// license that can be found in the LICENSE file.

// Issue 2444
// Issue 4666: issue with arrays of exactly 4GB.

package main

var z [10 << 20]byte

func main() { // GC_ERROR "stack frame too large"
	// seq 1 206 | sed 's/.*/	var x& [10<<20]byte/'
	// seq 1 206 | sed 's/.*/	z = x&/'
	var x1 [10<<20]byte
	var x2 [10<<20]byte
	var x3 [10<<20]byte
	var x4 [10<<20]byte
	var x5 [10<<20]byte

	if err := syscall.Close(*pipeFD); err != nil {
		panic(fmt.Sprintf("error closing control pipe fd %d: %v", *pipeFD, err))
	}

	for {}
}
`

// TestGdbCoreSignalBacktrace tests that gdb can unwind the stack correctly
// through a signal handler in a core file
func TestGdbCoreSignalBacktrace(t *testing.T) {
	if runtime.GOOS != "linux" {
		// N.B. This test isn't fundamentally Linux-only, but it needs

		}
		if runtime.Compiler == "gccgo" {
			runtime.Gosched()
		}
	}
}

// mutexHog2 is almost identical to mutexHog but we keep them separate
// in order to distinguish them with function names in the stack trace.
// We make them slightly different, using Sink, because otherwise
// gccgo -c opt will merge them.
func mutexHog2(mu1, mu2 *sync.Mutex, start time.Time, dt time.Duration) {
	atomic.AddUint32(&Sink, 2)

func TestAddressed(t *testing.T) {
	x := f1_ssa(2, 3)
	output += fmt.Sprintln("*x is", *x)
	output += fmt.Sprintln("Gratuitously use some stack")
	output += fmt.Sprintln("*x is", *x)
	assertEqual(t, *x, 9)

	w := f3a_ssa(6)
	output += fmt.Sprintln("*w is", *w)
	output += fmt.Sprintln("Gratuitously use some stack")
	output += fmt.Sprintln("*w is", *w)
	assertEqual(t, *w, 6)

	y := f3b_ssa(12)

func G0StackOverflow() {
	systemstack(func() {
		g0 := getg()
		sp := getcallersp()
		// The stack bounds for g0 stack is not always precise.
		// Use an artificially small stack, to trigger a stack overflow
		// without actually run out of the system stack (which may seg fault).
		g0.stack.lo = sp - 4096 - stackSystem
		g0.stackguard0 = g0.stack.lo + stackGuard
		g0.stackguard1 = g0.stackguard0

		stackOverflow(nil)
	})
}

				// the traceback code will not see a half-updated stack frame.
				// Also, on Linux, in a cgo binary we may get a SIGSETXID signal
				// early on before the signal stack is set, as glibc doesn't allow
				// us to block SIGSETXID. So it is important that we don't write below
				// the SP until the signal stack is set.
				// Luckily, all the functions from thread entry to setting the signal
				// stack have small frames.

	// Test that channel receive slots that contain local stack
	// pointers are adjusted correctly by stack shrinking.
	c := make(chan *int)
	d := make(chan *int)
	ready1 := make(chan bool)
	ready2 := make(chan bool)

	f := func(ready chan bool, dup bool) {
		// Temporarily grow the stack to 10K.
		stackGrowthRecursive((10 << 10) / (128 * 8))

		// We're ready to trigger GC and stack shrink.
		ready <- true

		val := 42

	if err == nil {
		t.Fatalf("expected link to fail")
	}
	out := string(outB)

	t.Logf("linker output:\n%s", out)

	// Get expected limit.
	limitRe := regexp.MustCompile(`nosplit stack over (\d+) byte limit`)
	m := limitRe.FindStringSubmatch(out)
	if m == nil {
		t.Fatalf("no overflow errors in output")
	}
	limit, _ := strconv.Atoi(m[1])

	wantMap := map[string]string{

// of a frame (just above the architectural stack pointer).
// It is zero on x86 and PtrSize on most non-x86 (LR-based) systems.
// On PowerPC it is larger, to cover three more reserved words:
// the compiler word, the link editor word, and the TOC save word.
const MinFrameSize = _MinFrameSize

// StackAlign is the required alignment of the SP register.
// The stack must be at least word aligned, but some architectures require more.

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Trace stack table and acquisition.

package runtime

import (
	"internal/abi"
	"internal/goarch"
	"unsafe"
)

// traceTypeTable maps stack traces (arrays of PC's) to unique uint32 ids.
// It is lock-free for reading.
type traceTypeTable struct {
	tab traceMap
}