1 files changed, 109 insertions, 0 deletions

diff --git a/vendor/golang.org/x/tools/go/gcexportdata/gcexportdata.go b/vendor/golang.org/x/tools/go/gcexportdata/gcexportdata.go
new file mode 100644
index 0000000..f8363d8
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/gcexportdata/gcexportdata.go
@@ -0,0 +1,109 @@
+// 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.IExportData(fset, pkg)
+        if err != nil {
+                return err
+        }
+        _, err = out.Write(b)
+        return err
+}