GDB 7.6.50

gdb/gdb_bfd.c

Index: gdb/gdb_bfd.c
diff --git a/gdb/gdb_bfd.c b/gdb/gdb_bfd.c
new file mode 100644
index 0000000000000000000000000000000000000000..2beeb5dea3e65a7bc29f82a316a4830b98fb8c9c
--- /dev/null
+++ b/gdb/gdb_bfd.c
@@ -0,0 +1,721 @@
+/* Definitions for BFD wrappers used by GDB.
+
+   Copyright (C) 2011-2013 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "gdb_bfd.h"
+#include "gdb_assert.h"
+#include <string.h>
+#include "ui-out.h"
+#include "gdbcmd.h"
+#include "hashtab.h"
+#include "filestuff.h"
+#ifdef HAVE_ZLIB_H
+#include <zlib.h>
+#endif
+#ifdef HAVE_MMAP
+#include <sys/mman.h>
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *) -1)
+#endif
+#endif
+
+/* An object of this type is stored in the section's user data when
+   mapping a section.  */
+
+struct gdb_bfd_section_data
+{
+  /* Size of the data.  */
+  bfd_size_type size;
+  /* If the data was mmapped, this is the length of the map.  */
+  bfd_size_type map_len;
+  /* The data.  If NULL, the section data has not been read.  */
+  void *data;
+  /* If the data was mmapped, this is the map address.  */
+  void *map_addr;
+};
+
+/* A hash table holding every BFD that gdb knows about.  This is not
+   to be confused with 'gdb_bfd_cache', which is used for sharing
+   BFDs; in contrast, this hash is used just to implement
+   "maint info bfd".  */
+
+static htab_t all_bfds;
+
+/* See gdb_bfd.h.  */
+
+void
+gdb_bfd_stash_filename (struct bfd *abfd)
+{
+  char *name = bfd_get_filename (abfd);
+  char *data;
+
+  data = bfd_alloc (abfd, strlen (name) + 1);
+  strcpy (data, name);
+
+  /* Unwarranted chumminess with BFD.  */
+  abfd->filename = data;
+}
+
+/* An object of this type is stored in each BFD's user data.  */
+
+struct gdb_bfd_data
+{
+  /* The reference count.  */
+  int refc;
+
+  /* The mtime of the BFD at the point the cache entry was made.  */
+  time_t mtime;
+
+  /* This is true if we have determined whether this BFD has any
+     sections requiring relocation.  */
+  unsigned int relocation_computed : 1;
+
+  /* This is true if any section needs relocation.  */
+  unsigned int needs_relocations : 1;
+
+  /* This is true if we have successfully computed the file's CRC.  */
+  unsigned int crc_computed : 1;
+
+  /* The file's CRC.  */
+  unsigned long crc;
+
+  /* If the BFD comes from an archive, this points to the archive's
+     BFD.  Otherwise, this is NULL.  */
+  bfd *archive_bfd;
+
+  /* The registry.  */
+  REGISTRY_FIELDS;
+};
+
+#define GDB_BFD_DATA_ACCESSOR(ABFD) \
+  ((struct gdb_bfd_data *) bfd_usrdata (ABFD))
+
+DEFINE_REGISTRY (bfd, GDB_BFD_DATA_ACCESSOR)
+
+/* A hash table storing all the BFDs maintained in the cache.  */
+
+static htab_t gdb_bfd_cache;
+
+/* The type of an object being looked up in gdb_bfd_cache.  We use
+   htab's capability of storing one kind of object (BFD in this case)
+   and using a different sort of object for searching.  */
+
+struct gdb_bfd_cache_search
+{
+  /* The filename.  */
+  const char *filename;
+  /* The mtime.  */
+  time_t mtime;
+};
+
+/* A hash function for BFDs.  */
+
+static hashval_t
+hash_bfd (const void *b)
+{
+  const bfd *abfd = b;
+
+  /* It is simplest to just hash the filename.  */
+  return htab_hash_string (bfd_get_filename (abfd));
+}
+
+/* An equality function for BFDs.  Note that this expects the caller
