gotools/go/callgraph/internal/chautil/lazy.go

// LazyCallees returns a function that maps a call site (in a function in fns)
// to its callees within fns. The set of callees is computed using the CHA algorithm,
// i.e., on the entire implements relation between interfaces and concrete types
// in fns. Please see golang.org/x/tools/go/callgraph/cha for more information.
//
// The resulting function is not concurrency safe.
func LazyCallees(fns map[*ssa.Function]bool) func(site ssa.CallInstruction) []*ssa.Function { … }