Enable precompiled protoc toolchain in all repos

mbland · mbland · commit c7d5e1c7ab6d · 2025-03-02T13:41:28.000-05:00
This required importing `@bazel_features` and setting it up so we could
access `@com_google_protobuf//bazel/common/proto_common.bzl`.

Began adding documentation. Haven't tried with Bzlmod yet, but we may
need a way to create targets for users to call `register_toolchains` on.
That, or just expose `@rules_scala_toolchains` as part of the API, which
I've been avoiding.
diff --git a/README.md b/README.md
@@ -62,10 +62,15 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
-# The next two calls instantiate the `@host_platform` repo to work around:
-# - https://github.com/bazelbuild/bazel/issues/22558
 # Only required if using `--incompatible_enable_proto_toolchain_resolution`.
+# Instantiates the `@host_platform` repo to work around:
+# - https://github.com/bazelbuild/bazel/issues/22558
 load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
 
 host_platform_repo(name = "host_platform")
 
@@ -190,6 +195,9 @@ common --incompatible_enable_proto_toolchain_resolution
 
 Set the `protoc_platforms` attribute of `scala_toolchains()` if you need to
 configure protocol compilers for platforms other than the host platform.
+`WORKSPACE` must include the snippet from [Getting started](#getting-started)
+including `register_precompiled_protoc_toolchain()` _before_ any other
+`protobuf` toolchain registrations.
 
 Windows builds now require the precompiled protocol compiler toolchain. See the
 [Windows MSVC builds of protobuf broken by default](#protoc-msvc) section
diff --git a/WORKSPACE b/WORKSPACE
@@ -5,14 +5,15 @@ load("//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
-register_toolchains("@rules_scala_toolchains//protoc/...:all")
-
-# The next two calls instantiate the `@host_platform` repo to work around:
-# - https://github.com/bazelbuild/bazel/issues/22558
 # Only required if using `--incompatible_enable_proto_toolchain_resolution`.
+# Instantiates the `@host_platform` repo to work around:
+# - https://github.com/bazelbuild/bazel/issues/22558
 load("@platforms//host:extension.bzl", "host_platform_repo")
-
 host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
 
 load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")
 
diff --git a/dt_patches/test_dt_patches/WORKSPACE b/dt_patches/test_dt_patches/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/dt_patches/test_dt_patches_user_srcjar/WORKSPACE b/dt_patches/test_dt_patches_user_srcjar/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/crossbuild/WORKSPACE b/examples/crossbuild/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/overridden_artifacts/WORKSPACE b/examples/overridden_artifacts/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/scala3/WORKSPACE b/examples/scala3/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/semanticdb/WORKSPACE b/examples/semanticdb/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/testing/multi_frameworks_toolchain/WORKSPACE b/examples/testing/multi_frameworks_toolchain/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/testing/scalatest_repositories/WORKSPACE b/examples/testing/scalatest_repositories/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/examples/testing/specs2_junit_repositories/WORKSPACE b/examples/testing/specs2_junit_repositories/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/scala/deps.bzl b/scala/deps.bzl
@@ -25,6 +25,14 @@ def rules_scala_dependencies():
         sha256 = "29742e87275809b5e598dc2f04d86960cc7a55b3067d97221c9abbc9926bff0f",
     )
 
+    maybe(
+        http_archive,
+        name = "bazel_features",
+        sha256 = "091d8b1e1f0bf1f7bd688b95007687e862cc489f8d9bc21c14be5fd032a8362f",
+        strip_prefix = "bazel_features-1.26.0",
+        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.26.0/bazel_features-v1.26.0.tar.gz",
+    )
+
     maybe(
         http_archive,
         name = "rules_cc",
@@ -56,8 +64,11 @@ def rules_scala_dependencies():
         sha256 = "008a11cc56f9b96679b4c285fd05f46d317d685be3ab524b2a310be0fbad987e",
         strip_prefix = "protobuf-29.3",
         url = "https://github.com/protocolbuffers/protobuf/archive/refs/tags/v29.3.tar.gz",
-        repo_mapping = {"@com_google_absl": "@abseil-cpp"},
-        patches = ["//patches:0001-protobuf-rm-protoc-dep.patch"],
+        repo_mapping = {
+            "@com_google_absl": "@abseil-cpp",
+            "@proto_bazel_features": "@bazel_features",
+        },
+        patches = [Label("//patches:0001-protobuf-rm-protoc-dep.patch")],
         patch_args = ["-p1"],
     )
 
diff --git a/scala/protoc.bzl b/scala/protoc.bzl
@@ -0,0 +1,6 @@
+"""Precompiled protocol compiler toolchain helpers."""
+load("@com_google_protobuf//bazel/common:proto_common.bzl", "proto_common")
+
+def register_precompiled_protoc_toolchain():
+    if proto_common.INCOMPATIBLE_ENABLE_PROTO_TOOLCHAIN_RESOLUTION:
+        native.register_toolchains("@rules_scala_toolchains//protoc/...:all")
diff --git a/test_cross_build/WORKSPACE b/test_cross_build/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/test_version/WORKSPACE.template b/test_version/WORKSPACE.template
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@platforms//host:extension.bzl", "host_platform_repo")
 
 host_platform_repo(name = "host_platform")
diff --git a/third_party/test/example_external_workspace/WORKSPACE b/third_party/test/example_external_workspace/WORKSPACE
@@ -15,6 +15,14 @@ load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")
 
 rules_java_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@bazel_skylib//:workspace.bzl", "bazel_skylib_workspace")
 
 bazel_skylib_workspace()
diff --git a/third_party/test/proto/WORKSPACE b/third_party/test/proto/WORKSPACE
@@ -11,6 +11,14 @@ load("@rules_scala//scala:deps.bzl", "rules_scala_dependencies")
 
 rules_scala_dependencies()
 
+# For `--incompatible_enable_proto_toolchain_resolution`.
+load("@platforms//host:extension.bzl", "host_platform_repo")
+host_platform_repo(name = "host_platform")
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+bazel_features_deps()
+load("@rules_scala//scala:protoc.bzl", "register_precompiled_protoc_toolchain")
+register_precompiled_protoc_toolchain()
+
 load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")
 
 rules_java_dependencies()
