gcimporter

Documentation

Overview

Package gcimporter provides various functions for reading gc-generated object files that can be used to implement the Importer interface defined by the Go 1.5 standard library package.

Index

• func FindExportData(r *bufio.Reader) (hdr string, err error)
• func FindPkg(path, srcDir string) (filename, id string)
• func IExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error)
• func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, ...) (_ int, pkg *types.Package, err error)
• func Import(packages map[string]*types.Package, path, srcDir string, ...) (pkg *types.Package, err error)
• func ImportData(packages map[string]*types.Package, filename, id string, data io.Reader) (pkg *types.Package, err error)

Functions

func FindExportData

func FindExportData(r *bufio.Reader) (hdr string, err error)

FindExportData positions the reader r at the beginning of the export data section of an underlying GC-created object/archive file by reading from it. The reader must be positioned at the start of the file before calling this function. The hdr result is the string before the export data, either "$$" or "$$B".

func FindPkg

func FindPkg(path, srcDir string) (filename, id string)

FindPkg returns the filename and unique package id for an import path based on package information provided by build.Import (using the build.Default build.Context). A relative srcDir is interpreted relative to the current working directory. If no file was found, an empty filename is returned.

func IExportData

func IExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error)

IExportData returns the binary export data for pkg.

If no file set is provided, position info will be missing. The package path of the top-level package will not be recorded, so that calls to IImportData can override with a provided package path.

func IImportData

func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error)

IImportData imports a package from the serialized package data and returns the number of bytes consumed and a reference to the package. If the export data version is not recognized or the format is otherwise compromised, an error is returned.

func Import

func Import(packages map[string]*types.Package, path, srcDir string, lookup func(path string) (io.ReadCloser, error)) (pkg *types.Package, err error)

Import imports a gc-generated package given its import path and srcDir, adds the corresponding package object to the packages map, and returns the object. The packages map must contain all packages already imported.

func ImportData

func ImportData(packages map[string]*types.Package, filename, id string, data io.Reader) (pkg *types.Package, err error)

ImportData imports a package by reading the gc-generated export data, adds the corresponding package object to the packages map indexed by id, and returns the object.

The packages map must contains all packages already imported. The data reader position must be the beginning of the export data section. The filename is only used in error messages.

If packages[id] contains the completely imported package, that package can be used directly, and there is no need to call this function (but there is also no harm but for extra time used).