gotools/internal/facts/imports.go

// importMap computes the import map for a package by traversing the
// entire exported API each of its imports.
//
// This is a workaround for the fact that we cannot access the map used
// internally by the types.Importer returned by go/importer. The entries
// in this map are the packages and objects that may be relevant to the
// current analysis unit.
//
// Packages in the map that are only indirectly imported may be
// incomplete (!pkg.Complete()).
//
// This function scales very poorly with packages' transitive object
// references, which can be more than a million for each package near
// the top of a large project. (This was a significant contributor to
// #60621.)
// TODO(adonovan): opt: compute this information more efficiently
// by obtaining it from the internals of the gcexportdata decoder.
func importMap(imports []*types.Package) map[string]*types.Package { … }