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gnu / binutils-gdb / 511c6575b2febee533a4d8796647bbabc2c27249 / . / bfd / xcofflink.c
blob: 49ac8efd1e8eec79bb277219d22a312dbc8b4dc2 [file] [log] [blame]
/* POWER/PowerPC XCOFF linker support.
Copyright (C) 1995-2024 Free Software Foundation, Inc.
Written by Ian Lance Taylor <ian@cygnus.com>, Cygnus Support.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include "bfd.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "coff/internal.h"
#include "coff/xcoff.h"
#include "libcoff.h"
#include "libxcoff.h"
#include "libiberty.h"
#include "xcofflink.h"
/* This file holds the XCOFF linker code. */
#undef STRING_SIZE_SIZE
#define STRING_SIZE_SIZE 4
/* The list of import files. */
struct xcoff_import_file
{
/* The next entry in the list. */
struct xcoff_import_file *next;
/* The path. */
const char *path;
/* The file name. */
const char *file;
/* The member name. */
const char *member;
};
/* Information we keep for each section in the output file during the
final link phase. */
struct xcoff_link_section_info
{
/* The relocs to be output. */
struct internal_reloc *relocs;
/* For each reloc against a global symbol whose index was not known
when the reloc was handled, the global hash table entry. */
struct xcoff_link_hash_entry **rel_hashes;
/* If there is a TOC relative reloc against a global symbol, and the
index of the TOC symbol is not known when the reloc was handled,
an entry is added to this linked list. This is not an array,
like rel_hashes, because this case is quite uncommon. */
struct xcoff_toc_rel_hash
{
struct xcoff_toc_rel_hash *next;
struct xcoff_link_hash_entry *h;
struct internal_reloc *rel;
} *toc_rel_hashes;
};
/* Information that the XCOFF linker collects about an archive. */
struct xcoff_archive_info
{
/* The archive described by this entry. */
bfd *archive;
/* The import path and import filename to use when referring to
this archive in the .loader section. */
const char *imppath;
const char *impfile;
/* True if the archive contains a dynamic object. */
unsigned int contains_shared_object_p : 1;
/* True if the previous field is valid. */
unsigned int know_contains_shared_object_p : 1;
};
struct xcoff_link_hash_table
{
struct bfd_link_hash_table root;
/* The stub hash table. */
struct bfd_hash_table stub_hash_table;
/* Info passed by the linker. */
struct bfd_xcoff_link_params *params;
/* The .debug string hash table. We need to compute this while
reading the input files, so that we know how large the .debug
section will be before we assign section positions. */
struct bfd_strtab_hash *debug_strtab;
/* The .debug section we will use for the final output. */
asection *debug_section;
/* The .loader section we will use for the final output. */
asection *loader_section;
/* The structure holding information about the .loader section. */
struct xcoff_loader_info ldinfo;
/* The .loader section header. */
struct internal_ldhdr ldhdr;
/* The .gl section we use to hold global linkage code. */
asection *linkage_section;
/* The .tc section we use to hold toc entries we build for global
linkage code. */
asection *toc_section;
/* The .ds section we use to hold function descriptors which we
create for exported symbols. */
asection *descriptor_section;
/* The list of import files. */
struct xcoff_import_file *imports;
/* Required alignment of sections within the output file. */
unsigned long file_align;
/* Whether the .text section must be read-only. */
bool textro;
/* Whether -brtl was specified. */
bool rtld;
/* Whether garbage collection was done. */
bool gc;
/* A linked list of symbols for which we have size information. */
struct xcoff_link_size_list
{
struct xcoff_link_size_list *next;
struct xcoff_link_hash_entry *h;
bfd_size_type size;
}
*size_list;
/* Information about archives. */
htab_t archive_info;
/* Magic sections: _text, _etext, _data, _edata, _end, end. */
asection *special_sections[XCOFF_NUMBER_OF_SPECIAL_SECTIONS];
};
/* Information that we pass around while doing the final link step. */
struct xcoff_final_link_info
{
/* General link information. */
struct bfd_link_info *info;
/* Output BFD. */
bfd *output_bfd;
/* Hash table for long symbol names. */
struct bfd_strtab_hash *strtab;
/* Array of information kept for each output section, indexed by the
target_index field. */
struct xcoff_link_section_info *section_info;
/* Symbol index of last C_FILE symbol (-1 if none). */
long last_file_index;
/* Contents of last C_FILE symbol. */
struct internal_syment last_file;
/* Symbol index of TOC symbol. */
long toc_symindx;
/* Start of .loader symbols. */
bfd_byte *ldsym;
/* Next .loader reloc to swap out. */
bfd_byte *ldrel;
/* File position of start of line numbers. */
file_ptr line_filepos;
/* Buffer large enough to hold swapped symbols of any input file. */
struct internal_syment *internal_syms;
/* Buffer large enough to hold output indices of symbols of any
input file. */
long *sym_indices;
/* Buffer large enough to hold output symbols for any input file. */
bfd_byte *outsyms;
/* Buffer large enough to hold external line numbers for any input
section. */
bfd_byte *linenos;
/* Buffer large enough to hold any input section. */
bfd_byte *contents;
/* Buffer large enough to hold external relocs of any input section. */
bfd_byte *external_relocs;
};
#define xcoff_stub_hash_entry(ent) \
((struct xcoff_stub_hash_entry *)(ent))
#define xcoff_stub_hash_lookup(table, string, create, copy) \
((struct xcoff_stub_hash_entry *) \
bfd_hash_lookup ((table), (string), (create), (copy)))
static bool xcoff_mark (struct bfd_link_info *, asection *);
/* Routines to read XCOFF dynamic information. This don't really
belong here, but we already have the ldsym manipulation routines
here. */
/* Read the contents of a section. */
static bfd_byte *
xcoff_get_section_contents (bfd *abfd, asection *sec)
{
if (coff_section_data (abfd, sec) == NULL)
{
size_t amt = sizeof (struct coff_section_tdata);
sec->used_by_bfd = bfd_zalloc (abfd, amt);
if (sec->used_by_bfd == NULL)
return NULL;
}
bfd_byte *contents = coff_section_data (abfd, sec)->contents;
if (contents == NULL)
{
if (bfd_malloc_and_get_section (abfd, sec, &contents))
coff_section_data (abfd, sec)->contents = contents;
else
{
free (contents);
contents = NULL;
}
}
return contents;
}
/* Get the size required to hold the dynamic symbols. */
long
_bfd_xcoff_get_dynamic_symtab_upper_bound (bfd *abfd)
{
asection *lsec;
bfd_byte *contents;
struct internal_ldhdr ldhdr;
if ((abfd->flags & DYNAMIC) == 0)
{
bfd_set_error (bfd_error_invalid_operation);
return -1;
}
lsec = bfd_get_section_by_name (abfd, ".loader");
if (lsec == NULL || (lsec->flags & SEC_HAS_CONTENTS) == 0)
{
bfd_set_error (bfd_error_no_symbols);
return -1;
}
contents = xcoff_get_section_contents (abfd, lsec);
if (!contents)
return -1;
bfd_xcoff_swap_ldhdr_in (abfd, (void *) contents, &ldhdr);
return (ldhdr.l_nsyms + 1) * sizeof (asymbol *);
}
/* Get the dynamic symbols. */
long
_bfd_xcoff_canonicalize_dynamic_symtab (bfd *abfd, asymbol **psyms)
{
asection *lsec;
bfd_byte *contents;
struct internal_ldhdr ldhdr;
const char *strings;
bfd_byte *elsym, *elsymend;
coff_symbol_type *symbuf;
if ((abfd->flags & DYNAMIC) == 0)
{
bfd_set_error (bfd_error_invalid_operation);
return -1;
}
lsec = bfd_get_section_by_name (abfd, ".loader");
if (lsec == NULL || (lsec->flags & SEC_HAS_CONTENTS) == 0)
{
bfd_set_error (bfd_error_no_symbols);
return -1;
}
contents = xcoff_get_section_contents (abfd, lsec);
if (!contents)
return -1;
bfd_xcoff_swap_ldhdr_in (abfd, contents, &ldhdr);
strings = (char *) contents + ldhdr.l_stoff;
symbuf = bfd_zalloc (abfd, ldhdr.l_nsyms * sizeof (* symbuf));
if (symbuf == NULL)
return -1;
elsym = contents + bfd_xcoff_loader_symbol_offset(abfd, &ldhdr);
elsymend = elsym + ldhdr.l_nsyms * bfd_xcoff_ldsymsz(abfd);
for (; elsym < elsymend; elsym += bfd_xcoff_ldsymsz(abfd), symbuf++, psyms++)
{
struct internal_ldsym ldsym;
bfd_xcoff_swap_ldsym_in (abfd, elsym, &ldsym);
symbuf->symbol.the_bfd = abfd;
if (ldsym._l._l_l._l_zeroes == 0)
symbuf->symbol.name = strings + ldsym._l._l_l._l_offset;
else
{
char *c;
c = bfd_alloc (abfd, (bfd_size_type) SYMNMLEN + 1);
if (c == NULL)
return -1;
memcpy (c, ldsym._l._l_name, SYMNMLEN);
c[SYMNMLEN] = '\0';
symbuf->symbol.name = c;
}
if (ldsym.l_smclas == XMC_XO)
symbuf->symbol.section = bfd_abs_section_ptr;
else
symbuf->symbol.section = coff_section_from_bfd_index (abfd,
ldsym.l_scnum);
symbuf->symbol.value = ldsym.l_value - symbuf->symbol.section->vma;
symbuf->symbol.flags = BSF_NO_FLAGS;
if ((ldsym.l_smtype & L_EXPORT) != 0)
{
if ((ldsym.l_smtype & L_WEAK) != 0)
symbuf->symbol.flags |= BSF_WEAK;
else
symbuf->symbol.flags |= BSF_GLOBAL;
}
/* FIXME: We have no way to record the other information stored
with the loader symbol. */
*psyms = (asymbol *) symbuf;
}
*psyms = NULL;
return ldhdr.l_nsyms;
}
/* Get the size required to hold the dynamic relocs. */
long
_bfd_xcoff_get_dynamic_reloc_upper_bound (bfd *abfd)
{
asection *lsec;
bfd_byte *contents;
struct internal_ldhdr ldhdr;
if ((abfd->flags & DYNAMIC) == 0)
{
bfd_set_error (bfd_error_invalid_operation);
return -1;
}
lsec = bfd_get_section_by_name (abfd, ".loader");
if (lsec == NULL || (lsec->flags & SEC_HAS_CONTENTS) == 0)
{
bfd_set_error (bfd_error_no_symbols);
return -1;
}
contents = xcoff_get_section_contents (abfd, lsec);
if (!contents)
return -1;
bfd_xcoff_swap_ldhdr_in (abfd, (struct external_ldhdr *) contents, &ldhdr);
return (ldhdr.l_nreloc + 1) * sizeof (arelent *);
}
/* Get the dynamic relocs. */
long
_bfd_xcoff_canonicalize_dynamic_reloc (bfd *abfd,
arelent **prelocs,
asymbol **syms)
{
asection *lsec;
bfd_byte *contents;
struct internal_ldhdr ldhdr;
arelent *relbuf;
bfd_byte *elrel, *elrelend;
if ((abfd->flags & DYNAMIC) == 0)
{
bfd_set_error (bfd_error_invalid_operation);
return -1;
}