+   to search using struct gdb_bfd_cache_search only, not BFDs.  */
+
+static int
+eq_bfd (const void *a, const void *b)
+{
+  const bfd *abfd = a;
+  const struct gdb_bfd_cache_search *s = b;
+  struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
+
+  return (gdata->mtime == s->mtime
+	  && strcmp (bfd_get_filename (abfd), s->filename) == 0);
+}
+
+/* See gdb_bfd.h.  */
+
+struct bfd *
+gdb_bfd_open (const char *name, const char *target, int fd)
+{
+  hashval_t hash;
+  void **slot;
+  bfd *abfd;
+  struct gdb_bfd_cache_search search;
+  struct stat st;
+
+  if (gdb_bfd_cache == NULL)
+    gdb_bfd_cache = htab_create_alloc (1, hash_bfd, eq_bfd, NULL,
+				       xcalloc, xfree);
+
+  if (fd == -1)
+    {
+      fd = gdb_open_cloexec (name, O_RDONLY | O_BINARY, 0);
+      if (fd == -1)
+	{
+	  bfd_set_error (bfd_error_system_call);
+	  return NULL;
+	}
+    }
+
+  search.filename = name;
+  if (fstat (fd, &st) < 0)
+    {
+      /* Weird situation here.  */
+      search.mtime = 0;
+    }
+  else
+    search.mtime = st.st_mtime;
+
+  /* Note that this must compute the same result as hash_bfd.  */
+  hash = htab_hash_string (name);
+  /* Note that we cannot use htab_find_slot_with_hash here, because
+     opening the BFD may fail; and this would violate hashtab
+     invariants.  */
+  abfd = htab_find_with_hash (gdb_bfd_cache, &search, hash);
+  if (abfd != NULL)
+    {
+      close (fd);
+      gdb_bfd_ref (abfd);
+      return abfd;
+    }
+
+  abfd = bfd_fopen (name, target, FOPEN_RB, fd);
+  if (abfd == NULL)
+    return NULL;
+
+  slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash, INSERT);
+  gdb_assert (!*slot);
+  *slot = abfd;
+
+  gdb_bfd_stash_filename (abfd);
+  gdb_bfd_ref (abfd);
+  return abfd;
+}
+
+/* A helper function that releases any section data attached to the
+   BFD.  */
+
+static void
+free_one_bfd_section (bfd *abfd, asection *sectp, void *ignore)
+{
+  struct gdb_bfd_section_data *sect = bfd_get_section_userdata (abfd, sectp);
+
+  if (sect != NULL && sect->data != NULL)
+    {
+#ifdef HAVE_MMAP
+      if (sect->map_addr != NULL)
+	{
+	  int res;
+
+	  res = munmap (sect->map_addr, sect->map_len);
+	  gdb_assert (res == 0);
+	}
+      else
+#endif
+	xfree (sect->data);
+    }
+}
+
+/* Close ABFD, and warn if that fails.  */
+
+static int
+gdb_bfd_close_or_warn (struct bfd *abfd)
+{
+  int ret;
+  char *name = bfd_get_filename (abfd);
+
+  bfd_map_over_sections (abfd, free_one_bfd_section, NULL);
+
+  ret = bfd_close (abfd);
+
+  if (!ret)
+    warning (_("cannot close \"%s\": %s"),
+	     name, bfd_errmsg (bfd_get_error ()));
+
+  return ret;
+}
+
+/* See gdb_bfd.h.  */
+
+void
+gdb_bfd_ref (struct bfd *abfd)
+{
+  struct gdb_bfd_data *gdata;
+  void **slot;
+
+  if (abfd == NULL)
+    return;
+
+  gdata = bfd_usrdata (abfd);
+
+  if (gdata != NULL)
+    {
+      gdata->refc += 1;
+      return;
+    }
+
+  /* Ask BFD to decompress sections in bfd_get_full_section_contents.  */
+  abfd->flags |= BFD_DECOMPRESS;
+
+  gdata = bfd_zalloc (abfd, sizeof (struct gdb_bfd_data));
+  gdata->refc = 1;
+  gdata->mtime = bfd_get_mtime (abfd);
+  gdata->archive_bfd = NULL;
+  bfd_usrdata (abfd) = gdata;
+
+  bfd_alloc_data (abfd);
+
+  /* This is the first we've seen it, so add it to the hash table.  */
+  slot = htab_find_slot (all_bfds, abfd, INSERT);
+  gdb_assert (slot && !*slot);
+  *slot = abfd;
