f.walk(n.Body, ctxStmt, visit)
	case *ast.SelectStmt:
		f.walk(n.Body, ctxStmt, visit)
	case *ast.ForStmt:
		f.walk(n.Init, ctxStmt, visit)
		f.walk(&n.Cond, ctxExpr, visit)
		f.walk(n.Post, ctxStmt, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.RangeStmt:
		f.walk(&n.Key, ctxExpr, visit)
		f.walk(&n.Value, ctxExpr, visit)
		f.walk(&n.X, ctxExpr, visit)
		f.walk(n.Body, ctxStmt, visit)

<p>
A "for" statement with a ForClause is also controlled by its condition, but
additionally it may specify an <i>init</i>
and a <i>post</i> statement, such as an assignment,
an increment or decrement statement. The init statement may be a
<a href="#Short_variable_declarations">short variable declaration</a>, but the post statement must not.
Variables declared by the init statement are re-used in each iteration.
</p>

<pre class="ebnf">

In an external link, cmd/link will create a temporary directory, write any
host object files found in package archives to that directory (renamed
to avoid conflicts), write the go.o file to that directory, and invoke
the host linker. The default value for the host linker is $CC, split
into fields, or else "gcc". The specific host linker command line can
be overridden using command line flags: cmd/link -extld=clang

	}
	defer func() {
		s := recover()
		if s == nil {
			t.Fatal("did not panic")
		}
		if s.(string) != "callback panic" {
			t.Fatal("wrong panic:", s)
		}
		if !lockedOSThread() {
			t.Fatal("lost lock on OS thread after panic")
		}
	}()
	nestedCall(func() { panic("callback panic") })
	panic("nestedCall returned")
}

// Callback with zero arguments used to make the stack misaligned,

	VST1.P	[V4.S4,V5.S4], 48(R1)                            // ERROR "invalid post-increment offset"
	VST1.P	[V4.S4], 8(R1)                                   // ERROR "invalid post-increment offset"
	VLD1.P	32(R1), [V8.S4, V9.S4, V10.S4]                   // ERROR "invalid post-increment offset"
	VLD1.P	48(R1), [V7.S4, V8.S4, V9.S4, V10.S4]            // ERROR "invalid post-increment offset"

<p>
A "for" statement with a ForClause is also controlled by its condition, but
additionally it may specify an <i>init</i>
and a <i>post</i> statement, such as an assignment,
an increment or decrement statement. The init statement may be a
<a href="#Short_variable_declarations">short variable declaration</a>, but the post statement must not.
</p>

<pre class="ebnf">
ForClause = [ InitStmt ] ";" [ Condition ] ";" [ PostStmt ] .

// the subslices between those separators.
// If sep is empty, SplitN splits after each UTF-8 sequence.
// The count determines the number of subslices to return:
//
//	n > 0: at most n subslices; the last subslice will be the unsplit remainder.
//	n == 0: the result is nil (zero subslices)
//	n < 0: all subslices
//
// To split around the first instance of a separator, see Cut.

	}
	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()))...)
}

// enabled reports whether the input is enabled by an ifdef, or is at the top level.

	toPatch       []Patch
	addr          []obj.Addr
	arch          *arch.Arch
	ctxt          *obj.Link
	firstProg     *obj.Prog
	lastProg      *obj.Prog
	dataAddr      map[string]int64 // Most recent address for DATA for this symbol.
	isJump        bool             // Instruction being assembled is a jump.
	allowABI      bool             // Whether ABI selectors are allowed.

// the text of the most recently returned token is, and where it was found.
// The underlying scanner elides all spaces except newline, so the input looks like a stream of
// Tokens; original spacing is lost but we don't need it.
type TokenReader interface {
	// Next returns the next token.
	Next() ScanToken
	// The following methods all refer to the most recent token returned by Next.