Fallback to glob filegroups when missing v2 merkle cache

Author: dzbarsky

MODULE.bazel

@@ -19,7 +19,7 @@ module(
     compatibility_level = 0,
 )
 
-bazel_dep(name = "bazel_features", version = "1.36.0")
+bazel_dep(name = "bazel_features", version = "1.38.0")
 bazel_dep(name = "bazel_skylib", version = "1.5.0")
 bazel_dep(name = "aspect_bazel_lib", version = "2.0.0")
 bazel_dep(name = "rules_cc", version = "0.2.2")

toolchain/BUILD.llvm_repo.tpl

@@ -94,6 +94,18 @@ filegroup(
     ]),
 )
 
+filegroup(
+    name = "lib_legacy",
+    srcs = glob([
+        # Include the .dylib files in the linker sandbox even though they will
+        # not be available at runtime to allow sanitizers to work locally.
+        # Any library linked from the toolchain to be released should be linked statically.
+        "lib/clang/{LLVM_VERSION}/lib/**",
+        "lib/**/libc++*.a",
+        "lib/**/libunwind.a",
+    ]),
+)
+
 filegroup(
     name = "ar",
     srcs = ["bin/llvm-ar"],

toolchain/BUILD.toolchain.tpl

@@ -29,6 +29,12 @@ filegroup(
     visibility = ["//visibility:private"],
 )
 
+filegroup(
+    name = "internal-use-tools-legacy",
+    srcs = glob(["%{tools_dir}/**"]),
+    visibility = ["//visibility:private"],
+)
+
 %{cc_toolchains}
 
 # Convenience targets from the LLVM toolchain.

toolchain/internal/configure.bzl

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@bazel_features//:features.bzl", "bazel_features")
 load("@bazel_skylib//lib:paths.bzl", "paths")
 load(
     "//toolchain:aliases.bzl",
@@ -329,7 +330,7 @@ def _cc_toolchain_str(
             # TODO: Are there other situations where we can continue?
             return ""
 
-    extra_files_str = repr(":internal-use-tools")
+    extra_files_str = repr(":internal-use-tools" if bazel_features.rules.merkle_cache_v2 else ":internal-use-tools-legacy")
 
     # C++ built-in include directories.
     # This contains both the includes shipped with the compiler as well as the sysroot (or host)
@@ -506,7 +507,7 @@ filegroup(name = "strip-files-{suffix}", srcs = [{extra_files_str}])
         template = template + """
 filegroup(
     name = "cxx_builtin_include_files-{suffix}",
-    srcs = ["{llvm_dist_label_prefix}cxx_builtin_include"],
+    srcs = ["{llvm_dist_label_prefix}{cxx_builtin_include_label}"],
 )
 
 filegroup(
@@ -526,7 +527,7 @@ filegroup(
         "{llvm_dist_label_prefix}clang",
         "{llvm_dist_label_prefix}ld",
         "{llvm_dist_label_prefix}ar",
-        "{llvm_dist_label_prefix}lib",
+        "{llvm_dist_label_prefix}{lib_label}",
         ":sysroot-components-{suffix}",
     ],
 )
@@ -629,6 +630,8 @@ cc_toolchain(
         extra_unfiltered_compile_flags = _list_to_string(_dict_value(toolchain_info.extra_unfiltered_compile_flags_dict, target_pair)),
         extra_files_str = extra_files_str,
         cxx_builtin_include_directories = _list_to_string(filtered_cxx_builtin_include_directories),
+        cxx_builtin_include_label = "cxx_builtin_include" if bazel_features.rules.merkle_cache_v2 else "include",
+        lib_label = "lib" if bazel_features.rules.merkle_cache_v2 else "lib_legacy",
         extra_compiler_files = ("\"%s\"," % str(toolchain_info.extra_compiler_files)) if toolchain_info.extra_compiler_files else "",
         major_llvm_version = major_llvm_version,
         extra_exec_compatible_with_specific = toolchain_info.extra_exec_compatible_with.get(target_pair, []),