From 74daa597e743462d272522512efbe3f65659c4c0 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Tue, 3 Oct 2023 22:20:21 -0400 Subject: [PATCH] gdb: add all_objfiles_removed observer The new_objfile observer is currently used to indicate both when a new objfile is added to program space (when passed non-nullptr) and when all objfiles of a program space were just removed (when passed nullptr). I think this is confusing (and Andrew apparently thinks so too [1]). Add a new "all_objfiles_removed" observer to remove the second role from "new_objfile". Some existing users of new_objfile do nothing if the passed objfile is nullptr. For them, we can simply drop the nullptr check. For others, add a new all_objfiles_removed callback, and refactor things a bit to keep the existing behavior as much as possible. Some callbacks relied on current_program_space, and following the refactoring now use either objfile->pspace or the pspace passed to all_objfiles_removed. I think this should be relatively safe, and in general a step in the right direction. On the notify side, I found only one call site to change from new_objfile to all_objfiles_removed, in clear_symtab_users. It is not entirely clear to me that this is entirely correct. clear_symtab_users appears to be called in spots that don't remove all objfiles (functions finish_new_objfile, remove_symbol_file_command, reread_symbols, do_module_cleanups). But I think that this patch at least makes the current code clearer. [1] https://gitlab.com/gnutools/binutils-gdb/-/commit/a0a031bce0527b1521788b5dad640e7883b3a252 Change-Id: Icb648f72862e056267f30f44dd439bd4ec766f13 Approved-By: Tom Tromey --- gdb/ada-lang.c | 6 ++++-- gdb/ada-tasks.c | 41 ++++++++++++++++++---------------------- gdb/agent.c | 2 +- gdb/aix-thread.c | 7 +++---- gdb/arm-tdep.c | 2 +- gdb/auto-load.c | 29 ++++++++-------------------- gdb/auxv.c | 22 +++++++-------------- gdb/linux-thread-db.c | 5 ++--- gdb/observable.c | 1 + gdb/observable.h | 7 ++++--- gdb/python/py-inferior.c | 30 ++++++++++++++++------------- gdb/remote.c | 18 +++++++++++++----- gdb/sol-thread.c | 3 +-- gdb/symfile.c | 2 +- gdb/symtab.c | 19 +++++++++++++------ gdb/tui/tui-hooks.c | 13 +++++++++++-- 16 files changed, 105 insertions(+), 102 deletions(-) diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c index 4dc40558064..a37e5637534 100644 --- a/gdb/ada-lang.c +++ b/gdb/ada-lang.c @@ -13884,7 +13884,7 @@ static struct cmd_list_element *show_ada_list; static void ada_new_objfile_observer (struct objfile *objfile) { - ada_clear_symbol_cache (current_program_space); + ada_clear_symbol_cache (objfile->pspace); } /* This module's 'free_objfile' observer. */ @@ -13892,7 +13892,7 @@ ada_new_objfile_observer (struct objfile *objfile) static void ada_free_objfile_observer (struct objfile *objfile) { - ada_clear_symbol_cache (current_program_space); + ada_clear_symbol_cache (objfile->pspace); } /* Charsets known to GNAT. */ @@ -14025,6 +14025,8 @@ DWARF attribute."), /* The ada-lang observers. */ gdb::observers::new_objfile.attach (ada_new_objfile_observer, "ada-lang"); + gdb::observers::all_objfiles_removed.attach (ada_clear_symbol_cache, + "ada-lang"); gdb::observers::free_objfile.attach (ada_free_objfile_observer, "ada-lang"); gdb::observers::inferior_exit.attach (ada_inferior_exit, "ada-lang"); diff --git a/gdb/ada-tasks.c b/gdb/ada-tasks.c index 14b0bf11c2a..1de6b0fc930 100644 --- a/gdb/ada-tasks.c +++ b/gdb/ada-tasks.c @@ -1469,38 +1469,31 @@ ada_tasks_normal_stop_observer (struct bpstat *unused_args, int unused_args2) ada_task_list_changed (current_inferior ()); } -/* A routine to be called when the objfiles have changed. */ +/* Clear data associated to PSPACE