Package: libstdc++6 Source: gcc-4.9 Version: 4.9.2-10 **********
I believe the fix is to cast from an Ios_Fmtflags to an unsigned type, perform the bit operations, and then cast back to a Ios_Fmtflags before returning it. I recall seeing this one in some Apple headers. Also see http://lists.llvm.org/pipermail/cfe-dev/2015-January/040945.html . ********** $ cat tt.cxx #include <iostream> using namespace std; int main(int argc, char* argv[]) { cout << std::hex << argc << std::dec << argc << endl; return 0; } $ clang++ -fsanitize=undefined tt.cxx -o tt.exe $ ./tt.exe /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/ios_base.h:96:24: runtime error: load of value 4294967221, which is not a valid value for type 'std::_Ios_Fmtflags' /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/ios_base.h:76:67: runtime error: load of value 4294967221, which is not a valid value for type 'std::_Ios_Fmtflags' ... ********** $ apt-cache show libstdc++ Package: libstdc++6 Source: gcc-4.9 Version: 4.9.2-10 Installed-Size: 1319 Maintainer: Debian GCC Maintainers <debian-gcc@lists.debian.org> Architecture: amd64 Replaces: libstdc++6-4.9-dbg (<< 4.9.0-3) Depends: gcc-4.9-base (= 4.9.2-10), libc6 (>= 2.18), libgcc1 (>= 1:4.1.1) Pre-Depends: multiarch-support Conflicts: scim (<< 1.4.2-1) Breaks: gcc-4.3 (<< 4.3.6-1), gcc-4.4 (<< 4.4.6-4), gcc-4.5 (<< 4.5.3-2) Description-en: GNU Standard C++ Library v3 This package contains an additional runtime library for C++ programs built with the GNU compiler. . libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which was included up to g++-2.95. The first version of libstdc++-v3 appeared in g++-3.0. Description-md5: 724ab84919e0e220afb960e36463914d Multi-Arch: same Homepage: http://gcc.gnu.org/ Tag: implemented-in::c++, role::shared-lib Section: libs Priority: important Filename: pool/main/g/gcc-4.9/libstdc++6_4.9.2-10_amd64.deb Size: 272946 MD5sum: 391ae724457378c71fb16fb5d8eb232c SHA1: 234c8593643d0e3bcfd36302f48edeaa4ca01fe5 SHA256: f1509bbabd78e89c861de16931aec5988e1215649688fd4f8dfe1af875a7fbef
