1 /* ELF emulation code for targets using elf.em.
2 Copyright (C) 1991-2021 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 bool 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 (startswith (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 bool 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 (startswith (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 bool 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
->root
))
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 (abfd
->xvec
->flavour
== bfd_target_elf_flavour
1047 && !bfd_input_just_syms (abfd
)
1048 && elf_tdata (abfd
) != NULL
1049 && elf_tdata (abfd
)->elf_header
!= NULL
1050 /* FIXME: Maybe check for other non-supportable types as well ? */
1051 && (elf_tdata (abfd
)->elf_header
->e_type
== ET_EXEC
1052 || (elf_tdata (abfd
)->elf_header
->e_type
== ET_DYN
1053 && elf_tdata (abfd
)->is_pie
)))
1054 einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"),
1058 if (bfd_link_relocatable (&link_info
))
1060 if (link_info
.execstack
== !link_info
.noexecstack
)
1062 /* PR ld/16744: If "-z [no]execstack" has been specified on the
1063 command line and we are perfoming a relocatable link then no
1064 PT_GNU_STACK segment will be created and so the
1065 linkinfo.[no]execstack values set in _handle_option() will have no
1066 effect. Instead we create a .note.GNU-stack section in much the
1067 same way as the assembler does with its --[no]execstack option. */
1068 flagword flags
= SEC_READONLY
| (link_info
.execstack
? SEC_CODE
: 0);
1069 (void) bfd_make_section_with_flags (link_info
.input_bfds
,
1070 ".note.GNU-stack", flags
);
1075 if (!link_info
.traditional_format
)
1078 bool warn_eh_frame
= false;
1081 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1085 if (bfd_input_just_syms (abfd
))
1088 for (s
= abfd
->sections
; s
&& type
< COMPACT_EH_HDR
; s
= s
->next
)
1090 const char *name
= bfd_section_name (s
);
1092 if (bfd_is_abs_section (s
->output_section
))
1094 if (startswith (name
, ".eh_frame_entry"))
1095 type
= COMPACT_EH_HDR
;
1096 else if (strcmp (name
, ".eh_frame") == 0 && s
->size
> 8)
1097 type
= DWARF2_EH_HDR
;
1106 else if (seen_type
!= type
)
1108 einfo (_("%F%P: compact frame descriptions incompatible with"
1109 " DWARF2 .eh_frame from %pB\n"),
1110 type
== DWARF2_EH_HDR
? abfd
: elfbfd
);
1115 && (type
== COMPACT_EH_HDR
1116 || link_info
.eh_frame_hdr_type
!= 0))
1118 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
1121 warn_eh_frame
= true;
1125 if (seen_type
== COMPACT_EH_HDR
)
1126 link_info
.eh_frame_hdr_type
= COMPACT_EH_HDR
;
1130 const struct elf_backend_data
*bed
;
1132 bed
= get_elf_backend_data (elfbfd
);
1133 s
= bfd_make_section_with_flags (elfbfd
, ".eh_frame_hdr",
1134 bed
->dynamic_sec_flags
1137 && bfd_set_section_alignment (s
, 2))
1139 htab
->eh_info
.hdr_sec
= s
;
1140 warn_eh_frame
= false;
1144 einfo (_("%P: warning: cannot create .eh_frame_hdr section,"
1145 " --eh-frame-hdr ignored\n"));
1148 /* Get the list of files which appear in DT_NEEDED entries in
1149 dynamic objects included in the link (often there will be none).
1150 For each such file, we want to track down the corresponding
1151 library, and include the symbol table in the link. This is what
1152 the runtime dynamic linker will do. Tracking the files down here
1153 permits one dynamic object to include another without requiring
1154 special action by the person doing the link. Note that the
1155 needed list can actually grow while we are stepping through this
1157 save_input_bfd_tail
= link_info
.input_bfds_tail
;
1158 needed
= bfd_elf_get_needed_list (link_info
.output_bfd
, &link_info
);
1159 for (l
= needed
; l
!= NULL
; l
= l
->next
)
1161 struct bfd_link_needed_list
*ll
;
1162 struct dt_needed n
, nn
;
1165 /* If the lib that needs this one was --as-needed and wasn't
1166 found to be needed, then this lib isn't needed either. */
1168 && (bfd_elf_get_dyn_lib_class (l
->by
) & DYN_AS_NEEDED
) != 0)
1171 /* Skip the lib if --no-copy-dt-needed-entries and
1172 --allow-shlib-undefined is in effect. */
1174 && link_info
.unresolved_syms_in_shared_libs
== RM_IGNORE
1175 && (bfd_elf_get_dyn_lib_class (l
->by
) & DYN_NO_ADD_NEEDED
) != 0)
1178 /* If we've already seen this file, skip it. */
1179 for (ll
= needed
; ll
!= l
; ll
= ll
->next
)
1181 || (bfd_elf_get_dyn_lib_class (ll
->by
) & DYN_AS_NEEDED
) == 0)
1182 && strcmp (ll
->name
, l
->name
) == 0)
1187 /* See if this file was included in the link explicitly. */
1189 global_found
= NULL
;
1190 lang_for_each_input_file (ldelf_check_needed
);
1191 if (global_found
!= NULL
1192 && (bfd_elf_get_dyn_lib_class (global_found
->the_bfd
)
1193 & DYN_AS_NEEDED
) == 0)
1200 info_msg (_("%s needed by %pB\n"), l
->name
, l
->by
);
1202 /* As-needed libs specified on the command line (or linker script)
1203 take priority over libs found in search dirs. */
1204 if (global_found
!= NULL
)
1206 nn
.name
= global_found
->filename
;
1207 if (ldelf_try_needed (&nn
, true, is_linux
))
1211 /* We need to find this file and include the symbol table. We
1212 want to search for the file in the same way that the dynamic
1213 linker will search. That means that we want to use
1214 rpath_link, rpath, then the environment variable
1215 LD_LIBRARY_PATH (native only), then the DT_RPATH/DT_RUNPATH
1216 entries (native only), then the linker script LIB_SEARCH_DIRS.
