Allow 'interrupt -a' in all-stop mode

PR gdb/17160 points out that "interrupt -a" errors in all-stop mode,
but there's no good reason for this.  This patch removes the error.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17160

3 files changed, 74 insertions, 3 deletions

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index e909d4d..1859025 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -2874,9 +2874,6 @@ interrupt_command (const char *args, int from_tty)
 	  && startswith (args, "-a"))
 	all_threads = 1;
 
-      if (!non_stop && all_threads)
-	error (_("-a is meaningless in all-stop mode."));
-
       interrupt_target_1 (all_threads);
     }
 }
diff --git a/gdb/testsuite/gdb.base/interrupt-a.c b/gdb/testsuite/gdb.base/interrupt-a.c
new file mode 100644
index 0000000..2c12df2
--- /dev/null
+++ b/gdb/testsuite/gdb.base/interrupt-a.c
@@ -0,0 +1,27 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2022 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+
+int
+main ()
+{
+  int i;
+
+  for (i = 0; i < 60; ++i)
+    sleep (50);
+}
diff --git a/gdb/testsuite/gdb.base/interrupt-a.exp b/gdb/testsuite/gdb.base/interrupt-a.exp
new file mode 100644
index 0000000..e134f6e
--- /dev/null
+++ b/gdb/testsuite/gdb.base/interrupt-a.exp
@@ -0,0 +1,47 @@
+# Copyright (C) 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test that 'interrupt -a' works in all stop mode.
+
+standard_testfile .c
+set executable ${testfile}
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug}]} {
+    return -1
+}
+
+if {![runto_main]} {
+    return -1
+}
+
+gdb_test_multiple "continue &" "" {
+    -re "Continuing\\.\r\n$gdb_prompt " {
+	pass $gdb_test_name
+    }
+}
+
+after 200
+
+gdb_test_multiple "interrupt -a" "" {
+    -re "$gdb_prompt " {
+	pass $gdb_test_name
+    }
+}
+
+gdb_test_multiple "" "inferior stopped" {
+    -re "Program received signal" {
+	pass $gdb_test_name
+    }
+}