"typeterm.go":      nil,
	"typestring.go":    nil,
	"under.go":         nil,
	"unify.go":         fixSprintf,
	"universe.go":      fixGlobalTypVarDecl,
	"util_test.go":     fixTokenPos,
	"validtype.go":     func(f *ast.File) { fixTokenPos(f); renameSelectors(f, "Trace->_Trace") },
}

// TODO(gri) We should be able to make these rewriters more configurable/composable.
//           For now this is a good starting point.

	obj   *TypeName // corresponding declared object for declared types; see above for instantiated types

	// fromRHS holds the type (on RHS of declaration) this *Named type is derived
	// from (for cycle reporting). Only used by validType, and therefore does not
	// require synchronization.
	fromRHS Type

	// information for instantiated types; nil otherwise
	inst *instance

	mu         sync.Mutex     // guards all fields below

	obj   *TypeName // corresponding declared object for declared types; see above for instantiated types

	// fromRHS holds the type (on RHS of declaration) this *Named type is derived
	// from (for cycle reporting). Only used by validType, and therefore does not
	// require synchronization.
	fromRHS Type

	// information for instantiated types; nil otherwise
	inst *instance

	mu         sync.Mutex     // guards all fields below