gdb: add missing notify_breakpoint_modified call

The commit:

  commit b080fe54fb3414b488b8ef323c6c50def061f918
  Date:   Tue Nov 8 12:32:51 2022 +0000

      gdb: add inferior-specific breakpoints

introduced a bug in the function breakpoint_set_inferior. The above
commit includes this line:

  gdb::observers::breakpoint_modified.notify (b);

when it should have instead used this line:

  notify_breakpoint_modified (b);

The change to use notify_breakpoint_modified was introduced to GDB
after commit b080fe54fb34 was written, but before it was merged, and I
failed to update this part of the code during the rebase.

The consequence of this error is that the MI interpreter will not emit
breakpoint-modified notifications when breakpoint_set_inferior is
called.

In this commit I update the code to call notify_breakpoint_modified,
and add a test that checks the MI events are being emitted correctly
in this case.

4 files changed, 115 insertions, 1 deletions

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index f88ca1c..f0f5328 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1574,7 +1574,7 @@ breakpoint_set_inferior (struct breakpoint *b, int inferior)
   int old_inferior = b->inferior;
   b->inferior = inferior;
   if (old_inferior != inferior)
-    gdb::observers::breakpoint_modified.notify (b);
+    notify_breakpoint_modified (b);
 }
 
 /* See breakpoint.h.  */
diff --git a/gdb/testsuite/gdb.mi/mi-py-modify-bp.c b/gdb/testsuite/gdb.mi/mi-py-modify-bp.c
new file mode 100644
index 0000000..58546b3
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-py-modify-bp.c
@@ -0,0 +1,28 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright (C) 2023 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/>.  */
+
+int
+foo ()
+{
+  return 0;
+}
+
+int
+main ()
+{
+  return foo ();
+}
diff --git a/gdb/testsuite/gdb.mi/mi-py-modify-bp.exp b/gdb/testsuite/gdb.mi/mi-py-modify-bp.exp
new file mode 100644
index 0000000..95a26ea
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-py-modify-bp.exp
@@ -0,0 +1,61 @@
+# Copyright (C) 2023 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/>.
+
+# Check that the MI interpreter correctly emits breakpoint-modified
+# notifications when a breakpoint's thread or inferior is set from
+# Python code.
+
+load_lib mi-support.exp
+set MIFLAGS "-i=mi"
+
+standard_testfile
+
+require allow_python_tests
+
+if {[build_executable $testfile.exp $testfile $srcfile] == -1} {
+    return -1
+}
+
+set remote_python_file [gdb_remote_download host \
+			    ${srcdir}/${subdir}/${testfile}.py]
+
+mi_clean_restart $binfile
+mi_runto_main
+
+# Delete all breakpoints.
+mi_delete_breakpoints
+
+# Create a breakpoint.  At this point the breakpoint is global, but
+# this will be adjusted from Python code.
+mi_create_breakpoint "foo" "break in foo" -disp keep -func foo
+set bpnum [mi_get_valueof "/d" "\$bpnum" "INVALID" \
+	       "get number for thread-specific breakpoint"]
+
+# Some patterns used in the expected output below.
+set thr_group_re [string_to_regexp {thread-groups=["i1"]}]
+set times_re [string_to_regexp {times="0"}]
+
+# Source the Python script, the script changes the thread then
+# inferior field of the first breakpoint, we expect to see the
+# breakpoint modified four times.
+mi_gdb_test "source $remote_python_file" \
+    [multi_line \
+	 "&\"source \[^\r\n\]+\"" \
+	 "=breakpoint-modified,bkpt=\\{number=\"$bpnum\",\[^\r\n\]+\\,$thr_group_re,thread=\"1\",$times_re,\[^\r\n\]+}" \
+	 "=breakpoint-modified,bkpt=\\{number=\"$bpnum\",\[^\r\n\]+\\,$thr_group_re,$times_re,\[^\r\n\]+}" \
+	 "=breakpoint-modified,bkpt=\\{number=\"$bpnum\",\[^\r\n\]+\\,$thr_group_re,inferior=\"1\",$times_re,\[^\r\n\]+}" \
+	 "=breakpoint-modified,bkpt=\\{number=\"$bpnum\",\[^\r\n\]+\\,$thr_group_re,$times_re,\[^\r\n\]+}" \
+	 "\\^done"] \
+    "source python script"
diff --git a/gdb/testsuite/gdb.mi/mi-py-modify-bp.py b/gdb/testsuite/gdb.mi/mi-py-modify-bp.py
new file mode 100644
index 0000000..6e1034c
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-py-modify-bp.py
@@ -0,0 +1,25 @@
+# Copyright (C) 2023 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/>.
+
+import gdb
+
+bps = gdb.breakpoints()
+bp = bps[0]
+
+bp.thread = 1
+bp.thread = None
+
+bp.inferior = 1
+bp.inferior = None