blob: 6a97dc0c2a64a52c30291fddbb583f556ab0c473 [file] [log] [blame]
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file implements testing support.
package syntax
import (
// CommentsDo parses the given source and calls the provided handler for each
// comment or error. If the text provided to handler starts with a '/' it is
// the comment text; otherwise it is the error message.
func CommentsDo(src io.Reader, handler func(line, col uint, text string)) {
var s scanner
s.init(src, handler, comments)
for s.tok != _EOF {
// ERROR comments must start with text `ERROR "msg"` or `ERROR msg`.
// Space around "msg" or msg is ignored.
var errRx = regexp.MustCompile(`^ *ERROR *"?([^"]*)"?`)
// ErrorMap collects all comments with comment text of the form
// `ERROR "msg"` or `ERROR msg` from the given src and returns them
// as []Error lists in a map indexed by line number. The position
// for each Error is the position of the token immediately preceding
// the comment, the Error message is the message msg extracted from
// the comment, with all errors that are on the same line collected
// in a slice, in source order. If there is no preceding token (the
// `ERROR` comment appears in the beginning of the file), then the
// recorded position is unknown (line, col = 0, 0). If there are no
// ERROR comments, the result is nil.
func ErrorMap(src io.Reader) (errmap map[uint][]Error) {
// position of previous token
var base *PosBase
var prev struct{ line, col uint }
var s scanner
s.init(src, func(_, _ uint, text string) {
if text[0] != '/' {
return // error, ignore
if text[1] == '*' {
text = text[:len(text)-2] // strip trailing */
if s := errRx.FindStringSubmatch(text[2:]); len(s) == 2 {
pos := MakePos(base, prev.line, prev.col)
err := Error{pos, strings.TrimSpace(s[1])}
if errmap == nil {
errmap = make(map[uint][]Error)
errmap[prev.line] = append(errmap[prev.line], err)
}, comments)
for s.tok != _EOF {
if s.tok == _Semi && s.lit != "semicolon" {
continue // ignore automatically inserted semicolons
prev.line, prev.col = s.line, s.col