comment, called the preamble, is used as a header when compiling
the C parts of the package. For example:

	// #include <stdio.h>
	// #include <errno.h>
	import "C"

The preamble may contain any C code, including function and variable
declarations and definitions. These may then be referred to from Go
code as though they were defined in the package "C". All names

SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
</pre>

<p>
There are two forms: expression switches and type switches.
In an expression switch, the cases contain expressions that are compared
against the value of the switch expression.
In a type switch, the cases contain types that are compared against the
type of a specially annotated switch expression.
The switch expression is evaluated exactly once in a switch statement.
</p>

	paxGNUSparseSize      = "GNU.sparse.size"
	paxGNUSparseRealSize  = "GNU.sparse.realsize"
)

// basicKeys is a set of the PAX keys for which we have built-in support.
// This does not contain "charset" or "comment", which are both PAX-specific,
// so adding them as first-class features of Header is unlikely.
// Users can use the PAXRecords field to set it themselves.
var basicKeys = map[string]bool{

// forces us to be a more liberal.
// Thus, we only reject all keys with NUL, and only reject NULs in values
// for the PAX version of the USTAR string fields.
// The key must not contain an '=' character.
func validPAXRecord(k, v string) bool {
	if k == "" || strings.Contains(k, "=") {
		return false
	}
	switch k {
	case paxPath, paxLinkpath, paxUname, paxGname:
		return !hasNUL(v)

	return sb.String(), needsUnsafe
}

// needsPointerCheck reports whether the type t needs a pointer check.
// This is true if t is a pointer and if the value to which it points
// might contain a pointer.
func (p *Package) needsPointerCheck(f *File, t ast.Expr, arg ast.Expr) bool {
	// An untyped nil does not need a pointer check, and when
	// _cgoCheckPointer returns the untyped nil the type assertion we

pkg syscall (darwin-arm64), type Log2phys_t struct, Devoffset int64
pkg syscall (darwin-arm64), type Log2phys_t struct, Flags uint32
pkg syscall (darwin-arm64), type Msghdr struct
pkg syscall (darwin-arm64), type Msghdr struct, Control *uint8
pkg syscall (darwin-arm64), type Msghdr struct, Controllen uint32
pkg syscall (darwin-arm64), type Msghdr struct, Flags int32
pkg syscall (darwin-arm64), type Msghdr struct, Iov *Iovec

pkg syscall (freebsd-arm64), type Kevent_t struct, Ident uint64
pkg syscall (freebsd-arm64), type Kevent_t struct, Udata *uint8
pkg syscall (freebsd-arm64), type Msghdr struct
pkg syscall (freebsd-arm64), type Msghdr struct, Control *uint8
pkg syscall (freebsd-arm64), type Msghdr struct, Controllen uint32
pkg syscall (freebsd-arm64), type Msghdr struct, Flags int32
pkg syscall (freebsd-arm64), type Msghdr struct, Iov *Iovec

pkg syscall, type Conn interface { SyscallConn }
pkg syscall, type Conn interface, SyscallConn() (RawConn, error)
pkg syscall, type RawConn interface { Control, Read, Write }
pkg syscall, type RawConn interface, Control(func(uintptr)) error
pkg syscall, type RawConn interface, Read(func(uintptr) bool) error
pkg syscall, type RawConn interface, Write(func(uintptr) bool) error
pkg testing, method (*B) Helper()

func pageIDs(body string) (ids []string) {
	mv := idRx.FindAllStringSubmatch(body, -1)
	for _, m := range mv {
		ids = append(ids, m[1])
	}
	return
}

// url may contain a #fragment, and the fragment is then noted as needing to exist.
func crawl(url string, sourceURL string) {
	if strings.Contains(url, "/devel/release") {
		return
	}
	mu.Lock()
	defer mu.Unlock()

	0x0043 00067 (x.go:3)	PCDATA	$0, $-1
	0x0043 00067 (x.go:3)	CALL	runtime.morestack_noctxt(SB)
	0x0048 00072 (x.go:3)	JMP	0
...
</pre>

<p>
The <code>FUNCDATA</code> and <code>PCDATA</code> directives contain information
for use by the garbage collector; they are introduced by the compiler.
</p>

<p>
To see what gets put in the binary after linking, use <code>go tool objdump</code>:
</p>

<pre>