gdb/gdb_bfd.h

   1 /* Definitions for BFD wrappers used by GDB.
   2
   3    Copyright (C) 2011-2023 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 "gdbsupport/byte-vector.h"
  25 #include "gdbsupport/gdb_ref_ptr.h"
  26 #include "gdbsupport/iterator-range.h"
  27 #include "gdbsupport/next-iterator.h"
  28
  29 /* A registry adaptor for BFD.  This arranges to store the registry in
  30    gdb's per-BFD data, which is stored as the bfd_usrdata.  */
  31 template<>
  32 struct registry_accessor<bfd>
  33 {
  34   static registry<bfd> *get (bfd *abfd);
  35 };
  36
  37 /* If supplied a path starting with this sequence, gdb_bfd_open will
  38    open BFDs using target fileio operations.  */
  39
  40 #define TARGET_SYSROOT_PREFIX "target:"
  41
  42 /* Returns nonzero if NAME starts with TARGET_SYSROOT_PREFIX, zero
  43    otherwise.  */
  44
  45 int is_target_filename (const char *name);
  46
  47 /* Returns nonzero if the filename associated with ABFD starts with
  48    TARGET_SYSROOT_PREFIX, zero otherwise.  */
  49
  50 int gdb_bfd_has_target_filename (struct bfd *abfd);
  51
  52 /* Increment the reference count of ABFD.  It is fine for ABFD to be
  53    NULL; in this case the function does nothing.  */
  54
  55 void gdb_bfd_ref (struct bfd *abfd);
  56
  57 /* Decrement the reference count of ABFD.  If this is the last
  58    reference, ABFD will be freed.  If ABFD is NULL, this function does
  59    nothing.  */
  60
  61 void gdb_bfd_unref (struct bfd *abfd);
  62
  63 /* A policy class for gdb::ref_ptr for BFD reference counting.  */
  64 struct gdb_bfd_ref_policy
  65 {
  66   static void incref (struct bfd *abfd)
  67   {
  68     gdb_bfd_ref (abfd);
  69   }
  70
  71   static void decref (struct bfd *abfd)
  72   {
  73     gdb_bfd_unref (abfd);
  74   }
  75 };
  76
  77 /* A gdb::ref_ptr that has been specialized for BFD objects.  */
  78 typedef gdb::ref_ptr<struct bfd, gdb_bfd_ref_policy> gdb_bfd_ref_ptr;
  79
  80 /* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
  81    If NAME starts with TARGET_SYSROOT_PREFIX then the BFD will be
  82    opened using target fileio operations if necessary.  Returns NULL
  83    on error.  On success, returns a new reference to the BFD.  BFDs
  84    returned by this call are shared among all callers opening the same
  85    file.  If FD is not -1, then after this call it is owned by BFD.
  86    If the BFD was not accessed using target fileio operations then the
  87    filename associated with the BFD and accessible with
  88    bfd_get_filename will not be exactly NAME but rather NAME with
  89    TARGET_SYSROOT_PREFIX stripped.  If WARN_IF_SLOW is true, print a
  90    warning message if the file is being accessed over a link that may
  91    be slow.  */
  92
  93 gdb_bfd_ref_ptr gdb_bfd_open (const char *name, const char *target,
  94                               int fd = -1, bool warn_if_slow = true);
  95
  96 /* Mark the CHILD BFD as being a member of PARENT.  Also, increment
  97    the reference count of CHILD.  Calling this function ensures that
  98    as along as CHILD remains alive, PARENT will as well.  Both CHILD
  99    and PARENT must be non-NULL.  This can be called more than once
 100    with the same arguments; but it is not allowed to call it for a
 101    single CHILD with different values for PARENT.  */
 102
 103 void gdb_bfd_mark_parent (bfd *child, bfd *parent);
 104
 105 /* Mark INCLUDEE as being included by INCLUDER.
 106    This is used to associate the life time of INCLUDEE with INCLUDER.
 107    For example, with Fission, one file can refer to debug info in another
 108    file, and internal tables we build for the main file (INCLUDER) may refer
 109    to data contained in INCLUDEE.  Therefore we want to keep INCLUDEE around
 110    at least as long as INCLUDER exists.
 111
 112    Note that this is different than gdb_bfd_mark_parent because in our case
 113    lifetime tracking is based on the "parent" whereas in gdb_bfd_mark_parent
 114    lifetime tracking is based on the "child".  Plus in our case INCLUDEE could
 115    have multiple different "parents".  */
 116
 117 void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
 118
 119 /* Try to read or map the contents of the section SECT.  If successful, the
 120    section data is returned and *SIZE is set to the size of the section data;
 121    this may not be the same as the size according to bfd_section_size if the
 122    section was compressed.  The returned section data is associated with the BFD
 123    and will be destroyed when the BFD is destroyed.  There is no other way to
 124    free it; for temporary uses of section data, see bfd_malloc_and_get_section.