1217 We do not search using the -L arguments.
1219 We search twice. The first time, we skip objects which may
1220 introduce version mismatches. The second time, we force
1221 their use. See ldelf_vercheck comment. */
1222 for (force
= 0; force
< 2; force
++)
1225 search_dirs_type
*search
;
1227 struct bfd_link_needed_list
*rp
;
1230 if (ldelf_search_needed (command_line
.rpath_link
, &n
, force
,
1236 path
= command_line
.rpath
;
1239 path
= ldelf_add_sysroot (path
);
1240 found
= ldelf_search_needed (path
, &n
, force
,
1242 free ((char *) path
);
1249 if (command_line
.rpath_link
== NULL
1250 && command_line
.rpath
== NULL
)
1252 path
= (const char *) getenv ("LD_RUN_PATH");
1254 && ldelf_search_needed (path
, &n
, force
,
1258 path
= (const char *) getenv ("LD_LIBRARY_PATH");
1260 && ldelf_search_needed (path
, &n
, force
,
1267 rp
= bfd_elf_get_runpath_list (link_info
.output_bfd
, &link_info
);
1268 for (; !found
&& rp
!= NULL
; rp
= rp
->next
)
1270 path
= ldelf_add_sysroot (rp
->name
);
1271 found
= (rp
->by
== l
->by
1272 && ldelf_search_needed (path
, &n
, force
,
1273 is_linux
, elfsize
));
1274 free ((char *) path
);
1280 && ldelf_check_ld_elf_hints (l
, force
, elfsize
))
1284 && ldelf_check_ld_so_conf (l
, force
, elfsize
, prefix
))
1288 len
= strlen (l
->name
);
1289 for (search
= search_head
; search
!= NULL
; search
= search
->next
)
1293 if (search
->cmdline
)
1295 filename
= (char *) xmalloc (strlen (search
->name
) + len
+ 2);
1296 sprintf (filename
, "%s/%s", search
->name
, l
->name
);
1298 if (ldelf_try_needed (&nn
, force
, is_linux
))
1309 einfo (_("%P: warning: %s, needed by %pB, not found "
1310 "(try using -rpath or -rpath-link)\n"),
1314 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1315 if (bfd_get_format (abfd
) == bfd_object
1316 && ((abfd
->flags
) & DYNAMIC
) != 0
1317 && bfd_get_flavour (abfd
) == bfd_target_elf_flavour
1318 && (elf_dyn_lib_class (abfd
) & (DYN_AS_NEEDED
| DYN_NO_NEEDED
)) == 0
1319 && elf_dt_name (abfd
) != NULL
)
1321 if (bfd_elf_add_dt_needed_tag (abfd
, &link_info
) < 0)
1322 einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n"));
1325 link_info
.input_bfds_tail
= save_input_bfd_tail
;
1326 *save_input_bfd_tail
= NULL
;
1328 if (link_info
.eh_frame_hdr_type
== COMPACT_EH_HDR
)
1329 if (!bfd_elf_parse_eh_frame_entries (NULL
, &link_info
))
1330 einfo (_("%F%P: failed to parse EH frame entries\n"));
1333 static bfd_size_type
1334 id_note_section_size (bfd
*abfd ATTRIBUTE_UNUSED
)
1336 const char *style
= ldelf_emit_note_gnu_build_id
;
1338 bfd_size_type build_id_size
;
1340 size
= offsetof (Elf_External_Note
, name
[sizeof "GNU"]);
1341 size
= (size
+ 3) & -(bfd_size_type
) 4;
