[Bug libstdc++/65913] New: Linking failure without -latomic

["yan12125 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65913

            Bug ID: 65913
           Summary: Linking failure without -latomic
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: yan12125 at gmail dot com
  Target Milestone: ---

#include <atomic>
#include <iostream>

struct Simple1 { int i; };

int main()
{
    std::atomic<Simple1> s1;
    std::cout << std::boolalpha << s1.is_lock_free() << '\n';
    return 0;
}

On GCC 5.1.0, the following program can't be compiled without -latomic:

g++ -v test.cpp -std=c++11
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /build/gcc-multilib/src/gcc-5.1.0/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 --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --with-default-libstdcxx-abi=c++98
Thread model: posix
gcc version 5.1.0 (GCC) 
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/cc1plus -quiet -v -D_GNU_SOURCE
test.cpp -quiet -dumpbase test.cpp -mtune=generic -march=x86-64 -auxbase test
-std=c++11 -version -o /tmp/ccrpKTDe.s
GNU C++11 (GCC) version 5.1.0 (x86_64-unknown-linux-gnu)
        compiled by GNU C version 5.1.0, GMP version 6.0.0, MPFR version
3.1.2-p11, MPC version 1.0.3
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../x86_64-unknown-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../include/c++/5.1.0

/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../include/c++/5.1.0/x86_64-unknown-linux-gnu

/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../include/c++/5.1.0/backward
 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/include
 /usr/local/include
 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/include-fixed
 /usr/include
End of search list.
GNU C++11 (GCC) version 5.1.0 (x86_64-unknown-linux-gnu)
        compiled by GNU C version 5.1.0, GMP version 6.0.0, MPFR version
3.1.2-p11, MPC version 1.0.3
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 13af7a32108dcf1445ef29e0b81ed4a1
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
 as -v --64 -o /tmp/ccb54wZN.o /tmp/ccrpKTDe.s
GNU assembler version 2.25.0 (x86_64-unknown-linux-gnu) using BFD version (GNU
Binutils) 2.25.0
COMPILER_PATH=/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/:/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/:/usr/lib/gcc/x86_64-unknown-linux-gnu/:/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/:/usr/lib/gcc/x86_64-unknown-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/:/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/collect2 -plugin
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/liblto_plugin.so
-plugin-opt=/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/lto-wrapper
-plugin-opt=-fresolution=/tmp/ccoH7Vln.res -plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --build-id
--eh-frame-hdr --hash-style=gnu -m elf_x86_64 -dynamic-linker
/lib64/ld-linux-x86-64.so.2
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../lib/crt1.o
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../lib/crti.o
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/crtbegin.o
-L/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0
-L/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../..
/tmp/ccb54wZN.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/crtend.o
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.1.0/../../../../lib/crtn.o
/tmp/ccb54wZN.o: In function `std::atomic<Simple1>::is_lock_free() const':
test.cpp:(.text._ZNKSt6atomicI7Simple1E12is_lock_freeEv[_ZNKSt6atomicI7Simple1E12is_lock_freeEv]+0x21):
undefined reference to `__atomic_is_lock_free'
collect2: error: ld returned 1 exit status

Whlie on GCC 4.9.2 of another machine, the program compiles without -latomic:

$ g++ -v test.cpp -std=c++11
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.9.2-10'
--with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.9 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-vtable-verify
--enable-plugin --with-system-zlib --disable-browser-plugin
--enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --with-arch-32=i586 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.9.2 (Debian 4.9.2-10) 
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/4.9/cc1plus -quiet -v -imultiarch
x86_64-linux-gnu -D_GNU_SOURCE test.cpp -quiet -dumpbase test.cpp
-mtune=generic -march=x86-64 -auxbase test -std=c++11 -version -o
/tmp/ccHcMiXf.s
GNU C++ (Debian 4.9.2-10) version 4.9.2 (x86_64-linux-gnu)
        compiled by GNU C version 4.9.2, GMP version 6.0.0, MPFR version
3.1.2-p3, MPC version 1.0.2
warning: MPFR header version 3.1.2-p3 differs from library version 3.1.2-p11.
warning: MPC header version 1.0.2 differs from library version 1.0.3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/4.9"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.9
 /usr/include/x86_64-linux-gnu/c++/4.9
 /usr/include/c++/4.9/backward
 /usr/lib/gcc/x86_64-linux-gnu/4.9/include
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/4.9/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C++ (Debian 4.9.2-10) version 4.9.2 (x86_64-linux-gnu)
        compiled by GNU C version 4.9.2, GMP version 6.0.0, MPFR version
3.1.2-p3, MPC version 1.0.2
warning: MPFR header version 3.1.2-p3 differs from library version 3.1.2-p11.
warning: MPC header version 1.0.2 differs from library version 1.0.3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: ff85870e740eb08c48a56c2c170390f8
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
 as -v --64 -o /tmp/ccAoOSPq.o /tmp/ccHcMiXf.s
GNU assembler version 2.25 (x86_64-linux-gnu) using BFD version (GNU Binutils
for Debian) 2.25
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.9/:/usr/lib/gcc/x86_64-linux-gnu/4.9/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.9/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.9/:/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/4.9/collect2 -plugin
/usr/lib/gcc/x86_64-linux-gnu/4.9/liblto_plugin.so
-plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper
-plugin-opt=-fresolution=/tmp/ccvETIJB.res -plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --sysroot=/
--build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu -dynamic-linker
/lib64/ld-linux-x86-64.so.2
/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crt1.o
/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.9/crtbegin.o
-L/usr/lib/gcc/x86_64-linux-gnu/4.9
-L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu
-L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../../lib -L/lib/x86_64-linux-gnu
-L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib
-L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../.. /tmp/ccAoOSPq.o -lstdc++ -lm
-lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/4.9/crtend.o
/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crtn.o

Is it an incompatible change in libstdc++, or it's a bug? I can't find relevant
reports.