From e46e354ecb9a04c8d3724ae2b0f95f4424e3f69c Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Mon, 20 Apr 2009 06:13:16 +0000
Subject: [PATCH] Don't crash in the diagnostic printer if we happen to get
 passed a null string / identifier.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69575 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Basic/Diagnostic.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 9986fc5a41..d5d8da1e22 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -714,6 +714,11 @@ FormatDiagnostic(llvm::SmallVectorImpl<char> &OutStr) const {
     case Diagnostic::ak_c_string: {
       const char *S = getArgCStr(ArgNo);
       assert(ModifierLen == 0 && "No modifiers for strings yet");
+
+      // Don't crash if get passed a null pointer by accident.
+      if (!S)
+        S = "(null)";
+      
       OutStr.append(S, S + strlen(S));
       break;
     }
@@ -757,6 +762,14 @@ FormatDiagnostic(llvm::SmallVectorImpl<char> &OutStr) const {
     case Diagnostic::ak_identifierinfo: {
       const IdentifierInfo *II = getArgIdentifier(ArgNo);
       assert(ModifierLen == 0 && "No modifiers for strings yet");
+
+      // Don't crash if get passed a null pointer by accident.
+      if (!II) {
+        const char *S = "(null)";
+        OutStr.append(S, S + strlen(S));
+        continue;
+      }
+
       OutStr.push_back('\'');
       OutStr.append(II->getName(), II->getName() + II->getLength());
       OutStr.push_back('\'');
-- 
2.40.0