxy object for building a symtab. */
372 explicit gdb_symtab (const char *file_name
)
373 : file_name (file_name
!= nullptr ? file_name
: "")
376 /* The list of blocks in this symtab. These will eventually be
377 converted to real blocks.
379 This is specifically a linked list, instead of, for example, a vector,
380 because the pointers are returned to the user's debug info reader. So
381 it's important that the objects don't change location during their
382 lifetime (which would happen with a vector of objects getting resized). */
383 std::forward_list
<gdb_block
> blocks
;
385 /* The number of blocks inserted. */
388 /* A mapping between line numbers to PC. */
389 gdb::unique_xmalloc_ptr
<struct linetable
> linetable
;
391 /* The source file for this symtab. */
392 std::string file_name
;
395 /* Proxy object for building an object. */
399 /* Symtabs of this object.
401 This is specifically a linked list, instead of, for example, a vector,
402 because the pointers are returned to the user's debug info reader. So
403 it's important that the objects don't change location during their
404 lifetime (which would happen with a vector of objects getting resized). */
405 std::forward_list
<gdb_symtab
> symtabs
;
408 /* The type of the `private' data passed around by the callback
411 struct jit_dbg_reader_data
413 /* Address of the jit_code_entry in the inferior's address space. */
414 CORE_ADDR entry_addr
;
416 /* The code entry, copied in our address space. */
417 const jit_code_entry
&entry
;
419 struct gdbarch
*gdbarch
;
422 /* The reader calls into this function to read data off the targets
425 static enum gdb_status
426 jit_target_read_impl (GDB_CORE_ADDR target_mem
, void *gdb_buf
, int len
)
428 int result
= target_read_memory ((CORE_ADDR
) target_mem
,
429 (gdb_byte
*) gdb_buf
, len
);
436 /* The reader calls into this function to create a new gdb_object
437 which it can then pass around to the other callbacks. Right now,
438 all that is required is allocating the memory. */
440 static struct gdb_object
*
441 jit_object_open_impl (struct gdb_symbol_callbacks
*cb
)
443 /* CB is not required right now, but sometime in the future we might
444 need a handle to it, and we'd like to do that without breaking
446 return new gdb_object
;
449 /* Readers call into this function to open a new gdb_symtab, which,
450 again, is passed around to other callbacks. */
452 static struct gdb_symtab
*
453 jit_symtab_open_impl (struct gdb_symbol_callbacks
*cb
,
454 struct gdb_object
*object
,
455 const char *file_name
)
457 /* CB stays unused. See comment in jit_object_open_impl. */
459 object
->symtabs
.emplace_front (file_name
);
460 return &object
->symtabs
.front ();
463 /* Called by readers to open a new gdb_block. This function also
464 inserts the new gdb_block in the correct place in the corresponding
467 static struct gdb_block
*
468 jit_block_open_impl (struct gdb_symbol_callbacks
*cb
,
469 struct gdb_symtab
*symtab
, struct gdb_block
*parent
,
470 GDB_CORE_ADDR begin
, GDB_CORE_ADDR end
, const char *name
)
472 /* Place the block at the beginning of the list, it will be sorted when the
473 symtab is finalized. */
474 symtab
->blocks
.emplace_front (parent
, begin
, end
, name
);
477 return &symtab
->blocks
.front ();
480 /* Readers call this to add a line mapping (from PC to line number) to
484 jit_symtab_line_mapping_add_impl (struct gdb_symbol_callbacks
*cb
,
485 struct gdb_symtab
*stab
, int nlines
,
486 struct gdb_line_mapping
*map
)
494 alloc_len
= sizeof (struct linetable
)
495 + (nlines
- 1) * sizeof (struct linetable_entry
);
496 stab
->linetable
.reset (XNEWVAR (struct linetable
, alloc_len
