Bug 1610678: Add check to clang plugin to raise error when using namespace mozilla::java is present in C++ source; r=andi

Differential Revision: https://phabricator.services.mozilla.com/D60611

--HG--
extra : moz-landing-system : lando

build/clang-plugin/Checks.inc

@@ -25,6 +25,7 @@ CHECK(NoDuplicateRefCntMemberChecker, "no-duplicate-refcnt-member")
 CHECK(NoExplicitMoveConstructorChecker, "no-explicit-move-constructor")
 CHECK(NonMemMovableMemberChecker, "non-memmovable-member")
 CHECK(NonMemMovableTemplateArgChecker, "non-memmovable-template-arg")
+CHECK(NoUsingNamespaceMozillaJavaChecker, "no-using-namespace-mozilla-java")
 CHECK(NonParamInsideFunctionDeclChecker, "non-memmovable-template-arg")
 CHECK(OverrideBaseCallChecker, "override-base-call")
 CHECK(OverrideBaseCallUsageChecker, "override-base-call-usage")

build/clang-plugin/ChecksIncludes.inc

@@ -27,6 +27,7 @@
 #include "NonMemMovableMemberChecker.h"
 #include "NonMemMovableTemplateArgChecker.h"
 #include "NonParamInsideFunctionDeclChecker.h"
+#include "NoUsingNamespaceMozillaJavaChecker.h"
 #include "OverrideBaseCallChecker.h"
 #include "OverrideBaseCallUsageChecker.h"
 #include "ParamTraitsEnumChecker.h"

build/clang-plugin/CustomMatchers.h

@@ -347,6 +347,19 @@ AST_MATCHER(CXXDefaultArgExpr, isNullDefaultArg) {
                                              Expr::NPC_NeverValueDependent);
 }
 
+AST_MATCHER(UsingDirectiveDecl, isUsingNamespaceMozillaJava) {
+  const NamespaceDecl *Namespace = Node.getNominatedNamespace();
+  const std::string &FQName = Namespace->getQualifiedNameAsString();
+
+  static const char NAMESPACE[] = "mozilla::java";
+  static const char PREFIX[] = "mozilla::java::";
+
+  // We match both the `mozilla::java` namespace itself as well as any other
+  // namespaces contained within the `mozilla::java` namespace.
+  return !FQName.compare(NAMESPACE) ||
+         !FQName.compare(0, sizeof(PREFIX) - 1, PREFIX);
+}
+
 } // namespace ast_matchers
 } // namespace clang
 

build/clang-plugin/NoUsingNamespaceMozillaJavaChecker.cpp

@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "NoUsingNamespaceMozillaJavaChecker.h"
+#include "CustomMatchers.h"
+
+void NoUsingNamespaceMozillaJavaChecker::registerMatchers(MatchFinder *AstMatcher) {
+  AstMatcher->addMatcher(
+      usingDirectiveDecl(isUsingNamespaceMozillaJava()).bind("directive"),
+      this);
+}
+
+void NoUsingNamespaceMozillaJavaChecker::check(
+    const MatchFinder::MatchResult &Result) {
+  const UsingDirectiveDecl *Directive =
+      Result.Nodes.getNodeAs<UsingDirectiveDecl>("directive");
+  const NamespaceDecl *Namespace = Directive->getNominatedNamespace();
+
+  diag(Directive->getUsingLoc(),
+       "using namespace %0 is forbidden",
+       DiagnosticIDs::Error)
+      << Namespace->getQualifiedNameAsString();
+}
+

build/clang-plugin/NoUsingNamespaceMozillaJavaChecker.h

@@ -0,0 +1,20 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NoUsingNamespaceMozillaJavaChecker_h__
+#define NoUsingNamespaceMozillaJavaChecker_h__
+
+#include "plugin.h"
+
+class NoUsingNamespaceMozillaJavaChecker : public BaseCheck {
+public:
+  NoUsingNamespaceMozillaJavaChecker(StringRef CheckName,
+                                 ContextType *Context = nullptr)
+      : BaseCheck(CheckName, Context) {}
+  void registerMatchers(MatchFinder *AstMatcher) override;
+  void check(const MatchFinder::MatchResult &Result) override;
+};
+
+#endif
+

build/clang-plugin/moz.build

@@ -32,6 +32,7 @@ HOST_SOURCES += [
     'NonMemMovableMemberChecker.cpp',
     'NonMemMovableTemplateArgChecker.cpp',
     'NonParamInsideFunctionDeclChecker.cpp',
+    'NoUsingNamespaceMozillaJavaChecker.cpp',
     'OverrideBaseCallChecker.cpp',
     'OverrideBaseCallUsageChecker.cpp',
     'ParamTraitsEnumChecker.cpp',

build/clang-plugin/tests/TestNoUsingNamespaceMozillaJava.cpp

@@ -0,0 +1,30 @@
+namespace mozilla {
+namespace java {
+namespace sdk {
+}  // namespace sdk
+
+namespace future {
+}  // namespace future
+}  // namespace java
+}  // namespace mozilla
+
+namespace mozilla {
+  using namespace java;  // expected-error{{using namespace mozilla::java is forbidden}}
+  using namespace java::future;  // expected-error{{using namespace mozilla::java::future is forbidden}}
+}
+
+using namespace mozilla::java::sdk;  // expected-error{{using namespace mozilla::java::sdk is forbidden}}
+
+namespace shouldPass {
+  namespace java {
+  }
+
+  using namespace java;
+}
+
+using namespace shouldPass::java;
+
+
+void test() {
+}
+

build/clang-plugin/tests/moz.build

@@ -37,6 +37,7 @@ SOURCES += [
     'TestNonParameterChecker.cpp',
     'TestNonTemporaryClass.cpp',
     'TestNoRefcountedInsideLambdas.cpp',
+    'TestNoUsingNamespaceMozillaJava.cpp',
     'TestOverrideBaseCall.cpp',
     'TestOverrideBaseCallAnnotation.cpp',
     'TestParamTraitsEnum.cpp',