1 /* Program and address space management, for GDB, the GNU debugger.
3 Copyright (C) 2009-2020 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
26 #include "gdbsupport/gdb_vecs.h"
28 #include "gdbsupport/next-iterator.h"
29 #include "gdbsupport/safe-iterator.h"
38 struct program_space_data
;
39 struct address_space_data
;
41 typedef std::list
<std::shared_ptr
<objfile
>> objfile_list
;
43 /* An iterator that wraps an iterator over std::shared_ptr<objfile>,
44 and dereferences the returned object. This is useful for iterating
45 over a list of shared pointers and returning raw pointers -- which
46 helped avoid touching a lot of code when changing how objfiles are
49 class unwrapping_objfile_iterator
53 typedef unwrapping_objfile_iterator self_type
;
54 typedef typename ::objfile
*value_type
;
55 typedef typename ::objfile
&reference
;
56 typedef typename ::objfile
**pointer
;
57 typedef typename
objfile_list::iterator::iterator_category iterator_category
;
58 typedef typename
objfile_list::iterator::difference_type difference_type
;
60 unwrapping_objfile_iterator (const objfile_list::iterator
&iter
)
65 objfile
*operator* () const
67 return m_iter
->get ();
70 unwrapping_objfile_iterator
operator++ ()
76 bool operator!= (const unwrapping_objfile_iterator
&other
) const
78 return m_iter
!= other
.m_iter
;
83 /* The underlying iterator. */
84 objfile_list::iterator m_iter
;
88 /* A range that returns unwrapping_objfile_iterators. */
90 struct unwrapping_objfile_range
92 typedef unwrapping_objfile_iterator iterator
;
94 unwrapping_objfile_range (objfile_list
&ol
)
99 iterator
begin () const
101 return iterator (m_list
.begin ());
104 iterator
end () const
106 return iterator (m_list
.end ());
111 objfile_list
&m_list
;
114 /* A program space represents a symbolic view of an address space.
115 Roughly speaking, it holds all the data associated with a
116 non-running-yet program (main executable, main symbols), and when
117 an inferior is running and is bound to it, includes the list of its
118 mapped in shared libraries.
120 In the traditional debugging scenario, there's a 1-1 correspondence
121 among program spaces, inferiors and address spaces, like so:
123 pspace1 (prog1) <--> inf1(pid1) <--> aspace1
125 In the case of debugging more than one traditional unix process or
126 program, we still have:
128 |-----------------+------------+---------|
129 | pspace1 (prog1) | inf1(pid1) | aspace1 |
130 |----------------------------------------|
131 | pspace2 (prog1) | no inf yet | aspace2 |
132 |-----------------+------------+---------|
133 | pspace3 (prog2) | inf2(pid2) | aspace3 |
134 |-----------------+------------+---------|
136 In the former example, if inf1 forks (and GDB stays attached to
137 both processes), the new child will have its own program and
138 address spaces. Like so:
140 |-----------------+------------+---------|
141 | pspace1 (prog1) | inf1(pid1) | aspace1 |
142 |-----------------+------------+---------|
143 | pspace2 (prog1) | inf2(pid2) | aspace2 |
144 |-----------------+------------+---------|
146 However, had inf1 from the latter case vforked instead, it would
147 share the program and address spaces with its parent, until it
148 execs or exits, like so:
150 |-----------------+------------+---------|
151 | pspace1 (prog1) | inf1(pid1) | aspace1 |
153 |-----------------+------------+---------|
155 When the vfork child execs, it is finally given new program and
158 |-----------------+------------+---------|
159 | pspace1 (prog1) | inf1(pid1) | aspace1 |
160 |-----------------+------------+---------|
161 | pspace2 (prog1) | inf2(pid2) | aspace2 |
162 |-----------------+------------+---------|
164 There are targets where the OS (if any) doesn't provide memory
165 management or VM protection, where all inferiors share the same
166 address space --- e.g. uClinux. GDB models this by having all
167 inferiors share the same address space, but, giving each its own
168 program space, like so:
170 |-----------------+------------+---------|
171 | pspace1 (prog1) | inf1(pid1) | |
172 |-----------------+------------+ |
173 | pspace2 (prog1) | inf2(pid2) | aspace1 |
174 |-----------------+------------+ |
175 | pspace3 (prog2) | inf3(pid3) | |
176 |-----------------+------------+---------|
178 The address space sharing matters for run control and breakpoints
179 management. E.g., did we just hit a known breakpoint that we need
180 to step over? Is this breakpoint a duplicate of this other one, or
181 do I need to insert a trap?
