[libc++][CI] Adds GCC trunk image.

[mordante]

As discussed during the last monthly meeting we want to be able to test the GCC development version in our CI, but we don't want to commit to support this compiler version.

This adds the image to the CI Docker image. At the moment GCC-15 will not pass the CI. Having it in the Docker image makes it possible to validate fixes.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Mark de Wever (mordante)

Changes

As discussed during the last monthly meeting we want to be able to test the GCC development version in our CI, but we don't want to commit to support this compiler version.

This adds the image to the CI Docker image. At the moment GCC-15 will not pass the CI. Having it in the Docker image makes it possible to validate fixes.

---

Full diff: https://github.com/llvm/llvm-project/pull/132271.diff

2 Files Affected:

• (modified) libcxx/utils/ci/Dockerfile (+14-8)
• (modified) libcxx/utils/ci/docker-compose.yml (+1-1)

diff --git a/libcxx/utils/ci/Dockerfile b/libcxx/utils/ci/Dockerfile
index bd41f288686a4..42e29b301412d 100644
--- a/libcxx/utils/ci/Dockerfile
+++ b/libcxx/utils/ci/Dockerfile
@@ -48,8 +48,8 @@ FROM $BASE_IMAGE AS builder-base
 ENV DEBIAN_FRONTEND=noninteractive
 
 # populated in the docker-compose file
-ARG GCC_LATEST_VERSION
-ENV GCC_LATEST_VERSION=${GCC_LATEST_VERSION}
+ARG GCC_HEAD_VERSION
+ENV GCC_HEAD_VERSION=${GCC_HEAD_VERSION}
 
 # populated in the docker-compose file
 ARG LLVM_HEAD_VERSION
@@ -147,12 +147,18 @@ RUN <<EOF
   set -e
   sudo git clone https://github.com/compiler-explorer/infra.git /tmp/ce-infra
   (cd /tmp/ce-infra && sudo make ce)
-  sudo /tmp/ce-infra/bin/ce_install install compilers/c++/x86/gcc $GCC_LATEST_VERSION.1.0
-  sudo /tmp/ce-infra/bin/ce_install install compilers/c++/x86/gcc $((GCC_LATEST_VERSION - 1)).1.0
-  sudo ln -s /opt/compiler-explorer/gcc-$GCC_LATEST_VERSION.1.0/bin/gcc /usr/bin/gcc-$GCC_LATEST_VERSION
-  sudo ln -s /opt/compiler-explorer/gcc-$GCC_LATEST_VERSION.1.0/bin/g++ /usr/bin/g++-$GCC_LATEST_VERSION
-  sudo ln -s /opt/compiler-explorer/gcc-$((GCC_LATEST_VERSION - 1)).1.0/bin/gcc /usr/bin/gcc-$((GCC_LATEST_VERSION - 1))
-  sudo ln -s /opt/compiler-explorer/gcc-$((GCC_LATEST_VERSION - 1)).1.0/bin/g++ /usr/bin/g++-$((GCC_LATEST_VERSION - 1))
+  # Current ToT, we do not quarantee any support in our support matrix.
+  sudo /tmp/ce-infra/bin/ce_install --enable nightly install compilers/c++/nightly/gcc trunk
+  sudo ln -s /opt/compiler-explorer/gcc-snapshot/bin/gcc /usr/bin/gcc-$GCC_HEAD_VERSION
+  sudo ln -s /opt/compiler-explorer/gcc-snapshot/bin/g++ /usr/bin/g++-$GCC_HEAD_VERSION
+  # The latest release.
+  sudo /tmp/ce-infra/bin/ce_install install compilers/c++/x86/gcc $((GCC_HEAD_VERSION - 1)).1.0
+  sudo ln -s /opt/compiler-explorer/gcc-$((GCC_HEAD_VERSION - 1)).1.0/bin/gcc /usr/bin/gcc-$((GCC_HEAD_VERSION - 1))
+  sudo ln -s /opt/compiler-explorer/gcc-$((GCC_HEAD_VERSION - 1)).1.0/bin/g++ /usr/bin/g++-$((GCC_HEAD_VERSION - 1))
+  # For CI transistions.
+  sudo /tmp/ce-infra/bin/ce_install install compilers/c++/x86/gcc $((GCC_HEAD_VERSION - 2)).1.0
+  sudo ln -s /opt/compiler-explorer/gcc-$((GCC_HEAD_VERSION - 2)).1.0/bin/gcc /usr/bin/gcc-$((GCC_HEAD_VERSION - 2))
+  sudo ln -s /opt/compiler-explorer/gcc-$((GCC_HEAD_VERSION - 2)).1.0/bin/g++ /usr/bin/g++-$((GCC_HEAD_VERSION - 2))
   sudo rm -rf /tmp/ce-infra
 EOF
 
diff --git a/libcxx/utils/ci/docker-compose.yml b/libcxx/utils/ci/docker-compose.yml
index 68e89db5cf452..7e380cd34f47c 100644
--- a/libcxx/utils/ci/docker-compose.yml
+++ b/libcxx/utils/ci/docker-compose.yml
@@ -1,5 +1,5 @@
 x-versions: &compiler_versions
-  GCC_LATEST_VERSION: 14
+  GCC_HEAD_VERSION: 15
   LLVM_HEAD_VERSION: 21
 
 services: