[libc++] CI: Allow pointing to specific dylib roots during backdeploy…

…ment testing

This can be useful when the CI jobs don't have internet access.

libcxx/utils/ci/macos-backdeployment.sh

@@ -4,7 +4,7 @@ set -ue
 
 function usage() {
   cat <<EOM
-$(basename ${0}) [-h|--help] --monorepo-root <MONOREPO-ROOT> --std <STD> --arch <ARCHITECTURE> --deployment-target <TARGET> --sdk-version <SDK-VERSION> [--lit-args <ARGS...>]
+$(basename ${0}) [-h|--help] --monorepo-root <MONOREPO-ROOT> --std <STD> --arch <ARCHITECTURE> --deployment-target <TARGET> --sdk-version <SDK-VERSION> [--libcxx-roots <DIR>] [--lit-args <ARGS...>] [--no-cleanup]
 
 This script is used to continually test the back-deployment use case of libc++ and libc++abi on MacOS.
 
@@ -13,6 +13,7 @@ This script is used to continually test the back-deployment use case of libc++ a
   --arch              Architecture to build the tests for (32, 64).
   --deployment-target The deployment target to run the tests for. This should be a version number of MacOS (e.g. 10.12). All MacOS versions until and including 10.9 are supported.
   --sdk-version       The version of the SDK to test with. This should be a version number of MacOS (e.g. 10.12). We'll link against the libc++ dylib in that SDK, but we'll run against the one on the given deployment target. The SDK version must be no older than the deployment target.
+  [--libcxx-roots]    The path to previous libc++/libc++abi dylibs to use for back-deployment testing. Those are normally downloaded automatically, but if specified, this option will override the directory used. The directory should have the same layout as the roots downloaded automatically.
   [--lit-args]        Additional arguments to pass to lit (optional). If there are multiple arguments, quote them to pass them as a single argument to this script.
   [--no-cleanup]      Do not cleanup the temporary directory that was used for testing at the end. This can be useful to debug failures. Make sure to clean up manually after.
   [-h, --help]        Print this help.
@@ -58,6 +59,10 @@ while [[ $# -gt 0 ]]; do
     ADDITIONAL_LIT_ARGS="${2}"
     shift; shift
     ;;
+    --libcxx-roots)
+    PREVIOUS_DYLIBS_DIR="${2}"
+    shift; shift
+    ;;
     --no-cleanup)
     NO_CLEANUP=""
     shift
@@ -80,6 +85,7 @@ if [[ -z ${ARCH+x} ]]; then echo "--arch is a required parameter"; usage; exit 1
 if [[ -z ${DEPLOYMENT_TARGET+x} ]]; then echo "--deployment-target is a required parameter"; usage; exit 1; fi
 if [[ -z ${MACOS_SDK_VERSION+x} ]]; then echo "--sdk-version is a required parameter"; usage; exit 1; fi
 if [[ -z ${ADDITIONAL_LIT_ARGS+x} ]]; then ADDITIONAL_LIT_ARGS=""; fi
+if [[ -z ${PREVIOUS_DYLIBS_DIR+x} ]]; then PREVIOUS_DYLIBS_DIR=""; fi
 
 if version-less "${MACOS_SDK_VERSION}" "${DEPLOYMENT_TARGET}"; then
   echo "SDK version ${MACOS_SDK_VERSION} shouldn't be older than the deployment target (${DEPLOYMENT_TARGET})"
@@ -134,16 +140,18 @@ ninja -C "${LLVM_BUILD_DIR}" install-cxx-headers
 echo "@@@@@@"
 
 
-echo "@@@ Downloading dylibs for older deployment targets @@@"
 # TODO: We should also link against the libc++abi.dylib that was shipped in the SDK
-PREVIOUS_DYLIBS_DIR="${TEMP_DIR}/libcxx-dylibs"
-mkdir "${PREVIOUS_DYLIBS_DIR}"
-curl "${PREVIOUS_DYLIBS_URL}" | tar -xz --strip-components=1 -C "${PREVIOUS_DYLIBS_DIR}"
+if [[ ${PREVIOUS_DYLIBS_DIR} == "" ]]; then
+  echo "@@@ Downloading dylibs for older deployment targets @@@"
+  PREVIOUS_DYLIBS_DIR="${TEMP_DIR}/libcxx-dylibs"
+  mkdir "${PREVIOUS_DYLIBS_DIR}"
+  curl "${PREVIOUS_DYLIBS_URL}" | tar -xz --strip-components=1 -C "${PREVIOUS_DYLIBS_DIR}"
+  echo "@@@@@@"
+fi
+
 LIBCXX_ON_DEPLOYMENT_TARGET="${PREVIOUS_DYLIBS_DIR}/macOS/${DEPLOYMENT_TARGET}/libc++.dylib"
 LIBCXXABI_ON_DEPLOYMENT_TARGET="${PREVIOUS_DYLIBS_DIR}/macOS/${DEPLOYMENT_TARGET}/libc++abi.dylib"
 LIBCXX_IN_SDK="${PREVIOUS_DYLIBS_DIR}/macOS/${MACOS_SDK_VERSION}/libc++.dylib"
-echo "@@@@@@"
-
 
 # TODO: We need to also run the tests for libc++abi.
 echo "@@@ Running tests for libc++ @@@"