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  1. /* opncls.c -- open and close a BFD.
  2.    Copyright (C) 1990-2015 Free Software Foundation, Inc.
  3.  
  4.    Written by Cygnus Support.
  5.  
  6.    This file is part of BFD, the Binary File Descriptor library.
  7.  
  8.    This program is free software; you can redistribute it and/or modify
  9.    it under the terms of the GNU General Public License as published by
  10.    the Free Software Foundation; either version 3 of the License, or
  11.    (at your option) any later version.
  12.  
  13.    This program is distributed in the hope that it will be useful,
  14.    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15.    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16.    GNU General Public License for more details.
  17.  
  18.    You should have received a copy of the GNU General Public License
  19.    along with this program; if not, write to the Free Software
  20.    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21.    MA 02110-1301, USA.  */
  22.  
  23. #include "sysdep.h"
  24. #include "bfd.h"
  25. #include "objalloc.h"
  26. #include "libbfd.h"
  27. #include "libiberty.h"
  28.  
  29. #ifndef S_IXUSR
  30. #define S_IXUSR 0100    /* Execute by owner.  */
  31. #endif
  32. #ifndef S_IXGRP
  33. #define S_IXGRP 0010    /* Execute by group.  */
  34. #endif
  35. #ifndef S_IXOTH
  36. #define S_IXOTH 0001    /* Execute by others.  */
  37. #endif
  38.  
  39. /* Counters used to initialize the bfd identifier.  */
  40.  
  41. static unsigned int bfd_id_counter = 0;
  42. static unsigned int bfd_reserved_id_counter = 0;
  43.  
  44. /*
  45. CODE_FRAGMENT
  46. .{* Set to N to open the next N BFDs using an alternate id space.  *}
  47. .extern unsigned int bfd_use_reserved_id;
  48. */
  49. unsigned int bfd_use_reserved_id = 0;
  50.  
  51. /* fdopen is a loser -- we should use stdio exclusively.  Unfortunately
  52.    if we do that we can't use fcntl.  */
  53.  
  54. /* Return a new BFD.  All BFD's are allocated through this routine.  */
  55.  
  56. bfd *
  57. _bfd_new_bfd (void)
  58. {
  59.   bfd *nbfd;
  60.  
  61.   nbfd = (bfd *) bfd_zmalloc (sizeof (bfd));
  62.   if (nbfd == NULL)
  63.     return NULL;
  64.  
  65.   if (bfd_use_reserved_id)
  66.     {
  67.       nbfd->id = --bfd_reserved_id_counter;
  68.       --bfd_use_reserved_id;
  69.     }
  70.   else
  71.     nbfd->id = bfd_id_counter++;
  72.  
  73.   nbfd->memory = objalloc_create ();
  74.   if (nbfd->memory == NULL)
  75.     {
  76.       bfd_set_error (bfd_error_no_memory);
  77.       free (nbfd);
  78.       return NULL;
  79.     }
  80.  
  81.   nbfd->arch_info = &bfd_default_arch_struct;
  82.  
  83.   if (!bfd_hash_table_init_n (& nbfd->section_htab, bfd_section_hash_newfunc,
  84.                               sizeof (struct section_hash_entry), 13))
  85.     {
  86.       free (nbfd);
  87.       return NULL;
  88.     }
  89.  
  90.   return nbfd;
  91. }
  92.  
  93. static const struct bfd_iovec opncls_iovec;
  94.  
  95. /* Allocate a new BFD as a member of archive OBFD.  */
  96.  
  97. bfd *
  98. _bfd_new_bfd_contained_in (bfd *obfd)
  99. {
  100.   bfd *nbfd;
  101.  
  102.   nbfd = _bfd_new_bfd ();
  103.   if (nbfd == NULL)
  104.     return NULL;
  105.   nbfd->xvec = obfd->xvec;
  106.   nbfd->iovec = obfd->iovec;
  107.   if (obfd->iovec == &opncls_iovec)
  108.     nbfd->iostream = obfd->iostream;
  109.   nbfd->my_archive = obfd;
  110.   nbfd->direction = read_direction;
  111.   nbfd->target_defaulted = obfd->target_defaulted;
  112.   nbfd->lto_output = obfd->lto_output;
  113.   nbfd->no_export = obfd->no_export;
  114.   return nbfd;
  115. }
  116.  
  117. /* Delete a BFD.  */
  118.  
  119. static void
  120. _bfd_delete_bfd (bfd *abfd)
  121. {
  122.   if (abfd->memory)
  123.     {
  124.       bfd_hash_table_free (&abfd->section_htab);
  125.       objalloc_free ((struct objalloc *) abfd->memory);
  126.     }
  127.  
  128.   if (abfd->filename)
  129.     free ((char *) abfd->filename);
  130.   free (abfd->arelt_data);
  131.   free (abfd);
  132. }
  133.  
  134. /* Free objalloc memory.  */
  135.  
  136. bfd_boolean
  137. _bfd_free_cached_info (bfd *abfd)
  138. {
  139.   if (abfd->memory)
  140.     {
  141.       bfd_hash_table_free (&abfd->section_htab);
  142.       objalloc_free ((struct objalloc *) abfd->memory);
  143.  
  144.       abfd->sections = NULL;
  145.       abfd->section_last = NULL;
  146.       abfd->outsymbols = NULL;
  147.       abfd->tdata.any = NULL;
  148.       abfd->usrdata = NULL;
  149.       abfd->memory = NULL;
  150.     }
  151.  
  152.   return TRUE;
  153. }
  154.  
  155. /*
  156. SECTION
  157.         Opening and closing BFDs
  158.  
  159. SUBSECTION
  160.         Functions for opening and closing
  161. */
  162.  
  163. /*
  164. FUNCTION
  165.         bfd_fopen
  166.  
  167. SYNOPSIS
  168.         bfd *bfd_fopen (const char *filename, const char *target,
  169.                         const char *mode, int fd);
  170.  
  171. DESCRIPTION
  172.         Open the file @var{filename} with the target @var{target}.
  173.         Return a pointer to the created BFD.  If @var{fd} is not -1,
  174.         then <<fdopen>> is used to open the file; otherwise, <<fopen>>
  175.         is used.  @var{mode} is passed directly to <<fopen>> or
  176.         <<fdopen>>.
  177.  
  178.         Calls <<bfd_find_target>>, so @var{target} is interpreted as by
  179.         that function.
  180.  
  181.         The new BFD is marked as cacheable iff @var{fd} is -1.
  182.  
  183.         If <<NULL>> is returned then an error has occured.   Possible errors
  184.         are <<bfd_error_no_memory>>, <<bfd_error_invalid_target>> or
  185.         <<system_call>> error.
  186.  
  187.         On error, @var{fd} is always closed.
  188.  
  189.         A copy of the @var{filename} argument is stored in the newly created
  190.         BFD.  It can be accessed via the bfd_get_filename() macro.
  191. */
  192.  
  193. bfd *
  194. bfd_fopen (const char *filename, const char *target, const char *mode, int fd)
  195. {
  196.   bfd *nbfd;
  197.   const bfd_target *target_vec;
  198.  
  199.   nbfd = _bfd_new_bfd ();
  200.   if (nbfd == NULL)
  201.     {
  202.       if (fd != -1)
  203.         close (fd);
  204.       return NULL;
  205.     }
  206.  
  207.   target_vec = bfd_find_target (target, nbfd);
  208.   if (target_vec == NULL)
  209.     {
  210.       if (fd != -1)
  211.         close (fd);
  212.       _bfd_delete_bfd (nbfd);
  213.       return NULL;
  214.     }
  215.  
  216. #ifdef HAVE_FDOPEN
  217.   if (fd != -1)
  218.     nbfd->iostream = fdopen (fd, mode);
  219.   else
  220. #endif
  221.     nbfd->iostream = real_fopen (filename, mode);
  222.   if (nbfd->iostream == NULL)
  223.     {
  224.       bfd_set_error (bfd_error_system_call);
  225.       _bfd_delete_bfd (nbfd);
  226.       return NULL;
  227.     }
  228.  
