Add support for bzlmod (#1502)

This PR adds initial support for bzlmod. I still have to test it with an
example project, but the basic infrastructure should be ready.

bzlmod is only really ready to be used starting in Bazel 6.0. For this
reason, the `MODULE.bazel` depends on rules_apple 2.0.0, which is also
the release that requires Bazel 6. I will need to first check the newest
version of rules_apple and rules_swift into the Bazel Central Registry,
and then we can proceed testing the rules_xcodeproj integration.

MODULE.bazel

@@ -0,0 +1,22 @@
+module(
+    name = "rules_xcodeproj",
+    version = "0.11.0",
+    repo_name = "com_github_buildbuddy_io_rules_xcodeproj",
+    compatibility_level = 1,
+)
+bazel_dep(name = "bazel_skylib", version = "1.3.0")
+bazel_dep(name = "rules_swift", version = "1.5.1", repo_name = "build_bazel_rules_swift")
+bazel_dep(name = "rules_apple", version = "2.0.0", repo_name = "build_bazel_rules_apple")
+
+non_module_deps = use_extension("//xcodeproj:extensions.bzl", "non_module_deps")
+use_repo(
+    non_module_deps,
+    "rules_xcodeproj_index_import",
+    "com_github_kylef_pathkit",
+    "com_github_tadija_aexml",
+    "com_github_michaeleisel_jjliso8601dateformatter",
+    "com_github_michaeleisel_zippyjsoncfamily",
+    "com_github_michaeleisel_zippyjson",
+    "com_github_tuist_xcodeproj",
+    "com_github_apple_swift_collections",
+)

examples/cc/MODULE.bazel

@@ -0,0 +1,15 @@
+bazel_dep(name = "rules_apple", repo_name = "build_bazel_rules_apple", version = "2.0.0")
+bazel_dep(name = "bazel_skylib", version = "1.3.0")
+bazel_dep(name = "rules_xcodeproj", repo_name = "com_github_buildbuddy_io_rules_xcodeproj", version = "0.0.0")
+bazel_dep(name = "rules_swift", repo_name = "build_bazel_rules_swift", version = "1.5.1")
+bazel_dep(name = "examples_cc_external", version = "0.0.1")
+
+local_path_override(
+    module_name = "rules_xcodeproj",
+    path = "../.."
+)
+
+local_path_override(
+    module_name = "examples_cc_external",
+    path = "external"
+)

examples/cc/external/MODULE.bazel

@@ -0,0 +1,7 @@
+module(
+    name = "examples_cc_external",
+    version = "0.0.1",
+    compatibility_level = 1,
+)
+
+bazel_dep(name = "bazel_skylib", version = "1.3.0")

xcodeproj/extensions.bzl

@@ -0,0 +1,5 @@
+"""Module extension for loading dependencies not yet compatible with bzlmod."""
+
+load("//xcodeproj:repositories.bzl", "xcodeproj_rules_dependencies")
+
+non_module_deps = module_extension(implementation = lambda _: xcodeproj_rules_dependencies(include_bzlmod_ready_dependencies = False))

xcodeproj/repositories.bzl

@@ -51,7 +51,8 @@ pass `ignore_version_differences = True` to `xcodeproj_rules_dependencies()`.
 # buildifier: disable=unnamed-macro
 def xcodeproj_rules_dependencies(
         ignore_version_differences = False,
-        use_dev_patches = False):
+        use_dev_patches = False,
+        include_bzlmod_ready_dependencies = True):
     """Fetches repositories that are dependencies of `rules_xcodeproj`.
 