));
497 stab
->linetable
->nitems
= nlines
;
498 for (i
= 0; i
< nlines
; i
++)
500 stab
->linetable
->item
[i
].pc
= (CORE_ADDR
) map
[i
].pc
;
501 stab
->linetable
->item
[i
].line
= map
[i
].line
;
502 stab
->linetable
->item
[i
].is_stmt
= 1;
506 /* Called by readers to close a gdb_symtab. Does not need to do
507 anything as of now. */
510 jit_symtab_close_impl (struct gdb_symbol_callbacks
*cb
,
511 struct gdb_symtab
*stab
)
513 /* Right now nothing needs to be done here. We may need to do some
514 cleanup here in the future (again, without breaking the plugin
518 /* Transform STAB to a proper symtab, and add it it OBJFILE. */
521 finalize_symtab (struct gdb_symtab
*stab
, struct objfile
*objfile
)
523 struct compunit_symtab
*cust
;
524 size_t blockvector_size
;
525 CORE_ADDR begin
, end
;
526 struct blockvector
*bv
;
528 int actual_nblocks
= FIRST_LOCAL_BLOCK
+ stab
->nblocks
;
530 /* Sort the blocks in the order they should appear in the blockvector. */
531 stab
->blocks
.sort([] (const gdb_block
&a
, const gdb_block
&b
)
533 if (a
.begin
!= b
.begin
)
534 return a
.begin
< b
.begin
;
536 return a
.end
> b
.end
;
539 cust
= allocate_compunit_symtab (objfile
, stab
->file_name
.c_str ());
540 symtab
*filetab
= allocate_symtab (cust
, stab
->file_name
.c_str ());
541 add_compunit_symtab_to_objfile (cust
);
543 /* JIT compilers compile in memory. */
544 cust
->set_dirname (nullptr);
546 /* Copy over the linetable entry if one was provided. */
549 size_t size
= ((stab
->linetable
->nitems
- 1)
550 * sizeof (struct linetable_entry
)
551 + sizeof (struct linetable
));
552 filetab
->set_linetable ((struct linetable
*)
553 obstack_alloc (&objfile
->objfile_obstack
, size
));
554 memcpy (filetab
->linetable (), stab
->linetable
.get (), size
);
557 blockvector_size
= (sizeof (struct blockvector
)
558 + (actual_nblocks
- 1) * sizeof (struct block
*));
559 bv
= (struct blockvector
*) obstack_alloc (&objfile
->objfile_obstack
,
561 cust
->set_blockvector (bv
);
563 /* At the end of this function, (begin, end) will contain the PC range this
564 entire blockvector spans. */
565 BLOCKVECTOR_MAP (bv
) = NULL
;
566 begin
= stab
->blocks
.front ().begin
;
567 end
= stab
->blocks
.front ().end
;
568 BLOCKVECTOR_NBLOCKS (bv
) = actual_nblocks
;
570 /* First run over all the gdb_block objects, creating a real block
571 object for each. Simultaneously, keep setting the real_block
573 int block_idx
= FIRST_LOCAL_BLOCK
;
574 for (gdb_block
&gdb_block_iter
: stab
->blocks
)
576 struct block
*new_block
= allocate_block (&objfile
->objfile_obstack
);
577 struct symbol
*block_name
= new (&objfile
->objfile_obstack
) symbol
;
578 struct type
*block_type
= arch_type (objfile
->arch (),
583 BLOCK_MULTIDICT (new_block
)
584 = mdict_create_linear (&objfile
->objfile_obstack
, NULL
);
585 /* The address range. */
586 new_block
->set_start (gdb_block_iter
.begin
);
587 new_block
->set_end (gdb_block_iter
.end
);
590 block_name
->set_domain (VAR_DOMAIN
);
591 block_name
->set_aclass_index (LOC_BLOCK
);
592 block_name
->set_symtab (filetab
);
593 block_name
->set_type (lookup_function_type (block_type
));
594 block_name
->set_value_block (new_block
);
596 block_name
->m_name
= obstack_strdup (&objfile
->objfile_obstack
,
597 gdb_block_iter
.name
.get ());
599 new_block
->set_function (block_name
);
601 BLOCKVECTOR_BLOCK (bv
, block_idx
) = new_block
;
602 if (begin
> new_block
->start ())
603 begin
= new_block
->start ();
604 if (end
< new_block
->end ())
605 end
= new_block
->end ();
607 gdb_block_iter
.real_block
= new_block
;
612 /* Now add the special blocks. */
613 struct block
*block_iter
= NULL
;
