AsmParser: extractvalue requires at least one index operand

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229365 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/LLParser.cpp

@@ -1633,6 +1633,7 @@ bool LLParser::ParseIndexList(SmallVectorImpl<unsigned> &Indices,
 
   while (EatIfPresent(lltok::comma)) {
     if (Lex.getKind() == lltok::MetadataVar) {
+      if (Indices.empty()) return TokError("expected index");
       AteExtraComma = true;
       return false;
     }

test/Assembler/extractvalue-no-idx.ll

@@ -0,0 +1,8 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+; CHECK: expected index
+
+define void @f1() {
+  extractvalue <{ i32, i32 }> undef, !dbg !0
+  ret void
+}