and all inferiors using that program + space. */ static void -ada_tasks_new_objfile_observer (struct objfile *objfile) +ada_tasks_clear_pspace_data (program_space *pspace) { - /* Invalidate the relevant data in our program-space data. */ - - if (objfile == NULL) - { - /* All objfiles are being cleared, so we should clear all - our caches for all program spaces. */ - for (struct program_space *pspace : program_spaces) - ada_tasks_invalidate_pspace_data (pspace); - } - else - { - /* The associated program-space data might have changed after - this objfile was added. Invalidate all cached data. */ - ada_tasks_invalidate_pspace_data (objfile->pspace); - } + /* The associated program-space data might have changed after + this objfile was added. Invalidate all cached data. */ + ada_tasks_invalidate_pspace_data (pspace); /* Invalidate the per-inferior cache for all inferiors using - this objfile (or, in other words, for all inferiors who have - the same program-space as the objfile's program space). - If all objfiles are being cleared (OBJFILE is NULL), then - clear the caches for all inferiors. */ - + this program space. */ for (inferior *inf : all_inferiors ()) - if (objfile == NULL || inf->pspace == objfile->pspace) + if (inf->pspace == pspace) ada_tasks_invalidate_inferior_data (inf); } +/* Called when a new objfile was added. */ + +static void +ada_tasks_new_objfile_observer (objfile *objfile) +{ + ada_tasks_clear_pspace_data (objfile->pspace); +} + /* The qcs command line flags for the "task apply" commands. Keep this in sync with the "frame apply" commands. */ @@ -1667,6 +1660,8 @@ _initialize_tasks () "ada-tasks"); gdb::observers::new_objfile.attach (ada_tasks_new_objfile_observer, "ada-tasks"); + gdb::observers::all_objfiles_removed.attach (ada_tasks_clear_pspace_data, + "ada-tasks"); static struct cmd_list_element *task_cmd_list; static struct cmd_list_element *task_apply_list; diff --git a/gdb/agent.c b/gdb/agent.c index e2ad3b582fa..d7e48589ab9 100644 --- a/gdb/agent.c +++ b/gdb/agent.c @@ -65,7 +65,7 @@ set_can_use_agent (const char *args, int from_tty, struct cmd_list_element *c) static void agent_new_objfile (struct objfile *objfile) { - if (objfile == NULL || agent_loaded_p ()) + if (agent_loaded_p ()) return; if (can_use_agent == can_use_agent_off) diff --git a/gdb/aix-thread.c b/gdb/aix-thread.c index 1f7b3c511cf..2077491d3cf 100644 --- a/gdb/aix-thread.c +++ b/gdb/aix-thread.c @@ -1109,14 +1109,13 @@ pd_disable (inferior *inf) /* new_objfile observer callback. - If OBJFILE is non-null, check whether a threaded application is - being debugged, and if so, prepare for thread debugging. */ + Check whether a threaded application is being debugged, and if so, prepare + for thread debugging. */ static void new_objfile (struct objfile *objfile) { - if (objfile) - pd_enable (current_inferior ()); + pd_enable (current_inferior ()); } /* Attach to process specified by ARGS. */ diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 24952840e08..7e069d18770 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -2543,7 +2543,7 @@ arm_exidx_new_objfile (struct objfile *objfile) LONGEST i; /* If we've already touched this file, do nothing. */ - if (!objfile || arm_exidx_data_key.get (objfile->obfd.get ()) != NULL) + if (arm_exidx_data_key.get (objfile->obfd.get ()) != nullptr) return; /* Read contents of exception table and index. */ diff --git a/gdb/auto-load.c b/gdb/auto-load.c index 37a44cc2eaa..8bbe6696dcc 100644 --- a/gdb/auto-load.c +++ b/gdb/auto-load.c @@ -1138,7 +1138,11 @@ auto_load_section_scripts (struct objfile *objfile, const char *section_name) } } -/* Load any auto-loaded scripts for OBJFILE. */ +/* Load any auto-loaded