https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67315
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-08-22
Known to work| |4.8.4, 5.2.0, 6.0
Summary|Strange 'this' pointer |[4.9 Regression] Strange
|behavior when calling |'this' pointer behavior
|virtual function with |when calling virtual
|different optimization |function with different
|attributes. |optimization attributes.
Ever confirmed|0 |1
Known to fail| |4.9.3
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I can reproduce this with any 4.9.x release, but not with 5.x or trunk.
Doesn't happen for x86_64 only 32-bit. Only -O2 is needed.
$ ~/gcc/4.9.3/bin/g++ v.cc -Wall -O2 -m32
$ ./a.out
Init 0x8218a10
m_test = 4
Calling test11 0xf76a94ec
Calling test21 0xf76a94ec
$ valgrind ./a.out
==12566== Memcheck, a memory error detector
==12566== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==12566== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==12566== Command: ./a.out
==12566==
Init 0x41c7a58
m_test = 4
==12566== Conditional jump or move depends on uninitialised value(s)
==12566== at 0x465C6B0C: vfprintf (in /usr/lib/libc-2.21.so)
==12566== by 0x465CF455: printf (in /usr/lib/libc-2.21.so)
==12566== by 0x8048630: Test::test11() (in /tmp/a.out)
==12566== by 0x8048696: Test::init() (in /tmp/a.out)
==12566== by 0x80484F3: main (in /tmp/a.out)
==12566==
Calling test11 (nil)
==12566== Conditional jump or move depends on uninitialised value(s)
==12566== at 0x465C6B0C: vfprintf (in /usr/lib/libc-2.21.so)
==12566== by 0x465CF455: printf (in /usr/lib/libc-2.21.so)
==12566== by 0x8048610: ITest2::test21() (in /tmp/a.out)
==12566== by 0x80486C6: Test::init() (in /tmp/a.out)
==12566== by 0x80484F3: main (in /tmp/a.out)
==12566==
Calling test21 (nil)
==12566==
==12566== HEAP SUMMARY:
==12566== in use at exit: 18,956 bytes in 2 blocks
==12566== total heap usage: 2 allocs, 0 frees, 18,956 bytes allocated
==12566==
==12566== LEAK SUMMARY:
==12566== definitely lost: 12 bytes in 1 blocks
==12566== indirectly lost: 0 bytes in 0 blocks
==12566== possibly lost: 0 bytes in 0 blocks
==12566== still reachable: 18,944 bytes in 1 blocks
==12566== suppressed: 0 bytes in 0 blocks
==12566== Rerun with --leak-check=full to see details of leaked memory
==12566==
==12566== For counts of detected and suppressed errors, rerun with: -v
==12566== Use --track-origins=yes to see where uninitialised values come from
==12566== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)
