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* [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning
@ 2010-07-26 16:11 tromey at gcc dot gnu dot org
2010-07-26 16:13 ` [Bug tree-optimization/45085] " tromey at gcc dot gnu dot org
` (8 more replies)
0 siblings, 9 replies; 10+ messages in thread
From: tromey at gcc dot gnu dot org @ 2010-07-26 16:11 UTC (permalink / raw)
To: gcc-bugs
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1812 bytes --]
I'm using a relatively recent svn trunk gcc on an x86 Fedora 13 machine.
I'm trying to compile gdb with it. I got this error:
../../archer/gdb/remote.c: In function remote_wait:
../../archer/gdb/remote.c:5561:10: error: event_ptid.tid may be used
uninitialized in this function [-Werror=uninitialized]
../../archer/gdb/remote.c:5561:10: error: event_ptid.lwp may be used
uninitialized in this function [-Werror=uninitialized]
../../archer/gdb/remote.c:5561:10: error: event_ptid.pid may be used
uninitialized in this function [-Werror=uninitialized]
cc1: all warnings being treated as errors
But the body of remote_wait is simple:
{
ptid_t event_ptid;
if (non_stop)
event_ptid = remote_wait_ns (ptid, status, options);
else
event_ptid = remote_wait_as (ptid, status, options);
if (target_can_async_p ())
{
/* If there are are events left in the queue tell the event loop
to return here. */
if (stop_reply_queue)
mark_async_event_handler (remote_async_inferior_event_token);
}
return event_ptid;
}
I thought perhaps that inlining was causing a problem (in which case this
error message is quite confusing, since it would point to the wrong function).
However, I added this:
memset (&event_ptid, 0, sizeof (event_ptid));
... to the function before the "if", and the error went away.
So, I think this is a gcc bug.
I will attach the .i file.
--
Summary: incorrect -Wuninitialized warning
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tromey at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
@ 2010-07-26 16:13 ` tromey at gcc dot gnu dot org
2010-07-27 12:42 ` jakub at gcc dot gnu dot org
` (7 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: tromey at gcc dot gnu dot org @ 2010-07-26 16:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from tromey at gcc dot gnu dot org 2010-07-26 16:12 -------
Created an attachment (id=21319)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21319&action=view)
compressed .i file
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
2010-07-26 16:13 ` [Bug tree-optimization/45085] " tromey at gcc dot gnu dot org
@ 2010-07-27 12:42 ` jakub at gcc dot gnu dot org
2010-07-27 12:58 ` jakub at gcc dot gnu dot org
` (6 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2010-07-27 12:42 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from jakub at gcc dot gnu dot org 2010-07-27 12:42 -------
Simplified testcase for -m32 -O2 -Wuninitialized:
struct S { char *s1; long s2; };
struct T { int t1; long t2; long t3; };
extern int fn2 (void);
extern int fn3 (struct T);
extern struct T fn4 ();
extern int fn5 (char **, long *, int);
extern void fn6 (void);
extern void fn7 (void *);
struct S *fn10 ();
static int p;
static void *q;
extern struct T r;
static struct T
fn8 (struct T x, int y)
{
struct S *u = fn10 ();
int v = fn5 (&u->s1, &u->s2, 0);
while (1)
{
if (p)
fn6 ();
if (fn3 (x))
return fn4 ();
if (y & 1)
return r;
v = fn5 (&u->s1, &u->s2, 1);
}
}
struct T
fn9 (struct T x, int y)
{
struct T t = fn8 (x, y);
if (fn2 ())
fn7 (q);
return t;
}
void *
fn1 (void)
{
return fn9;
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
2010-07-26 16:13 ` [Bug tree-optimization/45085] " tromey at gcc dot gnu dot org
2010-07-27 12:42 ` jakub at gcc dot gnu dot org
@ 2010-07-27 12:58 ` jakub at gcc dot gnu dot org
2010-07-27 13:25 ` [Bug tree-optimization/45085] [4.6 Regression] " jakub at gcc dot gnu dot org
` (5 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2010-07-27 12:58 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from jakub at gcc dot gnu dot org 2010-07-27 12:58 -------
Seems to be caused by partial inlining.
fnsplit splits off the:
q.0D.2030_3 = qD.1248;
fn7 (q.0D.2030_3);
part of fn9 into fn9.part.0:
fn9.part.0 ()
{
intD.0 D.2054;
voidD.32 * q.0D.2053;
struct T tD.2052;
struct T xD.2050;
intD.0 yD.2051;
<bb 4>:
<bb 2>:
q.0D.2053_1 = qD.1248;
fn7 (q.0D.2053_1);
<bb 3>:
<retval> = tD.2052;
return <retval>;
}
and uses:
tD.1261 = fn9.part.0 (); [return slot optimization]
in fn9 instead. tD.2052 isn't initialized anywhere though (and, it is unclear
why it did that at all, as that hunk doesn't modify t). Perhaps with -m32 and
aggregate return (where in the end t will be returned via hidden reference) t
is addressable? In any case, this is fnsplit bug.