scripts for OBJFILE. + + Two flavors of auto-loaded scripts are supported. + 1) based on the path to the objfile + 2) from .debug_gdb_scripts section */ void load_auto_scripts_for_objfile (struct objfile *objfile) @@ -1160,25 +1164,6 @@ load_auto_scripts_for_objfile (struct objfile *objfile) auto_load_section_scripts (objfile, AUTO_SECTION_NAME); } -/* This is a new_objfile observer callback to auto-load scripts. - - Two flavors of auto-loaded scripts are supported. - 1) based on the path to the objfile - 2) from .debug_gdb_scripts section */ - -static void -auto_load_new_objfile (struct objfile *objfile) -{ - if (!objfile) - { - /* OBJFILE is NULL when loading a new "main" symbol-file. */ - clear_section_scripts (current_program_space); - return; - } - - load_auto_scripts_for_objfile (objfile); -} - /* Collect scripts to be printed in a vec. */ struct collect_matching_scripts_data @@ -1531,9 +1516,11 @@ _initialize_auto_load () python_name_help, guile_name_help; const char *suffix; - gdb::observers::new_objfile.attach (auto_load_new_objfile, + gdb::observers::new_objfile.attach (load_auto_scripts_for_objfile, auto_load_new_objfile_observer_token, "auto-load"); + gdb::observers::all_objfiles_removed.attach (clear_section_scripts, + "auto-load"); add_setshow_boolean_cmd ("gdb-scripts", class_support, &auto_load_gdb_scripts, _("\ Enable or disable auto-loading of canned sequences of commands scripts."), _("\ diff --git a/gdb/auxv.c b/gdb/auxv.c index cfb44ffa0bb..7e3efc54e4b 100644 --- a/gdb/auxv.c +++ b/gdb/auxv.c @@ -344,23 +344,14 @@ invalidate_auxv_cache_inf (struct inferior *inf) auxv_inferior_data.clear (inf); } -/* Invalidate current inferior's auxv cache when all symbol table data is - cleared (indicated by OBJFILE being nullptr). */ +/* Invalidate the auxv cache for all inferiors using PSPACE. */ static void -auxv_new_objfile_observer (struct objfile *objfile) +auxv_all_objfiles_removed (program_space *pspace) { - if (objfile == nullptr) - { - /* When OBJFILE is nullptr, this indicates that all symbol files have - been unloaded from the current program space. Discard cached auxv - information from any inferior within the effected program space. */ - for (inferior *inf : all_inferiors ()) - { - if (inf->pspace == current_program_space) - invalidate_auxv_cache_inf (inf); - } - } + for (inferior *inf : all_inferiors ()) + if (inf->pspace == current_program_space) + invalidate_auxv_cache_inf (inf); } /* See auxv.h. */ @@ -624,5 +615,6 @@ This is information provided by the operating system at program startup.")); /* Observers used to invalidate the auxv cache when needed. */ gdb::observers::inferior_exit.attach (invalidate_auxv_cache_inf, "auxv"); gdb::observers::inferior_appeared.attach (invalidate_auxv_cache_inf, "auxv"); - gdb::observers::new_objfile.attach (auxv_new_objfile_observer, "auxv"); + gdb::observers::all_objfiles_removed.attach (auxv_all_objfiles_removed, + "auxv"); } diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c index 16c250c104d..cef78f599be 100644 --- a/gdb/linux-thread-db.c +++ b/gdb/linux-thread-db.c @@ -1278,13 +1278,12 @@ thread_db_new_objfile (struct objfile *objfile) /* This observer must always be called with inferior_ptid set correctly. */ - if (objfile != NULL - /* libpthread with separate debug info has its debug info file already + if (/* libpthread with separate debug info has its debug info file already loaded (and notified without successful thread_db initialization) the time gdb::observers::new_objfile.notify is called for the library itself. Static executables have their separate debug info loaded already before the inferior has started. */ - && objfile->separate_debug_objfile_backlink == NULL + objfile->separate_debug_objfile_backlink == NULL /* Only check for thread_db if we loaded libpthread, or if this is the main symbol file. We need to check OBJF_MAINLINE to handle the case of debugging diff --git a/gdb/observable.c b/gdb/observable.c index 93a842e911f..09613b2ddda 100644 --- a/gdb/observable.c +++ b/gdb/observable.c @@ -42,6 +42,7 @@ DEFINE_OBSERVABLE (inferior_forked); DEFINE_OBSERVABLE (solib_loaded); DEFINE_OBSERVABLE (solib_unloaded); DEFINE_OBSERVABLE (new_objfile); +DEFINE_OBSERVABLE (all_objfiles_removed); DEFINE_OBSERVABLE (free_objfile); DEFINE_OBSERVABLE (new_thread); DEFINE_OBSERVABLE (thread_exit); diff --git a/gdb/observable.h b/gdb/observable.h index d9fc5cbcc8b..5a2144030b3 100644 --- a/gdb/observable.h +++ b/gdb/observable.h @@ -107,11 +107,12 @@ extern observable solib_loaded; extern observable solib_unloaded; -/* The symbol file specified by OBJFILE has been loaded. Called - with OBJFILE equal to NULL to indicate previously loaded symbol - table data has now been invalidated. */ +/* The symbol file specified by OBJFILE has been loaded. */ extern observable new_objfile; +/* All objfiles from PSPACE were removed. */ +extern observable all_objfiles_removed; + /* The object file specified by OBJFILE is about to be freed. */ extern observable free_objfile; diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c index e7a9d822409..1f20b9acd11 100644 --- a/gdb/python/py-inferior.c +++ b/gdb/python/py-inferior.c @@ -190,20 +190,22 @@ python_new_objfile (struct objfile *objfile) if (!gdb_python_initialized) return; - gdbpy_enter enter_py (objfile != NULL - ? objfile->arch () - : target_gdbarch ()); + gdbpy_enter enter_py (objfile->arch ()); - if (objfile == NULL) - { - if (emit_clear_objfiles_event (current_program_space) < 0) - gdbpy_print_stack (); - } - else - { - if (emit_new_objfile_event (objfile) < 0) - gdbpy_print_stack (); - } + if (emit_new_objfile_event (objfile) < 0) + gdbpy_print_stack (); +} + +static void +python_all_objfiles_removed (program_space *pspace) +{ + if (!gdb_python_initialized) + return; + + gdbpy_enter enter_py (target_gdbarch ()); + + if (emit_clear_objfiles_event (pspace) < 0) + gdbpy_print_stack (); } /* Emit a Python event when an objfile is about to be removed. */ @@ -1020,6 +1022,8 @@ gdbpy_initialize_inferior (void) gdb::observers::new_objfile.attach (python_new_objfile, "py-inferior", { &auto_load_new_objfile_observer_token }); + gdb::observers::all_objfiles_removed.attach (python_all_objfiles_removed, + "py-inferior"); gdb::observers::free_objfile.attach (python_free_objfile, "py-inferior"); gdb::observers::inferior_added.attach (python_new_inferior, "py-inferior"); gdb::observers::inferior_removed.attach (python_inferior_deleted, diff --git a/gdb/remote.c b/gdb/remote.c index 9bb4f1de598..ae08c980efc 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -14963,14 +14963,12 @@ show_remote_cmd (const char *args, int from_tty) } } +/* Some change happened in PSPACE's objfile list (obfiles added or removed), + offer all inferiors using that program space a change to look up symbols. */ -/* Function to be called whenever a new objfile (shlib) is detected. */ static void -remote_new_objfile (struct objfile *objfile) +remote_objfile_changed_check_symbols (program_space *pspace) { - /* The objfile change happened in that program space. */ - program_space *pspace = current_program_space; - /* The affected program space is possibly shared by multiple inferiors. Consider sending a qSymbol packet for each of the inferiors using that program space. */ @@ -15019,6 +15017,14 @@ remote_new_objfile (struct objfile *objfile) } } +/* Function to be called whenever a new objfile (shlib) is