183 Then, there are targets where all symbols look the same for all
184 inferiors, although each has its own address space, as e.g.,
185 Ericsson DICOS. In such case, the model is:
187 |---------+------------+---------|
188 | | inf1(pid1) | aspace1 |
189 | +------------+---------|
190 | pspace | inf2(pid2) | aspace2 |
191 | +------------+---------|
192 | | inf3(pid3) | aspace3 |
193 |---------+------------+---------|
195 Note however, that the DICOS debug API takes care of making GDB
196 believe that breakpoints are "global". That is, although each
197 process does have its own private copy of data symbols (just like a
198 bunch of forks), to the breakpoints module, all processes share a
199 single address space, so all breakpoints set at the same address
200 are duplicates of each other, even breakpoints set in the data
201 space (e.g., call dummy breakpoints placed on stack). This allows
202 a simplification in the spaces implementation: we avoid caring for
203 a many-many links between address and program spaces. Either
204 there's a single address space bound to the program space
205 (traditional unix/uClinux), or, in the DICOS case, the address
206 space bound to the program space is mostly ignored. */
208 /* The program space structure. */
212 /* Constructs a new empty program space, binds it to ASPACE, and
213 adds it to the program space list. */
214 explicit program_space (address_space
*aspace
);
216 /* Releases a program space, and all its contents (shared libraries,
217 objfiles, and any other references to the program space in other
218 modules). It is an internal error to call this when the program
219 space is the current program space, since there should always be
223 typedef unwrapping_objfile_range objfiles_range
;
225 /* Return an iterable object that can be used to iterate over all
226 objfiles. The basic use is in a foreach, like:
228 for (objfile *objf : pspace->objfiles ()) { ... } */
229 objfiles_range
objfiles ()
231 return unwrapping_objfile_range (objfiles_list
);
234 typedef basic_safe_range
<objfiles_range
> objfiles_safe_range
;
236 /* An iterable object that can be used to iterate over all objfiles.
237 The basic use is in a foreach, like:
239 for (objfile *objf : pspace->objfiles_safe ()) { ... }
241 This variant uses a basic_safe_iterator so that objfiles can be
242 deleted during iteration. */
243 objfiles_safe_range
objfiles_safe ()
245 return objfiles_safe_range (objfiles_list
);
248 /* Add OBJFILE to the list of objfiles, putting it just before
249 BEFORE. If BEFORE is nullptr, it will go at the end of the
251 void add_objfile (std::shared_ptr
<objfile
> &&objfile
,
252 struct objfile
*before
);
254 /* Remove OBJFILE from the list of objfiles. */
255 void remove_objfile (struct objfile
*objfile
);
257 /* Return true if there is more than one object file loaded; false
259 bool multi_objfile_p () const
261 return objfiles_list
.size () > 1;
264 /* Free all the objfiles associated with this program space. */
265 void free_all_objfiles ();
268 /* Pointer to next in linked list. */
269 struct program_space
*next
= NULL
;
271 /* Unique ID number. */
274 /* The main executable loaded into this program space. This is
275 managed by the exec target. */
277 /* The BFD handle for the main executable. */
279 /* The last-modified time, from when the exec was brought in. */
281 /* Similar to bfd_get_filename (exec_bfd) but in original form given
282 by user, without symbolic links and pathname resolved.
283 It needs to be freed by xfree. It is not NULL iff EBFD is not NULL. */
284 char *pspace_exec_filename
= NULL
;
286 /* Binary file diddling handle for the core file. */
287 gdb_bfd_ref_ptr cbfd
;
289 /* The address space attached to this program space. More than one
290 program space may be bound to the same address space. In the
291 traditional unix-like debugging scenario, this will usually
292 match the address space bound to the inferior, and is mostly
293 used by the breakpoints module for address matches. If the
294 target shares a program space for all inferiors and breakpoints
295 are global, then this field is ignored (we don't currently
296 support inferiors sharing a program space if the target doesn't
297 make breakpoints global). */
298 struct address_space
*aspace
= NULL
;
300 /* True if this program space's section offsets don't yet represent
301 the final offsets of the "live" address space (that is, the
302 section addresses still require the relocation offsets to be
303 applied, and hence we can't trust the section addresses for
304 anything that pokes at live memory). E.g., for qOffsets
305 targets, or for PIE executables, until we connect and ask the
306 target for the final relocation offsets, the symbols we've used
307 to set breakpoints point at the wrong addresses. */
308 int executing_startup
= 0;
310 /* True if no breakpoints should be inserted in this program
312 int breakpoints_not_allowed
= 0;
314 /* The object file that the main symbol table was loaded from
315 (e.g. the argument to the "symbol-file" or "file" command). */
316 struct objfile
*symfile_object_file
= NULL
;
318 /* All known objfiles are kept in a linked list. */
319 std::list
<std::shared_ptr
<objfile
>> objfiles_list
;
321 /* The set of target sections matching the sections mapped into
322 this program space. Managed by both exec_ops and solib.c. */
323 struct target_section_table target_sections
{};
325 /* List of shared objects mapped into this space. Managed by
327 struct so_list
*so_list
= NULL
;
329 /* Number of calls to solib_add. */
330 unsigned int solib_add_generation
= 0;
332 /* When an solib is added, it is also added to this vector. This
333 is so we can properly report solib changes to the user. */
334 std::vector
<struct so_list
*> added_solibs
;
336 /* When an solib is removed, its name is added to this vector.
