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 632 matching lines @@
       if (!record_decl->hasDefinition() || record_decl->hasTrivialDestructor())
         (*trivial_member)++;
       else
         (*non_trivial_member)++;
       break;
     }
     case Type::TemplateSpecialization: {
       TemplateName name =
           dyn_cast<TemplateSpecializationType>(type)->getTemplateName();
       bool whitelisted_template = false;
+      bool trivial_template = false;
 
       // HACK: I'm at a loss about how to get the syntax checker to get
       // whether a template is externed or not. For the first pass here,
       // just do simple string comparisons.
       //
       // The check for "atomic_int" is a quick hack; The real fix will be to
       // check the class after template instantiation. TODO(dcheng): Do the real
       // fix. https://bugs.chromium.org/p/chromium/issues/detail?id=663463
       if (TemplateDecl* decl = name.getAsTemplateDecl()) {
         std::string base_name = decl->getNameAsString();
-        if (base_name == "basic_string" || base_name == "atomic_int")
+        if (base_name == "basic_string")
           whitelisted_template = true;
+        else if (base_name == "__atomic_int" || base_name == "atomic_int" ||
+                 base_name == "__atomic_base") {

[dcheng, 2016/11/09 06:33:45]

I'm wondering if we should just intercept this in Type::Typedef: the standard
defines atomic_int to be a typedef for atomic<int>, so it might be more robust
than trying to match against implementation-specified names?

[hans, 2016/11/09 16:48:00]

(Actually, the standard says atomic_int is either a typedef to the
specialization or to a base class of it.)

But yeah, if we could check the name of the typedef that might be better.

[palmer, 2016/11/10 00:25:22]

Done (and that resulted in a smaller diff, which is always nice).

+          trivial_template = true;
+        }
       }
 
-      if (whitelisted_template)
+      if (trivial_template)
+        (*trivial_member)++;
+      else if (whitelisted_template)
         (*non_trivial_member)++;
       else
         (*templated_non_trivial_member)++;
       break;
     }
     case Type::Elaborated: {
       CountType(dyn_cast<ElaboratedType>(type)->getNamedType().getTypePtr(),
                 trivial_member,
                 non_trivial_member,
                 templated_non_trivial_member);
@@ skipping 340 matching lines @@
       }
     } else if (non_reference_type->isPointerType()) {
       non_reference_type = non_reference_type->getPointeeType();
       continue;
     }
     break;
   }
 }
 
 }  // namespace chrome_checker