tcwg-llvm-release.sh: Set LLVM release compiler to clang 12.0

This patch introduces a new function in tcwg-llvm-common.sh which
configures LLVM release compiler to latest clang release. This is
currently set to clang 12.0.0.

Change-Id: Idefcb99055b1edf1cbb78847245281efdaf4103f

2 files changed, 40 insertions, 1 deletions

diff --git a/tcwg-llvm-common.sh b/tcwg-llvm-common.sh
index f410efe6..07755c0e 100755
--- a/tcwg-llvm-common.sh
+++ b/tcwg-llvm-common.sh
@@ -75,6 +75,45 @@ set_compiler () {
   fi
 }
 
+# Set the llvm release compiler to clang 12.0.0
+set_llvm_release_compiler () {
+  local VAL="$1"
+  if [ "${CC+set}" = "set" ] || [ "${CXX+set}" = "set" ]; then
+    echo "ERROR: Duplicating CC/CXX setup"
+    exit 1
+  fi
+
+  if [ "$VAL" = "clang" ]; then
+    release_num=12.0.0
+    case "$(uname -m)" in
+      aarch64)
+        clang_ver=clang+llvm-${release_num}-aarch64-linux-gnu ;;
+      x86_64)
+        clang_ver=clang+llvm-${release_num}-x86_64-linux-gnu-ubuntu-16.04 ;;
+      *)
+        clang_ver=clang+llvm-12.0.0-armv7a-linux-gnueabihf ;;
+    esac
+    cd /usr/local \
+    && wget --progress=dot:giga https://github.com/llvm/llvm-project/releases/download/llvmorg-${release_num}/$clang_ver.tar.xz \
+    && tar xf $clang_ver.tar.xz \
+    && rm $clang_ver.tar.xz
+    release_path=/usr/local/${clang_ver}
+    export CC=$release_path/bin/clang
+    export CXX=$release_path/bin/clang++
+
+    # Starting with clang-11 we need clang's libs in ld.so's search path;
+    # otherwise we get failure to find libc++.so.
+    echo "$release_path/lib" > /etc/ld.so.conf.d/clang.conf
+    ldconfig
+  elif [ "$VAL" = "gcc" ]; then
+    export CC="gcc"
+    export CXX="g++"
+  else
+    echo "ERROR: Unknown compiler '$VAL'"
+    exit 1
+  fi
+}
+
 # Find the closest git hash for the SVN revision
 update_git() {
   local BASE=$1
diff --git a/tcwg-llvm-release.sh b/tcwg-llvm-release.sh
index 0fa9405f..143cbe88 100755
--- a/tcwg-llvm-release.sh
+++ b/tcwg-llvm-release.sh
@@ -102,7 +102,7 @@ while [ "$#" -gt 0 ]; do
         download_toolchain "$WORKSPACE" "$VAL"
         shift ;;
       --compiler)
-        set_compiler "$VAL"
+        set_llvm_release_compiler "$VAL"
         shift ;;
       --toolchain-file)
         if [ "$VAL" != "" ]; then