1 /* ELF emulation code for targets using elf.em.
2 Copyright (C) 1991-2020 Free Software Foundation, Inc.
4 This file is part of the GNU Binutils.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
23 #include "libiberty.h"
24 #include "filenames.h"
25 #include "safe-ctype.h"
35 #include "ldbuildid.h"
49 /* Style of .note.gnu.build-id section. */
50 const char *ldelf_emit_note_gnu_build_id
;
52 /* These variables are required to pass information back and forth
53 between after_open and check_needed and stat_needed and vercheck. */
55 static struct bfd_link_needed_list
*global_needed
;
56 static lang_input_statement_type
*global_found
;
57 static struct stat global_stat
;
58 static struct bfd_link_needed_list
*global_vercheck_needed
;
59 static bfd_boolean global_vercheck_failed
;
62 ldelf_after_parse (void)
64 if (bfd_link_pie (&link_info
))
65 link_info
.flags_1
|= (bfd_vma
) DF_1_PIE
;
67 if (bfd_link_executable (&link_info
)
68 && link_info
.nointerp
)
70 if (link_info
.dynamic_undefined_weak
> 0)
71 einfo (_("%P: warning: -z dynamic-undefined-weak ignored\n"));
72 link_info
.dynamic_undefined_weak
= 0;
74 after_parse_default ();
77 /* Handle the generation of DT_NEEDED tags. */
80 ldelf_load_symbols (lang_input_statement_type
*entry
)
84 /* Tell the ELF linker that we don't want the output file to have a
85 DT_NEEDED entry for this file, unless it is used to resolve
86 references in a regular object. */
87 if (entry
->flags
.add_DT_NEEDED_for_regular
)
88 link_class
= DYN_AS_NEEDED
;
90 /* Tell the ELF linker that we don't want the output file to have a
91 DT_NEEDED entry for any dynamic library in DT_NEEDED tags from
93 if (!entry
->flags
.add_DT_NEEDED_for_dynamic
)
94 link_class
|= DYN_NO_ADD_NEEDED
;
96 if (entry
->flags
.just_syms
97 && (bfd_get_file_flags (entry
->the_bfd
) & DYNAMIC
) != 0)
98 einfo (_("%F%P: %pB: --just-symbols may not be used on DSO\n"),
102 || (bfd_get_file_flags (entry
->the_bfd
) & DYNAMIC
) == 0)
105 bfd_elf_set_dyn_lib_class (entry
->the_bfd
,
106 (enum dynamic_lib_link_class
) link_class
);
108 /* Continue on with normal load_symbols processing. */
112 /* On Linux, it's possible to have different versions of the same
113 shared library linked against different versions of libc. The
114 dynamic linker somehow tags which libc version to use in
115 /etc/ld.so.cache, and, based on the libc that it sees in the
116 executable, chooses which version of the shared library to use.
118 We try to do a similar check here by checking whether this shared
119 library needs any other shared libraries which may conflict with
120 libraries we have already included in the link. If it does, we
121 skip it, and try to find another shared library farther on down the
124 This is called via lang_for_each_input_file.
125 GLOBAL_VERCHECK_NEEDED is the list of objects needed by the object
126 which we are checking. This sets GLOBAL_VERCHECK_FAILED if we find
127 a conflicting version. */
130 ldelf_vercheck (lang_input_statement_type
*s
)
133 struct bfd_link_needed_list
*l
;
135 if (global_vercheck_failed
)
137 if (s
->the_bfd
== NULL
138 || (bfd_get_file_flags (s
->the_bfd
) & DYNAMIC
) == 0)
141 soname
= bfd_elf_get_dt_soname (s
->the_bfd
);
143 soname
= lbasename (bfd_get_filename (s
->the_bfd
));
145 for (l
= global_vercheck_needed
; l
!= NULL
; l
= l
->next
)
149 if (filename_cmp (soname
, l
->name
) == 0)
151 /* Probably can't happen, but it's an easy check. */
155 if (strchr (l
->name
, '/') != NULL
)
158 suffix
= strstr (l
->name
, ".so.");
162 suffix
+= sizeof ".so." - 1;
164 if (filename_ncmp (soname
, l
->name
, suffix
- l
->name
) == 0)
166 /* Here we know that S is a dynamic object FOO.SO.VER1, and
167 the object we are considering needs a dynamic object
168 FOO.SO.VER2, and VER1 and VER2 are different. This
169 appears to be a version mismatch, so we tell the caller
170 to try a different version of this library. */
171 global_vercheck_failed
= TRUE
;
178 /* See if an input file matches a DT_NEEDED entry by running stat on
182 ldelf_stat_needed (lang_input_statement_type
*s
)
188 if (global_found
!= NULL
)
190 if (s
->the_bfd
== NULL
)
193 /* If this input file was an as-needed entry, and wasn't found to be
194 needed at the stage it was linked, then don't say we have loaded it. */
195 if ((bfd_elf_get_dyn_lib_class (s
->the_bfd
) & DYN_AS_NEEDED
) != 0)
198 if (bfd_stat (s
->the_bfd
, &st
) != 0)
200 einfo (_("%P: %pB: bfd_stat failed: %E\n"), s
->the_bfd
);
