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"
39 struct program_space_data
;
40 struct address_space_data
;
43 typedef std::list
<std::shared_ptr
<objfile
>> objfile_list
;
45 /* An iterator that wraps an iterator over std::shared_ptr<objfile>,
46 and dereferences the returned object. This is useful for iterating
47 over a list of shared pointers and returning raw pointers -- which
48 helped avoid touching a lot of code when changing how objfiles are
51 class unwrapping_objfile_iterator
55 typedef unwrapping_objfile_iterator self_type
;
56 typedef typename ::objfile
*value_type
;
57 typedef typename ::objfile
&reference
;
58 typedef typename ::objfile
**pointer
;
59 typedef typename
objfile_list::iterator::iterator_category iterator_category
;
60 typedef typename
objfile_list::iterator::difference_type difference_type
;
62 unwrapping_objfile_iterator (const objfile_list::iterator
&iter
)
67 objfile
*operator* () const
69 return m_iter
->get ();
72 unwrapping_objfile_iterator
operator++ ()
78 bool operator!= (const unwrapping_objfile_iterator
&other
) const
80 return m_iter
!= other
.m_iter
;
85 /* The underlying iterator. */
86 objfile_list::iterator m_iter
;
90 /* A range that returns unwrapping_objfile_iterators. */
92 struct unwrapping_objfile_range
94 typedef unwrapping_objfile_iterator iterator
;
96 unwrapping_objfile_range (objfile_list
&ol
)
101 iterator
begin () const
103 return iterator (m_list
.begin ());
106 iterator
end () const
108 return iterator (m_list
.end ());
113 objfile_list
&m_list
;
116 /* A program space represents a symbolic view of an address space.
117 Roughly speaking, it holds all the data associated with a
118 non-running-yet program (main executable, main symbols), and when
119 an inferior is running and is bound to it, includes the list of its
120 mapped in shared libraries.
122 In the traditional debugging scenario, there's a 1-1 correspondence
123 among program spaces, inferiors and address spaces, like so:
125 pspace1 (prog1) <--> inf1(pid1) <--> aspace1
127 In the case of debugging more than one traditional unix process or
128 program, we still have:
130 |-----------------+------------+---------|
131 | pspace1 (prog1) | inf1(pid1) | aspace1 |
132 |----------------------------------------|
133 | pspace2 (prog1) | no inf yet | aspace2 |
134 |-----------------+------------+---------|
135 | pspace3 (prog2) | inf2(pid2) | aspace3 |
136 |-----------------+------------+---------|
138 In the former example, if inf1 forks (and GDB stays attached to
139 both processes), the new child will have its own program and
140 address spaces. Like so:
142 |-----------------+------------+---------|
143 | pspace1 (prog1) | inf1(pid1) | aspace1 |
144 |-----------------+------------+---------|
145 | pspace2 (prog1) | inf2(pid2) | aspace2 |
146 |-----------------+------------+---------|
148 However, had inf1 from the latter case vforked instead, it would
149 share the program and address spaces with its parent, until it
150 execs or exits, like so:
152 |-----------------+------------+---------|
153 | pspace1 (prog1) | inf1(pid1) | aspace1 |
155 |-----------------+------------+---------|
157 When the vfork child execs, it is finally given new program and
160 |-----------------+------------+---------|
161 | pspace1 (prog1) | inf1(pid1) | aspace1 |
162 |-----------------+------------+---------|
163 | pspace2 (prog1) | inf2(pid2) | aspace2 |
164 |-----------------+------------+---------|
166 There are targets where the OS (if any) doesn't provide memory
167 management or VM protection, where all inferiors share the same
168 address space --- e.g. uClinux. GDB models this by having all
169 inferiors share the same address space, but, giving each its own
170 program space, like so:
172 |-----------------+------------+---------|
173 | pspace1 (prog1) | inf1(pid1) | |
174 |-----------------+------------+ |
175 | pspace2 (prog1) | inf2(pid2) | aspace1 |
176 |-----------------+------------+ |
177 | pspace3 (prog2) | inf3(pid3) | |
178 |-----------------+------------+---------|
180 The address space sharing matters for run control and breakpoints
181 management. E.g., did we just hit a known breakpoint that we need
182 to step over? Is this breakpoint a duplicate of this other one, or
183 do I need to insert a trap?
