Go AST memo

global_function_call.go

// https://cs.opensource.google/go/x/tools/+/refs/tags/v0.27.0:go/types/typeutil/callee.go might be better

func checkGlobalFunctionCall(call *ast.CallExpr, pkg *packages.Package) (pkgPath, funcName string, ok bool) {
	switch caller := call.Fun.(type) {
	case *ast.SelectorExpr:
		// Skip if the selector is a method call.
		if sel := pkg.TypesInfo.Selections[caller]; sel != nil {
			return
		}
		ident, ok := caller.X.(*ast.Ident)
		if !ok {
			return "", "", false
		}
		pkgName, ok := pkg.TypesInfo.ObjectOf(ident).(*types.PkgName)
		if !ok {
			return "", "", false
		}
		return pkgName.Imported().Path(), caller.Sel.Name, true
	case *ast.Ident:
		// Consider the dot import.
		fn, ok := pkg.TypesInfo.ObjectOf(caller).(*types.Func)
		if !ok {
			return "", "", false
		}
		return fn.Pkg().Path(), fn.Name(), true
	default:
		return "", "", false
	}
}