204 /* Some operating systems, e.g. Windows, do not provide a meaningful
205 st_ino; they always set it to zero. (Windows does provide a
206 meaningful st_dev.) Do not indicate a duplicate library in that
207 case. While there is no guarantee that a system that provides
208 meaningful inode numbers will never set st_ino to zero, this is
209 merely an optimization, so we do not need to worry about false
211 if (st
.st_dev
== global_stat
.st_dev
212 && st
.st_ino
== global_stat
.st_ino
219 /* We issue a warning if it looks like we are including two
220 different versions of the same shared library. For example,
221 there may be a problem if -lc picks up libc.so.6 but some other
222 shared library has a DT_NEEDED entry of libc.so.5. This is a
223 heuristic test, and it will only work if the name looks like
224 NAME.so.VERSION. FIXME: Depending on file names is error-prone.
225 If we really want to issue warnings about mixing version numbers
226 of shared libraries, we need to find a better way. */
228 if (strchr (global_needed
->name
, '/') != NULL
)
230 suffix
= strstr (global_needed
->name
, ".so.");
233 suffix
+= sizeof ".so." - 1;
235 soname
= bfd_elf_get_dt_soname (s
->the_bfd
);
237 soname
= lbasename (s
->filename
);
239 if (filename_ncmp (soname
, global_needed
->name
,
240 suffix
- global_needed
->name
) == 0)
241 einfo (_("%P: warning: %s, needed by %pB, may conflict with %s\n"),
242 global_needed
->name
, global_needed
->by
, soname
);
245 /* This function is called for each possible name for a dynamic object
246 named by a DT_NEEDED entry. The FORCE parameter indicates whether
247 to skip the check for a conflicting version. */
250 ldelf_try_needed (struct dt_needed
*needed
, int force
, int is_linux
)
253 const char *name
= needed
->name
;
257 abfd
= bfd_openr (name
, bfd_get_target (link_info
.output_bfd
));
261 info_msg (_("attempt to open %s failed\n"), name
);
265 track_dependency_files (name
);
267 /* Linker needs to decompress sections. */
268 abfd
->flags
|= BFD_DECOMPRESS
;
270 if (! bfd_check_format (abfd
, bfd_object
))
275 if ((bfd_get_file_flags (abfd
) & DYNAMIC
) == 0)
281 /* For DT_NEEDED, they have to match. */
282 if (abfd
->xvec
!= link_info
.output_bfd
->xvec
)
288 /* Check whether this object would include any conflicting library
289 versions. If FORCE is set, then we skip this check; we use this
290 the second time around, if we couldn't find any compatible
291 instance of the shared library. */
295 struct bfd_link_needed_list
*needs
;
297 if (! bfd_elf_get_bfd_needed_list (abfd
, &needs
))
298 einfo (_("%F%P: %pB: bfd_elf_get_bfd_needed_list failed: %E\n"), abfd
);
302 global_vercheck_needed
= needs
;
303 global_vercheck_failed
= FALSE
;
304 lang_for_each_input_file (ldelf_vercheck
);
305 if (global_vercheck_failed
)
308 /* Return FALSE to force the caller to move on to try
309 another file on the search path. */
313 /* But wait! It gets much worse. On Linux, if a shared
314 library does not use libc at all, we are supposed to skip
315 it the first time around in case we encounter a shared
316 library later on with the same name which does use the
317 version of libc that we want. This is much too horrible
318 to use on any system other than Linux. */
321 struct bfd_link_needed_list
*l
;
323 for (l
= needs
; l
!= NULL
; l
= l
->next
)
324 if (CONST_STRNEQ (l
->name
, "libc.so"))
335 /* We've found a dynamic object matching the DT_NEEDED entry. */
337 /* We have already checked that there is no other input file of the
338 same name. We must now check again that we are not including the
339 same file twice. We need to do this because on many systems
340 libc.so is a symlink to, e.g., libc.so.1. The SONAME entry will
341 reference libc.so.1. If we have already included libc.so, we
342 don't want to include libc.so.1 if they are the same file, and we
343 can only check that using stat. */
345 if (bfd_stat (abfd
, &global_stat
) != 0)
346 einfo (_("%F%P: %pB: bfd_stat failed: %E\n"), abfd
);
348 /* First strip off everything before the last '/'. */
349 soname
= lbasename (bfd_get_filename (abfd
));
352 info_msg (_("found %s at %s\n"), soname
, name
);
355 lang_for_each_input_file (ldelf_stat_needed
);
356 if (global_found
!= NULL
)
358 /* Return TRUE to indicate that we found the file, even though
359 we aren't going to do anything with it. */
363 /* Specify the soname to use. */
364 bfd_elf_set_dt_needed_name (abfd
, soname
);
366 /* Tell the ELF linker that we don't want the output file to have a
367 DT_NEEDED entry for this file, unless it is used to resolve
368 references in a regular object. */
369 link_class
= DYN_DT_NEEDED
;
371 /* Tell the ELF linker that we don't want the output file to have a
372 DT_NEEDED entry for this file at all if the entry is from a file
373 with DYN_NO_ADD_NEEDED. */
374 if (needed
->by
!= NULL
375 && (bfd_elf_get_dyn_lib_class (needed
->by
) & DYN_NO_ADD_NEEDED
) != 0)
376 link_class
|= DYN_NO_NEEDED
| DYN_NO_ADD_NEEDED
;
378 bfd_elf_set_dyn_lib_class (abfd
, (enum dynamic_lib_link_class
) link_class
);
380 *link_info
.input_bfds_tail
= abfd
;
381 link_info
.input_bfds_tail
= &abfd
->link
.next
;
383 /* Add this file into the symbol table. */
384 if (! bfd_link_add_symbols (abfd
, &link_info
))
385 einfo (_("%F%P: %pB: error adding symbols: %E\n"), abfd
);
390 /* Search for a needed file in a path. */
393 ldelf_search_needed (const char *path
, struct dt_needed
*n
, int force
,
394 int is_linux
, int elfsize
)
397 const char *name
= n
->name
;
399 struct dt_needed needed
;
402 return ldelf_try_needed (n
, force
, is_linux
);
404 if (path
== NULL
|| *path
== '\0')
408 needed
.name
= n
->name
;
415 char *filename
, *sset
;
417 s
= strchr (path
, config
.rpath_separator
);
419 s
= path
+ strlen (path
);
421 #if HAVE_DOS_BASED_FILE_SYSTEM
422 /* Assume a match on the second char is part of drive specifier. */
423 else if (config
.rpath_separator
== ':'
427 s
= strchr (s
+ 1, config
.rpath_separator
);
429 s
= path
+ strlen (path
);
432 filename
= (char *) xmalloc (s
- path
+ len
+ 2);
437 memcpy (filename
, path
, s
- path
);
438 filename
[s
- path
] = '/';
439 sset
= filename
+ (s
- path
) + 1;
443 /* PR 20535: Support the same pseudo-environment variables that
444 are supported by ld.so. Namely, $ORIGIN, $LIB and $PLATFORM.
445 Since there can be more than one occurrence of these tokens in
446 the path we loop until no more are found. Since we might not
447 be able to substitute some of the tokens we maintain an offset
448 into the filename for where we should begin our scan. */
449 while ((var
= strchr (filename
+ offset
, '$')) != NULL
)
451 /* The ld.so manual page does not say, but I am going to assume that
452 these tokens are terminated by a directory separator character
453 (/) or the end of the string. There is also an implication that
454 $ORIGIN should only be used at the start of a path, but that is
457 The ld.so manual page also states that it allows ${ORIGIN},
458 ${LIB} and ${PLATFORM}, so these are supported as well.
460 FIXME: The code could be a lot cleverer about allocating space
461 for the processed string. */
462 char * end
= strchr (var
, '/');
463 const char *replacement
= NULL
;
465 char * freeme
= NULL
;
466 unsigned flen
= strlen (filename
);
469 /* Temporarily terminate the filename at the end of the token. */
477 if (strcmp (v