lsec = bfd_get_section_by_name (abfd, ".loader");
if (lsec == NULL || (lsec->flags & SEC_HAS_CONTENTS) == 0)
{
bfd_set_error (bfd_error_no_symbols);
return -1;
}
contents = xcoff_get_section_contents (abfd, lsec);
if (!contents)
return -1;
bfd_xcoff_swap_ldhdr_in (abfd, contents, &ldhdr);
relbuf = bfd_alloc (abfd, ldhdr.l_nreloc * sizeof (arelent));
if (relbuf == NULL)
return -1;
elrel = contents + bfd_xcoff_loader_reloc_offset(abfd, &ldhdr);
elrelend = elrel + ldhdr.l_nreloc * bfd_xcoff_ldrelsz(abfd);
for (; elrel < elrelend; elrel += bfd_xcoff_ldrelsz(abfd), relbuf++,
prelocs++)
{
struct internal_ldrel ldrel;
bfd_xcoff_swap_ldrel_in (abfd, elrel, &ldrel);
if (ldrel.l_symndx >= 3)
relbuf->sym_ptr_ptr = syms + (ldrel.l_symndx - 3);
else
{
const char *name;
asection *sec;
switch (ldrel.l_symndx)
{
case 0:
name = ".text";
break;
case 1:
name = ".data";
break;
case 2:
name = ".bss";
break;
default:
abort ();
break;
}
sec = bfd_get_section_by_name (abfd, name);
if (sec == NULL)
{
bfd_set_error (bfd_error_bad_value);
return -1;
}
relbuf->sym_ptr_ptr = sec->symbol_ptr_ptr;
}
relbuf->address = ldrel.l_vaddr;
relbuf->addend = 0;
/* Most dynamic relocs have the same type. FIXME: This is only
correct if ldrel.l_rtype == 0. In other cases, we should use
a different howto. */
relbuf->howto = bfd_xcoff_dynamic_reloc_howto(abfd);
/* FIXME: We have no way to record the l_rsecnm field. */
*prelocs = relbuf;
}
*prelocs = NULL;
return ldhdr.l_nreloc;
}
/* Hash functions for xcoff_link_hash_table's archive_info. */
static hashval_t
xcoff_archive_info_hash (const void *data)
{
const struct xcoff_archive_info *info;
info = (const struct xcoff_archive_info *) data;
return htab_hash_pointer (info->archive);
}
static int
xcoff_archive_info_eq (const void *data1, const void *data2)
{
const struct xcoff_archive_info *info1;
const struct xcoff_archive_info *info2;
info1 = (const struct xcoff_archive_info *) data1;
info2 = (const struct xcoff_archive_info *) data2;
return info1->archive == info2->archive;
}
/* Return information about archive ARCHIVE. Return NULL on error. */
static struct xcoff_archive_info *
xcoff_get_archive_info (struct bfd_link_info *info, bfd *archive)
{
struct xcoff_link_hash_table *htab;
struct xcoff_archive_info *entryp, entry;
void **slot;
htab = xcoff_hash_table (info);
entry.archive = archive;
slot = htab_find_slot (htab->archive_info, &entry, INSERT);
if (!slot)
return NULL;
entryp = *slot;
if (!entryp)
{
entryp = bfd_zalloc (info->output_bfd, sizeof (entry));
if (!entryp)
return NULL;
entryp->archive = archive;
*slot = entryp;
}
return entryp;
}
/* Initialize an entry in the stub hash table. */
static struct bfd_hash_entry *
stub_hash_newfunc (struct bfd_hash_entry *entry,
struct bfd_hash_table *table,
const char *string)
{
/* Allocate the structure if it has not already been allocated by a
subclass. */
if (entry == NULL)
{
entry = bfd_hash_allocate (table,
sizeof (struct xcoff_stub_hash_entry));
if (entry == NULL)
return entry;
}
/* Call the allocation method of the superclass. */
entry = bfd_hash_newfunc (entry, table, string);
if (entry != NULL)
{
struct xcoff_stub_hash_entry *hsh;
/* Initialize the local fields. */
hsh = (struct xcoff_stub_hash_entry *) entry;
hsh->stub_type = xcoff_stub_none;
hsh->hcsect = NULL;
hsh->stub_offset = 0;
hsh->target_section = NULL;
hsh->htarget = NULL;
}
return entry;
}
/* Routine to create an entry in an XCOFF link hash table. */
static struct bfd_hash_entry *
xcoff_link_hash_newfunc (struct bfd_hash_entry *entry,
struct bfd_hash_table *table,
const char *string)
{
struct xcoff_link_hash_entry *ret = (struct xcoff_link_hash_entry *) entry;
/* Allocate the structure if it has not already been allocated by a
subclass. */
if (ret == NULL)
ret = bfd_hash_allocate (table, sizeof (* ret));
if (ret == NULL)
return NULL;
/* Call the allocation method of the superclass. */
ret = ((struct xcoff_link_hash_entry *)
_bfd_link_hash_newfunc ((struct bfd_hash_entry *) ret,
table, string));
if (ret != NULL)
{
/* Set local fields. */
ret->indx = -1;
ret->toc_section = NULL;
ret->u.toc_indx = -1;
ret->descriptor = NULL;
ret->ldsym = NULL;
ret->ldindx = -1;
ret->flags = 0;
ret->smclas = XMC_UA;
}
return (struct bfd_hash_entry *) ret;
}
/* Destroy an XCOFF link hash table. */
static void
_bfd_xcoff_bfd_link_hash_table_free (bfd *obfd)
{
struct xcoff_link_hash_table *ret;
ret = (struct xcoff_link_hash_table *) obfd->link.hash;
if (ret->archive_info)
htab_delete (ret->archive_info);
if (ret->debug_strtab)
_bfd_stringtab_free (ret->debug_strtab);
bfd_hash_table_free (&ret->stub_hash_table);
_bfd_generic_link_hash_table_free (obfd);
}
/* Create an XCOFF link hash table. */
struct bfd_link_hash_table *
_bfd_xcoff_bfd_link_hash_table_create (bfd *abfd)
{
struct xcoff_link_hash_table *ret;
bool isxcoff64 = false;
size_t amt = sizeof (* ret);
ret = bfd_zmalloc (amt);
if (ret == NULL)
return NULL;
if (!_bfd_link_hash_table_init (&ret->root, abfd, xcoff_link_hash_newfunc,
sizeof (struct xcoff_link_hash_entry)))
{
free (ret);
return NULL;
}
/* Init the stub hash table too. */
if (!bfd_hash_table_init (&ret->stub_hash_table, stub_hash_newfunc,
sizeof (struct xcoff_stub_hash_entry)))
{
_bfd_xcoff_bfd_link_hash_table_free (abfd);
return NULL;
}
isxcoff64 = bfd_coff_debug_string_prefix_length (abfd) == 4;
ret->debug_strtab = _bfd_xcoff_stringtab_init (isxcoff64);
ret->archive_info = htab_create (37, xcoff_archive_info_hash,
xcoff_archive_info_eq, NULL);
if (!ret->debug_strtab || !ret->archive_info)
{
_bfd_xcoff_bfd_link_hash_table_free (abfd);
return NULL;
}
ret->root.hash_table_free = _bfd_xcoff_bfd_link_hash_table_free;
/* The linker will always generate a full a.out header. We need to
record that fact now, before the sizeof_headers routine could be
called. */
xcoff_data (abfd)->full_aouthdr = true;
return &ret->root;
}
/* Read internal relocs for an XCOFF csect. This is a wrapper around
_bfd_coff_read_internal_relocs which tries to take advantage of any
relocs which may have been cached for the enclosing section. */
static struct internal_reloc *
xcoff_read_internal_relocs (bfd *abfd,
asection *sec,
bool cache,
bfd_byte *external_relocs,
bool require_internal,
struct internal_reloc *internal_relocs)
{
if (coff_section_data (abfd, sec) != NULL
&& coff_section_data (abfd, sec)->relocs == NULL
&& xcoff_section_data (abfd, sec) != NULL)
{
asection *enclosing;
enclosing = xcoff_section_data (abfd, sec)->enclosing;
if (enclosing != NULL
&& (coff_section_data (abfd, enclosing) == NULL
|| coff_section_data (abfd, enclosing)->relocs == NULL)
&& cache
&& enclosing->reloc_count > 0)
{
if (_bfd_coff_read_internal_relocs (abfd, enclosing, true,
external_relocs, false, NULL)
== NULL)
return NULL;
}
if (enclosing != NULL
&& coff_section_data (abfd, enclosing) != NULL
&& coff_section_data (abfd, enclosing)->relocs != NULL)
{
size_t off;
off = ((sec->rel_filepos - enclosing->rel_filepos)
/ bfd_coff_relsz (abfd));
if (! require_internal)
return coff_section_data (abfd, enclosing)->relocs + off;
memcpy (internal_relocs,
coff_section_data (abfd, enclosing)->relocs + off,
sec->reloc_count * sizeof (struct internal_reloc));
return internal_relocs;
}
}
return _bfd_coff_read_internal_relocs (abfd, sec, cache, external_relocs,
require_internal, internal_relocs);
}
/* Split FILENAME into an import path and an import filename,
storing them in *IMPPATH and *IMPFILE respectively. */
bool
bfd_xcoff_split_import_path (bfd *abfd, const char *filename,
const char **imppath, const char **impfile)
{
const char *base;
size_t length;
char *path;
base = lbasename (filename);
length = base - filename;
if (length == 0)
/* The filename has no directory component, so use an empty path. */
*imppath = "";
else if (length == 1)
/* The filename is in the root directory. */
*imppath = "/";
else
{
/* Extract the (non-empty) directory part. Note that we don't
need to strip duplicate directory separators from any part
of the string; the native linker doesn't do that either. */
path = bfd_alloc (abfd, length);
if (path == NULL)
return false;
memcpy (path, filename, length - 1);
path[length - 1] = 0;
*imppath = path;
}
*impfile = base;
return true;
}
/* Set ARCHIVE's import path as though its filename had been given
as FILENAME. */
bool
bfd_xcoff_set_archive_import_path (struct bfd_link_info *info,
bfd *archive, const char *filename)
{
struct xcoff_archive_info *archive_info;
archive_info = xcoff_get_archive_info (info, archive);
return (archive_info != NULL
&& bfd_xcoff_split_import_path (archive, filename,
&archive_info->imppath,
&archive_info->impfile));
}
/* H is an imported symbol. Set the import module's path, file and member
to IMPATH, IMPFILE and IMPMEMBER respectively. All three are null if
no specific import module is specified. */
static bool
xcoff_set_import_path (struct bfd_link_info *info,
struct xcoff_link_hash_entry *h,
const char *imppath, const char *impfile,
const char *impmember)
{
unsigned int c;
struct xcoff_import_file **pp;
/* We overload the ldindx field to hold the l_ifile value for this
symbol. */
BFD_ASSERT (h->ldsym == NULL);
BFD_ASSERT ((h->flags & XCOFF_BUILT_LDSYM) == 0);
if (imppath == NULL)
h->ldindx = -1;
else
{
/* We start c at 1 because the first entry in the import list is
reserved for the library search path. */
for (pp = &xcoff_hash_table (info)->imports, c = 1;
*pp != NULL;
pp = &(*pp)->next, ++c)
{
if (filename_cmp ((*pp)->path, imppath) == 0
&& filename_cmp ((*pp)->file, impfile) == 0
&& filename_cmp ((*pp)->member, impmember) == 0)
break;
}
if (*pp == NULL)
{
struct xcoff_import_file *n;
size_t amt = sizeof (*n);
n = bfd_alloc (info->output_bfd, amt);
if (n == NULL)
return false;
n->next = NULL;
n->path = imppath;
n->file = impfile;
n->member = impmember;
*pp = n;
}
h->ldindx = c;
}
return true;
}
/* H is the bfd symbol associated with exported .loader symbol LDSYM.
