[RISCV] Fix crash in parseZcmpStackAdj if token is not an integer.

Author: topperc

llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp

@@ -2676,7 +2676,11 @@ ParseStatus RISCVAsmParser::parseZcmpStackAdj(OperandVector &Operands,
   bool Negative = parseOptionalToken(AsmToken::Minus);
 
   SMLoc S = getLoc();
-  int64_t StackAdjustment = getLexer().getTok().getIntVal();
+
+  if (getTok().isNot(AsmToken::Integer))
+    return ParseStatus::NoMatch;
+
+  int64_t StackAdjustment = getTok().getIntVal();
   unsigned RlistVal = static_cast<RISCVOperand *>(Operands[1].get())->Rlist.Val;
 
   assert(RlistVal != RISCVZC::INVALID_RLIST);
@@ -2697,7 +2701,7 @@ ParseStatus RISCVAsmParser::parseZcmpStackAdj(OperandVector &Operands,
 
   unsigned Spimm = (StackAdjustment - StackAdjBase) / 16;
   Operands.push_back(RISCVOperand::createSpimm(Spimm << 4, S));
-  getLexer().Lex();
+  Lex();
   return ParseStatus::Success;
 }
 

llvm/test/MC/RISCV/rv64zcmp-invalid.s

@@ -48,3 +48,9 @@ cm.pop {ra, x8-x9, x18-x17}, -40
 
 # CHECK-ERROR: :[[@LINE+1]]:16: error: invalid register
 cm.pop {ra, x8-f8, x18-x17}, -40
+
+# CHECK-ERROR: :[[@LINE+1]]:15: error: stack adjustment is invalid for this instruction and register list
+cm.pop {ra}, -x1
+
+# CHECK-ERROR: :[[@LINE+1]]:15: error: stack adjustment is invalid for this instruction and register list
+cm.push {ra}, x1