| cmd/asm/internal/flags | Package flags implements top-level flags and the usage message for the assembler. |
| cmd/internal/objabi | |
| cmd/internal/src | |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| go/build/constraint | Package constraint implements parsing and evaluation of build constraint lines. |
| io | Package io provides basic interfaces to I/O primitives. |
| log | Package log implements a simple logging package. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| slices | Package slices defines various functions useful with slices of any type. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| text/scanner | Package scanner provides a scanner and tokenizer for UTF-8-encoded text. |
| unicode | Package unicode provides data and functions to test some properties of Unicode code points. |