[RFA v2 07/13] Throw a "quit" on a KeyboardException in py-framefilter.c

Tom Tromey
2017-08-14T03:41:09Z

If a C-c comes while the Python code for a frame filter is running, it
will be turned into a Python KeyboardException. It seems good for
this to be treated like a GDB quit, so this patch changes
py-framefilter.c to notice this situation and call throw_quit in this
case.

ChangeLog
2017-08-13 Tom Tromey <tom@tromey.com>

* python/py-framefilter.c (throw_quit_or_print_exception): New
function.
(gdbpy_apply_frame_filter): Use it.

testsuite/ChangeLog
2017-08-13 Tom Tromey <tom@tromey.com>

* gdb.python/py-framefilter.exp: Add test for KeyboardInterrupt.
* gdb.python/py-framefilter.py (name_error): New global.
(ErrorInName.function): Use name_error.
---
gdb/ChangeLog | 6 ++++++
gdb/python/py-framefilter.c | 21 ++++++++++++++++++---
gdb/testsuite/ChangeLog | 6 ++++++
gdb/testsuite/gdb.python/py-framefilter.exp | 10 ++++++++++
gdb/testsuite/gdb.python/py-framefilter.py | 6 +++++-
5 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 825c099..33db802 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
2017-08-13 Tom Tromey <tom@tromey.com>

+ * python/py-framefilter.c (throw_quit_or_print_exception): New
+ function.
+ (gdbpy_apply_frame_filter): Use it.
+
+2017-08-13 Tom Tromey <tom@tromey.com>
+
PR cli/17716:
* python/py-framefilter.c (py_print_type, py_print_value)
(enumerate_args, py_print_args, gdbpy_apply_frame_filter): Use
diff --git a/gdb/python/py-framefilter.c b/gdb/python/py-framefilter.c
index e0a7bd0..76e637c 100644
--- a/gdb/python/py-framefilter.c
+++ b/gdb/python/py-framefilter.c
@@ -1305,6 +1305,21 @@ bootstrap_python_frame_filters (struct frame_info *frame,
return iterable.release ();
}

+/* A helper function that will either print an exception or, if it is
+ a KeyboardException, throw a quit. This can only be called when
+ the Python exception is set. */
+
+static void
+throw_quit_or_print_exception ()
+{
+ if (PyErr_ExceptionMatches (PyExc_KeyboardInterrupt))
+ {
+ PyErr_Clear ();
+ throw_quit ("Quit");
+ }
+ gdbpy_print_stack ();
+}
+
/* This is the only publicly exported function in this file. FRAME
is the source frame to start frame-filter invocation. FLAGS is an
integer holding the flags for printing. The following elements of
@@ -1363,7 +1378,7 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang,
initialization error. This return code will trigger a
default backtrace. */

- gdbpy_print_stack ();
+ throw_quit_or_print_exception ();
return EXT_LANG_BT_NO_FILTERS;
}

@@ -1386,7 +1401,7 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang,
{
if (PyErr_Occurred ())
{
- gdbpy_print_stack ();
+ throw_quit_or_print_exception ();
return EXT_LANG_BT_ERROR;
}
break;
@@ -1398,7 +1413,7 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang,
/* Do not exit on error printing a single frame. Print the
error and continue with other frames. */
if (success == EXT_LANG_BT_ERROR)
- gdbpy_print_stack ();
+ throw_quit_or_print_exception ();
}

return success;
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 53006d9..1bef7c6 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,11 @@
2017-08-13 Tom Tromey <tom@tromey.com>

+ * gdb.python/py-framefilter.exp: Add test for KeyboardInterrupt.
+ * gdb.python/py-framefilter.py (name_error): New global.
+ (ErrorInName.function): Use name_error.
+
+2017-08-13 Tom Tromey <tom@tromey.com>
+
PR backtrace/15582:
* gdb.python/py-framefilter.exp: Add "bt elide" test.

diff --git a/gdb/testsuite/gdb.python/py-framefilter.exp b/gdb/testsuite/gdb.python/py-framefilter.exp
index 80aa495..1a0572d 100644
--- a/gdb/testsuite/gdb.python/py-framefilter.exp
+++ b/gdb/testsuite/gdb.python/py-framefilter.exp
@@ -213,6 +213,16 @@ gdb_test_multiple "bt 1" $test {
}
}

+# Now verify that we can see a quit.
+gdb_test_no_output "python name_error = KeyboardInterrupt" \
+ "Change ErrorFilter to throw KeyboardInterrupt"
+set test "bt 1 with KeyboardInterrupt"
+gdb_test_multiple "bt 1" $test {
+ -re "Quit" {
+ pass $test
+ }
+}
+
# Test with no debuginfo

# We cannot use prepare_for_testing as we have to set the safe-patch
diff --git a/gdb/testsuite/gdb.python/py-framefilter.py b/gdb/testsuite/gdb.python/py-framefilter.py
index edd0e00..b579ec3 100644
--- a/gdb/testsuite/gdb.python/py-framefilter.py
+++ b/gdb/testsuite/gdb.python/py-framefilter.py
@@ -134,13 +134,17 @@ class FrameElider ():
def filter (self, frame_iter):
return ElidingIterator (frame_iter)

+# This is here so the test can change the kind of error that is
+# thrown.
+name_error = RuntimeError
+
# A simple decorator that gives an error when computing the function.
class ErrorInName(FrameDecorator):
def __init__(self, frame):
FrameDecorator.__init__(self, frame)

def function(self):
- raise RuntimeError('whoops')
+ raise name_error('whoops')

# A filter that supplies buggy frames. Disabled by default.
class ErrorFilter():
--
2.9.4