feat(gazelle): Gazelle plugin generates py_proto_library

CHANGELOG.md

@@ -91,6 +91,8 @@ END_UNRELEASED_TEMPLATE
 * (gazelle) New directive `gazelle:python_generate_pyi_deps`; when `true`,
   dependencies added to satisfy type-only imports (`if TYPE_CHECKING`) and type
   stub packages are added to `pyi_deps` instead of `deps`.
+* (gazelle) New directive `gazelle:python_generate_proto`; when `true` (by default),
+  Gazelle generates `py_proto_library` rules for `proto_library`.
 
 {#v0-0-0-removed}
 ### Removed

gazelle/README.md

@@ -224,6 +224,8 @@ Python-specific directives are as follows:
 | Controls whether Gazelle resolves dependencies for import statements that use paths relative to the current package. Can be "true" or "false".|
 | `# gazelle:python_generate_pyi_deps`                                                                                                                                                                                                                                                            | `false` |
 | Controls whether to generate a separate `pyi_deps` attribute for type-checking dependencies or merge them into the regular `deps` attribute. When `false` (default), type-checking dependencies are merged into `deps` for backward compatibility. When `true`, generates separate `pyi_deps`. Imports in blocks with the format `if typing.TYPE_CHECKING:`/`if TYPE_CHECKING:` and type-only stub packages (eg. boto3-stubs) are recognized as type-checking dependencies. |
+| `# gazelle:python_generate_proto`                                                                                                                                                                                                                                                            | `true` |
+| Controls whether to generate a `py_proto_library` for each `proto_library` in the package. By default we load this rule from the `@protobuf` repository; use `gazelle:map_kind` if you need to load this from somewhere else. |
 
 #### Directive: `python_root`:
 

gazelle/python/BUILD.bazel

@@ -34,6 +34,7 @@ go_library(
         "@bazel_gazelle//config:go_default_library",
         "@bazel_gazelle//label:go_default_library",
         "@bazel_gazelle//language:go_default_library",
+        "@bazel_gazelle//language/proto:go_default_library",
         "@bazel_gazelle//repo:go_default_library",
         "@bazel_gazelle//resolve:go_default_library",
         "@bazel_gazelle//rule:go_default_library",
@@ -91,7 +92,10 @@ gazelle_test(
 
 gazelle_binary(
     name = "gazelle_binary",
-    languages = [":python"],
+    languages = [
+        "@bazel_gazelle//language/proto",
+        ":python",
+    ],
     visibility = ["//visibility:public"],
 )
 

gazelle/python/configure.go

@@ -70,6 +70,7 @@ func (py *Configurer) KnownDirectives() []string {
 		pythonconfig.LabelNormalization,
 		pythonconfig.GeneratePyiDeps,
 		pythonconfig.ExperimentalAllowRelativeImports,
+		pythonconfig.GenerateProto,
 	}
 }
 
@@ -237,6 +238,12 @@ func (py *Configurer) Configure(c *config.Config, rel string, f *rule.File) {
 				log.Fatal(err)
 			}
 			config.SetGeneratePyiDeps(v)
+		case pythonconfig.GenerateProto:
+			v, err := strconv.ParseBool(strings.TrimSpace(d.Value))
+			if err != nil {
+				log.Fatal(err)
+			}
+			config.SetGenerateProto(v)
 		}
 	}
 

gazelle/python/generate.go

@@ -88,12 +88,20 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 		}
 	}
 
+	var result language.GenerateResult
+	result.Gen = make([]*rule.Rule, 0)
+
+	pythonProjectRoot := cfg.PythonProjectRoot()
+	visibility := cfg.Visibility()
+
+	if cfg.GenerateProto() && args.File != nil {
+		generateProtoLibraries(args, pythonProjectRoot, visibility, &result)
+	}
+
 	actualPyBinaryKind := GetActualKindName(pyBinaryKind, args)
 	actualPyLibraryKind := GetActualKindName(pyLibraryKind, args)
 	actualPyTestKind := GetActualKindName(pyTestKind, args)
 
-	pythonProjectRoot := cfg.PythonProjectRoot()
-
 	packageName := filepath.Base(args.Dir)
 
 	pyLibraryFilenames := treeset.NewWith(godsutils.StringComparator)
@@ -221,10 +229,6 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 	}
 
 	parser := newPython3Parser(args.Config.RepoRoot, args.Rel, cfg.IgnoresDependency)
-	visibility := cfg.Visibility()
-
-	var result language.GenerateResult
-	result.Gen = make([]*rule.Rule, 0)
 
 	collisionErrors := singlylinkedlist.New()
 