, "RIGIN") == 0 || strcmp (v
, "RIGIN}") == 0)
479 /* ORIGIN - replace with the full path to the directory
480 containing the program or shared object. */
481 if (needed
.by
== NULL
)
483 if (link_info
.output_bfd
== NULL
)
488 replacement
= bfd_get_filename (link_info
.output_bfd
);
491 replacement
= bfd_get_filename (needed
.by
);
497 if (replacement
[0] == '/')
498 freeme
= xstrdup (replacement
);
501 char * current_dir
= getpwd ();
503 freeme
= xmalloc (strlen (replacement
)
504 + strlen (current_dir
) + 2);
505 sprintf (freeme
, "%s/%s", current_dir
, replacement
);
508 replacement
= freeme
;
509 if ((slash
= strrchr (replacement
, '/')) != NULL
)
516 if (strcmp (v
, "IB") == 0 || strcmp (v
, "IB}") == 0)
518 /* LIB - replace with "lib" in 32-bit environments
519 and "lib64" in 64-bit environments. */
523 case 32: replacement
= "lib"; break;
524 case 64: replacement
= "lib64"; break;
532 /* Supporting $PLATFORM in a cross-hosted environment is not
533 possible. Supporting it in a native environment involves
534 loading the <sys/auxv.h> header file which loads the
535 system <elf.h> header file, which conflicts with the
536 "include/elf/mips.h" header file. */
544 char * filename2
= xmalloc (flen
+ strlen (replacement
));
548 sprintf (filename2
, "%.*s%s/%s",
549 (int)(var
- filename
), filename
,
550 replacement
, end
+ 1);
551 offset
= (var
- filename
) + 1 + strlen (replacement
);
555 sprintf (filename2
, "%.*s%s",
556 (int)(var
- filename
), filename
,
558 offset
= var
- filename
+ strlen (replacement
);
562 filename
= filename2
;
563 /* There is no need to restore the path separator (when
564 end != NULL) as we have replaced the entire string. */
569 /* We only issue an "unrecognised" message in verbose mode
570 as the $<foo> token might be a legitimate component of
571 a path name in the target's file system. */
572 info_msg (_("unrecognised or unsupported token "
573 "'%s' in search path\n"), var
);
575 /* Restore the path separator. */
578 /* PR 20784: Make sure that we resume the scan *after*
579 the token that we could not replace. */
580 offset
= (var
+ 1) - filename
;
586 needed
.name
= filename
;
588 if (ldelf_try_needed (&needed
, force
, is_linux
))
601 /* Prefix the sysroot to absolute paths in PATH, a string containing
602 paths separated by config.rpath_separator. If running on a DOS
603 file system, paths containing a drive spec won't have the sysroot
604 prefix added, unless the sysroot also specifies the same drive. */
607 ldelf_add_sysroot (const char *path
)
612 int dos_drive_sysroot
= HAS_DRIVE_SPEC (ld_sysroot
);
614 len
= strlen (ld_sysroot
);
615 for (extra
= 0, p
= path
; ; )
617 int dos_drive
= HAS_DRIVE_SPEC (p
);
621 if (IS_DIR_SEPARATOR (*p
)
623 || (dos_drive_sysroot
624 && ld_sysroot
[0] == p
[-2])))
626 if (dos_drive
&& dos_drive_sysroot
)
631 p
= strchr (p
, config
.rpath_separator
);
637 ret
= xmalloc (strlen (path
) + extra
+ 1);
639 for (q
= ret
, p
= path
; ; )
642 int dos_drive
= HAS_DRIVE_SPEC (p
);
649 if (IS_DIR_SEPARATOR (*p
)
651 || (dos_drive_sysroot
652 && ld_sysroot
[0] == p
[-2])))
654 if (dos_drive
&& dos_drive_sysroot
)
656 strcpy (q
, ld_sysroot
+ 2);
661 strcpy (q
, ld_sysroot
);
665 end
= strchr (p
, config
.rpath_separator
);
668 size_t n
= end
- p
+ 1;
683 /* Read the system search path the FreeBSD way rather than the Linux way. */
684 #ifdef HAVE_ELF_HINTS_H
685 #include <elf-hints.h>
687 #include "elf-hints-local.h"
691 ldelf_check_ld_elf_hints (const struct bfd_link_needed_list
*l
, int force
,
694 static bfd_boolean initialized
;
695 static const char *ld_elf_hints
;
696 struct dt_needed needed
;
703 tmppath
= concat (ld_sysroot
, _PATH_ELF_HINTS
, (const char *) NULL
);
704 f
= fopen (tmppath
, FOPEN_RB
);
708 struct elfhints_hdr hdr
;
710 if (fread (&hdr
, 1, sizeof (hdr
), f
) == sizeof (hdr
)
711 && hdr
.magic
== ELFHINTS_MAGIC
714 if (fseek (f
, hdr
.strtab
+ hdr
.dirlist
, SEEK_SET
) != -1)
718 b
= xmalloc (hdr
.dirlistlen
+ 1);
719 if (fread (b
, 1, hdr
.dirlistlen
+ 1, f
) ==
721 ld_elf_hints
= ldelf_add_sysroot (b
);
732 if (ld_elf_hints
== NULL
)
736 needed
.name
= l
->name
;
737 return ldelf_search_needed (ld_elf_hints
, &needed
, force
, FALSE
, elfsize
);
740 /* For a native linker, check the file /etc/ld.so.conf for directories
741 in which we may find shared libraries. /etc/ld.so.conf is really
742 only meaningful on Linux. */
744 struct ldelf_ld_so_conf
751 ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf
*, const char *);
754 ldelf_parse_ld_so_conf_include (struct ldelf_ld_so_conf
*info
,
755 const char *filename
,
763 if (pattern
[0] != '/')
765 char *p
= strrchr (filename
, '/');
766 size_t patlen
= strlen (pattern
) + 1;
768 newp
= xmalloc (p
- filename
+ 1 + patlen
);
769 memcpy (newp
, filename
, p
- filename
+ 1);
770 memcpy (newp
+ (p
- filename
+ 1), pattern
, patlen
);
775 if (glob (pattern
, 0, NULL
, &gl
) == 0)
779 for (i
= 0; i
< gl
.gl_pathc
; ++i
)
780 ldelf_parse_ld_so_conf (info
, gl
.gl_pathv
[i
]);
784 /* If we do not have glob, treat the pattern as a literal filename. */
785 ldelf_parse_ld_so_conf (info
, pattern
);
792 ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf
*info
, const char *filename
)
794 FILE *f
= fopen (filename
, FOPEN_RT
);
802 line
= xmalloc (linelen
);
807 /* Normally this would use getline(3), but we need to be portable. */
808 while ((q
= fgets (p
, linelen
- (p
- line
), f
)) != NULL
809 && strlen (q
) == linelen
- (p
- line
) - 1
810 && line
[linelen
- 2] != '\n')
812 line
= xrealloc (line
, 2 * linelen
);
813 p
= line
+ linelen
- 1;
817 if (q
== NULL
&& p
== line
)
820 p
= strchr (line
, '\n');
824 /* Because the file format does not know any form of quoting we
825 can search forward for the next '#' character and if found
826 make it terminating the line. */
827 p
= strchr (line
, '#');
831 /* Remove leading whitespace. NUL is no whitespace character. */
833 while (*p
== ' ' || *p
== '\f' || *p
== '\r' || *p
== '\t' || *p
== '\v')
836 /* If the line is blank it is ignored. */
840 if (CONST_STRNEQ (p
, "include") && (p
[7] == ' ' || p
[7] == '\t'))
846 while (*p
== ' ' || *p
== '\t')
854 while (*p
!= ' ' && *p
!= '\t' && *p
)
860 ldelf_parse_ld_so_conf_include (info
, filename
, dir
);
867 while (*p
&& *p
!= '=' && *p
!= ' ' && *p
!= '\t' && *p
!= '\f'
868 && *p
!= '\r' && *p
!= '\v')
871 while (p
!= dir
&& p
[-1] == '/')
873 if (info
->path
== NULL
)
875 info
->alloc
= p
- dir
+ 1 + 256;
876 info
->path
= xmalloc (info
->alloc
);
881 if (info
->len
+ 1 + (p
- dir
) >= info
->alloc
)
883 info
->alloc
+= p
- dir
+ 256;
884 info
->path
= xrealloc (info
->path
, info
->alloc
);
886 info
->path
[info
->len
++] = config
.rpath_separator
;
888 memcpy (info
->path
+ info
->len
, dir
, p
- dir
);
889 info
->len
+= p
- dir
;
890 info
->path
[info
->len
] = '\0';
900 ldelf_check_ld_so_conf (const struct bfd_link_needed_list
*l
, int force
,
901 int elfsize
, const char *prefix
)
903 static bfd_boolean initialized
;
904 static const char *ld_so_conf
;
905 struct dt_needed needed
;
910 struct ldelf_ld_so_conf info
;
913 info
.len
= info
.alloc
= 0;
914 tmppath
= concat (ld_sysroot
, prefix
, "/etc/ld.so.conf",
915 (const char *) NULL
);
916 if (!ldelf_parse_ld_so_conf (&info
, tmppath
))
919 tmppath
= concat (ld_sysroot
, "/etc/ld.so.conf",
920 (const char *) NULL
);
921 ldelf_parse_ld_so_conf (&info
