[llvm-dev] Can we start using std::to_string? (original) (raw)

Pavel Labath via llvm-dev llvm-dev at lists.llvm.org
Mon Nov 6 08:51:13 PST 2017

Hello all,

it took a a bit longer than I hoped, but I am nonetheless pleased to report that our dependency on the version of libstdc++ with broken std::to_string has been removed. The android bot now builds lldb with clang and libc++.

I'm not sure if there are any other obstacles preventing us from using std::to_string, but we are not one of them.

regards, pavel

On 17 May 2017 at 18:34, Tamas Berghammer <tberghammer at google.com> wrote:

The Android NDK currently ships with gcc 4.9.2 what should support std::tostring but there are some issues regarding the implementation of it. The root cause is that complex.h is missing some function from the Android libc (bionic) what results in GLIBCXXUSEC99 not being defined what will disable access to a set of string conversion functions (including std::tostring).

2 relevant bug for the Android NDK: https://github.com/android-ndk/ndk/issues/82 https://issuetracker.google.com/issues/37015480 Tamas On Wed, May 17, 2017 at 2:52 PM 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw> wrote:

Maybe it's time to update the Requirements section on Getting Started with the LLVM System [1]? [1] http://llvm.org/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library 2017-05-17 21:44 GMT+08:00 Hal Finkel via llvm-dev <llvm-dev at lists.llvm.org>:

I'm fairly sure the problem is that we still support building with gcc 4.8.x, and that version of gcc did not have std::tostring. It is not just an NDK issue. -Hal

On 05/17/2017 06:05 AM, Pavel Labath via llvm-dev wrote: Hi Diana, I am responsible for that bot, and probably a great number of those fixups. The root of the problem is that android NDK comes with a libstdc++ which does not have std::tostring. I forgot the exact reason but Dan or Tamas (cc'ed) should know it. The NDK also comes with libc++, which does have working std::tostring, but this one is not compatible with older android devices. This part is being actively worked on though. I am going to sync up with Dan to see if I can give you any timeline on that. And yes, the bot does not build the AVR and other backends, that's why we get no std::string errors there.

On 17 May 2017 at 11:12, Diana Picus via llvm-dev <llvm-dev at lists.llvm.org> wrote: Hi all, I tried to use std::tostring somewhere and one of the bots yelled at me [1] because it couldn't find it. Searching through the mailing lists reveals a long stream of fixup patches trying to avoid std::tostring, but there are uses of it in tree in the AVR and Hexagon backends, libFuzzer and the Gold plugin. I can only imagine they got away with it because the particular bots that can't find std::tostring are probably not building them. Should we fix the bots and remove llvm::tostring? Or is it still too soon? Alternatively, should we replace all uses of std::tostring with llvm::tostring? Cheers, Diana [1] http://lab.llvm.org:8011/builders/lldb-x8664-ubuntu-14.04-buildserver/builds/8853/steps/build%20android/logs/stdio

LLVM Developers mailing list llvm-dev at lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

LLVM Developers mailing list llvm-dev at lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

-- Hal Finkel Lead, Compiler Technology and Programming Languages Leadership Computing Facility Argonne National Laboratory

LLVM Developers mailing list llvm-dev at lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

-- Wei-Ren Chen (陳韋任) Homepage: https://people.cs.nctu.edu.tw/~chenwj

More information about the llvm-dev mailing list