1 /* Work with executable files, for GDB.
3 Copyright (C) 1988-2013 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/>. */
26 #include "filenames.h"
29 #include "completer.h"
33 #include "arch-utils.h"
34 #include "gdbthread.h"
35 #include "progspace.h"
39 #include "readline/readline.h"
40 #include "gdb_string.h"
47 void (*deprecated_file_changed_hook) (char *);
49 /* Prototypes for local functions */
51 static void file_command (char *, int);
53 static void set_section_command (char *, int);
55 static void exec_files_info (struct target_ops *);
57 static void init_exec_ops (void);
59 void _initialize_exec (void);
61 /* The target vector for executable files. */
63 struct target_ops exec_ops;
65 /* True if the exec target is pushed on the stack. */
66 static int using_exec_ops;
68 /* Whether to open exec and core files read-only or read-write. */
72 show_write_files (struct ui_file *file, int from_tty,
73 struct cmd_list_element *c, const char *value)
75 fprintf_filtered (file, _("Writing into executable and core files is %s.\n"),
81 exec_open (char *args, int from_tty)
83 target_preopen (from_tty);
84 exec_file_attach (args, from_tty);
87 /* Close and clear exec_bfd. If we end up with no target sections to
88 read memory from, this unpushes the exec_ops target. */
99 /* Removing target sections may close the exec_ops target.
100 Clear exec_bfd before doing so to prevent recursion. */
104 remove_target_sections (&exec_bfd);
106 xfree (exec_filename);
107 exec_filename = NULL;
111 /* This is the target_close implementation. Clears all target
112 sections and closes all executable bfds from all program spaces. */
120 struct program_space *ss;
121 struct cleanup *old_chain;
123 old_chain = save_current_program_space ();
126 set_current_program_space (ss);
128 /* Delete all target sections. */
130 (current_target_sections,
131 -resize_section_table (current_target_sections, 0));
136 do_cleanups (old_chain);
141 exec_file_clear (int from_tty)
143 /* Remove exec file. */
147 printf_unfiltered (_("No executable file now.\n"));
150 /* Set FILENAME as the new exec file.
152 This function is intended to be behave essentially the same
153 as exec_file_command, except that the latter will detect when
154 a target is being debugged, and will ask the user whether it
155 should be shut down first. (If the answer is "no", then the
156 new file is ignored.)
158 This file is used by exec_file_command, to do the work of opening
159 and processing the exec file after any prompting has happened.
161 And, it is used by child_attach, when the attach command was
162 given a pid but not a exec pathname, and the attach command could
163 figure out the pathname from the pid. (In this case, we shouldn't
164 ask the user whether the current target should be shut down --
165 we're supplying the exec pathname late for good reason.) */
168 exec_file_attach (char *filename, int from_tty)
170 /* Remove any previous exec file. */
173 /* Now open and digest the file the user requested, if any. */
178 printf_unfiltered (_("No executable file now.\n"));
180 set_gdbarch_from_file (NULL);
184 struct cleanup *cleanups;
185 char *scratch_pathname, *canonical_pathname;
187 struct target_section *sections = NULL, *sections_end = NULL;
190 scratch_chan = openp (getenv ("PATH"),
191 OPF_TRY_CWD_FIRST | OPF_DISABLE_REALPATH, filename,
192 write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
194 #if defined(__GO32__) || defined(_WIN32) || defined(__CYGWIN__)
195 if (scratch_chan < 0)
197 char *exename = alloca (strlen (filename) + 5);
199 strcat (strcpy (exename, filename), ".exe");
200 scratch_chan = openp (getenv ("PATH"),
201 OPF_TRY_CWD_FIRST | OPF_DISABLE_REALPATH,
203 write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
207 if (scratch_chan < 0)
208 perror_with_name (filename);
210 cleanups = make_cleanup (xfree, scratch_pathname);
212 /* gdb_bfd_open (and its variants) prefers canonicalized pathname for
213 better BFD caching. */
214 canonical_pathname = gdb_realpath (scratch_pathname);
215 make_cleanup (xfree, canonical_pathname);
218 exec_bfd = gdb_bfd_fopen (canonical_pathname, gnutarget,
219 FOPEN_RUB, scratch_chan);
221 exec_bfd = gdb_bfd_open (canonical_pathname, gnutarget, scratch_chan);
225 error (_("\"%s\": could not open as an executable file: %s"),
226 scratch_pathname, bfd_errmsg (bfd_get_error ()));
229 gdb_assert (exec_filename == NULL);
230 exec_filename = xstrdup (scratch_pathname);
232 if (!bfd_check_format_matches (exec_bfd, bfd_object, &matching))
234 /* Make sure to close exec_bfd, or else "run" might try to use
237 error (_("\"%s\": not in executable format: %s"),
239 gdb_bfd_errmsg (bfd_get_error (), matching));
242 if (build_section_table (exec_bfd, §ions, §ions_end))
244 /* Make sure to close exec_bfd, or else "run" might try to use
247 error (_("\"%s\": can't find the file sections: %s"),
248 scratch_pathname, bfd_errmsg (bfd_get_error ()));
251 exec_bfd_mtime = bfd_get_mtime (exec_bfd);
255 set_gdbarch_from_file (exec_bfd);
257 /* Add the executable's sections to the current address spaces'
258 list of sections. This possibly pushes the exec_ops
260 add_target_sections (&exec_bfd, sections, sections_end);
263 /* Tell display code (if any) about the changed file name. */
264 if (deprecated_exec_file_display_hook)
265 (*deprecated_exec_file_display_hook) (filename);
267 do_cleanups (cleanups);
269 bfd_cache_close_all ();
270 observer_notify_executable_changed ();
273 /* Process the first arg in ARGS as the new exec file.
275 Note that we have to explicitly ignore additional args, since we can
276 be called from file_command(), which also calls symbol_file_command()
277 which can take multiple args.
279 If ARGS is NULL, we just want to close the exec file. */
282 exec_file_command (char *args, int from_tty)
287 if (from_tty && target_has_execution
288 && !query (_("A program is being debugged already.\n"
289 "Are you sure you want to change the file? ")))
290 error (_("File not changed."));
294 struct cleanup *cleanups;
296 /* Scan through the args and pick up the first non option arg
299 argv = gdb_buildargv (args);
300 cleanups = make_cleanup_freeargv (argv);
302 for (; (*argv != NULL) && (**argv == '-'); argv++)
306 error (_("No executable file name was specified"));
308 filename = tilde_expand (*argv);
309 make_cleanup (xfree, filename);
310 exec_file_attach (filename, from_tty);
312 do_cleanups (cleanups);
315 exec_file_attach (NULL, from_tty);
318 /* Set both the exec file and the symbol file, in one command.
319 What a novelty. Why did GDB go through four major releases before this
320 command was added? */
323 file_command (char *arg, int from_tty)
325 /* FIXME, if we lose on reading the symbol file, we should revert
326 the exec file, but that's rough. */
327 exec_file_command (arg, from_tty);
328 symbol_file_command (arg, from_tty);
329 if (deprecated_file_changed_hook)
330 deprecated_file_changed_hook (arg);
334 /* Locate all mappable sections of a BFD file.