, tmppath
);
927 ld_so_conf
= ldelf_add_sysroot (info
.path
);
933 if (ld_so_conf
== NULL
)
938 needed
.name
= l
->name
;
939 return ldelf_search_needed (ld_so_conf
, &needed
, force
, TRUE
, elfsize
);
942 /* See if an input file matches a DT_NEEDED entry by name. */
945 ldelf_check_needed (lang_input_statement_type
*s
)
949 /* Stop looking if we've found a loaded lib. */
950 if (global_found
!= NULL
951 && (bfd_elf_get_dyn_lib_class (global_found
->the_bfd
)
952 & DYN_AS_NEEDED
) == 0)
955 if (s
->filename
== NULL
|| s
->the_bfd
== NULL
)
958 /* Don't look for a second non-loaded as-needed lib. */
959 if (global_found
!= NULL
960 && (bfd_elf_get_dyn_lib_class (s
->the_bfd
) & DYN_AS_NEEDED
) != 0)
963 if (filename_cmp (s
->filename
, global_needed
->name
) == 0)
969 if (s
->flags
.search_dirs
)
971 const char *f
= strrchr (s
->filename
, '/');
973 && filename_cmp (f
+ 1, global_needed
->name
) == 0)
980 soname
= bfd_elf_get_dt_soname (s
->the_bfd
);
982 && filename_cmp (soname
, global_needed
->name
) == 0)
989 /* This is called after all the input files have been opened. */
992 ldelf_after_open (int use_libpath
, int native
, int is_linux
, int is_freebsd
,
993 int elfsize
, const char *prefix
)
995 struct bfd_link_needed_list
*needed
, *l
;
996 struct elf_link_hash_table
*htab
;
999 bfd
**save_input_bfd_tail
;
1001 after_open_default ();
1003 htab
= elf_hash_table (&link_info
);
1004 if (!is_elf_hash_table (htab
))
1007 if (command_line
.out_implib_filename
)
1009 unlink_if_ordinary (command_line
.out_implib_filename
);
1010 link_info
.out_implib_bfd
1011 = bfd_openw (command_line
.out_implib_filename
,
1012 bfd_get_target (link_info
.output_bfd
));
1014 if (link_info
.out_implib_bfd
== NULL
)
1016 einfo (_("%F%P: %s: can't open for writing: %E\n"),
1017 command_line
.out_implib_filename
);
1021 if (ldelf_emit_note_gnu_build_id
!= NULL
)
1023 /* Find an ELF input. */
1024 for (abfd
= link_info
.input_bfds
;
1025 abfd
!= (bfd
*) NULL
; abfd
= abfd
->link
.next
)
1026 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
1027 && bfd_count_sections (abfd
) != 0
1028 && !bfd_input_just_syms (abfd
))
1031 /* PR 10555: If there are no ELF input files do not try to
1032 create a .note.gnu-build-id section. */
1034 || !ldelf_setup_build_id (abfd
))
1036 free ((char *) ldelf_emit_note_gnu_build_id
);
1037 ldelf_emit_note_gnu_build_id
= NULL
;
1041 get_elf_backend_data (link_info
.output_bfd
)->setup_gnu_properties (&link_info
);
1043 /* Do not allow executable files to be used as inputs to the link. */
1044 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1046 if (!bfd_input_just_syms (abfd
)
1047 && elf_tdata (abfd
) != NULL
1048 && elf_tdata (abfd
)->elf_header
!= NULL
1049 /* FIXME: Maybe check for other non-supportable types as well ? */
1050 && elf_tdata (abfd
)->elf_header
->e_type
== ET_EXEC
)
1051 einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"),
1055 if (bfd_link_relocatable (&link_info
))
1057 if (link_info
.execstack
== !link_info
.noexecstack
)
1059 /* PR ld/16744: If "-z [no]execstack" has been specified on the
1060 command line and we are perfoming a relocatable link then no
1061 PT_GNU_STACK segment will be created and so the
1062 linkinfo.[no]execstack values set in _handle_option() will have no
1063 effect. Instead we create a .note.GNU-stack section in much the
1064 same way as the assembler does with its --[no]execstack option. */
1065 flagword flags
= SEC_READONLY
| (link_info
.execstack
? SEC_CODE
: 0);
1066 (void) bfd_make_section_with_flags (link_info
.input_bfds
,
1067 ".note.GNU-stack", flags
);
1072 if (!link_info
.traditional_format
)
1075 bfd_boolean warn_eh_frame
= FALSE
;
1078 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1082 if (bfd_input_just_syms (abfd
))
1085 for (s
= abfd
->sections
; s
&& type
< COMPACT_EH_HDR
; s
= s
->next
)
1087 const char *name
= bfd_section_name (s
);
1089 if (bfd_is_abs_section (s
->output_section
))
1091 if (CONST_STRNEQ (name
, ".eh_frame_entry"))
1092 type
= COMPACT_EH_HDR
;
1093 else if (strcmp (name
, ".eh_frame") == 0 && s
->size
> 8)
1094 type
= DWARF2_EH_HDR
;
1103 else if (seen_type
!= type
)
1105 einfo (_("%F%P: compact frame descriptions incompatible with"
1106 " DWARF2 .eh_frame from %pB\n"),
1107 type
== DWARF2_EH_HDR
? abfd
: elfbfd
);
1112 && (type
== COMPACT_EH_HDR
1113 || link_info
.eh_frame_hdr_type
!= 0))
1115 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
1118 warn_eh_frame
= TRUE
;
1122 if (seen_type
== COMPACT_EH_HDR
)
1123 link_info
.eh_frame_hdr_type
= COMPACT_EH_HDR
;
1127 const struct elf_backend_data
*bed
;
1129 bed
= get_elf_backend_data (elfbfd
);
1130 s
= bfd_make_section_with_flags (elfbfd
, ".eh_frame_hdr",
1131 bed
->dynamic_sec_flags
1134 && bfd_set_section_alignment (s
, 2))
1136 htab
->eh_info
.hdr_sec
= s
;
1137 warn_eh_frame
= FALSE
;
1141 einfo (_("%P: warning: cannot create .eh_frame_hdr section,"
1142 " --eh-frame-hdr ignored\n"));
1145 /* Get the list of files which appear in DT_NEEDED entries in
1146 dynamic objects included in the link (often there will be none).
1147 For each such file, we want to track down the corresponding
1148 library, and include the symbol table in the link. This is what
1149 the runtime dynamic linker will do. Tracking the files down here
1150 permits one dynamic object to include another without requiring
1151 special action by the person doing the link. Note that the
1152 needed list can actually grow while we are stepping through this
1154 save_input_bfd_tail
= link_info
.input_bfds_tail
;
1155 needed
= bfd_elf_get_needed_list (link_info
.output_bfd
, &link_info
);
1156 for (l
= needed
; l
!= NULL
; l
= l
->next
)
1158 struct bfd_link_needed_list
*ll
;
1159 struct dt_needed n
, nn
;
1162 /* If the lib that needs this one was --as-needed and wasn't
1163 found to be needed, then this lib isn't needed either. */
1165 && (bfd_elf_get_dyn_lib_class (l
->by
) & DYN_AS_NEEDED
) != 0)
1168 /* Skip the lib if --no-copy-dt-needed-entries and
1169 --allow-shlib-undefined is in effect. */
1171 && link_info
.unresolved_syms_in_shared_libs
== RM_IGNORE
1172 && (bfd_elf_get_dyn_lib_class (l
->by
) & DYN_NO_ADD_NEEDED
) != 0)
1175 /* If we've already seen this file, skip it. */
1176 for (ll
= needed
; ll
!= l
; ll
= ll
->next
)
1178 || (bfd_elf_get_dyn_lib_class (ll
->by
) & DYN_AS_NEEDED
) == 0)
1179 && strcmp (ll
->name
, l
->name
) == 0)
1184 /* See if this file was included in the link explicitly. */
1186 global_found
= NULL
;
1187 lang_for_each_input_file (ldelf_check_needed
);
1188 if (global_found
!= NULL
1189 && (bfd_elf_get_dyn_lib_class (global_found
->the_bfd
)
1190 & DYN_AS_NEEDED
) == 0)
1197 info_msg (_("%s needed by %pB\n"), l
->name
, l
->by
);
1199 /* As-needed libs specified on the command line (or linker script)
1200 take priority over libs found in search dirs. */
1201 if (global_found
!= NULL
)
1203 nn
.name
= global_found
->filename
;
1204 if (ldelf_try_needed (&nn
, TRUE
, is_linux
))
1208 /* We need to find this file and include the symbol table. We
1209 want to search for the file in the same way that the dynamic
1210 linker will search. That means that we want to use
1211 rpath_link, rpath, then the environment variable
1212 LD_LIBRARY_PATH (native only), then the DT_RPATH/DT_RUNPATH
1213 entries (native only), then the linker script LIB_SEARCH_DIRS.
