It took me a long time to whittle this down to a small example, but here it is:
#include <iostream>
#include <deque>
#include <memory>
using std::deque;
using std::auto_ptr;
struct A { long x; char y; A() : x(0) {} };
auto_ptr<deque<A> > foo(int l){
auto_ptr<deque<A> > d(new deque<A>);
A a, b, c;
for (int i=0; i<l; i++)
d->push_back(a);
return d;
}
int main(int argc, char **argv)
{
auto_ptr<deque<A> > d = foo(atoi(argv[1]));
A a, b, c;
for (deque<A>::iterator i = d->begin(); i != d->end(); i++) {
std::cerr << (*i).x << std::endl;
}
return 0;
}
$ /work/external/wwc/bin/g++-3.4.4 -v -save-temps -Wall -fno-strict-aliasing -O2
/work/nova/6067/src/foo.C
Reading specs from
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/specs
Configured with: ../gcc-3.4.4/configure --prefix=/work/external/wwc/prgcc
--program-suffix=-3.4.4 --enable-threads --with-included-gettext
--enable-languages=c,c++,f77 --with-gnu-as
--with-as=/work/external/wwc/prodbinu216/bin/as --with-gnu-ld
--with-ld=/work/external/wwc/prodbinu216/bin/ld : (reconfigured)
../gcc-3.4.4/configure --prefix=/work/external/wwc/prgcc --program-suffix=-3.4.4
--enable-threads --with-included-gettext --enable-languages=c,c++,f77
--with-gnu-as --with-as=/work/external/wwc/prodbinu216/bin/as --with-gnu-ld
--with-ld=/work/external/wwc/prodbinu216/bin/ld
Thread model: posix
gcc version 3.4.4
/work/external/wwc/prgcc/libexec/gcc/sparc-sun-solaris2.8/3.4.4/cc1plus -E
-quiet -v /work/nova/6067/src/foo.C -mcpu=v7 -Wall -fno-strict-aliasing -O2 -o
foo.ii
ignoring nonexistent directory
"/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/../../../../sparc-sun-solaris2.8/include"
#include "..." search starts here:
#include <...> search starts here:
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/../../../../include/c++/3.4.4
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/../../../../include/c++/3.4.4/sparc-sun-solaris2.8
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/../../../../include/c++/3.4.4/backward
/usr/local/include
/work/external/wwc/prgcc/include
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/include
/usr/include
End of search list.
/work/external/wwc/prgcc/libexec/gcc/sparc-sun-solaris2.8/3.4.4/cc1plus
-fpreprocessed foo.ii -quiet -dumpbase foo.C -mcpu=v7 -auxbase foo -O2 -Wall
-version -fno-strict-aliasing -o foo.s
GNU C++ version 3.4.4 (sparc-sun-solaris2.8)
compiled by GNU C version 3.4.4.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
/work/external/wwc/prodbinu216/bin/as --traditional-format -V -Qy -s -xarch=v8
-o foo.o foo.s
GNU assembler version 2.16 (sparc-sun-solaris2.8) using BFD version 2.16
/work/external/wwc/prgcc/libexec/gcc/sparc-sun-solaris2.8/3.4.4/collect2 -V -Y
P,/usr/ccs/lib:/usr/lib -rpath-link /usr/lib -Qy
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/crt1.o
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/crti.o
/usr/ccs/lib/values-Xa.o
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/crtbegin.o
-L/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4 -L/usr/ccs/bin
-L/usr/ccs/lib
-L/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/../../.. foo.o
-lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc -lc
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/crtend.o
/work/external/wwc/prgcc/lib/gcc/sparc-sun-solaris2.8/3.4.4/crtn.o
GNU ld version 2.16
Supported emulations:
elf32_sparc
elf64_sparc
$
If I run this program with the argument greater than 64, it prints out 63 zeros,
followed by the number 513, followed by more zeros. If I run it with the
argument 64, it does the same and then SEGVs.
This is as simple an example as I can produce. The following simplifications
cause the program to behave properly:
1. removing the auto_ptr
2. removing the -fno-strict-aliasing
3. removing any of the unused local variables
4. moving the code from foo() into main
5. making the iterator a const_iterator
6. using -fno-unit-at-a-time
7. replacing -O2 with -O1
Please let me know if you need any more information.
-- David Magerman
[EMAIL PROTECTED]
--
Summary: Corrupted memory with deque of >63 items under gcc-3.4.4
Product: gcc
Version: 3.4.4
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: magerman at rentec dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: sparc-sun-solaris2.8
GCC host triplet: sparc-sun-solaris2.8
GCC target triplet: sparc-sun-solaris2.8
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21939
