1 files changed, 10 insertions, 1 deletions

diff --git a/contrib/llvm-project/clang/lib/Index/IndexingAction.cpp b/contrib/llvm-project/clang/lib/Index/IndexingAction.cpp
index e698c07133a9..4986303cac47 100644
--- a/contrib/llvm-project/clang/lib/Index/IndexingAction.cpp
+++ b/contrib/llvm-project/clang/lib/Index/IndexingAction.cpp
@@ -165,11 +165,20 @@ static void indexTranslationUnit(ASTUnit &Unit, IndexingContext &IndexCtx) {
 static void indexPreprocessorMacros(const Preprocessor &PP,
                                     IndexDataConsumer &DataConsumer) {
   for (const auto &M : PP.macros())
-    if (MacroDirective *MD = M.second.getLatest())
+    if (MacroDirective *MD = M.second.getLatest()) {
+      auto *MI = MD->getMacroInfo();
+      // When using modules, it may happen that we find #undef of a macro that
+      // was defined in another module. In such case, MI may be nullptr, since
+      // we only look for macro definitions in the current TU. In that case,
+      // there is nothing to index.
+      if (!MI)
+        continue;
+
       DataConsumer.handleMacroOccurrence(
           M.first, MD->getMacroInfo(),
           static_cast<unsigned>(index::SymbolRole::Definition),
           MD->getLocation());
+    }
 }
 
 void index::indexASTUnit(ASTUnit &Unit, IndexDataConsumer &DataConsumer,