tpl: Sync go_templates for Go 1.18

Using Go tag go1.18 4aa1efed4853ea067d665a952eee77c52faac774

Updates #9677

tpl/internal/go_templates/texttemplate/parse/parse.go

@@ -24,14 +24,14 @@ type Tree struct {
 	Mode      Mode      // parsing mode.
 	text      string    // text parsed to create the template (or its parent)
 	// Parsing only; cleared after parse.
-	funcs      []map[string]interface{}
+	funcs      []map[string]any
 	lex        *lexer
 	token      [3]item // three-token lookahead for parser.
 	peekCount  int
 	vars       []string // variables defined at the moment.
 	treeSet    map[string]*Tree
 	actionLine int // line of left delim starting action
-	mode       Mode
+	rangeDepth int
 }
 
 // A mode value is a set of flags (or 0). Modes control parser behavior.
@@ -39,6 +39,7 @@ type Mode uint
 
 const (
 	ParseComments Mode = 1 << iota // parse comments and add them to AST
+	SkipFuncCheck                  // do not check that functions are defined
 )
 
 // Copy returns a copy of the Tree. Any parsing state is discarded.
@@ -58,7 +59,7 @@ func (t *Tree) Copy() *Tree {
 // templates described in the argument string. The top-level template will be
 // given the specified name. If an error is encountered, parsing stops and an
 // empty map is returned with the error.
-func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]interface{}) (map[string]*Tree, error) {
+func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]any) (map[string]*Tree, error) {
 	treeSet := make(map[string]*Tree)
 	t := New(name)
 	t.text = text
@@ -127,7 +128,7 @@ func (t *Tree) peekNonSpace() item {
 // Parsing.
 
 // New allocates a new parse tree with the given name.
-func New(name string, funcs ...map[string]interface{}) *Tree {
+func New(name string, funcs ...map[string]any) *Tree {
 	return &Tree{
 		Name:  name,
 		funcs: funcs,
@@ -157,7 +158,7 @@ func (t *Tree) ErrorContext(n Node) (location, context string) {
 }
 
 // errorf formats the error and terminates processing.
-func (t *Tree) errorf(format string, args ...interface{}) {
+func (t *Tree) errorf(format string, args ...any) {
 	t.Root = nil
 	format = fmt.Sprintf("template: %s:%d: %s", t.ParseName, t.token[0].line, format)
 	panic(fmt.Errorf(format, args...))
@@ -217,12 +218,14 @@ func (t *Tree) recover(errp *error) {
 }
 
 // startParse initializes the parser, using the lexer.
-func (t *Tree) startParse(funcs []map[string]interface{}, lex *lexer, treeSet map[string]*Tree) {
+func (t *Tree) startParse(funcs []map[string]any, lex *lexer, treeSet map[string]*Tree) {
 	t.Root = nil
 	t.lex = lex
 	t.vars = []string{"$"}
 	t.funcs = funcs
 	t.treeSet = treeSet
+	lex.breakOK = !t.hasFunction("break")
+	lex.continueOK = !t.hasFunction("continue")
 }
 
 // stopParse terminates parsing.
@@ -237,7 +240,7 @@ func (t *Tree) stopParse() {
 // the template for execution. If either action delimiter string is empty, the
 // default ("{{" or "}}") is used. Embedded template definitions are added to
 // the treeSet map.
-func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error) {
+func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]any) (tree *Tree, err error) {
 	defer t.recover(&err)
 	t.ParseName = t.Name
 	emitComment := t.Mode&ParseComments != 0
@@ -385,6 +388,10 @@ func (t *Tree) action() (n Node) {
 	switch token := t.nextNonSpace(); token.typ {
 	case itemBlock:
 		return t.blockControl()
+	case itemBreak:
+		return t.breakControl(token.pos, token.line)
+	case itemContinue:
+		return t.continueControl(token.pos, token.line)
 	case itemElse:
 		return t.elseControl()
 	case itemEnd:
@@ -404,6 +411,32 @@ func (t *Tree) action() (n Node) {
 	return t.newAction(token.pos, token.line, t.pipeline("command", itemRightDelim))
 }
 
+// Break:
+//	{{break}}
+// Break keyword is past.
+func (t *Tree) breakControl(pos Pos, line int) Node {
+	if token := t.next(); token.typ != itemRightDelim {
+		t.unexpected(token, "in {{break}}")
+	}
+	if t.rangeDepth == 0 {
+		t.errorf("{{break}} outside {{range}}")
+	}
+	return t.newBreak(pos, line)
+}
+
+// Continue:
+//	{{continue}}
+// Continue keyword is past.
+func (t *Tree) continueControl(pos Pos, line int) Node {
+	if token := t.next(); token.typ != itemRightDelim {
+		t.unexpected(token, "in {{continue}}")
+	}
+	if t.rangeDepth == 0 {
+		t.errorf("{{continue}} outside {{range}}")
+	}
+	return t.newContinue(pos, line)
+}
+
 // Pipeline:
 //	declarations? command ('|' command)*
 func (t *Tree) pipeline(context string, end itemType) (pipe *PipeNode) {
@@ -479,8 +512,14 @@ func (t *Tree) checkPipeline(pipe *PipeNode, context string) {
 func (t *Tree) parseControl(allowElseIf bool, context string) (pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) {
 	defer t.popVars(len(t.vars))
 	pipe = t.pipeline(context, itemRightDelim)
+	if context == "range" {
+		t.rangeDepth++
+	}
 	var next Node
 	list, next = t.itemList()
+	if context == "range" {
+		t.rangeDepth--
+	}
 	switch next.Type() {
 	case nodeEnd: //done
 	case nodeElse:
@@ -522,7 +561,8 @@ func (t *Tree) ifControl() Node {
 //	{{range pipeline}} itemList {{else}} itemList {{end}}
 // Range keyword is past.
 func (t *Tree) rangeControl() Node {
-	return t.newRange(t.parseControl(false, "range"))
+	r := t.newRange(t.parseControl(false, "range"))
+	return r
 }
 
 // With:
@@ -689,7 +729,8 @@ func (t *Tree) operand() Node {
 func (t *Tree) term() Node {
 	switch token := t.nextNonSpace(); token.typ {
 	case itemIdentifier:
-		if !t.hasFunction(token.val) {
+		checkFunc := t.Mode&SkipFuncCheck == 0
+		if checkFunc && !t.hasFunction(token.val) {
 			t.errorf("function %q not defined", token.val)
 		}
 		return NewIdentifier(token.val).SetTree(t).SetPos(token.pos)