614 for (enum block_enum i
: { GLOBAL_BLOCK
, STATIC_BLOCK
})
616 struct block
*new_block
;
618 new_block
= (i
== GLOBAL_BLOCK
619 ? allocate_global_block (&objfile
->objfile_obstack
)
620 : allocate_block (&objfile
->objfile_obstack
));
621 BLOCK_MULTIDICT (new_block
)
622 = mdict_create_linear (&objfile
->objfile_obstack
, NULL
);
623 new_block
->set_superblock (block_iter
);
624 block_iter
= new_block
;
626 new_block
->set_start (begin
);
627 new_block
->set_end (end
);
629 BLOCKVECTOR_BLOCK (bv
, i
) = new_block
;
631 if (i
== GLOBAL_BLOCK
)
632 set_block_compunit_symtab (new_block
, cust
);
635 /* Fill up the superblock fields for the real blocks, using the
636 real_block fields populated earlier. */
637 for (gdb_block
&gdb_block_iter
: stab
->blocks
)
639 if (gdb_block_iter
.parent
!= NULL
)
641 /* If the plugin specifically mentioned a parent block, we
643 gdb_block_iter
.real_block
->set_superblock
644 (gdb_block_iter
.parent
->real_block
);
649 /* And if not, we set a default parent block. */
650 gdb_block_iter
.real_block
->set_superblock
651 (BLOCKVECTOR_BLOCK (bv
, STATIC_BLOCK
));
656 /* Called when closing a gdb_objfile. Converts OBJ to a proper
660 jit_object_close_impl (struct gdb_symbol_callbacks
*cb
,
661 struct gdb_object
*obj
)
663 jit_dbg_reader_data
*priv_data
= (jit_dbg_reader_data
*) cb
->priv_data
;
664 std::string objfile_name
665 = string_printf ("<< JIT compiled code at %s >>",
666 paddress (priv_data
->gdbarch
,
667 priv_data
->entry
.symfile_addr
));
669 objfile
*objfile
= objfile::make (nullptr, objfile_name
.c_str (),
671 objfile
->per_bfd
->gdbarch
= priv_data
->gdbarch
;
673 for (gdb_symtab
&symtab
: obj
->symtabs
)
674 finalize_symtab (&symtab
, objfile
);
676 add_objfile_entry (objfile
, priv_data
->entry_addr
,
677 priv_data
->entry
.symfile_addr
,
678 priv_data
->entry
.symfile_size
);
683 /* Try to read CODE_ENTRY using the loaded jit reader (if any).
684 ENTRY_ADDR is the address of the struct jit_code_entry in the
685 inferior address space. */
688 jit_reader_try_read_symtab (gdbarch
*gdbarch
, jit_code_entry
*code_entry
,
689 CORE_ADDR entry_addr
)
692 jit_dbg_reader_data priv_data
698 struct gdb_reader_funcs
*funcs
;
699 struct gdb_symbol_callbacks callbacks
=
701 jit_object_open_impl
,
702 jit_symtab_open_impl
,
704 jit_symtab_close_impl
,
705 jit_object_close_impl
,
707 jit_symtab_line_mapping_add_impl
,
708 jit_target_read_impl
,
713 if (!loaded_jit_reader
)
716 gdb::byte_vector
gdb_mem (code_entry
->symfile_size
);
721 if (target_read_memory (code_entry
->symfile_addr
, gdb_mem
.data (),
722 code_entry
->symfile_size
))
725 catch (const gdb_exception
&e
)
732 funcs
= loaded_jit_reader
->functions
;
733 if (funcs
->read (funcs
, &callbacks
, gdb_mem
.data (),
734 code_entry
->symfile_size
)
740 jit_debug_printf ("Could not read symtab using the loaded JIT reader.");
745 /* Try to read CODE_ENTRY using BFD. ENTRY_ADDR is the address of the
746 struct jit_code_entry in the inferior address space. */
749 jit_bfd_try_read_symtab (struct jit_code_entry
*code_entry
,
750 CORE_ADDR entry_addr
,
751 struct gdbarch
*gdbarch
)
753 struct bfd_section
*sec
;
754 struct objfile
*objfile
;
755 const struct bfd_arch_info
*b
;
757 jit_debug_printf ("symfile_addr = %s, symfile_size = %s",
758 paddress (gdbarch
, code_entry
->symfile_addr
),
759 pulongest (code_entry
->symfile_size
));
761 gdb_bfd_ref_ptr
nbfd (gdb_bfd_open_from_target_memory
762 (code_entry
->symfile_addr
, code_entry
->symfile_size
, gnutarget
));
765 gdb_puts (_("Error opening JITed symbol file, ignoring it.\n"),
770 /* Check the format. NOTE: This initializes important data that GDB uses!
