[libc++] CI: Run -std=c++03 on Clang ToT

[ldionne]

Rebase to trigger CI.

[ldionne]

Print the compiler version for debugging

[ldionne]

Poke CI again -- did the nodes update their Clang ToT yet?

[ldionne]

Poke CI: did the bots update to ToT?

[ldionne]

Poke CI - I think the bots should have updated now.

[ldionne]

@mizvekov For some reason, it looks like the tests are still failing with Clang ToT, even with all your patches applied. Any idea?

We need to fix this for the LLVM 13 release, or users will be unable to compile in C++03 mode (cause libc++ won't work).

[mizvekov]

In D106104#2905786, @ldionne wrote:

@mizvekov For some reason, it looks like the tests are still failing with Clang ToT, even with all your patches applied. Any idea?

We need to fix this for the LLVM 13 release, or users will be unable to compile in C++03 mode (cause libc++ won't work).

It's working on compiler explorer / clang trunk: https://godbolt.org/z/E6xP4qfPa

Maybe that bot has very outdated clang?

[ldionne]

In D106104#2905818, @mizvekov wrote:

In D106104#2905786, @ldionne wrote:

@mizvekov For some reason, it looks like the tests are still failing with Clang ToT, even with all your patches applied. Any idea?

We need to fix this for the LLVM 13 release, or users will be unable to compile in C++03 mode (cause libc++ won't work).

It's working on compiler explorer / clang trunk: https://godbolt.org/z/E6xP4qfPa

Maybe that bot has very outdated clang?

Hmm, interesting, thanks for checking. I think the bots should be updating their image automatically, but perhaps that doesn't work as intended. I'm trying to make them refresh their Docker image here: 496a3815f43d20853a4fad77c7d70414385c3b06

[ldionne]

Poke CI

[ldionne]

Okay, looks like I guessed correctly. The Docker images were being cached and had not updated for a while. Changing the Dockerfile forced them to rebuild and the C++03 job passed. I'll ship this now.

libcxx/utils/ci/Dockerfile

 # Make sure apt-get doesn't try to prompt for stuff like our time zone, etc.
 ENV DEBIAN_FRONTEND=noninteractive
 
 RUN apt-get update && apt-get install -y bash curl
 
 # Install various tools used by the build or the test suite
 RUN apt-get update && apt-get install -y ninja-build python3 python3-sphinx python3-distutils git gdb
 RUN apt-get update && apt-get install -y libc6-dev-i386 # Required to cross-compile to 32 bits
-RUN echo
 
 # Install Clang <latest>, <latest-1> and ToT, which are the ones we support.
 ENV LLVM_LATEST_VERSION=12
 RUN apt-get update && apt-get install -y lsb-release wget software-properties-common
 RUN wget https://apt.llvm.org/llvm.sh -O /tmp/llvm.sh
 RUN bash /tmp/llvm.sh $(($LLVM_LATEST_VERSION - 1)) # previous release
 RUN bash /tmp/llvm.sh $LLVM_LATEST_VERSION          # latest release
 RUN bash /tmp/llvm.sh $(($LLVM_LATEST_VERSION + 1)) # current ToT

libcxx/utils/ci/run-buildbot

check-generated-output)
     # Reject patches that introduce non-ASCII characters or hard tabs.
     # Depends on LC_COLLATE set at the top of this script.
     ! grep -rn '[^ -~]' libcxx/include/ || false
 
     # Reject patches that introduce dependency cycles in the headers.
     python3 libcxx/utils/graph_header_deps.py >/dev/null
 ;;
 generic-cxx03)
-    # TODO: Switch to compiling with Clang ToT once issues with https://reviews.llvm.org/D104500 are resolved.
-    export CC=clang-12
-    export CXX=clang++-12
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx03.cmake" \
                    -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
     check-abi-list
 ;;
 generic-cxx11)
     clean