var traceback_cache uint32 = 2 << tracebackShift
var traceback_env uint32

// gotraceback returns the current traceback settings.
//
// If level is 0, suppress all tracebacks.
// If level is 1, show tracebacks, but exclude runtime frames.
// If level is 2, show tracebacks including runtime frames.
// If all is set, print all goroutine stacks. Otherwise, print just the current goroutine.
// If crash is set, crash (core dump, etc) after tracebacking.

		u.initAt(mp.vdsoPC, mp.vdsoSP, 0, gp, unwindSilentErrors|unwindJumpStack)
	} else {
		u.initAt(pc, sp, lr, gp, unwindSilentErrors|unwindTrap|unwindJumpStack)
	}
	n += tracebackPCs(&u, 0, stk[n:])

	if n <= 0 {
		// Normal traceback is impossible or has failed.
		// Account it against abstract "System" or "GC".
		n = 2
		if inVDSOPage(pc) {

func (s *pcinlineState) addBranch(ctxt *Link, globalIndex int) int {
	if globalIndex < 0 {
		return -1
	}

	localIndex, ok := s.globalToLocal[globalIndex]
	if ok {
		return localIndex
	}

	// Since tracebacks don't include column information, we could
	// use one node for multiple calls of the same function on the
	// same line (e.g., f(x) + f(y)). For now, we use one node for
	// each inlined call.

// not be skipped if only -quick is used.
var flagQuick = flag.Bool("quick", false, "skip slow tests, for cmd/dist test runtime:cpu124")

func init() {
	// We're testing the runtime, so make tracebacks show things
	// in the runtime. This only raises the level, so it won't
	// override GOTRACEBACK=crash from the user.
	SetTracebackEnv("system")
}

var errf error

func errfn() error {
	return errf
}

}

// 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)

func (w ttiWrapper) m1() *ttiResult {
	return ttiLeaf()
}

//go:noinline
func ttiExcluded1() *ttiResult {
	return ttiExcluded2()
}

// ttiExcluded2 should be excluded from tracebacks. There are
// various ways this could come up. Linking it to a "runtime." name is
// rather synthetic, but it's easy and reliable. See issue #42754 for
// one way this happened in real code.
//

	schedtrace: setting schedtrace=X causes the scheduler to emit a single line to standard
	error every X milliseconds, summarizing the scheduler state.

	tracebackancestors: setting tracebackancestors=N extends tracebacks with the stacks at
	which goroutines were created, where N limits the number of ancestor goroutines to
	report. This also extends the information returned by runtime.Stack.
	Setting N to 0 will report no ancestry information.

		if l, ok := b.locs[addr]; ok {
			// When generating code for an inlined function, the compiler adds
			// NOP instructions to the outermost function as a placeholder for
			// each layer of inlining. When the runtime generates tracebacks for
			// stacks that include inlined functions, it uses the addresses of
			// those NOPs as "fake" PCs on the stack as if they were regular
			// function call sites. But if a profiling signal arrives while the

// memory. It checks whether that Go memory contains any other
// pointer into unpinned Go memory. If it does, we panic.
// The return values are unused but useful to see in panic tracebacks.
func cgoCheckUnknownPointer(p unsafe.Pointer, msg string) (base, i uintptr) {
	if inheap(uintptr(p)) {
		b, span, _ := findObject(uintptr(p), 0, 0)
		base = b
		if base == 0 {
			return
		}

	MOVV	m_curg(R1), g
	JAL	runtime·save_g(SB)
	MOVV	(g_sched+gobuf_sp)(g), R29
	MOVV	R0, (g_sched+gobuf_sp)(g)
	RET

noswitch:
	// already on m stack, just call directly
	// Using a tail call here cleans up tracebacks since we won't stop
	// at an intermediate systemstack.
	MOVV	0(REGCTXT), R4	// code pointer
	MOVV	0(R29), R31	// restore LR
	ADDV	$8, R29
	JMP	(R4)

// func switchToCrashStack0(fn func())