Add protobuf_extra_deps.bzl for loading dependencies necessary for external repositories in protobuf_deps.bzl.

This is needed for `rules_java` which requires additional loads for Bazel 8. This provides a single entrypoint for extra dependencies so we can add these moving forward without breaking users, and is similar to https://github.com/grpc/grpc/blob/master/bazel/grpc_extra_deps.bzl.

Non-bzlmod users should make sure to set the following in their WORKSPACE file:
```
http_archive(
    name = "protobuf",
    strip_prefix = "protobuf-VERSION",
    sha256 = ...,
    url = ...,
)

load("@protobuf//:protobuf_deps.bzl", "protobuf_deps")

protobuf_deps()

load("@protobuf//:protobuf_extra_deps.bzl", "protobuf_extra_deps")

protobuf_extra_deps();
```

PiperOrigin-RevId: 700810708

Author: zhangskz

README.md

@@ -33,6 +33,48 @@ of your project, you should pin to a release commit on a release branch.
 This is because even release branches can experience some instability in between
 release commits.
 
+### Bazel with Bzlmod
+
+Protobuf supports
+[Bzlmod](https://bazel.build/external/module) with Bazel 7 +.
+Users should specify a dependency on protobuf in their MODULE.bazel file as
+follows.
+
+```
+bazel_dep(name = "protobuf", version = <VERSION>)
+```
+
+Users can optionally override the repo name, such as for compatibility with
+WORKSPACE.
+
+```
+bazel_dep(name = "protobuf", version = <VERSION>, repo_name = "com_google_protobuf")
+```
+
+### Bazel with WORKSPACE
+
+Users can also add the following to their legacy
+[WORKSPACE](https://bazel.build/external/overview#workspace-system) file.
+
+Note that the `protobuf_extra_deps.bzl` is added in the `v30.x` release.
+
+```
+http_archive(
+    name = "com_google_protobuf",
+    strip_prefix = "protobuf-VERSION",
+    sha256 = ...,
+    url = ...,
+)
+
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
+
+protobuf_deps()
+
+load("@com_google_protobuf//:protobuf_extra_deps.bzl", "protobuf_extra_deps")
+
+protobuf_extra_deps();
+```
+
 Protobuf Compiler Installation
 ------------------------------
 

WORKSPACE

@@ -3,7 +3,10 @@ workspace(name = "com_google_protobuf")
 # An explicit self-reference to work around changes in Bazel 7.0
 # See https://github.com/bazelbuild/bazel/issues/19973#issuecomment-1787814450
 # buildifier: disable=duplicated-name
-local_repository(name = "com_google_protobuf", path = ".")
+local_repository(
+    name = "com_google_protobuf",
+    path = ".",
+)
 
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
@@ -17,6 +20,10 @@ load("//:protobuf_deps.bzl", "PROTOBUF_MAVEN_ARTIFACTS", "protobuf_deps")
 
 protobuf_deps()
 
+load("//:protobuf_extra_deps.bzl", "protobuf_extra_deps")
+
+protobuf_extra_deps()
+
 load("@rules_python//python:repositories.bzl", "py_repositories")
 
 py_repositories()
@@ -28,19 +35,19 @@ pip_install_dependencies()
 # Bazel platform rules.
 http_archive(
     name = "platforms",
+    sha256 = "3a561c99e7bdbe9173aa653fd579fe849f1d8d67395780ab4770b1f381431d51",
     urls = [
         "https://mirror.bazel.build/github.com/bazelbuild/platforms/releases/download/0.0.7/platforms-0.0.7.tar.gz",
         "https://github.com/bazelbuild/platforms/releases/download/0.0.7/platforms-0.0.7.tar.gz",
     ],
-    sha256 = "3a561c99e7bdbe9173aa653fd579fe849f1d8d67395780ab4770b1f381431d51",
 )
 
 http_archive(
     name = "com_google_googletest",
     sha256 = "7315acb6bf10e99f332c8a43f00d5fbb1ee6ca48c52f6b936991b216c586aaad",
     strip_prefix = "googletest-1.15.0",
     urls = [
-        "https://github.com/google/googletest/releases/download/v1.15.0/googletest-1.15.0.tar.gz" # 2024-07-15
+        "https://github.com/google/googletest/releases/download/v1.15.0/googletest-1.15.0.tar.gz",  # 2024-07-15
     ],
 )
 
@@ -91,12 +98,6 @@ load("@build_bazel_apple_support//lib:repositories.bzl", "apple_support_dependen
 
 apple_support_dependencies()
 
-load("@rules_java//java:repositories.bzl", "rules_java_dependencies", "rules_java_toolchains")
-
-rules_java_dependencies()
-
-rules_java_toolchains()
-
 load("@rules_cc//cc:repositories.bzl", "rules_cc_dependencies")
 
 rules_cc_dependencies()
@@ -112,11 +113,11 @@ kt_register_toolchains()
 
 http_archive(
     name = "rules_ruby",
+    integrity = "sha256-Lh/xxR6WsKJnS92sYkpJDBtdS6DNrCbi0kuUxBffG6E=",
+    strip_prefix = "rules_ruby-588d9dd40487277e2560ece09fe310d7c0ecb4a6",
     urls = [
-      "https://github.com/protocolbuffers/rules_ruby/archive/588d9dd40487277e2560ece09fe310d7c0ecb4a6.zip"
+        "https://github.com/protocolbuffers/rules_ruby/archive/588d9dd40487277e2560ece09fe310d7c0ecb4a6.zip",
     ],
-    strip_prefix = "rules_ruby-588d9dd40487277e2560ece09fe310d7c0ecb4a6",
-    integrity = "sha256-Lh/xxR6WsKJnS92sYkpJDBtdS6DNrCbi0kuUxBffG6E=",
 )
 
 load("@rules_ruby//ruby:defs.bzl", "ruby_runtime")
@@ -157,18 +158,18 @@ http_archive(
 
 http_archive(
     name = "com_github_google_benchmark",
-    urls = ["https://github.com/google/benchmark/archive/0baacde3618ca617da95375e0af13ce1baadea47.zip"],
-    strip_prefix = "benchmark-0baacde3618ca617da95375e0af13ce1baadea47",
     sha256 = "62e2f2e6d8a744d67e4bbc212fcfd06647080de4253c97ad5c6749e09faf2cb0",
+    strip_prefix = "benchmark-0baacde3618ca617da95375e0af13ce1baadea47",
+    urls = ["https://github.com/google/benchmark/archive/0baacde3618ca617da95375e0af13ce1baadea47.zip"],
 )
 
 http_archive(
     name = "com_google_googleapis",
-    urls = ["https://github.com/googleapis/googleapis/archive/d81d0b9e6993d6ab425dff4d7c3d05fb2e59fa57.zip"],
-    strip_prefix = "googleapis-d81d0b9e6993d6ab425dff4d7c3d05fb2e59fa57",
-    sha256 = "d986023c3d8d2e1b161e9361366669cac9fb97c2a07e656c2548aca389248bb4",
     build_file = "//benchmarks:BUILD.googleapis",
     patch_cmds = ["find google -type f -name BUILD.bazel -delete"],
+    sha256 = "d986023c3d8d2e1b161e9361366669cac9fb97c2a07e656c2548aca389248bb4",
+    strip_prefix = "googleapis-d81d0b9e6993d6ab425dff4d7c3d05fb2e59fa57",
+    urls = ["https://github.com/googleapis/googleapis/archive/d81d0b9e6993d6ab425dff4d7c3d05fb2e59fa57.zip"],
 )
 
 load("@system_python//:pip.bzl", "pip_parse")
@@ -184,11 +185,11 @@ install_deps()
 
 http_archive(
     name = "rules_fuzzing",
+    patch_args = ["-p1"],
+    patches = ["//third_party:rules_fuzzing.patch"],
     sha256 = "77206c54b71f4dd5335123a6ff2a8ea688eca5378d34b4838114dff71652cf26",
     strip_prefix = "rules_fuzzing-0.5.1",
     urls = ["https://github.com/bazelbuild/rules_fuzzing/releases/download/v0.5.1/rules_fuzzing-0.5.1.zip"],
-    patches = ["//third_party:rules_fuzzing.patch"],
-    patch_args = ["-p1"],
 )
 
