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