+}
+
+/* See gdb_bfd.h.  */
+
+void
+gdb_bfd_unref (struct bfd *abfd)
+{
+  struct gdb_bfd_data *gdata;
+  struct gdb_bfd_cache_search search;
+  bfd *archive_bfd;
+
+  if (abfd == NULL)
+    return;
+
+  gdata = bfd_usrdata (abfd);
+  gdb_assert (gdata->refc >= 1);
+
+  gdata->refc -= 1;
+  if (gdata->refc > 0)
+    return;
+
+  archive_bfd = gdata->archive_bfd;
+  search.filename = bfd_get_filename (abfd);
+
+  if (gdb_bfd_cache && search.filename)
+    {
+      hashval_t hash = htab_hash_string (search.filename);
+      void **slot;
+
+      search.mtime = gdata->mtime;
+      slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash,
+				       NO_INSERT);
+
+      if (slot && *slot)
+	htab_clear_slot (gdb_bfd_cache, slot);
+    }
+
+  bfd_free_data (abfd);
+  bfd_usrdata (abfd) = NULL;  /* Paranoia.  */
+
+  htab_remove_elt (all_bfds, abfd);
+
+  gdb_bfd_close_or_warn (abfd);
+
+  gdb_bfd_unref (archive_bfd);
+}
+
+/* A helper function that returns the section data descriptor
+   associated with SECTION.  If no such descriptor exists, a new one
+   is allocated and cleared.  */
+
+static struct gdb_bfd_section_data *
+get_section_descriptor (asection *section)
+{
+  struct gdb_bfd_section_data *result;
+
+  result = bfd_get_section_userdata (section->owner, section);
+
+  if (result == NULL)
+    {
+      result = bfd_zalloc (section->owner, sizeof (*result));
+      bfd_set_section_userdata (section->owner, section, result);
+    }
+
+  return result;
+}
+
+/* See gdb_bfd.h.  */
+
+const gdb_byte *
+gdb_bfd_map_section (asection *sectp, bfd_size_type *size)
+{
+  bfd *abfd;
+  struct gdb_bfd_section_data *descriptor;
+  bfd_byte *data;
+
+  gdb_assert ((sectp->flags & SEC_RELOC) == 0);
+  gdb_assert (size != NULL);
+
+  abfd = sectp->owner;
+
+  descriptor = get_section_descriptor (sectp);
+
+  /* If the data was already read for this BFD, just reuse it.  */
+  if (descriptor->data != NULL)
+    goto done;
+
+#ifdef HAVE_MMAP
+  if (!bfd_is_section_compressed (abfd, sectp))
+    {
+      /* The page size, used when mmapping.  */
+      static int pagesize;
+
+      if (pagesize == 0)
+	pagesize = getpagesize ();
+
+      /* Only try to mmap sections which are large enough: we don't want
+	 to waste space due to fragmentation.  */
+
+      if (bfd_get_section_size (sectp) > 4 * pagesize)
+	{
+	  descriptor->size = bfd_get_section_size (sectp);
+	  descriptor->data = bfd_mmap (abfd, 0, descriptor->size, PROT_READ,
+				       MAP_PRIVATE, sectp->filepos,
+				       &descriptor->map_addr,
+				       &descriptor->map_len);
+
+	  if ((caddr_t)descriptor->data != MAP_FAILED)
+	    {
+#if HAVE_POSIX_MADVISE
+	      posix_madvise (descriptor->map_addr, descriptor->map_len,
+			     POSIX_MADV_WILLNEED);
+#endif
+	      goto done;
+	    }
+
+	  /* On failure, clear out the section data and try again.  */
+	  memset (descriptor, 0, sizeof (*descriptor));
+	}
+    }
+#endif /* HAVE_MMAP */
+
+  /* Handle compressed sections, or ordinary uncompressed sections in
+     the no-mmap case.  */
+
+  descriptor->size = bfd_get_section_size (sectp);
+  descriptor->data = NULL;
+
+  data = NULL;
+  if (!bfd_get_full_section_contents (abfd, sectp, &data))
+    error (_("Can't read data for section '%s' in file '%s'"),
+	   bfd_get_section_name (abfd, sectp),
+	   bfd_get_filename (abfd));
+  descriptor->data = data;
