These rules are checked dynamically at runtime. The checking is
controlled by the cgocheck setting of the GODEBUG environment
variable. The default setting is GODEBUG=cgocheck=1, which implements
reasonably cheap dynamic checks. These checks may be disabled
entirely using GODEBUG=cgocheck=0. Complete checking of pointer
handling, at some cost in run time, is available by setting
GOEXPERIMENT=cgocheck2 at build time.

	// Second, if ContentErr==nil, the content should match Content.
	// If content is large, an alternative to setting Content is to set File,
	// which names a file in the testdata/ directory containing the
	// uncompressed expected content.
	// If content is very large, an alternative to setting Content or File
	// is to set Size, which will then be checked against the header-reported size

x[i], i = 2, 1  // set x[0] = 2, i = 1

x[0], x[0] = 1, 2  // set x[0] = 1, then x[0] = 2 (so x[0] == 2 at end)

x[1], x[3] = 4, 5  // set x[1] = 4, then panic setting x[3] = 5.

type Point struct { x, y int }
var p *Point
x[2], p.x = 6, 7  // set x[2] = 6, then panic setting p.x = 7

i = 2
x = []int{3, 5, 7}
for i, x[i] = range x {  // set i, x[2] = 0, x[0]
	break
}

These new behaviors are only enabled when the main Go program
is in a module with a `go.mod` `go` line using Go 1.23.0 or later.
When Go 1.23 builds older programs, the old behaviors remain in effect.
The new [GODEBUG setting](/doc/godebug) [`asynctimerchan=1`](/pkg/time/#NewTimer)
can be used to revert back to asynchronous channel behaviors

	flag.Var(objabi.NewDebugFlag(&DebugFlags, nil), "d", "enable debugging settings; try -d help")
	objabi.AddVersionFlag() // -V
	objabi.Flagcount("S", "print assembly and machine code", &PrintOut)
}

// MultiFlag allows setting a value multiple times to collect a list, as in -I=dir1 -I=dir2.
type MultiFlag []string

func (m *MultiFlag) String() string {
	if len(*m) == 0 {
		return ""
	}
	return fmt.Sprint(*m)
}

// built-in function recover.
//
// Starting in Go 1.21, calling panic with a nil interface value or an
// untyped nil causes a run-time error (a different panic).
// The GODEBUG setting panicnil=1 disables the run-time error.
func panic(v any)

// The recover built-in function allows a program to manage behavior of a
// panicking goroutine. Executing a call to recover inside a deferred

		c0 := sep[0]
		c1 := sep[1]
		i := 0
		t := len(s) - n + 1
		fails := 0
		for i < t {
			if s[i] != c0 {
				// IndexByte is faster than bytealg.Index, so use it as long as
				// we're not getting lots of false positives.
				o := IndexByte(s[i+1:t], c0)
				if o < 0 {
					return -1
				}
				i += o + 1
			}
			if s[i+1] == c1 && Equal(s[i:i+n], sep) {
				return i
			}

pkg syscall (darwin-386), const SYS_SETSGROUPS = 287
pkg syscall (darwin-386), const SYS_SETSID = 147
pkg syscall (darwin-386), const SYS_SETSOCKOPT = 105
pkg syscall (darwin-386), const SYS_SETTID = 285
pkg syscall (darwin-386), const SYS_SETTID_WITH_PID = 311
pkg syscall (darwin-386), const SYS_SETTIMEOFDAY = 122
pkg syscall (darwin-386), const SYS_SETUID = 23
pkg syscall (darwin-386), const SYS_SETWGROUPS = 289

x[i], i = 2, 1  // set x[0] = 2, i = 1

x[0], x[0] = 1, 2  // set x[0] = 1, then x[0] = 2 (so x[0] == 2 at end)

x[1], x[3] = 4, 5  // set x[1] = 4, then panic setting x[3] = 5.

type Point struct { x, y int }
var p *Point
x[2], p.x = 6, 7  // set x[2] = 6, then panic setting p.x = 7

i = 2
x = []int{3, 5, 7}
for i, x[i] = range x {  // set i, x[2] = 0, x[0]
	break
}

//go:build linux

package cgotest

/*
#include <unistd.h>
#include <stdbool.h>
#include <sys/syscall.h>
void Gosched(void);
static bool Ctid(void) {
	long tid1 = syscall(SYS_gettid);
	Gosched();
	return tid1 == syscall(SYS_gettid);
}
*/
import "C"

import (
	"runtime"
	"testing"
	"time"
)

//export Gosched
func Gosched() {
	runtime.Gosched()
}

func init() {