Re: [RFA] Fix PR python/17981

Tom Tromey
2016-05-23T19:07:11Z

Yao> Yes, it is correct, but it is better to explicitly document an empty
Yao> sequence is returned if there are no breakpoints.

Here you go.

Tom

From 372c5d3e52de3695ca2148eb7683801285072c0c Mon Sep 17 00:00:00 2001
From: Tom Tromey <tom@tromey.com>
Date: Wed, 18 May 2016 21:41:28 -0600
Subject: [PATCH] Fix PR python/17981

PR python/17981 notes that gdb.breakpoints() returns None when there
are no breakpoints; whereas an empty list or tuple would be more in
keeping with Python and the documentation.

This patch fixes the bug by changing the no-breakpoint return to make
an empty tuple.

Built and regtested on x86-64 Fedora 23.

2016-05-23 Tom Tromey <tom@tromey.com>

PR python/17981:
* python/py-breakpoint.c (gdbpy_breakpoints): Return a new tuple
when there are no breakpoints.

2016-05-23 Tom Tromey <tom@tromey.com>

* python.texi (Basic Python): Document gdb.breakpoints return.

2016-05-23 Tom Tromey <tom@tromey.com>

PR python/17981:
* gdb.python/py-breakpoint.exp (test_bkpt_basic): Add test for
no-breakpoint case.
---
gdb/ChangeLog | 6 ++++++
gdb/doc/ChangeLog | 4 ++++
gdb/doc/python.texi | 5 ++++-
gdb/python/py-breakpoint.c | 4 ++--
gdb/testsuite/ChangeLog | 6 ++++++
gdb/testsuite/gdb.python/py-breakpoint.exp | 5 ++++-
6 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 07bc5d2..ef25519 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
2016-05-23 Tom Tromey <tom@tromey.com>

+ PR python/17981:
+ * python/py-breakpoint.c (gdbpy_breakpoints): Return a new tuple
+ when there are no breakpoints.
+
+2016-05-23 Tom Tromey <tom@tromey.com>
+
PR python/19438, PR python/18393:
* python/py-objfile.c (objfpy_initialize): Initialize self->dict.
* python/py-progspace.c (pspy_initialize): Initialize self->dict.
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index fe2e3be..3be4a88 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2016-05-23 Tom Tromey <tom@tromey.com>
+
+ * python.texi (Basic Python): Document gdb.breakpoints return.
+
2016-05-17 Tom Tromey <tom@tromey.com>

* gdb.texinfo (Supported Languages): Mention Rust. Update menu.
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index ffbf89a..6623d8e 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -236,7 +236,10 @@ and height, and its pagination will be disabled; @pxref{Screen Size}.
@findex gdb.breakpoints
@defun gdb.breakpoints ()
Return a sequence holding all of @value{GDBN}'s breakpoints.
-@xref{Breakpoints In Python}, for more information.
+@xref{Breakpoints In Python}, for more information. In @value{GDBN}
+version 7.11 and earlier, this function returned @code{None} if there
+were no breakpoints. This peculiarity was subsequently fixed, and now
+@code{gdb.breakpoints} returns an empty sequence in this case.
@end defun

@findex gdb.parameter
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 611a41e..ed9cae6 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -746,13 +746,13 @@ gdbpy_breakpoints (PyObject *self, PyObject *args)
PyObject *list, *tuple;

if (bppy_live == 0)
- Py_RETURN_NONE;
+ return PyTuple_New (0);

list = PyList_New (0);
if (!list)
return NULL;

- /* If iteratre_over_breakpoints returns non NULL it signals an error
+ /* If iterate_over_breakpoints returns non NULL it signals an error
condition. In that case abandon building the list and return
NULL. */
if (iterate_over_breakpoints (build_bp_list, list) != NULL)
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 1f0e3f9..afa358b 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,11 @@
2016-05-23 Tom Tromey <tom@tromey.com>

+ PR python/17981:
+ * gdb.python/py-breakpoint.exp (test_bkpt_basic): Add test for
+ no-breakpoint case.
+
+2016-05-23 Tom Tromey <tom@tromey.com>
+
PR python/19438, PR python/18393:
* gdb.python/py-progspace.exp: Add "dir" test.
* gdb.python/py-objfile.exp: Add "dir" test.
diff --git a/gdb/testsuite/gdb.python/py-breakpoint.exp b/gdb/testsuite/gdb.python/py-breakpoint.exp
index d1d1b22..f501aa9 100644
--- a/gdb/testsuite/gdb.python/py-breakpoint.exp
+++ b/gdb/testsuite/gdb.python/py-breakpoint.exp
@@ -34,12 +34,15 @@ proc test_bkpt_basic { } {
# Start with a fresh gdb.
clean_restart ${testfile}

+ # We should start with no breakpoints.
+ gdb_test "python print (gdb.breakpoints())" "\\(\\)"
+
if ![runto_main] then {
fail "Cannot run to main."
return 0
}

- # Initially there should be one breakpoint: main.
+ # Now there should be one breakpoint: main.
gdb_py_test_silent_cmd "python blist = gdb.breakpoints()" \
"Get Breakpoint List" 0
gdb_test "python print (blist\[0\])" \
--
2.5.5