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- /* Program and address space management, for GDB, the GNU debugger.
- Copyright (C) 2009-2022 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 "gdb_bfd.h"
- #include "gdbsupport/gdb_vecs.h"
- #include "registry.h"
- #include "solist.h"
- #include "gdbsupport/next-iterator.h"
- #include "gdbsupport/safe-iterator.h"
- #include <list>
- #include <vector>
- struct target_ops;
- struct bfd;
- struct objfile;
- struct inferior;
- struct exec;
- struct address_space;
- struct program_space_data;
- struct address_space_data;
- struct so_list;
- typedef std::list<std::shared_ptr<objfile>> objfile_list;
- /* An iterator that wraps an iterator over std::shared_ptr<objfile>,
- and dereferences the returned object. This is useful for iterating
- over a list of shared pointers and returning raw pointers -- which
- helped avoid touching a lot of code when changing how objfiles are
- managed. */
- class unwrapping_objfile_iterator
- {
- public:
- typedef unwrapping_objfile_iterator self_type;
- typedef typename ::objfile *value_type;
- typedef typename ::objfile &reference;
- typedef typename ::objfile **pointer;
- typedef typename objfile_list::iterator::iterator_category iterator_category;
- typedef typename objfile_list::iterator::difference_type difference_type;
- unwrapping_objfile_iterator (objfile_list::iterator iter)
- : m_iter (std::move (iter))
- {
- }
- objfile *operator* () const
- {
- return m_iter->get ();
- }
- unwrapping_objfile_iterator operator++ ()
- {
- ++m_iter;
- return *this;
- }
- bool operator!= (const unwrapping_objfile_iterator &other) const
- {
- return m_iter != other.m_iter;
- }
- private:
- /* The underlying iterator. */
- objfile_list::iterator m_iter;
- };
- /* A range that returns unwrapping_objfile_iterators. */
- using unwrapping_objfile_range = iterator_range<unwrapping_objfile_iterator>;
- /* 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
- {
- /* Constructs a new empty program space, binds it to ASPACE, and
- adds it to the program space list. */
- explicit program_space (address_space *aspace);
- /* Releases a program space, and all its contents (shared libraries,
- objfiles, and any other references to the program space in other
- modules). It is an internal error to call this when the program
- space is the current program space, since there should always be
- a program space. */
- ~program_space ();
- using objfiles_range = unwrapping_objfile_range;
- /* Return an iterable object that can be used to iterate over all
- objfiles. The basic use is in a foreach, like:
- for (objfile *objf : pspace->objfiles ()) { ... } */
- objfiles_range objfiles ()
- {
- return objfiles_range
- (unwrapping_objfile_iterator (objfiles_list.begin ()),
- unwrapping_objfile_iterator (objfiles_list.end ()));
- }
- using objfiles_safe_range = basic_safe_range<objfiles_range>;
- /* An iterable object that can be used to iterate over all objfiles.
- The basic use is in a foreach, like:
- for (objfile *objf : pspace->objfiles_safe ()) { ... }
- This variant uses a basic_safe_iterator so that objfiles can be
- deleted during iteration. */
- objfiles_safe_range objfiles_safe ()
- {
- return objfiles_safe_range
- (objfiles_range
- (unwrapping_objfile_iterator (objfiles_list.begin ()),
- unwrapping_objfile_iterator (objfiles_list.end ())));
- }
- /* Add OBJFILE to the list of objfiles, putting it just before
- BEFORE. If BEFORE is nullptr, it will go at the end of the
- list. */
- void add_objfile (std::shared_ptr<objfile> &&objfile,
- struct objfile *before);
- /* Remove OBJFILE from the list of objfiles. */
- void remove_objfile (struct objfile *objfile);
- /* Return true if there is more than one object file loaded; false
- otherwise. */
- bool multi_objfile_p () const
- {
- return objfiles_list.size () > 1;
- }
- /* Free all the objfiles associated with this program space. */
- void free_all_objfiles ();
- /* Return a range adapter for iterating over all the solibs in this
- program space. Use it like:
- for (so_list *so : pspace->solibs ()) { ... } */
- so_list_range solibs () const
- { return so_list_range (this->so_list); }
- /* Close and clear exec_bfd. If we end up with no target sections
- to read memory from, this unpushes the exec_ops target. */
- void exec_close ();
- /* Return the exec BFD for this program space. */
- bfd *exec_bfd () const
