Update from https://crrev.com/312398

tools/clang/plugins/FindBadConstructsConsumer.cpp

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "FindBadConstructsConsumer.h"
 
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/AST/Attr.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/Support/raw_ostream.h"
@@ skipping 71 matching lines @@
   // Get the spelling loc just in case it was expanded from a macro.
   SourceRange spelling_range(manager.getSpellingLoc(range.getBegin()));
   // Sanity check that the text looks like virtual.
   StringRef text = clang::Lexer::getSourceText(
       CharSourceRange::getTokenRange(spelling_range), manager, LangOptions());
   if (text.trim() != "virtual")
     return FixItHint();
   return FixItHint::CreateRemoval(range);
 }
 
+bool IsPodOrTemplateType(const CXXRecordDecl& record) {
+  return record.isPOD() ||
+         record.getDescribedClassTemplate() ||
+         record.getTemplateSpecializationKind() ||
+         record.isDependentType();
+}
+
 }  // namespace
 
 FindBadConstructsConsumer::FindBadConstructsConsumer(CompilerInstance& instance,
                                                      const Options& options)
     : ChromeClassTester(instance), options_(options) {
   // Messages for virtual method specifiers.
   diag_method_requires_override_ =
       diagnostic().getCustomDiagID(getErrorLevel(), kMethodRequiresOverride);
   diag_redundant_virtual_specifier_ =
       diagnostic().getCustomDiagID(getErrorLevel(), kRedundantVirtualSpecifier);
@@ skipping 27 matching lines @@
 
 bool FindBadConstructsConsumer::VisitDecl(clang::Decl* decl) {
   clang::TagDecl* tag_decl = dyn_cast<clang::TagDecl>(decl);
   if (tag_decl && tag_decl->isCompleteDefinition())
     CheckTag(tag_decl);
   return true;
 }
 
 void FindBadConstructsConsumer::CheckChromeClass(SourceLocation record_location,
                                                  CXXRecordDecl* record) {
+  // By default, the clang checker doesn't check some types (templates, etc).
+  // That was only a mistake; once Chromium code passes these checks, we should
+  // remove the "check-templates" option and remove this code.
+  // See crbug.com/441916
+  if (!options_.check_templates && IsPodOrTemplateType(*record))
+    return;
+
   bool implementation_file = InImplementationFile(record_location);
 
   if (!implementation_file) {
     // Only check for "heavy" constructors/destructors in header files;
     // within implementation files, there is no performance cost.
-    CheckCtorDtorWeight(record_location, record);
+
+    // If this is a POD or a class template or a type dependent on a
+    // templated class, assume there's no ctor/dtor/virtual method
+    // optimization that we should do.
+    if (!IsPodOrTemplateType(*record))
+      CheckCtorDtorWeight(record_location, record);
   }
 
   bool warn_on_inline_bodies = !implementation_file;
-
   // Check that all virtual methods are annotated with override or final.
-  CheckVirtualMethods(record_location, record, warn_on_inline_bodies);
+  // Note this could also apply to templates, but for some reason Clang
+  // does not always see the "override", so we get false positives.
+  // See http://llvm.org/bugs/show_bug.cgi?id=18440 and
+  //     http://llvm.org/bugs/show_bug.cgi?id=21942
+  if (!IsPodOrTemplateType(*record))
+    CheckVirtualMethods(record_location, record, warn_on_inline_bodies);
 
   CheckRefCountedDtors(record_location, record);
 
-  if (options_.check_weak_ptr_factory_order)
-    CheckWeakPtrFactoryMembers(record_location, record);
+  CheckWeakPtrFactoryMembers(record_location, record);
 }
 
 void FindBadConstructsConsumer::CheckChromeEnum(SourceLocation enum_location,
                                                 EnumDecl* enum_decl) {
   if (!options_.check_enum_last_value)
     return;
 
   bool got_one = false;
   bool is_signed = false;
   llvm::APSInt max_so_far;
@@ skipping 593 matching lines @@
     // one of those, it means there is at least one member after a factory.
     if (weak_ptr_factory_location.isValid() &&
         !param_is_weak_ptr_factory_to_self) {
       diagnostic().Report(weak_ptr_factory_location,
                           diag_weak_ptr_factory_order_);
     }
   }
 }
 
 }  // namespace chrome_checker