mirror of
https://github.com/go-gitea/gitea.git
synced 2024-08-27 22:57:28 +02:00
110 lines
4.3 KiB
Go
110 lines
4.3 KiB
Go
|
// Copyright 2016 The Go Authors. All rights reserved.
|
||
|
// Use of this source code is governed by a BSD-style
|
||
|
// license that can be found in the LICENSE file.
|
||
|
|
||
|
// Package gcexportdata provides functions for locating, reading, and
|
||
|
// writing export data files containing type information produced by the
|
||
|
// gc compiler. This package supports go1.7 export data format and all
|
||
|
// later versions.
|
||
|
//
|
||
|
// Although it might seem convenient for this package to live alongside
|
||
|
// go/types in the standard library, this would cause version skew
|
||
|
// problems for developer tools that use it, since they must be able to
|
||
|
// consume the outputs of the gc compiler both before and after a Go
|
||
|
// update such as from Go 1.7 to Go 1.8. Because this package lives in
|
||
|
// golang.org/x/tools, sites can update their version of this repo some
|
||
|
// time before the Go 1.8 release and rebuild and redeploy their
|
||
|
// developer tools, which will then be able to consume both Go 1.7 and
|
||
|
// Go 1.8 export data files, so they will work before and after the
|
||
|
// Go update. (See discussion at https://golang.org/issue/15651.)
|
||
|
//
|
||
|
package gcexportdata // import "golang.org/x/tools/go/gcexportdata"
|
||
|
|
||
|
import (
|
||
|
"bufio"
|
||
|
"bytes"
|
||
|
"fmt"
|
||
|
"go/token"
|
||
|
"go/types"
|
||
|
"io"
|
||
|
"io/ioutil"
|
||
|
|
||
|
"golang.org/x/tools/go/internal/gcimporter"
|
||
|
)
|
||
|
|
||
|
// Find returns the name of an object (.o) or archive (.a) file
|
||
|
// containing type information for the specified import path,
|
||
|
// using the workspace layout conventions of go/build.
|
||
|
// If no file was found, an empty filename is returned.
|
||
|
//
|
||
|
// A relative srcDir is interpreted relative to the current working directory.
|
||
|
//
|
||
|
// Find also returns the package's resolved (canonical) import path,
|
||
|
// reflecting the effects of srcDir and vendoring on importPath.
|
||
|
func Find(importPath, srcDir string) (filename, path string) {
|
||
|
return gcimporter.FindPkg(importPath, srcDir)
|
||
|
}
|
||
|
|
||
|
// NewReader returns a reader for the export data section of an object
|
||
|
// (.o) or archive (.a) file read from r. The new reader may provide
|
||
|
// additional trailing data beyond the end of the export data.
|
||
|
func NewReader(r io.Reader) (io.Reader, error) {
|
||
|
buf := bufio.NewReader(r)
|
||
|
_, err := gcimporter.FindExportData(buf)
|
||
|
// If we ever switch to a zip-like archive format with the ToC
|
||
|
// at the end, we can return the correct portion of export data,
|
||
|
// but for now we must return the entire rest of the file.
|
||
|
return buf, err
|
||
|
}
|
||
|
|
||
|
// Read reads export data from in, decodes it, and returns type
|
||
|
// information for the package.
|
||
|
// The package name is specified by path.
|
||
|
// File position information is added to fset.
|
||
|
//
|
||
|
// Read may inspect and add to the imports map to ensure that references
|
||
|
// within the export data to other packages are consistent. The caller
|
||
|
// must ensure that imports[path] does not exist, or exists but is
|
||
|
// incomplete (see types.Package.Complete), and Read inserts the
|
||
|
// resulting package into this map entry.
|
||
|
//
|
||
|
// On return, the state of the reader is undefined.
|
||
|
func Read(in io.Reader, fset *token.FileSet, imports map[string]*types.Package, path string) (*types.Package, error) {
|
||
|
data, err := ioutil.ReadAll(in)
|
||
|
if err != nil {
|
||
|
return nil, fmt.Errorf("reading export data for %q: %v", path, err)
|
||
|
}
|
||
|
|
||
|
if bytes.HasPrefix(data, []byte("!<arch>")) {
|
||
|
return nil, fmt.Errorf("can't read export data for %q directly from an archive file (call gcexportdata.NewReader first to extract export data)", path)
|
||
|
}
|
||
|
|
||
|
// The App Engine Go runtime v1.6 uses the old export data format.
|
||
|
// TODO(adonovan): delete once v1.7 has been around for a while.
|
||
|
if bytes.HasPrefix(data, []byte("package ")) {
|
||
|
return gcimporter.ImportData(imports, path, path, bytes.NewReader(data))
|
||
|
}
|
||
|
|
||
|
// The indexed export format starts with an 'i'; the older
|
||
|
// binary export format starts with a 'c', 'd', or 'v'
|
||
|
// (from "version"). Select appropriate importer.
|
||
|
if len(data) > 0 && data[0] == 'i' {
|
||
|
_, pkg, err := gcimporter.IImportData(fset, imports, data[1:], path)
|
||
|
return pkg, err
|
||
|
}
|
||
|
|
||
|
_, pkg, err := gcimporter.BImportData(fset, imports, data, path)
|
||
|
return pkg, err
|
||
|
}
|
||
|
|
||
|
// Write writes encoded type information for the specified package to out.
|
||
|
// The FileSet provides file position information for named objects.
|
||
|
func Write(out io.Writer, fset *token.FileSet, pkg *types.Package) error {
|
||
|
b, err := gcimporter.BExportData(fset, pkg)
|
||
|
if err != nil {
|
||
|
return err
|
||
|
}
|
||
|
_, err = out.Write(b)
|
||
|
return err
|
||
|
}
|