declarations and definitions. These may then be referred to from Go
code as though they were defined in the package "C". All names
declared in the preamble may be used, even if they start with a
lower-case letter. Exception: static variables in the preamble may
not be referenced from Go code; static functions are permitted.

See $GOROOT/cmd/cgo/internal/teststdio and $GOROOT/misc/cgo/gmp for examples. See

unicode_letter = /* a Unicode code point classified as "Letter" */ .
unicode_digit  = /* a Unicode code point classified as "Number, decimal digit" */ .
</pre>

<p>
In <a href="https://www.unicode.org/versions/Unicode8.0.0/">The Unicode Standard 8.0</a>,
Section 4.5 "General Category" defines a set of character categories.
Go treats all characters in any of the Letter categories Lu, Ll, Lt, Lm, or Lo

	{"$0xfffffffffffff001", "$-4095"},
	{"$1", "$1"},
	{"$1.0", "$(1.0)"},
	{"$10", "$10"},
	{"$1000", "$1000"},
	{"$1000000", "$1000000"},
	{"$1000000000", "$1000000000"},
	{"$__tsan_func_enter(SB)", "$__tsan_func_enter(SB)"},
	{"$main(SB)", "$main(SB)"},
	{"$masks<>(SB)", "$masks<>(SB)"},
	{"$setg_gcc<>(SB)", "$setg_gcc<>(SB)"},
	{"$shifts<>(SB)", "$shifts<>(SB)"},
	{"$~(1<<63)", "$9223372036854775807"},

unicode_letter = /* a Unicode code point categorized as "Letter" */ .
unicode_digit  = /* a Unicode code point categorized as "Number, decimal digit" */ .
</pre>

<p>
In <a href="https://www.unicode.org/versions/Unicode8.0.0/">The Unicode Standard 8.0</a>,
Section 4.5 "General Category" defines a set of character categories.
Go treats all characters in any of the Letter categories Lu, Ll, Lt, Lm, or Lo

		}
		if s[i+1] == c1 && Equal(s[i:i+n], sep) {
			return i
		}
		i++
		fails++
		if fails >= 4+i>>4 && i < t {
			// Give up on IndexByte, it isn't skipping ahead
			// far enough to be better than Rabin-Karp.
			// Experiments (using IndexPeriodic) suggest
			// the cutover is about 16 byte skips.
			// TODO: if large prefixes of sep are matching
			// we should cutover at even larger average skips,

	default:
		p.errorf("register list not supported on this architecture")
	}
}

func (p *Parser) registerListX86(a *obj.Addr) {
	// Accept only [RegA-RegB] syntax.
	// Don't use p.get() to provide better error messages.

	loName := p.next().String()
	lo, ok := p.arch.Register[loName]
	if !ok {
		if loName == "EOF" {
			p.errorf("register list: expected ']', found EOF")
		} else {

pkg syscall (linux-386), const IPV6_RECVPKTINFO = 49
pkg syscall (linux-386), const IPV6_RECVRTHDR = 56
pkg syscall (linux-386), const IPV6_RECVTCLASS = 66
pkg syscall (linux-386), const IPV6_ROUTER_ALERT = 22
pkg syscall (linux-386), const IPV6_RTHDR = 57
pkg syscall (linux-386), const IPV6_RTHDRDSTOPTS = 55
pkg syscall (linux-386), const IPV6_RTHDR_LOOSE = 0
pkg syscall (linux-386), const IPV6_RTHDR_STRICT = 1

    id: what-did-you-do
    attributes:
      label: "What did you do?"
      description: "If possible, provide a recipe for reproducing the error. A complete runnable program is good. A link on [go.dev/play](https://go.dev/play) is better. A failing unit test is the best."
    validations:
      required: true
  - type: textarea
    id: actual-behavior
    attributes:
      label: "What did you see happen?"
    validations:
      required: true

pkg encoding/xml, type UnmarshalerAttr interface, UnmarshalXMLAttr(Attr) error
pkg flag, type Getter interface { Get, Set, String }
pkg flag, type Getter interface, Get() interface{}
pkg flag, type Getter interface, Set(string) error
pkg flag, type Getter interface, String() string
pkg flag, var CommandLine *FlagSet
pkg go/ast, type SliceExpr struct, Max Expr

		t.Fatal("addr2line output must have 2 lines")
	}
	funcname = f[0]
	pathAndLineNo := f[1]
	f = strings.Split(pathAndLineNo, ":")
	if runtime.GOOS == "windows" && len(f) == 3 {
		// Reattach drive letter.
		f = []string{f[0] + ":" + f[1], f[2]}
	}
	if len(f) != 2 {
		t.Fatalf("no line number found in %q", pathAndLineNo)
	}
	return funcname, f[0], f[1]
}

const symName = "cmd/addr2line.TestAddr2Line"