Store BURNTSUSHI_TOML_110 in parser and lexer

Setting a global is racy when multiple decodes are run in parallel.

Fixes #395

.github/workflows/test.yml

@@ -20,7 +20,7 @@
           "uses": "actions/checkout@v3"
         }, {
           "name": "Test",
-          "run":  "go test ./..."
+          "run":  "go test -race ./..."
         }, {
           "name": "Test on 32bit",
           "if":   "runner.os == 'Linux'",

decode_test.go

@@ -11,6 +11,7 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -1201,6 +1202,26 @@ func TestMetaKeys(t *testing.T) {
 	}
 }
 
+func TestDecodeParallel(t *testing.T) {
+	doc, err := os.ReadFile("testdata/ja-JP.toml")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var wg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			err := Unmarshal(doc, new(map[string]interface{}))
+			if err != nil {
+				t.Fatal(err)
+			}
+		}()
+	}
+	wg.Wait()
+}
+
 // errorContains checks if the error message in have contains the text in
 // want.
 //

lex.go

@@ -46,12 +46,13 @@ func (p Position) String() string {
 }
 
 type lexer struct {
-	input string
-	start int
-	pos   int
-	line  int
-	state stateFn
-	items chan item
+	input    string
+	start    int
+	pos      int
+	line     int
+	state    stateFn
+	items    chan item
+	tomlNext bool
 
 	// Allow for backing up up to 4 runes. This is necessary because TOML
 	// contains 3-rune tokens (""" and ''').
@@ -87,13 +88,14 @@ func (lx *lexer) nextItem() item {
 	}
 }
 
-func lex(input string) *lexer {
+func lex(input string, tomlNext bool) *lexer {
 	lx := &lexer{
-		input: input,
-		state: lexTop,
-		items: make(chan item, 10),
-		stack: make([]stateFn, 0, 10),
-		line:  1,
+		input:    input,
+		state:    lexTop,
+		items:    make(chan item, 10),
+		stack:    make([]stateFn, 0, 10),
+		line:     1,
+		tomlNext: tomlNext,
 	}
 	return lx
 }
@@ -408,7 +410,7 @@ func lexTableNameEnd(lx *lexer) stateFn {
 // Lexes only one part, e.g. only 'a' inside 'a.b'.
 func lexBareName(lx *lexer) stateFn {
 	r := lx.next()
-	if isBareKeyChar(r) {
+	if isBareKeyChar(r, lx.tomlNext) {
 		return lexBareName
 	}
 	lx.backup()
@@ -618,7 +620,7 @@ func lexInlineTableValue(lx *lexer) stateFn {
 	case isWhitespace(r):
 		return lexSkip(lx, lexInlineTableValue)
 	case isNL(r):
-		if tomlNext {
+		if lx.tomlNext {
 			return lexSkip(lx, lexInlineTableValue)
 		}
 		return lx.errorPrevLine(errLexInlineTableNL{})
@@ -643,7 +645,7 @@ func lexInlineTableValueEnd(lx *lexer) stateFn {
 	case isWhitespace(r):
 		return lexSkip(lx, lexInlineTableValueEnd)
 	case isNL(r):
-		if tomlNext {
+		if lx.tomlNext {
 			return lexSkip(lx, lexInlineTableValueEnd)
 		}
 		return lx.errorPrevLine(errLexInlineTableNL{})
@@ -654,7 +656,7 @@ func lexInlineTableValueEnd(lx *lexer) stateFn {
 		lx.ignore()
 		lx.skip(isWhitespace)
 		if lx.peek() == '}' {
-			if tomlNext {
+			if lx.tomlNext {
 				return lexInlineTableValueEnd
 			}
 			return lx.errorf("trailing comma not allowed in inline tables")
@@ -838,7 +840,7 @@ func lexStringEscape(lx *lexer) stateFn {
 	r := lx.next()
 	switch r {
 	case 'e':
-		if !tomlNext {
+		if !lx.tomlNext {
 			return lx.error(errLexEscape{r})
 		}
 		fallthrough
@@ -861,7 +863,7 @@ func lexStringEscape(lx *lexer) stateFn {
 	case '\\':
 		return lx.pop()
 	case 'x':
-		if !tomlNext {
+		if !lx.tomlNext {
 			return lx.error(errLexEscape{r})
 		}
 		return lexHexEscape
@@ -1258,7 +1260,7 @@ func isHexadecimal(r rune) bool {
 	return (r >= '0' && r <= '9') || (r >= 'a' && r <= 'f') || (r >= 'A' && r <= 'F')
 }
 
-func isBareKeyChar(r rune) bool {
+func isBareKeyChar(r rune, tomlNext bool) bool {
 	if tomlNext {
 		return (r >= 'A' && r <= 'Z') ||
 			(r >= 'a' && r <= 'z') ||

meta.go

@@ -106,7 +106,7 @@ func (k Key) maybeQuoted(i int) string {
 		return `""`
 	}
 	for _, c := range k[i] {
-		if !isBareKeyChar(c) {
+		if !isBareKeyChar(c, false) {
 			return `"` + dblQuotedReplacer.Replace(k[i]) + `"`
 		}
 	}

parse.go

@@ -11,13 +11,12 @@ import (
 	"github.com/BurntSushi/toml/internal"
 )
 
-var tomlNext bool
-
 type parser struct {
 	lx         *lexer
 	context    Key      // Full key for the current hash in scope.
 	currentKey string   // Base key name for everything except hashes.
 	pos        Position // Current position in the TOML file.
+	tomlNext   bool
 
 	ordered []Key // List of keys in the order that they appear in the TOML data.
 
@@ -32,8 +31,7 @@ type keyInfo struct {
 }
 
 func parse(data string) (p *parser, err error) {
-	_, ok := os.LookupEnv("BURNTSUSHI_TOML_110")
-	tomlNext = ok
+	_, tomlNext := os.LookupEnv("BURNTSUSHI_TOML_110")
 
 	defer func() {
 		if r := recover(); r != nil {
@@ -74,9 +72,10 @@ func parse(data string) (p *parser, err error) {
 	p = &parser{
 		keyInfo:   make(map[string]keyInfo),
 		mapping:   make(map[string]interface{}),
-		lx:        lex(data),
+		lx:        lex(data, tomlNext),
 		ordered:   make([]Key, 0),
 		implicits: make(map[string]struct{}),
+		tomlNext:  tomlNext,
 	}
 	for {
 		item := p.next()
@@ -361,7 +360,7 @@ func (p *parser) valueDatetime(it item) (interface{}, tomlType) {
 		err error
 	)
 	for _, dt := range dtTypes {
-		if dt.next && !tomlNext {
+		if dt.next && !p.tomlNext {
 			continue
 		}
 		t, err = time.ParseInLocation(dt.fmt, it.val, dt.zone)
@@ -764,7 +763,7 @@ func (p *parser) replaceEscapes(it item, str string) string {
 			replaced = append(replaced, rune(0x000D))
 			r += 1
 		case 'e':
-			if tomlNext {
+			if p.tomlNext {
 				replaced = append(replaced, rune(0x001B))
 				r += 1
 			}
@@ -775,7 +774,7 @@ func (p *parser) replaceEscapes(it item, str string) string {
 			replaced = append(replaced, rune(0x005C))
 			r += 1
 		case 'x':
-			if tomlNext {
+			if p.tomlNext {
 				escaped := p.asciiEscapeToUnicode(it, s[r+1:r+3])
 				replaced = append(replaced, escaped)
 				r += 3