Return true if LDSYM defines H. */
static bool
xcoff_dynamic_definition_p (struct xcoff_link_hash_entry *h,
struct internal_ldsym *ldsym)
{
/* If we didn't know about H before processing LDSYM, LDSYM
definitely defines H. */
if (h->root.type == bfd_link_hash_new)
return true;
/* If H is currently a weak dynamic symbol, and if LDSYM is a strong
dynamic symbol, LDSYM trumps the current definition of H. */
if ((ldsym->l_smtype & L_WEAK) == 0
&& (h->flags & XCOFF_DEF_DYNAMIC) != 0
&& (h->flags & XCOFF_DEF_REGULAR) == 0
&& (h->root.type == bfd_link_hash_defweak
|| h->root.type == bfd_link_hash_undefweak))
return true;
/* If H is currently undefined, LDSYM defines it.
However, if H has a hidden visibility, LDSYM must not
define it. */
if ((h->flags & XCOFF_DEF_DYNAMIC) == 0
&& (h->root.type == bfd_link_hash_undefined
|| h->root.type == bfd_link_hash_undefweak)
&& (h->visibility != SYM_V_HIDDEN
&& h->visibility != SYM_V_INTERNAL))
return true;
return false;
}
/* This function is used to add symbols from a dynamic object to the
global symbol table. */
static bool
xcoff_link_add_dynamic_symbols (bfd *abfd, struct bfd_link_info *info)
{
asection *lsec;
bfd_byte *contents;
struct internal_ldhdr ldhdr;
const char *strings;
bfd_byte *elsym, *elsymend;
struct xcoff_import_file *n;
unsigned int c;
struct xcoff_import_file **pp;
/* We can only handle a dynamic object if we are generating an XCOFF
output file. */
if (info->output_bfd->xvec != abfd->xvec)
{
_bfd_error_handler
(_("%pB: XCOFF shared object when not producing XCOFF output"),
abfd);
bfd_set_error (bfd_error_invalid_operation);
return false;
}
/* The symbols we use from a dynamic object are not the symbols in
the normal symbol table, but, rather, the symbols in the export
table. If there is a global symbol in a dynamic object which is
not in the export table, the loader will not be able to find it,
so we don't want to find it either. Also, on AIX 4.1.3, shr.o in
libc.a has symbols in the export table which are not in the
symbol table. */
/* Read in the .loader section. FIXME: We should really use the
o_snloader field in the a.out header, rather than grabbing the
section by name. */
lsec = bfd_get_section_by_name (abfd, ".loader");
if (lsec == NULL || (lsec->flags & SEC_HAS_CONTENTS) == 0)
{
_bfd_error_handler
(_("%pB: dynamic object with no .loader section"),
abfd);
bfd_set_error (bfd_error_no_symbols);
return false;
}
contents = xcoff_get_section_contents (abfd, lsec);
if (!contents)
return false;
/* Remove the sections from this object, so that they do not get
included in the link. */
bfd_section_list_clear (abfd);
bfd_xcoff_swap_ldhdr_in (abfd, contents, &ldhdr);
strings = (char *) contents + ldhdr.l_stoff;
elsym = contents + bfd_xcoff_loader_symbol_offset(abfd, &ldhdr);
elsymend = elsym + ldhdr.l_nsyms * bfd_xcoff_ldsymsz(abfd);
for (; elsym < elsymend; elsym += bfd_xcoff_ldsymsz(abfd))
{
struct internal_ldsym ldsym;
char nambuf[SYMNMLEN + 1];
const char *name;
struct xcoff_link_hash_entry *h;
bfd_xcoff_swap_ldsym_in (abfd, elsym, &ldsym);
/* We are only interested in exported symbols. */
if ((ldsym.l_smtype & L_EXPORT) == 0)
continue;
if (ldsym._l._l_l._l_zeroes == 0)
name = strings + ldsym._l._l_l._l_offset;
else
{
memcpy (nambuf, ldsym._l._l_name, SYMNMLEN);
nambuf[SYMNMLEN] = '\0';
name = nambuf;
}
/* Normally we could not call xcoff_link_hash_lookup in an add
symbols routine, since we might not be using an XCOFF hash
table. However, we verified above that we are using an XCOFF
hash table. */
h = xcoff_link_hash_lookup (xcoff_hash_table (info), name, true,
true, true);
if (h == NULL)
return false;
if (!xcoff_dynamic_definition_p (h, &ldsym))
continue;
h->flags |= XCOFF_DEF_DYNAMIC;
h->smclas = ldsym.l_smclas;
if (h->smclas == XMC_XO)
{
/* This symbol has an absolute value. */
if ((ldsym.l_smtype & L_WEAK) != 0)
h->root.type = bfd_link_hash_defweak;
else
h->root.type = bfd_link_hash_defined;
h->root.u.def.section = bfd_abs_section_ptr;
h->root.u.def.value = ldsym.l_value;
}
else
{
/* Otherwise, we don't bother to actually define the symbol,
since we don't have a section to put it in anyhow.
We assume instead that an undefined XCOFF_DEF_DYNAMIC symbol
should be imported from the symbol's undef.abfd. */
if ((ldsym.l_smtype & L_WEAK) != 0)
h->root.type = bfd_link_hash_undefweak;
else
h->root.type = bfd_link_hash_undefined;
h->root.u.undef.abfd = abfd;
}
/* If this symbol defines a function descriptor, then it
implicitly defines the function code as well. */
if (h->smclas == XMC_DS
|| (h->smclas == XMC_XO && name[0] != '.'))
h->flags |= XCOFF_DESCRIPTOR;
if ((h->flags & XCOFF_DESCRIPTOR) != 0)
{
struct xcoff_link_hash_entry *hds;
hds = h->descriptor;
if (hds == NULL)
{
char *dsnm;
dsnm = bfd_malloc ((bfd_size_type) strlen (name) + 2);
if (dsnm == NULL)
return false;
dsnm[0] = '.';
strcpy (dsnm + 1, name);
hds = xcoff_link_hash_lookup (xcoff_hash_table (info), dsnm,
true, true, true);
free (dsnm);
if (hds == NULL)
return false;
hds->descriptor = h;
h->descriptor = hds;
}
if (xcoff_dynamic_definition_p (hds, &ldsym))
{
hds->root.type = h->root.type;
hds->flags |= XCOFF_DEF_DYNAMIC;
if (h->smclas == XMC_XO)
{
/* An absolute symbol appears to actually define code, not a
function descriptor. This is how some math functions are
implemented on AIX 4.1. */
hds->smclas = XMC_XO;
hds->root.u.def.section = bfd_abs_section_ptr;
hds->root.u.def.value = ldsym.l_value;
}
else
{
hds->smclas = XMC_PR;
hds->root.u.undef.abfd = abfd;
/* We do not want to add this to the undefined
symbol list. */
}
}
}
}
free (contents);
coff_section_data (abfd, lsec)->contents = NULL;
/* Record this file in the import files. */
n = bfd_alloc (abfd, (bfd_size_type) sizeof (struct xcoff_import_file));
if (n == NULL)
return false;
n->next = NULL;
if (abfd->my_archive == NULL || bfd_is_thin_archive (abfd->my_archive))
{
if (!bfd_xcoff_split_import_path (abfd, bfd_get_filename (abfd),
&n->path, &n->file))
return false;
n->member = "";
}
else
{
struct xcoff_archive_info *archive_info;
archive_info = xcoff_get_archive_info (info, abfd->my_archive);
if (!archive_info->impfile)
{
if (!bfd_xcoff_split_import_path (archive_info->archive,
bfd_get_filename (archive_info
->archive),
&archive_info->imppath,
&archive_info->impfile))
return false;
}
n->path = archive_info->imppath;
n->file = archive_info->impfile;
n->member = bfd_get_filename (abfd);
}
/* We start c at 1 because the first import file number is reserved
for LIBPATH. */
for (pp = &xcoff_hash_table (info)->imports, c = 1;
*pp != NULL;
pp = &(*pp)->next, ++c)
;
*pp = n;
xcoff_data (abfd)->import_file_id = c;
return true;
}
/* xcoff_link_create_extra_sections
Takes care of creating the .loader, .gl, .ds, .debug and sections. */
static bool
xcoff_link_create_extra_sections (bfd * abfd, struct bfd_link_info *info)
{
bool return_value = false;
if (info->output_bfd->xvec == abfd->xvec)
{
/* We need to build a .loader section, so we do it here. This
won't work if we're producing an XCOFF output file with no
XCOFF input files. FIXME. */
if (!bfd_link_relocatable (info)
&& xcoff_hash_table (info)->loader_section == NULL)
{
asection *lsec;
flagword flags = SEC_HAS_CONTENTS | SEC_IN_MEMORY;
lsec = bfd_make_section_anyway_with_flags (abfd, ".loader", flags);
if (lsec == NULL)
goto end_return;
xcoff_hash_table (info)->loader_section = lsec;
}
/* Likewise for the linkage section. */
if (xcoff_hash_table (info)->linkage_section == NULL)
{
asection *lsec;
flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
| SEC_IN_MEMORY);
lsec = bfd_make_section_anyway_with_flags (abfd, ".gl", flags);
if (lsec == NULL)
goto end_return;
xcoff_hash_table (info)->linkage_section = lsec;
lsec->alignment_power = 2;
}
/* Likewise for the TOC section. */
if (xcoff_hash_table (info)->toc_section == NULL)
{
asection *tsec;
flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
| SEC_IN_MEMORY);
tsec = bfd_make_section_anyway_with_flags (abfd, ".tc", flags);
if (tsec == NULL)
goto end_return;
xcoff_hash_table (info)->toc_section = tsec;
tsec->alignment_power = 2;
}
/* Likewise for the descriptor section. */
if (xcoff_hash_table (info)->descriptor_section == NULL)
{
asection *dsec;
flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
| SEC_IN_MEMORY);
dsec = bfd_make_section_anyway_with_flags (abfd, ".ds", flags);
if (dsec == NULL)
goto end_return;
xcoff_hash_table (info)->descriptor_section = dsec;
dsec->alignment_power = 2;
}
/* Likewise for the .debug section. */
if (xcoff_hash_table (info)->debug_section == NULL
&& info->strip != strip_all)
{
asection *dsec;
flagword flags = SEC_HAS_CONTENTS | SEC_IN_MEMORY;
dsec = bfd_make_section_anyway_with_flags (abfd, ".debug", flags);
if (dsec == NULL)
goto end_return;
xcoff_hash_table (info)->debug_section = dsec;
}
}
return_value = true;
end_return:
return return_value;
}
/* Returns the index of reloc in RELOCS with the least address greater
than or equal to ADDRESS. The relocs are sorted by address. */
static bfd_size_type
xcoff_find_reloc (struct internal_reloc *relocs,
bfd_size_type count,
bfd_vma address)
{
bfd_size_type min, max, this;
if (count < 2)
{
if (count == 1 && relocs[0].r_vaddr < address)
return 1;
else
return 0;
}
min = 0;
max = count;
/* Do a binary search over (min,max]. */
while (min + 1 < max)
{
bfd_vma raddr;
this = (max + min) / 2;
raddr = relocs[this].r_vaddr;
if (raddr > address)
max = this;
else if (raddr < address)
min = this;
else
{
min = this;
break;
}
}
if (relocs[min].r_vaddr < address)
return min + 1;
while (min > 0
&& relocs[min - 1].r_vaddr == address)
--min;
return min;
}
/* Return true if the symbol has to be added to the linker hash
table. */
static bool
xcoff_link_add_symbols_to_hash_table (struct internal_syment sym,
union internal_auxent aux)
{
/* External symbols must be added. */
if (EXTERN_SYM_P (sym.n_sclass))
return true;
/* Hidden TLS symbols must be added to verify TLS relocations
in xcoff_reloc_type_tls. */
if (sym.n_sclass == C_HIDEXT
&& ((aux.x_csect.x_smclas == XMC_TL
|| aux.x_csect.x_smclas == XMC_UL)))
return true;
return false;
}
/* Add all the symbols from an object file to the hash table.
