[Bug libmudflap/58232] New: False mudflap positive on std::setw

[andrey.vihrov at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58232

            Bug ID: 58232
           Summary: False mudflap positive on std::setw
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libmudflap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andrey.vihrov at gmail dot com

Created attachment 30694
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30694&action=edit
Preprocessed source

Compiling and running the following code with "g++ -O2 -Wall -Wextra -fmudflap
-lmudflap" seems to produce a false mudflap violation positive:

#include <iostream>
#include <iomanip>

int main()
{
    std::cout << std::setw(6);
}

Program output:
*******
mudflap violation 1 (check/read): time=1377279836.003018 ptr=0x7fec50b2cd00
size=8
pc=0x7fec50b50208 location=`/usr/include/c++/4.8.1/iomanip:237:7 (main)'
      /usr/lib/libmudflap.so.0(__mf_check+0x18) [0x7fec50b50208]
      ./a.out(main+0x8e) [0x400a9e]
      /usr/lib/libc.so.6(__libc_start_main+0xf5) [0x7fec4ffa1bc5]
number of nearby objects: 0

gcc -v is:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/4.8.1/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /build/gcc-multilib/src/gcc-4.8-20130725/configure
--prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared
--enable-threads=posix --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--enable-gnu-unique-object --enable-linker-build-id --enable-cloog-backend=isl
--disable-cloog-version-check --enable-lto --enable-gold --enable-ld=default
--enable-plugin --with-plugin-ld=ld.gold --with-linker-hash-style=gnu
--disable-install-libiberty --enable-multilib --disable-libssp --disable-werror
--enable-checking=release
Thread model: posix
gcc version 4.8.1 20130725 (prerelease) (GCC)