[M68k] Fix printing of immediate in `M68kOperand::print`

[ids1024]

Summary

The Imm union variant wasn't initialized anywhere. This fixes what is printed by llvm-mc -arch m68k --show-inst-operands.

[myhsu]

Thanks for spotting this issue. Could you add a (regression) test? Normally people just used the code that triggered the issue.

llvm/lib/Target/M68k/AsmParser/M68kAsmParser.cpp

1070–1071

curly braces are required for this case since there is a variable declaration within.

[ids1024]

Regression test and curly braces.

[myhsu]

LGTM Thanks!

llvm/lib/Target/M68k/AsmParser/M68kAsmParser.cpp

enum class KindTy {
     Imm,
     MemOp,
   };
 
   KindTy Kind;
   SMLoc Start, End;
   union {
     StringRef Token;
-    int64_t Imm;
     const MCExpr *Expr;
     M68kMemOp MemOp;
   };
 
   template <unsigned N> bool isAddrN() const;
 
 public:
   M68kOperand(KindTy Kind, SMLoc Start, SMLoc End)
void M68kOperand::print(raw_ostream &OS) const {
   switch (Kind) {
   case KindTy::Invalid:
     OS << "invalid";
     break;
 
   case KindTy::Token:
     OS << "token '" << Token << "'";
     break;
 
-  case KindTy::Imm:
-    OS << "immediate " << Imm;
+  case KindTy::Imm: {
+    int64_t Value;
+    Expr->evaluateAsAbsolute(Value);
+    OS << "immediate " << Value;
     break;
+  }
 
   case KindTy::MemOp:
     MemOp.print(OS);
     break;
   }
 }

llvm/test/MC/M68k/operand.s

+# RUN: llvm-mc -triple=m68k -show-inst-operands %s 2> %t0
+# RUN: FileCheck %s < %t0
+
+; CHECK:  parsed instruction: [token 'move.l', immediate 123, %24]
+move.l  #123, %d0