1343 build_id_size
= compute_build_id_size (style
);
1345 size
+= build_id_size
;
1353 write_build_id (bfd
*abfd
)
1355 const struct elf_backend_data
*bed
= get_elf_backend_data (abfd
);
1356 struct elf_obj_tdata
*t
= elf_tdata (abfd
);
1359 Elf_Internal_Shdr
*i_shdr
;
1360 unsigned char *contents
, *id_bits
;
1363 Elf_External_Note
*e_note
;
1365 style
= t
->o
->build_id
.style
;
1366 asec
= t
->o
->build_id
.sec
;
1367 if (bfd_is_abs_section (asec
->output_section
))
1369 einfo (_("%P: warning: .note.gnu.build-id section discarded,"
1370 " --build-id ignored\n"));
1373 i_shdr
= &elf_section_data (asec
->output_section
)->this_hdr
;
1375 if (i_shdr
->contents
== NULL
)
1377 if (asec
->contents
== NULL
)
1378 asec
->contents
= (unsigned char *) xmalloc (asec
->size
);
1379 contents
= asec
->contents
;
1382 contents
= i_shdr
->contents
+ asec
->output_offset
;
1384 e_note
= (Elf_External_Note
*) contents
;
1385 size
= offsetof (Elf_External_Note
, name
[sizeof "GNU"]);
1386 size
= (size
+ 3) & -(bfd_size_type
) 4;
1387 id_bits
= contents
+ size
;
1388 size
= asec
->size
- size
;
1390 bfd_h_put_32 (abfd
, sizeof "GNU", &e_note
->namesz
);
1391 bfd_h_put_32 (abfd
, size
, &e_note
->descsz
);
1392 bfd_h_put_32 (abfd
, NT_GNU_BUILD_ID
, &e_note
->type
);
1393 memcpy (e_note
->name
, "GNU", sizeof "GNU");
1395 generate_build_id (abfd
, style
, bed
->s
->checksum_contents
, id_bits
, size
);
1397 position
= i_shdr
->sh_offset
+ asec
->output_offset
;
1399 return (bfd_seek (abfd
, position
, SEEK_SET
) == 0
1400 && bfd_bwrite (contents
, size
, abfd
) == size
);
1403 /* Make .note.gnu.build-id section, and set up elf_tdata->build_id. */
1406 ldelf_setup_build_id (bfd
*ibfd
)
1412 size
= id_note_section_size (ibfd
);
1415 einfo (_("%P: warning: unrecognized --build-id style ignored\n"));
1419 flags
= (SEC_ALLOC
| SEC_LOAD
| SEC_IN_MEMORY
1420 | SEC_LINKER_CREATED
| SEC_READONLY
| SEC_DATA
);
1421 s
= bfd_make_section_with_flags (ibfd
, ".note.gnu.build-id", flags
);
1422 if (s
!= NULL
&& bfd_set_section_alignment (s
, 2))
1424 struct elf_obj_tdata
*t
= elf_tdata (link_info
.output_bfd
);
1425 t
->o
->build_id
.after_write_object_contents
= &write_build_id
;
1426 t
->o
->build_id
.style
= ldelf_emit_note_gnu_build_id
;
1427 t
->o
->build_id
.sec
= s
;
1428 elf_section_type (s
) = SHT_NOTE
;
1433 einfo (_("%P: warning: cannot create .note.gnu.build-id section,"
1434 " --build-id ignored\n"));
1438 /* Look through an expression for an assignment statement. */
1441 ldelf_find_exp_assignment (etree_type
*exp
)
1443 bool provide
= false;
1445 switch (exp
->type
.node_class
)
1448 case etree_provided
:
1452 /* We call record_link_assignment even if the symbol is defined.
