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Re: [RFA 3/3] PR python/19293 - invalidate frame cache when unwinders change
- From: Tom Tromey <tom at tromey dot com>
- To: Pedro Alves <palves at redhat dot com>
- Cc: Tom Tromey <tom at tromey dot com>, gdb-patches at sourceware dot org
- Date: Thu, 23 Jun 2016 20:55:19 -0600
- Subject: Re: [RFA 3/3] PR python/19293 - invalidate frame cache when unwinders change
- Authentication-results: sourceware.org; auth=none
- References: <1465612923-24880-1-git-send-email-tom at tromey dot com> <1465612923-24880-4-git-send-email-tom at tromey dot com> <40f46408-1830-5929-5bee-fd49398900cf at redhat dot com>
Pedro> Seems reasonable to me. Couple nits below.
Here's the updated patch.
This still needs doc review.
Tom
commit dd5cd89e2345325da2361a3a72a11420de01e802
Author: Tom Tromey <tom@tromey.com>
Date: Thu Jun 9 15:20:09 2016 -0600
PR python/19293 - invalidate frame cache when unwinders change
PR python/19293 notes that when a Python unwinder is disabled, the
frame cache is not invalidated. This means that disabling an unwinder
doesn't have any immediate effect -- but in my experience it's often
the case that I want to enable or disable an unwinder in order to see
what happens.
This patch adds a new gdb.invalidate_cached_frames function and
arranges for the relevant bits of library code to call it. I've only
partially documented this function, considering a warning sufficient
without going into all the reasons ordinary code should not call it.
The name of the new function was taken from a comment in frame.h next
to reinit_frame_cache.
No new test as I think the updates to the existing test are sufficient
to show that the code is working as intended.
Built and regtested on x86-64 Fedora 23.
2016-06-23 Tom Tromey <tom@tromey.com>
PR python/19293:
* python/lib/gdb/command/unwinders.py (do_enable_unwinder): Call
gdb.invalidate_cached_frames.
* python/lib/gdb/unwinder.py (register_unwinder): Call
gdb.invalidate_cached_frames.
* python/python.c (gdbpy_invalidate_cached_frames): New function.
(python_GdbMethods): Add entry for invalidate_cached_frames.
2016-06-23 Tom Tromey <tom@tromey.com>
PR python/19293:
* python.texi (Frames In Python): Document
gdb.invalidate_cached_frames.
2016-06-23 Tom Tromey <tom@tromey.com>
PR python/19293:
* gdb.python/py-unwind-maint.exp: Update tests.
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 1ce5757..ee356bf 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2016-06-23 Tom Tromey <tom@tromey.com>
+
+ PR python/19293:
+ * python/lib/gdb/command/unwinders.py (do_enable_unwinder): Call
+ gdb.invalidate_cached_frames.
+ * python/lib/gdb/unwinder.py (register_unwinder): Call
+ gdb.invalidate_cached_frames.
+ * python/python.c (gdbpy_invalidate_cached_frames): New function.
+ (python_GdbMethods): Add entry for invalidate_cached_frames.
+
2016-06-09 Tom Tromey <tom@tromey.com>
* jit.c (jit_reader_load_command, jit_reader_unload_command): Call
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 3186ff2..3d051d8 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,9 @@
+2016-06-23 Tom Tromey <tom@tromey.com>
+
+ PR python/19293:
+ * python.texi (Frames In Python): Document
+ gdb.invalidate_cached_frames.
+
2016-06-21 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Interpreters): Update intepreter-exec section,
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 6623d8e..f218ad6 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -3838,6 +3838,15 @@ frames, as expressed by the given @var{reason} code (an integer, see the
@code{unwind_stop_reason} method further down in this section).
@end defun
+@findex gdb.invalidate_cached_frames
+@defun gdb.invalidate_cached_frames
+@value{GDBN} internally keeps a cache of the frames that have been
+unwound. This function invalidates this cache.
+
+This function should not generally be called by ordinary Python code.
+It is documented for the sake of completeness.
