GDB (xrefs)

/tmp/gdb-8.1/gdb/progspace.h
Go to the documentation of this file.
1 /* Program and address space management, for GDB, the GNU debugger.
2
3 Copyright (C) 2009-2018 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
21 #ifndef PROGSPACE_H
22 #define PROGSPACE_H
23
24 #include "target.h"
25 #include "vec.h"
26 #include "gdb_vecs.h"
27 #include "registry.h"
28
29 struct target_ops;
30 struct bfd;
31 struct objfile;
32 struct inferior;
33 struct exec;
34 struct address_space;
35 struct program_space_data;
36 struct address_space_data;
37
38 typedef struct so_list *so_list_ptr;
39 DEF_VEC_P (so_list_ptr);
40
41 /* A program space represents a symbolic view of an address space.
42 Roughly speaking, it holds all the data associated with a
43 non-running-yet program (main executable, main symbols), and when
44 an inferior is running and is bound to it, includes the list of its
45 mapped in shared libraries.
46
47 In the traditional debugging scenario, there's a 1-1 correspondence
48 among program spaces, inferiors and address spaces, like so:
49
50 pspace1 (prog1) <--> inf1(pid1) <--> aspace1
51
52 In the case of debugging more than one traditional unix process or
53 program, we still have:
54
55 |-----------------+------------+---------|
56 | pspace1 (prog1) | inf1(pid1) | aspace1 |
57 |----------------------------------------|
58 | pspace2 (prog1) | no inf yet | aspace2 |
59 |-----------------+------------+---------|
60 | pspace3 (prog2) | inf2(pid2) | aspace3 |
61 |-----------------+------------+---------|
62
63 In the former example, if inf1 forks (and GDB stays attached to
64 both processes), the new child will have its own program and
65 address spaces. Like so:
66
67 |-----------------+------------+---------|
68 | pspace1 (prog1) | inf1(pid1) | aspace1 |
69 |-----------------+------------+---------|
70 | pspace2 (prog1) | inf2(pid2) | aspace2 |
71 |-----------------+------------+---------|
72
73 However, had inf1 from the latter case vforked instead, it would
74 share the program and address spaces with its parent, until it
75 execs or exits, like so:
76
77 |-----------------+------------+---------|
78 | pspace1 (prog1) | inf1(pid1) | aspace1 |
79 | | inf2(pid2) | |
80 |-----------------+------------+---------|
81
82 When the vfork child execs, it is finally given new program and
83 address spaces.
84
85 |-----------------+------------+---------|
86 | pspace1 (prog1) | inf1(pid1) | aspace1 |
87 |-----------------+------------+---------|
88 | pspace2 (prog1) | inf2(pid2) | aspace2 |
89 |-----------------+------------+---------|
90
91 There are targets where the OS (if any) doesn't provide memory
92 management or VM protection, where all inferiors share the same
93 address space --- e.g. uClinux. GDB models this by having all
94 inferiors share the same address space, but, giving each its own
95 program space, like so:
96
97 |-----------------+------------+---------|
98 | pspace1 (prog1) | inf1(pid1) | |
99 |-----------------+------------+ |
100 | pspace2 (prog1) | inf2(pid2) | aspace1 |
101 |-----------------+------------+ |
102 | pspace3 (prog2) | inf3(pid3) | |
103 |-----------------+------------+---------|
104
105 The address space sharing matters for run control and breakpoints
106 management. E.g., did we just hit a known breakpoint that we need
107 to step over? Is this breakpoint a duplicate of this other one, or
108 do I need to insert a trap?
109
110 Then, there are targets where all symbols look the same for all
111 inferiors, although each has its own address space, as e.g.,
112 Ericsson DICOS. In such case, the model is:
113
114 |---------+------------+---------|
115 | | inf1(pid1) | aspace1 |
116 | +------------+---------|
117 | pspace | inf2(pid2) | aspace2 |
118 | +------------+---------|
119 | | inf3(pid3) | aspace3 |
120 |---------+------------+---------|
121
122 Note however, that the DICOS debug API takes care of making GDB
123 believe that breakpoints are "global". That is, although each
124 process does have its own private copy of data symbols (just like a
125 bunch of forks), to the breakpoints module, all processes share a
126 single address space, so all breakpoints set at the same address
127 are duplicates of each other, even breakpoints set in the data
128 space (e.g., call dummy breakpoints placed on stack). This allows
129 a simplification in the spaces implementation: we avoid caring for
130 a many-many links between address and program spaces. Either
131 there's a single address space bound to the program space
132 (traditional unix/uClinux), or, in the DICOS case, the address
133 space bound to the program space is mostly ignored. */
134
135 /* The program space structure. */
136
137 struct program_space
138 {
139 /* Pointer to next in linked list. */
140 struct program_space *next;
141
142 /* Unique ID number. */
143 int num;
144
145 /* The main executable loaded into this program space. This is
146 managed by the exec target. */
147
148 /* The BFD handle for the main executable. */
149 bfd *ebfd;
150 /* The last-modified time, from when the exec was brought in. */
151 long ebfd_mtime;
152 /* Similar to bfd_get_filename (exec_bfd) but in original form given
153 by user, without symbolic links and pathname resolved.