1453 This is because if it is defined by a dynamic object, we
1454 actually want to use the value defined by the linker script,
1455 not the value from the dynamic object (because we are setting
1456 symbols like etext). If the symbol is defined by a regular
1457 object, then, as it happens, calling record_link_assignment
1459 if (strcmp (exp
->assign
.dst
, ".") != 0)
1461 if (!bfd_elf_record_link_assignment (link_info
.output_bfd
,
1463 exp
->assign
.dst
, provide
,
1464 exp
->assign
.hidden
))
1465 einfo (_("%F%P: failed to record assignment to %s: %E\n"),
1468 ldelf_find_exp_assignment (exp
->assign
.src
);
1472 ldelf_find_exp_assignment (exp
->binary
.lhs
);
1473 ldelf_find_exp_assignment (exp
->binary
.rhs
);
1477 ldelf_find_exp_assignment (exp
->trinary
.cond
);
1478 ldelf_find_exp_assignment (exp
->trinary
.lhs
);
1479 ldelf_find_exp_assignment (exp
->trinary
.rhs
);
1483 ldelf_find_exp_assignment (exp
->unary
.child
);
1491 /* This is called by the before_allocation routine via
1492 lang_for_each_statement. It locates any assignment statements, and
1493 tells the ELF backend about them, in case they are assignments to
1494 symbols which are referred to by dynamic objects. */
1497 ldelf_find_statement_assignment (lang_statement_union_type
*s
)
1499 if (s
->header
.type
== lang_assignment_statement_enum
)
1500 ldelf_find_exp_assignment (s
->assignment_statement
.exp
);
1503 /* Used by before_allocation and handle_option. */
1506 ldelf_append_to_separated_string (char **to
, char *op_arg
)
1509 *to
= xstrdup (op_arg
);
1512 size_t to_len
= strlen (*to
);
1513 size_t op_arg_len
= strlen (op_arg
);
1517 /* First see whether OPTARG is already in the path. */
1520 if (strncmp (op_arg
, cp
, op_arg_len
) == 0
1521 && (cp
[op_arg_len
] == 0
1522 || cp
[op_arg_len
] == config
.rpath_separator
))
1526 /* Not yet found. */
1527 cp
= strchr (cp
, config
.rpath_separator
);
1535 buf
= xmalloc (to_len
+ op_arg_len
+ 2);
1536 sprintf (buf
, "%s%c%s", *to
,
1537 config
.rpath_separator
, op_arg
);
1544 /* This is called after the sections have been attached to output
1545 sections, but before any sizes or addresses have been set. */
1548 ldelf_before_allocation (char *audit
, char *depaudit
,
1549 const char *default_interpreter_name
)
1554 struct bfd_link_hash_entry
*ehdr_start
= NULL
;
1555 unsigned char ehdr_start_save_type
= 0;
1556 char ehdr_start_save_u
[sizeof ehdr_start
->u
1557 - sizeof ehdr_start
->u
.def
.next
] = "";
1559 if (is_elf_hash_table (link_info
.hash
))
1561 _bfd_elf_tls_setup (link_info
.output_bfd
, &link_info
);
1563 /* Make __ehdr_start hidden if it has been referenced, to
1564 prevent the symbol from being dynamic. */
1565 if (!bfd_link_relocatable (&link_info
))
1567 struct elf_link_hash_table
*htab
= elf_hash_table (&link_info
);
1568 struct elf_link_hash_entry
*h
1569 = elf_link_hash_lookup (htab
, "__ehdr_start", false, false, true);
1571 /* Only adjust the export class if the symbol was referenced
1572 and not defined, otherwise leave it alone. */
1574 && (h
->root
.type
== bfd_link_hash_new
1575 || h
->root
.type
== bfd_link_hash_undefined
1576 || h
->root
.type
== bfd_link_hash_undefweak
1577 || h
->root
.type
== bfd_link_hash_common
))
1579 const struct elf_backend_data
*bed
;
1580 bed
= get_elf_backend_data (link_info
.output_bfd
);
1581 (*bed
->elf_backend_hide_symbol
) (&link_info
, h
, true);
1582 if (ELF_ST_VISIBILITY (h
->other
) != STV_INTERNAL
)
1583 h
->other
= (h
->other
& ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN
;
1584 /* Don't leave the symbol undefined. Undefined hidden
1585 symbols typically won't have dynamic relocations, but
1586 we most likely will need dynamic relocations for
1587 __ehdr_start if we are building a PIE or shared
1589 ehdr_start
= &h
->root
;
1590 ehdr_start_save_type
= ehdr_start
->type
;
1591 memcpy (ehdr_start_save_u
,
1592 (char *) &ehdr_start
->u
+ sizeof ehdr_start
->u
.def
.next
,
1593 sizeof ehdr_start_save_u
);
1594 ehdr_start
->type
= bfd_link_hash_defined
;
1595 /* It will be converted to section-relative later. */
1596 ehdr_start
->rel_from_abs
= 1;
1597 ehdr_start
->u
.def
.section
= bfd_abs_section_ptr
;
1598 ehdr_start
->u
.def
.value
= 0;
1602 /* If we are going to make any variable assignments, we need to
1603 let the ELF backend know about them in case the variables are
1604 referred to by dynamic objects. */
1605 lang_for_each_statement (ldelf_find_statement_assignment
);
1608 /* Let the ELF backend work out the sizes of any sections required
1609 by dynamic linking. */
1610 rpath
= command_line
.rpath
;
1612 rpath
= (const char *) getenv ("LD_RUN_PATH");
1614 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1615 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