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hubicka at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] [4.6 Regression] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
` (2 preceding siblings ...)
2010-07-27 12:58 ` jakub at gcc dot gnu dot org
@ 2010-07-27 13:25 ` jakub at gcc dot gnu dot org
2010-07-27 14:13 ` hubicka at gcc dot gnu dot org
` (4 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2010-07-27 13:25 UTC (permalink / raw)
To: gcc-bugs
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Known to fail| |4.6.0
Known to work| |4.5.0
Last reconfirmed|0000-00-00 00:00:00 |2010-07-27 13:25:07
date| |
Summary|incorrect -Wuninitialized |[4.6 Regression] incorrect -
|warning |Wuninitialized warning
Target Milestone|--- |4.6.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] [4.6 Regression] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
` (3 preceding siblings ...)
2010-07-27 13:25 ` [Bug tree-optimization/45085] [4.6 Regression] " jakub at gcc dot gnu dot org
@ 2010-07-27 14:13 ` hubicka at gcc dot gnu dot org
2010-08-03 12:09 ` hubicka at gcc dot gnu dot org
` (3 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: hubicka at gcc dot gnu dot org @ 2010-07-27 14:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from hubicka at gcc dot gnu dot org 2010-07-27 14:13 -------
Hmm, mine :)
Honza
--
hubicka at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |hubicka at gcc dot gnu dot
|dot org |org
Status|NEW |ASSIGNED
Last reconfirmed|2010-07-27 13:25:07 |2010-07-27 14:13:35
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] [4.6 Regression] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
` (4 preceding siblings ...)
2010-07-27 14:13 ` hubicka at gcc dot gnu dot org
@ 2010-08-03 12:09 ` hubicka at gcc dot gnu dot org
2010-09-02 11:11 ` rguenth at gcc dot gnu dot org
` (2 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: hubicka at gcc dot gnu dot org @ 2010-08-03 12:09 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from hubicka at gcc dot gnu dot org 2010-08-03 12:08 -------
Created an attachment (id=21374)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21374&action=view)
patch I am testing.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] [4.6 Regression] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
` (5 preceding siblings ...)
2010-08-03 12:09 ` hubicka at gcc dot gnu dot org
@ 2010-09-02 11:11 ` rguenth at gcc dot gnu dot org
2010-09-02 22:59 ` manu at gcc dot gnu dot org
2010-09-03 9:11 ` jakub at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2010-09-02 11:11 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from rguenth at gcc dot gnu dot org 2010-09-02 11:11 -------
This is fixed now?
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |WAITING
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] [4.6 Regression] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
` (6 preceding siblings ...)
2010-09-02 11:11 ` rguenth at gcc dot gnu dot org
@ 2010-09-02 22:59 ` manu at gcc dot gnu dot org
2010-09-03 9:11 ` jakub at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: manu at gcc dot gnu dot org @ 2010-09-02 22:59 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from manu at gcc dot gnu dot org 2010-09-02 22:59 -------
WAITING is for waiting for submitters information.
--
manu at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
OtherBugsDependingO| |24639
nThis| |
Status|WAITING |ASSIGNED
Keywords| |patch
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/45085] [4.6 Regression] incorrect -Wuninitialized warning
2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
` (7 preceding siblings ...)
2010-09-02 22:59 ` manu at gcc dot gnu dot org
@ 2010-09-03 9:11 ` jakub at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2010-09-03 9:11 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from jakub at gcc dot gnu dot org 2010-09-03 09:10 -------
Seems http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=162842
has been committed, just Honza forgot to mention the PR in the ChangeLog,
testcase and commit message.
I certainly can't reproduce this bug with 20100811 gcc and later, while I can
with 20100730.
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45085
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2010-09-03 9:11 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2010-07-26 16:11 [Bug tree-optimization/45085] New: incorrect -Wuninitialized warning tromey at gcc dot gnu dot org
2010-07-26 16:13 ` [Bug tree-optimization/45085] " tromey at gcc dot gnu dot org
2010-07-27 12:42 ` jakub at gcc dot gnu dot org
2010-07-27 12:58 ` jakub at gcc dot gnu dot org
2010-07-27 13:25 ` [Bug tree-optimization/45085] [4.6 Regression] " jakub at gcc dot gnu dot org
2010-07-27 14:13 ` hubicka at gcc dot gnu dot org
2010-08-03 12:09 ` hubicka at gcc dot gnu dot org
2010-09-02 11:11 ` rguenth at gcc dot gnu dot org
2010-09-02 22:59 ` manu at gcc dot gnu dot org
2010-09-03 9:11 ` jakub at gcc dot gnu dot org
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