+@end defun
+
A @code{gdb.Frame} object has the following methods:
@defun Frame.is_valid ()
diff --git a/gdb/python/lib/gdb/command/unwinders.py b/gdb/python/lib/gdb/command/unwinders.py
index a9b9d8a..8fd0136 100644
--- a/gdb/python/lib/gdb/command/unwinders.py
+++ b/gdb/python/lib/gdb/command/unwinders.py
@@ -136,6 +136,8 @@ def do_enable_unwinder(arg, flag):
if locus_re.match(objfile.filename):
total += do_enable_unwinder1(objfile.frame_unwinders, name_re,
flag)
+ if total > 0:
+ gdb.invalidate_cached_frames()
print("%d unwinder%s %s" % (total, "" if total == 1 else "s",
"enabled" if flag else "disabled"))
diff --git a/gdb/python/lib/gdb/unwinder.py b/gdb/python/lib/gdb/unwinder.py
index 14b2758..67a37cb 100644
--- a/gdb/python/lib/gdb/unwinder.py
+++ b/gdb/python/lib/gdb/unwinder.py
@@ -92,3 +92,4 @@ def register_unwinder(locus, unwinder, replace=False):
unwinder.name)
i += 1
locus.frame_unwinders.insert(0, unwinder)
+ gdb.invalidate_cached_frames()
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 3a272a9..621e201 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -885,6 +885,15 @@ gdbpy_find_pc_line (PyObject *self, PyObject *args)
return result;
}
+/* Implementation of gdb.invalidate_cached_frames. */
+
+static PyObject *
+gdbpy_invalidate_cached_frames (PyObject *self, PyObject *args)
+{
+ reinit_frame_cache ();
+ Py_RETURN_NONE;
+}
+
/* Read a file as Python code.
This is the extension_language_script_ops.script_sourcer "method".
FILE is the file to load. FILENAME is name of the file FILE.
@@ -2071,6 +2080,12 @@ Return the selected inferior object." },
{ "inferiors", gdbpy_inferiors, METH_NOARGS,
"inferiors () -> (gdb.Inferior, ...).\n\
Return a tuple containing all inferiors." },
+
+ { "invalidate_cached_frames", gdbpy_invalidate_cached_frames, METH_NOARGS,
+ "invalidate_cached_frames () -> None.\n\
+Invalidate any cached frame objects in gdb.\n\
+Intended for internal use only." },
+
{NULL, NULL, 0, NULL}
};
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 8b5274d..ad11415 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,10 @@
2016-06-23 Tom Tromey <tom@tromey.com>
+ PR python/19293:
+ * gdb.python/py-unwind-maint.exp: Update tests.
+
+2016-06-23 Tom Tromey <tom@tromey.com>
+
PR gdb/16483:
* gdb.python/py-framefilter.exp: Add "info frame-filter" test
before any filters are loaded.
diff --git a/gdb/testsuite/gdb.python/py-unwind-maint.exp b/gdb/testsuite/gdb.python/py-unwind-maint.exp
index e89d284..3a98cb1 100644
--- a/gdb/testsuite/gdb.python/py-unwind-maint.exp
+++ b/gdb/testsuite/gdb.python/py-unwind-maint.exp
@@ -34,7 +34,11 @@ if ![runto_main ] then {
return -1
}
-gdb_test "source ${pyfile}" "Python script imported" "import python scripts"
+gdb_test_sequence "source ${pyfile}" "import python scripts" {
+ "Python script imported"
+ "py_unwind_maint_ps_unwinder called"
+ "global_unwinder called"
+}
gdb_test_sequence "info unwinder" "Show all unwinders" {
"Global:"
@@ -50,7 +54,10 @@ gdb_test_sequence "continue" "Unwinders called" {
"global_unwinder called"
}
-gdb_test "disable unwinder global .*" "1 unwinder disabled" "Unwinder disabled"
+gdb_test_sequence "disable unwinder global .*" "Unwinder disabled" {
+ "1 unwinder disabled"
+ "py_unwind_maint_ps_unwinder called"
+}
gdb_test_sequence "info unwinder" "Show with global unwinder disabled" {
"Global:"