Improve accuracy of detecting type trait fields.

tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp

Index: tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
diff --git a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
index 3a19515c190ac61352db73b703e20e33987e67ac..6be0dd649d67f1cacc0cc6ad9f166e8014e5503c 100644
--- a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
+++ b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
@@ -101,17 +101,6 @@ AST_MATCHER_P(clang::OverloadExpr,
   return true;
 }
 
-bool IsDeclContextInWTF(const clang::DeclContext* decl_context) {
-  auto* namespace_decl = clang::dyn_cast_or_null<clang::NamespaceDecl>(
-      decl_context->getEnclosingNamespaceContext());
-  if (!namespace_decl)
-    return false;
-  if (namespace_decl->getParent()->isTranslationUnit() &&
-      namespace_decl->getName() == "WTF")
-    return true;
-  return IsDeclContextInWTF(namespace_decl->getParent());
-}
-
 template <typename T>
 bool MatchAllOverriddenMethods(
     const clang::CXXMethodDecl& decl,
@@ -453,15 +442,6 @@ bool GetNameForDecl(const clang::VarDecl& decl,
 
   bool is_const = IsProbablyConst(decl, context);
   if (is_const) {
-    // Struct consts in WTF do not become kFoo cuz stuff like type traits
-    // should stay as lowercase.
-    const clang::DeclContext* decl_context = decl.getDeclContext();
-    bool is_in_wtf = IsDeclContextInWTF(decl_context);
-    const clang::CXXRecordDecl* parent =
-        clang::dyn_cast_or_null<clang::CXXRecordDecl>(decl_context);
-    if (is_in_wtf && parent && parent->isStruct())
-      return false;
-
     if (!GetNameForConstant(original_name.str(), name))
       return false;
   } else {
@@ -855,7 +835,14 @@ int main(int argc, const char* argv[]) {
   //   };
   // matches |x|, |y|, and |VALUE|.
   auto field_decl_matcher = id("decl", fieldDecl(in_blink_namespace));
-  auto var_decl_matcher = id("decl", varDecl(in_blink_namespace));
+  auto var_decl_matcher = id(
+      "decl",
+      varDecl(in_blink_namespace,
+              unless(varDecl(  // Unless it is a type trait's static value.

[dcheng, 2016/08/25 03:05:33]

I'd recommend capturing the varDecl(hasName("value", ...) matcher into its own
variable (is_wtf_type_trait_value, perhaps) and then just using it in here.

[Łukasz Anforowicz, 2016/08/25 21:31:41]

Done.

+                  hasName("value"), hasStaticStorageDuration(),

[Łukasz Anforowicz, 2016/08/24 22:36:20]

BTW: All static fields in wtf/TypeTraits.h are named "value".  I assume that
restricting the skipping to fields named "value" is okay, because other things
(e.g. safeToCompareToEmptyOrDeleted that https://crbug.com/598177 talks about)
are not really type traits.

FWIW, the current code results in wtf:wtf_unittests target building fine after
running the renaming tool.

+                  hasType(isConstQualified()), hasType(booleanType()),
+                  hasAncestor(recordDecl(hasAncestor(namespaceDecl(
+                      hasName("WTF"), hasParent(translationUnitDecl())))))))));
   auto enum_member_decl_matcher =
       id("decl", enumConstantDecl(in_blink_namespace));