[Bug c++/59816] New: [c++11] Incorrect visibility check in template instantiation when the default constructor is a variadic template.

[Bug c++/59816] New: [c++11] Incorrect visibility check in template instantiation when the default constructor is a variadic template.

[libremax90 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59816

            Bug ID: 59816
           Summary: [c++11] Incorrect visibility check in template
                    instantiation when the default constructor is a
                    variadic template.
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: libremax90 at gmail dot com

The following C++11 code won't compile on GCC 4.8.2 while clang++ will accept
it without a warning. In the following test case, GCC seems to check Base's
default constructor visibility in the test function's context, where the
templates are instantiated.

class Base {
protected:
  template<class... TArgs>
  Base(TArgs...) {}

  // Uncomment to workaround                                                    
  //Base() {}                                                                   
};

class Class
  : public Base {
public:
  template<class... TArgs>
  Class(TArgs... args) : Base { args... } {}

  // Another workaround:                                                        
  //Class() {}                                                                  
};

void test() {
  Class{};
}

Here is `g++ -v`'s output:

Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/4.8.2/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /build/gcc/src/gcc-4.8-20131219/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
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-cloog-backend=isl --disable-cloog-version-check --enable-lto
--enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu
--disable-multilib --disable-werror --enable-checking=release
Thread model: posix
gcc version 4.8.2 20131219 (prerelease) (GCC)

[Bug c++/59816] [c++11] Incorrect visibility check in template instantiation when the default constructor is a variadic template.

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59816

Daniel Krügler <daniel.kruegler at googlemail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |daniel.kruegler@googlemail.
                   |                            |com

--- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> ---
The problem still exists in 4.9.0 20140110 (experimental)
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From: "law at redhat dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/59121] [4.8/4.9 Regression] endless loop with -O2 -floop-parallelize-all
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idY121

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P4
                 CC|                            |law at redhat dot com

--- Comment #10 from Jeffrey A. Law <law at redhat dot com> ---
IMHO, it's high time we move graphite to an unsupported state and closed all
related PRs as WONTFIX.

[Bug c++/59816] [c++11] Incorrect visibility check in template instantiation when the default constructor is a variadic template.

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59816

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> ---
This is fixed for 5.0. I'm adding the testcase and closing the bug.

[Bug c++/59816] [c++11] Incorrect visibility check in template instantiation when the default constructor is a variadic template.

[paolo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59816

--- Comment #3 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> ---
Author: paolo
Date: Wed Mar 18 21:30:04 2015
New Revision: 221502

URL: https://gcc.gnu.org/viewcvs?rev=221502&root=gcc&view=rev
Log:
2015-03-18  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/59816
    * g++.dg/cpp0x/pr59816.C: New.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/pr59816.C
Modified:
    trunk/gcc/testsuite/ChangeLog

[Bug c++/59816] [c++11] Incorrect visibility check in template instantiation when the default constructor is a variadic template.

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59816

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |5.0

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Done.