  229.   /* OK, put everything where it belongs.  */
  230.  
  231.   /* PR 11983: Do not cache the original filename, but
  232.      rather make a copy - the original might go away.  */
  233.   nbfd->filename = xstrdup (filename);
  234.  
  235.   /* Figure out whether the user is opening the file for reading,
  236.      writing, or both, by looking at the MODE argument.  */
  237.   if ((mode[0] == 'r' || mode[0] == 'w' || mode[0] == 'a')
  238.       && mode[1] == '+')
  239.     nbfd->direction = both_direction;
  240.   else if (mode[0] == 'r')
  241.     nbfd->direction = read_direction;
  242.   else
  243.     nbfd->direction = write_direction;
  244.  
  245.   if (! bfd_cache_init (nbfd))
  246.     {
  247.       _bfd_delete_bfd (nbfd);
  248.       return NULL;
  249.     }
  250.   nbfd->opened_once = TRUE;
  251.  
  252.   /* If we opened the file by name, mark it cacheable; we can close it
  253.      and reopen it later.  However, if a file descriptor was provided,
  254.      then it may have been opened with special flags that make it
  255.      unsafe to close and reopen the file.  */
  256.   if (fd == -1)
  257.     (void) bfd_set_cacheable (nbfd, TRUE);
  258.  
  259.   return nbfd;
  260. }
  261.  
  262. /*
  263. FUNCTION
  264.         bfd_openr
  265.  
  266. SYNOPSIS
  267.         bfd *bfd_openr (const char *filename, const char *target);
  268.  
  269. DESCRIPTION
  270.         Open the file @var{filename} (using <<fopen>>) with the target
  271.         @var{target}.  Return a pointer to the created BFD.
  272.  
  273.         Calls <<bfd_find_target>>, so @var{target} is interpreted as by
  274.         that function.
  275.  
  276.         If <<NULL>> is returned then an error has occured.   Possible errors
  277.         are <<bfd_error_no_memory>>, <<bfd_error_invalid_target>> or
  278.         <<system_call>> error.
  279.  
  280.         A copy of the @var{filename} argument is stored in the newly created
  281.         BFD.  It can be accessed via the bfd_get_filename() macro.
  282. */
  283.  
  284. bfd *
  285. bfd_openr (const char *filename, const char *target)
  286. {
  287.   return bfd_fopen (filename, target, FOPEN_RB, -1);
  288. }
  289.  
  290. /* Don't try to `optimize' this function:
  291.  
  292.    o - We lock using stack space so that interrupting the locking
  293.        won't cause a storage leak.
  294.    o - We open the file stream last, since we don't want to have to
  295.        close it if anything goes wrong.  Closing the stream means closing
  296.        the file descriptor too, even though we didn't open it.  */
  297. /*
  298. FUNCTION
  299.         bfd_fdopenr
  300.  
  301. SYNOPSIS
  302.         bfd *bfd_fdopenr (const char *filename, const char *target, int fd);
  303.  
  304. DESCRIPTION
  305.         <<bfd_fdopenr>> is to <<bfd_fopenr>> much like <<fdopen>> is to
  306.         <<fopen>>.  It opens a BFD on a file already described by the
  307.         @var{fd} supplied.
  308.  
  309.         When the file is later <<bfd_close>>d, the file descriptor will
  310.         be closed.  If the caller desires that this file descriptor be
  311.         cached by BFD (opened as needed, closed as needed to free
  312.         descriptors for other opens), with the supplied @var{fd} used as
  313.         an initial file descriptor (but subject to closure at any time),
  314.         call bfd_set_cacheable(bfd, 1) on the returned BFD.  The default
  315.         is to assume no caching; the file descriptor will remain open
  316.         until <<bfd_close>>, and will not be affected by BFD operations
  317.         on other files.
  318.  
  319.         Possible errors are <<bfd_error_no_memory>>,
  320.         <<bfd_error_invalid_target>> and <<bfd_error_system_call>>.
  321.  
  322.         On error, @var{fd} is closed.
  323.  
  324.         A copy of the @var{filename} argument is stored in the newly created
  325.         BFD.  It can be accessed via the bfd_get_filename() macro.
  326. */
  327.  
  328. bfd *
  329. bfd_fdopenr (const char *filename, const char *target, int fd)
  330. {
  331.   const char *mode;
  332. #if defined(HAVE_FCNTL) && defined(F_GETFL)
  333.   int fdflags;
  334. #endif
  335.  
  336. #if ! defined(HAVE_FCNTL) || ! defined(F_GETFL)
  337.   mode = FOPEN_RUB; /* Assume full access.  */
  338. #else
  339.   fdflags = fcntl (fd, F_GETFL, NULL);
  340.   if (fdflags == -1)
  341.     {
  342.       int save = errno;
  343.  
  344.       close (fd);
  345.       errno = save;
  346.       bfd_set_error (bfd_error_system_call);
  347.       return NULL;
  348.     }
  349.  
  350.   /* (O_ACCMODE) parens are to avoid Ultrix header file bug.  */
  351.   switch (fdflags & (O_ACCMODE))
  352.     {
  353.     case O_RDONLY: mode = FOPEN_RB; break;
  354.     case O_WRONLY: mode = FOPEN_RUB; break;
  355.     case O_RDWR:   mode = FOPEN_RUB; break;
  356.     default: abort ();
  357.     }
  358. #endif
  359.  
  360.   return bfd_fopen (filename, target, mode, fd);
  361. }
  362.  
  363. /*
  364. FUNCTION
  365.         bfd_openstreamr
  366.  
  367. SYNOPSIS
  368.         bfd *bfd_openstreamr (const char * filename, const char * target, void * stream);
  369.  
  370. DESCRIPTION
  371.  
  372.         Open a BFD for read access on an existing stdio stream.  When
  373.         the BFD is passed to <<bfd_close>>, the stream will be closed.
  374.  
  375.         A copy of the @var{filename} argument is stored in the newly created
  376.         BFD.  It can be accessed via the bfd_get_filename() macro.
  377. */
  378.  
  379. bfd *
  380. bfd_openstreamr (const char *filename, const char *target, void *streamarg)
  381. {
  382.   FILE *stream = (FILE *) streamarg;
  383.   bfd *nbfd;
  384.   const bfd_target *target_vec;
  385.  
  386.   nbfd = _bfd_new_bfd ();
  387.   if (nbfd == NULL)
  388.     return NULL;
  389.  
  390.   target_vec = bfd_find_target (target, nbfd);
  391.   if (target_vec == NULL)
  392.     {
  393.       _bfd_delete_bfd (nbfd);
  394.       return NULL;
  395.     }
  396.  
  397.   nbfd->iostream = stream;
  398.   /* PR 11983: Do not cache the original filename, but
  399.      rather make a copy - the original might go away.  */
  400.   nbfd->filename = xstrdup (filename);
  401.   nbfd->direction = read_direction;
  402.  
  403.   if (! bfd_cache_init (nbfd))
  404.     {
  405.       _bfd_delete_bfd (nbfd);
  406.       return NULL;
  407.     }
  408.  
  409.   return nbfd;
  410. }
  411.  
  412. /*
  413. FUNCTION
  414.         bfd_openr_iovec
  415.  
  416. SYNOPSIS
  417.         bfd *bfd_openr_iovec (const char *filename, const char *target,
  418.                               void *(*open_func) (struct bfd *nbfd,
  419.                                                   void *open_closure),
  420.                               void *open_closure,
  421.                               file_ptr (*pread_func) (struct bfd *nbfd,
  422.                                                       void *stream,
  423.                                                       void *buf,
  424.                                                       file_ptr nbytes,
  425.                                                       file_ptr offset),
  426.                               int (*close_func) (struct bfd *nbfd,
  427.                                                  void *stream),
  428.                               int (*stat_func) (struct bfd *abfd,
  429.                                                 void *stream,
  430.                                                 struct stat *sb));
  431.  