335 table_pp_char is a char * to get it through bfd_map_over_sections;
336 we cast it back to its proper type. */
339 add_to_section_table (bfd *abfd, struct bfd_section *asect,
342 struct target_section **table_pp = (struct target_section **) table_pp_char;
345 gdb_assert (abfd == asect->owner);
347 /* Check the section flags, but do not discard zero-length sections, since
348 some symbols may still be attached to this section. For instance, we
349 encountered on sparc-solaris 2.10 a shared library with an empty .bss
350 section to which a symbol named "_end" was attached. The address
351 of this symbol still needs to be relocated. */
352 aflag = bfd_get_section_flags (abfd, asect);
353 if (!(aflag & SEC_ALLOC))
356 (*table_pp)->owner = NULL;
357 (*table_pp)->the_bfd_section = asect;
358 (*table_pp)->addr = bfd_section_vma (abfd, asect);
359 (*table_pp)->endaddr = (*table_pp)->addr + bfd_section_size (abfd, asect);
364 resize_section_table (struct target_section_table *table, int num_added)
369 old_count = table->sections_end - table->sections;
371 new_count = num_added + old_count;
375 table->sections = xrealloc (table->sections,
376 sizeof (struct target_section) * new_count);
377 table->sections_end = table->sections + new_count;
381 xfree (table->sections);
382 table->sections = table->sections_end = NULL;
388 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
389 Returns 0 if OK, 1 on error. */
392 build_section_table (struct bfd *some_bfd, struct target_section **start,
393 struct target_section **end)
397 count = bfd_count_sections (some_bfd);
400 *start = (struct target_section *) xmalloc (count * sizeof (**start));
402 bfd_map_over_sections (some_bfd, add_to_section_table, (char *) end);
403 if (*end > *start + count)
404 internal_error (__FILE__, __LINE__,
405 _("failed internal consistency check"));
406 /* We could realloc the table, but it probably loses for most files. */
410 /* Add the sections array defined by [SECTIONS..SECTIONS_END[ to the
411 current set of target sections. */
414 add_target_sections (void *owner,
415 struct target_section *sections,
416 struct target_section *sections_end)
419 struct target_section_table *table = current_target_sections;
421 count = sections_end - sections;
425 int space = resize_section_table (table, count);
428 for (i = 0; i < count; ++i)
430 table->sections[space + i] = sections[i];
431 table->sections[space + i].owner = owner;
434 /* If these are the first file sections we can provide memory
435 from, push the file_stratum target. */
439 push_target (&exec_ops);
444 /* Remove all target sections owned by OWNER.
445 OWNER must be the same value passed to add_target_sections. */
448 remove_target_sections (void *owner)
450 struct target_section *src, *dest;
451 struct target_section_table *table = current_target_sections;
453 gdb_assert (owner != NULL);
455 dest = table->sections;
456 for (src = table->sections; src < table->sections_end; src++)
457 if (src->owner != owner)
459 /* Keep this section. */
465 /* If we've dropped any sections, resize the section table. */
470 old_count = resize_section_table (table, dest - src);
472 /* If we don't have any more sections to read memory from,
473 remove the file_stratum target from the stack. */
474 if (old_count + (dest - src) == 0)
476 struct program_space *pspace;
479 if (pspace->target_sections.sections
480 != pspace->target_sections.sections_end)
483 unpush_target (&exec_ops);
491 section_table_available_memory (VEC(mem_range_s) *memory,
492 CORE_ADDR memaddr, ULONGEST len,
493 struct target_section *sections,
494 struct target_section *sections_end)
496 struct target_section *p;
498 for (p = sections; p < sections_end; p++)
500 if ((bfd_get_section_flags (p->the_bfd_section->owner,
502 & SEC_READONLY) == 0)
505 /* Copy the meta-data, adjusted. */
506 if (mem_ranges_overlap (p->addr, p->endaddr - p->addr, memaddr, len))
508 ULONGEST lo1, hi1, lo2, hi2;
517 r = VEC_safe_push (mem_range_s, memory, NULL);
519 r->start = max (lo1, lo2);
520 r->length = min (hi1, hi2) - r->start;
528 section_table_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf,
529 ULONGEST offset, LONGEST len,
530 struct target_section *sections,
531 struct target_section *sections_end,
532 const char *section_name)
535 struct target_section *p;
