gdb/gdb_bfd.h

   1 /* Definitions for BFD wrappers used by GDB.
   2
   3    Copyright (C) 2011-2018 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GDB_BFD_H
  21 #define GDB_BFD_H
  22
  23 #include "registry.h"
  24 #include "common/gdb_ref_ptr.h"
  25
  26 DECLARE_REGISTRY (bfd);
  27
  28 /* If supplied a path starting with this sequence, gdb_bfd_open will
  29    open BFDs using target fileio operations.  */
  30
  31 #define TARGET_SYSROOT_PREFIX "target:"
  32
  33 /* Returns nonzero if NAME starts with TARGET_SYSROOT_PREFIX, zero
  34    otherwise.  */
  35
  36 int is_target_filename (const char *name);
  37
  38 /* Returns nonzero if the filename associated with ABFD starts with
  39    TARGET_SYSROOT_PREFIX, zero otherwise.  */
  40
  41 int gdb_bfd_has_target_filename (struct bfd *abfd);
  42
  43 /* Increment the reference count of ABFD.  It is fine for ABFD to be
  44    NULL; in this case the function does nothing.  */
  45
  46 void gdb_bfd_ref (struct bfd *abfd);
  47
  48 /* Decrement the reference count of ABFD.  If this is the last
  49    reference, ABFD will be freed.  If ABFD is NULL, this function does
  50    nothing.  */
  51
  52 void gdb_bfd_unref (struct bfd *abfd);
  53
  54 /* A policy class for gdb::ref_ptr for BFD reference counting.  */
  55 struct gdb_bfd_ref_policy
  56 {
  57   static void incref (struct bfd *abfd)
  58   {
  59     gdb_bfd_ref (abfd);
  60   }
  61
  62   static void decref (struct bfd *abfd)
  63   {
  64     gdb_bfd_unref (abfd);
  65   }
  66 };
  67
  68 /* A gdb::ref_ptr that has been specialized for BFD objects.  */
  69 typedef gdb::ref_ptr<struct bfd, gdb_bfd_ref_policy> gdb_bfd_ref_ptr;
  70
  71 /* A helper function that calls gdb_bfd_ref and returns a
  72    gdb_bfd_ref_ptr.  */
  73
  74 static inline gdb_bfd_ref_ptr
  75 new_bfd_ref (struct bfd *abfd)
  76 {
  77   gdb_bfd_ref (abfd);
  78   return gdb_bfd_ref_ptr (abfd);
  79 }
  80
  81 /* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
  82    If NAME starts with TARGET_SYSROOT_PREFIX then the BFD will be
  83    opened using target fileio operations if necessary.  Returns NULL
  84    on error.  On success, returns a new reference to the BFD, which
  85    must be freed with gdb_bfd_unref.  BFDs returned by this call are
  86    shared among all callers opening the same file.  If FD is not -1,
  87    then after this call it is owned by BFD.  If the BFD was not
  88    accessed using target fileio operations then the filename
  89    associated with the BFD and accessible with bfd_get_filename will
  90    not be exactly NAME but rather NAME with TARGET_SYSROOT_PREFIX
  91    stripped.  */
  92
  93 gdb_bfd_ref_ptr gdb_bfd_open (const char *name, const char *target, int fd);
  94
  95 /* Mark the CHILD BFD as being a member of PARENT.  Also, increment
  96    the reference count of CHILD.  Calling this function ensures that
  97    as along as CHILD remains alive, PARENT will as well.  Both CHILD
  98    and PARENT must be non-NULL.  This can be called more than once
  99    with the same arguments; but it is not allowed to call it for a
 100    single CHILD with different values for PARENT.  */
 101
 102 void gdb_bfd_mark_parent (bfd *child, bfd *parent);
 103
 104 /* Mark INCLUDEE as being included by INCLUDER.