  432. DESCRIPTION
  433.  
  434.         Create and return a BFD backed by a read-only @var{stream}.
  435.         The @var{stream} is created using @var{open_func}, accessed using
  436.         @var{pread_func} and destroyed using @var{close_func}.
  437.  
  438.         Calls <<bfd_find_target>>, so @var{target} is interpreted as by
  439.         that function.
  440.  
  441.         Calls @var{open_func} (which can call <<bfd_zalloc>> and
  442.         <<bfd_get_filename>>) to obtain the read-only stream backing
  443.         the BFD.  @var{open_func} either succeeds returning the
  444.         non-<<NULL>> @var{stream}, or fails returning <<NULL>>
  445.         (setting <<bfd_error>>).
  446.  
  447.         Calls @var{pread_func} to request @var{nbytes} of data from
  448.         @var{stream} starting at @var{offset} (e.g., via a call to
  449.         <<bfd_read>>).  @var{pread_func} either succeeds returning the
  450.         number of bytes read (which can be less than @var{nbytes} when
  451.         end-of-file), or fails returning -1 (setting <<bfd_error>>).
  452.  
  453.         Calls @var{close_func} when the BFD is later closed using
  454.         <<bfd_close>>.  @var{close_func} either succeeds returning 0, or
  455.         fails returning -1 (setting <<bfd_error>>).
  456.  
  457.         Calls @var{stat_func} to fill in a stat structure for bfd_stat,
  458.         bfd_get_size, and bfd_get_mtime calls.  @var{stat_func} returns 0
  459.         on success, or returns -1 on failure (setting <<bfd_error>>).
  460.  
  461.         If <<bfd_openr_iovec>> returns <<NULL>> then an error has
  462.         occurred.  Possible errors are <<bfd_error_no_memory>>,
  463.         <<bfd_error_invalid_target>> and <<bfd_error_system_call>>.
  464.  
  465.         A copy of the @var{filename} argument is stored in the newly created
  466.         BFD.  It can be accessed via the bfd_get_filename() macro.
  467. */
  468.  
  469. struct opncls
  470. {
  471.   void *stream;
  472.   file_ptr (*pread) (struct bfd *abfd, void *stream, void *buf,
  473.                      file_ptr nbytes, file_ptr offset);
  474.   int (*close) (struct bfd *abfd, void *stream);
  475.   int (*stat) (struct bfd *abfd, void *stream, struct stat *sb);
  476.   file_ptr where;
  477. };
  478.  
  479. static file_ptr
  480. opncls_btell (struct bfd *abfd)
  481. {
  482.   struct opncls *vec = (struct opncls *) abfd->iostream;
  483.   return vec->where;
  484. }
  485.  
  486. static int
  487. opncls_bseek (struct bfd *abfd, file_ptr offset, int whence)
  488. {
  489.   struct opncls *vec = (struct opncls *) abfd->iostream;
  490.   switch (whence)
  491.     {
  492.     case SEEK_SET: vec->where = offset; break;
  493.     case SEEK_CUR: vec->where += offset; break;
  494.     case SEEK_END: return -1;
  495.     }
  496.   return 0;
  497. }
  498.  
  499. static file_ptr
  500. opncls_bread (struct bfd *abfd, void *buf, file_ptr nbytes)
  501. {
  502.   struct opncls *vec = (struct opncls *) abfd->iostream;
  503.   file_ptr nread = (vec->pread) (abfd, vec->stream, buf, nbytes, vec->where);
  504.   if (nread < 0)
  505.     return nread;
  506.   vec->where += nread;
  507.   return nread;
  508. }
  509.  
  510. static file_ptr
  511. opncls_bwrite (struct bfd *abfd ATTRIBUTE_UNUSED,
  512.               const void *where ATTRIBUTE_UNUSED,
  513.               file_ptr nbytes ATTRIBUTE_UNUSED)
  514. {
  515.   return -1;
  516. }
  517.  
  518. static int
  519. opncls_bclose (struct bfd *abfd)
  520. {
  521.   struct opncls *vec = (struct opncls *) abfd->iostream;
  522.   /* Since the VEC's memory is bound to the bfd deleting the bfd will
  523.      free it.  */
  524.   int status = 0;
  525.   if (vec->close != NULL)
  526.     status = (vec->close) (abfd, vec->stream);
  527.   abfd->iostream = NULL;
  528.   return status;
  529. }
  530.  
  531. static int
  532. opncls_bflush (struct bfd *abfd ATTRIBUTE_UNUSED)
  533. {
  534.   return 0;
  535. }
  536.  
  537. static int
  538. opncls_bstat (struct bfd *abfd, struct stat *sb)
  539. {
  540.   struct opncls *vec = (struct opncls *) abfd->iostream;
  541.  
  542.   memset (sb, 0, sizeof (*sb));
  543.   if (vec->stat == NULL)
  544.     return 0;
  545.  
  546.   return (vec->stat) (abfd, vec->stream, sb);
  547. }
  548.  
  549. static void *
  550. opncls_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED,
  551.               void *addr ATTRIBUTE_UNUSED,
  552.               bfd_size_type len ATTRIBUTE_UNUSED,
  553.               int prot ATTRIBUTE_UNUSED,
  554.               int flags ATTRIBUTE_UNUSED,
  555.               file_ptr offset ATTRIBUTE_UNUSED,
  556.               void **map_addr ATTRIBUTE_UNUSED,
  557.               bfd_size_type *map_len ATTRIBUTE_UNUSED)
  558. {
  559.   return (void *) -1;
  560. }
  561.  
  562. static const struct bfd_iovec opncls_iovec = {
  563.   &opncls_bread, &opncls_bwrite, &opncls_btell, &opncls_bseek,
  564.   &opncls_bclose, &opncls_bflush, &opncls_bstat, &opncls_bmmap
  565. };
  566.  
  567. bfd *
  568. bfd_openr_iovec (const char *filename, const char *target,
  569.                  void *(*open_p) (struct bfd *, void *),
  570.                  void *open_closure,
  571.                  file_ptr (*pread_p) (struct bfd *, void *, void *,
  572.                                       file_ptr, file_ptr),
  573.                  int (*close_p) (struct bfd *, void *),
  574.                  int (*stat_p) (struct bfd *, void *, struct stat *))
  575. {
  576.   bfd *nbfd;
  577.   const bfd_target *target_vec;
  578.   struct opncls *vec;
  579.   void *stream;
  580.  
  581.   nbfd = _bfd_new_bfd ();
  582.   if (nbfd == NULL)
  583.     return NULL;
  584.  
  585.   target_vec = bfd_find_target (target, nbfd);
  586.   if (target_vec == NULL)
  587.     {
  588.       _bfd_delete_bfd (nbfd);
  589.       return NULL;
  590.     }
  591.  
  592.   /* PR 11983: Do not cache the original filename, but
  593.      rather make a copy - the original might go away.  */
  594.   nbfd->filename = xstrdup (filename);
  595.   nbfd->direction = read_direction;
  596.  
  597.   /* `open_p (...)' would get expanded by an the open(2) syscall macro.  */
  598.   stream = (*open_p) (nbfd, open_closure);
  599.   if (stream == NULL)
  600.     {
  601.       _bfd_delete_bfd (nbfd);
  602.       return NULL;
  603.     }
  604.  
  605.   vec = (struct opncls *) bfd_zalloc (nbfd, sizeof (struct opncls));
  606.   vec->stream = stream;
  607.   vec->pread = pread_p;
  608.   vec->close = close_p;
  609.   vec->stat = stat_p;
  610.  
  611.   nbfd->iovec = &opncls_iovec;
  612.   nbfd->iostream = vec;
  613.  
  614.   return nbfd;
  615. }
  617. /* bfd_openw -- open for writing.
  618.    Returns a pointer to a freshly-allocated BFD on success, or NULL.
  619.  
  620.    See comment by bfd_fdopenr before you try to modify this function.  */
  621.  
  622. /*
  623. FUNCTION
  624.         bfd_openw
  625.  
  626. SYNOPSIS
  627.         bfd *bfd_openw (const char *filename, const char *target);
  628.  
  629. DESCRIPTION
  630.         Create a BFD, associated with file @var{filename}, using the
  631.         file format @var{target}, and return a pointer to it.
  632.  
  633.         Possible errors are <<bfd_error_system_call>>, <<bfd_error_no_memory>>,
  634.         <<bfd_error_invalid_target>>.
  635.  
  636.         A copy of the @var{filename} argument is stored in the newly created
  637.         BFD.  It can be accessed via the bfd_get_filename() macro.
  638. */
  639.  
  640. bfd *
  641. bfd_openw (const char *filename, const char *target)
  642. {
  643.   bfd *nbfd;
  644.   const bfd_target *target_vec;
  645.  
  646.   /* nbfd has to point to head of malloc'ed block so that bfd_close may
  647.      reclaim it correctly.  */
  648.   nbfd = _bfd_new_bfd ();
  649.   if (nbfd == NULL)
  650.     return NULL;
  651.  
  652.   target_vec = bfd_find_target (target, nbfd);
  653.   if (target_vec == NULL)
  654.     {
  655.       _bfd_delete_bfd (nbfd);
  656.       return NULL;
  657.     }
  658.  
  659.   /* PR 11983: Do not cache the original filename, but
  660.      rather make a copy - the original might go away.  */
  661.   nbfd->filename = xstrdup (filename);
  662.   nbfd->direction = write_direction;
  663.  
  664.   if (bfd_open_file (nbfd) == NULL)
  665.     {
  666.       /* File not writeable, etc.  */
  667.       bfd_set_error (bfd_error_system_call);
  668.       _bfd_delete_bfd (nbfd);
  669.       return NULL;
  670.   }
  671.  
  672.   return nbfd;
  673. }
  674.  
  675. static inline void
  676. _maybe_make_executable (bfd * abfd)
  677. {
  678.   /* If the file was open for writing and is now executable,
  679.      make it so.  */
  680.   if (abfd->direction == write_direction
  681.       && (abfd->flags & (EXEC_P | DYNAMIC)) != 0)
  682.     {
  683.       struct stat buf;
  684.  
  685.       if (stat (abfd->filename, &buf) == 0
  686.           /* Do not attempt to change non-regular files.  This is
  687.              here especially for configure scripts and kernel builds
  688.              which run tests with "ld [...] -o /dev/null".  */
  689.           && S_ISREG(buf.st_mode))
  690.         {
  691. /*
  692.         unsigned int mask = umask (0);
  693.  
  694.         umask (mask);
  695.         chmod (abfd->filename,
  696.                  (0777
  697.                   & (buf.st_mode | ((S_IXUSR | S_IXGRP | S_IXOTH) &~ mask))));
  698. */
  699.         }
  700.     }
  701. }
  702.  
  703. /*
  704.  
  705. FUNCTION
  706.         bfd_close
  707.  
  708. SYNOPSIS
  709.         bfd_boolean bfd_close (bfd *abfd);
  710.  
  711. DESCRIPTION
  712.  
  713.         Close a BFD. If the BFD was open for writing, then pending
  714.         operations are completed and the file written out and closed.
  715.         If the created file is executable, then <<chmod>> is called
  716.         to mark it as such.
  717.  
  718.         All memory attached to the BFD is released.
  719.  
  720.         The file descriptor associated with the BFD is closed (even
  721.         if it was passed in to BFD by <<bfd_fdopenr>>).
  722.  
  723. RETURNS
  724.         <<TRUE>> is returned if all is ok, otherwise <<FALSE>>.
  725. */
  726.  
  727.  
  728. bfd_boolean
  729. bfd_close (bfd *abfd)
  730. {
  731.   bfd_boolean ret;
  732.  
  733.   if (bfd_write_p (abfd))
  734.     {
  735.       if (! BFD_SEND_FMT (abfd, _bfd_write_contents, (abfd)))
  736.         return FALSE;
  737.     }
  738.  
  739.   if (! BFD_SEND (abfd, _close_and_cleanup, (abfd)))
  740.     return FALSE;
  741.  
  742.   ret = abfd->iovec->bclose (abfd) == 0;
  743.  
  744.   if (ret)
  745.     _maybe_make_executable (abfd);
  746.  
  747.   _bfd_delete_bfd (abfd);
  748.  
  749.   return ret;
  750. }
  751.  
  752. /*
  753. FUNCTION
  754.         bfd_close_all_done
  755.  
  756. SYNOPSIS
  757.         bfd_boolean bfd_close_all_done (bfd *);
  758.  
  759. DESCRIPTION
  760.         Close a BFD.  Differs from <<bfd_close>> since it does not
  761.         complete any pending operations.  This routine would be used
  762.         if the application had just used BFD for swapping and didn't
  763.         want to use any of the writing code.
  764.  
  765.         If the created file is executable, then <<chmod>> is called
  766.         to mark it as such.
  767.  
  768.         All memory attached to the BFD is released.
  769.  
  770. RETURNS
  771.         <<TRUE>> is returned if all is ok, otherwise <<FALSE>>.
  772. */
  773.  
  774. bfd_boolean
  775. bfd_close_all_done (bfd *abfd)
  776. {
  777.   bfd_boolean ret;
  778.  
  779.   ret = bfd_cache_close (abfd);
  780.  
  781.   if (ret)
  782.     _maybe_make_executable (abfd);
  783.  
  784.   _bfd_delete_bfd (abfd);
  785.  
  786.   return ret;
  787. }
  788.  
  789. /*
  790. FUNCTION
  791.         bfd_create
  792.  
  793. SYNOPSIS
  794.         bfd *bfd_create (const char *filename, bfd *templ);
  795.  
  796. DESCRIPTION
  797.         Create a new BFD in the manner of <<bfd_openw>>, but without
  798.         opening a file. The new BFD takes the target from the target
  799.         used by @var{templ}. The format is always set to <<bfd_object>>.
  800.  
  801.         A copy of the @var{filename} argument is stored in the newly created
  802.         BFD.  It can be accessed via the bfd_get_filename() macro.
  803. */
  804.  
  805. bfd *
  806. bfd_create (const char *filename, bfd *templ)
  807. {
  808.   bfd *nbfd;
  809.  
  810.   nbfd = _bfd_new_bfd ();
  811.   if (nbfd == NULL)
  812.     return NULL;
  813.   /* PR 11983: Do not cache the original filename, but
  814.      rather make a copy - the original might go away.  */
  815.   nbfd->filename = xstrdup (filename);
  816.   if (templ)
  817.     nbfd->xvec = templ->xvec;
  818.   nbfd->direction = no_direction;
  819.   bfd_set_format (nbfd, bfd_object);
  820.  
  821.   return nbfd;
  822. }
  823.  
  824. /*
  825. FUNCTION
  826.         bfd_make_writable
  827.  
  828. SYNOPSIS
  829.         bfd_boolean bfd_make_writable (bfd *abfd);
  830.  
  831. DESCRIPTION
  832.         Takes a BFD as created by <<bfd_create>> and converts it
  833.         into one like as returned by <<bfd_openw>>.  It does this
  834.         by converting the BFD to BFD_IN_MEMORY.  It's assumed that
  835.         you will call <<bfd_make_readable>> on this bfd later.
  836.  
  837. RETURNS
  838.         <<TRUE>> is returned if all is ok, otherwise <<FALSE>>.
  839. */
  840.  
  841. bfd_boolean
  842. bfd_make_writable (bfd *abfd)
  843. {
  844.   struct bfd_in_memory *bim;
  845.  
  846.   if (abfd->direction != no_direction)
  847.     {
  848.       bfd_set_error (bfd_error_invalid_operation);
  849.       return FALSE;
  850.     }
  851.  
  852.   bim = (struct bfd_in_memory *) bfd_malloc (sizeof (struct bfd_in_memory));
  853.   if (bim == NULL)
  854.     return FALSE;       /* bfd_error already set.  */
  855.   abfd->iostream = bim;
  856.   /* bfd_bwrite will grow these as needed.  */
  857.   bim->size = 0;
  858.   bim->buffer = 0;
  859.  
  860.   abfd->flags |= BFD_IN_MEMORY;
  861.   abfd->iovec = &_bfd_memory_iovec;
  862.   abfd->origin = 0;
  863.   abfd->direction = write_direction;
  864.   abfd->where = 0;
  865.  
  866.   return TRUE;
  867. }
  868.  
  869. /*
  870. FUNCTION
  871.         bfd_make_readable
  872.  
  873. SYNOPSIS
  874.         bfd_boolean bfd_make_readable (bfd *abfd);
  875.  
  876. DESCRIPTION
  877.         Takes a BFD as created by <<bfd_create>> and
  878.         <<bfd_make_writable>> and converts it into one like as
  879.         returned by <<bfd_openr>>.  It does this by writing the
  880.         contents out to the memory buffer, then reversing the
  881.         direction.
  882.  
  883. RETURNS
  884.         <<TRUE>> is returned if all is ok, otherwise <<FALSE>>.  */
  885.  
  886. bfd_boolean
  887. bfd_make_readable (bfd *abfd)
  888. {
  889.   if (abfd->direction != write_direction || !(abfd->flags & BFD_IN_MEMORY))
  890.     {
  891.       bfd_set_error (bfd_error_invalid_operation);
  892.       return FALSE;
  893.     }
  894.  
  895.   if (! BFD_SEND_FMT (abfd, _bfd_write_contents, (abfd)))
  896.     return FALSE;
  897.  
  898.   if (! BFD_SEND (abfd, _close_and_cleanup, (abfd)))
  899.     return FALSE;
  900.  
  901.   abfd->arch_info = &bfd_default_arch_struct;
  902.  
  903.   abfd->where = 0;
  904.   abfd->format = bfd_unknown;
  905.   abfd->my_archive = NULL;
  906.   abfd->origin = 0;
  907.   abfd->opened_once = FALSE;
  908.   abfd->output_has_begun = FALSE;
  909.   abfd->section_count = 0;
  910.   abfd->usrdata = NULL;
  911.   abfd->cacheable = FALSE;
  912.   abfd->flags |= BFD_IN_MEMORY;
  913.   abfd->mtime_set = FALSE;
  914.  
  915.   abfd->target_defaulted = TRUE;
  916.   abfd->direction = read_direction;
  917.   abfd->sections = 0;
  918.   abfd->symcount = 0;
  919.   abfd->outsymbols = 0;
  920.   abfd->tdata.any = 0;
  921.  
  922.   bfd_section_list_clear (abfd);
  923.   bfd_check_format (abfd, bfd_object);
  924.  
  925.   return TRUE;
  926. }
  927.  
  928. /*
  929. FUNCTION
  930.         bfd_alloc
  931.  
  932. SYNOPSIS
  933.         void *bfd_alloc (bfd *abfd, bfd_size_type wanted);
  934.  
  935. DESCRIPTION
  936.         Allocate a block of @var{wanted} bytes of memory attached to
  937.         <<abfd>> and return a pointer to it.
  938. */
  939.  
  940. void *
  941. bfd_alloc (bfd *abfd, bfd_size_type size)
  942. {
  943.   void *ret;
  944.   unsigned long ul_size = (unsigned long) size;
  945.  
  946.   if (size != ul_size
  947.       /* Note - although objalloc_alloc takes an unsigned long as its
  948.          argument, internally the size is treated as a signed long.  This can
  949.          lead to problems where, for example, a request to allocate -1 bytes
  950.          can result in just 1 byte being allocated, rather than
  951.          ((unsigned long) -1) bytes.  Also memory checkers will often
  952.          complain about attempts to allocate a negative amount of memory.
  953.          So to stop these problems we fail if the size is negative.  */
  954.       || ((signed long) ul_size) < 0)
  955.     {
  956.       bfd_set_error (bfd_error_no_memory);
  957.       return NULL;
  958.     }
  959.  
  960.   ret = objalloc_alloc ((struct objalloc *) abfd->memory, ul_size);
  961.   if (ret == NULL)
  962.     bfd_set_error (bfd_error_no_memory);
  963.   return ret;
  964. }
  965.  
  966. /*
  967. INTERNAL_FUNCTION
  968.         bfd_alloc2
  969.  
  970. SYNOPSIS
  971.         void *bfd_alloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size);
  972.  
  973. DESCRIPTION
  974.         Allocate a block of @var{nmemb} elements of @var{size} bytes each
  975.         of memory attached to <<abfd>> and return a pointer to it.
  976. */
  977.  
  978. void *
  979. bfd_alloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size)
  980. {
  981.   if ((nmemb | size) >= HALF_BFD_SIZE_TYPE
  982.       && size != 0
  983.       && nmemb > ~(bfd_size_type) 0 / size)
  984.     {
  985.       bfd_set_error (bfd_error_no_memory);
  986.       return NULL;
  987.     }
  988.  
  989.   return bfd_alloc (abfd, size * nmemb);
  990. }
  991.  
  992. /*
  993. FUNCTION
  994.         bfd_zalloc
  995.  
  996. SYNOPSIS
  997.         void *bfd_zalloc (bfd *abfd, bfd_size_type wanted);
  998.  
  999. DESCRIPTION
  1000.         Allocate a block of @var{wanted} bytes of zeroed memory
  1001.         attached to <<abfd>> and return a pointer to it.
  1002. */
  1003.  
  1004. void *
  1005. bfd_zalloc (bfd *abfd, bfd_size_type size)
  1006. {
  1007.   void *res;
  1008.  
  1009.   res = bfd_alloc (abfd, size);
  1010.   if (res)
  1011.     memset (res, 0, (size_t) size);
  1012.   return res;
  1013. }
  1014.  
  1015. /*
  1016. INTERNAL_FUNCTION
  1017.         bfd_zalloc2
  1018.  
  1019. SYNOPSIS
  1020.         void *bfd_zalloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size);
  1021.  
  1022. DESCRIPTION
  1023.         Allocate a block of @var{nmemb} elements of @var{size} bytes each
  1024.         of zeroed memory attached to <<abfd>> and return a pointer to it.
  1025. */
  1026.  
  1027. void *
  1028. bfd_zalloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size)
  1029. {
  1030.   void *res;
  1031.  
  1032.   if ((nmemb | size) >= HALF_BFD_SIZE_TYPE
  1033.       && size != 0
  1034.       && nmemb > ~(bfd_size_type) 0 / size)
  1035.     {
  1036.       bfd_set_error (bfd_error_no_memory);
  1037.       return NULL;
  1038.     }
  1039.  
  1040.   size *= nmemb;
  1041.  
  1042.   res = bfd_alloc (abfd, size);
  1043.   if (res)
  1044.     memset (res, 0, (size_t) size);
  1045.   return res;
  1046. }
  1047.  
  1048. /* Free a block allocated for a BFD.
  1049.    Note:  Also frees all more recently allocated blocks!  */
  1050.  
  1051. void
  1052. bfd_release (bfd *abfd, void *block)
  1053. {
  1054.   objalloc_free_block ((struct objalloc *) abfd->memory, block);
  1055. }
  1056.  
  1057.  
  1058. /*
  1059.    GNU Extension: separate debug-info files
  1060.  
  1061.    The idea here is that a special section called .gnu_debuglink might be
  1062.    embedded in a binary file, which indicates that some *other* file
  1063.    contains the real debugging information. This special section contains a
  1064.    filename and CRC32 checksum, which we read and resolve to another file,
  1065.    if it exists.
  1066.  
  1067.    This facilitates "optional" provision of debugging information, without
  1068.    having to provide two complete copies of every binary object (with and
  1069.    without debug symbols).  */
  1070.  