+
+ done:
+  gdb_assert (descriptor->data != NULL);
+  *size = descriptor->size;
+  return descriptor->data;
+}
+
+/* Return 32-bit CRC for ABFD.  If successful store it to *FILE_CRC_RETURN and
+   return 1.  Otherwise print a warning and return 0.  ABFD seek position is
+   not preserved.  */
+
+static int
+get_file_crc (bfd *abfd, unsigned long *file_crc_return)
+{
+  unsigned long file_crc = 0;
+
+  if (bfd_seek (abfd, 0, SEEK_SET) != 0)
+    {
+      warning (_("Problem reading \"%s\" for CRC: %s"),
+	       bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
+      return 0;
+    }
+
+  for (;;)
+    {
+      gdb_byte buffer[8 * 1024];
+      bfd_size_type count;
+
+      count = bfd_bread (buffer, sizeof (buffer), abfd);
+      if (count == (bfd_size_type) -1)
+	{
+	  warning (_("Problem reading \"%s\" for CRC: %s"),
+		   bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
+	  return 0;
+	}
+      if (count == 0)
+	break;
+      file_crc = bfd_calc_gnu_debuglink_crc32 (file_crc, buffer, count);
+    }
+
+  *file_crc_return = file_crc;
+  return 1;
+}
+
+/* See gdb_bfd.h.  */
+
+int
+gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out)
+{
+  struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
+
+  if (!gdata->crc_computed)
+    gdata->crc_computed = get_file_crc (abfd, &gdata->crc);
+
+  if (gdata->crc_computed)
+    *crc_out = gdata->crc;
+  return gdata->crc_computed;
+}
+
+
+
+/* See gdb_bfd.h.  */
+
+bfd *
+gdb_bfd_fopen (const char *filename, const char *target, const char *mode,
+	       int fd)
+{
+  bfd *result = bfd_fopen (filename, target, mode, fd);
+
+  if (result)
+    {
+      gdb_bfd_stash_filename (result);
+      gdb_bfd_ref (result);
+    }
+
+  return result;
+}
+
+/* See gdb_bfd.h.  */
+
+bfd *
+gdb_bfd_openr (const char *filename, const char *target)
+{
+  bfd *result = bfd_openr (filename, target);
+
+  if (result)
+    {
+      gdb_bfd_stash_filename (result);
+      gdb_bfd_ref (result);
+    }
+
+  return result;
+}
+
+/* See gdb_bfd.h.  */
+
+bfd *
+gdb_bfd_openw (const char *filename, const char *target)
+{
+  bfd *result = bfd_openw (filename, target);
+
+  if (result)
+    {
+      gdb_bfd_stash_filename (result);
+      gdb_bfd_ref (result);
+    }
+
+  return result;
+}
+
+/* See gdb_bfd.h.  */
+
+bfd *
+gdb_bfd_openr_iovec (const char *filename, const char *target,
+		     void *(*open_func) (struct bfd *nbfd,
+					 void *open_closure),
+		     void *open_closure,
+		     file_ptr (*pread_func) (struct bfd *nbfd,
+					     void *stream,
+					     void *buf,
+					     file_ptr nbytes,
+					     file_ptr offset),
+		     int (*close_func) (struct bfd *nbfd,
+					void *stream),
+		     int (*stat_func) (struct bfd *abfd,
+				       void *stream,
+				       struct stat *sb))
+{
+  bfd *result = bfd_openr_iovec (filename, target,
+				 open_func, open_closure,
+				 pread_func, close_func, stat_func);
+
+  if (result)
+    {
+      gdb_bfd_ref (result);
+      gdb_bfd_stash_filename (result);
+    }
+
+  return result;
+}
+
+/* See gdb_bfd.h.  */
+
+void
+gdb_bfd_mark_parent (bfd *child, bfd *parent)
+{
+  struct gdb_bfd_data *gdata;
+
+  gdb_bfd_ref (child);
+  /* No need to stash the filename here, because we also keep a
+     reference on the parent archive.  */
+
+  gdata = bfd_usrdata (child);
+  if (gdata->archive_bfd == NULL)
+    {
+      gdata->archive_bfd = parent;
+      gdb_bfd_ref (parent);
+    }
+  else
+    gdb_assert (gdata->archive_bfd == parent);
+}
+
+/* See gdb_bfd.h.  */
+
+bfd *
+gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous)
+{
+  bfd *result = bfd_openr_next_archived_file (archive, previous);
+
+  if (result)
+    gdb_bfd_mark_parent (result, archive);
+
+  return result;
+}
+
+/* See gdb_bfd.h.  */
+
+bfd *
+gdb_bfd_fdopenr (const char *filename, const char *target, int fd)
+{
+  bfd *result = bfd_fdopenr (filename, target, fd);
+
+  if (result)
+    {
+      gdb_bfd_ref (result);
+      gdb_bfd_stash_filename (result);
+    }
+
+  return result;
+}
+
+
+
+gdb_static_assert (ARRAY_SIZE (_bfd_std_section) == 4);
+
+/* See gdb_bfd.h.  */
+
+int
+gdb_bfd_section_index (bfd *abfd, asection *section)
+{
+  if (section == NULL)
+    return -1;
+  else if (section == bfd_com_section_ptr)
+    return bfd_count_sections (abfd) + 1;
+  else if (section == bfd_und_section_ptr)
+    return bfd_count_sections (abfd) + 2;
+  else if (section == bfd_abs_section_ptr)
+    return bfd_count_sections (abfd) + 3;
+  else if (section == bfd_ind_section_ptr)
+    return bfd_count_sections (abfd) + 4;
+  return section->index;
+}
+
+/* See gdb_bfd.h.  */
+
+int
+gdb_bfd_count_sections (bfd *abfd)
+{
+  return bfd_count_sections (abfd) + 4;
+}
+
+/* See gdb_bfd.h.  */
+
+int
+gdb_bfd_requires_relocations (bfd *abfd)
+{
+  struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
+
+  if (gdata->relocation_computed == 0)
+    {
+      asection *sect;
+
+      for (sect = abfd->sections; sect != NULL; sect = sect->next)
+	if ((sect->flags & SEC_RELOC) != 0)
+	  {
+	    gdata->needs_relocations = 1;
+	    break;
+	  }
+
+      gdata->relocation_computed = 1;
+    }
+
+  return gdata->needs_relocations;
+}
+
+
+
+/* A callback for htab_traverse that prints a single BFD.  */
+
+static int
+print_one_bfd (void **slot, void *data)
+{
+  bfd *abfd = *slot;
+  struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
+  struct ui_out *uiout = data;
+  struct cleanup *inner;
+
+  inner = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
+  ui_out_field_int (uiout, "refcount", gdata->refc);
+  ui_out_field_string (uiout, "addr", host_address_to_string (abfd));
+  ui_out_field_string (uiout, "filename", bfd_get_filename (abfd));
+  ui_out_text (uiout, "\n");
+  do_cleanups (inner);
+
+  return 1;
+}
+
+/* Implement the 'maint info bfd' command.  */
+
+static void
+maintenance_info_bfds (char *arg, int from_tty)
+{
+  struct cleanup *cleanup;
+  struct ui_out *uiout = current_uiout;
+
+  cleanup = make_cleanup_ui_out_table_begin_end (uiout, 3, -1, "bfds");
+  ui_out_table_header (uiout, 10, ui_left, "refcount", "Refcount");
+  ui_out_table_header (uiout, 18, ui_left, "addr", "Address");
+  ui_out_table_header (uiout, 40, ui_left, "filename", "Filename");
+
+  ui_out_table_body (uiout);
+  htab_traverse (all_bfds, print_one_bfd, uiout);
+
+  do_cleanups (cleanup);
+}
+
+/* -Wmissing-prototypes */
+extern initialize_file_ftype _initialize_gdb_bfd;
+
+void
+_initialize_gdb_bfd (void)
+{
+  all_bfds = htab_create_alloc (10, htab_hash_pointer, htab_eq_pointer,
+				NULL, xcalloc, xfree);
+
+  add_cmd ("bfds", class_maintenance, maintenance_info_bfds, _("\
+List the BFDs that are currently open."),
+	   &maintenanceinfolist);
+}