185 Then, there are targets where all symbols look the same for all
186 inferiors, although each has its own address space, as e.g.,
187 Ericsson DICOS. In such case, the model is:
189 |---------+------------+---------|
190 | | inf1(pid1) | aspace1 |
191 | +------------+---------|
192 | pspace | inf2(pid2) | aspace2 |
193 | +------------+---------|
194 | | inf3(pid3) | aspace3 |
195 |---------+------------+---------|
197 Note however, that the DICOS debug API takes care of making GDB
198 believe that breakpoints are "global". That is, although each
199 process does have its own private copy of data symbols (just like a
200 bunch of forks), to the breakpoints module, all processes share a
201 single address space, so all breakpoints set at the same address
202 are duplicates of each other, even breakpoints set in the data
203 space (e.g., call dummy breakpoints placed on stack). This allows
204 a simplification in the spaces implementation: we avoid caring for
205 a many-many links between address and program spaces. Either
206 there's a single address space bound to the program space
207 (traditional unix/uClinux), or, in the DICOS case, the address
208 space bound to the program space is mostly ignored. */
210 /* The program space structure. */
214 /* Constructs a new empty program space, binds it to ASPACE, and
215 adds it to the program space list. */
216 explicit program_space (address_space
*aspace
);
218 /* Releases a program space, and all its contents (shared libraries,
219 objfiles, and any other references to the program space in other
220 modules). It is an internal error to call this when the program
221 space is the current program space, since there should always be
225 typedef unwrapping_objfile_range objfiles_range
;
227 /* Return an iterable object that can be used to iterate over all
228 objfiles. The basic use is in a foreach, like:
230 for (objfile *objf : pspace->objfiles ()) { ... } */
231 objfiles_range
objfiles ()
233 return unwrapping_objfile_range (objfiles_list
);
236 typedef basic_safe_range
<objfiles_range
> objfiles_safe_range
;
238 /* An iterable object that can be used to iterate over all objfiles.
239 The basic use is in a foreach, like:
241 for (objfile *objf : pspace->objfiles_safe ()) { ... }
243 This variant uses a basic_safe_iterator so that objfiles can be
244 deleted during iteration. */
245 objfiles_safe_range
objfiles_safe ()
247 return objfiles_safe_range (objfiles_list
);
250 /* Add OBJFILE to the list of objfiles, putting it just before
251 BEFORE. If BEFORE is nullptr, it will go at the end of the
253 void add_objfile (std::shared_ptr
<objfile
> &&objfile
,
254 struct objfile
*before
);
256 /* Remove OBJFILE from the list of objfiles. */
257 void remove_objfile (struct objfile
*objfile
);
259 /* Return true if there is more than one object file loaded; false
261 bool multi_objfile_p () const
263 return objfiles_list
.size () > 1;
266 /* Free all the objfiles associated with this program space. */
267 void free_all_objfiles ();
269 /* Return a range adapter for iterating over all the solibs in this
270 program space. Use it like:
272 for (so_list *so : pspace->solibs ()) { ... } */
273 next_adapter
<struct so_list
> solibs () const;
276 /* Unique ID number. */
279 /* The main executable loaded into this program space. This is
280 managed by the exec target. */
282 /* The BFD handle for the main executable. */
284 /* The last-modified time, from when the exec was brought in. */
286 /* Similar to bfd_get_filename (exec_bfd) but in original form given
287 by user, without symbolic links and pathname resolved.
