diff --git a/plugins/clang/duchain/builder.cpp b/plugins/clang/duchain/builder.cpp
--- a/plugins/clang/duchain/builder.cpp
+++ b/plugins/clang/duchain/builder.cpp
@@ -946,7 +946,11 @@
 void Visitor::setDeclData(CXCursor cursor, Declaration *decl, bool setComment) const
 {
     if (setComment)
+#if CINDEX_VERSION_MINOR > 100 // FIXME https://bugs.llvm.org/show_bug.cgi?id=35333
         decl->setComment(makeComment(clang_Cursor_getParsedComment(cursor)));
+#else
+        decl->setComment(QByteArray(clang_getCString(clang_Cursor_getRawCommentText(cursor))));
+#endif
     if (CursorKindTraits::isAliasType(CK)) {
         decl->setIsTypeAlias(true);
     }
diff --git a/plugins/clang/duchain/parsesession.cpp b/plugins/clang/duchain/parsesession.cpp
--- a/plugins/clang/duchain/parsesession.cpp
+++ b/plugins/clang/duchain/parsesession.cpp
@@ -70,14 +70,21 @@
     // We remove the -Werror flag, and replace -Werror=foo by -Wfoo.
     // Warning as error may cause problem to the clang parser.
     const auto asError = QByteArrayLiteral("-Werror=");
+    const auto documentation = QByteArrayLiteral("-Wdocumentation");
     for (auto& argument : arguments) {
         if (argument == "-Werror") {
             argument.clear();
         } else if (argument.startsWith(asError)) {
             // replace -Werror=foo by -Wfoo
             argument.remove(2, asError.length() - 2);
         }
+#if CINDEX_VERSION_MINOR < 100 // FIXME https://bugs.llvm.org/show_bug.cgi?id=35333
+        if ( argument == documentation ) {
+            argument.clear();
+        }
+#endif
     }
+
 }
 
 QVector<QByteArray> argsForSession(const QString& path, ParseSessionData::Options options, const ParserSettings& parserSettings)