[llvm] r314793 - [ARM, Asm] Fix ubsan failure caused by out-of-range enum value

[Oliver Stannard via llvm-commits]

Author: olista01
Date: Tue Oct  3 05:45:18 2017
New Revision: 314793

URL: http://llvm.org/viewvc/llvm-project?rev=314793&view=rev
Log:
[ARM, Asm] Fix ubsan failure caused by out-of-range enum value

In this code, we use ~0U as a sentinel value for any operand class that doesn't
have a user-friendly error message, but this value isn't in range of the
MatchClassKind enum, so we need to ensure it does not get passed to isSubclass.


Modified:
    llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp

Modified: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp?rev=314793&r1=314792&r2=314793&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp Tue Oct  3 05:45:18 2017
@@ -10211,8 +10211,8 @@ ARMAsmParser::FilterNearMisses(SmallVect
       if (std::any_of(PrevReports.first, PrevReports.second,
                       [DupCheckMatchClass](
                           const std::pair<unsigned, unsigned> Pair) {
-            if (DupCheckMatchClass == ~0U)
-              return Pair.second == ~0U;
+            if (DupCheckMatchClass == ~0U || Pair.second == ~0U)
+              return Pair.second == DupCheckMatchClass;
             else
               return isSubclass((MatchClassKind)DupCheckMatchClass,
                                 (MatchClassKind)Pair.second);