Improved check for trivial templates.

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 "clang/Sema/Sema.h"
@@ skipping 657 matching lines @@
     }
     case Type::Elaborated: {
       CountType(dyn_cast<ElaboratedType>(type)->getNamedType().getTypePtr(),
                 trivial_member,
                 non_trivial_member,
                 templated_non_trivial_member);
       break;
     }
     case Type::Typedef: {
       while (const TypedefType* TT = dyn_cast<TypedefType>(type)) {
-        type = TT->getDecl()->getUnderlyingType().getTypePtr();
+        if (auto* decl = TT->getDecl()) {
+          const std::string name = decl->getNameAsString();
+          if (auto* context = decl->getDeclContext()) {

[dcheng, 2016/11/10 06:58:56]

I've learned that null checking this shouldn't be necessary (since it's not
possible to have a TranslationUnitDecl here).

hans@, how do you feel about not null-checking this?

[hans, 2016/11/10 16:35:36]

I don't think it should be necessary. I don't see how a typedef could be
declared not in a context.

[palmer, 2016/11/10 23:25:58]

Done.

+            if (name == "atomic_int" && context->isStdNamespace()) {
+              (*trivial_member)++;
+              return;
+            }
+          }
+          type = decl->getUnderlyingType().getTypePtr();
+        }
       }
       CountType(type,
                 trivial_member,
                 non_trivial_member,
                 templated_non_trivial_member);
       break;
     }
     default: {
       // Stupid assumption: anything we see that isn't the above is a POD
       // or reference type.
@@ skipping 325 matching lines @@
       }
     } else if (non_reference_type->isPointerType()) {
       non_reference_type = non_reference_type->getPointeeType();
       continue;
     }
     break;
   }
 }
 
 }  // namespace chrome_checker