XCOFF is a weird format. A normal XCOFF .o files will have three
COFF sections--.text, .data, and .bss--but each COFF section will
contain many csects. These csects are described in the symbol
table. From the linker's point of view, each csect must be
considered a section in its own right. For example, a TOC entry is
handled as a small XMC_TC csect. The linker must be able to merge
different TOC entries together, which means that it must be able to
extract the XMC_TC csects from the .data section of the input .o
file.
From the point of view of our linker, this is, of course, a hideous
nightmare. We cope by actually creating sections for each csect,
and discarding the original sections. We then have to handle the
relocation entries carefully, since the only way to tell which
csect they belong to is to examine the address. */
static bool
xcoff_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
{
unsigned int n_tmask;
unsigned int n_btshft;
bool default_copy;
bfd_size_type symcount;
struct xcoff_link_hash_entry **sym_hash;
asection **csect_cache;
unsigned int *lineno_counts;
bfd_size_type linesz;
asection *o;
asection *last_real;
bool keep_syms;
asection *csect;
unsigned int csect_index;
asection *first_csect;
bfd_size_type symesz;
bfd_byte *esym;
bfd_byte *esym_end;
struct reloc_info_struct
{
struct internal_reloc *relocs;
asection **csects;
bfd_byte *linenos;
} *reloc_info = NULL;
bfd_size_type amt;
unsigned short visibility;
keep_syms = obj_coff_keep_syms (abfd);
if ((abfd->flags & DYNAMIC) != 0
&& ! info->static_link)
{
if (! xcoff_link_add_dynamic_symbols (abfd, info))
return false;
}
/* Create the loader, toc, gl, ds and debug sections, if needed. */
if (! xcoff_link_create_extra_sections (abfd, info))
goto error_return;
if ((abfd->flags & DYNAMIC) != 0
&& ! info->static_link)
return true;
n_tmask = coff_data (abfd)->local_n_tmask;
n_btshft = coff_data (abfd)->local_n_btshft;
/* Define macros so that ISFCN, et. al., macros work correctly. */
#define N_TMASK n_tmask
#define N_BTSHFT n_btshft
if (info->keep_memory)
default_copy = false;
else
default_copy = true;
symcount = obj_raw_syment_count (abfd);
/* We keep a list of the linker hash table entries that correspond
to each external symbol. */
amt = symcount * sizeof (struct xcoff_link_hash_entry *);
sym_hash = bfd_zalloc (abfd, amt);
if (sym_hash == NULL && symcount != 0)
goto error_return;
coff_data (abfd)->sym_hashes = (struct coff_link_hash_entry **) sym_hash;
/* Because of the weird stuff we are doing with XCOFF csects, we can
not easily determine which section a symbol is in, so we store
the information in the tdata for the input file. */
amt = symcount * sizeof (asection *);
csect_cache = bfd_zalloc (abfd, amt);
if (csect_cache == NULL && symcount != 0)
goto error_return;
xcoff_data (abfd)->csects = csect_cache;
/* We garbage-collect line-number information on a symbol-by-symbol
basis, so we need to have quick access to the number of entries
per symbol. */
amt = symcount * sizeof (unsigned int);
lineno_counts = bfd_zalloc (abfd, amt);
if (lineno_counts == NULL && symcount != 0)
goto error_return;
xcoff_data (abfd)->lineno_counts = lineno_counts;
/* While splitting sections into csects, we need to assign the
relocs correctly. The relocs and the csects must both be in
order by VMA within a given section, so we handle this by
scanning along the relocs as we process the csects. We index
into reloc_info using the section target_index. */
amt = abfd->section_count + 1;
amt *= sizeof (struct reloc_info_struct);
reloc_info = bfd_zmalloc (amt);
if (reloc_info == NULL)
goto error_return;
/* Read in the relocs and line numbers for each section. */
linesz = bfd_coff_linesz (abfd);
last_real = NULL;
for (o = abfd->sections; o != NULL; o = o->next)
{
last_real = o;
if ((o->flags & SEC_RELOC) != 0)
{
reloc_info[o->target_index].relocs =
xcoff_read_internal_relocs (abfd, o, true, NULL, false, NULL);
amt = o->reloc_count;
amt *= sizeof (asection *);
reloc_info[o->target_index].csects = bfd_zmalloc (amt);
if (reloc_info[o->target_index].csects == NULL)
goto error_return;
}
if ((info->strip == strip_none || info->strip == strip_some)
&& o->lineno_count > 0)
{
bfd_byte *linenos;
if (bfd_seek (abfd, o->line_filepos, SEEK_SET) != 0)
goto error_return;
if (_bfd_mul_overflow (linesz, o->lineno_count, &amt))
{
bfd_set_error (bfd_error_file_too_big);
goto error_return;
}
linenos = _bfd_malloc_and_read (abfd, amt, amt);
if (linenos == NULL)
goto error_return;
reloc_info[o->target_index].linenos = linenos;
}
}
/* Don't let the linker relocation routines discard the symbols. */
obj_coff_keep_syms (abfd) = true;
csect = NULL;
csect_index = 0;
first_csect = NULL;
symesz = bfd_coff_symesz (abfd);
BFD_ASSERT (symesz == bfd_coff_auxesz (abfd));
esym = (bfd_byte *) obj_coff_external_syms (abfd);
esym_end = esym + symcount * symesz;
while (esym < esym_end)
{
struct internal_syment sym;
union internal_auxent aux;
const char *name;
char buf[SYMNMLEN + 1];
int smtyp;
asection *section;
bfd_vma value;
struct xcoff_link_hash_entry *set_toc;
bfd_coff_swap_sym_in (abfd, (void *) esym, (void *) &sym);
/* In this pass we are only interested in symbols with csect
information. */
if (!CSECT_SYM_P (sym.n_sclass))
{
/* Set csect_cache,
Normally csect is a .pr, .rw etc. created in the loop
If C_FILE or first time, handle special
Advance esym, sym_hash, csect_hash ptrs. */
if (sym.n_sclass == C_FILE || sym.n_sclass == C_DWARF)
csect = NULL;
if (csect != NULL)
*csect_cache = csect;
else if (first_csect == NULL
|| sym.n_sclass == C_FILE || sym.n_sclass == C_DWARF)
*csect_cache = coff_section_from_bfd_index (abfd, sym.n_scnum);
else
*csect_cache = NULL;
esym += (sym.n_numaux + 1) * symesz;
sym_hash += sym.n_numaux + 1;
csect_cache += sym.n_numaux + 1;
lineno_counts += sym.n_numaux + 1;
continue;
}
name = _bfd_coff_internal_syment_name (abfd, &sym, buf);
if (name == NULL)
goto error_return;
/* If this symbol has line number information attached to it,
and we're not stripping it, count the number of entries and
add them to the count for this csect. In the final link pass
we are going to attach line number information by symbol,
rather than by section, in order to more easily handle
garbage collection. */
if ((info->strip == strip_none || info->strip == strip_some)
&& sym.n_numaux > 1
&& csect != NULL
&& ISFCN (sym.n_type))
{
union internal_auxent auxlin;
bfd_coff_swap_aux_in (abfd, (void *) (esym + symesz),
sym.n_type, sym.n_sclass,
0, sym.n_numaux, (void *) &auxlin);
if (auxlin.x_sym.x_fcnary.x_fcn.x_lnnoptr != 0)
{
asection *enclosing;
bfd_signed_vma linoff;
enclosing = xcoff_section_data (abfd, csect)->enclosing;
if (enclosing == NULL)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: `%s' has line numbers but no enclosing section"),
abfd, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
linoff = (auxlin.x_sym.x_fcnary.x_fcn.x_lnnoptr
- enclosing->line_filepos);
/* Explicit cast to bfd_signed_vma for compiler. */
if (linoff < (bfd_signed_vma) (enclosing->lineno_count * linesz))
{
struct internal_lineno lin;
bfd_byte *linpstart;
linpstart = (reloc_info[enclosing->target_index].linenos
+ linoff);
bfd_coff_swap_lineno_in (abfd, (void *) linpstart, (void *) &lin);
if (lin.l_lnno == 0
&& ((bfd_size_type) lin.l_addr.l_symndx
== ((esym
- (bfd_byte *) obj_coff_external_syms (abfd))
/ symesz)))
{
bfd_byte *linpend, *linp;
linpend = (reloc_info[enclosing->target_index].linenos
+ enclosing->lineno_count * linesz);
for (linp = linpstart + linesz;
linp < linpend;
linp += linesz)
{
bfd_coff_swap_lineno_in (abfd, (void *) linp,
(void *) &lin);
if (lin.l_lnno == 0)
break;
}
*lineno_counts = (linp - linpstart) / linesz;
/* The setting of line_filepos will only be
useful if all the line number entries for a
csect are contiguous; this only matters for
error reporting. */
if (csect->line_filepos == 0)
csect->line_filepos =
auxlin.x_sym.x_fcnary.x_fcn.x_lnnoptr;
}
}
}
}
/* Record visibility. */
visibility = sym.n_type & SYM_V_MASK;
/* Pick up the csect auxiliary information. */
if (sym.n_numaux == 0)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: class %d symbol `%s' has no aux entries"),
abfd, sym.n_sclass, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
bfd_coff_swap_aux_in (abfd,
(void *) (esym + symesz * sym.n_numaux),
sym.n_type, sym.n_sclass,
sym.n_numaux - 1, sym.n_numaux,
(void *) &aux);
smtyp = SMTYP_SMTYP (aux.x_csect.x_smtyp);
section = NULL;
value = 0;
set_toc = NULL;
switch (smtyp)
{
default:
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: symbol `%s' has unrecognized csect type %d"),
abfd, name, smtyp);
bfd_set_error (bfd_error_bad_value);
goto error_return;
case XTY_ER:
/* This is an external reference. */
if (sym.n_sclass == C_HIDEXT
|| sym.n_scnum != N_UNDEF
|| aux.x_csect.x_scnlen.u64 != 0)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: bad XTY_ER symbol `%s': class %d scnum %d "
"scnlen %" PRId64),
abfd, name, sym.n_sclass, sym.n_scnum,
aux.x_csect.x_scnlen.u64);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
/* An XMC_XO external reference is actually a reference to
an absolute location. */
if (aux.x_csect.x_smclas != XMC_XO)
section = bfd_und_section_ptr;
else
{
section = bfd_abs_section_ptr;
value = sym.n_value;
}
break;
case XTY_SD:
csect = NULL;
csect_index = -(unsigned) 1;
/* When we see a TOC anchor, we record the TOC value. */
if (aux.x_csect.x_smclas == XMC_TC0)
{
if (sym.n_sclass != C_HIDEXT
|| aux.x_csect.x_scnlen.u64 != 0)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: XMC_TC0 symbol `%s' is class %d scnlen %" PRIu64),
abfd, name, sym.n_sclass, aux.x_csect.x_scnlen.u64);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
xcoff_data (abfd)->toc = sym.n_value;
}
/* We must merge TOC entries for the same symbol. We can
merge two TOC entries if they are both C_HIDEXT, they
both have the same name, they are both 4 or 8 bytes long, and
they both have a relocation table entry for an external
symbol with the same name. Unfortunately, this means
that we must look through the relocations. Ick.
