gdb/solist.h

   1 /* Shared library declarations for GDB, the GNU Debugger.
   2    Copyright (C) 1990-2024 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef SOLIST_H
  20 #define SOLIST_H
  21
  22 #define SO_NAME_MAX_PATH_SIZE 512       /* FIXME: Should be dynamic */
  23
  24 /* For domain_enum domain.  */
  25 #include "symtab.h"
  26 #include "gdb_bfd.h"
  27 #include "gdbsupport/owning_intrusive_list.h"
  28 #include "target-section.h"
  29
  30 /* Base class for target-specific link map information.  */
  31
  32 struct lm_info
  33 {
  34   lm_info () = default;
  35   lm_info (const lm_info &) = default;
  36   virtual ~lm_info () = 0;
  37 };
  38
  39 using lm_info_up = std::unique_ptr<lm_info>;
  40
  41 struct solib : intrusive_list_node<solib>
  42 {
  43   /* Free symbol-file related contents of SO and reset for possible reloading
  44      of SO.  If we have opened a BFD for SO, close it.  If we have placed SO's
  45      sections in some target's section table, the caller is responsible for
  46      removing them.
  47
  48      This function doesn't mess with objfiles at all.  If there is an
  49      objfile associated with SO that needs to be removed, the caller is
  50      responsible for taking care of that.  */
  51   void clear () ;
  52
  53   /* The following fields of the structure come directly from the
  54      dynamic linker's tables in the inferior, and are initialized by
  55      current_sos.  */
  56
  57   /* A pointer to target specific link map information.  Often this
  58      will be a copy of struct link_map from the user process, but
  59      it need not be; it can be any collection of data needed to
  60      traverse the dynamic linker's data structures.  */
  61   lm_info_up lm_info;
  62
  63   /* Shared object file name, exactly as it appears in the
  64      inferior's link map.  This may be a relative path, or something
  65      which needs to be looked up in LD_LIBRARY_PATH, etc.  We use it
  66      to tell which entries in the inferior's dynamic linker's link
  67      map we've already loaded.  */
  68   std::string so_original_name;
  69
  70   /* Shared object file name, expanded to something GDB can open.  */
  71   std::string so_name;
  72
  73   /* The following fields of the structure are built from
  74      information gathered from the shared object file itself, and
  75      are set when we actually add it to our symbol tables.
  76
  77      current_sos must initialize these fields to 0.  */
  78
  79   gdb_bfd_ref_ptr abfd;
  80
  81   /* True if symbols have been read in.  */
  82   bool symbols_loaded = false;
  83
  84   /* objfile with symbols for a loaded library.  Target memory is read from
  85      ABFD.  OBJFILE may be NULL either before symbols have been loaded, if
  86      the file cannot be found or after the command "nosharedlibrary".  */
  87   struct objfile *objfile = nullptr;
  88
  89   std::vector<target_section> sections;
  90
  91   /* Record the range of addresses belonging to this shared library.
  92      There may not be just one (e.g. if two segments are relocated
  93      differently).  This is used for "info sharedlibrary" and
  94      the MI command "-file-list-shared-libraries".  The latter has a format
  95      that supports outputting multiple segments once the related code
  96      supports them.  */
  97   CORE_ADDR addr_low = 0, addr_high = 0;
  98 };
  99
 100 struct solib_ops
 101 {
 102   /* Adjust the section binding addresses by the base address at
 103      which the object was actually mapped.  */
 104   void (*relocate_section_addresses) (solib &so, target_section *);
 105
 106   /* Reset private data structures associated with SO.
 107      This is called when SO is about to be reloaded.
 108      It is also called when SO is about to be freed.  */
 109   void (*clear_so) (const solib &so);
 110
 111   /* Free private data structures associated to PSPACE.  This method
 112      should not free resources associated to individual so_list entries,
 113      those are cleared by the clear_so method.  */
 114   void (*clear_solib) (program_space *pspace);
 115
 116   /* Target dependent code to run after child process fork.  */
 117   void (*solib_create_inferior_hook) (int from_tty);
 118
 119   /* Construct a list of the currently loaded shared objects.  This
 120      list does not include an entry for the main executable file.