771 We would segfault later without this line. */
772 if (!bfd_check_format (nbfd
.get (), bfd_object
))
774 gdb_printf (gdb_stderr
, _("\
775 JITed symbol file is not an object file, ignoring it.\n"));
779 /* Check bfd arch. */
780 b
= gdbarch_bfd_arch_info (gdbarch
);
781 if (b
->compatible (b
, bfd_get_arch_info (nbfd
.get ())) != b
)
782 warning (_("JITed object file architecture %s is not compatible "
783 "with target architecture %s."),
784 bfd_get_arch_info (nbfd
.get ())->printable_name
,
787 /* Read the section address information out of the symbol file. Since the
788 file is generated by the JIT at runtime, it should all of the absolute
789 addresses that we care about. */
790 section_addr_info sai
;
791 for (sec
= nbfd
->sections
; sec
!= NULL
; sec
= sec
->next
)
792 if ((bfd_section_flags (sec
) & (SEC_ALLOC
|SEC_LOAD
)) != 0)
794 /* We assume that these virtual addresses are absolute, and do not
795 treat them as offsets. */
796 sai
.emplace_back (bfd_section_vma (sec
),
797 bfd_section_name (sec
),
801 /* This call does not take ownership of SAI. */
802 objfile
= symbol_file_add_from_bfd (nbfd
.get (),
803 bfd_get_filename (nbfd
.get ()), 0,
805 OBJF_SHARED
| OBJF_NOT_FILENAME
, NULL
);
807 add_objfile_entry (objfile
, entry_addr
, code_entry
->symfile_addr
,
808 code_entry
->symfile_size
);
811 /* This function registers code associated with a JIT code entry. It uses the
812 pointer and size pair in the entry to read the symbol file from the remote
813 and then calls symbol_file_add_from_local_memory to add it as though it were
814 a symbol file added by the user. */
817 jit_register_code (struct gdbarch
*gdbarch
,
818 CORE_ADDR entry_addr
, struct jit_code_entry
*code_entry
)
822 jit_debug_printf ("symfile_addr = %s, symfile_size = %s",
823 paddress (gdbarch
, code_entry
->symfile_addr
),
824 pulongest (code_entry
->symfile_size
));
826 success
= jit_reader_try_read_symtab (gdbarch
, code_entry
, entry_addr
);
829 jit_bfd_try_read_symtab (code_entry
, entry_addr
, gdbarch
);
832 /* Look up the objfile with this code entry address. */
834 static struct objfile
*
835 jit_find_objf_with_entry_addr (CORE_ADDR entry_addr
)
837 for (objfile
*objf
: current_program_space
->objfiles ())
839 if (objf
->jited_data
!= nullptr && objf
->jited_data
->addr
== entry_addr
)
846 /* This is called when a breakpoint is deleted. It updates the
847 inferior's cache, if needed. */
850 jit_breakpoint_deleted (struct breakpoint
*b
)
852 if (b
->type
!= bp_jit_event
)
855 for (bp_location
*iter
: b
->locations ())
857 for (objfile
*objf
: iter
->pspace
->objfiles ())
859 jiter_objfile_data
*jiter_data
= objf
->jiter_data
.get ();
861 if (jiter_data
!= nullptr
862 && jiter_data
->jit_breakpoint
== iter
->owner
)
864 jiter_data
->cached_code_address
= 0;
865 jiter_data
->jit_breakpoint
= nullptr;
871 /* (Re-)Initialize the jit breakpoints for JIT-producing objfiles in
875 jit_breakpoint_re_set_internal (struct gdbarch
*gdbarch
, program_space
*pspace
)
877 for (objfile
*the_objfile
: pspace
->objfiles ())
879 /* Skip separate debug objects. */
880 if (the_objfile
->separate_debug_objfile_backlink
!= nullptr)
883 if (the_objfile
->skip_jit_symbol_lookup
)
886 /* Lookup the registration symbol. If it is missing, then we
