| go/build | Package build gathers information about Go packages. |
| golang.org/x/tools/go/analysis | Package analysis defines the interface between a modular static analysis and an analysis driver program. |
| golang.org/x/tools/go/analysis/passes/internal/analysisutil | Package analysisutil defines various helper functions used by two or more packages beneath go/analysis. |
| regexp | Package regexp implements regular expression search. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |