[deliverable/binutils-gdb.git] / gdb / progspace.h

/* Program and address space management, for GDB, the GNU debugger.

   Copyright (C) 2009, 2010 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */


#ifndef PROGSPACE_H
#define PROGSPACE_H

#include "target.h"
#include "vec.h"

struct target_ops;
struct bfd;
struct objfile;
struct inferior;
struct exec;
struct address_space;
struct program_space_data;

/* A program space represents a symbolic view of an address space.
   Roughly speaking, it holds all the data associated with a
   non-running-yet program (main executable, main symbols), and when
   an inferior is running and is bound to it, includes the list of its
   mapped in shared libraries.

   In the traditional debugging scenario, there's a 1-1 correspondence
   among program spaces, inferiors and address spaces, like so:

     pspace1 (prog1) <--> inf1(pid1) <--> aspace1

   In the case of debugging more than one traditional unix process or
   program, we still have:

     |-----------------+------------+---------|
     | pspace1 (prog1) | inf1(pid1) | aspace1 |
     |----------------------------------------|
     | pspace2 (prog1) | no inf yet | aspace2 |
     |-----------------+------------+---------|
     | pspace3 (prog2) | inf2(pid2) | aspace3 |
     |-----------------+------------+---------|

   In the former example, if inf1 forks (and GDB stays attached to
   both processes), the new child will have its own program and
   address spaces.  Like so:

     |-----------------+------------+---------|
     | pspace1 (prog1) | inf1(pid1) | aspace1 |
     |-----------------+------------+---------|
     | pspace2 (prog1) | inf2(pid2) | aspace2 |
     |-----------------+------------+---------|

   However, had inf1 from the latter case vforked instead, it would
   share the program and address spaces with its parent, until it
   execs or exits, like so:

     |-----------------+------------+---------|
     | pspace1 (prog1) | inf1(pid1) | aspace1 |
     |                 | inf2(pid2) |         |
     |-----------------+------------+---------|

   When the vfork child execs, it is finally given new program and
   address spaces.

     |-----------------+------------+---------|
     | pspace1 (prog1) | inf1(pid1) | aspace1 |
     |-----------------+------------+---------|
     | pspace2 (prog1) | inf2(pid2) | aspace2 |
     |-----------------+------------+---------|

   There are targets where the OS (if any) doesn't provide memory
   management or VM protection, where all inferiors share the same
   address space --- e.g. uClinux.  GDB models this by having all
   inferiors share the same address space, but, giving each its own
   program space, like so:

     |-----------------+------------+---------|
     | pspace1 (prog1) | inf1(pid1) |         |
     |-----------------+------------+         |
     | pspace2 (prog1) | inf2(pid2) | aspace1 |
     |-----------------+------------+         |
     | pspace3 (prog2) | inf3(pid3) |         |
     |-----------------+------------+---------|

   The address space sharing matters for run control and breakpoints
   management.  E.g., did we just hit a known breakpoint that we need
   to step over?  Is this breakpoint a duplicate of this other one, or
   do I need to insert a trap?

   Then, there are targets where all symbols look the same for all
   inferiors, although each has its own address space, as e.g.,
   Ericsson DICOS.  In such case, the model is:

     |---------+------------+---------|
     |         | inf1(pid1) | aspace1 |
     |         +------------+---------|
     | pspace  | inf2(pid2) | aspace2 |
     |         +------------+---------|
     |         | inf3(pid3) | aspace3 |
     |---------+------------+---------|

   Note however, that the DICOS debug API takes care of making GDB
   believe that breakpoints are "global".  That is, although each
   process does have its own private copy of data symbols (just like a
   bunch of forks), to the breakpoints module, all processes share a
   single address space, so all breakpoints set at the same address
   are duplicates of each other, even breakpoints set in the data
   space (e.g., call dummy breakpoints placed on stack).  This allows
   a simplification in the spaces implementation: we avoid caring for
   a many-many links between address and program spaces.  Either
   there's a single address space bound to the program space
   (traditional unix/uClinux), or, in the DICOS case, the address
   space bound to the program space is mostly ignored.  */