@@ -551,3 +555,49 @@ func ensureNoCollision(file *rule.File, targetName, kind string) error {
 	}
 	return nil
 }
+
+func generateProtoLibraries(args language.GenerateArgs, pythonProjectRoot string, visibility []string, res *language.GenerateResult) {
+	// First, enumerate all the proto_library in this package.
+	var protoRuleNames []string
+	for _, r := range args.OtherGen {
+		if r.Kind() != "proto_library" {
+			continue
+		}
+		protoRuleNames = append(protoRuleNames, r.Name())
+	}
+	sort.Strings(protoRuleNames)
+
+	// Next, enumerate all the pre-existing py_proto_library in this package, so we can delete unnecessary rules later.
+	pyProtoRules := map[string]bool{}
+	for _, r := range args.File.Rules {
+		if r.Kind() == "py_proto_library" {
+			pyProtoRules[r.Name()] = false
+		}
+	}
+
+	// Now generate a py_proto_library for each proto_library.
+	emptySiblings := treeset.Set{}
+	for _, protoRuleName := range protoRuleNames {
+		pyProtoLibraryName := protoRuleName + "_py_pb2"
+		pyProtoLibrary := newTargetBuilder(pyProtoLibraryKind, pyProtoLibraryName, pythonProjectRoot, args.Rel, &emptySiblings).
+			addVisibility(visibility).
+			addResolvedDependency(":" + protoRuleName).
+			generateImportsAttribute().build()
+
+		res.Gen = append(res.Gen, pyProtoLibrary)
+		res.Imports = append(res.Imports, pyProtoLibrary.PrivateAttr(config.GazelleImportsKey))
+		pyProtoRules[pyProtoLibrary.Name()] = true
+
+	}
+
+	// Finally, emit an empty rule for each pre-existing py_proto_library that we didn't already generate.
+	for ruleName, generated := range pyProtoRules {
+		if generated {
+			continue
+		}
+
+		emptyRule := newTargetBuilder(pyProtoLibraryKind, ruleName, pythonProjectRoot, args.Rel, &emptySiblings).build()
+		res.Empty = append(res.Empty, emptyRule)
+	}
+
+}

gazelle/python/kinds.go

@@ -19,9 +19,10 @@ import (
 )
 
 const (
-	pyBinaryKind  = "py_binary"
-	pyLibraryKind = "py_library"
-	pyTestKind    = "py_test"
+	pyBinaryKind       = "py_binary"
+	pyLibraryKind      = "py_library"
+	pyProtoLibraryKind = "py_proto_library"
+	pyTestKind         = "py_test"
 )
 
 // Kinds returns a map that maps rule names (kinds) and information on how to
@@ -32,7 +33,7 @@ func (*Python) Kinds() map[string]rule.KindInfo {
 
 var pyKinds = map[string]rule.KindInfo{
 	pyBinaryKind: {
-		MatchAny: false,
+		MatchAny:   false,
 		MatchAttrs: []string{"srcs"},
 		NonEmptyAttrs: map[string]bool{
 			"deps":    true,
@@ -45,7 +46,7 @@ var pyKinds = map[string]rule.KindInfo{
 			"srcs": true,
 		},
 		ResolveAttrs: map[string]bool{
-			"deps": true,
+			"deps":     true,
 			"pyi_deps": true,
 		},
 	},
@@ -62,10 +63,16 @@ var pyKinds = map[string]rule.KindInfo{
 			"srcs": true,
 		},
 		ResolveAttrs: map[string]bool{
-			"deps": true,
+			"deps":     true,
 			"pyi_deps": true,
 		},
 	},
+	pyProtoLibraryKind: {
+		NonEmptyAttrs: map[string]bool{
+			"deps": true,
+		},
+		ResolveAttrs: map[string]bool{"deps": true},
+	},
 	pyTestKind: {
 		MatchAny: false,
 		NonEmptyAttrs: map[string]bool{
@@ -79,7 +86,7 @@ var pyKinds = map[string]rule.KindInfo{
 			"srcs": true,
 		},
 		ResolveAttrs: map[string]bool{
-			"deps": true,
+			"deps":     true,
 			"pyi_deps": true,
 		},
 	},
@@ -101,4 +108,10 @@ var pyLoads = []rule.LoadInfo{
 			pyTestKind,
 		},
 	},
+	{
+		Name: "@protobuf//bazel:py_proto_library.bzl",
+		Symbols: []string{
+			pyProtoLibraryKind,
+		},
+	},
 }

gazelle/python/testdata/directive_python_generate_proto/README.md

@@ -0,0 +1,9 @@
+# Directive: `python_generate_proto`
+
+This test case asserts that the `# gazelle:python_generate_proto` directive
+correctly:
+
+1.  Uses the default value when `python_generate_proto` is not set.
+2.  Generates (or not) `py_proto_library` when `python_generate_proto` is set, based on whether a proto is present.
+
+[gh-2994]: https://github.com/bazel-contrib/rules_python/issues/2994

gazelle/python/testdata/directive_python_generate_proto/WORKSPACE

@@ -0,0 +1 @@
+# This is a Bazel workspace for the Gazelle test data.

