blob: 7dec019d1f722e0a9137c9be8400cd1b0876ade1 [file] [log] [blame]
/* AIX cross support for collect2.
Copyright (C) 2009-2022 Free Software Foundation, Inc.
This file is part of GCC.
GCC 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, or (at your option) any later
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "collect2-aix.h"
/* Read SIZE bytes starting at DATA as a big-endian value. */
static inline bfd_vma
read_value (char *data, unsigned int size)
bfd_vma value;
unsigned int i;
value = 0;
for (i = 0; i < size; i++)
value <<= 8;
value += (unsigned char) data[i];
return value;
/* FIELD is a char array. Read the contents as a big-endian integer. */
read_value (FIELD, sizeof (FIELD))
/* OBJECT is a char pointer to an in-file object of type struct TYPE.
Return the address of field FIELD. */
(OBJECT) + offsetof (struct TYPE, FIELD)
/* Return the size of FIELD, which is a field of struct TYPE. */
sizeof (((struct TYPE *) (0))->FIELD)
/* OBJECT is a char pointer to an in-file object of type struct TYPE.
Read the value of field FIELD as a big-endian integer. */
/* Copy FIELD from an external structure of type TYPE at address FROM
to an internal structure pointed to by TO. */
/* Return true if STRING is less than SIZE bytes long. EXTRA_TERMINATOR
is another character (besides '\0') that acts as a terminator,
or '\0' if none. */
static bool
string_within_bounds_p (const char *string, size_t size, char extra_terminator)
const char *p;
for (p = string; p < string + size; p++)
if (*p == '\0' || *p == extra_terminator)
return true;
return false;
/* STRING is a pointer to a char array. Try to read its value as an
ASCII-encoded integer. On success, return true and store the result
in TARGET. */
(string_within_bounds_p (&(STRING)[0], sizeof (STRING), ' ') \
&& ((TARGET) = strtoul (STRING, NULL, 0), true))
/* Check that LDFILE's current object has SIZE bytes starting at OFFSET. */
static inline bool
within_object_p (LDFILE *ldfile, size_t offset, size_t size)
return offset <= ldfile->object_size && offset + size <= ldfile->object_size;
/* Try to read the file header for an XCOFF object at OFFSET bytes into
LDFILE. The object is expected to be OBJECT_SIZE bytes in size.
If the object is a member of an archive, NEXT_MEMBER is the offset
of the next member, otherwise it is -1.
Return true on success, recording the object information in LDFILE. */
static bool
read_xcoff_object (LDFILE *ldfile, size_t offset, size_t object_size,
off_t next_member)
struct internal_filehdr *internal;
char *external;
void *map;
size_t page_size;
/* First try to map the file into memory. */
page_size = getpagesize ();
ldfile->page_offset = offset & (page_size - 1);
map = mmap (NULL, object_size + ldfile->page_offset, PROT_READ,
MAP_SHARED, ldfile->fd, offset - ldfile->page_offset);
if (map == MAP_FAILED)
return false;
/* Record the success. */
ldfile->object = (char *) map + ldfile->page_offset;
ldfile->object_size = object_size;
ldfile->next_member = next_member;
/* Read the magic value to determine the type of file. */
if (!within_object_p (ldfile, 0, F_MAGIC_SIZE))
return false;
internal = &ldfile->filehdr;
external = ldfile->object;
internal->f_magic = read_value (external, F_MAGIC_SIZE);
if (internal->f_magic == U802TOCMAGIC)
if (!within_object_p (ldfile, 0, sizeof (struct external_filehdr_32)))
return false;
COPY_FIELD (internal, external, external_filehdr_32, f_nscns);
COPY_FIELD (internal, external, external_filehdr_32, f_timdat);
COPY_FIELD (internal, external, external_filehdr_32, f_symptr);
COPY_FIELD (internal, external, external_filehdr_32, f_nsyms);
COPY_FIELD (internal, external, external_filehdr_32, f_opthdr);
COPY_FIELD (internal, external, external_filehdr_32, f_flags);
return true;
else if (internal->f_magic == U803XTOCMAGIC
|| internal->f_magic == U64_TOCMAGIC)
if (!within_object_p (ldfile, 0, sizeof (struct external_filehdr_64)))
return false;
COPY_FIELD (internal, external, external_filehdr_64, f_nscns);
COPY_FIELD (internal, external, external_filehdr_64, f_timdat);
COPY_FIELD (internal, external, external_filehdr_64, f_symptr);
COPY_FIELD (internal, external, external_filehdr_64, f_nsyms);
COPY_FIELD (internal, external, external_filehdr_64, f_opthdr);
COPY_FIELD (internal, external, external_filehdr_64, f_flags);
return true;
return false;
/* Try to read an archive member at OFFSET bytes into LDFILE.
