[cfe-dev] -O2 requires GLIBCXX_3.4.9?

[Mohamed Bana]

Hi All,

Why does compiling with -O2 force the resulting binary to require GLIBCXX_3.4.9?

I need to run my binaries on this machine and when I compile with -O0 it seems 
to work fine.

$ uname -a
Linux itrsrh.ldn.itrs 2.6.18-238.9.1.el5 #1 SMP Tue Apr 12 18:10:56 EDT 2011 
i686 i686 i386 GNU/Linux
$ lsb_release -a
LSB Version:    :core-4.0-ia32:core-4.0-noarch:graphics-4.0-ia32:graphics-4.0-
noarch:printing-4.0-ia32:printing-4.0-noarch
Distributor ID: CentOS
Description:    CentOS release 5.6 (Final)
Release:        5.6
Codename:       Final


Any clues?


-Mohamed

Compile Log:

[dev at localhost clang]$ clang++ --version
clang version 3.1 (branches/release_31)
Target: i386-pc-linux-gnu
Thread model: posix
[dev at localhost clang]$ uname -a
Linux localhost.localdomain 2.6.18-308.11.1.el5PAE #1 SMP Tue Jul 10 09:29:33 
EDT 2012 i686 i686 i386 GNU/Linux
[dev at localhost clang]$ lsb_release -a
LSB Version:    :core-4.0-ia32:core-4.0-noarch:graphics-4.0-ia32:graphics-4.0-
noarch:printing-4.0-ia32:printing-4.0-noarch
Distributor ID: CentOS
Description:    CentOS release 5.8 (Final)
Release:        5.8
Codename:       Final
[dev at localhost clang]$ clang++ -O2 -g -faddress-sanitizer -fno-omit-frame-
pointer -fno-inline -fstack-protector-all -fcatch-undefined-behavior -fno-limit-
debug-info test.cpp -o test_opts.o
[dev at localhost clang]$ ldd test_opts.o 
        linux-gate.so.1 =>  (0x00b1e000)
        libstdc++.so.6 => /opt/gcc-4.4.6_install/lib/libstdc++.so.6 (0x002d1000)
        libm.so.6 => /lib/libm.so.6 (0x008e8000)
        libpthread.so.0 => /lib/libpthread.so.0 (0x0092f000)
        libdl.so.2 => /lib/libdl.so.2 (0x00913000)
        libgcc_s.so.1 => /opt/gcc-4.4.6_install/lib/libgcc_s.so.1 (0x0029a000)
        libc.so.6 => /lib/libc.so.6 (0x0078d000)
        /lib/ld-linux.so.2 (0x00769000)
[dev at localhost clang]$ strings test_opts.o | grep GLIBC
GLIBC_2.0
GLIBC_2.2.3
GLIBC_2.2
GLIBCXX_3.4.9
GLIBCXX_3.4.11
GLIBCXX_3.4
GLIBC_2.4
GLIBC_2.1.3
[dev at localhost clang]$ clang++ -O0 -g -faddress-sanitizer -fno-omit-frame-
pointer -fno-inline -fstack-protector-all -fcatch-undefined-behavior -fno-limit-
debug-info test.cpp -o test_no-opt.o
[dev at localhost clang]$ ldd test_no-opt.o 
        linux-gate.so.1 =>  (0x00229000)
        libstdc++.so.6 => /opt/gcc-4.4.6_install/lib/libstdc++.so.6 (0x00791000)
        libm.so.6 => /lib/libm.so.6 (0x008e8000)
        libpthread.so.0 => /lib/libpthread.so.0 (0x0092f000)
        libdl.so.2 => /lib/libdl.so.2 (0x00913000)
        libgcc_s.so.1 => /opt/gcc-4.4.6_install/lib/libgcc_s.so.1 (0x00110000)
        libc.so.6 => /lib/libc.so.6 (0x0022a000)
        /lib/ld-linux.so.2 (0x00769000)
[dev at localhost clang]$ strings test_no-opt.o | grep GLIBC
GLIBC_2.0
GLIBC_2.2.3
GLIBC_2.2
GLIBCXX_3.4
GLIBC_2.4
GLIBC_2.1.3