1214 We do not search using the -L arguments.
1216 We search twice. The first time, we skip objects which may
1217 introduce version mismatches. The second time, we force
1218 their use. See ldelf_vercheck comment. */
1219 for (force
= 0; force
< 2; force
++)
1222 search_dirs_type
*search
;
1224 struct bfd_link_needed_list
*rp
;
1227 if (ldelf_search_needed (command_line
.rpath_link
, &n
, force
,
1233 path
= command_line
.rpath
;
1236 path
= ldelf_add_sysroot (path
);
1237 found
= ldelf_search_needed (path
, &n
, force
,
1239 free ((char *) path
);
1246 if (command_line
.rpath_link
== NULL
1247 && command_line
.rpath
== NULL
)
1249 path
= (const char *) getenv ("LD_RUN_PATH");
1251 && ldelf_search_needed (path
, &n
, force
,
1255 path
= (const char *) getenv ("LD_LIBRARY_PATH");
1257 && ldelf_search_needed (path
, &n
, force
,
1264 rp
= bfd_elf_get_runpath_list (link_info
.output_bfd
, &link_info
);
1265 for (; !found
&& rp
!= NULL
; rp
= rp
->next
)
1267 path
= ldelf_add_sysroot (rp
->name
);
1268 found
= (rp
->by
== l
->by
1269 && ldelf_search_needed (path
, &n
, force
,
1270 is_linux
, elfsize
));
1271 free ((char *) path
);
1277 && ldelf_check_ld_elf_hints (l
, force
, elfsize
))
1281 && ldelf_check_ld_so_conf (l
, force
, elfsize
, prefix
))
1285 len
= strlen (l
->name
);
1286 for (search
= search_head
; search
!= NULL
; search
= search
->next
)
1290 if (search
->cmdline
)
1292 filename
= (char *) xmalloc (strlen (search
->name
) + len
+ 2);
1293 sprintf (filename
, "%s/%s", search
->name
, l
->name
);
1295 if (ldelf_try_needed (&nn
, force
, is_linux
))
1306 einfo (_("%P: warning: %s, needed by %pB, not found "
1307 "(try using -rpath or -rpath-link)\n"),
1311 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1312 if (bfd_get_format (abfd
) == bfd_object
1313 && ((abfd
->flags
) & DYNAMIC
) != 0
1314 && bfd_get_flavour (abfd
) == bfd_target_elf_flavour
1315 && (elf_dyn_lib_class (abfd
) & (DYN_AS_NEEDED
| DYN_NO_NEEDED
)) == 0
1316 && elf_dt_name (abfd
) != NULL
)
1318 if (bfd_elf_add_dt_needed_tag (abfd
, &link_info
) < 0)
1319 einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n"));
1322 link_info
.input_bfds_tail
= save_input_bfd_tail
;
1323 *save_input_bfd_tail
= NULL
;
1325 if (link_info
.eh_frame_hdr_type
== COMPACT_EH_HDR
)
1326 if (!bfd_elf_parse_eh_frame_entries (NULL
, &link_info
))
1327 einfo (_("%F%P: failed to parse EH frame entries\n"));
1330 static bfd_size_type
1331 id_note_section_size (bfd
*abfd ATTRIBUTE_UNUSED
)
1333 const char *style
= ldelf_emit_note_gnu_build_id
;
1335 bfd_size_type build_id_size
;
1337 size
= offsetof (Elf_External_Note
, name
[sizeof "GNU"]);
1338 size
= (size
+ 3) & -(bfd_size_type
) 4;
1340 build_id_size
= compute_build_id_size (style
);
1342 size
+= build_id_size
;
1350 write_build_id (bfd
*abfd
)
1352 const struct elf_backend_data
*bed
= get_elf_backend_data (abfd
);
1353 struct elf_obj_tdata
*t
= elf_tdata (abfd
);
1356 Elf_Internal_Shdr
*i_shdr
;
1357 unsigned char *contents
, *id_bits
;
1360 Elf_External_Note
*e_note
;
1362 style
= t
->o
->build_id
.style
;
1363 asec
= t
->o
->build_id
.sec
;
1364 if (bfd_is_abs_section (asec
->output_section
))
1366 einfo (_("%P: warning: .note.gnu.build-id section discarded,"
1367 " --build-id ignored\n"));
1370 i_shdr
= &elf_section_data (asec
->output_section
)->this_hdr
;
1372 if (i_shdr
->contents
== NULL
)
1374 if (asec
->contents
== NULL
)
1375 asec
->contents
= (unsigned char *) xmalloc (asec
->size
);
1376 contents
= asec
->contents
;
1379 contents
= i_shdr
->contents
+ asec
->output_offset
;
1381 e_note
= (Elf_External_Note
*) contents
;
1382 size
= offsetof (Elf_External_Note
, name
[sizeof "GNU"]);
1383 size
= (size
+ 3) & -(bfd_size_type
) 4;
1384 id_bits
= contents
+ size
;
1385 size
= asec
->size
- size
;
1387 bfd_h_put_32 (abfd
, sizeof "GNU", &e_note
->namesz
);
1388 bfd_h_put_32 (abfd
, size
, &e_note
->descsz
);
1389 bfd_h_put_32 (abfd
, NT_GNU_BUILD_ID
, &e_note
->type
);
1390 memcpy (e_note
->name
, "GNU", sizeof "GNU");
1392 generate_build_id (abfd
, style
, bed
->s
->checksum_contents
, id_bits
, size
);
1394 position
= i_shdr
->sh_offset
+ asec
->output_offset
;
1396 return (bfd_seek (abfd
, position
, SEEK_SET
) == 0
1397 && bfd_bwrite (contents
, size
, abfd
) == size
);
1400 /* Make .note.gnu.build-id section, and set up elf_tdata->build_id. */
1403 ldelf_setup_build_id (bfd
*ibfd
)
1409 size
= id_note_section_size (ibfd
);
1412 einfo (_("%P: warning: unrecognized --build-id style ignored\n"));
1416 flags
= (SEC_ALLOC
| SEC_LOAD
| SEC_IN_MEMORY
1417 | SEC_LINKER_CREATED
| SEC_READONLY
| SEC_DATA
);
1418 s
= bfd_make_section_with_flags (ibfd
, ".note.gnu.build-id", flags
);
1419 if (s
!= NULL
&& bfd_set_section_alignment (s
, 2))
1421 struct elf_obj_tdata
*t
= elf_tdata (link_info
.output_bfd
);
1422 t
->o
->build_id
.after_write_object_contents
= &write_build_id
;
1423 t
->o
->build_id
.style
= ldelf_emit_note_gnu_build_id
;
1424 t
->o
->build_id
.sec
= s
;
1425 elf_section_type (s
) = SHT_NOTE
;
1430 einfo (_("%P: warning: cannot create .note.gnu.build-id section,"
1431 " --build-id ignored\n"));
1435 /* Look through an expression for an assignment statement. */
1438 ldelf_find_exp_assignment (etree_type
*exp
)
1440 bfd_boolean provide
= FALSE
;
1442 switch (exp
->type
.node_class
)
1445 case etree_provided
:
1449 /* We call record_link_assignment even if the symbol is defined.