gazelle/python/testdata/directive_python_generate_proto/test.yaml

@@ -0,0 +1,17 @@
+# Copyright 2023 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+expect:
+  exit_code: 0

gazelle/python/testdata/directive_python_generate_proto/test1_default_with_proto/BUILD.in

@@ -0,0 +1,10 @@
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# python_generate_proto is not set.
+# nevertheless, py_proto_library is generated.
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/directive_python_generate_proto/test1_default_with_proto/BUILD.out

@@ -0,0 +1,17 @@
+load("@protobuf//bazel:py_proto_library.bzl", "py_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# python_generate_proto is not set.
+# nevertheless, py_proto_library is generated.
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)
+
+py_proto_library(
+    name = "foo_proto_py_pb2",
+    visibility = ["//:__subpackages__"],
+    deps = [":foo_proto"],
+)

gazelle/python/testdata/directive_python_generate_proto/test1_default_with_proto/foo.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package foo;
+
+message Foo {
+    string bar = 1;
+}

gazelle/python/testdata/directive_python_generate_proto/test2_default_without_proto/BUILD.in

@@ -0,0 +1,2 @@
+# python_generate_proto is not set.
+# Since no proto is present, no targets are generated.

gazelle/python/testdata/directive_python_generate_proto/test2_default_without_proto/BUILD.out

@@ -0,0 +1,2 @@
+# python_generate_proto is not set.
+# Since no proto is present, no targets are generated.

gazelle/python/testdata/directive_python_generate_proto/test3_disabled_with_proto/BUILD.in

@@ -0,0 +1,9 @@
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# gazelle:python_generate_proto false
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/directive_python_generate_proto/test3_disabled_with_proto/BUILD.out

@@ -0,0 +1,9 @@
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# gazelle:python_generate_proto false
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/directive_python_generate_proto/test3_disabled_with_proto/foo.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package foo.bar;
+
+message Foo {
+    string bar = 1;
+}

gazelle/python/testdata/directive_python_generate_proto/test4_disabled_without_proto/BUILD.in

@@ -0,0 +1 @@
+# gazelle:python_generate_proto false

gazelle/python/testdata/directive_python_generate_proto/test4_disabled_without_proto/BUILD.out

@@ -0,0 +1 @@
+# gazelle:python_generate_proto false

gazelle/python/testdata/directive_python_generate_proto/test5_enabled_with_proto/BUILD.in

@@ -0,0 +1,9 @@
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# gazelle:python_generate_proto true
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/directive_python_generate_proto/test5_enabled_with_proto/BUILD.out

@@ -0,0 +1,16 @@
+load("@protobuf//bazel:py_proto_library.bzl", "py_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# gazelle:python_generate_proto true
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)
+
+py_proto_library(
+    name = "foo_proto_py_pb2",
+    visibility = ["//:__subpackages__"],
+    deps = [":foo_proto"],
+)

gazelle/python/testdata/directive_python_generate_proto/test5_enabled_with_proto/foo.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package foo;
+
+message Foo {
+    string bar = 1;
+}

gazelle/python/testdata/directive_python_generate_proto/test6_enabled_without_proto/BUILD.in

@@ -0,0 +1 @@
+# gazelle:python_generate_proto true

gazelle/python/testdata/directive_python_generate_proto/test6_enabled_without_proto/BUILD.out

@@ -0,0 +1 @@
+# gazelle:python_generate_proto true

gazelle/python/testdata/directive_python_generate_proto/test7_removes_when_unnecessary/BUILD.in

@@ -0,0 +1,16 @@
+load("@protobuf//bazel:py_proto_library.bzl", "py_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+# gazelle:python_generate_proto true
+
+proto_library(
+    name = "foo_proto",
+    srcs = ["foo.proto"],
+    visibility = ["//:__subpackages__"],
+)
+
+py_proto_library(
+    name = "foo_proto_py_pb2",
+    visibility = ["//:__subpackages__"],
+    deps = [":foo_proto"],
+)

gazelle/python/testdata/directive_python_generate_proto/test7_removes_when_unnecessary/BUILD.out

@@ -0,0 +1 @@
+# gazelle:python_generate_proto true