  1071. #define GNU_DEBUGLINK           ".gnu_debuglink"
  1072. #define GNU_DEBUGALTLINK        ".gnu_debugaltlink"
  1073.  
  1074. /*
  1075. FUNCTION
  1076.         bfd_calc_gnu_debuglink_crc32
  1077.  
  1078. SYNOPSIS
  1079.         unsigned long bfd_calc_gnu_debuglink_crc32
  1080.           (unsigned long crc, const unsigned char *buf, bfd_size_type len);
  1081.  
  1082. DESCRIPTION
  1083.         Computes a CRC value as used in the .gnu_debuglink section.
  1084.         Advances the previously computed @var{crc} value by computing
  1085.         and adding in the crc32 for @var{len} bytes of @var{buf}.
  1086.  
  1087. RETURNS
  1088.         Return the updated CRC32 value.
  1089. */
  1090.  
  1091. unsigned long
  1092. bfd_calc_gnu_debuglink_crc32 (unsigned long crc,
  1093.                               const unsigned char *buf,
  1094.                               bfd_size_type len)
  1095. {
  1096.   static const unsigned long crc32_table[256] =
  1097.     {
  1098.       0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
  1099.       0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
  1100.       0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
  1101.       0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
  1102.       0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
  1103.       0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
  1104.       0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
  1105.       0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  1106.       0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
  1107.       0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
  1108.       0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
  1109.       0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
  1110.       0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
  1111.       0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
  1112.       0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
  1113.       0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  1114.       0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
  1115.       0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
  1116.       0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
  1117.       0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
  1118.       0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
  1119.       0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
  1120.       0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
  1121.       0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  1122.       0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
  1123.       0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
  1124.       0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
  1125.       0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
  1126.       0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
  1127.       0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
  1128.       0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
  1129.       0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  1130.       0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
  1131.       0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
  1132.       0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
  1133.       0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
  1134.       0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
  1135.       0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
  1136.       0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
  1137.       0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  1138.       0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
  1139.       0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
  1140.       0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
  1141.       0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
  1142.       0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
  1143.       0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
  1144.       0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
  1145.       0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  1146.       0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
  1147.       0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
  1148.       0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
  1149.       0x2d02ef8d
  1150.     };
  1151.   const unsigned char *end;
  1152.  
  1153.   crc = ~crc & 0xffffffff;
  1154.   for (end = buf + len; buf < end; ++ buf)
  1155.     crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
  1156.   return ~crc & 0xffffffff;
  1157. }
  1158.  
  1159.  
  1160. /*
  1161. FUNCTION
  1162.         bfd_get_debug_link_info
  1163.  
  1164. SYNOPSIS
  1165.         char *bfd_get_debug_link_info (bfd *abfd, unsigned long *crc32_out);
  1166.  
  1167. DESCRIPTION
  1168.         Fetch the filename and CRC32 value for any separate debuginfo
  1169.         associated with @var{abfd}. Return NULL if no such info found,
  1170.         otherwise return filename and update @var{crc32_out}.  The
  1171.         returned filename is allocated with @code{malloc}; freeing it
  1172.         is the responsibility of the caller.
  1173. */
  1174.  
  1175. char *
  1176. bfd_get_debug_link_info (bfd *abfd, unsigned long *crc32_out)
  1177. {
  1178.   asection *sect;
  1179.   unsigned long crc32;
  1180.   bfd_byte *contents;
  1181.   unsigned int crc_offset;
  1182.   char *name;
  1183.  
  1184.   BFD_ASSERT (abfd);
  1185.   BFD_ASSERT (crc32_out);
  1186.  
  1187.   sect = bfd_get_section_by_name (abfd, GNU_DEBUGLINK);
  1188.  
  1189.   if (sect == NULL)
  1190.     return NULL;
  1191.  
  1192.   if (!bfd_malloc_and_get_section (abfd, sect, &contents))
  1193.     {
  1194.       if (contents != NULL)
  1195.         free (contents);
  1196.       return NULL;
  1197.     }
  1198.  
  1199.   /* CRC value is stored after the filename, aligned up to 4 bytes.  */
  1200.   name = (char *) contents;
  1201.   /* PR 17597: avoid reading off the end of the buffer.  */
  1202.   crc_offset = strnlen (name, bfd_get_section_size (sect)) + 1;
  1203.   crc_offset = (crc_offset + 3) & ~3;
  1204.   if (crc_offset >= bfd_get_section_size (sect))
  1205.     return NULL;
  1206.  
  1207.   crc32 = bfd_get_32 (abfd, contents + crc_offset);
  1208.  
  1209.   *crc32_out = crc32;
  1210.   return name;
  1211. }
  1212.  
  1213. /*
  1214. FUNCTION
  1215.         bfd_get_alt_debug_link_info
  1216.  
  1217. SYNOPSIS
  1218.         char *bfd_get_alt_debug_link_info (bfd * abfd,
  1219.                                            bfd_size_type *buildid_len,
  1220.                                            bfd_byte **buildid_out);
  1221.  
  1222. DESCRIPTION
  1223.         Fetch the filename and BuildID value for any alternate debuginfo
  1224.         associated with @var{abfd}.  Return NULL if no such info found,
  1225.         otherwise return filename and update @var{buildid_len} and
  1226.         @var{buildid_out}.  The returned filename and build_id are
  1227.         allocated with @code{malloc}; freeing them is the
  1228.         responsibility of the caller.
  1229. */
  1230.  
  1231. char *
  1232. bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
  1233.                              bfd_byte **buildid_out)
  1234. {
  1235.   asection *sect;
  1236.   bfd_byte *contents;
  1237.   unsigned int buildid_offset;
  1238.   char *name;
  1239.  
  1240.   BFD_ASSERT (abfd);
  1241.   BFD_ASSERT (buildid_len);
  1242.   BFD_ASSERT (buildid_out);
  1243.  
  1244.   sect = bfd_get_section_by_name (abfd, GNU_DEBUGALTLINK);
  1245.  
  1246.   if (sect == NULL)
  1247.     return NULL;
  1248.  
  1249.   if (!bfd_malloc_and_get_section (abfd, sect, & contents))
  1250.     {
  1251.       if (contents != NULL)
  1252.         free (contents);
  1253.       return NULL;
  1254.     }
  1255.  
  1256.   /* BuildID value is stored after the filename.  */
  1257.   name = (char *) contents;
  1258.   buildid_offset = strnlen (name, bfd_get_section_size (sect)) + 1;
  1259.   if (buildid_offset >= bfd_get_section_size (sect))
  1260.     return NULL;
  1261.  
  1262.   *buildid_len = bfd_get_section_size (sect) - buildid_offset;
  1263.   *buildid_out = bfd_malloc (*buildid_len);
  1264.   memcpy (*buildid_out, contents + buildid_offset, *buildid_len);
  1265.  
  1266.   return name;
  1267. }
  1268.  
  1269. /*
  1270. INTERNAL_FUNCTION
  1271.         separate_debug_file_exists
  1272.  
  1273. SYNOPSIS
  1274.         bfd_boolean separate_debug_file_exists
  1275.           (char *name, unsigned long crc32);
  1276.  
  1277. DESCRIPTION
  1278.         Checks to see if @var{name} is a file and if its contents
  1279.         match @var{crc32}.
  1280. */
  1281.  
  1282. static bfd_boolean
  1283. separate_debug_file_exists (const char *name, const unsigned long crc)
  1284. {
  1285.   static unsigned char buffer [8 * 1024];
  1286.   unsigned long file_crc = 0;
  1287.   FILE *f;
  1288.   bfd_size_type count;
  1289.  
  1290.   BFD_ASSERT (name);
  1291.  
  1292.   f = real_fopen (name, FOPEN_RB);
  1293.   if (f == NULL)
  1294.     return FALSE;
  1295.  
  1296.   while ((count = fread (buffer, 1, sizeof (buffer), f)) > 0)
  1297.     file_crc = bfd_calc_gnu_debuglink_crc32 (file_crc, buffer, count);
  1298.  
