[PATCH 01/12] gdb: add inferior_execd observable

Simon Marchi via Gdb-patches
2020-11-10T21:46:21Z

I want to add another action (clearing displaced stepping state) that
happens when an inferior execs. I think it would be cleaner to have an
observer for this event, rather than have infrun know about each other
sub-component.

Replace the calls to solib_create_inferior_hook and
jit_inferior_created_hook in follow_exec by observers.

gdb/ChangeLog:

* observable.h (inferior_execd): Declare new observable.
* observable.c (inferior_execd): Declare new observable.
* infrun.c (follow_exec): Notify inferior_execd observer.
* jit.c (jit_inferior_created_hook): Make static.
(_initialize_jit): Register inferior_execd observer.
* jit.h (jit_inferior_created_hook): Remove declaration.
* solib.c (_initialize_solib): Register inferior_execd observer.

Change-Id: I000cce00094e23baa67df693d912646b6ae38e44
---
gdb/infrun.c | 4 +---
gdb/jit.c | 9 +++++++--
gdb/jit.h | 7 -------
gdb/observable.c | 1 +
gdb/observable.h | 3 +++
gdb/solib.c | 4 ++++
6 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 990f40aa626..d59f6945285 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -1222,9 +1222,7 @@ follow_exec (ptid_t ptid, const char *exec_file_target)
registers. */
target_find_description ();

- solib_create_inferior_hook (0);
-
- jit_inferior_created_hook (inf);
+ gdb::observers::inferior_execd.notify (inf);

breakpoint_re_set ();

diff --git a/gdb/jit.c b/gdb/jit.c
index fd24d539159..9deeed7ab59 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -49,6 +49,7 @@ static const char jit_break_name[] = "__jit_debug_register_code";

static const char jit_descriptor_name[] = "__jit_debug_descriptor";

+static void jit_inferior_created_hook (inferior *inf);
static void jit_inferior_exit_hook (struct inferior *inf);

/* An unwinder is registered for every gdbarch. This key is used to
@@ -1230,9 +1231,12 @@ jit_inferior_init (inferior *inf)
}
}

-/* See jit.h. */
+/* Looks for the descriptor and registration symbols and breakpoints
+ the registration function. If it finds both, it registers all the
+ already JITed code. If it has already found the symbols, then it
+ doesn't try again. */

-void
+static void
jit_inferior_created_hook (inferior *inf)
{
jit_inferior_init (inf);
@@ -1337,6 +1341,7 @@ _initialize_jit ()
&setdebuglist, &showdebuglist);

gdb::observers::inferior_created.attach (jit_inferior_created_hook);
+ gdb::observers::inferior_execd.attach (jit_inferior_created_hook);
gdb::observers::inferior_exit.attach (jit_inferior_exit_hook);
gdb::observers::breakpoint_deleted.attach (jit_breakpoint_deleted);

diff --git a/gdb/jit.h b/gdb/jit.h
index 6f972a6e077..96938060733 100644
--- a/gdb/jit.h
+++ b/gdb/jit.h
@@ -103,13 +103,6 @@ struct jited_objfile_data
CORE_ADDR addr;
};

-/* Looks for the descriptor and registration symbols and breakpoints
- the registration function. If it finds both, it registers all the
- already JITed code. If it has already found the symbols, then it
- doesn't try again. */
-
-extern void jit_inferior_created_hook (inferior *inf);
-
/* Re-establish the jit breakpoint(s). */

extern void jit_breakpoint_re_set (void);
diff --git a/gdb/observable.c b/gdb/observable.c
index 81aa392cc21..231f955fa26 100644
--- a/gdb/observable.c
+++ b/gdb/observable.c
@@ -43,6 +43,7 @@ DEFINE_OBSERVABLE (command_error);
DEFINE_OBSERVABLE (target_changed);
DEFINE_OBSERVABLE (executable_changed);
DEFINE_OBSERVABLE (inferior_created);
+DEFINE_OBSERVABLE (inferior_execd);
DEFINE_OBSERVABLE (record_changed);
DEFINE_OBSERVABLE (solib_loaded);
DEFINE_OBSERVABLE (solib_unloaded);
diff --git a/gdb/observable.h b/gdb/observable.h
index 9114b28d04f..1dce6746ff3 100644
--- a/gdb/observable.h
+++ b/gdb/observable.h
@@ -89,6 +89,9 @@ extern observable<> executable_changed;
information on the inferior has been printed. */
extern observable<inferior */* inferior */> inferior_created;

+/* The inferior INF has exec'ed a new executable file. */
+extern observable<struct inferior */* inf */> inferior_execd;
+
/* The status of process record for inferior inferior in gdb has
changed. The process record is started if STARTED is true, and
the process record is stopped if STARTED is false.
diff --git a/gdb/solib.c b/gdb/solib.c
index b11c6f38900..1f6e91599a5 100644
--- a/gdb/solib.c
+++ b/gdb/solib.c
@@ -1557,6 +1557,10 @@ _initialize_solib ()
solib_data = gdbarch_data_register_pre_init (solib_init);

gdb::observers::free_objfile.attach (remove_user_added_objfile);
+ gdb::observers::inferior_execd.attach ([] (inferior *inf)
+ {
+ solib_create_inferior_hook (0);
+ });

add_com ("sharedlibrary", class_files, sharedlibrary_command,
_("Load shared object library symbols for files matching REGEXP."));
--
2.28.0