887 assume we are not attached to a JIT. */
888 bound_minimal_symbol reg_symbol
889 = lookup_minimal_symbol (jit_break_name
, nullptr, the_objfile
);
890 if (reg_symbol
.minsym
== NULL
891 || reg_symbol
.value_address () == 0)
893 /* No need to repeat the lookup the next time. */
894 the_objfile
->skip_jit_symbol_lookup
= true;
898 bound_minimal_symbol desc_symbol
899 = lookup_minimal_symbol (jit_descriptor_name
, NULL
, the_objfile
);
900 if (desc_symbol
.minsym
== NULL
901 || desc_symbol
.value_address () == 0)
903 /* No need to repeat the lookup the next time. */
904 the_objfile
->skip_jit_symbol_lookup
= true;
908 jiter_objfile_data
*objf_data
909 = get_jiter_objfile_data (the_objfile
);
910 objf_data
->register_code
= reg_symbol
.minsym
;
911 objf_data
->descriptor
= desc_symbol
.minsym
;
913 CORE_ADDR addr
= objf_data
->register_code
->value_address (the_objfile
);
914 jit_debug_printf ("breakpoint_addr = %s", paddress (gdbarch
, addr
));
916 /* Check if we need to re-create the breakpoint. */
917 if (objf_data
->cached_code_address
== addr
)
920 /* Delete the old breakpoint. */
921 if (objf_data
->jit_breakpoint
!= nullptr)
922 delete_breakpoint (objf_data
->jit_breakpoint
);
924 /* Put a breakpoint in the registration symbol. */
925 objf_data
->cached_code_address
= addr
;
926 objf_data
->jit_breakpoint
= create_jit_event_breakpoint (gdbarch
, addr
);
930 /* The private data passed around in the frame unwind callback
933 struct jit_unwind_private
935 /* Cached register values. See jit_frame_sniffer to see how this
937 std::unique_ptr
<detached_regcache
> regcache
;
939 /* The frame being unwound. */
940 struct frame_info
*this_frame
;
943 /* Sets the value of a particular register in this frame. */
946 jit_unwind_reg_set_impl (struct gdb_unwind_callbacks
*cb
, int dwarf_regnum
,
947 struct gdb_reg_value
*value
)
949 struct jit_unwind_private
*priv
;
952 priv
= (struct jit_unwind_private
*) cb
->priv_data
;
954 gdb_reg
= gdbarch_dwarf2_reg_to_regnum (get_frame_arch (priv
->this_frame
),
958 jit_debug_printf ("Could not recognize DWARF regnum %d", dwarf_regnum
);
963 priv
->regcache
->raw_supply (gdb_reg
, value
->value
);
968 reg_value_free_impl (struct gdb_reg_value
*value
)
973 /* Get the value of register REGNUM in the previous frame. */
975 static struct gdb_reg_value
*
976 jit_unwind_reg_get_impl (struct gdb_unwind_callbacks
*cb
, int regnum
)
978 struct jit_unwind_private
*priv
;
979 struct gdb_reg_value
*value
;
981 struct gdbarch
*frame_arch
;
983 priv
= (struct jit_unwind_private
*) cb
->priv_data
;
984 frame_arch
= get_frame_arch (priv
->this_frame
);
986 gdb_reg
= gdbarch_dwarf2_reg_to_regnum (frame_arch
, regnum
);
987 size
= register_size (frame_arch
, gdb_reg
);
988 value
= ((struct gdb_reg_value
*)
989 xmalloc (sizeof (struct gdb_reg_value
) + size
- 1));
990 value
->defined
= deprecated_frame_register_read (priv
->this_frame
, gdb_reg
,
993 value
->free
= reg_value_free_impl
;
997 /* gdb_reg_value has a free function, which must be called on each
998 saved register value. */
1001 jit_dealloc_cache (struct frame_info
*this_frame
, void *cache
)
1003 struct jit_unwind_private
*priv_data
= (struct jit_unwind_private
*) cache
;
1007 /* The frame sniffer for the pseudo unwinder.