  1299.   fclose (f);
  1300.  
  1301.   return crc == file_crc;
  1302. }
  1303.  
  1304. /*
  1305. INTERNAL_FUNCTION
  1306.         separate_alt_debug_file_exists
  1307.  
  1308. SYNOPSIS
  1309.         bfd_boolean separate_alt_debug_file_exists
  1310.           (char *name, unsigned long crc32);
  1311.  
  1312. DESCRIPTION
  1313.         Checks to see if @var{name} is a file and if its BuildID
  1314.         matches @var{buildid}.
  1315. */
  1316.  
  1317. static bfd_boolean
  1318. separate_alt_debug_file_exists (const char *name,
  1319.                                 const unsigned long buildid ATTRIBUTE_UNUSED)
  1320. {
  1321.   FILE *f;
  1322.  
  1323.   BFD_ASSERT (name);
  1324.  
  1325.   f = real_fopen (name, FOPEN_RB);
  1326.   if (f == NULL)
  1327.     return FALSE;
  1328.  
  1329.   /* FIXME: Add code to check buildid.  */
  1330.  
  1331.   fclose (f);
  1332.  
  1333.   return TRUE;
  1334. }
  1335.  
  1336. /*
  1337. INTERNAL_FUNCTION
  1338.         find_separate_debug_file
  1339.  
  1340. SYNOPSIS
  1341.         char *find_separate_debug_file (bfd *abfd);
  1342.  
  1343. DESCRIPTION
  1344.         Searches @var{abfd} for a section called @var{section_name} which
  1345.         is expected to contain a reference to a file containing separate
  1346.         debugging information.  The function scans various locations in
  1347.         the filesystem, including the file tree rooted at
  1348.         @var{debug_file_directory}, and returns the first matching
  1349.         filename that it finds.  If @var{check_crc} is TRUE then the
  1350.         contents of the file must also match the CRC value contained in
  1351.         @var{section_name}.  Returns NULL if no valid file could be found.
  1352. */
  1353.  
  1354. typedef char *      (* get_func_type) (bfd *, unsigned long *);
  1355. typedef bfd_boolean (* check_func_type) (const char *, const unsigned long);
  1356.  
  1357. static char *
  1358. find_separate_debug_file (bfd *           abfd,
  1359.                           const char *    debug_file_directory,
  1360.                           get_func_type   get_func,
  1361.                           check_func_type check_func)
  1362. {
  1363.   char *base;
  1364.   char *dir;
  1365.   char *debugfile;
  1366.   char *canon_dir;
  1367.   unsigned long crc32;
  1368.   size_t dirlen;
  1369.   size_t canon_dirlen;
  1370.  
  1371.   BFD_ASSERT (abfd);
  1372.   if (debug_file_directory == NULL)
  1373.     debug_file_directory = ".";
  1374.  
  1375.   /* BFD may have been opened from a stream.  */
  1376.   if (abfd->filename == NULL)
  1377.     {
  1378.       bfd_set_error (bfd_error_invalid_operation);
  1379.       return NULL;
  1380.     }
  1381.  
  1382.   base = get_func (abfd, & crc32);
  1383.    
  1384.   if (base == NULL)
  1385.     return NULL;
  1386.  
  1387.   if (base[0] == '\0')
  1388.     {
  1389.       free (base);
  1390.       bfd_set_error (bfd_error_no_debug_section);
  1391.       return NULL;
  1392.     }
  1393.  
  1394.   for (dirlen = strlen (abfd->filename); dirlen > 0; dirlen--)
  1395.     if (IS_DIR_SEPARATOR (abfd->filename[dirlen - 1]))
  1396.       break;
  1397.  
  1398.   dir = (char *) bfd_malloc (dirlen + 1);
  1399.   if (dir == NULL)
  1400.     {
  1401.       free (base);
  1402.       return NULL;
  1403.     }
  1404.   memcpy (dir, abfd->filename, dirlen);
  1405.   dir[dirlen] = '\0';
  1406.  
  1407.   /* Compute the canonical name of the bfd object with all symbolic links
  1408.      resolved, for use in the global debugfile directory.  */
  1409.   canon_dir = lrealpath (abfd->filename);
  1410.   for (canon_dirlen = strlen (canon_dir); canon_dirlen > 0; canon_dirlen--)
  1411.     if (IS_DIR_SEPARATOR (canon_dir[canon_dirlen - 1]))
  1412.       break;
  1413.   canon_dir[canon_dirlen] = '\0';
  1414.  
  1415.   debugfile = (char *)
  1416.       bfd_malloc (strlen (debug_file_directory) + 1
  1417.                   + (canon_dirlen > dirlen ? canon_dirlen : dirlen)
  1418.                   + strlen (".debug/")
  1419.                   + strlen (base)
  1420.                   + 1);
  1421.   if (debugfile == NULL)
  1422.     goto found; /* Actually this returns NULL.  */
  1423.  
  1424.   /* First try in the same directory as the original file:  */
  1425.   strcpy (debugfile, dir);
  1426.   strcat (debugfile, base);
  1427.  
  1428.   if (check_func (debugfile, crc32))
  1429.     goto found;
  1430.  
  1431.   /* Then try in a subdirectory called .debug.  */
  1432.   strcpy (debugfile, dir);
  1433.   strcat (debugfile, ".debug/");
  1434.   strcat (debugfile, base);
  1435.  
  1436.   if (check_func (debugfile, crc32))
  1437.     goto found;
  1438.  
  1439.   /* Then try in the global debugfile directory.  */
  1440.   strcpy (debugfile, debug_file_directory);
  1441.   dirlen = strlen (debug_file_directory) - 1;
  1442.   if (dirlen > 0
  1443.       && debug_file_directory[dirlen] != '/'
  1444.       && canon_dir[0] != '/')
  1445.     strcat (debugfile, "/");
  1446.   strcat (debugfile, canon_dir);
  1447.   strcat (debugfile, base);
  1448.  
  1449.   if (check_func (debugfile, crc32))
  1450.     goto found;
  1451.  
  1452.   /* Failed to find the file.  */
  1453.   free (debugfile);
  1454.   debugfile = NULL;
  1455.  
  1456.  found:
  1457.   free (base);
  1458.   free (dir);
  1459.   free (canon_dir);
  1460.   return debugfile;
  1461. }
  1462.  
  1463.  
  1464. /*
  1465. FUNCTION
  1466.         bfd_follow_gnu_debuglink
  1467.  
  1468. SYNOPSIS
  1469.         char *bfd_follow_gnu_debuglink (bfd *abfd, const char *dir);
  1470.  
  1471. DESCRIPTION
  1472.  
  1473.         Takes a BFD and searches it for a .gnu_debuglink section.  If this
  1474.         section is found, it examines the section for the name and checksum
  1475.         of a '.debug' file containing auxiliary debugging information.  It
  1476.         then searches the filesystem for this .debug file in some standard
  1477.         locations, including the directory tree rooted at @var{dir}, and if
  1478.         found returns the full filename.
  1479.  
  1480.         If @var{dir} is NULL, it will search a default path configured into
  1481.         libbfd at build time.  [XXX this feature is not currently
  1482.         implemented].
  1483.  
  1484. RETURNS
  1485.         <<NULL>> on any errors or failure to locate the .debug file,
  1486.         otherwise a pointer to a heap-allocated string containing the
  1487.         filename.  The caller is responsible for freeing this string.
  1488. */
  1489.  
  1490. char *
  1491. bfd_follow_gnu_debuglink (bfd *abfd, const char *dir)
  1492. {
  1493.   return find_separate_debug_file (abfd, dir,
  1494.                                    bfd_get_debug_link_info,
  1495.                                    separate_debug_file_exists);
  1496. }
  1497.  
  1498. /* Helper for bfd_follow_gnu_debugaltlink.  It just pretends to return
  1499.    a CRC.  .gnu_debugaltlink supplies a build-id, which is different,
  1500.    but this is ok because separate_alt_debug_file_exists ignores the
  1501.    CRC anyway.  */
  1502.  
