Moved rust_allocator_libraries to it's own .bzl file

ffi/rs/BUILD.bazel

@@ -1,7 +1,7 @@
 load("@rules_cc//cc:cc_library.bzl", "cc_library")
 
 # buildifier: disable=bzl-visibility
-load("@rules_rust//rust/private:rust.bzl", "rust_allocator_libraries")
+load("@rules_rust//rust/private:rust_allocator_libraries.bzl", "rust_allocator_libraries")
 
 rust_allocator_libraries(
     name = "allocator_libraries_with_mangling_support",

rust/private/rust.bzl

@@ -20,8 +20,6 @@ load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 load("//rust/private:common.bzl", "COMMON_PROVIDERS", "rust_common")
 load(
     "//rust/private:providers.bzl",
-    "AllocatorLibrariesImplInfo",
-    "AllocatorLibrariesInfo",
     "BuildInfo",
     "CrateGroupInfo",
     "CrateInfo",
@@ -46,6 +44,10 @@ load(
     "transform_deps",
     "transform_sources",
 )
+load(
+    ":rust_allocator_libraries.bzl",
+    "RUSTC_ALLOCATOR_LIBRARIES_ATTRS",
+)
 
 # TODO(marco): Separate each rule into its own file.
 
@@ -650,19 +652,6 @@ RUSTC_ATTRS = {
     ),
 }
 
-# Attributes for rust-based allocator library support.
-# Can't add it directly to RUSTC_ATTRS above, as those are used as
-# aspect parameters and only support simple types ('bool', 'int' or 'string').
-_rustc_allocator_libraries_attrs = {
-    # This is really internal. Not prefixed with `_` since we need to adapt this
-    # in bootstrapping situations, e.g., when building the process wrapper
-    # or allocator libraries themselves.
-    "allocator_libraries": attr.label(
-        default = "//ffi/rs:default_allocator_libraries",
-        providers = [AllocatorLibrariesInfo],
-    ),
-}
-
 _common_attrs = {
     "aliases": attr.label_keyed_string_dict(
         doc = dedent("""\
@@ -836,7 +825,7 @@ _common_attrs = {
         doc = "A setting used to determine whether or not the `--stamp` flag is enabled",
         default = Label("//rust/private:stamp"),
     ),
-} | RUSTC_ATTRS | _rustc_allocator_libraries_attrs
+} | RUSTC_ATTRS | RUSTC_ALLOCATOR_LIBRARIES_ATTRS
 
 _coverage_attrs = {
     "_collect_cc_coverage": attr.label(
@@ -1683,47 +1672,6 @@ rust_library_group = rule(
     """),
 )
 
-def _rust_allocator_libraries_impl(ctx):
-    toolchain = find_toolchain(ctx)
-    allocator_library = ctx.attr.allocator_library[AllocatorLibrariesImplInfo] if ctx.attr.allocator_library else None
-    global_allocator_library = ctx.attr.global_allocator_library[AllocatorLibrariesImplInfo] if ctx.attr.global_allocator_library else None
-
-    make_ccinfo = lambda info, std: toolchain.make_libstd_and_allocator_ccinfo(
-        ctx.label,
-        ctx.actions,
-        struct(allocator_libraries_impl_info = info),
-        std,
-    )
-
-    providers = [AllocatorLibrariesInfo(
-        allocator_library = allocator_library,
-        global_allocator_library = global_allocator_library,
-        libstd_and_allocator_ccinfo = make_ccinfo(allocator_library, "std"),
-        libstd_and_global_allocator_ccinfo = make_ccinfo(global_allocator_library, "std"),
-        nostd_and_global_allocator_ccinfo = make_ccinfo(global_allocator_library, "no_std_with_alloc"),
-    )]
-
-    return providers
-
-rust_allocator_libraries = rule(
-    implementation = _rust_allocator_libraries_impl,
-    provides = [AllocatorLibrariesInfo],
-    attrs = {
-        "allocator_library": attr.label(
-            doc = "An optional library to provide when a default rust allocator is used.",
-            providers = [AllocatorLibrariesImplInfo],
-        ),
-        "global_allocator_library": attr.label(
-            doc = "An optional library to provide when a default rust allocator is used.",
-            providers = [AllocatorLibrariesImplInfo],
-        ),
-    },
-    toolchains = [
-        str(Label("//rust:toolchain_type")),
-        "@bazel_tools//tools/cpp:toolchain_type",
-    ],
-)
-
 def _replace_illlegal_chars(name):
     """Replaces illegal characters in a name with underscores.