Re: [PATCH] gdb: add load-libthread-db-quietly option

[Gregory Heytings <gregory@heytings.org>]

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Thanks for the review!  Updated patch attached.

>> In line with the Unix tradition in which no messages are displayed when 
>> no error happens, I suggest the attached patch, with which users could 
>> "set load-libthread-db-quietly off" in their .gdbinit file.
>
> You mean, "on", right?  Because "off" is the default.
>

Correct.

>
> There should be a NEWS entry about this new knob.
>

Now done.

>
> This description seems to be backwards, no?  The option, when ON, causes 
> the messages NOT to be displayed, right?  So I suggest
>
>  Turns on or off quiet loading of @code{libthread_db}.  When @code{on},
>  @value{GDBN} loads @code{libthread_db} quietly, without any messages.
>  The default is @code{off}.
>

Also correct.

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From 3713bf59d4d4ef43e528a8b6095a9bdca2fed734 Mon Sep 17 00:00:00 2001
From: Gregory Heytings <gregory@heytings.org>
Date: Sat, 1 Mar 2025 11:56:42 +0000
Subject: [PATCH] gdb: add load-libthread-db-quietly option

Setting that option disables the "Thread debugging using libthread_db
enabled" and "Using host libthread_db library..." messages.
---
 gdb/NEWS              |  3 +++
 gdb/doc/gdb.texinfo   |  8 ++++++++
 gdb/linux-thread-db.c | 29 ++++++++++++++++++++++++++---
 3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index f5dbf5c3350..4e10d58642f 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -40,6 +40,9 @@ show riscv numeric-register-names
   (e.g 'x1') or their abi names (e.g. 'ra').
   Defaults to 'off', matching the old behaviour (abi names).
 
+set load-libthread-db-quietly on|off
+  Controls whether GDB displays messages when loading libthread_db.
+
 * Python API
 
   ** New class gdb.Color for dealing with colors.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 29c0118dda2..4b752a15c42 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -4073,6 +4073,14 @@ only on some platforms.
 @item show libthread-db-search-path 
 Display current libthread_db search path.
 
+@kindex set load-libthread-db-quietly
+@kindex show load-libthread-db-quietly
+@item set load-libthread-db-quietly
+@itemx show load-libthread-db-quietly
+Turns on or off quiet loading of @code{libthread_db}.  When
+@code{on}, @value{GDBN} loads @code{libthread_db} quietly, without
+any messages.  The default is @code{off}.
+
 @kindex set debug libthread-db
 @kindex show debug libthread-db
 @cindex debugging @code{libthread_db}
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index 9d84187a9ad..d042d51c5fd 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -120,6 +120,9 @@ static bool auto_load_thread_db = true;
    by the "maintenance set check-libthread-db" command.  */
 static bool check_thread_db_on_load = false;
 
+/* Set to true if loading libthread_db happens quietly.  */
+static bool load_libthread_db_quiet = false;
+
 /* "show" command for the auto_load_thread_db configuration variable.  */
 
 static void
@@ -150,6 +153,15 @@ show_libthread_db_debug (struct ui_file *file, int from_tty,
   gdb_printf (file, _("libthread-db debugging is %s.\n"), value);
 }
 
+/* "show" command for the load_libthread_db_quiet configuration variable.  */
+
+static void
+show_load_libthread_db_quiet (struct ui_file *file, int from_tty,
+			      struct cmd_list_element *c, const char* value)
+{
+  gdb_printf (file, _("Loading libthread_db quietly is %s.\n"), value);
+}
+
 /* If we're running on GNU/Linux, we must explicitly attach to any new
    threads.  */
 
@@ -936,7 +948,8 @@ try_thread_db_load_1 (struct thread_db_info *info)
       return false;
     }
 
-  gdb_printf (_("[Thread debugging using libthread_db enabled]\n"));
+  if (!load_libthread_db_quiet)
+    gdb_printf (_("[Thread debugging using libthread_db enabled]\n"));
 
   if (!libthread_db_search_path.empty () || libthread_db_debug)
     {
@@ -946,8 +959,9 @@ try_thread_db_load_1 (struct thread_db_info *info)
       if (library == NULL)
 	library = LIBTHREAD_DB_SO;
 
-      gdb_printf (_("Using host libthread_db library \"%ps\".\n"),
-		  styled_string (file_name_style.style (), library));
+      if (!load_libthread_db_quiet)
+	gdb_printf (_("Using host libthread_db library \"%ps\".\n"),
+		    styled_string (file_name_style.style (), library));
     }
 
   /* The thread library was detected.  Activate the thread_db target
@@ -2050,6 +2064,15 @@ as they are loaded."),
 			   &maintenance_set_cmdlist,
 			   &maintenance_show_cmdlist);
 
+  add_setshow_boolean_cmd ("load-libthread-db-quietly", class_support,
+			   &load_libthread_db_quiet, _("\
+Set whether GDB should load libthread_db quietly."), _("\
+Show whether GDB should start load libthread_db quietly."), _("\
+If enabled, GDB will load libthread_db without printing messages."),
+			   NULL,
+			   show_load_libthread_db_quiet,
+			   &setlist, &showlist);
+
   /* Add ourselves to objfile event chain.  */
   gdb::observers::new_objfile.attach (thread_db_new_objfile, "linux-thread-db");
 
-- 
2.39.2