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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) -- links below jump to the message on this page -- 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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