}

// ParseGo populates f with information learned from the Go source code
// which was read from the named file. It gathers the C preamble
// attached to the import "C" comment, a list of references to C.xxx,
// a list of exported functions, and the actual AST, to be rewritten and
// printed.
func (f *File) ParseGo(abspath string, src []byte) {
	// Two different parses: once with comments, once without.

	_cgo_export.h   # for gcc
	_cgo_main.c     # for gcc
	_cgo_flags      # for build tool (if -gccgo)

The file x.cgo1.go is a copy of x.go with the import "C" removed and
references to C.xxx replaced with names like _Cfunc_xxx or _Ctype_xxx.
The definitions of those identifiers, written as Go functions, types,
or variables, are provided in _cgo_gotypes.go.

Here is a _cgo_gotypes.go containing definitions for needed C types:

	}
	fmt.Fprintf(os.Stderr, "%s:%d: %s", in.File(), in.Line(), fmt.Sprintln(args...))
	os.Exit(1)
}

// expectText is like Error but adds "got XXX" where XXX is a quoted representation of the most recent token.
func (in *Input) expectText(args ...interface{}) {
	in.Error(append(args, "; got", strconv.Quote(in.Stack.Text()))...)
}

			s := s.(*ast.TypeSpec)
			n := refName[&s.Type]
			if n != nil && n.Mangle != "" {
				override[n.Mangle] = s.Name.Name
			}
		}
	}

	// Extend overrides using typedefs:
	// If we know that C.xxx should format as T
	// and xxx is a typedef for yyy, make C.yyy format as T.
	for typ, def := range typedef {
		if new := override[typ]; new != "" {
			if id, ok := def.Go.(*ast.Ident); ok {
				override[id.Name] = new
			}
		}
	}

	//
	// For each name, we generate these lines, where xxx is the index in toSniff plus one.
	//
	//	#line xxx "not-declared"
	//	void __cgo_f_xxx_1(void) { __typeof__(name) *__cgo_undefined__1; }
	//	#line xxx "not-type"
	//	void __cgo_f_xxx_2(void) { name *__cgo_undefined__2; }
	//	#line xxx "not-int-const"
	//	void __cgo_f_xxx_3(void) { enum { __cgo_undefined__3 = (name)*1 }; }
	//	#line xxx "not-num-const"

attempt to auto-detect suitable values. Run it as

	go run detect.go

which will output something similar to

	export GOIOS_DEV_ID="iPhone Developer: xxx@yyy.zzz (XXXXXXXX)"
	export GOIOS_APP_ID=YYYYYYYY.some.bundle.id
	export GOIOS_TEAM_ID=ZZZZZZZZ

If you have multiple devices connected, specify the device UDID with the GOIOS_DEVICE_ID

	var _C_zero *C.mpz_t

and then replacing all instances of C.zero with (*_C_zero).

Cgo's most interesting translation is for functions.  If xxx is a C
function, then cgo rewrites C.xxx into a new function _C_xxx that
calls the C xxx in a standard pthread.  The new function translates
its arguments, calls xxx, and translates the return value.

Translation of parameters and the return value follows the type

// We have consumed the register or R prefix.
func (p *Parser) atRegisterExtension() bool {
	// ARM64 only.
	if p.arch.Family != sys.ARM64 {
		return false
	}
	// R1.xxx
	return p.peek() == '.'
}

// registerReference parses a register given either the name, R10, or a parenthesized form, SPR(10).
func (p *Parser) registerReference(name string) (int16, bool) {

pkg syscall (darwin-386), const IP_MULTICAST_LOOP = 11
pkg syscall (darwin-386), const IP_MULTICAST_TTL = 10
pkg syscall (darwin-386), const IP_MULTICAST_VIF = 14
pkg syscall (darwin-386), const IP_NAT__XXX = 55
pkg syscall (darwin-386), const IP_OFFMASK = 8191
pkg syscall (darwin-386), const IP_OLD_FW_ADD = 50
pkg syscall (darwin-386), const IP_OLD_FW_DEL = 51
pkg syscall (darwin-386), const IP_OLD_FW_FLUSH = 52

pkg syscall (darwin-arm64), const IP_MULTICAST_VIF = 14
pkg syscall (darwin-arm64), const IP_MULTICAST_VIF ideal-int
pkg syscall (darwin-arm64), const IP_NAT__XXX = 55
pkg syscall (darwin-arm64), const IP_NAT__XXX ideal-int
pkg syscall (darwin-arm64), const IP_OFFMASK = 8191
pkg syscall (darwin-arm64), const IP_OFFMASK ideal-int
pkg syscall (darwin-arm64), const IP_OLD_FW_ADD = 50