detected. */ + +static void +remote_new_objfile (struct objfile *objfile) +{ + remote_objfile_changed_check_symbols (objfile->pspace); +} + /* Pull all the tracepoints defined on the target and create local data structures representing them. We don't want to create real tracepoints yet, we don't want to mess up the user's existing @@ -15333,6 +15339,8 @@ _initialize_remote () /* Hook into new objfile notification. */ gdb::observers::new_objfile.attach (remote_new_objfile, "remote"); + gdb::observers::all_objfiles_removed.attach + (remote_objfile_changed_check_symbols, "remote"); #if 0 init_remote_threadtests (); diff --git a/gdb/sol-thread.c b/gdb/sol-thread.c index ed1a803fbdb..c152b44dea6 100644 --- a/gdb/sol-thread.c +++ b/gdb/sol-thread.c @@ -668,8 +668,7 @@ check_for_thread_db (void) static void sol_thread_new_objfile (struct objfile *objfile) { - if (objfile != NULL) - check_for_thread_db (); + check_for_thread_db (); } /* Clean up after the inferior dies. */ diff --git a/gdb/symfile.c b/gdb/symfile.c index 584a62cd1d6..0f720d42c41 100644 --- a/gdb/symfile.c +++ b/gdb/symfile.c @@ -2915,7 +2915,7 @@ clear_symtab_users (symfile_add_flags add_flags) clear_displays (); clear_last_displayed_sal (); clear_pc_function_cache (); - gdb::observers::new_objfile.notify (NULL); + gdb::observers::all_objfiles_removed.notify (current_program_space); /* Now that the various caches have been cleared, we can re_set our breakpoints without risking it using stale data. */ diff --git a/gdb/symtab.c b/gdb/symtab.c index afad782fcdb..e9bc7b2c933 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -1695,13 +1695,18 @@ maintenance_print_symbol_cache_statistics (const char *args, int from_tty) static void symtab_new_objfile_observer (struct objfile *objfile) { - /* Ideally we'd use OBJFILE->pspace, but OBJFILE may be NULL. */ - symbol_cache_flush (current_program_space); + symbol_cache_flush (objfile->pspace); +} - /* When all objfiles have been removed (OBJFILE is nullptr), then forget - everything we know about the main function. */ - if (objfile == nullptr) - set_main_name (current_program_space, nullptr, language_unknown); +/* This module's 'all_objfiles_removed' observer. */ + +static void +symtab_all_objfiles_removed (program_space *pspace) +{ + symbol_cache_flush (pspace); + + /* Forget everything we know about the main function. */ + set_main_name (pspace, nullptr, language_unknown); } /* This module's 'free_objfile' observer. */ @@ -7022,5 +7027,7 @@ the use of prologue scanners."), deprecate_cmd (c, "maintenancelist flush symbol-cache"); gdb::observers::new_objfile.attach (symtab_new_objfile_observer, "symtab"); + gdb::observers::all_objfiles_removed.attach (symtab_all_objfiles_removed, + "symtab"); gdb::observers::free_objfile.attach (symtab_free_objfile_observer, "symtab"); } diff --git a/gdb/tui/tui-hooks.c b/gdb/tui/tui-hooks.c index d67c3d7f353..6525f0f2b6c 100644 --- a/gdb/tui/tui-hooks.c +++ b/gdb/tui/tui-hooks.c @@ -49,13 +49,20 @@ #include "gdb_curses.h" -static void -tui_new_objfile_hook (struct objfile* objfile) +static void tui_on_objfiles_changed () { if (tui_active) tui_display_main (); } +static void +tui_new_objfile_hook (struct objfile* objfile) +{ tui_on_objfiles_changed (); } + +static void +tui_all_objfiles_removed (program_space *pspace) +{ tui_on_objfiles_changed (); } + /* Prevent recursion of deprecated_register_changed_hook(). */ static bool tui_refreshing_registers = false; @@ -283,4 +290,6 @@ _initialize_tui_hooks () { /* Install the permanent hooks. */ gdb::observers::new_objfile.attach (tui_new_objfile_hook, "tui-hooks"); + gdb::observers::all_objfiles_removed.attach (tui_all_objfiles_removed, + "tui-hooks"); }