154 It needs to be freed by xfree. It is not NULL iff EBFD is not NULL. */
155 char *pspace_exec_filename;
156
157 /* The address space attached to this program space. More than one
158 program space may be bound to the same address space. In the
159 traditional unix-like debugging scenario, this will usually
160 match the address space bound to the inferior, and is mostly
161 used by the breakpoints module for address matches. If the
162 target shares a program space for all inferiors and breakpoints
163 are global, then this field is ignored (we don't currently
164 support inferiors sharing a program space if the target doesn't
165 make breakpoints global). */
166 struct address_space *aspace;
167
168 /* True if this program space's section offsets don't yet represent
169 the final offsets of the "live" address space (that is, the
170 section addresses still require the relocation offsets to be
171 applied, and hence we can't trust the section addresses for
172 anything that pokes at live memory). E.g., for qOffsets
173 targets, or for PIE executables, until we connect and ask the
174 target for the final relocation offsets, the symbols we've used
175 to set breakpoints point at the wrong addresses. */
176 int executing_startup;
177
178 /* True if no breakpoints should be inserted in this program
179 space. */
180 int breakpoints_not_allowed;
181
182 /* The object file that the main symbol table was loaded from
183 (e.g. the argument to the "symbol-file" or "file" command). */
184 struct objfile *symfile_object_file;
185
186 /* All known objfiles are kept in a linked list. This points to
187 the head of this list. */
188 struct objfile *objfiles;
189
190 /* The set of target sections matching the sections mapped into
191 this program space. Managed by both exec_ops and solib.c. */
192 struct target_section_table target_sections;
193
194 /* List of shared objects mapped into this space. Managed by
195 solib.c. */
196 struct so_list *so_list;
197
198 /* Number of calls to solib_add. */
199 unsigned solib_add_generation;
200
201 /* When an solib is added, it is also added to this vector. This
202 is so we can properly report solib changes to the user. */
203 VEC (so_list_ptr) *added_solibs;
204
205 /* When an solib is removed, its name is added to this vector.
206 This is so we can properly report solib changes to the user. */
207 VEC (char_ptr) *deleted_solibs;
208
209 /* Per pspace data-pointers required by other GDB modules. */
210 REGISTRY_FIELDS;
211 };
212
213 /* An address space. It is used for comparing if
214 pspaces/inferior/threads see the same address space and for
215 associating caches to each address space. */
216 struct address_space
217 {
218 int num;
219
220 /* Per aspace data-pointers required by other GDB modules. */
221 REGISTRY_FIELDS;
222 };
223
224 /* The object file that the main symbol table was loaded from (e.g. the
225 argument to the "symbol-file" or "file" command). */
226
227 #define symfile_objfile current_program_space->symfile_object_file
228
229 /* All known objfiles are kept in a linked list. This points to the
230 root of this list. */
231 #define object_files current_program_space->objfiles
232
233 /* The set of target sections matching the sections mapped into the
234 current program space. */
235 #define current_target_sections (&current_program_space->target_sections)
236
237 /* The list of all program spaces. There's always at least one. */
238 extern struct program_space *program_spaces;
239
240 /* The current program space. This is always non-null. */
241 extern struct program_space *current_program_space;
242
243 #define ALL_PSPACES(pspace) \
244 for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next)
245
246 /* Add a new empty program space, and assign ASPACE to it. Returns the
247 pointer to the new object. */
248 extern struct program_space *add_program_space (struct address_space *aspace);
249
250 /* Remove a program space from the program spaces list and release it. It is
251 an error to call this function while PSPACE is the current program space. */
252 extern void delete_program_space (struct program_space *pspace);
253
254 /* Returns the number of program spaces listed. */
255 extern int number_of_program_spaces (void);
256
257 /* Returns true iff there's no inferior bound to PSPACE. */
258 extern int program_space_empty_p (struct program_space *pspace);
259
260 /* Copies program space SRC to DEST. Copies the main executable file,
261 and the main symbol file. Returns DEST. */
262 extern struct program_space *clone_program_space (struct program_space *dest,
263 struct program_space *src);
264
265 /* Sets PSPACE as the current program space. This is usually used
266 instead of set_current_space_and_thread when the current
267 thread/inferior is not important for the operations that follow.
268 E.g., when accessing the raw symbol tables. If memory access is
269 required, then you should use switch_to_program_space_and_thread.
