Add linter to check for keywords in the package name

README.md

@@ -197,10 +197,16 @@ to the element comment. The following lint rules can be suppressed:
 | Lint Rule                   | Containing Lint Groups   | Suppressing Annotation   |
 |-----------------------------|--------------------------|--------------------------|
 | `MESSAGE_FIELDS_NOT_FLOATS` | `uber2`                  | `floats`                 |
+| `PACKAGE_NO_KEYWORDS`       | `uber2`                  | `keywords`               |
 
 As an example:
 
 ```
+// This contains the "public". keyword.
+//
+// @suppresswarnings keywords
+package foo.public.bar;
+
 // Hello is a field where we understand the concerns with using doubles but require them.
 //
 // @suppresswarnings floats
@@ -464,6 +470,8 @@ major version, with some exceptions:
   reflect things such as max line lengths.
 - The breaking change detector may have additional checks added between minor versions, and therefore a change that might not have been
   breaking previously might become a breaking change.
+- The `PACKAGE_NO_KEYWORDS` linter on the `uber2` lint group may have additional keywords added. This can be suppressed by adding
+  `@suppresswarnings keywords` to the package comment.
 
 ## Development
 

internal/cmd/cmd_test.go

@@ -392,10 +392,10 @@ func TestLint(t *testing.T) {
 		t,
 		false,
 		`11:3:FIELDS_NOT_RESERVED
-                 12:3:FIELDS_NOT_RESERVED
-                 14:5:FIELDS_NOT_RESERVED
-                 15:5:FIELDS_NOT_RESERVED
-                 20:5:FIELDS_NOT_RESERVED`,
+		12:3:FIELDS_NOT_RESERVED
+		14:5:FIELDS_NOT_RESERVED
+		15:5:FIELDS_NOT_RESERVED
+		20:5:FIELDS_NOT_RESERVED`,
 		"testdata/lint/noreserved/foo.proto",
 	)
 
@@ -435,6 +435,19 @@ func TestLint(t *testing.T) {
 		"testdata/lint/floats/foo/v1/foo.proto",
 	)
 
+	assertDoLintFile(
+		t,
+		false,
+		`3:1:PACKAGE_NO_KEYWORDS`,
+		"testdata/lint/nokeywords/foo/public/public.proto",
+	)
+	assertDoLintFile(
+		t,
+		false,
+		``,
+		"testdata/lint/nokeywords/foo/public/public_suppressed.proto",
+	)
+
 	assertDoLintFile(
 		t,
 		false,

internal/cmd/testdata/lint/nokeywords/foo/public/public.proto

@@ -0,0 +1,8 @@
+syntax = "proto3";
+
+package foo.public;
+
+option go_package = "publicpb";
+option java_multiple_files = true;
+option java_outer_classname = "PublicProto";
+option java_package = "com.foo.public";

internal/cmd/testdata/lint/nokeywords/foo/public/public_suppressed.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+// @suppresswarnings keywords
+package foo.public;
+
+option go_package = "publicpb";
+option java_multiple_files = true;
+option java_outer_classname = "PublicSuppressedProto";
+option java_package = "com.foo.public";

internal/cmd/testdata/lint/nokeywords/prototool.yaml

@@ -0,0 +1,4 @@
+lint:
+  rules:
+    add:
+      - PACKAGE_NO_KEYWORDS

internal/lint/check_package_no_keywords.go

@@ -0,0 +1,77 @@
+// Copyright (c) 2019 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package lint
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/emicklei/proto"
+	"github.com/uber/prototool/internal/text"
+)
+
+const packageNoKeywordsSuppressableAnnotation = "keywords"
+
+var (
+	packageNoKeywordsKeywords = []string{
+		"internal",  // Golang
+		"public",    // Java, C++, others
+		"private",   // Java, C++, others
+		"protected", // Java, C++, others
+		"std",       // C++ (causes a problem with the std package)
+	}
+
+	packageNoKeywordsLinter = NewLinter(
+		"PACKAGE_NO_KEYWORDS",
+		fmt.Sprintf(`Suppressable with "@suppresswarnings %s". Verifies that no packages contain one of the keywords "%s" as part of the name when split on '.'.`, packageNoKeywordsSuppressableAnnotation, strings.Join(packageNoKeywordsKeywords, ",")),
+		checkPackageNoKeywords,
+	)
+
+	packageNoKeywordsKeywordsMap = make(map[string]struct{}, len(packageNoKeywordsKeywords))
+)
+
+func init() {
+	for _, keyword := range packageNoKeywordsKeywords {
+		packageNoKeywordsKeywordsMap[keyword] = struct{}{}
+	}
+
+}
+
+func checkPackageNoKeywords(add func(*text.Failure), dirPath string, descriptors []*proto.Proto) error {
+	return runVisitor(packageNoKeywordsVisitor{baseAddVisitor: newBaseAddVisitor(add)}, descriptors)
+}
+
+type packageNoKeywordsVisitor struct {
+	baseAddVisitor
+}
+
+func (v packageNoKeywordsVisitor) VisitPackage(pkg *proto.Package) {
+	for _, subPackage := range strings.Split(pkg.Name, ".") {
+		potentialKeyword := strings.ToLower(subPackage)
+		if _, ok := packageNoKeywordsKeywordsMap[potentialKeyword]; ok {
+			if isSuppressed(pkg.Comment, packageNoKeywordsSuppressableAnnotation) {
+				// can just return as this will be true for other keywords as well
+				return
+			}
+			v.AddFailuref(pkg.Position, `Package %q contains the keyword %q, this could cause problems in generated code. This can be suppressed by adding "@suppresswarnings %s" to the package comment.`, pkg.Name, potentialKeyword, packageNoKeywordsSuppressableAnnotation)
+		}
+	}
+}

internal/lint/lint.go

@@ -78,6 +78,7 @@ var (
 		packageIsDeclaredLinter,
 		packageLowerSnakeCaseLinter,
 		packageMajorBetaVersionedLinter,
+		packageNoKeywordsLinter,
 		packagesSameInDirLinter,
 		rpcsHaveCommentsLinter,
 		rpcNamesCamelCaseLinter,
@@ -181,6 +182,7 @@ var (
 		packageIsDeclaredLinter,
 		packageLowerSnakeCaseLinter,
 		packageMajorBetaVersionedLinter,
+		packageNoKeywordsLinter,
 		packagesSameInDirLinter,
 		rpcNamesCamelCaseLinter,
 		rpcNamesCapitalizedLinter,