From: Nico Weber <nicolasweber@gmx.de>
Date: Thu, 11 Apr 2019 22:47:18 +0000 (+0000)
Subject: llvm-undname: Fix crash on incomplete virtual this adjusts
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=65c0092a7b05fe65906a3144ddf57303d20123b3;p=llvm

llvm-undname: Fix crash on incomplete virtual this adjusts

Found by oss-fuzz.

Also remove an else-after-return, this part has no behavior change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358237 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Demangle/MicrosoftDemangle.cpp b/lib/Demangle/MicrosoftDemangle.cpp
index 194a152acb8..f45df9413d7 100644
--- a/lib/Demangle/MicrosoftDemangle.cpp
+++ b/lib/Demangle/MicrosoftDemangle.cpp
@@ -481,7 +481,7 @@ Demangler::demangleFunctionIdentifierCode(StringView &MangledName) {
   if (MangledName.consumeFront("__"))
     return demangleFunctionIdentifierCode(
         MangledName, FunctionIdentifierCodeGroup::DoubleUnder);
-  else if (MangledName.consumeFront("_"))
+  if (MangledName.consumeFront("_"))
     return demangleFunctionIdentifierCode(MangledName,
                                           FunctionIdentifierCodeGroup::Under);
   return demangleFunctionIdentifierCode(MangledName,
@@ -1575,7 +1575,8 @@ FuncClass Demangler::demangleFunctionClass(StringView &MangledName) {
     FuncClass VFlag = FC_VirtualThisAdjust;
     if (MangledName.consumeFront('R'))
       VFlag = FuncClass(VFlag | FC_VirtualThisAdjustEx);
-
+    if (MangledName.empty())
+      break;
     switch (MangledName.popFront()) {
     case '0':
       return FuncClass(FC_Private | FC_Virtual | VFlag);
diff --git a/test/Demangle/invalid-manglings.test b/test/Demangle/invalid-manglings.test
index 5d6f3160a95..4c155b765a4 100644
--- a/test/Demangle/invalid-manglings.test
+++ b/test/Demangle/invalid-manglings.test
@@ -99,3 +99,8 @@
 ; CHECK-EMPTY:
 ; CHECK-NEXT: ?B@?$?K$H?
 ; CHECK-NEXT: error: Invalid mangled name
+
+??C@$
+; CHECK-EMPTY:
+; CHECK-NEXT: ??C@$
+; CHECK-NEXT: error: Invalid mangled name