[RFA v2 03/13] Allow elision of some filtered frames

Tom Tromey
2017-08-14T03:41:32Z

When a frame filter elides some frames, they are still printed by
"bt", indented a few spaces. PR backtrace/15582 notes that it would
be nice for users if elided frames could simply be dropped. This
patch adds this capability.

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

PR backtrace/15582:
* stack.c (backtrace_command): Parse "elide" argument.
* python/py-framefilter.c (py_print_frame): Handle PRINT_ELIDE.
* extension.h (enum frame_filter_flags) <PRINT_ELIDE>: New
constant.

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

PR backtrace/15582:
* gdb.texinfo (Backtrace): Mention "elide" argument.

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

PR backtrace/15582:
* gdb.python/py-framefilter.exp: Add "bt elide" test.
---
gdb/ChangeLog | 8 +++++
gdb/doc/ChangeLog | 5 +++
gdb/doc/gdb.texinfo | 6 ++++
gdb/extension.h | 3 ++
gdb/python/py-framefilter.c | 50 ++++++++++++++---------------
gdb/stack.c | 2 ++
gdb/testsuite/ChangeLog | 5 +++
gdb/testsuite/gdb.python/py-framefilter.exp | 3 ++
8 files changed, 57 insertions(+), 25 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bd18b53..dd6459e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
2017-08-13 Tom Tromey <tom@tromey.com>

+ PR backtrace/15582:
+ * stack.c (backtrace_command): Parse "elide" argument.
+ * python/py-framefilter.c (py_print_frame): Handle PRINT_ELIDE.
+ * extension.h (enum frame_filter_flags) <PRINT_ELIDE>: New
+ constant.
+
+2017-08-13 Tom Tromey <tom@tromey.com>
+
* stack.c (backtrace_command_1): Remove "show_locals" parameter,
add "flags".
(backtrace_command): Remove "fulltrace", add "flags".
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 2592745..4992fe5 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,5 +1,10 @@
2017-08-13 Tom Tromey <tom@tromey.com>

+ PR backtrace/15582:
+ * gdb.texinfo (Backtrace): Mention "elide" argument.
+
+2017-08-13 Tom Tromey <tom@tromey.com>
+
* gdb.texinfo (Backtrace): Describe options individually.

2017-08-12 Sergio Durigan Junior <sergiodj@redhat.com>
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index bd19d4a..3f77114 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -7226,6 +7226,12 @@ Filter API}, for more information. Additionally use @ref{disable
frame-filter all} to turn off all frame filters. This is only
relevant when @value{GDBN} has been configured with @code{Python}
support.
+
+@item backtrace elide
+A Python frame filter might decide to ``elide'' some frames. Normally
+such elided frames are still printed, but they are indented relative
+to the filtered frames that cause them to be elided. The @code{elide}
+option causes elided frames to not be printed at all.
@end table

@kindex where
diff --git a/gdb/extension.h b/gdb/extension.h
index 2c79411..7c35502 100644
--- a/gdb/extension.h
+++ b/gdb/extension.h
@@ -100,6 +100,9 @@ enum frame_filter_flags

/* Set this flag if frame locals are to be printed. */
PRINT_LOCALS = 8,
+
+ /* Set this flag if elided frames should not be printed. */
+ PRINT_ELIDE = 32,
};

/* A choice of the different frame argument printing strategies that
diff --git a/gdb/python/py-framefilter.c b/gdb/python/py-framefilter.c
index 75b055c..f0474a9 100644
--- a/gdb/python/py-framefilter.c
+++ b/gdb/python/py-framefilter.c
@@ -1238,37 +1238,37 @@ py_print_frame (PyObject *filter, int flags,
return EXT_LANG_BT_ERROR;
}

