diff options
Diffstat (limited to 'gdb/progspace.h')
| -rw-r--r-- | gdb/progspace.h | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/gdb/progspace.h b/gdb/progspace.h new file mode 100644 index 0000000..2a0d1d2 --- /dev/null +++ b/gdb/progspace.h @@ -0,0 +1,283 @@ +/* Program and address space management, for GDB, the GNU debugger. + + Copyright (C) 2009 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; + + /* 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 (¤t_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); + +/* 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 |