1450 This is because if it is defined by a dynamic object, we
1451 actually want to use the value defined by the linker script,
1452 not the value from the dynamic object (because we are setting
1453 symbols like etext). If the symbol is defined by a regular
1454 object, then, as it happens, calling record_link_assignment
1456 if (strcmp (exp
->assign
.dst
, ".") != 0)
1458 if (!bfd_elf_record_link_assignment (link_info
.output_bfd
,
1460 exp
->assign
.dst
, provide
,
1461 exp
->assign
.hidden
))
1462 einfo (_("%F%P: failed to record assignment to %s: %E\n"),
1465 ldelf_find_exp_assignment (exp
->assign
.src
);
1469 ldelf_find_exp_assignment (exp
->binary
.lhs
);
1470 ldelf_find_exp_assignment (exp
->binary
.rhs
);
1474 ldelf_find_exp_assignment (exp
->trinary
.cond
);
1475 ldelf_find_exp_assignment (exp
->trinary
.lhs
);
1476 ldelf_find_exp_assignment (exp
->trinary
.rhs
);
1480 ldelf_find_exp_assignment (exp
->unary
.child
);
1488 /* This is called by the before_allocation routine via
1489 lang_for_each_statement. It locates any assignment statements, and
1490 tells the ELF backend about them, in case they are assignments to
1491 symbols which are referred to by dynamic objects. */
1494 ldelf_find_statement_assignment (lang_statement_union_type
*s
)
1496 if (s
->header
.type
== lang_assignment_statement_enum
)
1497 ldelf_find_exp_assignment (s
->assignment_statement
.exp
);
1500 /* Used by before_allocation and handle_option. */
1503 ldelf_append_to_separated_string (char **to
, char *op_arg
)
1506 *to
= xstrdup (op_arg
);
1509 size_t to_len
= strlen (*to
);
1510 size_t op_arg_len
= strlen (op_arg
);
1514 /* First see whether OPTARG is already in the path. */
1517 if (strncmp (op_arg
, cp
, op_arg_len
) == 0
1518 && (cp
[op_arg_len
] == 0
1519 || cp
[op_arg_len
] == config
.rpath_separator
))
1523 /* Not yet found. */
1524 cp
= strchr (cp
, config
.rpath_separator
);
1532 buf
= xmalloc (to_len
+ op_arg_len
+ 2);
1533 sprintf (buf
, "%s%c%s", *to
,
1534 config
.rpath_separator
, op_arg
);
1541 /* This is called after the sections have been attached to output
1542 sections, but before any sizes or addresses have been set. */
1545 ldelf_before_allocation (char *audit
, char *depaudit
,
1546 const char *default_interpreter_name
)
1551 struct bfd_link_hash_entry
*ehdr_start
= NULL
;
1552 unsigned char ehdr_start_save_type
= 0;
1553 char ehdr_start_save_u
[sizeof ehdr_start
->u
1554 - sizeof ehdr_start
->u
.def
.next
] = "";
1556 if (is_elf_hash_table (link_info
.hash
))
1558 _bfd_elf_tls_setup (link_info
.output_bfd
, &link_info
);
1560 /* Make __ehdr_start hidden if it has been referenced, to
1561 prevent the symbol from being dynamic. */
1562 if (!bfd_link_relocatable (&link_info
))
1564 struct elf_link_hash_table
*htab
= elf_hash_table (&link_info
);
1565 struct elf_link_hash_entry
*h
1566 = elf_link_hash_lookup (htab
, "__ehdr_start", FALSE
, FALSE
, TRUE
);
1568 /* Only adjust the export class if the symbol was referenced
1569 and not defined, otherwise leave it alone. */
1571 && (h
->root
.type
== bfd_link_hash_new
1572 || h
->root
.type
== bfd_link_hash_undefined
1573 || h
->root
.type
== bfd_link_hash_undefweak
1574 || h
->root
.type
== bfd_link_hash_common
))
1576 const struct elf_backend_data
*bed
;
1577 bed
= get_elf_backend_data (link_info
.output_bfd
);
1578 (*bed
->elf_backend_hide_symbol
) (&link_info
, h
, TRUE
);
1579 if (ELF_ST_VISIBILITY (h
->other
) != STV_INTERNAL
)
1580 h
->other
= (h
->other
& ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN
;
1581 /* Don't leave the symbol undefined. Undefined hidden
1582 symbols typically won't have dynamic relocations, but
1583 we most likely will need dynamic relocations for
1584 __ehdr_start if we are building a PIE or shared
1586 ehdr_start
= &h
->root
;
1587 ehdr_start_save_type
= ehdr_start
->type
;
1588 memcpy (ehdr_start_save_u
,
1589 (char *) &ehdr_start
->u
+ sizeof ehdr_start
->u
.def
.next
,
1590 sizeof ehdr_start_save_u
);
1591 ehdr_start
->type
= bfd_link_hash_defined
;
1592 ehdr_start
->u
.def
.section
= bfd_abs_section_ptr
;
1593 ehdr_start
->u
.def
.value
= 0;
1597 /* If we are going to make any variable assignments, we need to
1598 let the ELF backend know about them in case the variables are
1599 referred to by dynamic objects. */
1600 lang_for_each_statement (ldelf_find_statement_assignment
);
1603 /* Let the ELF backend work out the sizes of any sections required
1604 by dynamic linking. */
1605 rpath
= command_line
.rpath
;
1607 rpath
= (const char *) getenv ("LD_RUN_PATH");
1609 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1610 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
1612 const char *audit_libs
= elf_dt_audit (abfd
);
1614 /* If the input bfd contains an audit entry, we need to add it as
1615 a dep audit entry. */
1616 if (audit_libs
&& *audit_libs
!= '\0')
1618 char *cp
= xstrdup (audit_libs
);
1622 char *cp2
= strchr (cp
, config
.rpath_separator
);
1630 if (cp
!= NULL
&& *cp
!= '\0')
1631 ldelf_append_to_separated_string (&depaudit
, cp
);
1633 cp
= more
? ++cp2
: NULL
;
1639 if (! (bfd_elf_size_dynamic_sections
1640 (link_info
.output_bfd
, command_line
.soname
, rpath
,
1641 command_line
.filter_shlib
, audit
, depaudit
,
1642 (const char * const *) command_line
.auxiliary_filters
,
1643 &link_info
, &sinterp
)))
1644 einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1646 if (sinterp
!= NULL
)
1648 /* Let the user override the dynamic linker we are using. */
1649 if (command_line
.interpreter
!= NULL
)
1650 default_interpreter_name
= command_line
.interpreter
;
1651 if (default_interpreter_name
!= NULL
)
1653 sinterp
->contents
= (bfd_byte
*) default_interpreter_name
;
1654 sinterp
->size
= strlen ((char *) sinterp
->contents
) + 1;
1658 /* Look for any sections named .gnu.warning. As a GNU extensions,
1659 we treat such sections as containing warning messages. We print
1660 out the warning message, and then zero out the section size so
1661 that it does not get copied into the output file. */
1664 LANG_FOR_EACH_INPUT_STATEMENT (is
)
1670 if (is
->flags
.just_syms
)
1673 s
= bfd_get_section_by_name (is
->the_bfd
, ".gnu.warning");
1678 msg
= (char *) xmalloc ((size_t) (sz
+ 1));
1679 if (! bfd_get_section_contents (is
->the_bfd
, s
, msg
,
1681 einfo (_("%F%P: %pB: can't read contents of section .gnu.warning: %E\n"),
1684 (*link_info
.callbacks
->warning
) (&link_info
, msg
,
1685 (const char *) NULL
, is
->the_bfd
,
1686 (asection
*) NULL
, (bfd_vma
) 0);
1689 /* Clobber the section size, so that we don't waste space
1690 copying the warning into the output file. If we've already
1691 sized the output section, adjust its size. The adjustment
1692 is on rawsize because targets that size sections early will
1693 have called lang_reset_memory_regions after sizing. */
1694 if (s
->output_section
!= NULL
1695 && s
->output_section
->rawsize
>= s
->size
)
1696 s
->output_section
->rawsize
-= s
->size
;
1700 /* Also set SEC_EXCLUDE, so that local symbols defined in the
1701 warning section don't get copied to the output. */
1702 s
->flags
|= SEC_EXCLUDE
| SEC_KEEP
;
1706 before_allocation_default ();
1708 if (!bfd_elf_size_dynsym_hash_dynstr (link_info
.output_bfd
, &link_info
))
1709 einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1711 if (ehdr_start
!= NULL
)
1713 /* If we twiddled __ehdr_start to defined earlier, put it back
1715 ehdr_start
->type
= ehdr_start_save_type
;
1716 memcpy ((char *) &ehdr_start
->u
+ sizeof ehdr_start
->u
.def
.next
,
1718 sizeof ehdr_start_save_u
);
1721 /* Try to open a dynamic archive. This is where we know that ELF
1722 dynamic libraries have an extension of .so (or .sl on oddball systems
1726 ldelf_open_dynamic_archive (const char *arch
, search_dirs_type
*search
,
1727 lang_input_statement_type
*entry
)
1729 const char *filename
;
1732 bfd_boolean opened
= FALSE
;
1734 if (! entry
->flags
.maybe_archive
)
1737 filename
= entry
->filename
;
1738 len
= strlen (search
->name
) + strlen (filename
);
1739 if (entry
->flags
.full_name_provided
)
1742 string
= (char *) xmalloc (len
);
1743 sprintf (string
, "%s/%s", search
->name
, filename
);
1749 len
+= strlen (arch
) + sizeof "/lib.so";
1750 #ifdef EXTRA_SHLIB_EXTENSION
1751 xlen
= (strlen (EXTRA_SHLIB_EXTENSION
) > 3
1752 ? strlen (EXTRA_SHLIB_EXTENSION
) - 3
1755 string
= (char *) xmalloc (len
+ xlen
);
1756 sprintf (string
, "%s/lib%s%s.so", search
->name
, filename
, arch
);
1757 #ifdef EXTRA_SHLIB_EXTENSION
1758 /* Try the .so extension first. If that fails build a new filename
1759 using EXTRA_SHLIB_EXTENSION. */
1760 opened
= ldfile_try_open_bfd (string
, entry
);
1762 strcpy (string
+ len
- 4, EXTRA_SHLIB_EXTENSION
);
1766 if (!opened
&& !ldfile_try_open_bfd (string
, entry
))
1772 entry
->filename
= string
;
1774 /* We have found a dynamic object to include in the link. The ELF
1775 backend linker will create a DT_NEEDED entry in the .dynamic
1776 section naming this file. If this file includes a DT_SONAME
1777 entry, it will be used. Otherwise, the ELF linker will just use
1778 the name of the file. For an archive found by searching, like
1779 this one, the DT_NEEDED entry should consist of just the name of
1780 the file, without the path information used to find it. Note
1781 that we only need to do this if we have a dynamic object; an
1782 archive will never be referenced by a DT_NEEDED entry.