Logic for 32 bit vs 64 bit.
32 bit has a csect length of 4 for TOC
64 bit has a csect length of 8 for TOC
An exception is made for TOC entries with a R_TLSML
relocation. This relocation is made for the loader.
We must check that the referenced symbol is the TOC entry
itself.
The conditions to get past the if-check are not that bad.
They are what is used to create the TOC csects in the first
place. */
if (aux.x_csect.x_smclas == XMC_TC
&& sym.n_sclass == C_HIDEXT
&& info->output_bfd->xvec == abfd->xvec
&& ((bfd_xcoff_is_xcoff32 (abfd)
&& aux.x_csect.x_scnlen.u64 == 4)
|| (bfd_xcoff_is_xcoff64 (abfd)
&& aux.x_csect.x_scnlen.u64 == 8)))
{
asection *enclosing;
struct internal_reloc *relocs;
bfd_size_type relindx;
struct internal_reloc *rel;
enclosing = coff_section_from_bfd_index (abfd, sym.n_scnum);
if (enclosing == NULL)
goto error_return;
relocs = reloc_info[enclosing->target_index].relocs;
amt = enclosing->reloc_count;
relindx = xcoff_find_reloc (relocs, amt, sym.n_value);
rel = relocs + relindx;
/* 32 bit R_POS r_size is 31
64 bit R_POS r_size is 63 */
if (relindx < enclosing->reloc_count
&& rel->r_vaddr == (bfd_vma) sym.n_value
&& (rel->r_type == R_POS ||
rel->r_type == R_TLSML)
&& ((bfd_xcoff_is_xcoff32 (abfd)
&& rel->r_size == 31)
|| (bfd_xcoff_is_xcoff64 (abfd)
&& rel->r_size == 63)))
{
bfd_byte *erelsym;
struct internal_syment relsym;
erelsym = ((bfd_byte *) obj_coff_external_syms (abfd)
+ rel->r_symndx * symesz);
bfd_coff_swap_sym_in (abfd, (void *) erelsym, (void *) &relsym);
if (EXTERN_SYM_P (relsym.n_sclass))
{
const char *relname;
char relbuf[SYMNMLEN + 1];
bool copy;
struct xcoff_link_hash_entry *h;
/* At this point we know that the TOC entry is
for an externally visible symbol. */
relname = _bfd_coff_internal_syment_name (abfd, &relsym,
relbuf);
if (relname == NULL)
goto error_return;
/* We only merge TOC entries if the TC name is
the same as the symbol name. This handles
the normal case, but not common cases like
SYM.P4 which gcc generates to store SYM + 4
in the TOC. FIXME. */
if (strcmp (name, relname) == 0)
{
copy = (! info->keep_memory
|| relsym._n._n_n._n_zeroes != 0
|| relsym._n._n_n._n_offset == 0);
h = xcoff_link_hash_lookup (xcoff_hash_table (info),
relname, true, copy,
false);
if (h == NULL)
goto error_return;
/* At this point h->root.type could be
bfd_link_hash_new. That should be OK,
since we know for sure that we will come
across this symbol as we step through the
file. */
/* We store h in *sym_hash for the
convenience of the relocate_section
function. */
*sym_hash = h;
if (h->toc_section != NULL)
{
asection **rel_csects;
/* We already have a TOC entry for this
symbol, so we can just ignore this
one. */
rel_csects =
reloc_info[enclosing->target_index].csects;
rel_csects[relindx] = bfd_und_section_ptr;
break;
}
/* We are about to create a TOC entry for
this symbol. */
set_toc = h;
}
}
else if (rel->r_type == R_TLSML)
{
csect_index = ((esym
- (bfd_byte *) obj_coff_external_syms (abfd))
/ symesz);
if (((unsigned long) rel->r_symndx) != csect_index)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: TOC entry `%s' has a R_TLSML"
"relocation not targeting itself"),
abfd, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
}
}
}
{
asection *enclosing;
/* We need to create a new section. We get the name from
the csect storage mapping class, so that the linker can
accumulate similar csects together. */
csect = bfd_xcoff_create_csect_from_smclas(abfd, &aux, name);
if (NULL == csect)
goto error_return;
/* The enclosing section is the main section : .data, .text
or .bss that the csect is coming from. */
enclosing = coff_section_from_bfd_index (abfd, sym.n_scnum);
if (enclosing == NULL)
goto error_return;
if (! bfd_is_abs_section (enclosing)
&& ((bfd_vma) sym.n_value < enclosing->vma
|| (sym.n_value + aux.x_csect.x_scnlen.u64
> enclosing->vma + enclosing->size)))
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: csect `%s' not in enclosing section"),
abfd, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
csect->vma = sym.n_value;
csect->filepos = (enclosing->filepos
+ sym.n_value
- enclosing->vma);
csect->size = aux.x_csect.x_scnlen.u64;
csect->rawsize = aux.x_csect.x_scnlen.u64;
csect->flags |= SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS;
csect->alignment_power = SMTYP_ALIGN (aux.x_csect.x_smtyp);
/* Record the enclosing section in the tdata for this new
section. */
amt = sizeof (struct coff_section_tdata);
csect->used_by_bfd = bfd_zalloc (abfd, amt);
if (csect->used_by_bfd == NULL)
goto error_return;
amt = sizeof (struct xcoff_section_tdata);
coff_section_data (abfd, csect)->tdata = bfd_zalloc (abfd, amt);
if (coff_section_data (abfd, csect)->tdata == NULL)
goto error_return;
xcoff_section_data (abfd, csect)->enclosing = enclosing;
xcoff_section_data (abfd, csect)->lineno_count =
enclosing->lineno_count;
if (enclosing->owner == abfd)
{
struct internal_reloc *relocs;
bfd_size_type relindx;
struct internal_reloc *rel;
asection **rel_csect;
relocs = reloc_info[enclosing->target_index].relocs;
amt = enclosing->reloc_count;
relindx = xcoff_find_reloc (relocs, amt, csect->vma);
rel = relocs + relindx;
rel_csect = (reloc_info[enclosing->target_index].csects
+ relindx);
csect->rel_filepos = (enclosing->rel_filepos
+ relindx * bfd_coff_relsz (abfd));
while (relindx < enclosing->reloc_count
&& *rel_csect == NULL
&& rel->r_vaddr < csect->vma + csect->size)
{
*rel_csect = csect;
csect->flags |= SEC_RELOC;
++csect->reloc_count;
++relindx;
++rel;
++rel_csect;
}
}
/* There are a number of other fields and section flags
which we do not bother to set. */
csect_index = ((esym
- (bfd_byte *) obj_coff_external_syms (abfd))
/ symesz);
xcoff_section_data (abfd, csect)->first_symndx = csect_index;
if (first_csect == NULL)
first_csect = csect;
/* If this symbol must be added to the linker hash table,
we treat it as starting at the beginning of the newly
created section. */
if (xcoff_link_add_symbols_to_hash_table (sym, aux))
{
section = csect;
value = 0;
}
/* If this is a TOC section for a symbol, record it. */
if (set_toc != NULL)
set_toc->toc_section = csect;
}
break;
case XTY_LD:
/* This is a label definition. The x_scnlen field is the
symbol index of the csect. Usually the XTY_LD symbol will
follow its appropriate XTY_SD symbol. The .set pseudo op can
cause the XTY_LD to not follow the XTY_SD symbol. */
{
bool bad;
bad = false;
if (aux.x_csect.x_scnlen.u64
>= (size_t) (esym - (bfd_byte *) obj_coff_external_syms (abfd)))
bad = true;
if (! bad)
{
section = xcoff_data (abfd)->csects[aux.x_csect.x_scnlen.u64];
if (section == NULL
|| (section->flags & SEC_HAS_CONTENTS) == 0)
bad = true;
}
if (bad)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: misplaced XTY_LD `%s'"),
abfd, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
csect = section;
value = sym.n_value - csect->vma;
}
break;
case XTY_CM:
/* This is an unitialized csect. We could base the name on
the storage mapping class, but we don't bother except for
an XMC_TD symbol. If this csect is externally visible,
it is a common symbol. We put XMC_TD symbols in sections
named .tocbss, and rely on the linker script to put that
in the TOC area. */
if (aux.x_csect.x_smclas == XMC_TD)
{
/* The linker script puts the .td section in the data
section after the .tc section. */
csect = bfd_make_section_anyway_with_flags (abfd, ".td",
SEC_ALLOC);
}
else if (aux.x_csect.x_smclas == XMC_UL)
{
/* This is a thread-local unitialized csect. */
csect = bfd_make_section_anyway_with_flags (abfd, ".tbss",
SEC_ALLOC | SEC_THREAD_LOCAL);
}
else
csect = bfd_make_section_anyway_with_flags (abfd, ".bss",
SEC_ALLOC);
if (csect == NULL)
goto error_return;
csect->vma = sym.n_value;
csect->size = aux.x_csect.x_scnlen.u64;
csect->alignment_power = SMTYP_ALIGN (aux.x_csect.x_smtyp);
/* There are a number of other fields and section flags
which we do not bother to set. */
csect_index = ((esym
- (bfd_byte *) obj_coff_external_syms (abfd))
/ symesz);
amt = sizeof (struct coff_section_tdata);
csect->used_by_bfd = bfd_zalloc (abfd, amt);
if (csect->used_by_bfd == NULL)
goto error_return;
amt = sizeof (struct xcoff_section_tdata);
coff_section_data (abfd, csect)->tdata = bfd_zalloc (abfd, amt);
if (coff_section_data (abfd, csect)->tdata == NULL)
goto error_return;
xcoff_section_data (abfd, csect)->first_symndx = csect_index;
if (first_csect == NULL)
first_csect = csect;
if (xcoff_link_add_symbols_to_hash_table (sym, aux))
{
csect->flags |= SEC_IS_COMMON;
csect->size = 0;
section = csect;
value = aux.x_csect.x_scnlen.u64;
}
break;
}
/* Check for magic symbol names. */
if ((smtyp == XTY_SD || smtyp == XTY_CM)
&& aux.x_csect.x_smclas != XMC_TC
&& aux.x_csect.x_smclas != XMC_TD)
{
int i = -1;
if (name[0] == '_')
{
if (strcmp (name, "_text") == 0)
i = XCOFF_SPECIAL_SECTION_TEXT;
else if (strcmp (name, "_etext") == 0)
i = XCOFF_SPECIAL_SECTION_ETEXT;
else if (strcmp (name, "_data") == 0)
i = XCOFF_SPECIAL_SECTION_DATA;
else if (strcmp (name, "_edata") == 0)
i = XCOFF_SPECIAL_SECTION_EDATA;
else if (strcmp (name, "_end") == 0)
i = XCOFF_SPECIAL_SECTION_END;
}
else if (name[0] == 'e' && strcmp (name, "end") == 0)
i = XCOFF_SPECIAL_SECTION_END2;
if (i != -1)
xcoff_hash_table (info)->special_sections[i] = csect;
}
/* Now we have enough information to add the symbol to the
linker hash table. */
if (xcoff_link_add_symbols_to_hash_table (sym, aux))
{
bool copy, ok;
flagword flags;
BFD_ASSERT (section != NULL);
/* We must copy the name into memory if we got it from the
syment itself, rather than the string table. */
copy = default_copy;
if (sym._n._n_n._n_zeroes != 0
|| sym._n._n_n._n_offset == 0)
copy = true;
/* Ignore global linkage code when linking statically. */
if (info->static_link
&& (smtyp == XTY_SD || smtyp == XTY_LD)
&& aux.x_csect.x_smclas == XMC_GL)
{
section = bfd_und_section_ptr;
value = 0;
}
/* The AIX linker appears to only detect multiple symbol
definitions when there is a reference to the symbol. If
a symbol is defined multiple times, and the only
references are from the same object file, the AIX linker
appears to permit it. It does not merge the different
definitions, but handles them independently. On the
other hand, if there is a reference, the linker reports
an error.