270 Otherwise, it is the caller's responsibility to make sure that the
271 currently selected inferior/thread matches the selected program
272 space. */
273 extern void set_current_program_space (struct program_space *pspace);
274
275 /* Save/restore the current program space. */
276
277 class scoped_restore_current_program_space
278 {
279 public:
280 scoped_restore_current_program_space ()
281 : m_saved_pspace (current_program_space)
282 {}
283
284 ~scoped_restore_current_program_space ()
285 { set_current_program_space (m_saved_pspace); }
286
287 DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space);
288
289 private:
290 program_space *m_saved_pspace;
291 };
292
293 /* Create a new address space object, and add it to the list. */
294 extern struct address_space *new_address_space (void);
295
296 /* Maybe create a new address space object, and add it to the list, or
297 return a pointer to an existing address space, in case inferiors
298 share an address space. */
299 extern struct address_space *maybe_new_address_space (void);
300
301 /* Returns the integer address space id of ASPACE. */
302 extern int address_space_num (struct address_space *aspace);
303
304 /* Update all program spaces matching to address spaces. The user may
305 have created several program spaces, and loaded executables into
306 them before connecting to the target interface that will create the
307 inferiors. All that happens before GDB has a chance to know if the
308 inferiors will share an address space or not. Call this after
309 having connected to the target interface and having fetched the
310 target description, to fixup the program/address spaces
311 mappings. */
312 extern void update_address_spaces (void);
313
314 /* Reset saved solib data at the start of an solib event. This lets
315 us properly collect the data when calling solib_add, so it can then
316 later be printed. */
317 extern void clear_program_space_solib_cache (struct program_space *);
318
319 /* Keep a registry of per-pspace data-pointers required by other GDB
320 modules. */
321
322 DECLARE_REGISTRY (program_space);
323
324 /* Keep a registry of per-aspace data-pointers required by other GDB
325 modules. */
326
327 DECLARE_REGISTRY (address_space);
328
329 #endif
program_space::objfiles
struct objfile * objfiles
Definition: progspace.h:188
scoped_restore_current_program_space::scoped_restore_current_program_space
scoped_restore_current_program_space()
Definition: progspace.h:280
program_space::aspace
struct address_space * aspace
Definition: progspace.h:166
add_program_space
struct program_space * add_program_space(struct address_space *aspace)
Definition: progspace.c:113
set_current_program_space
void set_current_program_space(struct program_space *pspace)
Definition: progspace.c:190
program_space::symfile_object_file
struct objfile * symfile_object_file
Definition: progspace.h:184
so_list_ptr
struct so_list * so_list_ptr
Definition: progspace.h:38
address_space_num
int address_space_num(struct address_space *aspace)
Definition: progspace.c:94
inferior
Definition: inferior.h:310
program_space::breakpoints_not_allowed
int breakpoints_not_allowed
Definition: progspace.h:180
so_list
Definition: solist.h:38
address_space::num
int num
Definition: progspace.h:218
char_ptr
char * char_ptr
Definition: gdb_vecs.h:25
program_space::num
int num
Definition: progspace.h:143
update_address_spaces
void update_address_spaces(void)
Definition: progspace.c:376
address_space::REGISTRY_FIELDS
REGISTRY_FIELDS
Definition: progspace.h:221
current_program_space
struct program_space * current_program_space
Definition: progspace.c:35
target_ops
Definition: target.h:412
program_space::target_sections
struct target_section_table target_sections
Definition: progspace.h:192
program_space::so_list
struct so_list * so_list
Definition: progspace.h:196
program_space_empty_p
int program_space_empty_p(struct program_space *pspace)
Definition: progspace.c:206
clear_program_space_solib_cache
void clear_program_space_solib_cache(struct program_space *)
Definition: progspace.c:411
scoped_restore_current_program_space::~scoped_restore_current_program_space
~scoped_restore_current_program_space()
Definition: progspace.h:284
program_space::REGISTRY_FIELDS
REGISTRY_FIELDS
Definition: progspace.h:210
DEF_VEC_P
DEF_VEC_P(so_list_ptr)
target_section_table
Definition: target.h:2332
DECLARE_REGISTRY
DECLARE_REGISTRY(program_space)
program_space::VEC
VEC(so_list_ptr) *added_solibs
scoped_restore_current_program_space::DISABLE_COPY_AND_ASSIGN
DISABLE_COPY_AND_ASSIGN(scoped_restore_current_program_space)
program_space::solib_add_generation
unsigned solib_add_generation
Definition: progspace.h:199
new_address_space
struct address_space * new_address_space(void)
Definition: progspace.c:57
objfile
Definition: objfiles.h:286
program_space::ebfd
bfd * ebfd
Definition: progspace.h:149
program_space::ebfd_mtime
long ebfd_mtime
Definition: progspace.h:151
scoped_restore_current_program_space::m_saved_pspace
program_space * m_saved_pspace
Definition: progspace.h:290
address_space
Definition: progspace.h:216
program_space::executing_startup
int executing_startup
Definition: progspace.h:176
scoped_restore_current_program_space
Definition: progspace.h:277
program_space::pspace_exec_filename
char * pspace_exec_filename
Definition: progspace.h:155
gdb_vecs.h
target.h
number_of_program_spaces
int number_of_program_spaces(void)
Definition: progspace.c:353
maybe_new_address_space
struct address_space * maybe_new_address_space(void)
Definition: progspace.c:73
program_spaces
struct program_space * program_spaces
Definition: progspace.c:32
clone_program_space
struct program_space * clone_program_space(struct program_space *dest, struct program_space *src)
Definition: progspace.c:170
delete_program_space
void delete_program_space(struct program_space *pspace)
Definition: progspace.c:218
program_space::next
struct program_space * next
Definition: progspace.h:140
registry.h
program_space
Definition: progspace.h:137
vec.h