536 ULONGEST memaddr = offset;
537 ULONGEST memend = memaddr + len;
540 internal_error (__FILE__, __LINE__,
541 _("failed internal consistency check"));
543 for (p = sections; p < sections_end; p++)
545 struct bfd_section *asect = p->the_bfd_section;
546 bfd *abfd = asect->owner;
548 if (section_name && strcmp (section_name, asect->name) != 0)
549 continue; /* not the section we need. */
550 if (memaddr >= p->addr)
552 if (memend <= p->endaddr)
554 /* Entire transfer is within this section. */
556 res = bfd_set_section_contents (abfd, asect,
557 writebuf, memaddr - p->addr,
560 res = bfd_get_section_contents (abfd, asect,
561 readbuf, memaddr - p->addr,
563 return (res != 0) ? len : 0;
565 else if (memaddr >= p->endaddr)
567 /* This section ends before the transfer starts. */
572 /* This section overlaps the transfer. Just do half. */
573 len = p->endaddr - memaddr;
575 res = bfd_set_section_contents (abfd, asect,
576 writebuf, memaddr - p->addr,
579 res = bfd_get_section_contents (abfd, asect,
580 readbuf, memaddr - p->addr,
582 return (res != 0) ? len : 0;
587 return 0; /* We can't help. */
590 static struct target_section_table *
591 exec_get_section_table (struct target_ops *ops)
593 return current_target_sections;
597 exec_xfer_partial (struct target_ops *ops, enum target_object object,
598 const char *annex, gdb_byte *readbuf,
599 const gdb_byte *writebuf,
600 ULONGEST offset, LONGEST len)
602 struct target_section_table *table = target_get_section_table (ops);
604 if (object == TARGET_OBJECT_MEMORY)
605 return section_table_xfer_memory_partial (readbuf, writebuf,
616 print_section_info (struct target_section_table *t, bfd *abfd)
618 struct gdbarch *gdbarch = gdbarch_from_bfd (abfd);
619 struct target_section *p;
620 /* FIXME: 16 is not wide enough when gdbarch_addr_bit > 64. */
621 int wid = gdbarch_addr_bit (gdbarch) <= 32 ? 8 : 16;
623 printf_filtered ("\t`%s', ", bfd_get_filename (abfd));
625 printf_filtered (_("file type %s.\n"), bfd_get_target (abfd));
626 if (abfd == exec_bfd)
628 /* gcc-3.4 does not like the initialization in
629 <p == t->sections_end>. */
630 bfd_vma displacement = 0;
633 for (p = t->sections; p < t->sections_end; p++)
635 struct bfd_section *psect = p->the_bfd_section;
636 bfd *pbfd = psect->owner;
638 if ((bfd_get_section_flags (pbfd, psect) & (SEC_ALLOC | SEC_LOAD))
639 != (SEC_ALLOC | SEC_LOAD))
642 if (bfd_get_section_vma (pbfd, psect) <= abfd->start_address
643 && abfd->start_address < (bfd_get_section_vma (pbfd, psect)
644 + bfd_get_section_size (psect)))
646 displacement = p->addr - bfd_get_section_vma (pbfd, psect);
650 if (p == t->sections_end)
651 warning (_("Cannot find section for the entry point of %s."),
652 bfd_get_filename (abfd));
654 entry_point = gdbarch_addr_bits_remove (gdbarch,
655 bfd_get_start_address (abfd)
657 printf_filtered (_("\tEntry point: %s\n"),
658 paddress (gdbarch, entry_point));
660 for (p = t->sections; p < t->sections_end; p++)
662 struct bfd_section *psect = p->the_bfd_section;
663 bfd *pbfd = psect->owner;
665 printf_filtered ("\t%s", hex_string_custom (p->addr, wid));
666 printf_filtered (" - %s", hex_string_custom (p->endaddr, wid));
668 /* FIXME: A format of "08l" is not wide enough for file offsets
669 larger than 4GB. OTOH, making it "016l" isn't desirable either
670 since most output will then be much wider than necessary. It
671 may make sense to test the size of the file and choose the
672 format string accordingly. */
673 /* FIXME: i18n: Need to rewrite this sentence. */
675 printf_filtered (" @ %s",
676 hex_string_custom (psect->filepos, 8));
677 printf_filtered (" is %s", bfd_section_name (pbfd, psect));
679 printf_filtered (" in %s", bfd_get_filename (pbfd));
680 printf_filtered ("\n");
685 exec_files_info (struct target_ops *t)
688 print_section_info (current_target_sections, exec_bfd);
690 puts_filtered (_("\t<no file loaded>\n"));
694 set_section_command (char *args, int from_tty)
696 struct target_section *p;
699 unsigned long secaddr;
702 struct target_section_table *table;
705 error (_("Must specify section name and its virtual address"));
707 /* Parse out section name. */
708 for (secname = args; !isspace (*args); args++);
709 seclen = args - secname;
711 /* Parse out new virtual address. */
