Use ls-remote instead of checkout out the whole repo

Author: oleksandr-pavlyk

.github/workflows/os-llvm-sycl-build.yml

@@ -1,12 +1,12 @@
-name: Build with Open Source LLVM-Sycl compiler
+name: Build with Open Source LLVM SYCL compiler
 on:
   pull_request:
   push:
     branches: [master]
 
 jobs:
   install-compiler:
-    name: Install Nightly build of DPC++ toolchain
+    name: Build with nightly build of DPC++ toolchain
     runs-on: ubuntu-20.04
 
     env:
@@ -39,12 +39,11 @@ jobs:
           cd /home/runner/work
           mkdir -p sycl_bundle
           cd sycl_bundle
-          git clone http://github.com/intel/llvm.git llvm_src
-          cd llvm_src
-          export NIGHTLY_TAG=$(python3 -c "import sys, urllib.parse as ul; print (ul.quote_plus(sys.argv[1]))" $(git tag | sort -V | tail -1))
-          cd ..
+          export LATEST_LLVM_TAG=$(git -c 'versionsort.suffix=-' ls-remote --tags --sort='v:refname' https://github.com/intel/llvm.git | tail --lines=1)
+          export LATEST_LLVM_TAG_SHA=$(echo ${LATEST_LLVM_TAG} | awk '{print $1}')
+          export NIGHTLY_TAG=$(python3 -c "import sys, urllib.parse as ul; print (ul.quote_plus(sys.argv[1]))" $(echo ${LATEST_LLVM_TAG} | awk '{gsub(/^refs\/tags\//, "", $2)} {print $2}'))
           export DOWNLOAD_URL_PREFIX=https://github.com/intel/llvm/releases/download
-          wget ${DOWNLOAD_URL_PREFIX}/${NIGHTLY_TAG}/dpcpp-compiler.tar.gz && echo ${NIGHTLY_TAG} > bundle_id.txt || rm -rf bundle_d.txt
+          wget ${DOWNLOAD_URL_PREFIX}/${NIGHTLY_TAG}/dpcpp-compiler.tar.gz && echo ${LATEST_LLVM_TAG_SHA} > bundle_id.txt || rm -rf bundle_d.txt
           wget ${DOWNLOAD_URL_PREFIX}/2021-07/${OCLCPUEXP_FN}
           wget ${DOWNLOAD_URL_PREFIX}/2021-07/${FPGAEMU_FN}
           wget https://github.com/oneapi-src/oneTBB/releases/download/v2021.4.0/${TBB_FN}