- {
- return ebfd.get ();
- }
- /* Set the exec BFD for this program space to ABFD. */
- void set_exec_bfd (gdb_bfd_ref_ptr &&abfd)
- {
- ebfd = std::move (abfd);
- }
- /* Reset saved solib data at the start of an solib event. This lets
- us properly collect the data when calling solib_add, so it can then
- later be printed. */
- void clear_solib_cache ();
- /* Returns true iff there's no inferior bound to this program
- space. */
- bool empty ();
- /* Remove all target sections owned by OWNER. */
- void remove_target_sections (void *owner);
- /* Add the sections array defined by SECTIONS to the
- current set of target sections. */
- void add_target_sections (void *owner,
- const target_section_table §ions);
- /* Add the sections of OBJFILE to the current set of target
- sections. They are given OBJFILE as the "owner". */
- void add_target_sections (struct objfile *objfile);
- /* Clear all target sections from M_TARGET_SECTIONS table. */
- void clear_target_sections ()
- {
- m_target_sections.clear ();
- }
- /* Return a reference to the M_TARGET_SECTIONS table. */
- target_section_table &target_sections ()
- {
- return m_target_sections;
- }
- /* Unique ID number. */
- int num = 0;
- /* The main executable loaded into this program space. This is
- managed by the exec target. */
- /* The BFD handle for the main executable. */
- gdb_bfd_ref_ptr ebfd;
- /* The last-modified time, from when the exec was brought in. */
- long ebfd_mtime = 0;
- /* Similar to bfd_get_filename (exec_bfd) but in original form given
- by user, without symbolic links and pathname resolved. It is not
- NULL iff EBFD is not NULL. */
- gdb::unique_xmalloc_ptr<char> exec_filename;
- /* Binary file diddling handle for the core file. */
- gdb_bfd_ref_ptr cbfd;
- /* 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 = NULL;
- /* 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 = 0;
- /* True if no breakpoints should be inserted in this program
- space. */
- int breakpoints_not_allowed = 0;
- /* 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 = NULL;
- /* All known objfiles are kept in a linked list. */
- std::list<std::shared_ptr<objfile>> objfiles_list;
- /* List of shared objects mapped into this space. Managed by
- solib.c. */
- struct so_list *so_list = NULL;
- /* Number of calls to solib_add. */
- unsigned int solib_add_generation = 0;
- /* When an solib is added, it is also added to this vector. This
- is so we can properly report solib changes to the user. */
- std::vector<struct so_list *> added_solibs;
- /* When an solib is removed, its name is added to this vector.
- This is so we can properly report solib changes to the user. */
- std::vector<std::string> deleted_solibs;
- /* Per pspace data-pointers required by other GDB modules. */
- REGISTRY_FIELDS {};
- private:
- /* The set of target sections matching the sections mapped into
- this program space. Managed by both exec_ops and solib.c. */
- target_section_table m_target_sections;
- };
- /* An address space. It is used for comparing if
- pspaces/inferior/threads see the same address space and for
- associating caches to each address space. */
- struct address_space
- {
- int num;
- /* Per aspace data-pointers required by other GDB modules. */
- REGISTRY_FIELDS;
- };
- /* The list of all program spaces. There's always at least one. */
- extern std::vector<struct program_space *>program_spaces;
- /* The current program space. This is always non-null. */
- extern struct program_space *current_program_space;
- /* 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);
- /* 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);
- /* Save/restore the current program space. */
- class scoped_restore_current_program_space
- {
- public:
- scoped_restore_current_program_space ()
- : m_saved_pspace (current_program_space)
- {}
- ~scoped_restore_current_program_space ()
- { set_current_program_space (m_saved_pspace); }
- DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space);
- private:
- program_space *m_saved_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);
- /* Keep a registry of per-pspace data-pointers required by other GDB
- modules. */
- DECLARE_REGISTRY (program_space);
- /* Keep a registry of per-aspace data-pointers required by other GDB
- modules. */
- DECLARE_REGISTRY (address_space);
- #endif
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