1617 const char *audit_libs
= elf_dt_audit (abfd
);
1619 /* If the input bfd contains an audit entry, we need to add it as
1620 a dep audit entry. */
1621 if (audit_libs
&& *audit_libs
!= '\0')
1623 char *cp
= xstrdup (audit_libs
);
1627 char *cp2
= strchr (cp
, config
.rpath_separator
);
1635 if (cp
!= NULL
&& *cp
!= '\0')
1636 ldelf_append_to_separated_string (&depaudit
, cp
);
1638 cp
= more
? ++cp2
: NULL
;
1644 if (! (bfd_elf_size_dynamic_sections
1645 (link_info
.output_bfd
, command_line
.soname
, rpath
,
1646 command_line
.filter_shlib
, audit
, depaudit
,
1647 (const char * const *) command_line
.auxiliary_filters
,
1648 &link_info
, &sinterp
)))
1649 einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1651 if (sinterp
!= NULL
)
1653 /* Let the user override the dynamic linker we are using. */
1654 if (command_line
.interpreter
!= NULL
)
1655 default_interpreter_name
= command_line
.interpreter
;
1656 if (default_interpreter_name
!= NULL
)
1658 sinterp
->contents
= (bfd_byte
*) default_interpreter_name
;
1659 sinterp
->size
= strlen ((char *) sinterp
->contents
) + 1;
1663 /* Look for any sections named .gnu.warning. As a GNU extensions,
1664 we treat such sections as containing warning messages. We print
1665 out the warning message, and then zero out the section size so
1666 that it does not get copied into the output file. */
1669 LANG_FOR_EACH_INPUT_STATEMENT (is
)
1675 if (is
->flags
.just_syms
)
1678 s
= bfd_get_section_by_name (is
->the_bfd
, ".gnu.warning");
1683 msg
= (char *) xmalloc ((size_t) (sz
+ 1));
1684 if (! bfd_get_section_contents (is
->the_bfd
, s
, msg
,
1686 einfo (_("%F%P: %pB: can't read contents of section .gnu.warning: %E\n"),
1689 (*link_info
.callbacks
->warning
) (&link_info
, msg
,
1690 (const char *) NULL
, is
->the_bfd
,
1691 (asection
*) NULL
, (bfd_vma
) 0);
1694 /* Clobber the section size, so that we don't waste space
1695 copying the warning into the output file. If we've already
1696 sized the output section, adjust its size. The adjustment
1697 is on rawsize because targets that size sections early will
1698 have called lang_reset_memory_regions after sizing. */
1699 if (s
->output_section
!= NULL
1700 && s
->output_section
->rawsize
>= s
->size
)
1701 s
->output_section
->rawsize
-= s
->size
;
1705 /* Also set SEC_EXCLUDE, so that local symbols defined in the
1706 warning section don't get copied to the output. */
1707 s
->flags
|= SEC_EXCLUDE
| SEC_KEEP
;
1711 before_allocation_default ();
1713 if (!bfd_elf_size_dynsym_hash_dynstr (link_info
.output_bfd
, &link_info
))
1714 einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1716 if (ehdr_start
!= NULL
)
1718 /* If we twiddled __ehdr_start to defined earlier, put it back
1720 ehdr_start
->type
= ehdr_start_save_type
;
1721 memcpy ((char *) &ehdr_start
->u
+ sizeof ehdr_start
->u
.def
.next
,
1723 sizeof ehdr_start_save_u
);
1726 /* Try to open a dynamic archive. This is where we know that ELF
1727 dynamic libraries have an extension of .so (or .sl on oddball systems
1731 ldelf_open_dynamic_archive (const char *arch
, search_dirs_type
*search
,
1732 lang_input_statement_type
*entry
)
1734 const char *filename
;
1737 bool opened
= false;
1739 if (! entry
->flags
.maybe_archive
)
1742 filename
= entry
->filename
;
1743 len
= strlen (search
->name
) + strlen (filename
);
1744 if (entry
->flags
.full_name_provided
)
1747 string
= (char *) xmalloc (len
);
1748 sprintf (string
, "%s/%s", search
->name
, filename
);
1754 len
+= strlen (arch
) + sizeof "/lib.so";
1755 #ifdef EXTRA_SHLIB_EXTENSION
1756 xlen
= (strlen (EXTRA_SHLIB_EXTENSION
) > 3
1757 ? strlen (EXTRA_SHLIB_EXTENSION
) - 3
1760 string
= (char *) xmalloc (len
+ xlen
);
1761 sprintf (string
, "%s/lib%s%s.so", search
->name
, filename
, arch
);
1762 #ifdef EXTRA_SHLIB_EXTENSION
1763 /* Try the .so extension first. If that fails build a new filename
1764 using EXTRA_SHLIB_EXTENSION. */
1765 opened
= ldfile_try_open_bfd (string
, entry
);
1767 strcpy (string
+ len
- 4, EXTRA_SHLIB_EXTENSION
);
1771 if (!opened
&& !ldfile_try_open_bfd (string
, entry
))
1777 entry
->filename
= string
;
1779 /* We have found a dynamic object to include in the link. The ELF
1780 backend linker will create a DT_NEEDED entry in the .dynamic
1781 section naming this file. If this file includes a DT_SONAME
1782 entry, it will be used. Otherwise, the ELF linker will just use
1783 the name of the file. For an archive found by searching, like
1784 this one, the DT_NEEDED entry should consist of just the name of
1785 the file, without the path information used to find it. Note
1786 that we only need to do this if we have a dynamic object; an
1787 archive will never be referenced by a DT_NEEDED entry.
