blink_gc_plugin: detect singletons with embedded ScriptWrappables.

tools/clang/blink_gc_plugin/CollectVisitor.cpp

Index: tools/clang/blink_gc_plugin/CollectVisitor.cpp
diff --git a/tools/clang/blink_gc_plugin/CollectVisitor.cpp b/tools/clang/blink_gc_plugin/CollectVisitor.cpp
index 203e8adf24427a5fcb196f893feb1737d6caf41a..cae961e0cb9838f3e10e963f5da603c7b26a2154 100644
--- a/tools/clang/blink_gc_plugin/CollectVisitor.cpp
+++ b/tools/clang/blink_gc_plugin/CollectVisitor.cpp
@@ -8,8 +8,8 @@
 
 using namespace clang;
 
-CollectVisitor::CollectVisitor() {
-}
+CollectVisitor::CollectVisitor(bool check_var_decls)
+    : check_var_decls_(check_var_decls), var_visitor_(this) {}
 
 CollectVisitor::RecordVector& CollectVisitor::record_decls() {
   return record_decls_;
@@ -19,6 +19,10 @@ CollectVisitor::MethodVector& CollectVisitor::trace_decls() {
   return trace_decls_;
 }
 
+const CollectVisitor::SingletonVector& CollectVisitor::singleton_decls() const {
+  return singleton_decls_;
+}
+
 bool CollectVisitor::VisitCXXRecordDecl(CXXRecordDecl* record) {
   if (record->hasDefinition() && record->isCompleteDefinition())
     record_decls_.push_back(record);
@@ -30,3 +34,22 @@ bool CollectVisitor::VisitCXXMethodDecl(CXXMethodDecl* method) {
     trace_decls_.push_back(method);
   return true;
 }
+
+bool CollectVisitor::LocalVarsVisitor::VisitVarDecl(VarDecl* decl) {
+  if (Config::IsStaticSingleton(decl) && !Config::IsIgnoreAnnotated(decl) &&
+      decl->isStaticLocal())
+    parent_->singleton_decls_.push_back(decl);
+  return true;
+}
+
+bool CollectVisitor::VisitFunctionDecl(FunctionDecl* decl) {
+  if (!check_var_decls_)
+    return true;
+
+  if (!decl->isThisDeclarationADefinition())
+    return true;
+
+  if (Stmt* body = decl->getBody())
+    var_visitor_.TraverseStmt(body);
+  return true;
+}