[Bug c++/58337] New: Mangling of nullptr_t values do not follow ABI

[hstong at ca dot ibm.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58337

            Bug ID: 58337
           Summary: Mangling of nullptr_t values do not follow ABI
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hstong at ca dot ibm.com

The C++ ABI document (available at
http://mentorembedded.github.io/cxx-abi/abi.html#mangle.expr-primary) specifies
a mangling for the nullptr literal.
The mangling that GCC produces is not consistent with the form specified by the
ABI; namely, "LDn0E" is generated by GCC instead of "LDnE".

ICC mangles using the ABI-specified form: "LDnE".

Note that nullptr_t is not an integer type. It is contrary to the specification
to apply the production for integer literals to a literal of type nullptr_t.

### SMALL SOURCE (main.cpp):
typedef decltype(nullptr) NullPtrType;
template <NullPtrType> void foo();
template <> void foo<nullptr>() { }

### ACTUAL MANGLED NAME:
> g++-4.8 -std=c++11 -c main.cpp -o main.o && nm main.o
0000000000000000 T _Z3fooILDn0EEvv

### EXPECTED MANGLED NAME:
_Z3fooILDnEEvv

### g++ -v:
> g++-4.8 -v
Using built-in specs.
COLLECT_GCC=g++-4.8
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
4.8.1-2ubuntu1~12.04' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.8 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-gnu-unique-object --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-4.8-amd64/jre
--enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64 --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 4.8.1 (Ubuntu 4.8.1-2ubuntu1~12.04)