[clang] [llvm] [win][aarch64] Always reserve frame pointers for Arm64 Windows (PR #146582)

[Daniel Paoliello via llvm-commits]

================
@@ -518,6 +518,27 @@ bool AArch64FrameLowering::hasFPImpl(const MachineFunction &MF) const {
   return false;
 }
 
+/// Should the Frame Pointer be reserved for the current function?
+bool AArch64FrameLowering::isFPReserved(const MachineFunction &MF) const {
+  const TargetMachine &TM = MF.getTarget();
+  const Triple &TT = TM.getTargetTriple();
+
+  // These OSes require the frame chain is valid, even if the current frame does
+  // not use a frame pointer.
+  if (TT.isOSDarwin() || TT.isOSWindows())
----------------
dpaoliello wrote:

I'm not familiar with how flang works, but if it's going to scrape(?) the command line args from clang, then it needs to be able to handle all the same command line arguments that clang does.

This is not a bug in clang: this is a bug in flang and would be hit if anyone tried building Arm32 code in flang.

https://github.com/llvm/llvm-project/pull/146582