1784 FIXME: This approach--using bfd_elf_set_dt_needed_name--is not
1785 very pretty. I haven't been able to think of anything that is
1787 if (bfd_check_format (entry
->the_bfd
, bfd_object
)
1788 && (entry
->the_bfd
->flags
& DYNAMIC
) != 0)
1790 ASSERT (entry
->flags
.maybe_archive
&& entry
->flags
.search_dirs
);
1792 /* Rather than duplicating the logic above. Just use the
1793 filename we recorded earlier. */
1795 if (!entry
->flags
.full_name_provided
)
1796 filename
= lbasename (entry
->filename
);
1797 bfd_elf_set_dt_needed_name (entry
->the_bfd
, filename
);
1803 /* A variant of lang_output_section_find used by place_orphan. */
1805 static lang_output_section_statement_type
*
1806 output_rel_find (int isdyn
, int rela
)
1808 lang_output_section_statement_type
*lookup
;
1809 lang_output_section_statement_type
*last
= NULL
;
1810 lang_output_section_statement_type
*last_alloc
= NULL
;
1811 lang_output_section_statement_type
*last_ro_alloc
= NULL
;
1812 lang_output_section_statement_type
*last_rel
= NULL
;
1813 lang_output_section_statement_type
*last_rel_alloc
= NULL
;
1815 for (lookup
= (void *) lang_os_list
.head
;
1817 lookup
= lookup
->next
)
1819 if (lookup
->constraint
>= 0
1820 && CONST_STRNEQ (lookup
->name
, ".rel"))
1822 int lookrela
= lookup
->name
[4] == 'a';
1824 /* .rel.dyn must come before all other reloc sections, to suit
1829 /* Don't place after .rel.plt as doing so results in wrong
1831 if (strcmp (".plt", lookup
->name
+ 4 + lookrela
) == 0)
1834 if (rela
== lookrela
|| last_rel
== NULL
)
1836 if ((rela
== lookrela
|| last_rel_alloc
== NULL
)
1837 && lookup
->bfd_section
!= NULL
1838 && (lookup
->bfd_section
->flags
& SEC_ALLOC
) != 0)
1839 last_rel_alloc
= lookup
;
1843 if (lookup
->bfd_section
!= NULL
1844 && (lookup
->bfd_section
->flags
& SEC_ALLOC
) != 0)
1846 last_alloc
= lookup
;
1847 if ((lookup
->bfd_section
->flags
& SEC_READONLY
) != 0)
1848 last_ro_alloc
= lookup
;
1853 return last_rel_alloc
;
1859 return last_ro_alloc
;
1867 /* Return whether IN is suitable to be part of OUT. */
1870 elf_orphan_compatible (asection
*in
, asection
*out
)
1872 /* Non-zero sh_info implies a section with SHF_INFO_LINK with
1873 unknown semantics for the generic linker, or a SHT_REL/SHT_RELA
1874 section where sh_info specifies a symbol table. (We won't see
1875 SHT_GROUP, SHT_SYMTAB or SHT_DYNSYM sections here.) We clearly
1876 can't merge SHT_REL/SHT_RELA using differing symbol tables, and
1877 shouldn't merge sections with differing unknown semantics. */
1878 if (elf_section_data (out
)->this_hdr
.sh_info
1879 != elf_section_data (in
)->this_hdr
.sh_info
)
1881 /* We can't merge with a member of an output section group or merge
1882 two sections with differing SHF_EXCLUDE or other processor and OS
1883 specific flags when doing a relocatable link. */
1884 if (bfd_link_relocatable (&link_info
)
1885 && (elf_next_in_group (out
) != NULL
1886 || ((elf_section_flags (out
) ^ elf_section_flags (in
))
1887 & (SHF_MASKPROC
| SHF_MASKOS
)) != 0))
1889 return _bfd_elf_match_sections_by_type (link_info
.output_bfd
, out
,
1893 /* Place an orphan section. We use this to put random SHF_ALLOC
1894 sections in the right segment. */
1896 lang_output_section_statement_type
*
1897 ldelf_place_orphan (asection
*s
, const char *secname
, int constraint
)
1899 static struct orphan_save hold
[] =
1902 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_CODE
,
1905 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
1908 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
| SEC_THREAD_LOCAL
,
1911 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
,
1917 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
1920 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
1923 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
| SEC_SMALL_DATA
,
1929 enum orphan_save_index
1941 static int orphan_init_done
= 0;
1942 struct orphan_save
*place
;
1943 lang_output_section_statement_type
*after
;
1944 lang_output_section_statement_type
*os
;
1945 lang_output_section_statement_type
*match_by_name
= NULL
;
1947 int elfinput
= s
->owner
->xvec
->flavour
== bfd_target_elf_flavour
;
1948 int elfoutput
= link_info
.output_bfd
->xvec
->flavour
== bfd_target_elf_flavour
;
1949 unsigned int sh_type
= elfinput
? elf_section_type (s
) : SHT_NULL
;
1953 if (!bfd_link_relocatable (&link_info
)
1954 && link_info
.combreloc
1955 && (s
->flags
& SEC_ALLOC
))
1961 secname
= ".rela.dyn";
1965 secname
= ".rel.dyn";
1971 else if (CONST_STRNEQ (secname
, ".rel"))
1973 secname
= secname
[4] == 'a' ? ".rela.dyn" : ".rel.dyn";
1978 if (!bfd_link_relocatable (&link_info
)
1981 && (s
->flags
& SEC_ALLOC
) != 0
1982 && (elf_tdata (s
->owner
)->has_gnu_osabi
& elf_gnu_osabi_mbind
) != 0
1983 && (elf_section_flags (s
) & SHF_GNU_MBIND
) != 0)
1985 /* Find the output mbind section with the same type, attributes
1986 and sh_info field. */
1987 for (os
= (void *) lang_os_list
.head
;
1990 if (os
->bfd_section
!= NULL
1991 && !bfd_is_abs_section (os
->bfd_section
)
1992 && (elf_section_flags (os
->bfd_section
) & SHF_GNU_MBIND
) != 0
1993 && ((s
->flags
& (SEC_ALLOC
1998 == (os
->bfd_section
->flags
& (SEC_ALLOC
2003 && (elf_section_data (os
->bfd_section
)->this_hdr
.sh_info
2004 == elf_section_data (s
)->this_hdr
.sh_info
))
2006 lang_add_section (&os
->children
, s
, NULL
, os
);
2010 /* Create the output mbind section with the ".mbind." prefix
2012 if ((s
->flags
& (SEC_LOAD
| SEC_HAS_CONTENTS
)) == 0)
2013 secname
= ".mbind.bss";
2014 else if ((s
->flags
& SEC_READONLY
) == 0)
2015 secname
= ".mbind.data";
2016 else if ((s
->flags
& SEC_CODE
) == 0)
2017 secname
= ".mbind.rodata";
2019 secname
= ".mbind.text";
2020 elf_tdata (link_info
.output_bfd
)->has_gnu_osabi
|= elf_gnu_osabi_mbind
;
2023 /* Look through the script to see where to place this section. The
2024 script includes entries added by previous lang_insert_orphan
2025 calls, so this loop puts multiple compatible orphans of the same
2026 name into a single output section. */
2027 if (constraint
== 0)
2028 for (os
= lang_output_section_find (secname
);
2030 os
= next_matching_output_section_statement (os
, 0))
2032 /* If we don't match an existing output section, tell
2033 lang_insert_orphan to create a new output section. */
2034 constraint
= SPECIAL
;
2036 /* Check to see if we already have an output section statement
2037 with this name, and its bfd section has compatible flags.