This matters because the AIX <net/net_globals.h> header
file actually defines an initialized array, so we have to
actually permit that to work.
Just to make matters even more confusing, the AIX linker
appears to permit multiple symbol definitions whenever
the second definition is in an archive rather than an
object file. This may be a consequence of the manner in
which it handles archives: I think it may load the entire
archive in as separate csects, and then let garbage
collection discard symbols.
We also have to handle the case of statically linking a
shared object, which will cause symbol redefinitions,
although this is an easier case to detect. */
else if (info->output_bfd->xvec == abfd->xvec)
{
if (! bfd_is_und_section (section))
*sym_hash = xcoff_link_hash_lookup (xcoff_hash_table (info),
name, true, copy, false);
else
/* Make a copy of the symbol name to prevent problems with
merging symbols. */
*sym_hash = ((struct xcoff_link_hash_entry *)
bfd_wrapped_link_hash_lookup (abfd, info, name,
true, true, false));
if (*sym_hash == NULL)
goto error_return;
if (((*sym_hash)->root.type == bfd_link_hash_defined
|| (*sym_hash)->root.type == bfd_link_hash_defweak)
&& ! bfd_is_und_section (section)
&& ! bfd_is_com_section (section))
{
/* This is a second definition of a defined symbol. */
if (((*sym_hash)->flags & XCOFF_DEF_REGULAR) == 0
&& ((*sym_hash)->flags & XCOFF_DEF_DYNAMIC) != 0)
{
/* The existing symbol is from a shared library.
Replace it. */
(*sym_hash)->root.type = bfd_link_hash_undefined;
(*sym_hash)->root.u.undef.abfd =
(*sym_hash)->root.u.def.section->owner;
}
else if (abfd->my_archive != NULL)
{
/* This is a redefinition in an object contained
in an archive. Just ignore it. See the
comment above. */
section = bfd_und_section_ptr;
value = 0;
}
else if (sym.n_sclass == C_AIX_WEAKEXT
|| (*sym_hash)->root.type == bfd_link_hash_defweak)
{
/* At least one of the definitions is weak.
Allow the normal rules to take effect. */
}
else if ((*sym_hash)->root.u.undef.next != NULL
|| info->hash->undefs_tail == &(*sym_hash)->root)
{
/* This symbol has been referenced. In this
case, we just continue and permit the
multiple definition error. See the comment
above about the behaviour of the AIX linker. */
}
else if ((*sym_hash)->smclas == aux.x_csect.x_smclas)
{
/* The symbols are both csects of the same
class. There is at least a chance that this
is a semi-legitimate redefinition. */
section = bfd_und_section_ptr;
value = 0;
(*sym_hash)->flags |= XCOFF_MULTIPLY_DEFINED;
}
}
else if (((*sym_hash)->flags & XCOFF_MULTIPLY_DEFINED) != 0
&& (*sym_hash)->root.type == bfd_link_hash_defined
&& (bfd_is_und_section (section)
|| bfd_is_com_section (section)))
{
/* This is a reference to a multiply defined symbol.
Report the error now. See the comment above
about the behaviour of the AIX linker. We could
also do this with warning symbols, but I'm not
sure the XCOFF linker is wholly prepared to
handle them, and that would only be a warning,
not an error. */
(*info->callbacks->multiple_definition) (info,
&(*sym_hash)->root,
NULL, NULL,
(bfd_vma) 0);
/* Try not to give this error too many times. */
(*sym_hash)->flags &= ~XCOFF_MULTIPLY_DEFINED;
}
/* If the symbol is hidden or internal, completely undo
any dynamic link state. */
if ((*sym_hash)->flags & XCOFF_DEF_DYNAMIC
&& (visibility == SYM_V_HIDDEN
|| visibility == SYM_V_INTERNAL))
(*sym_hash)->flags &= ~XCOFF_DEF_DYNAMIC;
else
{
/* Keep the most constraining visibility. */
unsigned short hvis = (*sym_hash)->visibility;
if (visibility && ( !hvis || visibility < hvis))
(*sym_hash)->visibility = visibility;
}
}
/* _bfd_generic_link_add_one_symbol may call the linker to
generate an error message, and the linker may try to read
the symbol table to give a good error. Right now, the
line numbers are in an inconsistent state, since they are
counted both in the real sections and in the new csects.
We need to leave the count in the real sections so that
the linker can report the line number of the error
correctly, so temporarily clobber the link to the csects
so that the linker will not try to read the line numbers
a second time from the csects. */
BFD_ASSERT (last_real->next == first_csect);
last_real->next = NULL;
flags = (sym.n_sclass == C_EXT ? BSF_GLOBAL : BSF_WEAK);
ok = (_bfd_generic_link_add_one_symbol
(info, abfd, name, flags, section, value, NULL, copy, true,
(struct bfd_link_hash_entry **) sym_hash));
last_real->next = first_csect;
if (!ok)
goto error_return;
if (smtyp == XTY_CM)
{
if ((*sym_hash)->root.type != bfd_link_hash_common
|| (*sym_hash)->root.u.c.p->section != csect)
/* We don't need the common csect we just created. */
csect->size = 0;
else
(*sym_hash)->root.u.c.p->alignment_power
= csect->alignment_power;
}
if (info->output_bfd->xvec == abfd->xvec)
{
int flag;
if (smtyp == XTY_ER
|| smtyp == XTY_CM
|| section == bfd_und_section_ptr)
flag = XCOFF_REF_REGULAR;
else
flag = XCOFF_DEF_REGULAR;
(*sym_hash)->flags |= flag;
if ((*sym_hash)->smclas == XMC_UA
|| flag == XCOFF_DEF_REGULAR)
(*sym_hash)->smclas = aux.x_csect.x_smclas;
}
}
if (smtyp == XTY_ER)
*csect_cache = section;
else
{
*csect_cache = csect;
if (csect != NULL)
xcoff_section_data (abfd, csect)->last_symndx
= (esym - (bfd_byte *) obj_coff_external_syms (abfd)) / symesz;
}
esym += (sym.n_numaux + 1) * symesz;
sym_hash += sym.n_numaux + 1;
csect_cache += sym.n_numaux + 1;
lineno_counts += sym.n_numaux + 1;
}
BFD_ASSERT (last_real == NULL || last_real->next == first_csect);
/* Make sure that we have seen all the relocs. */
for (o = abfd->sections; o != first_csect; o = o->next)
{
/* Debugging sections have no csects. */
if (bfd_section_flags (o) & SEC_DEBUGGING)
continue;
/* Reset the section size and the line number count, since the
data is now attached to the csects. Don't reset the size of
the .debug section, since we need to read it below in
bfd_xcoff_size_dynamic_sections. */
if (strcmp (bfd_section_name (o), ".debug") != 0)
o->size = 0;
o->lineno_count = 0;
if ((o->flags & SEC_RELOC) != 0)
{
bfd_size_type i;
struct internal_reloc *rel;
asection **rel_csect;
rel = reloc_info[o->target_index].relocs;
rel_csect = reloc_info[o->target_index].csects;
for (i = 0; i < o->reloc_count; i++, rel++, rel_csect++)
{
if (*rel_csect == NULL)
{
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: reloc %s:%" PRId64 " not in csect"),
abfd, o->name, (int64_t) i);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
/* We identify all function symbols that are the target
of a relocation, so that we can create glue code for
functions imported from dynamic objects. */
if (info->output_bfd->xvec == abfd->xvec
&& *rel_csect != bfd_und_section_ptr
&& obj_xcoff_sym_hashes (abfd)[rel->r_symndx] != NULL)
{
struct xcoff_link_hash_entry *h;
h = obj_xcoff_sym_hashes (abfd)[rel->r_symndx];
/* If the symbol name starts with a period, it is
the code of a function. If the symbol is
currently undefined, then add an undefined symbol
for the function descriptor. This should do no
harm, because any regular object that defines the
function should also define the function
descriptor. It helps, because it means that we
will identify the function descriptor with a
dynamic object if a dynamic object defines it. */
if (h->root.root.string[0] == '.'
