http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47072
Summary: exceptions hang in c++ programs compiled by g++-4.5.2
with -O2
Product: gcc
Version: 4.5.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: hbjbb...@yahoo.co.jp
Dear Developers of GCC,
This is a bug report of gcc-4.5.2 (powerpc-apple-darwin9.8.0)
relating with the -O2 optimization.
When the -O2 optimization is used to compile some C++ programs,
exceptions hang forever.
gcc-4.5.2 is natively built from source code on my Macintosh
(PowerBook G4, MacOS X 10.5.8 (Leopard)).
This bug is originally found, when gcc-4.5.2 is used to compile
gmp-5.0.1. In "make check", a C++ program "t-assign" hangs forever.
>From the source code "t-assign.cc", I have prepared a minimal example
program "demo.C" to reproduce the bug in order to write this report.
Please look and see the following log list.
-------------------------------------------------------------------------------
[wisdom3:~/work/425:1] adachi% uname -a
Darwin wisdom3.local 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:57:01 PDT
2009; root:xnu-1228.15.4~1/RELEASE_PPC Power Macintosh
[wisdom3:~/work/425:2] adachi% which g++
/usr/local/bin/g++
[wisdom3:~/work/425:3] adachi% g++ --version
g++ (GCC) 4.5.2
Copyright (C) 2010 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.
[wisdom3:~/work/425:4] adachi% ls
./ ../ demo.C
[wisdom3:~/work/425:5] adachi% cat demo.C
#include <iostream>
#include <stdexcept>
#include <cassert>
int f(int x, int y)
{
std::cout << "Here is in f()." << std::endl;
return -1;
}
class C
{
private:
int x;
public:
C & operator=(int y)
{
if (f(x, y) != 0)
throw std::invalid_argument ("C");
return *this;
}
};
int main(int argc, char** argv)
{
std::cout << "check point <1>" << std::endl;
{
try {
C c;
c = 1;
assert(false); /* should not be reached */
} catch (std::invalid_argument) {
}
}
std::cout << "check point <2>" << std::endl;
{
try {
C c;
c = 2;
assert(false); /* should not be reached */
} catch (std::invalid_argument) {
}
}
std::cout << "check point <3>" << std::endl;
return 0;
}
[wisdom3:~/work/425:6] adachi% g++ demo.C
[wisdom3:~/work/425:7] adachi% ./a.out
check point <1>
Here is in f().
check point <2>
Here is in f().
check point <3>
[wisdom3:~/work/425:8] adachi% rm a.out
remove a.out? y
[wisdom3:~/work/425:9] adachi% g++ -O demo.C
[wisdom3:~/work/425:10] adachi% ./a.out
check point <1>
Here is in f().
check point <2>
Here is in f().
check point <3>
[wisdom3:~/work/425:11] adachi% rm a.out
remove a.out? y
[wisdom3:~/work/425:12] adachi% g++ -O2 demo.C
[wisdom3:~/work/425:13] adachi% ./a.out
check point <1>
Here is in f().
check point <2>
Here is in f().
^C
[wisdom3:~/work/425:14]
-------------------------------------------------------------------------------
As is seen, when "demo.C" is compiled by g++ in gcc-4.5.2
without any optimization or with the "-O" optimization,
the resultant executable "a.out" behaves normally
and no problem occurs.
However, when it is compiled with the "-O2" optimization,
the resultant executable "a.out" hangs forever in its run
and a break "^C" should be typed in shell.
This is a serious bug affecting me and other many users of gcc.
If you kindly fix this bug in some near future,
I and all these users will be very happy.
Sincerely yours,
Satoshi Adachi
