Bug 1769494 - Exclude xpc from JSHandleRootedTypedefChecker r=andi

XPC also follows SpiderMonkey rule so it should be excluded for now. This will reduce a good amount of warnings.

Differential Revision: https://phabricator.services.mozilla.com/D146497

build/clang-plugin/CustomMatchers.h

@@ -60,6 +60,17 @@ AST_POLYMORPHIC_MATCHER(isFirstParty,
          !ASTIsInSystemHeader(Finder->getASTContext(), Node);
 }
 
+AST_MATCHER(DeclaratorDecl, isNotSpiderMonkey) {
+  // Detect SpiderMonkey path. Not as strict as isFirstParty, but this is
+  // expected to disappear soon by getting a common style guide between DOM and
+  // SpiderMonkey.
+  std::string Path = Node.getBeginLoc().printToString(
+      Finder->getASTContext().getSourceManager());
+  return Path.find("js") == std::string::npos &&
+         Path.find("xpc") == std::string::npos &&
+         Path.find("XPC") == std::string::npos;
+}
+
 /// This matcher will match temporary expressions.
 /// We need this matcher for compatibility with clang 3.* (clang 4 and above
 /// insert a MaterializeTemporaryExpr everywhere).

build/clang-plugin/JSHandleRootedTypedefChecker.cpp

@@ -7,7 +7,8 @@
 
 void JSHandleRootedTypedefChecker::registerMatchers(MatchFinder *AstMatcher) {
   AstMatcher->addMatcher(
-      declaratorDecl(isUsingJSHandleRootedTypedef()).bind("declaratorDecl"),
+      declaratorDecl(isUsingJSHandleRootedTypedef(), isNotSpiderMonkey())
+          .bind("declaratorDecl"),
       this);
 }
 
@@ -29,15 +30,6 @@ void JSHandleRootedTypedefChecker::check(
   const DeclaratorDecl *Declarator =
       Result.Nodes.getNodeAs<DeclaratorDecl>("declaratorDecl");
 
-  // Detect SpiderMonkey path. Admittedly hacky but works
-  bool IsSpiderMonkey = Declarator->getBeginLoc()
-                            .printToString(Result.Context->getSourceManager())
-                            .find("js") != std::string::npos;
-  if (IsSpiderMonkey) {
-    // Using typedefs within SpiderMonkey is okay.
-    return;
-  }
-
   std::string Replacement = getReplacement(Declarator->getType().getAsString());
   diag(Declarator->getBeginLoc(), Warning, DiagnosticIDs::Warning)
       << FixItHint::CreateReplacement(