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* [Bug sanitizer/65365] New: false positive signed negation
@ 2015-03-09 20:31 joerg.richter@pdv-fs.de
2015-03-09 20:45 ` [Bug sanitizer/65365] " mpolacek at gcc dot gnu.org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: joerg.richter@pdv-fs.de @ 2015-03-09 20:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
Bug ID: 65365
Summary: false positive signed negation
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: joerg.richter@pdv-fs.de
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
cat > t.c <<EOF
int neg( unsigned v )
{
return -(int)(v-1)-1;
}
int main( int, char** )
{
neg( 2147483648u );
return 0;
}
EOF
g++ -o t t.c -fsanitize=undefined
./t
Gives this output:
t.c:3:22: runtime error: negation of -2147483648 cannot be represented in type
'int'; cast to an unsigned type to negate this value to itself
AFAIKS all operations are defined.
If the subtraction with "-1" is removed the error about negation disappears.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug sanitizer/65365] false positive signed negation
2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
@ 2015-03-09 20:45 ` mpolacek at gcc dot gnu.org
2015-03-10 9:01 ` rguenth at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-03-09 20:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mpolacek at gcc dot gnu.org
--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
This has already been fixed on trunk. Not sure if the change is backportable.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug sanitizer/65365] false positive signed negation
2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
2015-03-09 20:45 ` [Bug sanitizer/65365] " mpolacek at gcc dot gnu.org
@ 2015-03-10 9:01 ` rguenth at gcc dot gnu.org
2015-03-10 10:47 ` mpolacek at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-03-10 9:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-03-10
Known to work| |5.0
Ever confirmed|0 |1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug sanitizer/65365] false positive signed negation
2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
2015-03-09 20:45 ` [Bug sanitizer/65365] " mpolacek at gcc dot gnu.org
2015-03-10 9:01 ` rguenth at gcc dot gnu.org
@ 2015-03-10 10:47 ` mpolacek at gcc dot gnu.org
2015-03-10 10:51 ` jakub at gcc dot gnu.org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-03-10 10:47 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.9.4
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed in r218395, probably eligible to backport. Jakub?
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug sanitizer/65365] false positive signed negation
2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
` (2 preceding siblings ...)
2015-03-10 10:47 ` mpolacek at gcc dot gnu.org
@ 2015-03-10 10:51 ` jakub at gcc dot gnu.org
2015-03-10 10:54 ` mpolacek at gcc dot gnu.org
2015-03-11 10:38 ` mpolacek at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: jakub at gcc dot gnu.org @ 2015-03-10 10:51 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Ok with me.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug sanitizer/65365] false positive signed negation
2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
` (3 preceding siblings ...)
2015-03-10 10:51 ` jakub at gcc dot gnu.org
@ 2015-03-10 10:54 ` mpolacek at gcc dot gnu.org
2015-03-11 10:38 ` mpolacek at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-03-10 10:54 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |mpolacek at gcc dot gnu.org
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Thanks - mine then.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug sanitizer/65365] false positive signed negation
2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
` (4 preceding siblings ...)
2015-03-10 10:54 ` mpolacek at gcc dot gnu.org
@ 2015-03-11 10:38 ` mpolacek at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-03-11 10:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65365
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed in 4.9.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2015-03-11 10:38 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2015-03-09 20:31 [Bug sanitizer/65365] New: false positive signed negation joerg.richter@pdv-fs.de
2015-03-09 20:45 ` [Bug sanitizer/65365] " mpolacek at gcc dot gnu.org
2015-03-10 9:01 ` rguenth at gcc dot gnu.org
2015-03-10 10:47 ` mpolacek at gcc dot gnu.org
2015-03-10 10:51 ` jakub at gcc dot gnu.org
2015-03-10 10:54 ` mpolacek at gcc dot gnu.org
2015-03-11 10:38 ` mpolacek at gcc dot gnu.org
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