UNDEF

/*
 * support for morestack
 */

// Called during function prolog when more stack is needed.
// Caller has already loaded:
// R3: framesize, R4: argsize, R5: LR
//
// The traceback routines see morestack on a g0 as being
// the top of a stack (for example, morestack calling newstack
// calling the scheduler calling newm calling gc), so we must

will cause an immediate fatal error, such as when called on the system
stack or when called during `mallocgc`.

Most errors in the runtime are not recoverable. For these, use
`throw`, which dumps the traceback and immediately terminates the
process. In general, `throw` should be passed a string constant to
avoid allocating in perilous situations. By convention, additional

			q = p

			if autosize != 0 {
				// Make sure to save link register for non-empty frame, even if
				// it is a leaf function, so that traceback works.
				// Store link register before decrement SP, so if a signal comes
				// during the execution of the function prologue, the traceback
				// code will not see a half-updated stack frame.
				// This sequence is not async preemptible, as if we open a frame

	// so switch to g0.

	// Save old SP. Use R13 instead of SP to avoid linker rewriting the offsets.
	MOVW	R13, R5

	MOVW	g_m(g), R6

	// Set vdsoPC and vdsoSP for SIGPROF traceback.
	// Save the old values on stack and restore them on exit,
	// so this function is reentrant.
	MOVW	m_vdsoPC(R6), R7
	MOVW	m_vdsoSP(R6), R8
	MOVW	R7, 4(R13)
	MOVW	R8, 8(R13)

//go:nosplit
func (l *dlogger) pc(x uintptr) *dlogger {
	if !dlogEnabled {
		return l
	}
	l.w.byte(debugLogPC)
	l.w.uvarint(uint64(x))
	return l
}

//go:nosplit
func (l *dlogger) traceback(x []uintptr) *dlogger {
	if !dlogEnabled {
		return l
	}
	l.w.byte(debugLogTraceback)
	l.w.uvarint(uint64(len(x)))
	for _, pc := range x {
		l.w.uvarint(uint64(pc))
	}
	return l
}

}

// A ScopeID represents a lexical scope within a function.
type ScopeID int32

const (
	funcDupok      = 1 << iota // duplicate definitions ok
	funcWrapper                // hide frame from users (elide in tracebacks, don't count as a frame for recover())
	funcABIWrapper             // is an ABI wrapper (also set flagWrapper)
	funcNeedctxt               // function uses context register (has closure variables)

// the calling Go function that it should not jump
// to deferreturn.
// in asm_*.s
func return0()

// in asm_*.s
// not called directly; definitions here supply type information for traceback.
// These must have the same signature (arg pointer map) as reflectcall.
func call16(typ, fn, stackArgs unsafe.Pointer, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs)

				var prologueEnd *obj.Prog
				// Save the link register and update the SP.  MOVDU is used unless
				// the frame size is too large.  The link register must be saved
				// even for non-empty leaf functions so that traceback works.
				if autosize >= -BIG && autosize <= BIG {
					// Use MOVDU to adjust R1 when saving R31, if autosize is small.
					q = obj.Appendp(q, c.newprog)
					q.As = AMOVD
					q.Pos = p.Pos

			throw("markroot: bad index")
		}
		gp := work.stackRoots[i-work.baseStacks]

		// remember when we've first observed the G blocked
		// needed only to output in traceback
		status := readgstatus(gp) // We are not in a scan state
		if (status == _Gwaiting || status == _Gsyscall) && gp.waitsince == 0 {
			gp.waitsince = work.tstart
		}

		// timer). But it may have never interacted with the Go scheduler, or
		// never while profiling was active. To avoid double-counting, process
		// only signals from setitimer.
		//
		// When a custom cgo traceback function has been registered (on
		// platforms that support runtime.SetCgoTraceback), SIGPROF signals
		// delivered to a thread that cannot find a matching M do this check in