337 This is so we can properly report solib changes to the user. */
338 std::vector
<std::string
> deleted_solibs
;
340 /* Per pspace data-pointers required by other GDB modules. */
344 /* An address space. It is used for comparing if
345 pspaces/inferior/threads see the same address space and for
346 associating caches to each address space. */
351 /* Per aspace data-pointers required by other GDB modules. */
355 /* The object file that the main symbol table was loaded from (e.g. the
356 argument to the "symbol-file" or "file" command). */
358 #define symfile_objfile current_program_space->symfile_object_file
360 /* The set of target sections matching the sections mapped into the
361 current program space. */
362 #define current_target_sections (¤t_program_space->target_sections)
364 /* The list of all program spaces. There's always at least one. */
365 extern struct program_space
*program_spaces
;
367 /* The current program space. This is always non-null. */
368 extern struct program_space
*current_program_space
;
370 #define ALL_PSPACES(pspace) \
371 for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next)
373 /* Returns the number of program spaces listed. */
374 extern int number_of_program_spaces (void);
376 /* Returns true iff there's no inferior bound to PSPACE. */
377 extern int program_space_empty_p (struct program_space
*pspace
);
379 /* Copies program space SRC to DEST. Copies the main executable file,
380 and the main symbol file. Returns DEST. */
381 extern struct program_space
*clone_program_space (struct program_space
*dest
,
382 struct program_space
*src
);
384 /* Sets PSPACE as the current program space. This is usually used
385 instead of set_current_space_and_thread when the current
386 thread/inferior is not important for the operations that follow.
387 E.g., when accessing the raw symbol tables. If memory access is
388 required, then you should use switch_to_program_space_and_thread.
389 Otherwise, it is the caller's responsibility to make sure that the
390 currently selected inferior/thread matches the selected program
392 extern void set_current_program_space (struct program_space
*pspace
);
394 /* Save/restore the current program space. */
396 class scoped_restore_current_program_space
399 scoped_restore_current_program_space ()
400 : m_saved_pspace (current_program_space
)
403 ~scoped_restore_current_program_space ()
404 { set_current_program_space (m_saved_pspace
); }
406 DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space
);
409 program_space
*m_saved_pspace
;
412 /* Create a new address space object, and add it to the list. */
413 extern struct address_space
*new_address_space (void);
415 /* Maybe create a new address space object, and add it to the list, or
416 return a pointer to an existing address space, in case inferiors
417 share an address space. */
418 extern struct address_space
*maybe_new_address_space (void);
420 /* Returns the integer address space id of ASPACE. */
421 extern int address_space_num (struct address_space
*aspace
);
423 /* Update all program spaces matching to address spaces. The user may
424 have created several program spaces, and loaded executables into
425 them before connecting to the target interface that will create the
426 inferiors. All that happens before GDB has a chance to know if the
427 inferiors will share an address space or not. Call this after
428 having connected to the target interface and having fetched the
429 target description, to fixup the program/address spaces
431 extern void update_address_spaces (void);
433 /* Reset saved solib data at the start of an solib event. This lets
434 us properly collect the data when calling solib_add, so it can then
436 extern void clear_program_space_solib_cache (struct program_space
*);
438 /* Keep a registry of per-pspace data-pointers required by other GDB
441 DECLARE_REGISTRY (program_space
);
443 /* Keep a registry of per-aspace data-pointers required by other GDB
446 DECLARE_REGISTRY (address_space
);