  1503. static char *
  1504. get_alt_debug_link_info_shim (bfd * abfd, unsigned long *crc32_out)
  1505. {
  1506.   bfd_size_type len;
  1507.   bfd_byte *buildid = NULL;
  1508.   char *result = bfd_get_alt_debug_link_info (abfd, &len, &buildid);
  1509.  
  1510.   *crc32_out = 0;
  1511.   free (buildid);
  1512.  
  1513.   return result;
  1514. }
  1515.  
  1516. /*
  1517. FUNCTION
  1518.         bfd_follow_gnu_debugaltlink
  1519.  
  1520. SYNOPSIS
  1521.         char *bfd_follow_gnu_debugaltlink (bfd *abfd, const char *dir);
  1522.  
  1523. DESCRIPTION
  1524.  
  1525.         Takes a BFD and searches it for a .gnu_debugaltlink section.  If this
  1526.         section is found, it examines the section for the name of a file
  1527.         containing auxiliary debugging information.  It then searches the
  1528.         filesystem for this file in a set of standard locations, including
  1529.         the directory tree rooted at @var{dir}, and if found returns the
  1530.         full filename.
  1531.  
  1532.         If @var{dir} is NULL, it will search a default path configured into
  1533.         libbfd at build time.  [FIXME: This feature is not currently
  1534.         implemented].
  1535.  
  1536. RETURNS
  1537.         <<NULL>> on any errors or failure to locate the debug file,
  1538.         otherwise a pointer to a heap-allocated string containing the
  1539.         filename.  The caller is responsible for freeing this string.
  1540. */
  1541.  
  1542. char *
  1543. bfd_follow_gnu_debugaltlink (bfd *abfd, const char *dir)
  1544. {
  1545.   return find_separate_debug_file (abfd, dir,
  1546.                                    get_alt_debug_link_info_shim,
  1547.                                    separate_alt_debug_file_exists);
  1548. }
  1549.  
  1550. /*
  1551. FUNCTION
  1552.         bfd_create_gnu_debuglink_section
  1553.  
  1554. SYNOPSIS
  1555.         struct bfd_section *bfd_create_gnu_debuglink_section
  1556.           (bfd *abfd, const char *filename);
  1557.  
  1558. DESCRIPTION
  1559.  
  1560.         Takes a @var{BFD} and adds a .gnu_debuglink section to it.  The section is sized
  1561.         to be big enough to contain a link to the specified @var{filename}.
  1562.  
  1563. RETURNS
  1564.         A pointer to the new section is returned if all is ok.  Otherwise <<NULL>> is
  1565.         returned and bfd_error is set.
  1566. */
  1567.  
  1568. asection *
  1569. bfd_create_gnu_debuglink_section (bfd *abfd, const char *filename)
  1570. {
  1571.   asection *sect;
  1572.   bfd_size_type debuglink_size;
  1573.   flagword flags;
  1574.  
  1575.   if (abfd == NULL || filename == NULL)
  1576.     {
  1577.       bfd_set_error (bfd_error_invalid_operation);
  1578.       return NULL;
  1579.     }
  1580.  
  1581.   /* Strip off any path components in filename.  */
  1582.   filename = lbasename (filename);
  1583.  
  1584.   sect = bfd_get_section_by_name (abfd, GNU_DEBUGLINK);
  1585.   if (sect)
  1586.     {
  1587.       /* Section already exists.  */
  1588.       bfd_set_error (bfd_error_invalid_operation);
  1589.       return NULL;
  1590.     }
  1591.  
  1592.   flags = SEC_HAS_CONTENTS | SEC_READONLY | SEC_DEBUGGING;
  1593.   sect = bfd_make_section_with_flags (abfd, GNU_DEBUGLINK, flags);
  1594.   if (sect == NULL)
  1595.     return NULL;
  1596.  
  1597.   debuglink_size = strlen (filename) + 1;
  1598.   debuglink_size += 3;
  1599.   debuglink_size &= ~3;
  1600.   debuglink_size += 4;
  1601.  
  1602.   if (! bfd_set_section_size (abfd, sect, debuglink_size))
  1603.     /* XXX Should we delete the section from the bfd ?  */
  1604.     return NULL;
  1605.  
  1606.   return sect;
  1607. }
  1608.  
  1609.  
  1610. /*
  1611. FUNCTION
  1612.         bfd_fill_in_gnu_debuglink_section
  1613.  
  1614. SYNOPSIS
  1615.         bfd_boolean bfd_fill_in_gnu_debuglink_section
  1616.           (bfd *abfd, struct bfd_section *sect, const char *filename);
  1617.  
  1618. DESCRIPTION
  1619.  
  1620.         Takes a @var{BFD} and containing a .gnu_debuglink section @var{SECT}
  1621.         and fills in the contents of the section to contain a link to the
  1622.         specified @var{filename}.  The filename should be relative to the
  1623.         current directory.
  1624.  
  1625. RETURNS
  1626.         <<TRUE>> is returned if all is ok.  Otherwise <<FALSE>> is returned
  1627.         and bfd_error is set.
  1628. */
  1629.  
  1630. bfd_boolean
  1631. bfd_fill_in_gnu_debuglink_section (bfd *abfd,
  1632.                                    struct bfd_section *sect,
  1633.                                    const char *filename)
  1634. {
  1635.   bfd_size_type debuglink_size;
  1636.   unsigned long crc32;
  1637.   char * contents;
  1638.   bfd_size_type crc_offset;
  1639.   FILE * handle;
  1640.   static unsigned char buffer[8 * 1024];
  1641.   size_t count;
  1642.   size_t filelen;
  1643.  
  1644.   if (abfd == NULL || sect == NULL || filename == NULL)
  1645.     {
  1646.       bfd_set_error (bfd_error_invalid_operation);
  1647.       return FALSE;
  1648.     }
  1649.  
  1650.   /* Make sure that we can read the file.
  1651.      XXX - Should we attempt to locate the debug info file using the same
  1652.      algorithm as gdb ?  At the moment, since we are creating the
  1653.      .gnu_debuglink section, we insist upon the user providing us with a
  1654.      correct-for-section-creation-time path, but this need not conform to
  1655.      the gdb location algorithm.  */
  1656.   handle = real_fopen (filename, FOPEN_RB);
  1657.   if (handle == NULL)
  1658.     {
  1659.       bfd_set_error (bfd_error_system_call);
  1660.       return FALSE;
  1661.     }
  1662.  
  1663.   crc32 = 0;
  1664.   while ((count = fread (buffer, 1, sizeof buffer, handle)) > 0)
  1665.     crc32 = bfd_calc_gnu_debuglink_crc32 (crc32, buffer, count);
  1666.   fclose (handle);
  1667.  
  1668.   /* Strip off any path components in filename,
  1669.      now that we no longer need them.  */
  1670.   filename = lbasename (filename);
  1671.  
  1672.   filelen = strlen (filename);
  1673.   debuglink_size = filelen + 1;
  1674.   debuglink_size += 3;
  1675.   debuglink_size &= ~3;
  1676.   debuglink_size += 4;
  1677.  
  1678.   contents = (char *) bfd_malloc (debuglink_size);
  1679.   if (contents == NULL)
  1680.     {
  1681.       /* XXX Should we delete the section from the bfd ?  */
  1682.       return FALSE;
  1683.     }
  1684.  
  1685.   crc_offset = debuglink_size - 4;
  1686.   memcpy (contents, filename, filelen);
  1687.   memset (contents + filelen, 0, crc_offset - filelen);
  1688.  
  1689.   bfd_put_32 (abfd, crc32, contents + crc_offset);
  1690.  
  1691.   if (! bfd_set_section_contents (abfd, sect, contents, 0, debuglink_size))
  1692.     {
  1693.       /* XXX Should we delete the section from the bfd ?  */
  1694.       free (contents);
  1695.       return FALSE;
  1696.     }
  1697.  
  1698.   return TRUE;
  1699. }
  1700.