 105    This is used to associate the life time of INCLUDEE with INCLUDER.
 106    For example, with Fission, one file can refer to debug info in another
 107    file, and internal tables we build for the main file (INCLUDER) may refer
 108    to data contained in INCLUDEE.  Therefore we want to keep INCLUDEE around
 109    at least as long as INCLUDER exists.
 110
 111    Note that this is different than gdb_bfd_mark_parent because in our case
 112    lifetime tracking is based on the "parent" whereas in gdb_bfd_mark_parent
 113    lifetime tracking is based on the "child".  Plus in our case INCLUDEE could
 114    have multiple different "parents".  */
 115
 116 void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
 117
 118 /* Try to read or map the contents of the section SECT.  If successful, the
 119    section data is returned and *SIZE is set to the size of the section data;
 120    this may not be the same as the size according to bfd_get_section_size if the
 121    section was compressed.  The returned section data is associated with the BFD
 122    and will be destroyed when the BFD is destroyed.  There is no other way to
 123    free it; for temporary uses of section data, see bfd_malloc_and_get_section.
 124    SECT may not have relocations.  If there is an error reading the section,
 125    this issues a warning, sets *SIZE to 0, and returns NULL.  */
 126
 127 const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
 128
 129 /* Compute the CRC for ABFD.  The CRC is used to find and verify
 130    separate debug files.  When successful, this fills in *CRC_OUT and
 131    returns 1.  Otherwise, this issues a warning and returns 0.  */
 132
 133 int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
 134
 135 \f
 136
 137 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
 138    count.  */
 139
 140 gdb_bfd_ref_ptr gdb_bfd_fopen (const char *, const char *, const char *, int);
 141
 142 /* A wrapper for bfd_openr that initializes the gdb-specific reference
 143    count.  */
 144
 145 gdb_bfd_ref_ptr gdb_bfd_openr (const char *, const char *);
 146
 147 /* A wrapper for bfd_openw that initializes the gdb-specific reference
 148    count.  */
 149
 150 gdb_bfd_ref_ptr gdb_bfd_openw (const char *, const char *);
 151
 152 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
 153    reference count.  */
 154
 155 gdb_bfd_ref_ptr gdb_bfd_openr_iovec (const char *filename, const char *target,
 156                                      void *(*open_func) (struct bfd *nbfd,
 157                                                          void *open_closure),
 158                                      void *open_closure,
 159                                      file_ptr (*pread_func) (struct bfd *nbfd,
 160                                                              void *stream,
 161                                                              void *buf,
 162                                                              file_ptr nbytes,
 163                                                              file_ptr offset),
 164                                      int (*close_func) (struct bfd *nbfd,
 165                                                         void *stream),
 166                                      int (*stat_func) (struct bfd *abfd,
 167                                                        void *stream,
 168                                                        struct stat *sb));
 169
 170 /* A wrapper for bfd_openr_next_archived_file that initializes the
 171    gdb-specific reference count.  */
 172
 173 gdb_bfd_ref_ptr gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 174
 175 /* A wrapper for bfd_fdopenr that initializes the gdb-specific
 176    reference count.  */
 177
 178 gdb_bfd_ref_ptr gdb_bfd_fdopenr (const char *filename, const char *target,
 179                                  int fd);
 180
 181 \f
 182
 183 /* Return the index of the BFD section SECTION.  Ordinarily this is
 184    just the section's index, but for some special sections, like
 185    bfd_com_section_ptr, it will be a synthesized value.  */
 186
 187 int gdb_bfd_section_index (bfd *abfd, asection *section);
 188
 189
 190 /* Like bfd_count_sections, but include any possible global sections,
 191    like bfd_com_section_ptr.  */
 192
 193 int gdb_bfd_count_sections (bfd *abfd);
 194
 195 /* Return true if any section requires relocations, false
 196    otherwise.  */
 197
 198 int gdb_bfd_requires_relocations (bfd *abfd);
 199
 200 #endif /* GDB_BFD_H */