1789 FIXME: This approach--using bfd_elf_set_dt_needed_name--is not
1790 very pretty. I haven't been able to think of anything that is
1792 if (bfd_check_format (entry
->the_bfd
, bfd_object
)
1793 && (entry
->the_bfd
->flags
& DYNAMIC
) != 0)
1795 ASSERT (entry
->flags
.maybe_archive
&& entry
->flags
.search_dirs
);
1797 /* Rather than duplicating the logic above. Just use the
1798 filename we recorded earlier. */
1800 if (!entry
->flags
.full_name_provided
)
1801 filename
= lbasename (entry
->filename
);
1802 bfd_elf_set_dt_needed_name (entry
->the_bfd
, filename
);
1808 /* A variant of lang_output_section_find used by place_orphan. */
1810 static lang_output_section_statement_type
*
1811 output_rel_find (int isdyn
, int rela
)
1813 lang_output_section_statement_type
*lookup
;
1814 lang_output_section_statement_type
*last
= NULL
;
1815 lang_output_section_statement_type
*last_alloc
= NULL
;
1816 lang_output_section_statement_type
*last_ro_alloc
= NULL
;
1817 lang_output_section_statement_type
*last_rel
= NULL
;
1818 lang_output_section_statement_type
*last_rel_alloc
= NULL
;
1820 for (lookup
= (void *) lang_os_list
.head
;
1822 lookup
= lookup
->next
)
1824 if (lookup
->constraint
>= 0
1825 && startswith (lookup
->name
, ".rel"))
1827 int lookrela
= lookup
->name
[4] == 'a';
1829 /* .rel.dyn must come before all other reloc sections, to suit
1834 /* Don't place after .rel.plt as doing so results in wrong
1836 if (strcmp (".plt", lookup
->name
+ 4 + lookrela
) == 0)
1839 if (rela
== lookrela
|| last_rel
== NULL
)
1841 if ((rela
== lookrela
|| last_rel_alloc
== NULL
)
1842 && lookup
->bfd_section
!= NULL
1843 && (lookup
->bfd_section
->flags
& SEC_ALLOC
) != 0)
1844 last_rel_alloc
= lookup
;
1848 if (lookup
->bfd_section
!= NULL
1849 && (lookup
->bfd_section
->flags
& SEC_ALLOC
) != 0)
1851 last_alloc
= lookup
;
1852 if ((lookup
->bfd_section
->flags
& SEC_READONLY
) != 0)
1853 last_ro_alloc
= lookup
;
1858 return last_rel_alloc
;
1864 return last_ro_alloc
;
1872 /* Return whether IN is suitable to be part of OUT. */
1875 elf_orphan_compatible (asection
*in
, asection
*out
)
1877 /* Non-zero sh_info implies a section with SHF_INFO_LINK with
1878 unknown semantics for the generic linker, or a SHT_REL/SHT_RELA
1879 section where sh_info specifies a symbol table. (We won't see
1880 SHT_GROUP, SHT_SYMTAB or SHT_DYNSYM sections here.) We clearly
1881 can't merge SHT_REL/SHT_RELA using differing symbol tables, and
1882 shouldn't merge sections with differing unknown semantics. */
1883 if (elf_section_data (out
)->this_hdr
.sh_info
1884 != elf_section_data (in
)->this_hdr
.sh_info
)
1886 /* We can't merge with a member of an output section group or merge
1887 two sections with differing SHF_EXCLUDE or other processor and OS
1888 specific flags when doing a relocatable link. */
1889 if (bfd_link_relocatable (&link_info
)
1890 && (elf_next_in_group (out
) != NULL
1891 || ((elf_section_flags (out
) ^ elf_section_flags (in
))
1892 & (SHF_MASKPROC
| SHF_MASKOS
)) != 0))
1894 return _bfd_elf_match_sections_by_type (link_info
.output_bfd
, out
,
1898 /* Place an orphan section. We use this to put random SHF_ALLOC
1899 sections in the right segment. */
1901 lang_output_section_statement_type
*
1902 ldelf_place_orphan (asection
*s
, const char *secname
, int constraint
)
1904 static struct orphan_save hold
[] =
1907 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_CODE
,
1910 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
1913 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
| SEC_THREAD_LOCAL
,
1916 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
,
1922 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
1925 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
1928 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
| SEC_SMALL_DATA
,
1934 enum orphan_save_index
1946 static int orphan_init_done
= 0;
1947 struct orphan_save