1009 While this is nominally a frame sniffer, in the case where the JIT
1010 reader actually recognizes the frame, it does a lot more work -- it
1011 unwinds the frame and saves the corresponding register values in
1012 the cache. jit_frame_prev_register simply returns the saved
1016 jit_frame_sniffer (const struct frame_unwind
*self
,
1017 struct frame_info
*this_frame
, void **cache
)
1019 struct jit_unwind_private
*priv_data
;
1020 struct gdb_unwind_callbacks callbacks
;
1021 struct gdb_reader_funcs
*funcs
;
1023 callbacks
.reg_get
= jit_unwind_reg_get_impl
;
1024 callbacks
.reg_set
= jit_unwind_reg_set_impl
;
1025 callbacks
.target_read
= jit_target_read_impl
;
1027 if (loaded_jit_reader
== NULL
)
1030 funcs
= loaded_jit_reader
->functions
;
1032 gdb_assert (!*cache
);
1034 priv_data
= new struct jit_unwind_private
;
1036 /* Take a snapshot of current regcache. */
1037 priv_data
->regcache
.reset
1038 (new detached_regcache (get_frame_arch (this_frame
), true));
1039 priv_data
->this_frame
= this_frame
;
1041 callbacks
.priv_data
= priv_data
;
1043 /* Try to coax the provided unwinder to unwind the stack */
1044 if (funcs
->unwind (funcs
, &callbacks
) == GDB_SUCCESS
)
1046 jit_debug_printf ("Successfully unwound frame using JIT reader.");
1050 jit_debug_printf ("Could not unwind frame using JIT reader.");
1052 jit_dealloc_cache (this_frame
, *cache
);
1059 /* The frame_id function for the pseudo unwinder. Relays the call to
1060 the loaded plugin. */
1063 jit_frame_this_id (struct frame_info
*this_frame
, void **cache
,
1064 struct frame_id
*this_id
)
1066 struct jit_unwind_private priv
;
1067 struct gdb_frame_id frame_id
;
1068 struct gdb_reader_funcs
*funcs
;
1069 struct gdb_unwind_callbacks callbacks
;
1071 priv
.regcache
.reset ();
1072 priv
.this_frame
= this_frame
;
1074 /* We don't expect the frame_id function to set any registers, so we
1075 set reg_set to NULL. */
1076 callbacks
.reg_get
= jit_unwind_reg_get_impl
;
1077 callbacks
.reg_set
= NULL
;
1078 callbacks
.target_read
= jit_target_read_impl
;
1079 callbacks
.priv_data
= &priv
;
1081 gdb_assert (loaded_jit_reader
);
1082 funcs
= loaded_jit_reader
->functions
;
1084 frame_id
= funcs
->get_frame_id (funcs
, &callbacks
);
1085 *this_id
= frame_id_build (frame_id
.stack_address
, frame_id
.code_address
);
1088 /* Pseudo unwinder function. Reads the previously fetched value for
1089 the register from the cache. */
1091 static struct value
*
1092 jit_frame_prev_register (struct frame_info
*this_frame
, void **cache
, int reg
)
1094 struct jit_unwind_private
*priv
= (struct jit_unwind_private
*) *cache
;
1095 struct gdbarch
*gdbarch
;
1098 return frame_unwind_got_optimized (this_frame
, reg
);
1100 gdbarch
= priv
->regcache
->arch ();
1101 gdb_byte
*buf
= (gdb_byte
*) alloca (register_size (gdbarch
, reg
));
1102 enum register_status status
= priv
->regcache
->cooked_read (reg
, buf
);
1104 if (status
== REG_VALID
)
1105 return frame_unwind_got_bytes (this_frame
, reg
, buf
);
1107 return frame_unwind_got_optimized (this_frame
, reg
);
