[Bug c++/85943] New: Template function permits outside access to private variable

[achuah at drwsg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85943

Bug ID: 85943
   Summary: Template function permits outside access to private
variable
   Product: gcc
   Version: 8.1.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: achuah at drwsg dot com
  Target Milestone: ---

This probably should be classified under meta-bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59002

See this example on Godbolt's compiler explorer: https://godbolt.org/g/skvWAt

If the accessing function were not a template function, then GCC correctly
prevents the private access.

If the private member was a function instead of a variable, then GCC correctly
prevents the private access, but only upon instantiation.

Note: in all of these cases, clang will not compile, regardless of whether
there's been an instantiation of the template.

[Bug c++/85943] Template function permits outside access to private variable

[achuah at drwsg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85943

--- Comment #1 from Anthony Chuah  ---
Clarifications:

This bug applies to static variables, not non-static ones.

Please use this example instead: https://godbolt.org/g/LzrzDj

[Bug c++/85943] Template function permits derived class access to private base class static variable

[achuah at drwsg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85943

Anthony Chuah  changed:

   What|Removed |Added

Summary|Template function permits   |Template function permits
   |outside access to private   |derived class access to
   |variable|private base class static
   ||variable

--- Comment #2 from Anthony Chuah  ---
Apologies for yet another edit: next time I'll make sure to have the
fully-written report before submitting.

The issue appears to be that GCC will permit a derived class access to a
private static variable of its base class.

Please use this repro example instead https://godbolt.org/g/A3zCLk, because it
has a listing of different test cases.

[Bug c++/83766] New: Bug 67632 not fixed yet

[achuah at drwsg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83766

Bug ID: 83766
   Summary: Bug 67632 not fixed yet
   Product: gcc
   Version: 6.1.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: achuah at drwsg dot com
  Target Milestone: ---

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67632

I've tested it on gcc 6.1.0, and the same problem is still there. From the bug
tracker it looks like the bug was acknowledged to be an issue, but never
eventually followed up on.

Target: x86_64-linux-gnu
gcc version 6.1.0

[Bug libstdc++/67632] explicit instantiation omits copy constructor and others

[achuah at drwsg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67632

Anthony Chuah  changed:

   What|Removed |Added

 CC||achuah at drwsg dot com

--- Comment #8 from Anthony Chuah  ---
This bug still isn't fixed as of gcc 6.1.0.

[Bug libstdc++/67632] explicit instantiation omits copy constructor and others

[achuah at drwsg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67632

--- Comment #9 from Anthony Chuah  ---
Forgot to add: this bug exists also for clang 5.0.0.

% clang++ -std=c++11 --gcc-toolchain=/path/to/gcc t.o x.cc
/tmp/x-063634.o: In function `copy(std::unordered_map,
std::equal_to, std::allocator > > const&)':
x.cc:(.text+0x18): undefined reference to `std::unordered_map, std::equal_to, std::allocator >
>::unordered_map(std::unordered_map,
std::equal_to, std::allocator > > const&)'
clang-5.0: error: linker command failed with exit code 1 (use -v to see
invocation)