/* The program space structure.  */

struct program_space
  {
    /* Pointer to next in linked list.  */
    struct program_space *next;

    /* Unique ID number.  */
    int num;

    /* The main executable loaded into this program space.  This is
       managed by the exec target.  */

    /* The BFD handle for the main executable.  */
    bfd *ebfd;
    /* The last-modified time, from when the exec was brought in.  */
    long ebfd_mtime;

    /* The address space attached to this program space.  More than one
       program space may be bound to the same address space.  In the
       traditional unix-like debugging scenario, this will usually
       match the address space bound to the inferior, and is mostly
       used by the breakpoints module for address matches.  If the
       target shares a program space for all inferiors and breakpoints
       are global, then this field is ignored (we don't currently
       support inferiors sharing a program space if the target doesn't
       make breakpoints global).  */
    struct address_space *aspace;

    /* True if this program space's section offsets don't yet represent
       the final offsets of the "live" address space (that is, the
       section addresses still require the relocation offsets to be
       applied, and hence we can't trust the section addresses for
       anything that pokes at live memory).  E.g., for qOffsets
       targets, or for PIE executables, until we connect and ask the
       target for the final relocation offsets, the symbols we've used
       to set breakpoints point at the wrong addresses.  */
    int executing_startup;

    /* True if no breakpoints should be inserted in this program
       space.  */
    int breakpoints_not_allowed;

    /* The object file that the main symbol table was loaded from
       (e.g. the argument to the "symbol-file" or "file" command).  */
    struct objfile *symfile_object_file;

    /* All known objfiles are kept in a linked list.  This points to
       the head of this list. */
    struct objfile *objfiles;

    /* The set of target sections matching the sections mapped into
       this program space.  Managed by both exec_ops and solib.c.  */
    struct target_section_table target_sections;

    /* List of shared objects mapped into this space.  Managed by
       solib.c.  */
    struct so_list *so_list;

    /* Per pspace data-pointers required by other GDB modules.  */
    void **data;
    unsigned num_data;
  };

/* The object file that the main symbol table was loaded from (e.g. the
   argument to the "symbol-file" or "file" command).  */

#define symfile_objfile current_program_space->symfile_object_file

/* All known objfiles are kept in a linked list.  This points to the
   root of this list. */
#define object_files current_program_space->objfiles

/* The set of target sections matching the sections mapped into the
   current program space.  */
#define current_target_sections (&current_program_space->target_sections)

/* The list of all program spaces.  There's always at least one.  */
extern struct program_space *program_spaces;

/* The current program space.  This is always non-null.  */
extern struct program_space *current_program_space;

#define ALL_PSPACES(pspace) \
  for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next)

/* Add a new empty program space, and assign ASPACE to it.  Returns the
   pointer to the new object.  */
extern struct program_space *add_program_space (struct address_space *aspace);

/* Release PSPACE and removes it from the pspace list.  */
extern void remove_program_space (struct program_space *pspace);

/* Returns the number of program spaces listed.  */
extern int number_of_program_spaces (void);

/* Copies program space SRC to DEST.  Copies the main executable file,
   and the main symbol file.  Returns DEST.  */
extern struct program_space *clone_program_space (struct program_space *dest,
						struct program_space *src);

/* Save the current program space so that it may be restored by a later
   call to do_cleanups.  Returns the struct cleanup pointer needed for
   later doing the cleanup.  */
extern struct cleanup *save_current_program_space (void);

/* Sets PSPACE as the current program space.  This is usually used
   instead of set_current_space_and_thread when the current
   thread/inferior is not important for the operations that follow.
   E.g., when accessing the raw symbol tables.  If memory access is
   required, then you should use switch_to_program_space_and_thread.
   Otherwise, it is the caller's responsibility to make sure that the
   currently selected inferior/thread matches the selected program
   space.  */
extern void set_current_program_space (struct program_space *pspace);

/* Saves the current thread (may be null), frame and program space in
   the current cleanup chain.  */
extern struct cleanup *save_current_space_and_thread (void);

/* Switches full context to program space PSPACE.  Switches to the
   first thread found bound to PSPACE.  */
extern void switch_to_program_space_and_thread (struct program_space *pspace);