     Users should call this macro in their `WORKSPACE` to ensure that all of the
@@ -63,22 +64,41 @@ def xcodeproj_rules_dependencies(
             incompatible versions of dependency repositories will be silenced.
         use_dev_patches: If `True`, use patches that are intended to be
             applied to the development version of the repository.
+        include_bzlmod_ready_dependencies: Whether or not bzlmod-ready
+            dependencies should be included.
     """
-    _maybe(
-        http_archive,
-        name = "bazel_skylib",
-        sha256 = "74d544d96f4a5bb630d465ca8bbcfe231e3594e5aae57e1edbf17a6eb3ca2506",
-        url = "https://github.com/bazelbuild/bazel-skylib/releases/download/1.3.0/bazel-skylib-1.3.0.tar.gz",
-        ignore_version_differences = ignore_version_differences,
-    )
+    if include_bzlmod_ready_dependencies:
+        _maybe(
+            http_archive,
+            name = "bazel_skylib",
+            sha256 = "74d544d96f4a5bb630d465ca8bbcfe231e3594e5aae57e1edbf17a6eb3ca2506",
+            url = "https://github.com/bazelbuild/bazel-skylib/releases/download/1.3.0/bazel-skylib-1.3.0.tar.gz",
+            ignore_version_differences = ignore_version_differences,
+        )
 
-    _maybe(
-        http_archive,
-        name = "build_bazel_rules_swift",
-        sha256 = "84e2cc1c9e3593ae2c0aa4c773bceeb63c2d04c02a74a6e30c1961684d235593",
-        url = "https://github.com/bazelbuild/rules_swift/releases/download/1.5.1/rules_swift.1.5.1.tar.gz",
-        ignore_version_differences = ignore_version_differences,
-    )
+        _maybe(
+            http_archive,
+            name = "build_bazel_rules_swift",
+            sha256 = "84e2cc1c9e3593ae2c0aa4c773bceeb63c2d04c02a74a6e30c1961684d235593",
+            url = "https://github.com/bazelbuild/rules_swift/releases/download/1.5.1/rules_swift.1.5.1.tar.gz",
+            ignore_version_differences = ignore_version_differences,
+        )
+
+        is_bazel_6 = hasattr(apple_common, "link_multi_arch_static_library")
+        if is_bazel_6:
+            rules_apple_sha256 = "43737f28a578d8d8d7ab7df2fb80225a6b23b9af9655fcdc66ae38eb2abcf2ed"
+            rules_apple_version = "2.0.0"
+        else:
+            rules_apple_sha256 = "f94e6dddf74739ef5cb30f000e13a2a613f6ebfa5e63588305a71fce8a8a9911"
+            rules_apple_version = "1.1.3"
+
+        _maybe(
+            http_archive,
+            name = "build_bazel_rules_apple",
+            sha256 = rules_apple_sha256,
+            url = "https://github.com/bazelbuild/rules_apple/releases/download/{version}/rules_apple.{version}.tar.gz".format(version = rules_apple_version),
+            ignore_version_differences = ignore_version_differences,
+        )
 
     # `rules_swift` depends on `build_bazel_rules_swift_index_import`, and we
     # also need to use `index-import`, so we could declare the same dependency
@@ -103,22 +123,6 @@ native_binary(
         ignore_version_differences = ignore_version_differences,
     )
 
-    is_bazel_6 = hasattr(apple_common, "link_multi_arch_static_library")
-    if is_bazel_6:
-        rules_apple_sha256 = "43737f28a578d8d8d7ab7df2fb80225a6b23b9af9655fcdc66ae38eb2abcf2ed"
-        rules_apple_version = "2.0.0"
-    else:
-        rules_apple_sha256 = "f94e6dddf74739ef5cb30f000e13a2a613f6ebfa5e63588305a71fce8a8a9911"
-        rules_apple_version = "1.1.3"
-
-    _maybe(
-        http_archive,
-        name = "build_bazel_rules_apple",
-        sha256 = rules_apple_sha256,
-        url = "https://github.com/bazelbuild/rules_apple/releases/download/{version}/rules_apple.{version}.tar.gz".format(version = rules_apple_version),
-        ignore_version_differences = ignore_version_differences,
-    )
-
     _maybe(
         http_archive,
         name = "com_github_kylef_pathkit",