[llvm] r358237 - llvm-undname: Fix crash on incomplete virtual this adjusts

[Nico Weber via llvm-commits]

Author: nico
Date: Thu Apr 11 15:47:18 2019
New Revision: 358237

URL: http://llvm.org/viewvc/llvm-project?rev=358237&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp
    llvm/trunk/test/Demangle/invalid-manglings.test

Modified: llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp?rev=358237&r1=358236&r2=358237&view=diff
==============================================================================
--- llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp (original)
+++ llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp Thu Apr 11 15:47:18 2019
@@ -481,7 +481,7 @@ Demangler::demangleFunctionIdentifierCod
   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::demangleFunctionCla
     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);

Modified: llvm/trunk/test/Demangle/invalid-manglings.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Demangle/invalid-manglings.test?rev=358237&r1=358236&r2=358237&view=diff
==============================================================================
--- llvm/trunk/test/Demangle/invalid-manglings.test (original)
+++ llvm/trunk/test/Demangle/invalid-manglings.test Thu Apr 11 15:47:18 2019
@@ -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