Use a parameter file when linking Swift libraries when the host machine is macOS

swift/internal/linking.bzl

@@ -58,7 +58,15 @@ def _register_static_library_link_action(
     )
     args = actions.args()
     args.add_all(command_line)
-    args.add_all(objects)
+
+    filelist_args = actions.args()
+    if swift_toolchain.linker_supports_filelist:
+        args.add("-filelist")
+        filelist_args.set_param_file_format("multiline")
+        filelist_args.use_param_file("%s", use_always = True)
+        filelist_args.add_all(objects)
+    else:
+        args.add_all(objects)
 
     env = cc_common.get_environment_variables(
         action_name = CPP_LINK_STATIC_LIBRARY_ACTION_NAME,
@@ -73,7 +81,7 @@ def _register_static_library_link_action(
     execution_requirements = {req: "1" for req in execution_requirements_list}
 
     actions.run(
-        arguments = [args],
+        arguments = [args, filelist_args],
         env = env,
         executable = archiver_path,
         execution_requirements = execution_requirements,

swift/internal/providers.bzl

@@ -161,6 +161,10 @@ The partial should be called with two arguments:
     or dynamic runtime libraries.
 *   `is_test`: A `Boolean` value indicating whether the target being linked is a
     test target.
+""",
+        "linker_supports_filelist": """\
+`Boolean`. Indicates whether or not the toolchain's linker supports the input
+files passed to it via a file list.
 """,
         "object_format": """\
 `String`. The object file format of the platform that the toolchain is

swift/internal/swift_toolchain.bzl

@@ -168,6 +168,12 @@ def _swift_toolchain_impl(ctx):
         toolchain_root,
     )
 
+    # The static archiver on Linux doesn't currently support the `-filelist`
+    # flag. This should be handled by the C++ toolchain once we migrate away
+    # from invoking the linker directly for static linking.
+    # See https://github.com/bazelbuild/rules_swift/pull/349#issuecomment-550353580.
+    linker_supports_filelist = True if ctx.attr.os == "darwin" else False
+
     # Combine build mode features, autoconfigured features, and required
     # features.
     requested_features = features_for_build_modes(ctx)
@@ -204,6 +210,7 @@ def _swift_toolchain_impl(ctx):
             command_line_copts = ctx.fragments.swift.copts(),
             cpu = ctx.attr.arch,
             linker_opts_producer = linker_opts_producer,
+            linker_supports_filelist = linker_supports_filelist,
             object_format = "elf",
             optional_implicit_deps = [],
             requested_features = requested_features,

swift/internal/xcode_swift_toolchain.bzl

@@ -635,6 +635,7 @@ def _xcode_swift_toolchain_impl(ctx):
             command_line_copts = command_line_copts,
             cpu = cpu,
             linker_opts_producer = linker_opts_producer,
+            linker_supports_filelist = True,
             object_format = "macho",
             optional_implicit_deps = [],
             requested_features = requested_features,