 125    SECT may not have relocations.  If there is an error reading the section,
 126    this issues a warning, sets *SIZE to 0, and returns NULL.  */
 127
 128 const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
 129
 130 /* Compute the CRC for ABFD.  The CRC is used to find and verify
 131    separate debug files.  When successful, this fills in *CRC_OUT and
 132    returns 1.  Otherwise, this issues a warning and returns 0.  */
 133
 134 int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
 135
 136 \f
 137
 138 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
 139    count.  */
 140
 141 gdb_bfd_ref_ptr gdb_bfd_fopen (const char *, const char *, const char *, int);
 142
 143 /* A wrapper for bfd_openr that initializes the gdb-specific reference
 144    count.  */
 145
 146 gdb_bfd_ref_ptr gdb_bfd_openr (const char *, const char *);
 147
 148 /* A wrapper for bfd_openw that initializes the gdb-specific reference
 149    count.  */
 150
 151 gdb_bfd_ref_ptr gdb_bfd_openw (const char *, const char *);
 152
 153 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
 154    reference count.  */
 155
 156 gdb_bfd_ref_ptr gdb_bfd_openr_iovec (const char *filename, const char *target,
 157                                      void *(*open_func) (struct bfd *nbfd,
 158                                                          void *open_closure),
 159                                      void *open_closure,
 160                                      file_ptr (*pread_func) (struct bfd *nbfd,
 161                                                              void *stream,
 162                                                              void *buf,
 163                                                              file_ptr nbytes,
 164                                                              file_ptr offset),
 165                                      int (*close_func) (struct bfd *nbfd,
 166                                                         void *stream),
 167                                      int (*stat_func) (struct bfd *abfd,
 168                                                        void *stream,
 169                                                        struct stat *sb));
 170
 171 /* A wrapper for bfd_openr_next_archived_file that initializes the
 172    gdb-specific reference count.  */
 173
 174 gdb_bfd_ref_ptr gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 175
 176
 177 \f
 178
 179 /* Return the index of the BFD section SECTION.  Ordinarily this is
 180    just the section's index, but for some special sections, like
 181    bfd_com_section_ptr, it will be a synthesized value.  */
 182
 183 int gdb_bfd_section_index (bfd *abfd, asection *section);
 184
 185
 186 /* Like bfd_count_sections, but include any possible global sections,
 187    like bfd_com_section_ptr.  */
 188
 189 int gdb_bfd_count_sections (bfd *abfd);
 190
 191 /* Return true if any section requires relocations, false
 192    otherwise.  */
 193
 194 int gdb_bfd_requires_relocations (bfd *abfd);
 195
 196 /* Alternative to bfd_get_full_section_contents that returns the section
 197    contents in *CONTENTS, instead of an allocated buffer.
 198
 199    Return true on success, false otherwise.  */
 200
 201 bool gdb_bfd_get_full_section_contents (bfd *abfd, asection *section,
 202                                         gdb::byte_vector *contents);
 203
 204 /* Create and initialize a BFD handle from a target in-memory range.  The
 205    BFD starts at ADDR and is SIZE bytes long.  TARGET is the BFD target
 206    name as used in bfd_find_target.  */
 207
 208 gdb_bfd_ref_ptr gdb_bfd_open_from_target_memory (CORE_ADDR addr, ULONGEST size,
 209                                                  const char *target);
 210
 211 /* Range adapter for a BFD's sections.
 212
 213    To be used as:
 214
 215      for (asection *sect : gdb_bfd_all_sections (bfd))
 216        ... use SECT ...
 217  */
 218
 219 using gdb_bfd_section_range = next_range<asection>;
 220
 221 static inline gdb_bfd_section_range
 222 gdb_bfd_sections (bfd *abfd)
 223 {
 224   return gdb_bfd_section_range (abfd->sections);
 225 }
 226
 227 static inline gdb_bfd_section_range
 228 gdb_bfd_sections (const gdb_bfd_ref_ptr &abfd)
 229 {
 230   return gdb_bfd_section_range (abfd->sections);
 231 };
 232
 233 /* A wrapper for bfd_errmsg to produce a more helpful error message
 234    in the case of bfd_error_file_ambiguously recognized.
 235    MATCHING, if non-NULL, is the corresponding argument to
 236    bfd_check_format_matches, and will be freed.  */
 237
 238 extern std::string gdb_bfd_errmsg (bfd_error_type error_tag, char **matching);
 239
 240 #endif /* GDB_BFD_H */