gdb/gdb_bfd.h

   1 /* Definitions for BFD wrappers used by GDB.
   2
   3    Copyright (C) 2011-2020 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
  27 DECLARE_REGISTRY (bfd);
  28
  29 /* If supplied a path starting with this sequence, gdb_bfd_open will
  30    open BFDs using target fileio operations.  */
  31
  32 #define TARGET_SYSROOT_PREFIX "target:"
  33
  34 /* Returns nonzero if NAME starts with TARGET_SYSROOT_PREFIX, zero
  35    otherwise.  */
  36
  37 int is_target_filename (const char *name);
  38
  39 /* Returns nonzero if the filename associated with ABFD starts with
  40    TARGET_SYSROOT_PREFIX, zero otherwise.  */
  41
  42 int gdb_bfd_has_target_filename (struct bfd *abfd);
  43
  44 /* Increment the reference count of ABFD.  It is fine for ABFD to be
  45    NULL; in this case the function does nothing.  */
  46
  47 void gdb_bfd_ref (struct bfd *abfd);
  48
  49 /* Decrement the reference count of ABFD.  If this is the last
  50    reference, ABFD will be freed.  If ABFD is NULL, this function does
  51    nothing.  */
  52
  53 void gdb_bfd_unref (struct bfd *abfd);
  54
  55 /* A policy class for gdb::ref_ptr for BFD reference counting.  */
  56 struct gdb_bfd_ref_policy
  57 {
  58   static void incref (struct bfd *abfd)
  59   {
  60     gdb_bfd_ref (abfd);
  61   }
  62
  63   static void decref (struct bfd *abfd)
  64   {
  65     gdb_bfd_unref (abfd);
  66   }
  67 };
  68
  69 /* A gdb::ref_ptr that has been specialized for BFD objects.  */
  70 typedef gdb::ref_ptr<struct bfd, gdb_bfd_ref_policy> gdb_bfd_ref_ptr;
  71
  72 /* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
  73    If NAME starts with TARGET_SYSROOT_PREFIX then the BFD will be
  74    opened using target fileio operations if necessary.  Returns NULL
  75    on error.  On success, returns a new reference to the BFD.  BFDs
  76    returned by this call are shared among all callers opening the same
  77    file.  If FD is not -1, then after this call it is owned by BFD.
  78    If the BFD was not accessed using target fileio operations then the
  79    filename associated with the BFD and accessible with
  80    bfd_get_filename will not be exactly NAME but rather NAME with
  81    TARGET_SYSROOT_PREFIX stripped.  If WARN_IF_SLOW is true, print a
  82    warning message if the file is being accessed over a link that may
  83    be slow.  */
  84
  85 gdb_bfd_ref_ptr gdb_bfd_open (const char *name, const char *target,
  86                               int fd = -1, bool warn_if_slow = true);
  87
  88 /* Mark the CHILD BFD as being a member of PARENT.  Also, increment
  89    the reference count of CHILD.  Calling this function ensures that
  90    as along as CHILD remains alive, PARENT will as well.  Both CHILD
  91    and PARENT must be non-NULL.  This can be called more than once
  92    with the same arguments; but it is not allowed to call it for a
  93    single CHILD with different values for PARENT.  */
  94
  95 void gdb_bfd_mark_parent (bfd *child, bfd *parent);
  96
  97 /* Mark INCLUDEE as being included by INCLUDER.
  98    This is used to associate the life time of INCLUDEE with INCLUDER.
  99    For example, with Fission, one file can refer to debug info in another
 100    file, and internal tables we build for the main file (INCLUDER) may refer
 101    to data contained in INCLUDEE.  Therefore we want to keep INCLUDEE around
 102    at least as long as INCLUDER exists.
 103
 104    Note that this is different than gdb_bfd_mark_parent because in our case
 105    lifetime tracking is based on the "parent" whereas in gdb_bfd_mark_parent
 106    lifetime tracking is based on the "child".  Plus in our case INCLUDEE could
 107    have multiple different "parents".  */
 108
 109 void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
 110
 111 /* Try to read or map the contents of the section SECT.  If successful, the
 112    section data is returned and *SIZE is set to the size of the section data;
 113    this may not be the same as the size according to bfd_section_size if the
 114    section was compressed.  The returned section data is associated with the BFD
 115    and will be destroyed when the BFD is destroyed.  There is no other way to
 116    free it; for temporary uses of section data, see bfd_malloc_and_get_section.
 117    SECT may not have relocations.  If there is an error reading the section,
 118    this issues a warning, sets *SIZE to 0, and returns NULL.  */
 119
 120 const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
 121
 122 /* Compute the CRC for ABFD.  The CRC is used to find and verify
 123    separate debug files.  When successful, this fills in *CRC_OUT and
 124    returns 1.  Otherwise, this issues a warning and returns 0.  */
 125
 126 int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
 127
 128 \f
 129
 130 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
 131    count.  */
 132
 133 gdb_bfd_ref_ptr gdb_bfd_fopen (const char *, const char *, const char *, int);
 134
 135 /* A wrapper for bfd_openr that initializes the gdb-specific reference
 136    count.  */
 137
 138 gdb_bfd_ref_ptr gdb_bfd_openr (const char *, const char *);
 139
 140 /* A wrapper for bfd_openw that initializes the gdb-specific reference
 141    count.  */
 142
 143 gdb_bfd_ref_ptr gdb_bfd_openw (const char *, const char *);
 144
 145 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
 146    reference count.  */
 147
 148 gdb_bfd_ref_ptr gdb_bfd_openr_iovec (const char *filename, const char *target,
 149                                      void *(*open_func) (struct bfd *nbfd,
 150                                                          void *open_closure),
 151                                      void *open_closure,
 152                                      file_ptr (*pread_func) (struct bfd *nbfd,
 153                                                              void *stream,
 154                                                              void *buf,
 155                                                              file_ptr nbytes,
 156                                                              file_ptr offset),
 157                                      int (*close_func) (struct bfd *nbfd,
 158                                                         void *stream),
 159                                      int (*stat_func) (struct bfd *abfd,
 160                                                        void *stream,
 161                                                        struct stat *sb));
 162
 163 /* A wrapper for bfd_openr_next_archived_file that initializes the
 164    gdb-specific reference count.  */
 165
 166 gdb_bfd_ref_ptr gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 167
 168
 169 \f
 170
 171 /* Return the index of the BFD section SECTION.  Ordinarily this is
 172    just the section's index, but for some special sections, like
 173    bfd_com_section_ptr, it will be a synthesized value.  */
 174
 175 int gdb_bfd_section_index (bfd *abfd, asection *section);
 176
 177
 178 /* Like bfd_count_sections, but include any possible global sections,
 179    like bfd_com_section_ptr.  */
 180
 181 int gdb_bfd_count_sections (bfd *abfd);
 182
 183 /* Return true if any section requires relocations, false
 184    otherwise.  */
 185
 186 int gdb_bfd_requires_relocations (bfd *abfd);
 187
 188 /* Alternative to bfd_get_full_section_contents that returns the section
 189    contents in *CONTENTS, instead of an allocated buffer.
 190
 191    Return true on success, false otherwise.  */
 192
 193 bool gdb_bfd_get_full_section_contents (bfd *abfd, asection *section,
 194                                         gdb::byte_vector *contents);
 195
 196 #endif /* GDB_BFD_H */