712 secaddr = parse_and_eval_address (args);
714 table = current_target_sections;
715 for (p = table->sections; p < table->sections_end; p++)
717 if (!strncmp (secname, bfd_section_name (p->bfd,
718 p->the_bfd_section), seclen)
719 && bfd_section_name (p->bfd, p->the_bfd_section)[seclen] == '\0')
721 offset = secaddr - p->addr;
723 p->endaddr += offset;
725 exec_files_info (&exec_ops);
729 if (seclen >= sizeof (secprint))
730 seclen = sizeof (secprint) - 1;
731 strncpy (secprint, secname, seclen);
732 secprint[seclen] = '\0';
733 error (_("Section %s not found"), secprint);
736 /* If we can find a section in FILENAME with BFD index INDEX, adjust
740 exec_set_section_address (const char *filename, int index, CORE_ADDR address)
742 struct target_section *p;
743 struct target_section_table *table;
745 table = current_target_sections;
746 for (p = table->sections; p < table->sections_end; p++)
748 if (filename_cmp (filename, p->the_bfd_section->owner->filename) == 0
749 && index == p->the_bfd_section->index)
751 p->endaddr += address - p->addr;
757 /* If mourn is being called in all the right places, this could be say
758 `gdb internal error' (since generic_mourn calls
759 breakpoint_init_inferior). */
762 ignore (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt)
768 exec_has_memory (struct target_ops *ops)
770 /* We can provide memory if we have any file/target sections to read
772 return (current_target_sections->sections
773 != current_target_sections->sections_end);
776 /* Find mapped memory. */
779 exec_set_find_memory_regions (int (*func) (find_memory_region_ftype, void *))
781 exec_ops.to_find_memory_regions = func;
784 static char *exec_make_note_section (bfd *, int *);
786 /* Fill in the exec file target vector. Very few entries need to be
792 exec_ops.to_shortname = "exec";
793 exec_ops.to_longname = "Local exec file";
794 exec_ops.to_doc = "Use an executable file as a target.\n\
795 Specify the filename of the executable file.";
796 exec_ops.to_open = exec_open;
797 exec_ops.to_close = exec_close_1;
798 exec_ops.to_attach = find_default_attach;
799 exec_ops.to_xfer_partial = exec_xfer_partial;
800 exec_ops.to_get_section_table = exec_get_section_table;
801 exec_ops.to_files_info = exec_files_info;
802 exec_ops.to_insert_breakpoint = ignore;
803 exec_ops.to_remove_breakpoint = ignore;
804 exec_ops.to_create_inferior = find_default_create_inferior;
805 exec_ops.to_stratum = file_stratum;
806 exec_ops.to_has_memory = exec_has_memory;
807 exec_ops.to_make_corefile_notes = exec_make_note_section;
808 exec_ops.to_magic = OPS_MAGIC;
812 _initialize_exec (void)
814 struct cmd_list_element *c;
820 c = add_cmd ("file", class_files, file_command, _("\
821 Use FILE as program to be debugged.\n\
822 It is read for its symbols, for getting the contents of pure memory,\n\
823 and it is the program executed when you use the `run' command.\n\
824 If FILE cannot be found as specified, your execution directory path\n\
825 ($PATH) is searched for a command of that name.\n\
826 No arg means to have no executable file and no symbols."), &cmdlist);
827 set_cmd_completer (c, filename_completer);
830 c = add_cmd ("exec-file", class_files, exec_file_command, _("\
831 Use FILE as program for getting contents of pure memory.\n\
832 If FILE cannot be found as specified, your execution directory path\n\
833 is searched for a command of that name.\n\
834 No arg means have no executable file."), &cmdlist);
835 set_cmd_completer (c, filename_completer);
837 add_com ("section", class_files, set_section_command, _("\
838 Change the base address of section SECTION of the exec file to ADDR.\n\
839 This can be used if the exec file does not contain section addresses,\n\
840 (such as in the a.out format), or when the addresses specified in the\n\
841 file itself are wrong. Each section must be changed separately. The\n\
842 ``info files'' command lists all the sections and their addresses."));
844 add_setshow_boolean_cmd ("write", class_support, &write_files, _("\
845 Set writing into executable and core files."), _("\
846 Show writing into executable and core files."), NULL,
849 &setlist, &showlist);
851 add_target_with_completer (&exec_ops, filename_completer);
855 exec_make_note_section (bfd *obfd, int *note_size)
857 error (_("Can't create a corefile"));