*place
;
1948 lang_output_section_statement_type
*after
;
1949 lang_output_section_statement_type
*os
;
1950 lang_output_section_statement_type
*match_by_name
= NULL
;
1952 int elfinput
= s
->owner
->xvec
->flavour
== bfd_target_elf_flavour
;
1953 int elfoutput
= link_info
.output_bfd
->xvec
->flavour
== bfd_target_elf_flavour
;
1954 unsigned int sh_type
= elfinput
? elf_section_type (s
) : SHT_NULL
;
1958 if (!bfd_link_relocatable (&link_info
)
1959 && link_info
.combreloc
1960 && (s
->flags
& SEC_ALLOC
))
1966 secname
= ".rela.dyn";
1970 secname
= ".rel.dyn";
1976 else if (startswith (secname
, ".rel"))
1978 secname
= secname
[4] == 'a' ? ".rela.dyn" : ".rel.dyn";
1983 if (!bfd_link_relocatable (&link_info
)
1986 && (s
->flags
& SEC_ALLOC
) != 0
1987 && (elf_tdata (s
->owner
)->has_gnu_osabi
& elf_gnu_osabi_mbind
) != 0
1988 && (elf_section_flags (s
) & SHF_GNU_MBIND
) != 0)
1990 /* Find the output mbind section with the same type, attributes
1991 and sh_info field. */
1992 for (os
= (void *) lang_os_list
.head
;
1995 if (os
->bfd_section
!= NULL
1996 && !bfd_is_abs_section (os
->bfd_section
)
1997 && (elf_section_flags (os
->bfd_section
) & SHF_GNU_MBIND
) != 0
1998 && ((s
->flags
& (SEC_ALLOC
2003 == (os
->bfd_section
->flags
& (SEC_ALLOC
2008 && (elf_section_data (os
->bfd_section
)->this_hdr
.sh_info
2009 == elf_section_data (s
)->this_hdr
.sh_info
))
2011 lang_add_section (&os
->children
, s
, NULL
, NULL
, os
);
2015 /* Create the output mbind section with the ".mbind." prefix
2017 if ((s
->flags
& (SEC_LOAD
| SEC_HAS_CONTENTS
)) == 0)
2018 secname
= ".mbind.bss";
2019 else if ((s
->flags
& SEC_READONLY
) == 0)
2020 secname
= ".mbind.data";
2021 else if ((s
->flags
& SEC_CODE
) == 0)
2022 secname
= ".mbind.rodata";
2024 secname
= ".mbind.text";
2025 elf_tdata (link_info
.output_bfd
)->has_gnu_osabi
|= elf_gnu_osabi_mbind
;
2028 /* Look through the script to see where to place this section. The
2029 script includes entries added by previous lang_insert_orphan
2030 calls, so this loop puts multiple compatible orphans of the same
2031 name into a single output section. */
2032 if (constraint
== 0)
2033 for (os
= lang_output_section_find (secname
);
2035 os
= next_matching_output_section_statement (os
, 0))
2037 /* If we don't match an existing output section, tell
2038 lang_insert_orphan to create a new output section. */
2039 constraint
= SPECIAL
;
2041 /* Check to see if we already have an output section statement
2042 with this name, and its bfd section has compatible flags.
2043 If the section already exists but does not have any flags
2044 set, then it has been created by the linker, possibly as a
2045 result of a --section-start command line switch. */
2046 if (os
->bfd_section
!= NULL
2047 && (os
->bfd_section
->flags
== 0
2048 || (((s
->flags
^ os
->bfd_section
->flags
)
2049 & (SEC_LOAD
| SEC_ALLOC
)) == 0
2052 || elf_orphan_compatible (s
, os
->bfd_section
)))))
2054 lang_add_section (&os
->children
, s
, NULL
, NULL
, os
);
2058 /* Save unused output sections in case we can match them
2059 against orphans later. */
2060 if (os
->bfd_section
== NULL
)
2064 /* If we didn't match an active output section, see if we matched an
2065 unused one and use that. */
2068 lang_add_section (&match_by_name
->children
, s
, NULL
, NULL
, match_by_name
);
2069 return match_by_name
;
2072 if (!orphan_init_done
)
2074 struct orphan_save
*ho
;
2076 for (ho
= hold
; ho
< hold
+ sizeof (hold
) / sizeof (hold
[0]); ++ho
)
2077 if (ho
->name
!= NULL
)
2079 ho
->os
= lang_output_section_find (ho
->name
);
2080 if (ho
->os
!= NULL
&& ho
->os
->flags
== 0)
2081 ho
->os
->flags
= ho
->flags
;
2083 orphan_init_done
= 1;
2086 /* If this is a final link, then always put .gnu.warning.SYMBOL
2087 sections into the .text section to get them out of the way. */
2088 if (bfd_link_executable (&link_info
)
2089 && startswith (s
->name
, ".gnu.warning.")
