[Bug c++/62126] New: -Wshadow for typedef and template parm

[humbug at deeptown dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62126

            Bug ID: 62126
           Summary: -Wshadow for typedef and template parm
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: humbug at deeptown dot org

$ g++ -v -Wall -Wextra -Wshadow -Wpedantic gcc_shadow.cpp 
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.8/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.8.1-10ubuntu9' --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-i386/jre
--enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-i386
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-i386
--with-arch-directory=i386 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-targets=all --enable-multiarch --disable-werror
--with-arch-32=i686 --with-multilib-list=m32,m64,mx32 --with-tune=generic
--enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu
--target=i686-linux-gnu
Thread model: posix
gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu9) 
COLLECT_GCC_OPTIONS='-v' '-Wall' '-Wextra' '-Wshadow' '-Wpedantic'
'-shared-libgcc' '-mtune=generic' '-march=i686'
 /usr/lib/gcc/i686-linux-gnu/4.8/cc1plus -quiet -v -imultiarch i386-linux-gnu
-D_GNU_SOURCE gcc_shadow.cpp -quiet -dumpbase gcc_shadow.cpp -mtune=generic
-march=i686 -auxbase gcc_shadow -Wall -Wextra -Wshadow -Wpedantic -version
-fstack-protector -Wformat -Wformat-security -o /tmp/ccWvf8WF.s
GNU C++ (Ubuntu/Linaro 4.8.1-10ubuntu9) version 4.8.1 (i686-linux-gnu)
    compiled by GNU C version 4.8.1, GMP version 5.1.2, MPFR version 3.1.1-p2,
MPC version 1.0.1


The following harmful code reports NO warnings:

#include <iostream>

class A
{
public:
    static void hello() {
        std::cerr << "A::hello()" << std::endl;
    }
};

class B
{
public:
    static void hello() {
        std::cerr << "B::hello()" << std::endl;
    }
};

template<typename type>
class Base
{
public:
    typedef type type_t;
    static void hello() {
        typedef int type_t; // <<< shadowing type_t
        type_t x = type_t();
    }
};

template<typename type>
class Derived_typedef : public Base<A>
{
public:
    typedef type type_t; // <<< shadowing Base<A>::type_t
    static void hello() { type_t::hello(); }
};

template<typename type_t>
class Derived_template_param : public Base<A> // <<< shadowing template parm
type_t
{
public:
    static void hello() { type_t::hello(); }
};

int main()
{
    Derived_typedef<B>::hello();
    Derived_template_param<B>::hello();
    return 0;
}