gdb: add "set startup-quietly" command

This adds a new command to change GDB to behave as though "-quiet"
were always given.  This new command can be added to the gdbearlyinit
file to affect future GDB sessions.

gdb/ChangeLog:

	* NEWS: Add entry.
	* main.c (captured_main_1): Call check_quiet_mode.
	* top.c (startup_quiet): New global.
	(check_quiet_mode): New function.
	(show_startup_quiet): New function.
	(init_main): Register new command.
	* top.h (check_quiet_mode): Declare.

gdb/doc/ChangeLog:

	* gdb.texinfo (Mode Options): Mention "set startup-quietly".

gdb/testsuite/ChangeLog:

	* gdb.base/startup-file.exp: Add more tests.

9 files changed, 117 insertions, 0 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ee3aeb8..5385058 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2021-04-15  Tom Tromey  <tom@tromey.com>
+	    Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* NEWS: Add entry.
+	* main.c (captured_main_1): Call check_quiet_mode.
+	* top.c (startup_quiet): New global.
+	(check_quiet_mode): New function.
+	(show_startup_quiet): New function.
+	(init_main): Register new command.
+	* top.h (check_quiet_mode): Declare.
+
 2021-04-15  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	PR cli/25956
diff --git a/gdb/NEWS b/gdb/NEWS
index c5f8605..faccf40 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -94,6 +94,13 @@ memory-tag set-allocation-tag ADDRESS LENGTH TAGS
 memory-tag check POINTER
   Validate that POINTER's logical tag matches the allocation tag.
 
+set startup-quietly on|off
+show startup-quietly
+  When 'on', this causes GDB to act as if "-silent" were passed on the
+  command line.  This command needs to be added to an early
+  initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
+  affect GDB.
+
 * Changed commands
 
 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index b27bd18..32801bf 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2021-04-15  Tom Tromey  <tom@tromey.com>
+	    Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* gdb.texinfo (Mode Options): Mention "set startup-quietly".
+
 2021-04-15  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	PR cli/25956
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 4351378..d13cbda 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -1112,6 +1112,14 @@ are still loaded.
 ``Quiet''.  Do not print the introductory and copyright messages.  These
 messages are also suppressed in batch mode.
 
+@kindex set startup-quietly
+@kindex show startup-quietly
+This can also be enabled using @code{set startup-quietly on}.  The
+default is @code{off}.  Use @code{show startup-quietly} to see the
+current setting.  Place @code{set startup-quietly on} into your early
+initialization file (@pxref{Initialization Files,,Initialization
+Files}) to have future @value{GDBN} sessions startup quietly.
+
 @item -batch
 @cindex @code{--batch}
 Run in batch mode.  Exit with status @code{0} after processing all the
diff --git a/gdb/main.c b/gdb/main.c
index 5633381..60c08fb 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -1053,6 +1053,11 @@ captured_main_1 (struct captured_main_args *context)
   execute_cmdargs (&cmdarg_vec, CMDARG_EARLYINIT_FILE,
 		   CMDARG_EARLYINIT_COMMAND, &ret);
 
+  /* Recheck if we're starting up quietly after processing the startup
+     scripts and commands.  */
+  if (!quiet)
+    quiet = check_quiet_mode ();
+
   /* Now that gdb_init has created the initial inferior, we're in
      position to set args for that inferior.  */
   if (set_args)
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 04872d8..f58d771 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,9 @@
 2021-04-15  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* gdb.base/startup-file.exp: Add more tests.
+
+2021-04-15  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	PR cli/25956
 	* gdb.base/early-init-file.c: New file.
 	* gdb.base/early-init-file.exp: New file.
diff --git a/gdb/testsuite/gdb.base/early-init-file.exp b/gdb/testsuite/gdb.base/early-init-file.exp
index 4873e5b..9d5e84c 100644
--- a/gdb/testsuite/gdb.base/early-init-file.exp
+++ b/gdb/testsuite/gdb.base/early-init-file.exp
@@ -66,6 +66,21 @@ proc setup_home_directories { prefix content } {
     return [list $home_dir $xdg_home_dir]
 }
 
