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[PATCH 1/3] Avoid find_thread_ptid with null_ptid
- From: Pedro Alves <palves at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Mon, 1 Oct 2018 11:32:50 +0100
- Subject: [PATCH 1/3] Avoid find_thread_ptid with null_ptid
- References: <20181001103252.5150-1-palves@redhat.com>
With a following patch, find_thread_ptid will first find the inferior
for the passed-in ptid, using find_inferior_pid, and then look for the
thread in that inferior's thread list. If we pass down null_ptid to
find_thread_ptid then that means we'll end up passing 0 to
find_inferior_pid, which hits this assertion:
> struct inferior *
> find_inferior_pid (int pid)
> {
> struct inferior *inf;
>
> /* Looking for inferior pid == 0 is always wrong, and indicative of
> a bug somewhere else. There may be more than one with pid == 0,
> for instance. */
> gdb_assert (pid != 0);
This patch prepares for the change, by avoiding passing down null_ptid
to find_thread_ptid or to functions that naturally use it, such as the
target_pid_to_str call in inferior.c:add_inferior. In that latter
case, the patch changes GDB output,
from:
(gdb) add-inferior
[New inferior 2 (process 0)]
to:
(gdb) add-inferior
[New inferior 2]
which seems like a good change to me. It might not even make sense to
talk about "process" for the current target, for example.
The python_on_normal_stop change ends up avoiding looking up the
same thread twice (inferior_thread also does a look up).
gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>
* cli/cli-interp.c (cli_on_user_selected_context_changed): Use
inferior_thread instead of find_thread_ptid, and only when
inferior_ptid is not null_ptid.
* inferior.c (add_inferior): Don't include target_pid_to_str
output when the inferior is not started.
* python/py-inferior.c (python_on_normal_stop): Don't use
find_thread_ptid.
(tui_on_user_selected_context_changed): Use inferior_thread
instead of find_thread_ptid, and only when inferior_ptid is not
null_ptid.
---
gdb/cli/cli-interp.c | 4 +---
gdb/inferior.c | 11 ++++++++---
gdb/python/py-inferior.c | 4 ++--
gdb/tui/tui-interp.c | 4 +---
4 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/gdb/cli/cli-interp.c b/gdb/cli/cli-interp.c
index 2aa41d6c8b..2d8482fa49 100644
--- a/gdb/cli/cli-interp.c
+++ b/gdb/cli/cli-interp.c
@@ -251,13 +251,11 @@ cli_on_command_error (void)
static void
cli_on_user_selected_context_changed (user_selected_what selection)
{
- struct thread_info *tp;
-
/* This event is suppressed. */
if (cli_suppress_notification.user_selected_context)
return;
- tp = find_thread_ptid (inferior_ptid);
+ thread_info *tp = inferior_ptid != null_ptid ? inferior_thread () : NULL;
SWITCH_THRU_ALL_UIS ()
{
diff --git a/gdb/inferior.c b/gdb/inferior.c
index 17d28c4cf5..394386a4b7 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -122,9 +122,14 @@ add_inferior (int pid)
struct inferior *inf = add_inferior_silent (pid);
if (print_inferior_events)
- printf_unfiltered (_("[New inferior %d (%s)]\n"),
- inf->num,
- target_pid_to_str (ptid_t (pid)));
+ {
+ if (pid != 0)
+ printf_unfiltered (_("[New inferior %d (%s)]\n"),
+ inf->num,
+ target_pid_to_str (ptid_t (pid)));
+ else
+ printf_unfiltered (_("[New inferior %d]\n"), inf->num);
+ }
return inf;
}
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index 5bba676478..7f8644b94b 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -86,8 +86,8 @@ python_on_normal_stop (struct bpstats *bs, int print_frame)
if (!gdb_python_initialized)
return;
- if (!find_thread_ptid (inferior_ptid))
- return;
+ if (inferior_ptid == null_ptid)
+ return;
stop_signal = inferior_thread ()->suspend.stop_signal;
diff --git a/gdb/tui/tui-interp.c b/gdb/tui/tui-interp.c
index acc8f0371c..a4f3925198 100644
--- a/gdb/tui/tui-interp.c
+++ b/gdb/tui/tui-interp.c
@@ -210,13 +210,11 @@ tui_on_command_error (void)
static void
tui_on_user_selected_context_changed (user_selected_what selection)
{
- struct thread_info *tp;
-
/* This event is suppressed. */
if (cli_suppress_notification.user_selected_context)
return;
- tp = find_thread_ptid (inferior_ptid);
+ thread_info *tp = inferior_ptid != null_ptid ? inferior_thread () : NULL;
SWITCH_THRU_ALL_UIS ()
{
--
2.14.4