[ot] scripts/opentitan: run-bazel-tests.sh: Don't clean local overrides

Currently, the `run-bazel-tests.sh` script assumes it is being run from
CI and thus cleans up the local Bazel override files it makes. It is
useful to run it as a developer before making a PR however, but the
current logic would both (a) error upon creating these Bazel override
files if you already had them, and (b) delete them afterwards, breaking
existing OpenTitan integration flows. Add conditional checks to this
logic based on whether these files previously existed to avoid this
behaviour.

Signed-off-by: Alex Jones <[email protected]>

Author: AlexJones0

scripts/opentitan/run-bazel-tests.sh

@@ -45,24 +45,39 @@ if [ ! -x "${qemu_path}/build/qemu-system-riscv32" ]; then
   exit 1
 fi
 
+# Check if needed Bazel repository override files exist
+prev_bazel_files=false
+if [ -f "${qemu_path}/REPO.bazel" ]; then
+  prev_bazel_files=true
+else
+  # Add temporary Bazel `REPO.bazel` file
+  touch "${qemu_path}/REPO.bazel"
+fi
+
+if [ -f "${qemu_path}/BUILD" ]; then
+  prev_bazel_files=true
+else
+  # Add temporary Bazel 'BUILD' file
+  ln -s                                                             \
+    "${opentitan_path}/third_party/qemu/BUILD.qemu_opentitan.bazel" \
+    "${qemu_path}/BUILD"
+fi
+
+
 # Temporary files used by this script:
 results="$(mktemp)"
 flaky="$(mktemp)"
 expected="$(mktemp)"
 all_passed="$(mktemp)"
 passed="$(mktemp)"
 cleanup() {
-  rm -f "${qemu_path}/REPO.bazel" "${qemu_path}/BUILD"
+  if [ "$prev_bazel_files" != "true" ]; then
+    rm -f "${qemu_path}/REPO.bazel" "${qemu_path}/BUILD"
+  fi
   rm -f "$results" "$flaky" "$expected" "$all_passed" "$passed" 
 }
 trap "cleanup" EXIT
 
-## Add temporary `REPO.bazel` and `BUILD` files from Bazel:
-touch "${qemu_path}/REPO.bazel"
-ln -s                                                             \
-  "${opentitan_path}/third_party/qemu/BUILD.qemu_opentitan.bazel" \
-  "${qemu_path}/BUILD"
-
 ## RUN BAZEL TESTS
 cd "$opentitan_path" >/dev/null