/* Create a new address space object, and add it to the list.  */
extern struct address_space *new_address_space (void);

/* Maybe create a new address space object, and add it to the list, or
   return a pointer to an existing address space, in case inferiors
   share an address space.  */
extern struct address_space *maybe_new_address_space (void);

/* Returns the integer address space id of ASPACE.  */
extern int address_space_num (struct address_space *aspace);

/* Update all program spaces matching to address spaces.  The user may
   have created several program spaces, and loaded executables into
   them before connecting to the target interface that will create the
   inferiors.  All that happens before GDB has a chance to know if the
   inferiors will share an address space or not.  Call this after
   having connected to the target interface and having fetched the
   target description, to fixup the program/address spaces
   mappings.  */
extern void update_address_spaces (void);

/* Prune away automatically added program spaces that aren't required
   anymore.  */
extern void prune_program_spaces (void);

/* Keep a registry of per-pspace data-pointers required by other GDB
   modules.  */

extern const struct program_space_data *register_program_space_data (void);
extern const struct program_space_data *register_program_space_data_with_cleanup
  (void (*cleanup) (struct program_space *, void *));
extern void clear_program_space_data (struct program_space *pspace);
extern void set_program_space_data (struct program_space *pspace,
			      const struct program_space_data *data, void *value);
extern void *program_space_data (struct program_space *pspace,
			   const struct program_space_data *data);