&& h->descriptor == NULL)
{
struct xcoff_link_hash_entry *hds;
struct bfd_link_hash_entry *bh;
hds = xcoff_link_hash_lookup (xcoff_hash_table (info),
h->root.root.string + 1,
true, false, true);
if (hds == NULL)
goto error_return;
if (hds->root.type == bfd_link_hash_new)
{
bh = &hds->root;
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, hds->root.root.string,
(flagword) 0, bfd_und_section_ptr,
(bfd_vma) 0, NULL, false,
true, &bh)))
goto error_return;
hds = (struct xcoff_link_hash_entry *) bh;
}
hds->flags |= XCOFF_DESCRIPTOR;
BFD_ASSERT ((h->flags & XCOFF_DESCRIPTOR) == 0);
hds->descriptor = h;
h->descriptor = hds;
}
if (h->root.root.string[0] == '.')
h->flags |= XCOFF_CALLED;
}
}
free (reloc_info[o->target_index].csects);
reloc_info[o->target_index].csects = NULL;
/* Reset SEC_RELOC and the reloc_count, since the reloc
information is now attached to the csects. */
o->flags &=~ SEC_RELOC;
o->reloc_count = 0;
/* If we are not keeping memory, free the reloc information. */
if (! info->keep_memory
&& coff_section_data (abfd, o) != NULL)
{
free (coff_section_data (abfd, o)->relocs);
coff_section_data (abfd, o)->relocs = NULL;
}
}
/* Free up the line numbers. FIXME: We could cache these
somewhere for the final link, to avoid reading them again. */
free (reloc_info[o->target_index].linenos);
reloc_info[o->target_index].linenos = NULL;
}
free (reloc_info);
obj_coff_keep_syms (abfd) = keep_syms;
return true;
error_return:
if (reloc_info != NULL)
{
for (o = abfd->sections; o != NULL; o = o->next)
{
free (reloc_info[o->target_index].csects);
free (reloc_info[o->target_index].linenos);
}
free (reloc_info);
}
obj_coff_keep_syms (abfd) = keep_syms;
return false;
}
#undef N_TMASK
#undef N_BTSHFT
/* Add symbols from an XCOFF object file. */
static bool
xcoff_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
{
if (! _bfd_coff_get_external_symbols (abfd))
return false;
if (! xcoff_link_add_symbols (abfd, info))
return false;
if (! info->keep_memory)
{
if (! _bfd_coff_free_symbols (abfd))
return false;
}
return true;
}
/* Look through the loader symbols to see if this dynamic object
should be included in the link. The native linker uses the loader
symbols, not the normal symbol table, so we do too. */
static bool
xcoff_link_check_dynamic_ar_symbols (bfd *abfd,
struct bfd_link_info *info,
bool *pneeded,
bfd **subsbfd)
{
asection *lsec;
bfd_byte *contents;
struct internal_ldhdr ldhdr;
const char *strings;
bfd_byte *elsym, *elsymend;
*pneeded = false;
lsec = bfd_get_section_by_name (abfd, ".loader");
if (lsec == NULL || (lsec->flags & SEC_HAS_CONTENTS) == 0)
/* There are no symbols, so don't try to include it. */
return true;
contents = xcoff_get_section_contents (abfd, lsec);
if (!contents)
return false;
bfd_xcoff_swap_ldhdr_in (abfd, contents, &ldhdr);
strings = (char *) contents + ldhdr.l_stoff;
elsym = contents + bfd_xcoff_loader_symbol_offset (abfd, &ldhdr);
elsymend = elsym + ldhdr.l_nsyms * bfd_xcoff_ldsymsz (abfd);
for (; elsym < elsymend; elsym += bfd_xcoff_ldsymsz (abfd))
{
struct internal_ldsym ldsym;
char nambuf[SYMNMLEN + 1];
const char *name;
struct bfd_link_hash_entry *h;
bfd_xcoff_swap_ldsym_in (abfd, elsym, &ldsym);
/* We are only interested in exported symbols. */
if ((ldsym.l_smtype & L_EXPORT) == 0)
continue;
if (ldsym._l._l_l._l_zeroes == 0)
name = strings + ldsym._l._l_l._l_offset;
else
{
memcpy (nambuf, ldsym._l._l_name, SYMNMLEN);
nambuf[SYMNMLEN] = '\0';
name = nambuf;
}
h = bfd_link_hash_lookup (info->hash, name, false, false, true);
/* We are only interested in symbols that are currently
undefined. At this point we know that we are using an XCOFF
hash table. */
if (h != NULL
&& h->type == bfd_link_hash_undefined
&& (((struct xcoff_link_hash_entry *) h)->flags
& XCOFF_DEF_DYNAMIC) == 0)
{
if (!(*info->callbacks
->add_archive_element) (info, abfd, name, subsbfd))
continue;
*pneeded = true;
return true;
}
}
/* We do not need this shared object's .loader section. */
free (contents);
coff_section_data (abfd, lsec)->contents = NULL;
return true;
}
/* Look through the symbols to see if this object file should be
included in the link. */
static bool
xcoff_link_check_ar_symbols (bfd *abfd,
struct bfd_link_info *info,
bool *pneeded,
bfd **subsbfd)
{
bfd_size_type symesz;
bfd_byte *esym;
bfd_byte *esym_end;
*pneeded = false;
if ((abfd->flags & DYNAMIC) != 0
&& ! info->static_link
&& info->output_bfd->xvec == abfd->xvec)
return xcoff_link_check_dynamic_ar_symbols (abfd, info, pneeded, subsbfd);
symesz = bfd_coff_symesz (abfd);
esym = (bfd_byte *) obj_coff_external_syms (abfd);
esym_end = esym + obj_raw_syment_count (abfd) * symesz;
while (esym < esym_end)
{
struct internal_syment sym;
bfd_coff_swap_sym_in (abfd, (void *) esym, (void *) &sym);
esym += (sym.n_numaux + 1) * symesz;
if (EXTERN_SYM_P (sym.n_sclass) && sym.n_scnum != N_UNDEF)
{
const char *name;
char buf[SYMNMLEN + 1];
struct bfd_link_hash_entry *h;
/* This symbol is externally visible, and is defined by this
object file. */
name = _bfd_coff_internal_syment_name (abfd, &sym, buf);
if (name == NULL)
return false;
h = bfd_link_hash_lookup (info->hash, name, false, false, true);
/* We are only interested in symbols that are currently
undefined. If a symbol is currently known to be common,
XCOFF linkers do not bring in an object file which
defines it. We also don't bring in symbols to satisfy
undefined references in shared objects. */
if (h != NULL
&& h->type == bfd_link_hash_undefined
&& (info->output_bfd->xvec != abfd->xvec
|| (((struct xcoff_link_hash_entry *) h)->flags
& XCOFF_DEF_DYNAMIC) == 0))
{
if (!(*info->callbacks
->add_archive_element) (info, abfd, name, subsbfd))
continue;
*pneeded = true;
return true;
}
}
}
/* We do not need this object file. */
return true;
}
/* Check a single archive element to see if we need to include it in
the link. *PNEEDED is set according to whether this element is
needed in the link or not. This is called via
_bfd_generic_link_add_archive_symbols. */
static bool
xcoff_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info,
struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED,
bool *pneeded)
{
bool keep_syms_p;
bfd *oldbfd;
keep_syms_p = (obj_coff_external_syms (abfd) != NULL);
if (!_bfd_coff_get_external_symbols (abfd))
return false;
oldbfd = abfd;
if (!xcoff_link_check_ar_symbols (abfd, info, pneeded, &abfd))
return false;
if (*pneeded)
{
/* Potentially, the add_archive_element hook may have set a
substitute BFD for us. */
if (abfd != oldbfd)
{
if (!keep_syms_p
&& !_bfd_coff_free_symbols (oldbfd))
return false;
keep_syms_p = (obj_coff_external_syms (abfd) != NULL);
if (!_bfd_coff_get_external_symbols (abfd))
return false;
}
if (!xcoff_link_add_symbols (abfd, info))
return false;
if (info->keep_memory)
keep_syms_p = true;
}
if (!keep_syms_p)
{
if (!_bfd_coff_free_symbols (abfd))
return false;
}
return true;
}
/* Given an XCOFF BFD, add symbols to the global hash table as
appropriate. */
bool
_bfd_xcoff_bfd_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
{
switch (bfd_get_format (abfd))
{
case bfd_object:
return xcoff_link_add_object_symbols (abfd, info);
case bfd_archive:
/* If the archive has a map, do the usual search. We then need
to check the archive for dynamic objects, because they may not
appear in the archive map even though they should, perhaps, be
included. If the archive has no map, we just consider each object
file in turn, since that apparently is what the AIX native linker
does. */
if (bfd_has_map (abfd))
{
if (! (_bfd_generic_link_add_archive_symbols
(abfd, info, xcoff_link_check_archive_element)))
return false;
}
{
bfd *member;
member = bfd_openr_next_archived_file (abfd, NULL);
while (member != NULL)
{
if (bfd_check_format (member, bfd_object)
&& (info->output_bfd->xvec == member->xvec)
&& (! bfd_has_map (abfd) || (member->flags & DYNAMIC) != 0))
{
bool needed;
if (! xcoff_link_check_archive_element (member, info,
NULL, NULL, &needed))
return false;
if (needed)
member->archive_pass = -1;
}
member = bfd_openr_next_archived_file (abfd, member);
}
}
return true;
default:
bfd_set_error (bfd_error_wrong_format);
return false;
}
}
bool
_bfd_xcoff_define_common_symbol (bfd *output_bfd ATTRIBUTE_UNUSED,
struct bfd_link_info *info ATTRIBUTE_UNUSED,
struct bfd_link_hash_entry *harg)
{
struct xcoff_link_hash_entry *h;
if (!bfd_generic_define_common_symbol (output_bfd, info, harg))
return false;
h = (struct xcoff_link_hash_entry *) harg;
h->flags |= XCOFF_DEF_REGULAR;
return true;
}
/* If symbol H has not been interpreted as a function descriptor,
see whether it should be. Set up its descriptor information if so. */
static bool
xcoff_find_function (struct bfd_link_info *info,
struct xcoff_link_hash_entry *h)
{
if ((h->flags & XCOFF_DESCRIPTOR) == 0
&& h->root.root.string[0] != '.')
{
char *fnname;
struct xcoff_link_hash_entry *hfn;
size_t amt;
amt = strlen (h->root.root.string) + 2;
fnname = bfd_malloc (amt);
if (fnname == NULL)
return false;
fnname[0] = '.';
strcpy (fnname + 1, h->root.root.string);
hfn = xcoff_link_hash_lookup (xcoff_hash_table (info),
fnname, false, false, true);
free (fnname);
if (hfn != NULL
&& hfn->smclas == XMC_PR
&& (hfn->root.type == bfd_link_hash_defined
|| hfn->root.type == bfd_link_hash_defweak))
{
h->flags |= XCOFF_DESCRIPTOR;
h->descriptor = hfn;
hfn->descriptor = h;
}
}
return true;
}
/* Return true if the given bfd contains at least one shared object. */
static bool
xcoff_archive_contains_shared_object_p (struct bfd_link_info *info,
bfd *archive)
{
struct xcoff_archive_info *archive_info;
bfd *member;
archive_info = xcoff_get_archive_info (info, archive);
if (!archive_info->know_contains_shared_object_p)
{
member = bfd_openr_next_archived_file (archive, NULL);
while (member != NULL && (member->flags & DYNAMIC) == 0)
member = bfd_openr_next_archived_file (archive, member);
archive_info->contains_shared_object_p = (member != NULL);
archive_info->know_contains_shared_object_p = 1;
}
return archive_info->contains_shared_object_p;
}
/* Symbol H qualifies for export by -bexpfull. Return true if it also
qualifies for export by -bexpall. */
static bool
xcoff_covered_by_expall_p (struct xcoff_link_hash_entry *h)
{
/* Exclude symbols beginning with '_'. */
if (h->root.root.string[0] == '_')
return false;
/* Exclude archive members that would otherwise be unreferenced. */
if ((h->flags & XCOFF_MARK) == 0
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& h->root.u.def.section->owner != NULL
&& h->root.u.def.section->owner->my_archive != NULL)
return false;
return true;
}
/* Return true if symbol H qualifies for the forms of automatic export
specified by AUTO_EXPORT_FLAGS. */
static bool
xcoff_auto_export_p (struct bfd_link_info *info,
struct xcoff_link_hash_entry *h,
unsigned int auto_export_flags)
{
/* Don't automatically export things that were explicitly exported. */
if ((h->flags & XCOFF_EXPORT) != 0)
return false;
/* Don't export things that we don't define. */
if ((h->flags & XCOFF_DEF_REGULAR) == 0)
return false;
/* Don't export functions; export their descriptors instead. */
if (h->root.root.string[0] == '.')
return false;
/* Don't export hidden or internal symbols. */
if (h->visibility == SYM_V_HIDDEN
|| h->visibility == SYM_V_INTERNAL)
return false;
/* We don't export a symbol which is being defined by an object
included from an archive which contains a shared object. The
rationale is that if an archive contains both an unshared and
a shared object, then there must be some reason that the
unshared object is unshared, and we don't want to start
providing a shared version of it. In particular, this solves
a bug involving the _savefNN set of functions. gcc will call
those functions without providing a slot to restore the TOC,
so it is essential that these functions be linked in directly
and not from a shared object, which means that a shared
object which also happens to link them in must not export
them. This is confusing, but I haven't been able to think of
a different approach. Note that the symbols can, of course,
be exported explicitly. */
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
{
bfd *owner;
owner = h->root.u.def.section->owner;
if (owner != NULL
&& owner->my_archive != NULL
&& xcoff_archive_contains_shared_object_p (info, owner->my_archive))
return false;
}
/* Otherwise, all symbols are exported by -bexpfull. */
if ((auto_export_flags & XCOFF_EXPFULL) != 0)
return true;
/* Despite its name, -bexpall exports most but not all symbols. */
if ((auto_export_flags & XCOFF_EXPALL) != 0
&& xcoff_covered_by_expall_p (h))
return true;
return false;
}
/* Return true if relocation REL needs to be copied to the .loader section.