 load("@rules_fuzzing//fuzzing:repositories.bzl", "rules_fuzzing_dependencies")
@@ -214,7 +215,9 @@ load("@rules_rust//rust:repositories.bzl", "rules_rust_dependencies", "rust_regi
 rules_rust_dependencies()
 
 rust_register_toolchains(edition = "2021")
+
 load("@rules_rust//crate_universe:defs.bzl", "crate", "crates_repository")
+
 # to repin, invoke `CARGO_BAZEL_REPIN=1 bazel sync --only=crate_index`
 crates_repository(
     name = "crate_index",
@@ -226,12 +229,13 @@ crates_repository(
             rev = "b407f3b5774defb8917d714bfb7af485e117d621",
         ),
         "paste": crate.spec(
-          version = ">=1",
+            version = ">=1",
         ),
     },
 )
 
 load("@crate_index//:defs.bzl", "crate_repositories")
+
 crate_repositories()
 
 # For testing runtime against old gencode from a previous major version.
@@ -242,11 +246,10 @@ http_archive(
 )
 
 # Needed as a dependency of @com_google_protobuf_v25.0
-load("@com_google_protobuf_v25.0//:protobuf_deps.bzl", protobuf_v25_deps="protobuf_deps")
+load("@com_google_protobuf_v25.0//:protobuf_deps.bzl", protobuf_v25_deps = "protobuf_deps")
+
 protobuf_v25_deps()
 
-# Needed for testing only
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 http_archive(
     name = "rules_testing",
     sha256 = "02c62574631876a4e3b02a1820cb51167bb9cdcdea2381b2fa9d9b8b11c407c4",

examples/WORKSPACE

@@ -41,16 +41,6 @@ load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 
 protobuf_deps()
 
-http_archive(
-    name = "rules_java",
-    sha256 = "9b9614f8a7f7b7ed93cb7975d227ece30fe7daed2c0a76f03a5ee37f69e437de",
-    urls = [
-        "https://github.com/bazelbuild/rules_java/releases/download/8.3.2/rules_java-8.3.2.tar.gz",
-    ],
-)
-
-load("@rules_java//java:repositories.bzl", "rules_java_dependencies", "rules_java_toolchains")
-
-rules_java_dependencies()
+load("@com_google_protobuf//:protobuf_extra_deps.bzl", "protobuf_extra_deps")
 
-rules_java_toolchains()
+protobuf_extra_deps()

protobuf_deps.bzl

@@ -5,15 +5,19 @@ and sets up the repositories protobuf needs:
 
 ```
 http_archive(
-    name = "protobuf",
+    name = "com_google_protobuf",
     strip_prefix = "protobuf-VERSION",
     sha256 = ...,
     url = ...,
 )
 
-load("@protobuf//:protobuf_deps.bzl", "protobuf_deps")
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 
 protobuf_deps()
+
+load("@com_google_protobuf//:protobuf_extra_deps.bzl", "protobuf_extra_deps")
+
+protobuf_extra_deps();
 ```
 """
 

protobuf_extra_deps.bzl

@@ -0,0 +1,31 @@
+"""Loads the dependencies necessary for the external repositories defined in protobuf_deps.bzl.
+
+The consumers should use the following WORKSPACE snippet, which loads dependencies
+and sets up the repositories protobuf needs:
+
+```
+http_archive(
+    name = "com_google_protobuf",
+    strip_prefix = "protobuf-VERSION",
+    sha256 = ...,
+    url = ...,
+)
+
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
+
+protobuf_deps()
+
+load("@com_google_protobuf//:protobuf_extra_deps.bzl", "protobuf_extra_deps")
+
+protobuf_extra_deps();
+```
+"""
+
+load("@rules_java//java:repositories.bzl", "rules_java_dependencies", "rules_java_toolchains")
+
+def protobuf_extra_deps():
+    """Loads extra dependencies needed for the external repositories defined in protobuf_deps.bzl."""
+
+    rules_java_dependencies()
+
+    rules_java_toolchains()