2090 && hold
[orphan_text
].os
!= NULL
)
2092 os
= hold
[orphan_text
].os
;
2093 lang_add_section (&os
->children
, s
, NULL
, NULL
, os
);
2098 if (!bfd_link_relocatable (&link_info
))
2101 while ((nexts
= bfd_get_next_section_by_name (nexts
->owner
, nexts
))
2103 if (nexts
->output_section
== NULL
2104 && (nexts
->flags
& SEC_EXCLUDE
) == 0
2105 && ((nexts
->flags
^ flags
) & (SEC_LOAD
| SEC_ALLOC
)) == 0
2106 && (nexts
->owner
->flags
& DYNAMIC
) == 0
2107 && !bfd_input_just_syms (nexts
->owner
)
2108 && _bfd_elf_match_sections_by_type (nexts
->owner
, nexts
,
2110 flags
= (((flags
^ SEC_READONLY
)
2111 | (nexts
->flags
^ SEC_READONLY
))
2115 /* Decide which segment the section should go in based on the
2116 section name and section flags. We put loadable .note sections
2117 right after the .interp section, so that the PT_NOTE segment is
2118 stored right after the program headers where the OS can read it
2119 in the first page. */
2122 if ((flags
& (SEC_ALLOC
| SEC_DEBUGGING
)) == 0)
2123 place
= &hold
[orphan_nonalloc
];
2124 else if ((flags
& SEC_ALLOC
) == 0)
2126 else if ((flags
& SEC_LOAD
) != 0
2128 ? sh_type
== SHT_NOTE
2129 : startswith (secname
, ".note")))
2130 place
= &hold
[orphan_interp
];
2131 else if ((flags
& (SEC_LOAD
| SEC_HAS_CONTENTS
| SEC_THREAD_LOCAL
)) == 0)
2132 place
= &hold
[orphan_bss
];
2133 else if ((flags
& SEC_SMALL_DATA
) != 0)
2134 place
= &hold
[orphan_sdata
];
2135 else if ((flags
& SEC_THREAD_LOCAL
) != 0)
2136 place
= &hold
[orphan_tdata
];
2137 else if ((flags
& SEC_READONLY
) == 0)
2138 place
= &hold
[orphan_data
];
2139 else if ((flags
& SEC_LOAD
) != 0
2141 ? sh_type
== SHT_RELA
|| sh_type
== SHT_REL
2142 : startswith (secname
, ".rel")))
2143 place
= &hold
[orphan_rel
];
2144 else if ((flags
& SEC_CODE
) == 0)
2145 place
= &hold
[orphan_rodata
];
2147 place
= &hold
[orphan_text
];
2152 if (place
->os
== NULL
)
2154 if (place
->name
!= NULL
)
2155 place
->os
= lang_output_section_find (place
->name
);
2158 int rela
= elfinput
? sh_type
== SHT_RELA
: secname
[4] == 'a';
2159 place
->os
= output_rel_find (isdyn
, rela
);
2165 = lang_output_section_find_by_flags (s
, flags
, &place
->os
,
2166 _bfd_elf_match_sections_by_type
);
2168 /* *ABS* is always the first output section statement. */
2169 after
= (void *) lang_os_list
.head
;
2172 return lang_insert_orphan (s
, secname
, constraint
, after
, place
, NULL
, NULL
);
2176 ldelf_before_place_orphans (void)
2180 for (abfd
= link_info
.input_bfds
;
2181 abfd
!= (bfd
*) NULL
; abfd
= abfd
->link
.next
)
2182 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
2183 && bfd_count_sections (abfd
) != 0
2184 && !bfd_input_just_syms (abfd
))
2187 for (isec
= abfd
->sections
; isec
!= NULL
; isec
= isec
->next
)
2189 /* Discard a section if any of its linked-to section has
2191 asection
*linked_to_sec
;
2192 for (linked_to_sec
= elf_linked_to_section (isec
);
2193 linked_to_sec
!= NULL
&& !linked_to_sec
->linker_mark
;
2194 linked_to_sec
= elf_linked_to_section (linked_to_sec
))
2196 if (discarded_section (linked_to_sec
))
2198 isec
->output_section
= bfd_abs_section_ptr
;
2199 isec
->flags
|= SEC_EXCLUDE
;
2202 linked_to_sec
->linker_mark
= 1;
2204 for (linked_to_sec
= elf_linked_to_section (isec
);
2205 linked_to_sec
!= NULL
&& linked_to_sec
->linker_mark
;
2206 linked_to_sec
= elf_linked_to_section (linked_to_sec
))
2207 linked_to_sec
->linker_mark
= 0;
2213 ldelf_set_output_arch (void)
2215 set_output_arch_default ();
2216 if (link_info
.output_bfd
->xvec
->flavour
== bfd_target_elf_flavour
)
2217 elf_link_info (link_info
.output_bfd
) = &link_info
;