If REL is against a global symbol, H is that symbol, otherwise it
is null. */
static bool
xcoff_need_ldrel_p (struct bfd_link_info *info, struct internal_reloc *rel,
struct xcoff_link_hash_entry *h, asection *ssec)
{
if (!xcoff_hash_table (info)->loader_section)
return false;
switch (rel->r_type)
{
case R_TOC:
case R_GL:
case R_TCL:
case R_TRL:
case R_TRLA:
/* We should never need a .loader reloc for a TOC-relative reloc. */
return false;
default:
/* In this case, relocations against defined symbols can be resolved
statically. */
if (h == NULL
|| h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak
|| h->root.type == bfd_link_hash_common)
return false;
/* We will always provide a local definition of function symbols,
even if we don't have one yet. */
if ((h->flags & XCOFF_CALLED) != 0)
return false;
return true;
case R_POS:
case R_NEG:
case R_RL:
case R_RLA:
/* Absolute relocations against absolute symbols can be
resolved statically. */
if (h != NULL
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& !h->root.rel_from_abs)
{
asection *sec = h->root.u.def.section;
if (bfd_is_abs_section (sec)
|| (sec != NULL
&& bfd_is_abs_section (sec->output_section)))
return false;
}
/* Absolute relocations from read-only sections are forbidden
by AIX loader. However, they can appear in their section's
relocations. */
if (ssec != NULL
&& (ssec->output_section->flags & SEC_READONLY) != 0)
return false;
return true;
case R_TLS:
case R_TLS_LE:
case R_TLS_IE:
case R_TLS_LD:
case R_TLSM:
case R_TLSML:
return true;
}
}
/* Mark a symbol as not being garbage, including the section in which
it is defined. */
static inline bool
xcoff_mark_symbol (struct bfd_link_info *info, struct xcoff_link_hash_entry *h)
{
if ((h->flags & XCOFF_MARK) != 0)
return true;
h->flags |= XCOFF_MARK;
/* If we're marking an undefined symbol, try find some way of
defining it. */
if (!bfd_link_relocatable (info)
&& (h->flags & XCOFF_IMPORT) == 0
&& (h->flags & XCOFF_DEF_REGULAR) == 0
&& (h->root.type == bfd_link_hash_undefined
|| h->root.type == bfd_link_hash_undefweak))
{
/* First check whether this symbol can be interpreted as an
undefined function descriptor for a defined function symbol. */
if (!xcoff_find_function (info, h))
return false;
if ((h->flags & XCOFF_DESCRIPTOR) != 0
&& (h->descriptor->root.type == bfd_link_hash_defined
|| h->descriptor->root.type == bfd_link_hash_defweak))
{
/* This is a descriptor for a defined symbol, but the input
objects have not defined the descriptor itself. Fill in
the definition automatically.
Note that we do this even if we found a dynamic definition
of H. The local function definition logically overrides
the dynamic one. */
asection *sec;
sec = xcoff_hash_table (info)->descriptor_section;
h->root.type = bfd_link_hash_defined;
h->root.u.def.section = sec;
h->root.u.def.value = sec->size;
h->smclas = XMC_DS;
h->flags |= XCOFF_DEF_REGULAR;
/* The size of the function descriptor depends on whether this
is xcoff32 (12) or xcoff64 (24). */
sec->size += bfd_xcoff_function_descriptor_size (sec->owner);
/* A function descriptor uses two relocs: one for the
associated code, and one for the TOC address. */
xcoff_hash_table (info)->ldinfo.ldrel_count += 2;
sec->reloc_count += 2;
/* Mark the function itself. */
if (!xcoff_mark_symbol (info, h->descriptor))
return false;
/* Mark the TOC section, so that we get an anchor
to relocate against. */
if (!xcoff_mark (info, xcoff_hash_table (info)->toc_section))
return false;
/* We handle writing out the contents of the descriptor in
xcoff_write_global_symbol. */
}
else if (info->static_link)
/* We can't get a symbol value dynamically, so just assume
that it's undefined. */
h->flags |= XCOFF_WAS_UNDEFINED;
else if ((h->flags & XCOFF_CALLED) != 0)
{
/* This is a function symbol for which we need to create
linkage code. */
asection *sec;
struct xcoff_link_hash_entry *hds;
/* Mark the descriptor (and its TOC section). */
hds = h->descriptor;
BFD_ASSERT ((hds->root.type == bfd_link_hash_undefined
|| hds->root.type == bfd_link_hash_undefweak)
&& (hds->flags & XCOFF_DEF_REGULAR) == 0);
if (!xcoff_mark_symbol (info, hds))
return false;
/* Treat this symbol as undefined if the descriptor was. */
if ((hds->flags & XCOFF_WAS_UNDEFINED) != 0)
h->flags |= XCOFF_WAS_UNDEFINED;
/* Allocate room for the global linkage code itself. */
sec = xcoff_hash_table (info)->linkage_section;
h->root.type = bfd_link_hash_defined;
h->root.u.def.section = sec;
h->root.u.def.value = sec->size;
h->smclas = XMC_GL;
h->flags |= XCOFF_DEF_REGULAR;
sec->size += bfd_xcoff_glink_code_size (info->output_bfd);
/* The global linkage code requires a TOC entry for the
descriptor. */
if (hds->toc_section == NULL)
{
int byte_size;
/* 32 vs 64
xcoff32 uses 4 bytes in the toc.
xcoff64 uses 8 bytes in the toc. */
if (bfd_xcoff_is_xcoff64 (info->output_bfd))
byte_size = 8;
else if (bfd_xcoff_is_xcoff32 (info->output_bfd))
byte_size = 4;
else
return false;
/* Allocate room in the fallback TOC section. */
hds->toc_section = xcoff_hash_table (info)->toc_section;
hds->u.toc_offset = hds->toc_section->size;
hds->toc_section->size += byte_size;
if (!xcoff_mark (info, hds->toc_section))
return false;
/* Allocate room for a static and dynamic R_TOC
relocation. */
++xcoff_hash_table (info)->ldinfo.ldrel_count;
++hds->toc_section->reloc_count;
/* Set the index to -2 to force this symbol to
get written out. */
hds->indx = -2;
hds->flags |= XCOFF_SET_TOC | XCOFF_LDREL;
}
}
else if ((h->flags & XCOFF_DEF_DYNAMIC) == 0)
{
/* Record that the symbol was undefined, then import it.
-brtl links use a special fake import file. */
h->flags |= XCOFF_WAS_UNDEFINED | XCOFF_IMPORT;
if (xcoff_hash_table (info)->rtld)
{
if (!xcoff_set_import_path (info, h, "", "..", ""))
return false;
}
else
{
if (!xcoff_set_import_path (info, h, NULL, NULL, NULL))
return false;
}
}
}
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
{
asection *hsec;
hsec = h->root.u.def.section;
if (! bfd_is_abs_section (hsec)
&& hsec->gc_mark == 0)
{
if (! xcoff_mark (info, hsec))
return false;
}
}
if (h->toc_section != NULL
&& h->toc_section->gc_mark == 0)
{
if (! xcoff_mark (info, h->toc_section))
return false;
}
return true;
}
/* Look for a symbol called NAME. If the symbol is defined, mark it.
If the symbol exists, set FLAGS. */
static bool
xcoff_mark_symbol_by_name (struct bfd_link_info *info,
const char *name, unsigned int flags)
{
struct xcoff_link_hash_entry *h;
h = xcoff_link_hash_lookup (xcoff_hash_table (info), name,
false, false, true);
if (h != NULL)
{
h->flags |= flags;
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
{
if (!xcoff_mark (info, h->root.u.def.section))
return false;
}
}
return true;
}
/* The mark phase of garbage collection. For a given section, mark
it, and all the sections which define symbols to which it refers.
Because this function needs to look at the relocs, we also count
the number of relocs which need to be copied into the .loader
section. */
static bool
xcoff_mark (struct bfd_link_info *info, asection *sec)
{
if (bfd_is_const_section (sec)
|| sec->gc_mark != 0)
return true;
sec->gc_mark = 1;
if (sec->owner->xvec != info->output_bfd->xvec)
return true;
if (coff_section_data (sec->owner, sec) == NULL)
return true;
if (xcoff_section_data (sec->owner, sec) != NULL)
{
struct xcoff_link_hash_entry **syms;
asection **csects;
unsigned long i, first, last;
/* Mark all the symbols in this section. */
syms = obj_xcoff_sym_hashes (sec->owner);
csects = xcoff_data (sec->owner)->csects;
first = xcoff_section_data (sec->owner, sec)->first_symndx;
last = xcoff_section_data (sec->owner, sec)->last_symndx;
for (i = first; i <= last; i++)
if (csects[i] == sec
&& syms[i] != NULL
&& (syms[i]->flags & XCOFF_MARK) == 0)
{
if (!xcoff_mark_symbol (info, syms[i]))
return false;
}
}
/* Look through the section relocs. */
if ((sec->flags & SEC_RELOC) != 0
&& sec->reloc_count > 0)
{
struct internal_reloc *rel, *relend;
rel = xcoff_read_internal_relocs (sec->owner, sec, true,
NULL, false, NULL);
if (rel == NULL)
return false;
relend = rel + sec->reloc_count;
for (; rel < relend; rel++)
{
struct xcoff_link_hash_entry *h;
if ((unsigned int) rel->r_symndx
> obj_raw_syment_count (sec->owner))
continue;
h = obj_xcoff_sym_hashes (sec->owner)[rel->r_symndx];
if (h != NULL)
{
if ((h->flags & XCOFF_MARK) == 0)
{
if (!xcoff_mark_symbol (info, h))
return false;
}
}
else
{
asection *rsec;
rsec = xcoff_data (sec->owner)->csects[rel->r_symndx];
if (rsec != NULL
&& rsec->gc_mark == 0)
{
if (!xcoff_mark (info