 121
 122      Note that we only gather information directly available from the
 123      inferior --- we don't examine any of the shared library files
 124      themselves.  The declaration of `struct solib' says which fields
 125      we provide values for.  */
 126   owning_intrusive_list<solib> (*current_sos) ();
 127
 128   /* Find, open, and read the symbols for the main executable.  If
 129      FROM_TTY is non-zero, allow messages to be printed.  */
 130   int (*open_symbol_file_object) (int from_ttyp);
 131
 132   /* Determine if PC lies in the dynamic symbol resolution code of
 133      the run time loader.  */
 134   int (*in_dynsym_resolve_code) (CORE_ADDR pc);
 135
 136   /* Find and open shared library binary file.  */
 137   gdb_bfd_ref_ptr (*bfd_open) (const char *pathname);
 138
 139   /* Given two so_list objects, one from the GDB thread list
 140      and another from the list returned by current_sos, return 1
 141      if they represent the same library.
 142      Falls back to using strcmp on so_original_name field when set
 143      to NULL.  */
 144   int (*same) (const solib &gdb, const solib &inferior);
 145
 146   /* Return whether a region of memory must be kept in a core file
 147      for shared libraries loaded before "gcore" is used to be
 148      handled correctly when the core file is loaded.  This only
 149      applies when the section would otherwise not be kept in the
 150      core file (in particular, for readonly sections).  */
 151   int (*keep_data_in_core) (CORE_ADDR vaddr,
 152                             unsigned long size);
 153
 154   /* Enable or disable optional solib event breakpoints as
 155      appropriate.  This should be called whenever
 156      stop_on_solib_events is changed.  This pointer can be
 157      NULL, in which case no enabling or disabling is necessary
 158      for this target.  */
 159   void (*update_breakpoints) (void);
 160
 161   /* Target-specific processing of solib events that will be
 162      performed before solib_add is called.  This pointer can be
 163      NULL, in which case no specific preprocessing is necessary
 164      for this target.  */
 165   void (*handle_event) (void);
 166
 167   /* Return an address within the inferior's address space which is known
 168      to be part of SO.  If there is no such address, or GDB doesn't know
 169      how to figure out such an address then an empty optional is
 170      returned.
 171
 172      The returned address can be used when loading the shared libraries
 173      for a core file.  GDB knows the build-ids for (some) files mapped
 174      into the inferior's address space, and knows the address ranges which
 175      those mapped files cover.  If GDB can figure out a representative
 176      address for the library then this can be used to match a library to a
 177      mapped file, and thus to a build-id.  GDB can then use this
 178      information to help locate the shared library objfile, if the objfile
 179      is not in the expected place (as defined by the shared libraries file
 180      name).  */
 181
 182   std::optional<CORE_ADDR> (*find_solib_addr) (solib &so);
 183 };
 184
 185 /* A unique pointer to a so_list.  */
 186 using solib_up = std::unique_ptr<solib>;
 187
 188 /* Find main executable binary file.  */
 189 extern gdb::unique_xmalloc_ptr<char> exec_file_find (const char *in_pathname,
 190                                                      int *fd);
 191
 192 /* Find shared library binary file.  */
 193 extern gdb::unique_xmalloc_ptr<char> solib_find (const char *in_pathname,
 194                                                  int *fd);
 195
 196 /* Open BFD for shared library file.  */
 197 extern gdb_bfd_ref_ptr solib_bfd_fopen (const char *pathname, int fd);
 198
 199 /* Find solib binary file and open it.  */
 200 extern gdb_bfd_ref_ptr solib_bfd_open (const char *in_pathname);
 201
 202 /* A default implementation of the solib_ops::find_solib_addr callback.
 203    This just returns an empty std::optional<CORE_ADDR> indicating GDB is
 204    unable to find an address within the library SO.  */
 205 extern std::optional<CORE_ADDR> default_find_solib_addr (solib &so);
 206
 207 #endif