#endif
Commit	Line	Data
6c95b8df PA	1	/* Program and address space management, for GDB, the GNU debugger.
6c95b8df PA	2
4c38e0a4	3	Copyright (C) 2009, 2010 Free Software Foundation, Inc.
6c95b8df PA	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
	27	struct target_ops;
	28	struct bfd;
	29	struct objfile;
	30	struct inferior;
	31	struct exec;
	32	struct address_space;
	33	struct program_space_data;
	34
	35	/* A program space represents a symbolic view of an address space.
	36	Roughly speaking, it holds all the data associated with a
	37	non-running-yet program (main executable, main symbols), and when
	38	an inferior is running and is bound to it, includes the list of its
	39	mapped in shared libraries.
	40
	41	In the traditional debugging scenario, there's a 1-1 correspondence
	42	among program spaces, inferiors and address spaces, like so:
	43
	44	pspace1 (prog1) <--> inf1(pid1) <--> aspace1
	45
	46	In the case of debugging more than one traditional unix process or
	47	program, we still have:
	48
	49	\|-----------------+------------+---------\|
	50	\| pspace1 (prog1) \| inf1(pid1) \| aspace1 \|
	51	\|----------------------------------------\|
	52	\| pspace2 (prog1) \| no inf yet \| aspace2 \|
	53	\|-----------------+------------+---------\|
	54	\| pspace3 (prog2) \| inf2(pid2) \| aspace3 \|
	55	\|-----------------+------------+---------\|
	56
	57	In the former example, if inf1 forks (and GDB stays attached to
	58	both processes), the new child will have its own program and
	59	address spaces. Like so:
	60
	61	\|-----------------+------------+---------\|
	62	\| pspace1 (prog1) \| inf1(pid1) \| aspace1 \|
	63	\|-----------------+------------+---------\|
	64	\| pspace2 (prog1) \| inf2(pid2) \| aspace2 \|
	65	\|-----------------+------------+---------\|
	66
	67	However, had inf1 from the latter case vforked instead, it would
68	share the program and address spaces with its parent, until it
69	execs or exits, like so:
70
71	\|-----------------+------------+---------\|
72	\| pspace1 (prog1) \| inf1(pid1) \| aspace1 \|
73	\| \| inf2(pid2) \| \|
74	\|-----------------+------------+---------\|
75
76	When the vfork child execs, it is finally given new program and
77	address spaces.
78
79	\|-----------------+------------+---------\|
80	\| pspace1 (prog1) \| inf1(pid1) \| aspace1 \|
81	\|-----------------+------------+---------\|
82	\| pspace2 (prog1) \| inf2(pid2) \| aspace2 \|
83	\|-----------------+------------+---------\|
84
85	There are targets where the OS (if any) doesn't provide memory
86	management or VM protection, where all inferiors share the same
87	address space --- e.g. uClinux. GDB models this by having all
88	inferiors share the same address space, but, giving each its own
89	program space, like so:
90
91	\|-----------------+------------+---------\|
92	\| pspace1 (prog1) \| inf1(pid1) \| \|
93	\|-----------------+------------+ \|
94	\| pspace2 (prog1) \| inf2(pid2) \| aspace1 \|
95	\|-----------------+------------+ \|
96	\| pspace3 (prog2) \| inf3(pid3) \| \|
97	\|-----------------+------------+---------\|
98
99	The address space sharing matters for run control and breakpoints
100	management. E.g., did we just hit a known breakpoint that we need
101	to step over? Is this breakpoint a duplicate of this other one, or
102	do I need to insert a trap?
103
104	Then, there are targets where all symbols look the same for all
105	inferiors, although each has its own address space, as e.g.,
106	Ericsson DICOS. In such case, the model is:
107
108	\|---------+------------+---------\|
109	\| \| inf1(pid1) \| aspace1 \|
110	\| +------------+---------\|
111	\| pspace \| inf2(pid2) \| aspace2 \|
112	\| +------------+---------\|
113	\| \| inf3(pid3) \| aspace3 \|
114	\|---------+------------+---------\|
115
116	Note however, that the DICOS debug API takes care of making GDB
117	believe that breakpoints are "global". That is, although each
118	process does have its own private copy of data symbols (just like a
119	bunch of forks), to the breakpoints module, all processes share a
120	single address space, so all breakpoints set at the same address
121	are duplicates of each other, even breakpoints set in the data
122	space (e.g., call dummy breakpoints placed on stack). This allows
123	a simplification in the spaces implementation: we avoid caring for
124	a many-many links between address and program spaces. Either
125	there's a single address space bound to the program space
126	(traditional unix/uClinux), or, in the DICOS case, the address
127	space bound to the program space is mostly ignored. */
128
129	/* The program space structure. */
130
131	struct program_space
132	{
133	/* Pointer to next in linked list. */
134	struct program_space *next;
135
136	/* Unique ID number. */
137	int num;
138
139	/* The main executable loaded into this program space. This is
140	managed by the exec target. */
141
142	/* The BFD handle for the main executable. */
143	bfd *ebfd;
144	/* The last-modified time, from when the exec was brought in. */
145	long ebfd_mtime;
146
147	/* The address space attached to this program space. More than one
148	program space may be bound to the same address space. In the
149	traditional unix-like debugging scenario, this will usually
150	match the address space bound to the inferior, and is mostly
151	used by the breakpoints module for address matches. If the
152	target shares a program space for all inferiors and breakpoints
153	are global, then this field is ignored (we don't currently
154	support inferiors sharing a program space if the target doesn't
155	make breakpoints global). */
156	struct address_space *aspace;
157
158	/* True if this program space's section offsets don't yet represent
159	the final offsets of the "live" address space (that is, the
160	section addresses still require the relocation offsets to be
161	applied, and hence we can't trust the section addresses for
162	anything that pokes at live memory). E.g., for qOffsets
163	targets, or for PIE executables, until we connect and ask the
164	target for the final relocation offsets, the symbols we've used
165	to set breakpoints point at the wrong addresses. */
166	int executing_startup;
167
56710373 PA	168	/* True if no breakpoints should be inserted in this program
	169	space. */
	170	int breakpoints_not_allowed;
	171
6c95b8df PA	172	/* The object file that the main symbol table was loaded from
	173	(e.g. the argument to the "symbol-file" or "file" command). */
	174	struct objfile *symfile_object_file;
	175
	176	/* All known objfiles are kept in a linked list. This points to
	177	the head of this list. */
	178	struct objfile *objfiles;
	179
	180	/* The set of target sections matching the sections mapped into
	181	this program space. Managed by both exec_ops and solib.c. */
	182	struct target_section_table target_sections;
	183
	184	/* List of shared objects mapped into this space. Managed by
	185	solib.c. */
	186	struct so_list *so_list;
	187
	188	/* Per pspace data-pointers required by other GDB modules. */
	189	void **data;
	190	unsigned num_data;
	191	};
	192
	193	/* The object file that the main symbol table was loaded from (e.g. the
	194	argument to the "symbol-file" or "file" command). */
	195
	196	#define symfile_objfile current_program_space->symfile_object_file
	197
	198	/* All known objfiles are kept in a linked list. This points to the
	199	root of this list. */
	200	#define object_files current_program_space->objfiles
	201
	202	/* The set of target sections matching the sections mapped into the
	203	current program space. */
	204	#define current_target_sections (&current_program_space->target_sections)
	205
	206	/* The list of all program spaces. There's always at least one. */
	207	extern struct program_space *program_spaces;
	208
	209	/* The current program space. This is always non-null. */
	210	extern struct program_space *current_program_space;
	211
	212	#define ALL_PSPACES(pspace) \
	213	for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next)
	214
	215	/* Add a new empty program space, and assign ASPACE to it. Returns the
	216	pointer to the new object. */
	217	extern struct program_space add_program_space (struct address_space aspace);
	218
	219	/* Release PSPACE and removes it from the pspace list. */
	220	extern void remove_program_space (struct program_space *pspace);
	221
	222	/* Returns the number of program spaces listed. */
	223	extern int number_of_program_spaces (void);
	224
	225	/* Copies program space SRC to DEST. Copies the main executable file,
	226	and the main symbol file. Returns DEST. */
	227	extern struct program_space clone_program_space (struct program_space dest,
	228	struct program_space *src);
	229
	230	/* Save the current program space so that it may be restored by a later
	231	call to do_cleanups. Returns the struct cleanup pointer needed for
	232	later doing the cleanup. */
	233	extern struct cleanup *save_current_program_space (void);
	234
	235	/* Sets PSPACE as the current program space. This is usually used
236	instead of set_current_space_and_thread when the current
237	thread/inferior is not important for the operations that follow.
238	E.g., when accessing the raw symbol tables. If memory access is
239	required, then you should use switch_to_program_space_and_thread.
240	Otherwise, it is the caller's responsibility to make sure that the
241	currently selected inferior/thread matches the selected program
242	space. */
243	extern void set_current_program_space (struct program_space *pspace);
244
245	/* Saves the current thread (may be null), frame and program space in
246	the current cleanup chain. */
247	extern struct cleanup *save_current_space_and_thread (void);
248
249	/* Switches full context to program space PSPACE. Switches to the
250	first thread found bound to PSPACE. */
251	extern void switch_to_program_space_and_thread (struct program_space *pspace);
252
253	/* Create a new address space object, and add it to the list. */
254	extern struct address_space *new_address_space (void);
255
256	/* Maybe create a new address space object, and add it to the list, or
257	return a pointer to an existing address space, in case inferiors
258	share an address space. */
259	extern struct address_space *maybe_new_address_space (void);
260
c0694254 PA	261	/* Returns the integer address space id of ASPACE. */
	262	extern int address_space_num (struct address_space *aspace);
	263
6c95b8df PA	264	/* Update all program spaces matching to address spaces. The user may
	265	have created several program spaces, and loaded executables into
	266	them before connecting to the target interface that will create the
	267	inferiors. All that happens before GDB has a chance to know if the
	268	inferiors will share an address space or not. Call this after
	269	having connected to the target interface and having fetched the
	270	target description, to fixup the program/address spaces
	271	mappings. */
	272	extern void update_address_spaces (void);
	273
	274	/* Prune away automatically added program spaces that aren't required
	275	anymore. */
	276	extern void prune_program_spaces (void);
	277
	278	/* Keep a registry of per-pspace data-pointers required by other GDB
	279	modules. */
	280
	281	extern const struct program_space_data *register_program_space_data (void);
	282	extern const struct program_space_data *register_program_space_data_with_cleanup
	283	(void (cleanup) (struct program_space , void *));
	284	extern void clear_program_space_data (struct program_space *pspace);
	285	extern void set_program_space_data (struct program_space *pspace,
	286	const struct program_space_data data, void value);
	287	extern void program_space_data (struct program_space pspace,
	288	const struct program_space_data *data);
	289
	290	#endif