//
// fpunwindExpand checks if pcBuf contains logical frames (which include inlined
// frames) or physical frames (produced by frame pointer unwinding) using a
// sentinel value in pcBuf[0]. Logical frames are simply returned without the
// sentinel. Physical frames are turned into logical frames via inline unwinding
// and by applying the skip value that's stored in pcBuf[0].
func fpunwindExpand(dst, pcBuf []uintptr) int {
	if len(pcBuf) == 0 {

}

func TestFPUnwindAfterRecovery(t *testing.T) {
	if !runtime.FramePointerEnabled {
		t.Skip("frame pointers not supported for this architecture")
	}
	// Make sure that frame pointer unwinding succeeds from a deferred
	// function run after recovering from a panic. It can fail if the
	// recovery does not properly restore the caller's frame pointer before
	// running the remaining deferred functions.
	//

// is a problem because sometimes functions exit via panic instead
// of an ordinary return, so panic would have to know to do the
// same math when unwinding the stack. It gets complicated fast.
// This particular test never worked with the old scheme, because
// panic never did the right unwinding math.
//
// The new scheme adjusts Panic.argp on entry to a wrapper.
// It has no exit work, so if a wrapper is interrupted by a panic,

	}

	// After this point, it is safe to grow the stack.

	// Make it look like a call to the signal func.
	// Have to pass arguments out of band since
	// augmenting the stack frame would break
	// the unwinding code.
	gp.sig = info.exceptioncode
	gp.sigcode0 = info.exceptioninformation[0]
	gp.sigcode1 = info.exceptioninformation[1]
	gp.sigpc = r.ip()

	// Only push runtime·sigpanic if r.ip() != 0.

		// here we'll see a seemingly self-recursive call, which is in
		// fact not.
		// This is normally ok, as we use the return address saved on
		// stack for unwinding, not the LR value. But if this is a
		// call to morestack, we haven't created the frame, and we'll
		// use the LR for unwinding, which will be bad.
		return false, 0
	}
	up, startpc := pcdatavalue2(f, abi.PCDATA_UnsafePoint, pc)
	if up == abi.UnsafePointUnsafe {

	// and String methods to prepare the panic strings before startpanic.
	preprintpanics(&p)

	fatalpanic(&p)   // should not return
	*(*int)(nil) = 0 // not reached
}

// start initializes a panic to start unwinding the stack.
//
// If p.goexit is true, then start may return multiple times.
func (p *_panic) start(pc uintptr, sp unsafe.Pointer) {
	gp := getg()

	// Record the caller's PC and SP, so recovery can identify panics

   Threads:

   Wasm doesn't (yet) have threads. We have to simulate threads by
   keeping goroutine stacks in linear memory and unwinding
   the Wasm stack each time we want to switch goroutines.

   To support unwinding a stack, each function call returns on the Wasm
   stack a boolean that tells the function whether it should return
   immediately or not. When returning immediately, a return address

// Then it calls _cgoexp_GoF(frame).
//
// _cgoexp_GoF, which was generated by cmd/cgo, unpacks the arguments
// from frame, calls p.GoF, writes the results back to frame, and
// returns. Now we start unwinding this whole process.
//
// runtime.cgocallbackg pops but does not execute the deferred
// function to unwind m.g0.sched.sp, calls runtime.entersyscall, and
// returns to runtime.cgocallback.
//

	MOVQ	runtime·cgoTraceback(SB), CX
	MOVQ	$runtime·sigprofCallers(SB), R8
	MOVQ	$runtime·sigprofNonGoWrapper<>(SB), R9
	MOVQ	_cgo_callers(SB), AX
	JMP	AX

// For cgo unwinding to work, this function must look precisely like
// the one in glibc. The glibc source code is:

				// trying to unwind WebAssembly stack but call has no resume point, terminate with error
				p = appendp(p, AIf)
				p = appendp(p, obj.AUNDEF)
				p = appendp(p, AEnd)
			} else {
				// unwinding WebAssembly stack to switch goroutine, return 1
				p = appendp(p, ABrIf)
				unwindExitBranches = append(unwindExitBranches, p)
			}

		case obj.ARET, ARETUNWIND:
			ret := *p
			p.As = obj.ANOP