gdb/gdb_bfd.h

   1 /* Definitions for BFD wrappers used by GDB.
   2
   3    Copyright (C) 2011-2019 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 "common/gdb_ref_ptr.h"
  25
  26 DECLARE_REGISTRY (bfd);
  27
  28 /* If supplied a path starting with this sequence, gdb_bfd_open will
  29    open BFDs using target fileio operations.  */
  30
  31 #define TARGET_SYSROOT_PREFIX "target:"
  32
  33 /* Returns nonzero if NAME starts with TARGET_SYSROOT_PREFIX, zero
  34    otherwise.  */
  35
  36 int is_target_filename (const char *name);
  37
  38 /* Returns nonzero if the filename associated with ABFD starts with
  39    TARGET_SYSROOT_PREFIX, zero otherwise.  */
  40
  41 int gdb_bfd_has_target_filename (struct bfd *abfd);
  42
  43 /* Increment the reference count of ABFD.  It is fine for ABFD to be
  44    NULL; in this case the function does nothing.  */
  45
  46 void gdb_bfd_ref (struct bfd *abfd);
  47
  48 /* Decrement the reference count of ABFD.  If this is the last
  49    reference, ABFD will be freed.  If ABFD is NULL, this function does
  50    nothing.  */
  51
  52 void gdb_bfd_unref (struct bfd *abfd);
  53
  54 /* A policy class for gdb::ref_ptr for BFD reference counting.  */
  55 struct gdb_bfd_ref_policy
  56 {
  57   static void incref (struct bfd *abfd)
  58   {
  59     gdb_bfd_ref (abfd);
  60   }
  61
  62   static void decref (struct bfd *abfd)
  63   {
  64     gdb_bfd_unref (abfd);
  65   }
  66 };
  67
  68 /* A gdb::ref_ptr that has been specialized for BFD objects.  */
  69 typedef gdb::ref_ptr<struct bfd, gdb_bfd_ref_policy> gdb_bfd_ref_ptr;
  70
  71 /* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
  72    If NAME starts with TARGET_SYSROOT_PREFIX then the BFD will be
  73    opened using target fileio operations if necessary.  Returns NULL
  74    on error.  On success, returns a new reference to the BFD.  BFDs
  75    returned by this call are shared among all callers opening the same
  76    file.  If FD is not -1, then after this call it is owned by BFD.
  77    If the BFD was not accessed using target fileio operations then the
  78    filename associated with the BFD and accessible with
  79    bfd_get_filename will not be exactly NAME but rather NAME with
  80    TARGET_SYSROOT_PREFIX stripped.  */
  81
  82 gdb_bfd_ref_ptr gdb_bfd_open (const char *name, const char *target, int fd);
  83
  84 /* Mark the CHILD BFD as being a member of PARENT.  Also, increment
  85    the reference count of CHILD.  Calling this function ensures that
  86    as along as CHILD remains alive, PARENT will as well.  Both CHILD
  87    and PARENT must be non-NULL.  This can be called more than once
  88    with the same arguments; but it is not allowed to call it for a
  89    single CHILD with different values for PARENT.  */
  90
  91 void gdb_bfd_mark_parent (bfd *child, bfd *parent);
  92
  93 /* Mark INCLUDEE as being included by INCLUDER.
  94    This is used to associate the life time of INCLUDEE with INCLUDER.
  95    For example, with Fission, one file can refer to debug info in another
  96    file, and internal tables we build for the main file (INCLUDER) may refer
  97    to data contained in INCLUDEE.  Therefore we want to keep INCLUDEE around
  98    at least as long as INCLUDER exists.
  99
 100    Note that this is different than gdb_bfd_mark_parent because in our case
 101    lifetime tracking is based on the "parent" whereas in gdb_bfd_mark_parent
 102    lifetime tracking is based on the "child".  Plus in our case INCLUDEE could
 103    have multiple different "parents".  */
 104
 105 void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
 106
 107 /* Try to read or map the contents of the section SECT.  If successful, the
 108    section data is returned and *SIZE is set to the size of the section data;
 109    this may not be the same as the size according to bfd_get_section_size if the
 110    section was compressed.  The returned section data is associated with the BFD
 111    and will be destroyed when the BFD is destroyed.  There is no other way to
 112    free it; for temporary uses of section data, see bfd_malloc_and_get_section.
 113    SECT may not have relocations.  If there is an error reading the section,
 114    this issues a warning, sets *SIZE to 0, and returns NULL.  */
 115
 116 const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
 117
 118 /* Compute the CRC for ABFD.  The CRC is used to find and verify
 119    separate debug files.  When successful, this fills in *CRC_OUT and
 120    returns 1.  Otherwise, this issues a warning and returns 0.  */
 121
 122 int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
 123
 124 \f
 125
 126 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
 127    count.  */
 128
 129 gdb_bfd_ref_ptr gdb_bfd_fopen (const char *, const char *, const char *, int);
 130
 131 /* A wrapper for bfd_openr that initializes the gdb-specific reference
 132    count.  */
 133
 134 gdb_bfd_ref_ptr gdb_bfd_openr (const char *, const char *);
 135
 136 /* A wrapper for bfd_openw that initializes the gdb-specific reference
 137    count.  */
 138
 139 gdb_bfd_ref_ptr gdb_bfd_openw (const char *, const char *);
 140
 141 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
 142    reference count.  */
 143
 144 gdb_bfd_ref_ptr gdb_bfd_openr_iovec (const char *filename, const char *target,
 145                                      void *(*open_func) (struct bfd *nbfd,
 146                                                          void *open_closure),
 147                                      void *open_closure,
 148                                      file_ptr (*pread_func) (struct bfd *nbfd,
 149                                                              void *stream,
 150                                                              void *buf,
 151                                                              file_ptr nbytes,
 152                                                              file_ptr offset),
 153                                      int (*close_func) (struct bfd *nbfd,
 154                                                         void *stream),
 155                                      int (*stat_func) (struct bfd *abfd,
 156                                                        void *stream,
 157                                                        struct stat *sb));
 158
 159 /* A wrapper for bfd_openr_next_archived_file that initializes the
 160    gdb-specific reference count.  */
 161
 162 gdb_bfd_ref_ptr gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 163
 164 /* A wrapper for bfd_fdopenr that initializes the gdb-specific
 165    reference count.  */
 166
 167 gdb_bfd_ref_ptr gdb_bfd_fdopenr (const char *filename, const char *target,
 168                                  int fd);
 169
 170 \f
 171
 172 /* Return the index of the BFD section SECTION.  Ordinarily this is
 173    just the section's index, but for some special sections, like
 174    bfd_com_section_ptr, it will be a synthesized value.  */
 175
 176 int gdb_bfd_section_index (bfd *abfd, asection *section);
 177
 178
 179 /* Like bfd_count_sections, but include any possible global sections,
 180    like bfd_com_section_ptr.  */
 181
 182 int gdb_bfd_count_sections (bfd *abfd);
 183
 184 /* Return true if any section requires relocations, false
 185    otherwise.  */
 186
 187 int gdb_bfd_requires_relocations (bfd *abfd);
 188
 189 #endif /* GDB_BFD_H */