[Bug c++/67851] New: improve "no unique final overrider" error

[Bug c++/67851] New: improve "no unique final overrider" error

[manu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67851

            Bug ID: 67851
           Summary: improve "no unique final overrider" error
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: manu at gcc dot gnu.org
  Target Milestone: ---

Taken from
http://stackoverflow.com/questions/24006199/virtual-inheritance-error-no-unique-final-overrider

cc1plus:

test.cc:29:7: error: no unique final overrider for ‘virtual void base::fun()’
in ‘der3’
 class der3 : public der1,public der2
       ^

clang++:

38 : error: virtual function 'base::fun' has more than one final overrider in
'der3'
14 : note: overridden virtual function is here
23 : note: final overrider of 'base::fun' in 'der1'
32 : note: final overrider of 'base::fun' in 'der2'


It would be useful if GCC also mentioned which ones are the overriders. In a
complex codebase it could be difficult to figure it out.
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From: "julien.boucaron at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/67852] New: false warning: trigraph reported
Date: Mon, 05 Oct 2015 13:11:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idg852

            Bug ID: 67852
           Summary: false warning: trigraph reported
           Product: gcc
           Version: 5.1.1
            Status: UNCONFIRMED
          Severity: trivial
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: julien.boucaron at gmail dot com
  Target Milestone: ---

False warning reported in this very small thing:

#include <iostream>

int main() {
  std::cout << "test6: BEGIN (PROBLEM HERE???)" << std::endl;
  return 0;
}


Gcc output:

 g++ -Wall -c parser_issue.cc
parser_issue.cc:4:44: warning: trigraph ??) ignored, use -trigraphs to enable
[-Wtrigraphs]
   std::cout << "test6: BEGIN (PROBLEM HERE???)" << std::endl;


Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/5.1.1/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array
--disable-libgcj --with-default-libstdcxx-abi=c++98 --with-isl --enable-libmpx
--enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686
--build=x86_64-redhat-linux
Thread model: posix
gcc version 5.1.1 20150618 (Red Hat 5.1.1-4) (GCC)