From 3d4bb2b95423927e0d38266fad28ecdf9658a484 Mon Sep 17 00:00:00 2001
From: Axel Naumann <Axel.Naumann@cern.ch>
Date: Mon, 22 Jun 2015 15:18:05 +0200
Subject: [PATCH] Fix fwd-decl detection and loops.

---
 lib/Interpreter/AutoloadCallback.cpp | 57 ++++++++++++++--------------
 1 file changed, 29 insertions(+), 28 deletions(-)

diff --git a/lib/Interpreter/AutoloadCallback.cpp b/lib/Interpreter/AutoloadCallback.cpp
index 0066553b..42597ab6 100644
--- a/lib/Interpreter/AutoloadCallback.cpp
+++ b/lib/Interpreter/AutoloadCallback.cpp
@@ -255,35 +255,36 @@ namespace cling {
     if (T.decls_begin()->m_DGR.isNull())
       return;
 
-    if (const NamedDecl* ND = dyn_cast<NamedDecl>(*T.decls_begin()->m_DGR.begin()))
-      if (ND->getIdentifier() && ND->getName().equals("__Cling_Autoloading_Map")) {
-        AutoloadingVisitor defaultArgsStateCollector;
-        Preprocessor& PP = m_Interpreter->getCI()->getPreprocessor();
-        for (Transaction::const_iterator I = T.decls_begin(), E = T.decls_end();
-             I != E; ++I) {
-          Transaction::DelayCallInfo DCI = *I;
-
-          // if (DCI.m_Call != Transaction::kCCIHandleTopLevelDecl)
-          //   continue;
-          if (DCI.m_DGR.isNull())
-            continue;
-
-          if (const NamedDecl* ND = dyn_cast<NamedDecl>(*T.decls_begin()->m_DGR.begin()))
-            if (ND->getIdentifier()
-                && ND->getName().equals("__Cling_Autoloading_Map")) {
-
-              for (Transaction::const_iterator I = T.decls_begin(),
-                     E = T.decls_end(); I != E; ++I) {
-                Transaction::DelayCallInfo DCI = *I;
-                for (DeclGroupRef::iterator J = DCI.m_DGR.begin(),
-                       JE = DCI.m_DGR.end(); J != JE; ++J) {
-                    defaultArgsStateCollector.TrackDefaultArgStateOf(*J, m_Map, PP);
-                }
-              }
-            }
-
-        }
+    // The first decl must be
+    //   extern int __Cling_Autoloading_Map;
+    bool HaveAutoloadingMapMarker = false;
+    for (auto I = T.decls_begin(), E = T.decls_end();
+         !HaveAutoloadingMapMarker && I != E; ++I) {
+      if (I->m_Call != cling::Transaction::kCCIHandleTopLevelDecl)
+        return;
+      for (auto&& D: I->m_DGR) {
+        if (isa<EmptyDecl>(D))
+          continue;
+        else if (auto VD = dyn_cast<VarDecl>(D)) {
+          HaveAutoloadingMapMarker
+            = VD->hasExternalStorage() && VD->getIdentifier()
+              && VD->getName().equals("__Cling_Autoloading_Map");
+          if (!HaveAutoloadingMapMarker)
+            return;
+          break;
+        } else
+          return;
       }
+    }
+
+    if (!HaveAutoloadingMapMarker)
+      return;
+
+    AutoloadingVisitor defaultArgsStateCollector;
+    Preprocessor& PP = m_Interpreter->getCI()->getPreprocessor();
+    for (auto I = T.decls_begin(), E = T.decls_end(); I != E; ++I)
+      for (auto&& D: I->m_DGR)
+        defaultArgsStateCollector.TrackDefaultArgStateOf(D, m_Map, PP);
   }
 
 } //end namespace cling