2 files changed, 32 insertions, 6 deletions
diff --git a/src/libs/cplusplus/LookupContext.cpp b/src/libs/cplusplus/LookupContext.cpp
index 862ff1850e..a844414fc0 100644
--- a/src/libs/cplusplus/LookupContext.cpp
+++ b/src/libs/cplusplus/LookupContext.cpp
@@ -631,10 +631,15 @@ QList<LookupItem> ClassOrNamespace::lookup_helper(const Name *name, bool searchI
                 // a qualified name. For instance, a nested class which is forward declared
                 // in the class but defined outside it - we should capture both.
                 Symbol *match = 0;
+                QSet<ClassOrNamespace *> processed;
                 for (ClassOrNamespace *parentBinding = binding->parent();
                         parentBinding && !match;
-                        parentBinding = parentBinding->parent())
+                        parentBinding = parentBinding->parent()) {
+                    if (processed.contains(parentBinding))
+                        break;
+                    processed.insert(parentBinding);
                     match = parentBinding->lookupInScope(fullName);
+                }
 
                 if (match) {
                     LookupItem item;
@@ -648,8 +653,12 @@ QList<LookupItem> ClassOrNamespace::lookup_helper(const Name *name, bool searchI
         }
 
         QSet<ClassOrNamespace *> processed;
+        QSet<ClassOrNamespace *> processedOwnParents;
         ClassOrNamespace *binding = this;
         do {
+            if (processedOwnParents.contains(binding))
+                break;
+            processedOwnParents.insert(binding);
             lookup_helper(name, binding, &result, &processed, /*templateId = */ 0);
             binding = binding->_parent;
         } while (searchInEnclosingScope && binding);
diff --git a/src/libs/cplusplus/pp-engine.cpp b/src/libs/cplusplus/pp-engine.cpp
index 05a8f66c87..ba8470e50e 100644
--- a/src/libs/cplusplus/pp-engine.cpp
+++ b/src/libs/cplusplus/pp-engine.cpp
@@ -140,6 +140,12 @@ static bool isQtReservedWord(const char *name, int size)
     return false;
 }
 
+static void nestingTooDeep()
+{
+#ifndef NO_DEBUG
+        std::cerr << "*** WARNING #if / #ifdef nesting exceeded the max level " << MAX_LEVEL << std::endl;
+#endif
+}
 
 } // anonymous namespace
 
@@ -1824,6 +1830,12 @@ void Preprocessor::handleIfDirective(PPToken *tk)
     lex(tk); // consume "if" token
     Value result;
     const PPToken lastExpressionToken = evalExpression(tk, result);
+
+    if (m_state.m_ifLevel >= MAX_LEVEL - 1) {
+        nestingTooDeep();
+        return;
+    }
+
     const bool value = !result.is_zero();
 
     const bool wasSkipping = m_state.m_skipping[m_state.m_ifLevel];
@@ -1950,12 +1962,17 @@ void Preprocessor::handleIfDefDirective(bool checkUndefined, PPToken *tk)
             value = !value;
 
         const bool wasSkipping = m_state.m_skipping[m_state.m_ifLevel];
-        ++m_state.m_ifLevel;
-        m_state.m_trueTest[m_state.m_ifLevel] = value;
-        m_state.m_skipping[m_state.m_ifLevel] = wasSkipping ? wasSkipping : !value;
 
-        if (m_client && !wasSkipping && !value)
-            startSkippingBlocks(*tk);
+        if (m_state.m_ifLevel < MAX_LEVEL - 1) {
+            ++m_state.m_ifLevel;
+            m_state.m_trueTest[m_state.m_ifLevel] = value;
+            m_state.m_skipping[m_state.m_ifLevel] = wasSkipping ? wasSkipping : !value;
+
+            if (m_client && !wasSkipping && !value)
+                startSkippingBlocks(*tk);
+        } else {
+            nestingTooDeep();
+        }
 
         lex(tk); // consume the identifier
 #ifndef NO_DEBUG