2038 If the section already exists but does not have any flags
2039 set, then it has been created by the linker, possibly as a
2040 result of a --section-start command line switch. */
2041 if (os
->bfd_section
!= NULL
2042 && (os
->bfd_section
->flags
== 0
2043 || (((s
->flags
^ os
->bfd_section
->flags
)
2044 & (SEC_LOAD
| SEC_ALLOC
)) == 0
2047 || elf_orphan_compatible (s
, os
->bfd_section
)))))
2049 lang_add_section (&os
->children
, s
, NULL
, os
);
2053 /* Save unused output sections in case we can match them
2054 against orphans later. */
2055 if (os
->bfd_section
== NULL
)
2059 /* If we didn't match an active output section, see if we matched an
2060 unused one and use that. */
2063 lang_add_section (&match_by_name
->children
, s
, NULL
, match_by_name
);
2064 return match_by_name
;
2067 if (!orphan_init_done
)
2069 struct orphan_save
*ho
;
2071 for (ho
= hold
; ho
< hold
+ sizeof (hold
) / sizeof (hold
[0]); ++ho
)
2072 if (ho
->name
!= NULL
)
2074 ho
->os
= lang_output_section_find (ho
->name
);
2075 if (ho
->os
!= NULL
&& ho
->os
->flags
== 0)
2076 ho
->os
->flags
= ho
->flags
;
2078 orphan_init_done
= 1;
2081 /* If this is a final link, then always put .gnu.warning.SYMBOL
2082 sections into the .text section to get them out of the way. */
2083 if (bfd_link_executable (&link_info
)
2084 && CONST_STRNEQ (s
->name
, ".gnu.warning.")
2085 && hold
[orphan_text
].os
!= NULL
)
2087 os
= hold
[orphan_text
].os
;
2088 lang_add_section (&os
->children
, s
, NULL
, os
);
2093 if (!bfd_link_relocatable (&link_info
))
2096 while ((nexts
= bfd_get_next_section_by_name (nexts
->owner
, nexts
))
2098 if (nexts
->output_section
== NULL
2099 && (nexts
->flags
& SEC_EXCLUDE
) == 0
2100 && ((nexts
->flags
^ flags
) & (SEC_LOAD
| SEC_ALLOC
)) == 0
2101 && (nexts
->owner
->flags
& DYNAMIC
) == 0
2102 && !bfd_input_just_syms (nexts
->owner
)
2103 && _bfd_elf_match_sections_by_type (nexts
->owner
, nexts
,
2105 flags
= (((flags
^ SEC_READONLY
)
2106 | (nexts
->flags
^ SEC_READONLY
))
2110 /* Decide which segment the section should go in based on the
2111 section name and section flags. We put loadable .note sections
2112 right after the .interp section, so that the PT_NOTE segment is
2113 stored right after the program headers where the OS can read it
2114 in the first page. */
2117 if ((flags
& (SEC_ALLOC
| SEC_DEBUGGING
)) == 0)
2118 place
= &hold
[orphan_nonalloc
];
2119 else if ((flags
& SEC_ALLOC
) == 0)
2121 else if ((flags
& SEC_LOAD
) != 0
2123 ? sh_type
== SHT_NOTE
2124 : CONST_STRNEQ (secname
, ".note")))
2125 place
= &hold
[orphan_interp
];
2126 else if ((flags
& (SEC_LOAD
| SEC_HAS_CONTENTS
| SEC_THREAD_LOCAL
)) == 0)
2127 place
= &hold
[orphan_bss
];
2128 else if ((flags
& SEC_SMALL_DATA
) != 0)
2129 place
= &hold
[orphan_sdata
];
2130 else if ((flags
& SEC_THREAD_LOCAL
) != 0)
2131 place
= &hold
[orphan_tdata
];
2132 else if ((flags
& SEC_READONLY
) == 0)
2133 place
= &hold
[orphan_data
];
2134 else if ((flags
& SEC_LOAD
) != 0
2136 ? sh_type
== SHT_RELA
|| sh_type
== SHT_REL
2137 : CONST_STRNEQ (secname
, ".rel")))
2138 place
= &hold
[orphan_rel
];
2139 else if ((flags
& SEC_CODE
) == 0)
2140 place
= &hold
[orphan_rodata
];
2142 place
= &hold
[orphan_text
];
2147 if (place
->os
== NULL
)
2149 if (place
->name
!= NULL
)
2150 place
->os
= lang_output_section_find (place
->name
);
2153 int rela
= elfinput
? sh_type
== SHT_RELA
: secname
[4] == 'a';
2154 place
->os
= output_rel_find (isdyn
, rela
);
2160 = lang_output_section_find_by_flags (s
, flags
, &place
->os
,
2161 _bfd_elf_match_sections_by_type
);
2163 /* *ABS* is always the first output section statement. */
2164 after
= (void *) lang_os_list
.head
;
2167 return lang_insert_orphan (s
, secname
, constraint
, after
, place
, NULL
, NULL
);
2171 ldelf_before_place_orphans (void)
2175 for (abfd
= link_info
.input_bfds
;
2176 abfd
!= (bfd
*) NULL
; abfd
= abfd
->link
.next
)
2177 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
2178 && bfd_count_sections (abfd
) != 0
2179 && !bfd_input_just_syms (abfd
))
2182 for (isec
= abfd
->sections
; isec
!= NULL
; isec
= isec
->next
)
2184 /* Discard a section if any of its linked-to section has
2186 asection
*linked_to_sec
;
2187 for (linked_to_sec
= elf_linked_to_section (isec
);
2188 linked_to_sec
!= NULL
;
2189 linked_to_sec
= elf_linked_to_section (linked_to_sec
))
2190 if (discarded_section (linked_to_sec
))
2192 isec
->output_section
= bfd_abs_section_ptr
;
2193 isec
->flags
|= SEC_EXCLUDE
;