1110 /* Relay everything back to the unwinder registered by the JIT debug
1113 static const struct frame_unwind jit_frame_unwind
=
1117 default_frame_unwind_stop_reason
,
1119 jit_frame_prev_register
,
1126 /* This is the information that is stored at jit_gdbarch_data for each
1129 struct jit_gdbarch_data_type
1131 /* Has the (pseudo) unwinder been prepended? */
1132 int unwinder_registered
;
1135 /* Check GDBARCH and prepend the pseudo JIT unwinder if needed. */
1138 jit_prepend_unwinder (struct gdbarch
*gdbarch
)
1140 struct jit_gdbarch_data_type
*data
;
1143 = (struct jit_gdbarch_data_type
*) gdbarch_data (gdbarch
, jit_gdbarch_data
);
1144 if (!data
->unwinder_registered
)
1146 frame_unwind_prepend_unwinder (gdbarch
, &jit_frame_unwind
);
1147 data
->unwinder_registered
= 1;
1151 /* Register any already created translations. */
1154 jit_inferior_init (inferior
*inf
)
1156 struct jit_descriptor descriptor
;
1157 struct jit_code_entry cur_entry
;
1158 CORE_ADDR cur_entry_addr
;
1159 struct gdbarch
*gdbarch
= inf
->gdbarch
;
1160 program_space
*pspace
= inf
->pspace
;
1162 jit_debug_printf ("called");
1164 jit_prepend_unwinder (gdbarch
);
1166 jit_breakpoint_re_set_internal (gdbarch
, pspace
);
1168 for (objfile
*jiter
: pspace
->objfiles ())
1170 if (jiter
->jiter_data
== nullptr)
1173 /* Read the descriptor so we can check the version number and load
1174 any already JITed functions. */
1175 if (!jit_read_descriptor (gdbarch
, &descriptor
, jiter
))
1178 /* Check that the version number agrees with that we support. */
1179 if (descriptor
.version
!= 1)
1181 gdb_printf (gdb_stderr
,
1182 _("Unsupported JIT protocol version %ld "
1183 "in descriptor (expected 1)\n"),
1184 (long) descriptor
.version
);
1188 /* If we've attached to a running program, we need to check the
1189 descriptor to register any functions that were already
1191 for (cur_entry_addr
= descriptor
.first_entry
;
1192 cur_entry_addr
!= 0;
1193 cur_entry_addr
= cur_entry
.next_entry
)
1195 jit_read_code_entry (gdbarch
, cur_entry_addr
, &cur_entry
);
1197 /* This hook may be called many times during setup, so make sure
1198 we don't add the same symbol file twice. */
1199 if (jit_find_objf_with_entry_addr (cur_entry_addr
) != NULL
)
1202 jit_register_code (gdbarch
, cur_entry_addr
, &cur_entry
);
1207 /* Looks for the descriptor and registration symbols and breakpoints
1208 the registration function. If it finds both, it registers all the
1209 already JITed code. If it has already found the symbols, then it
1210 doesn't try again. */
1213 jit_inferior_created_hook (inferior
*inf
)
1215 jit_inferior_init (inf
);
1218 /* Exported routine to call to re-set the jit breakpoints,
1219 e.g. when a program is rerun. */
1222 jit_breakpoint_re_set (void)
1224 jit_breakpoint_re_set_internal (target_gdbarch (), current_program_space
);
1227 /* This function cleans up any code entries left over when the
1228 inferior exits. We get left over code when the inferior exits
1229 without unregistering its code, for example when it crashes. */
1232 jit_inferior_exit_hook (struct inferior
*inf
)
1234 for (objfile
