Auto merge of #81451 - nikic:llvm-12, r=nagisa

Upgrade to LLVM 12

This implements the necessary adjustments to make rustc work with LLVM 12. I didn't encounter any major issues so far.

r? `@cuviper`

1 files changed, 34 insertions, 0 deletions

diff --git a/src/ci/docker/scripts/cmake.sh b/src/ci/docker/scripts/cmake.sh
new file mode 100755
index 00000000000..70096173403
--- /dev/null
+++ b/src/ci/docker/scripts/cmake.sh
@@ -0,0 +1,34 @@
+#!/bin/bash
+set -ex
+
+hide_output() {
+  set +x
+  on_err="
+echo ERROR: An error was encountered with the build.
+cat /tmp/build.log
+exit 1
+"
+  trap "$on_err" ERR
+  bash -c "while true; do sleep 30; echo \$(date) - building ...; done" &
+  PING_LOOP_PID=$!
+  "$@" &> /tmp/build.log
+  trap - ERR
+  kill $PING_LOOP_PID
+  rm /tmp/build.log
+  set -x
+}
+
+# LLVM 12 requires CMake 3.13.4 or higher.
+# This script is not necessary for images using Ubuntu 20.04 or newer.
+CMAKE=3.13.4
+curl -L https://github.com/Kitware/CMake/releases/download/v$CMAKE/cmake-$CMAKE.tar.gz | tar xzf -
+
+mkdir cmake-build
+cd cmake-build
+hide_output ../cmake-$CMAKE/configure
+hide_output make -j$(nproc)
+hide_output make install
+
+cd ..
+rm -rf cmake-build
+rm -rf cmake-$CMAKE