Wireshark · Wireshark-dev: Re: [Wireshark-dev] Switch to C++11 or C++14

[Luke Mewburn <luke@xxxxxxxxxxx>]

On 18-06-02 11:26, Michał Łabędzki wrote:
  |  C++11 seems to be possible.
  | 
  | Some infos:
  | 1. Wireshark requires at least Qt 5.2.
  | 2. To build Qt5, from 5.7 C++11 is required:
  | http://code.qt.io/cgit/qt/qt5.git/tree/README?h=5.7
  | I assume that building application for Qt 5.7 does not require C++11.
  | 
  | 3. Ubuntu 14.04 LTS supports GCC 4.8.4, Qt  5.2.1  - but LTS End of
  | Life is: April 2019  <-- C++11 is here
  | 4. Ubuntu 16.04 LTS: GCC 5.3.1 , Qt 5.5.1, EOL: April 2021
  | 5. Debian Jessie 8 supports GCC 4.9.2 and Qt 5.3.2, EOL: June 30, 2020
  | 6. RHEL is safe?  Qt 5.6 - 5.11, GCC 4.9.1?

RHEL 6 (CentOS 6) ships with g++ 4.4.7, which does not have
a complete C++11 implementation.

RHEL 7 (CentOS 7) ships with g++ 4.8.5, which has reasonable C++11 support,
although there may be a couple of features missing. I think g++ 4.9
was the first with full C++11 support.

On RHEL, it is possible to install newer versions of g++ using
the "devtoolset" software collections from in the RHEL "SCL" repos; see
- http://softwarecollections.org/
- https://www.softwarecollections.org/en/scls/rhscl/devtoolset-7/

devtoolset-7 has g++ 7.3.1, which supports C++11, C++14 (the default),
and some C++17.


regards,
Luke.


  | http://doc.qt.io/qt-5.6/supported-platforms.html
  | 7. Window, macOS: supports everything :)
  | 8. Fedora 26 (still supported?) has gcc 7.1:
  | https://fedoraproject.org/wiki/Changes/GCC7
  | 9. openSUSE:13.1 gcc 4.9
  | http://download.opensuse.org/distribution/13.2/repo/oss/
  | 10. SLES 12 is also not a problem (C++17?):
  | https://www.suse.com/c/sles-12-toolchain-update-brings-new-developer-tools/
  | 
  | The question is: can we require C++11 right now?
  | 
  | By the way: what is the minimum GCC version for Wireshark. I do not
  | see any check for this in CMakeLists.txt. I assume we check a lot of
  | compilers features instead.
  | pt., 1 cze 2018 o 23:38 Guy Harris <guy@xxxxxxxxxxxx> napisał(a):
  | >
  | > On Jun 1, 2018, at 2:21 PM, Michał Łabędzki <michal.tomasz.labedzki@xxxxxxxxx> wrote:
  | >
  | > > Is there (still) a problem to switch to C++11 or C++14? Petri-Dish seems to support it for Windows, but there is old standard used for Ubuntu.
  | >
  | > GCC C++ standard support:
  | >
  | >         https://gcc.gnu.org/projects/cxx-status.html#cxx11:
  | >
  | >                 "GCC 4.8.1 was the first feature-complete implementation of the 2011 C++ standard, previously known as C++0x."
  | >
  | >         https://gcc.gnu.org/projects/cxx-status.html#cxx14:
  | >
  | >                 "GCC has full support for the previous revision of the C++ standard, which was published in 2014.
  | >
  | >                 This mode is the default in GCC 6.1 and above; it can be explicitly selected with the -std=c++14 command-line flag, or -std=gnu++14 to enable GNU extensions as well."
  | >
  | >                 The table of C++14 features they have shows GCC 5 as the first version to support all the features in the table.
  | >
  | >
  | > Clang C++ standard support:
  | >
  | >         https://clang.llvm.org/cxx_status.html
  | >
  | >                 "Clang 3.3 and later implement all of the ISO C++ 2011 standard."
  | >
  | >                 "Clang 3.4 and later implement all of the ISO C++ 2014 standard."
  | >
  | > I don't have a list of what versions of various Linux distributions, what versions of various *BSDs, and what versions of Xcode supporting what versions of macOS have which versions of GCC and/or Clang, but that would help here in determining what OS versions are required for C++11 or C++14 support.
  | >
  | > This should perhaps go on the "support library version tracking" page, which *already* tracks things other than support libraries, such as CMake:
  | >
  | >         https://wiki.wireshark.org/Development/Support_library_version_tracking
  | >
  | > However, the problem with Ubuntu may be that the compiler in the version of Ubuntu running on the buildbot may be old enough that it doesn't *default* to C++11, so we may have to explicitly *ask* for C++11 in the CMake files.