From de83eea5769c218a90751409b310f42c261e61c0 Mon Sep 17 00:00:00 2001
From: Erik Pilkington <erik.pilkington@gmail.com>
Date: Sun, 28 May 2017 23:24:52 +0000
Subject: [PATCH] [ItaniumDemangle] Fix a exponential string copying bug

This is a port of libcxxabi's r304113.

llvm-svn: 304114
---
 llvm/lib/Demangle/ItaniumDemangle.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/lib/Demangle/ItaniumDemangle.cpp b/llvm/lib/Demangle/ItaniumDemangle.cpp
index 03d11a7..34f4017 100644
--- a/llvm/lib/Demangle/ItaniumDemangle.cpp
+++ b/llvm/lib/Demangle/ItaniumDemangle.cpp
@@ -2525,6 +2525,9 @@ static std::string base_name(std::string &s) {
       ++p0;
       break;
     }
+    if (!isalpha(*p0) && !isdigit(*p0) && *p0 != '_') {
+      return std::string();
+    }
   }
   return std::string(p0, pe);
 }
-- 
2.7.4