// Parse parses a single Go source file from src and returns the corresponding
// syntax tree. If there are errors, Parse will return the first error found,
// and a possibly partially constructed syntax tree, or nil.
//
// If errh != nil, it is called with each error encountered, and Parse will
// process as much source as possible. In this case, the returned syntax tree
// is only nil if no correct package clause was found.

// closest outer breakable statement.
func hasBreak(s syntax.Stmt, label string, implicit bool) bool {
	switch s := s.(type) {
	default:
		panic("unreachable")

	case *syntax.DeclStmt, *syntax.EmptyStmt, *syntax.ExprStmt,
		*syntax.SendStmt, *syntax.AssignStmt, *syntax.CallStmt,
		*syntax.ReturnStmt:
		// no chance

	case *syntax.LabeledStmt:
		return hasBreak(s.Stmt, label, implicit)

func endPos(n syntax.Node) syntax.Pos { return syntax.EndPos(n) }

// makeFromLiteral returns the constant value for the given literal string and kind.
func makeFromLiteral(lit string, kind syntax.LitKind) constant.Value {
	return constant.MakeFromLiteral(lit, kind2tok[kind], 0)
}

var kind2tok = [...]token.Token{
	syntax.IntLit:    token.INT,
	syntax.FloatLit:  token.FLOAT,
	syntax.ImagLit:   token.IMAG,
	syntax.RuneLit:   token.CHAR,

func cleanupOnePass(prog *onePassProg, original *syntax.Prog) {
	for ix, instOriginal := range original.Inst {
		switch instOriginal.Op {
		case syntax.InstAlt, syntax.InstAltMatch, syntax.InstRune:
		case syntax.InstCapture, syntax.InstEmptyWidth, syntax.InstNop, syntax.InstMatch, syntax.InstFail:
			prog.Inst[ix].Next = nil
		case syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
			prog.Inst[ix].Next = nil

func TestErrorCalls(t *testing.T) {
	files, err := pkgFiles(".")
	if err != nil {
		t.Fatal(err)
	}

	for _, file := range files {
		syntax.Inspect(file, func(n syntax.Node) bool {
			call, _ := n.(*syntax.CallExpr)
			if call == nil {
				return true
			}
			selx, _ := call.Fun.(*syntax.SelectorExpr)
			if selx == nil {
				return true
			}
			if !(isName(selx.X, "check") && isName(selx.Sel, "errorf")) {
				return true

import (
	"cmd/compile/internal/ir"
	"cmd/compile/internal/syntax"
)

// TODO(mdempsky): Investigate replacing with switch statements or dense arrays.

var branchOps = [...]ir.Op{
	syntax.Break:       ir.OBREAK,
	syntax.Continue:    ir.OCONTINUE,
	syntax.Fallthrough: ir.OFALL,
	syntax.Goto:        ir.OGOTO,
}

var callOps = [...]ir.Op{
	syntax.Defer: ir.ODEFER,
	syntax.Go:    ir.OGO,

{"Name":"CBNZ","Bits":"0|0|1|1|0|1|0|1|imm19:19|Rt:5","Arch":"32-bit variant","Syntax":"CBNZ <Wt>, <label>","Code":"","Alias":""},
{"Name":"CBNZ","Bits":"1|0|1|1|0|1|0|1|imm19:19|Rt:5","Arch":"64-bit variant","Syntax":"CBNZ <Xt>, <label>","Code":"","Alias":""},
{"Name":"CBZ","Bits":"0|0|1|1|0|1|0|0|imm19:19|Rt:5","Arch":"32-bit variant","Syntax":"CBZ <Wt>, <label>","Code":"","Alias":""},

		i := 0
		for i = 0; i < len(f.Syntax.Stmt); i++ {
			if _, ok := f.Syntax.Stmt[i].(*CommentBlock); !ok {
				break
			}
		}
		f.Syntax.Stmt = append(append(f.Syntax.Stmt[:i:i], stmt), f.Syntax.Stmt[i:]...)
	} else {
		f.Go.Version = version
		f.Syntax.updateLine(f.Go.Syntax, "go", version)
	}
	return nil
}

	r2 := rune(f)
	if op&syntax.EmptyEndLine != 0 {
		if r2 != '\n' && r2 >= 0 {
			return false
		}
		op &^= syntax.EmptyEndLine
	}
	if op&syntax.EmptyEndText != 0 {
		if r2 >= 0 {
			return false
		}
		op &^= syntax.EmptyEndText
	}
	if op == 0 {
		return true
	}
	if syntax.IsWordChar(r1) != syntax.IsWordChar(r2) {
		op &^= syntax.EmptyWordBoundary
	} else {
		op &^= syntax.EmptyNoWordBoundary
	}

	styp.markComplete()
}

func embeddedFieldIdent(e syntax.Expr) *syntax.Name {
	switch e := e.(type) {
	case *syntax.Name:
		return e
	case *syntax.Operation:
		if base := ptrBase(e); base != nil {
			// *T is valid, but **T is not
			if op, _ := base.(*syntax.Operation); op == nil || ptrBase(op) == nil {
				return embeddedFieldIdent(e.X)
			}
		}
	case *syntax.SelectorExpr:
		return e.Sel
	case *syntax.IndexExpr: