// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// This file is processed by the cover command, then a test verifies that
// all compiler directives are preserved and positioned appropriately.

//go:a

//go:b
package main

//go:c1

//go:c2
//doc
func c() {
}

//go:d1

//doc
//go:d2
type d int

//go:e1

//doc
//go:e2
type (

	// Field accesses are not permitted for now. Keep an error so
	// we can find and fix this code once the situation changes.
	return a.Value // ERROR "a.Value undefined"
	// TODO: The error below should probably be positioned on the '-'.
	// d := a /* ERROR "invalid operation: operator - not defined" */ .Value - b.Value
	// return d.Abs()
}

// The second example from the issue.
type T[P int] struct{ f P }

		err = fmt.Errorf("invalid archive header")
		return
	}
	name = strings.TrimSpace(string(hdr[:16]))
	return
}

// FindExportData positions the reader r at the beginning of the
// export data section of an underlying GC-created object/archive
// file by reading from it. The reader must be positioned at the
// start of the file before calling this function. The hdr result
// is the string before the export data, either "$$" or "$$B".

	for {
		if name, after = isMarker(data[i:]); name != "" {
			return data[:i], name, after
		}
		j := bytes.Index(data[i:], newlineMarker)
		if j < 0 {
			return fixNL(data), "", nil
		}
		i += j + 1 // positioned at start of new possible marker
	}
}

// isMarker checks whether data begins with a file marker line.
// If so, it returns the name from the line and the data after the line.

			ar.files = ar.files[:len(ar.files)-1]
			return true
		}
	}
	return false
}

// addFiles adds files to the archive. The archive is known to be
// sane and we are positioned at the end. No attempt is made
// to check for existing files.
func (ar *Archive) addFiles() {
	if len(ar.files) == 0 {
		usage()
	}
	for _, file := range ar.files {
		if verbose {

// In this mode, when the [Reader] reaches the end of the data stream,
// [Reader.Read] returns [io.EOF]. The underlying reader must implement [io.ByteReader]
// in order to be left positioned just after the gzip stream.
// To start the next stream, call z.Reset(r) followed by z.Multistream(false).
// If there is no next stream, z.Reset(r) will return [io.EOF].
func (z *Reader) Multistream(ok bool) {

			return n.Pos()
		}
	}
}

// EndPos returns the approximate end position of n in the source.
// For some nodes (*Name, *BasicLit) it returns the position immediately
// following the node; for others (*BlockStmt, *SwitchStmt, etc.) it
// returns the position of the closing '}'; and for some (*ParenExpr)
// the returned position is the end position of the last enclosed
// expression.

// dddErrPos returns the positioner for reporting an invalid ... use in a call.
func dddErrPos(call *ast.CallExpr) positioner { return atPos(call.Ellipsis) }

// argErrPos returns positioner for reporting an invalid argument count.
func argErrPos(call *ast.CallExpr) positioner { return inNode(call, call.Rparen) }

// startPos returns the start position of node n.
func startPos(n ast.Node) token.Pos { return n.Pos() }

func (p position_) String() string {
	if p.line == 0 {
		if p.filename == "" {
			return "<unknown position>"
		}
		return p.filename
	}
	if p.col == 0 {
		return fmt.Sprintf("%s:%d", p.filename, p.line)
	}
	return fmt.Sprintf("%s:%d:%d", p.filename, p.line, p.col)
}

// A PosBase represents the base for relative position information:
// At position pos, the relative position is filename:line:col.

	invalidOp  = "invalid operation: "
)

// The positioner interface is used to extract the position of type-checker errors.
type positioner interface {
	Pos() token.Pos
}

func (check *Checker) error(at positioner, code Code, msg string) {
	err := check.newError(code)
	err.addf(at, "%s", msg)
	err.report()
}

func (check *Checker) errorf(at positioner, code Code, format string, args ...any) {