// case *StructType:
		// case *Field:
		// case *InterfaceType:
		// case *FuncType:
		// case *MapType:
		// case *ChanType:

		// statements
		// case *EmptyStmt:
		// case *LabeledStmt:
		// case *BlockStmt:
		// case *ExprStmt:
		case *SendStmt:
			m = n.Chan
		// case *DeclStmt:
		case *AssignStmt:
			m = n.Lhs
		// case *BranchStmt:
		// case *CallStmt:
		// case *ReturnStmt:
		// case *IfStmt:

// A rewriter implements rewriting the range-over-funcs in a given function.
type rewriter struct {
	pkg   *types2.Package
	info  *types2.Info
	sig   *types2.Signature
	outer *syntax.FuncType
	body  *syntax.BlockStmt

	// References to important types and values.
	any   types2.Object
	bool  types2.Object
	int   types2.Object
	true  types2.Object
	false types2.Object

	// Branch numbering, computed as needed.

package types2

import (
	"cmd/compile/internal/syntax"
	. "internal/types/errors"
)

// labels checks correct label use in body.
func (check *Checker) labels(body *syntax.BlockStmt) {
	// set of all labels in this body
	all := NewScope(nil, body.Pos(), syntax.EndPos(body), "label")

	fwdJumps := check.blockBranches(all, nil, nil, body.List)

package types

import (
	"go/ast"
	"go/token"
	. "internal/types/errors"
)

// labels checks correct label use in body.
func (check *Checker) labels(body *ast.BlockStmt) {
	// set of all labels in this body
	all := NewScope(nil, body.Pos(), body.End(), "label")

	fwdJumps := check.blockBranches(all, nil, nil, body.List)

	// If there are any forward jumps left, no label was found for

}

// stripOutputComment finds and removes the "Output:" or "Unordered output:"
// comment from body and comments, and adjusts the body block's end position.
func stripOutputComment(body *ast.BlockStmt, comments []*ast.CommentGroup) (*ast.BlockStmt, []*ast.CommentGroup) {
	// Do nothing if there is no "Output:" or "Unordered output:" comment.
	i, last := lastComment(body, comments)
	if last == nil || !outputPrefix.MatchString(last.Text()) {

		// we inserted above.
		pos := f.fset.File(n.Body.End()).Pos(elseOffset + 4)
		switch stmt := n.Else.(type) {
		case *ast.IfStmt:
			block := &ast.BlockStmt{
				Lbrace: pos,
				List:   []ast.Stmt{stmt},
				Rbrace: stmt.End(),
			}
			n.Else = block
		case *ast.BlockStmt:
			stmt.Lbrace = pos
		default:
			panic("unexpected node type in if")
		}
		ast.Walk(f, n.Else)
		return nil
	case *ast.SelectStmt:

}

// context must be a non-empty string unless we know that p.tok == _Lbrace.
func (p *parser) blockStmt(context string) *BlockStmt {
	if trace {
		defer p.trace("blockStmt")()
	}

	s := new(BlockStmt)
	s.pos = p.pos()

	// people coming from C may forget that braces are mandatory in Go
	if !p.got(_Lbrace) {

	//     19  .  .  .  .  Params: *ast.FieldList {
	//     20  .  .  .  .  .  Opening: 3:10
	//     21  .  .  .  .  .  Closing: 3:11
	//     22  .  .  .  .  }
	//     23  .  .  .  }
	//     24  .  .  .  Body: *ast.BlockStmt {
	//     25  .  .  .  .  Lbrace: 3:13
	//     26  .  .  .  .  List: []ast.Stmt (len = 1) {
	//     27  .  .  .  .  .  0: *ast.ExprStmt {
	//     28  .  .  .  .  .  .  X: *ast.CallExpr {

	// The Scopes mapping does not contain an entry for the
	// function body ([*ast.BlockStmt]); the function's scope is
	// associated with the [*ast.FuncType].
	//
	// The following node types may appear in Scopes:
	//
	//     *ast.File
	//     *ast.FuncType
	//     *ast.TypeSpec
	//     *ast.BlockStmt
	//     *ast.IfStmt
	//     *ast.SwitchStmt
	//     *ast.TypeSwitchStmt
	//     *ast.CaseClause

	// The Scopes mapping does not contain an entry for the
	// function body ([*ast.BlockStmt]); the function's scope is
	// associated with the [*ast.FuncType].
	//
	// The following node types may appear in Scopes:
	//
	//     *syntax.File
	//     *syntax.FuncType
	//     *syntax.TypeDecl
	//     *syntax.BlockStmt
	//     *syntax.IfStmt
	//     *syntax.SwitchStmt
	//     *syntax.CaseClause