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From: "jonathan.hogg at stfc dot ac.uk" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/63489] New: stack allocated array pointer corrupted Date: Wed, 08 Oct 2014 16:01:00 -0000 [thread overview] Message-ID: <bug-63489-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63489 Bug ID: 63489 Summary: stack allocated array pointer corrupted Product: gcc Version: 4.8.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: jonathan.hogg at stfc dot ac.uk Created attachment 33667 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33667&action=edit test case The attached code, when compiled as g++ -g -O2 testcase.cxx -o testcase && ./testcase and run, produces: Try 0x7fff1cbe0a00 0x7fff1cbe0a00 Perm exit: 0 1 2 3 4 5 6 7 GO 0x7fff1cbe0a00 Try2 0x100000000 0x100000000 Segmentation fault g++ --version: g++ (Ubuntu 4.8.2-19ubuntu1) 4.8.2 Copyright (C) 2013 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. The lines "Try" and "Try2" should be identical, as they refer to the same stack-allocated array perm[]. Running under valgrind is clean until the last line of ldlt_test() is encountered (which is clearly a segfault as perm is a bad pointer). Compiling without -O2 changes something, and the code crashes differently. I can supply a larger test case (from which this was created) that shuold produce meaningful answers if the code works correctly, but it will need to be provided privately for IP reasons.
next reply other threads:[~2014-10-08 16:01 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-10-08 16:01 jonathan.hogg at stfc dot ac.uk [this message] 2014-10-08 17:53 ` [Bug c++/63489] " redi at gcc dot gnu.org 2014-10-08 17:53 ` redi at gcc dot gnu.org 2014-10-09 8:28 ` jonathan.hogg at stfc dot ac.uk 2014-10-09 12:36 ` redi at gcc dot gnu.org
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