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.  */
  82
  83 gdb_bfd_ref_ptr gdb_bfd_open (const char *name, const char *target,
  84                               int fd = -1);
  85
  86 /* Mark the CHILD BFD as being a member of PARENT.  Also, increment
  87    the reference count of CHILD.  Calling this function ensures that
  88    as along as CHILD remains alive, PARENT will as well.  Both CHILD
  89    and PARENT must be non-NULL.  This can be called more than once
  90    with the same arguments; but it is not allowed to call it for a
  91    single CHILD with different values for PARENT.  */
  92
  93 void gdb_bfd_mark_parent (bfd *child, bfd *parent);
  94
  95 /* Mark INCLUDEE as being included by INCLUDER.
  96    This is used to associate the life time of INCLUDEE with INCLUDER.
  97    For example, with Fission, one file can refer to debug info in another
  98    file, and internal tables we build for the main file (INCLUDER) may refer
  99    to data contained in INCLUDEE.  Therefore we want to keep INCLUDEE around
 100    at least as long as INCLUDER exists.
 101
 102    Note that this is different than gdb_bfd_mark_parent because in our case
 103    lifetime tracking is based on the "parent" whereas in gdb_bfd_mark_parent
 104    lifetime tracking is based on the "child".  Plus in our case INCLUDEE could
 105    have multiple different "parents".  */
 106
 107 void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
 108
 109 /* Try to read or map the contents of the section SECT.  If successful, the
 110    section data is returned and *SIZE is set to the size of the section data;
 111    this may not be the same as the size according to bfd_section_size if the
 112    section was compressed.  The returned section data is associated with the BFD
 113    and will be destroyed when the BFD is destroyed.  There is no other way to
 114    free it; for temporary uses of section data, see bfd_malloc_and_get_section.
 115    SECT may not have relocations.  If there is an error reading the section,
 116    this issues a warning, sets *SIZE to 0, and returns NULL.  */
 117
 118 const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
 119
 120 /* Compute the CRC for ABFD.  The CRC is used to find and verify
 121    separate debug files.  When successful, this fills in *CRC_OUT and
 122    returns 1.  Otherwise, this issues a warning and returns 0.  */
 123
 124 int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
 125
 126 \f
 127
 128 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
 129    count.  */
 130
 131 gdb_bfd_ref_ptr gdb_bfd_fopen (const char *, const char *, const char *, int);
 132
 133 /* A wrapper for bfd_openr that initializes the gdb-specific reference
 134    count.  */
 135
 136 gdb_bfd_ref_ptr gdb_bfd_openr (const char *, const char *);
 137
 138 /* A wrapper for bfd_openw that initializes the gdb-specific reference
 139    count.  */
 140
 141 gdb_bfd_ref_ptr gdb_bfd_openw (const char *, const char *);
 142
 143 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
 144    reference count.  */
 145
 146 gdb_bfd_ref_ptr gdb_bfd_openr_iovec (const char *filename, const char *target,
 147                                      void *(*open_func) (struct bfd *nbfd,
 148                                                          void *open_closure),
 149                                      void *open_closure,
 150                                      file_ptr (*pread_func) (struct bfd *nbfd,
 151                                                              void *stream,
 152                                                              void *buf,
 153                                                              file_ptr nbytes,
 154                                                              file_ptr offset),
 155                                      int (*close_func) (struct bfd *nbfd,
 156                                                         void *stream),
 157                                      int (*stat_func) (struct bfd *abfd,
 158                                                        void *stream,
 159                                                        struct stat *sb));
 160
 161 /* A wrapper for bfd_openr_next_archived_file that initializes the
 162    gdb-specific reference count.  */
 163
 164 gdb_bfd_ref_ptr gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 165
 166
 167 \f
 168
 169 /* Return the index of the BFD section SECTION.  Ordinarily this is
 170    just the section's index, but for some special sections, like
 171    bfd_com_section_ptr, it will be a synthesized value.  */
 172
 173 int gdb_bfd_section_index (bfd *abfd, asection *section);
 174
 175
 176 /* Like bfd_count_sections, but include any possible global sections,
 177    like bfd_com_section_ptr.  */
 178
 179 int gdb_bfd_count_sections (bfd *abfd);
 180
 181 /* Return true if any section requires relocations, false
 182    otherwise.  */
 183
 184 int gdb_bfd_requires_relocations (bfd *abfd);
 185
 186 /* Alternative to bfd_get_full_section_contents that returns the section
 187    contents in *CONTENTS, instead of an allocated buffer.
 188
 189    Return true on success, false otherwise.  */
 190
 191 bool gdb_bfd_get_full_section_contents (bfd *abfd, asection *section,
 192                                         gdb::byte_vector *contents);
 193
 194 #endif /* GDB_BFD_H */