288 It needs to be freed by xfree. It is not NULL iff EBFD is not NULL. */
289 char *pspace_exec_filename
= NULL
;
291 /* Binary file diddling handle for the core file. */
292 gdb_bfd_ref_ptr cbfd
;
294 /* The address space attached to this program space. More than one
295 program space may be bound to the same address space. In the
296 traditional unix-like debugging scenario, this will usually
297 match the address space bound to the inferior, and is mostly
298 used by the breakpoints module for address matches. If the
299 target shares a program space for all inferiors and breakpoints
300 are global, then this field is ignored (we don't currently
301 support inferiors sharing a program space if the target doesn't
302 make breakpoints global). */
303 struct address_space
*aspace
= NULL
;
305 /* True if this program space's section offsets don't yet represent
306 the final offsets of the "live" address space (that is, the
307 section addresses still require the relocation offsets to be
308 applied, and hence we can't trust the section addresses for
309 anything that pokes at live memory). E.g., for qOffsets
310 targets, or for PIE executables, until we connect and ask the
311 target for the final relocation offsets, the symbols we've used
312 to set breakpoints point at the wrong addresses. */
313 int executing_startup
= 0;
315 /* True if no breakpoints should be inserted in this program
317 int breakpoints_not_allowed
= 0;
319 /* The object file that the main symbol table was loaded from
320 (e.g. the argument to the "symbol-file" or "file" command). */
321 struct objfile
*symfile_object_file
= NULL
;
323 /* All known objfiles are kept in a linked list. */
324 std::list
<std::shared_ptr
<objfile
>> objfiles_list
;
326 /* The set of target sections matching the sections mapped into
327 this program space. Managed by both exec_ops and solib.c. */
328 struct target_section_table target_sections
{};
330 /* List of shared objects mapped into this space. Managed by
332 struct so_list
*so_list
= NULL
;
334 /* Number of calls to solib_add. */
335 unsigned int solib_add_generation
= 0;
337 /* When an solib is added, it is also added to this vector. This
338 is so we can properly report solib changes to the user. */
339 std::vector
<struct so_list
*> added_solibs
;
341 /* When an solib is removed, its name is added to this vector.
342 This is so we can properly report solib changes to the user. */
343 std::vector
<std::string
> deleted_solibs
;
345 /* Per pspace data-pointers required by other GDB modules. */
349 /* An address space. It is used for comparing if
350 pspaces/inferior/threads see the same address space and for
351 associating caches to each address space. */
356 /* Per aspace data-pointers required by other GDB modules. */
360 /* The object file that the main symbol table was loaded from (e.g. the
361 argument to the "symbol-file" or "file" command). */
363 #define symfile_objfile current_program_space->symfile_object_file
365 /* The set of target sections matching the sections mapped into the
366 current program space. */
367 #define current_target_sections (¤t_program_space->target_sections)
369 /* The list of all program spaces. There's always at least one. */
370 extern std::vector
<struct program_space
*>program_spaces
;
372 /* The current program space. This is always non-null. */
373 extern struct program_space
*current_program_space
;
375 /* Returns true iff there's no inferior bound to PSPACE. */
376 extern int program_space_empty_p (struct program_space
*pspace
);
378 /* Copies program space SRC to DEST. Copies the main executable file,
379 and the main symbol file. Returns DEST. */
380 extern struct program_space
*clone_program_space (struct program_space
*dest
,
381 struct program_space
*src
);
383 /* Sets PSPACE as the current program space. This is usually used
384 instead of set_current_space_and_thread when the current
385 thread/inferior is not important for the operations that follow.
386 E.g., when accessing the raw symbol tables. If memory access is
387 required, then you should use switch_to_program_space_and_thread.
388 Otherwise, it is the caller's responsibility to make sure that the
389 currently selected inferior/thread matches the selected program
391 extern void set_current_program_space (struct program_space
*pspace
);
393 /* Save/restore the current program space. */
395 class scoped_restore_current_program_space
398 scoped_restore_current_program_space ()
399 : m_saved_pspace (current_program_space
)
402 ~scoped_restore_current_program_space ()
403 { set_current_program_space (m_saved_pspace
); }
405 DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space
);
408 program_space
*m_saved_pspace
;
411 /* Create a new address space object, and add it to the list. */
412 extern struct address_space
*new_address_space (void);
414 /* Maybe create a new address space object, and add it to the list, or
415 return a pointer to an existing address space, in case inferiors
416 share an address space. */
417 extern struct address_space
*maybe_new_address_space (void);
419 /* Returns the integer address space id of ASPACE. */
420 extern int address_space_num (struct address_space
*aspace
);
422 /* Update all program spaces matching to address spaces. The user may
423 have created several program spaces, and loaded executables into
424 them before connecting to the target interface that will create the
425 inferiors. All that happens before GDB has a chance to know if the
426 inferiors will share an address space or not. Call this after
427 having connected to the target interface and having fetched the
428 target description, to fixup the program/address spaces
430 extern void update_address_spaces (void);
432 /* Reset saved solib data at the start of an solib event. This lets
433 us properly collect the data when calling solib_add, so it can then
435 extern void clear_program_space_solib_cache (struct program_space
*);
437 /* Keep a registry of per-pspace data-pointers required by other GDB
440 DECLARE_REGISTRY (program_space
);
442 /* Keep a registry of per-aspace data-pointers required by other GDB
445 DECLARE_REGISTRY (address_space
);