+# Restart GDB and ensure that there's no license text, we should just
+# drop straight to the prompt.
+proc check_gdb_startups_up_quietly { message } {
+    global gdb_prompt
+
+    gdb_exit
+    gdb_spawn
+
+    gdb_test_multiple "" $message {
+	-re "^$gdb_prompt $" {
+	    pass $gdb_test_name
+	}
+    }
+}
+
 save_vars { env(TERM) } {
     # We need an ANSI-capable terminal to get the output.
     setenv TERM ansi
@@ -106,4 +121,28 @@ save_vars { env(TERM) } {
 	check_gdb_startup_version_string none \
 	    "check version string is unstyled using XDG_CONFIG_HOME"
     }
+
+    # Create two directories to use for the quiet startup test.
+    set dirs [setup_home_directories "quiet" "set startup-quietly on"]
+    set home_dir [lindex $dirs 0]
+    set xdg_home_dir [lindex $dirs 1]
+
+    # Now arrange to use the fake home directory startup file.
+    save_vars { INTERNAL_GDBFLAGS env(HOME) env(XDG_CONFIG_HOME) } {
+	set INTERNAL_GDBFLAGS [string map {"-nx" ""} $INTERNAL_GDBFLAGS]
+
+	# Now test GDB when using the HOME directory.
+	set env(HOME) $home_dir
+	unset -nocomplain env(XDG_CONFIG_HOME)
+	check_gdb_startups_up_quietly \
+	    "check GDB starts quietly using HOME"
+
+	# Now test using the XDG_CONFIG_HOME folder.  We still need to
+	# have a HOME directory set otherwise GDB will issue an error
+	# about not knowing where to place the index cache.
+	set env(XDG_CONFIG_HOME) $xdg_home_dir
+	set env(HOME) $empty_home_dir
+	check_gdb_startups_up_quietly \
+	    "check GDB starts quietly using XDG_CONFIG_HOME"
+    }
 }
diff --git a/gdb/top.c b/gdb/top.c
index c374a8d..ecd90a1 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -2163,6 +2163,28 @@ set_history_filename (const char *args,
     }
 }
 
+/* Whether we're in quiet startup mode.  */
+
+static bool startup_quiet;
+
+/* See top.h.  */
+
+bool
+check_quiet_mode ()
+{
+  return startup_quiet;
+}
+
+/* Show whether GDB should start up in quiet mode.  */
+
+static void
+show_startup_quiet (struct ui_file *file, int from_tty,
+	      struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file, _("Whether to start up quietly is %s.\n"),
+		    value);
+}
+
 static void
 init_gdb_version_vars (void)
 {
@@ -2319,6 +2341,17 @@ input settings."),
 			show_interactive_mode,
 			&setlist, &showlist);
 
+  c = add_setshow_boolean_cmd ("startup-quietly", class_support,
+			       &startup_quiet, _("\
+Set whether GDB should start up quietly."), _("		\
+Show whether GDB should start up quietly."), _("\
+This setting will not affect the current session.  Instead this command\n\
+should be added to the .gdbearlyinit file in the users home directory to\n\
+affect future GDB sessions."),
+			       NULL,
+			       show_startup_quiet,
+			       &setlist, &showlist);
+
   c = add_cmd ("new-ui", class_support, new_ui_command, _("\
 Create a new UI.\n\
 Usage: new-ui INTERPRETER TTY\n\
diff --git a/gdb/top.h b/gdb/top.h
index f58bebb..9438e52 100644
--- a/gdb/top.h
+++ b/gdb/top.h
@@ -291,4 +291,9 @@ extern char *handle_line_of_input (struct buffer *cmd_line_buffer,
 				   const char *rl, int repeat,
 				   const char *annotation_suffix);
 
+/* Call at startup to see if the user has requested that gdb start up
+   quietly.  */
+
+extern bool check_quiet_mode ();
+
 #endif