gdb/gdb_bfd.h

   1 /* Definitions for BFD wrappers used by GDB.
   2
   3    Copyright (C) 2011-2021 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 DECLARE_REGISTRY (bfd);
  30
  31 /* If supplied a path starting with this sequence, gdb_bfd_open will
  32    open BFDs using target fileio operations.  */
  33
  34 #define TARGET_SYSROOT_PREFIX "target:"
  35
  36 /* Returns nonzero if NAME starts with TARGET_SYSROOT_PREFIX, zero
  37    otherwise.  */
  38
  39 int is_target_filename (const char *name);
  40
  41 /* Returns nonzero if the filename associated with ABFD starts with
  42    TARGET_SYSROOT_PREFIX, zero otherwise.  */
  43
  44 int gdb_bfd_has_target_filename (struct bfd *abfd);
  45
  46 /* Increment the reference count of ABFD.  It is fine for ABFD to be
  47    NULL; in this case the function does nothing.  */
  48
  49 void gdb_bfd_ref (struct bfd *abfd);
  50
  51 /* Decrement the reference count of ABFD.  If this is the last
  52    reference, ABFD will be freed.  If ABFD is NULL, this function does
  53    nothing.  */
  54
  55 void gdb_bfd_unref (struct bfd *abfd);
  56
  57 /* A policy class for gdb::ref_ptr for BFD reference counting.  */
  58 struct gdb_bfd_ref_policy
  59 {
  60   static void incref (struct bfd *abfd)
  61   {
  62     gdb_bfd_ref (abfd);
  63   }
  64
  65   static void decref (struct bfd *abfd)
  66   {
  67     gdb_bfd_unref (abfd);
  68   }
  69 };
  70
  71 /* A gdb::ref_ptr that has been specialized for BFD objects.  */
  72 typedef gdb::ref_ptr<struct bfd, gdb_bfd_ref_policy> gdb_bfd_ref_ptr;
  73
  74 /* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
  75    If NAME starts with TARGET_SYSROOT_PREFIX then the BFD will be
  76    opened using target fileio operations if necessary.  Returns NULL
  77    on error.  On success, returns a new reference to the BFD.  BFDs
  78    returned by this call are shared among all callers opening the same
  79    file.  If FD is not -1, then after this call it is owned by BFD.
  80    If the BFD was not accessed using target fileio operations then the
  81    filename associated with the BFD and accessible with
  82    bfd_get_filename will not be exactly NAME but rather NAME with
  83    TARGET_SYSROOT_PREFIX stripped.  If WARN_IF_SLOW is true, print a
  84    warning message if the file is being accessed over a link that may
  85    be slow.  */
  86
  87 gdb_bfd_ref_ptr gdb_bfd_open (const char *name, const char *target,
  88                               int fd = -1, bool warn_if_slow = true);
  89
  90 /* Mark the CHILD BFD as being a member of PARENT.  Also, increment
  91    the reference count of CHILD.  Calling this function ensures that
  92    as along as CHILD remains alive, PARENT will as well.  Both CHILD
  93    and PARENT must be non-NULL.  This can be called more than once
  94    with the same arguments; but it is not allowed to call it for a
  95    single CHILD with different values for PARENT.  */
  96
  97 void gdb_bfd_mark_parent (bfd *child, bfd *parent);
  98
  99 /* Mark INCLUDEE as being included by INCLUDER.
 100    This is used to associate the life time of INCLUDEE with INCLUDER.
 101    For example, with Fission, one file can refer to debug info in another
 102    file, and internal tables we build for the main file (INCLUDER) may refer
 103    to data contained in INCLUDEE.  Therefore we want to keep INCLUDEE around
 104    at least as long as INCLUDER exists.
 105
 106    Note that this is different than gdb_bfd_mark_parent because in our case
 107    lifetime tracking is based on the "parent" whereas in gdb_bfd_mark_parent
 108    lifetime tracking is based on the "child".  Plus in our case INCLUDEE could
 109    have multiple different "parents".  */
 110
 111 void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
 112
 113 /* Try to read or map the contents of the section SECT.  If successful, the
 114    section data is returned and *SIZE is set to the size of the section data;
 115    this may not be the same as the size according to bfd_section_size if the
 116    section was compressed.  The returned section data is associated with the BFD
 117    and will be destroyed when the BFD is destroyed.  There is no other way to
 118    free it; for temporary uses of section data, see bfd_malloc_and_get_section.