Return true on success, recording the member and object
information in LDFILE. */
static bool
read_archive_member (LDFILE *ldfile, size_t offset)
struct external_big_ar_member member;
size_t namlen;
size_t size;
off_t next_member;
if (lseek (ldfile->fd, offset, SEEK_SET) >= 0
&& read (ldfile->fd, &member, sizeof (member)) == sizeof (member)
&& PARSE_INTEGER (namlen, member.ar_namlen)
/* Stop once we reach the member table entry, which has a name
of length 0. */
&& namlen > 0
&& PARSE_INTEGER (size, member.ar_size)
&& PARSE_INTEGER (next_member, member.ar_nextoff))
/* The archive is followed by an even-padded name, then by
a magic string of length SXCOFFARFMAG. The object itself
starts after that. */
offset += sizeof (member) + namlen + SXCOFFARFMAG;
offset += offset & 1;
return read_xcoff_object (ldfile, offset, size, next_member);
return false;
/* Try to treat LDFILE as a non-empty big archive. Return true
on success, storing the member and object information for
the first member in LDFILE. */
static bool
read_big_archive (LDFILE *ldfile)
struct external_big_ar_filehdr filehdr;
size_t offset;
return (lseek (ldfile->fd, 0L, SEEK_SET) == 0
&& read (ldfile->fd, &filehdr, sizeof (filehdr)) == sizeof (filehdr)
&& memcmp (filehdr.fl_magic, FL_MAGIC_BIG_AR, FL_MAGIC_SIZE) == 0
&& PARSE_INTEGER (offset, filehdr.fl_firstmemoff)
&& read_archive_member (ldfile, offset));
/* LDFILE is a zero-initialized structure. Try to open FILENAME,
returning true on success. */
static bool
open_file (LDFILE *ldfile, const char *filename)
struct stat st;
ldfile->fd = open (filename, O_RDONLY);
if (ldfile->fd < 0)
return false;
if (read_big_archive (ldfile))
return true;
if (fstat (ldfile->fd, &st) < 0)
return false;
return read_xcoff_object (ldfile, 0, st.st_size, -1);
/* Release the memory associated with the current object, if one has
been mapped. */
static void
free_object (LDFILE *ldfile)
if (ldfile->object)
munmap (ldfile->object - ldfile->page_offset,
ldfile->object_size + ldfile->page_offset);
/* Free LDFILE and all resources associated with it. */
static void
free_ldfile (LDFILE *ldfile)
if (ldfile->fd >= 0)
close (ldfile->fd);
XDELETE (ldfile);
/* Implement the API-defined ldopen function. */
ldopen (char *filename, LDFILE *ldfile)
if (ldfile == NULL)
ldfile = XCNEW (LDFILE);
if (!open_file (ldfile, filename))
free_object (ldfile);
free_ldfile (ldfile);
return NULL;
return ldfile;
/* Implement the API-defined ldtbread function. */
ldtbread (LDFILE *ldfile, long index, SYMENT *internal)
size_t offset, name_length;
char *external;
/* Make sure that the symbol index is valid. */
if (index < 0 || index >= HEADER (ldfile).f_nsyms)
return FAILURE;
/* Work out the offset of the symbol table entry. */
offset = HEADER (ldfile).f_symptr + index * sizeof (struct external_syment);
if (!within_object_p (ldfile, offset, sizeof (struct external_syment)))
return FAILURE;
/* Read all the fields. The format differs between 32-bit and
64-bit files. */
external = ldfile->object + offset;
if (HEADER (ldfile).f_magic == U802TOCMAGIC)
/* Copy the n_zeroes/n_offset interpretation. */
internal->n_zeroes = READ_OBJECT (external, external_syment,
internal->n_offset = READ_OBJECT (external, external_syment,
/* Copy the n_name interpretation. The internal version has room
for a null terminator. */
name_length = FIELD_SIZE (external_syment, u.xcoff32.u.n_name);
memcpy (internal->n_name,
external + offsetof (struct external_syment, u.xcoff32.u.n_name),
internal->n_name[name_length] = 0;
internal->n_value = READ_OBJECT (external, external_syment,
internal->n_zeroes = 0;
internal->n_offset = READ_OBJECT (external, external_syment,
internal->n_value = READ_OBJECT (external, external_syment,
COPY_FIELD (internal, external, external_syment, n_scnum);
COPY_FIELD (internal, external, external_syment, n_type);
COPY_FIELD (internal, external, external_syment, n_sclass);
COPY_FIELD (internal, external, external_syment, n_numaux);
return SUCCESS;
/* Implement the API-defined ldgetname function. */
char *
ldgetname (LDFILE *ldfile, SYMENT *symbol)
char *name;
size_t offset;
/* If the zeroes field is nonzero, the name is in the symbol table
entry itself. */
if (symbol->n_zeroes != 0)
return symbol->n_name;
/* Otherwise, the symbol table entry contains an offset into the
string table, which starts after the end of the symbol table. */
offset = (HEADER (ldfile).f_symptr
+ HEADER (ldfile).f_nsyms * sizeof (struct external_syment)
+ symbol->n_offset);
if (offset >= ldfile->object_size)
return NULL;
/* Make sure that the name is entirely contained within the object. */
name = ldfile->object + offset;
if (!string_within_bounds_p (name, ldfile->object_size - offset, '\0'))
return NULL;
return name;
/* Implement the API-defined ldclose function. */
ldclose (LDFILE *ldfile)
free_object (ldfile);
if (ldfile->next_member >= 0
&& read_archive_member (ldfile, ldfile->next_member))
return FAILURE;
free_ldfile (ldfile);
return SUCCESS;