"time"
)

// viewerFrames returns the frames of the stack of ev. The given frame slice is
// used to store the frames to reduce allocations.
func viewerFrames(stk trace.Stack) []*trace.Frame {
	var frames []*trace.Frame
	stk.Frames(func(f trace.StackFrame) bool {
		frames = append(frames, &trace.Frame{
			PC:   f.PC,
			Fn:   f.Func,
			File: f.File,
			Line: int(f.Line),
		})
		return true
	})

package runtime

import (
	"internal/abi"
	"unsafe"
)

func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
	// Machine dependent mcontext initialisation for LWP.
	mc.__gregs[_REG_R15] = uint32(abi.FuncPCABI0(lwp_tramp))
	mc.__gregs[_REG_R13] = uint32(uintptr(stk))
	mc.__gregs[_REG_R0] = uint32(uintptr(unsafe.Pointer(mp)))
	mc.__gregs[_REG_R1] = uint32(uintptr(unsafe.Pointer(gp)))

package runtime

import (
	"internal/abi"
	"unsafe"
)

func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
	// Machine dependent mcontext initialisation for LWP.
	mc.__gregs[_REG_ELR] = uint64(abi.FuncPCABI0(lwp_tramp))
	mc.__gregs[_REG_X31] = uint64(uintptr(stk))
	mc.__gregs[_REG_X0] = uint64(uintptr(unsafe.Pointer(mp)))
	mc.__gregs[_REG_X1] = uint64(uintptr(unsafe.Pointer(mp.g0)))

		// TODO: Is it safe to osyield here? https://go.dev/issue/52672
		osyield()
	}

	if cpuprof.numExtra+1+len(stk) < len(cpuprof.extra) {
		i := cpuprof.numExtra
		cpuprof.extra[i] = uintptr(1 + len(stk))
		copy(cpuprof.extra[i+1:], stk)
		cpuprof.numExtra += 1 + len(stk)
	} else {
		cpuprof.lostExtra++
	}

	prof.signalLock.Store(0)
}

// addExtra adds the "extra" profiling events,

		ppid := data[2] >> 1
		if hasP := (data[2] & 0b1) != 0; !hasP {
			ppid = ^uint64(0)
		}
		goid := data[3]
		mpid := data[4]
		stk := data[5:recordLen]

		// Overflow records always have their headers contain
		// all zeroes.
		isOverflowRecord := len(stk) == 1 && data[2] == 0 && data[3] == 0 && data[4] == 0

		// Move the data iterator forward.
		data = data[recordLen:]

	})
}

func lwp_start(uintptr)

// May run with m.p==nil, so write barriers are not allowed.
//
//go:nowritebarrier
func newosproc(mp *m) {
	stk := unsafe.Pointer(mp.g0.stack.hi)
	if false {
		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " lwp_start=", abi.FuncPCABI0(lwp_start), " id=", mp.id, " ostk=", &mp, "\n")
	}

	var oset sigset
	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)

//
//go:noescape
func runtime_FrameSymbolName(f *runtime.Frame) string

// runtime_expandFinalInlineFrame is defined in runtime/symtab.go.
func runtime_expandFinalInlineFrame(stk []uintptr) []uintptr

// runtime_setProfLabel is defined in runtime/proflabel.go.
func runtime_setProfLabel(labels unsafe.Pointer)

// runtime_getProfLabel is defined in runtime/proflabel.go.

	. "runtime"
	"testing"
	"time"
	"unsafe"
)

func TestProfBuf(t *testing.T) {
	const hdrSize = 2

	write := func(t *testing.T, b *ProfBuf, tag unsafe.Pointer, now int64, hdr []uint64, stk []uintptr) {
		b.Write(&tag, now, hdr, stk)
	}
	read := func(t *testing.T, b *ProfBuf, data []uint64, tags []unsafe.Pointer) {
		rdata, rtags, eof := b.Read(ProfBufNonBlocking)
		if !reflect.DeepEqual(rdata, data) || !reflect.DeepEqual(rtags, tags) {

	SYSCALL
	BEQ	R7, 2(PC)
	SUBU	R2, R0, R2	// caller expects negative errno
	MOVW	R2, ret+24(FP)
	RET


// int32 clone(int32 flags, void *stk, M *mp, G *gp, void (*fn)(void));
TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0-24
	MOVW	flags+0(FP), R4
	MOVW	stk+4(FP), R5
	MOVW	R0, R6	// ptid
	MOVW	R0, R7	// tls

	// O32 syscall handler unconditionally copies arguments 5-8 from stack,