diff options
Diffstat (limited to 'gdb/extension.c')
| -rw-r--r-- | gdb/extension.c | 120 |
1 files changed, 68 insertions, 52 deletions
diff --git a/gdb/extension.c b/gdb/extension.c index ec1aa13..1e967c5 100644 --- a/gdb/extension.c +++ b/gdb/extension.c @@ -1,6 +1,6 @@ /* Interface between gdb and its extension languages. - Copyright (C) 2014-2024 Free Software Foundation, Inc. + Copyright (C) 2014-2025 Free Software Foundation, Inc. This file is part of GDB. @@ -33,6 +33,9 @@ #include "guile/guile.h" #include <array> #include "inferior.h" +#include "gdbsupport/scoped_signal_handler.h" +#include "gdbsupport/scoped_ignore_signal.h" +#include "run-on-main-thread.h" static script_sourcer_func source_gdb_script; static objfile_script_sourcer_func source_gdb_objfile_script; @@ -84,7 +87,7 @@ const struct extension_language_defn extension_language_gdb = static const std::array<const extension_language_defn *, 2> extension_languages { - /* To preserve existing behaviour, python should always appear first. */ + /* To preserve existing behavior, python should always appear first. */ &extension_language_python, &extension_language_guile, }; @@ -297,28 +300,6 @@ ext_lang_auto_load_enabled (const struct extension_language_defn *extlang) } -/* RAII class used to temporarily return SIG to its default handler. */ - -template<int SIG> -struct scoped_default_signal -{ - scoped_default_signal () - { m_old_sig_handler = signal (SIG, SIG_DFL); } - - ~scoped_default_signal () - { signal (SIG, m_old_sig_handler); } - - DISABLE_COPY_AND_ASSIGN (scoped_default_signal); - -private: - /* The previous signal handler that needs to be restored. */ - sighandler_t m_old_sig_handler; -}; - -/* Class to temporarily return SIGINT to its default handler. */ - -using scoped_default_sigint = scoped_default_signal<SIGINT>; - /* Functions that iterate over all extension languages. These only iterate over external extension languages, not including GDB's own extension/scripting language, unless otherwise indicated. */ @@ -334,7 +315,7 @@ ext_lang_initialization (void) if (extlang->ops != nullptr && extlang->ops->initialize != NULL) { - scoped_default_sigint set_sigint_to_default_handler; + scoped_signal_handler<SIGINT> set_sigint_to_default_handler (SIG_DFL); extlang->ops->initialize (extlang); } } @@ -584,7 +565,8 @@ apply_ext_lang_ptwrite_filter (btrace_thread_info *btinfo) preserve_one_value. */ void -preserve_ext_lang_values (struct objfile *objfile, htab_t copied_types) +preserve_ext_lang_values (struct objfile *objfile, + copied_types_hash_t &copied_types) { for (const struct extension_language_defn *extlang : extension_languages) { @@ -658,7 +640,7 @@ breakpoint_ext_lang_cond_says_stop (struct breakpoint *b) This requires cooperation with the extension languages so the support is defined here. */ -#if CXX_STD_THREAD +#if CXX_STD_THREAD && defined __MINGW32__ #include <mutex> @@ -668,10 +650,19 @@ breakpoint_ext_lang_cond_says_stop (struct breakpoint *b) available, DAP will not start. This lock is held for accesses to quit_flag, active_ext_lang, and - cooperative_sigint_handling_disabled. */ + cooperative_sigint_handling_disabled. + + This lock is only required for targets that don't support kill(), and, + it is assumed, handle SIGINT not as a signal, but as a new thread. For + these targets this mutex prevents multiple threads adjusting the above + state at the same time. + + For targets that support kill() gdb.interrupt is implemented by just + sending SIGINT to the process, which is then handled in the "normal" + way. */ static std::recursive_mutex ext_lang_mutex; -#endif /* CXX_STD_THREAD */ +#endif /* CXX_STD_THREAD && defined (__MINGW32__)*/ /* This flag tracks quit requests when we haven't called out to an extension language. it also holds quit requests when we transition to @@ -720,6 +711,44 @@ void (*hook_set_active_ext_lang) () = nullptr; } #endif +namespace gdb +{ +/* Wrapper that acquires the global EXT_LANG_MUTEX, but only for hosts + that might call quit related functions from a separate thread. + Specifically, this is hosts that don't support Unix like signals + (currently only Mingw). + + For hosts with signal support, we don't try to use a mutex as a signal + might interrupt the lock acquisition, in which case deadlock will + occur. However, for these hosts, all the quit related functions are + called on the main thread (there's an assert for this), so the lack of + locking shouldn't be an issue. + + For Mingw, without signals, the implementation of the Python + gdb.interrupt function can call set_quit_flag() from a second thread, + and additionally, the emulation of SIGINT involves the creation of a + temporary thread which calls the sigint handler. So for Mingw, we do + need the mutex, but that's OK, as no signal can interrupt the lock + acquisition. */ +struct ext_lang_guard +{ + ext_lang_guard () + { +#if CXX_STD_THREAD && !defined __MINGW32__ + gdb_assert (is_main_thread ()); +#endif /* CXX_STD_THREAD && ! defined __MINGW32__ */ + } + + ~ext_lang_guard () { /* Nothing. */ } + +private: +#if CXX_STD_THREAD && defined __MINGW32__ + std::lock_guard<typeof (ext_lang_mutex)> m_guard { ext_lang_mutex }; +#endif +}; + +} + /* True if cooperative SIGINT handling is disabled. This is needed so that calls to set_active_ext_lang do not re-enable cooperative handling, which if enabled would make set_quit_flag store the @@ -728,9 +757,7 @@ static bool cooperative_sigint_handling_disabled = false; scoped_disable_cooperative_sigint_handling::scoped_disable_cooperative_sigint_handling () { -#if CXX_STD_THREAD - std::lock_guard guard (ext_lang_mutex); -#endif /* CXX_STD_THREAD */ + gdb::ext_lang_guard guard; /* Force the active extension language to the GDB scripting language. This ensures that a previously saved SIGINT is moved @@ -749,9 +776,7 @@ scoped_disable_cooperative_sigint_handling::scoped_disable_cooperative_sigint_ha scoped_disable_cooperative_sigint_handling::~scoped_disable_cooperative_sigint_handling () { -#if CXX_STD_THREAD - std::lock_guard guard (ext_lang_mutex); -#endif /* CXX_STD_THREAD */ + gdb::ext_lang_guard guard; cooperative_sigint_handling_disabled = m_prev_cooperative_sigint_handling_disabled; restore_active_ext_lang (m_prev_active_ext_lang_state); @@ -791,9 +816,7 @@ scoped_disable_cooperative_sigint_handling::~scoped_disable_cooperative_sigint_h struct active_ext_lang_state * set_active_ext_lang (const struct extension_language_defn *now_active) { -#if CXX_STD_THREAD - std::lock_guard guard (ext_lang_mutex); -#endif /* CXX_STD_THREAD */ + gdb::ext_lang_guard guard; #if GDB_SELF_TEST if (selftests::hook_set_active_ext_lang) @@ -847,9 +870,7 @@ set_active_ext_lang (const struct extension_language_defn *now_active) void restore_active_ext_lang (struct active_ext_lang_state *previous) { -#if CXX_STD_THREAD - std::lock_guard guard (ext_lang_mutex); -#endif /* CXX_STD_THREAD */ + gdb::ext_lang_guard guard; if (cooperative_sigint_handling_disabled) { @@ -881,9 +902,7 @@ restore_active_ext_lang (struct active_ext_lang_state *previous) void set_quit_flag () { -#if CXX_STD_THREAD - std::lock_guard guard (ext_lang_mutex); -#endif /* CXX_STD_THREAD */ + gdb::ext_lang_guard guard; if (active_ext_lang->ops != NULL && active_ext_lang->ops->set_quit_flag != NULL) @@ -906,9 +925,7 @@ set_quit_flag () bool check_quit_flag () { -#if CXX_STD_THREAD - std::lock_guard guard (ext_lang_mutex); -#endif /* CXX_STD_THREAD */ + gdb::ext_lang_guard guard; bool result = false; @@ -994,7 +1011,8 @@ xmethod_worker::get_result_type (value *object, gdb::array_view<value *> args) /* See extension.h. */ std::optional<std::string> -ext_lang_colorize (const std::string &filename, const std::string &contents) +ext_lang_colorize (const std::string &filename, const std::string &contents, + enum language lang) { std::optional<std::string> result; @@ -1003,7 +1021,7 @@ ext_lang_colorize (const std::string &filename, const std::string &contents) if (extlang->ops == nullptr || extlang->ops->colorize == nullptr) continue; - result = extlang->ops->colorize (filename, contents); + result = extlang->ops->colorize (filename, contents, lang); if (result.has_value ()) return result; } @@ -1121,9 +1139,7 @@ ext_lang_before_prompt (const char *current_gdb_prompt) } } -void _initialize_extension (); -void -_initialize_extension () +INIT_GDB_FILE (extension) { gdb::observers::before_prompt.attach (ext_lang_before_prompt, "extension"); } |