 119    SECT may not have relocations.  If there is an error reading the section,
 120    this issues a warning, sets *SIZE to 0, and returns NULL.  */
 121
 122 const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
 123
 124 /* Compute the CRC for ABFD.  The CRC is used to find and verify
 125    separate debug files.  When successful, this fills in *CRC_OUT and
 126    returns 1.  Otherwise, this issues a warning and returns 0.  */
 127
 128 int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
 129
 130 \f
 131
 132 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
 133    count.  */
 134
 135 gdb_bfd_ref_ptr gdb_bfd_fopen (const char *, const char *, const char *, int);
 136
 137 /* A wrapper for bfd_openr that initializes the gdb-specific reference
 138    count.  */
 139
 140 gdb_bfd_ref_ptr gdb_bfd_openr (const char *, const char *);
 141
 142 /* A wrapper for bfd_openw that initializes the gdb-specific reference
 143    count.  */
 144
 145 gdb_bfd_ref_ptr gdb_bfd_openw (const char *, const char *);
 146
 147 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
 148    reference count.  */
 149
 150 gdb_bfd_ref_ptr gdb_bfd_openr_iovec (const char *filename, const char *target,
 151                                      void *(*open_func) (struct bfd *nbfd,
 152                                                          void *open_closure),
 153                                      void *open_closure,
 154                                      file_ptr (*pread_func) (struct bfd *nbfd,
 155                                                              void *stream,
 156                                                              void *buf,
 157                                                              file_ptr nbytes,
 158                                                              file_ptr offset),
 159                                      int (*close_func) (struct bfd *nbfd,
 160                                                         void *stream),
 161                                      int (*stat_func) (struct bfd *abfd,
 162                                                        void *stream,
 163                                                        struct stat *sb));
 164
 165 /* A wrapper for bfd_openr_next_archived_file that initializes the
 166    gdb-specific reference count.  */
 167
 168 gdb_bfd_ref_ptr gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 169
 170
 171 \f
 172
 173 /* Return the index of the BFD section SECTION.  Ordinarily this is
 174    just the section's index, but for some special sections, like
 175    bfd_com_section_ptr, it will be a synthesized value.  */
 176
 177 int gdb_bfd_section_index (bfd *abfd, asection *section);
 178
 179
 180 /* Like bfd_count_sections, but include any possible global sections,
 181    like bfd_com_section_ptr.  */
 182
 183 int gdb_bfd_count_sections (bfd *abfd);
 184
 185 /* Return true if any section requires relocations, false
 186    otherwise.  */
 187
 188 int gdb_bfd_requires_relocations (bfd *abfd);
 189
 190 /* Alternative to bfd_get_full_section_contents that returns the section
 191    contents in *CONTENTS, instead of an allocated buffer.
 192
 193    Return true on success, false otherwise.  */
 194
 195 bool gdb_bfd_get_full_section_contents (bfd *abfd, asection *section,
 196                                         gdb::byte_vector *contents);
 197
 198 /* Create and initialize a BFD handle from a target in-memory range.  */
 199
 200 gdb_bfd_ref_ptr gdb_bfd_open_from_target_memory (CORE_ADDR addr, ULONGEST size,
 201                                                  const char *target,
 202                                                  const char *filename = nullptr);
 203
 204 /* Range adapter for a BFD's sections.
 205
 206    To be used as:
 207
 208      for (asection *sect : gdb_bfd_all_sections (bfd))
 209        ... use SECT ...
 210  */
 211
 212 using gdb_bfd_section_range = next_range<asection>;
 213
 214 static inline gdb_bfd_section_range
 215 gdb_bfd_sections (bfd *abfd)
 216 {
 217   return gdb_bfd_section_range (abfd->sections);
 218 }
 219
 220 static inline gdb_bfd_section_range
 221 gdb_bfd_sections (const gdb_bfd_ref_ptr &abfd)
 222 {
 223   return gdb_bfd_section_range (abfd->sections);
 224 };
 225
 226 #endif /* GDB_BFD_H */