*objf
: current_program_space
->objfiles_safe ())
1236 if (objf
->jited_data
!= nullptr && objf
->jited_data
->addr
!= 0)
1242 jit_event_handler (gdbarch
*gdbarch
, objfile
*jiter
)
1244 struct jit_descriptor descriptor
;
1246 /* If we get a JIT breakpoint event for this objfile, it is necessarily a
1248 gdb_assert (jiter
->jiter_data
!= nullptr);
1250 /* Read the descriptor from remote memory. */
1251 if (!jit_read_descriptor (gdbarch
, &descriptor
, jiter
))
1253 CORE_ADDR entry_addr
= descriptor
.relevant_entry
;
1255 /* Do the corresponding action. */
1256 switch (descriptor
.action_flag
)
1263 jit_code_entry code_entry
;
1264 jit_read_code_entry (gdbarch
, entry_addr
, &code_entry
);
1265 jit_register_code (gdbarch
, entry_addr
, &code_entry
);
1269 case JIT_UNREGISTER
:
1271 objfile
*jited
= jit_find_objf_with_entry_addr (entry_addr
);
1272 if (jited
== nullptr)
1273 gdb_printf (gdb_stderr
,
1274 _("Unable to find JITed code "
1275 "entry at address: %s\n"),
1276 paddress (gdbarch
, entry_addr
));
1284 error (_("Unknown action_flag value in JIT descriptor!"));
1289 /* Initialize the jit_gdbarch_data slot with an instance of struct
1290 jit_gdbarch_data_type */
1293 jit_gdbarch_data_init (struct obstack
*obstack
)
1295 struct jit_gdbarch_data_type
*data
=
1296 XOBNEW (obstack
, struct jit_gdbarch_data_type
);
1298 data
->unwinder_registered
= 0;
1303 void _initialize_jit ();
1307 jit_reader_dir
= relocate_gdb_directory (JIT_READER_DIR
,
1308 JIT_READER_DIR_RELOCATABLE
);
1309 add_setshow_boolean_cmd ("jit", class_maintenance
, &jit_debug
,
1310 _("Set JIT debugging."),
1311 _("Show JIT debugging."),
1312 _("When set, JIT debugging is enabled."),
1315 &setdebuglist
, &showdebuglist
);
1317 add_cmd ("jit", class_maintenance
, maint_info_jit_cmd
,
1318 _("Print information about JIT-ed code objects."),
1319 &maintenanceinfolist
);
1321 gdb::observers::inferior_created
.attach (jit_inferior_created_hook
, "jit");
1322 gdb::observers::inferior_execd
.attach (jit_inferior_created_hook
, "jit");
1323 gdb::observers::inferior_exit
.attach (jit_inferior_exit_hook
, "jit");
1324 gdb::observers::breakpoint_deleted
.attach (jit_breakpoint_deleted
, "jit");
1326 jit_gdbarch_data
= gdbarch_data_register_pre_init (jit_gdbarch_data_init
);
1327 if (is_dl_available ())
1329 struct cmd_list_element
*c
;
1331 c
= add_com ("jit-reader-load", no_class
, jit_reader_load_command
, _("\
1332 Load FILE as debug info reader and unwinder for JIT compiled code.\n\
1333 Usage: jit-reader-load FILE\n\
1334 Try to load file FILE as a debug info reader (and unwinder) for\n\
1335 JIT compiled code. The file is loaded from " JIT_READER_DIR
",\n\
1336 relocated relative to the GDB executable if required."));
1337 set_cmd_completer (c
, filename_completer
);
1339 c
= add_com ("jit-reader-unload", no_class
,
1340 jit_reader_unload_command
, _("\
1341 Unload the currently loaded JIT debug info reader.\n\
1342 Usage: jit-reader-unload\n\n\
1343 Do \"help jit-reader-load\" for info on loading debug info readers."));
1344 set_cmd_completer (c
, noop_completer
);