- {
- /* Finally recursively print elided frames, if any. */
- gdbpy_ref<> elided (get_py_iter_from_func (filter, "elided"));
- if (elided == NULL)
- return EXT_LANG_BT_ERROR;
+ if ((flags & PRINT_ELIDE) == 0)
+ {
+ /* Finally recursively print elided frames, if any. */
+ gdbpy_ref<> elided (get_py_iter_from_func (filter, "elided"));
+ if (elided == NULL)
+ return EXT_LANG_BT_ERROR;

- if (elided != Py_None)
- {
- PyObject *item;
+ if (elided != Py_None)
+ {
+ PyObject *item;

- ui_out_emit_list inner_list_emiter (out, "children");
+ ui_out_emit_list inner_list_emiter (out, "children");

- if (! out->is_mi_like_p ())
- indent++;
+ if (! out->is_mi_like_p ())
+ indent++;

- while ((item = PyIter_Next (elided.get ())))
- {
- gdbpy_ref<> item_ref (item);
+ while ((item = PyIter_Next (elided.get ())))
+ {
+ gdbpy_ref<> item_ref (item);

- enum ext_lang_bt_status success = py_print_frame (item, flags,
- args_type, out,
- indent,
- levels_printed);
+ enum ext_lang_bt_status success
+ = py_print_frame (item, flags, args_type, out, indent,
+ levels_printed);

- if (success == EXT_LANG_BT_ERROR)
- return EXT_LANG_BT_ERROR;
- }
- if (item == NULL && PyErr_Occurred ())
- return EXT_LANG_BT_ERROR;
- }
- }
+ if (success == EXT_LANG_BT_ERROR)
+ return EXT_LANG_BT_ERROR;
+ }
+ if (item == NULL && PyErr_Occurred ())
+ return EXT_LANG_BT_ERROR;
+ }
+ }

return EXT_LANG_BT_COMPLETED;
}
diff --git a/gdb/stack.c b/gdb/stack.c
index be83f6d..30fd5ce 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -1888,6 +1888,8 @@ backtrace_command (char *arg, int from_tty)
filters = false;
else if (subset_compare (this_arg.get (), "full"))
flags |= PRINT_LOCALS;
+ else if (subset_compare (this_arg.get (), "elide"))
+ flags |= PRINT_ELIDE;
else
{
/* Not a recognized argument, so stop. */
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 23658b0..53006d9 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-08-13 Tom Tromey <tom@tromey.com>
+
+ PR backtrace/15582:
+ * gdb.python/py-framefilter.exp: Add "bt elide" test.
+
2017-08-12 Simon Marchi <simon.marchi@ericsson.com>

* lib/gdb.exp (get_valueof): Don't capture end-of-line
diff --git a/gdb/testsuite/gdb.python/py-framefilter.exp b/gdb/testsuite/gdb.python/py-framefilter.exp
index bbec48d..80aa495 100644
--- a/gdb/testsuite/gdb.python/py-framefilter.exp
+++ b/gdb/testsuite/gdb.python/py-framefilter.exp
@@ -157,6 +157,9 @@ gdb_test "bt no-filter full" \
gdb_test "bt full" \
".*#0.*end_func.*str = $hex \"The End\".*st2 = $hex \"Is Near\".*b = 12.*c = 5.*#1.*in funca \\(\\).*#2.*in funcb \\(j=10\\).*bar = \{a = 42, b = 84\}.*#22.*in func1 \\(\\).*#23.*in func2 \\(f=3\\).*elided = $hex \"Elided frame\".*fb = \{nothing = $hex \"Elided Foo Bar\", f = 84, s = 38\}.*bf = $hex.*" \
"bt full with Reverse disabled"
+gdb_test "bt full elide" \
+ ".*#0.*end_func.*str = $hex \"The End\".*st2 = $hex \"Is Near\".*b = 12.*c = 5.*#1.*in funca \\(\\).*#2.*in funcb \\(j=10\\).*bar = \{a = 42, b = 84\}.*#22.*in func1 \\(\\)\[^#\]*#24.*in func3 \\(i=3\\).*" \
+ "bt full elide with Reverse disabled"

# Test set print frame-arguments
# none
--
2.9.4