exp/types/staging: updated gcimporter

Mostly minor changes to match the new
definitions in types.go and const.go.

R=rsc, r
CC=golang-dev
https://golang.org/cl/6506101

src/pkg/exp/types/staging/exportdata.go

+// Copyright 2011 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.
+
+// This file implements FindGcExportData.
+
+package types
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+)
+
+func readGopackHeader(r *bufio.Reader) (name string, size int, err error) {
+	// See $GOROOT/include/ar.h.
+	hdr := make([]byte, 16+12+6+6+8+10+2)
+	_, err = io.ReadFull(r, hdr)
+	if err != nil {
+		return
+	}
+	if trace {
+		fmt.Printf("header: %s", hdr)
+	}
+	s := strings.TrimSpace(string(hdr[16+12+6+6+8:][:10]))
+	size, err = strconv.Atoi(s)
+	if err != nil || hdr[len(hdr)-2] != '`' || hdr[len(hdr)-1] != '\n' {
+		err = errors.New("invalid archive header")
+		return
+	}
+	name = strings.TrimSpace(string(hdr[:16]))
+	return
+}
+
+// FindGcExportData 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.
+//
+func FindGcExportData(r *bufio.Reader) (err error) {
+	// Read first line to make sure this is an object file.
+	line, err := r.ReadSlice('\n')
+	if err != nil {
+		return
+	}
+	if string(line) == "!<arch>\n" {
+		// Archive file.  Scan to __.PKGDEF, which should
+		// be second archive entry.
+		var name string
+		var size int
+
+		// First entry should be __.GOSYMDEF.
+		// Older archives used __.SYMDEF, so allow that too.
+		// Read and discard.
+		if name, size, err = readGopackHeader(r); err != nil {
+			return
+		}
+		if name != "__.SYMDEF" && name != "__.GOSYMDEF" {
+			err = errors.New("go archive does not begin with __.SYMDEF or __.GOSYMDEF")
+			return
+		}
+		const block = 4096
+		tmp := make([]byte, block)
+		for size > 0 {
+			n := size
+			if n > block {
+				n = block
+			}
+			if _, err = io.ReadFull(r, tmp[:n]); err != nil {
+				return
+			}
+			size -= n
+		}
+
+		// Second entry should be __.PKGDEF.
+		if name, size, err = readGopackHeader(r); err != nil {
+			return
+		}
+		if name != "__.PKGDEF" {
+			err = errors.New("go archive is missing __.PKGDEF")
+			return
+		}
+
+		// Read first line of __.PKGDEF data, so that line
+		// is once again the first line of the input.
+		if line, err = r.ReadSlice('\n'); err != nil {
+			return
+		}
+	}
+
+	// Now at __.PKGDEF in archive or still at beginning of file.
+	// Either way, line should begin with "go object ".
+	if !strings.HasPrefix(string(line), "go object ") {
+		err = errors.New("not a go object file")
+		return
+	}
+
+	// Skip over object header to export data.
+	// Begins after first line with $$.
+	for line[0] != '$' {
+		if line, err = r.ReadSlice('\n'); err != nil {
+			return
+		}
+	}
+
+	return
+}

src/pkg/exp/types/staging/gcimporter_test.go

+// Copyright 2011 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 types
+
+import (
+	"go/ast"
+	"go/build"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+	"time"
+)
+
+var gcPath string // Go compiler path
+
+func init() {
+	// determine compiler
+	var gc string
+	switch runtime.GOARCH {
+	case "386":
+		gc = "8g"
+	case "amd64":
+		gc = "6g"
+	case "arm":
+		gc = "5g"
+	default:
+		gcPath = "unknown-GOARCH-compiler"
+		return
+	}
+	gcPath = filepath.Join(build.ToolDir, gc)
+}
+
+func compile(t *testing.T, dirname, filename string) string {
+	cmd := exec.Command(gcPath, filename)
+	cmd.Dir = dirname
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("%s %s failed: %s", gcPath, filename, err)
+		return ""
+	}
+	t.Logf("%s", string(out))
+	archCh, _ := build.ArchChar(runtime.GOARCH)
+	// filename should end with ".go"
+	return filepath.Join(dirname, filename[:len(filename)-2]+archCh)
+}
+
+// Use the same global imports map for all tests. The effect is
+// as if all tested packages were imported into a single package.
+var imports = make(map[string]*ast.Object)
+
+func testPath(t *testing.T, path string) bool {
+	_, err := GcImport(imports, path)
+	if err != nil {
+		t.Errorf("testPath(%s): %s", path, err)
+		return false
+	}
+	return true
+}
+
+const maxTime = 3 * time.Second
+
+func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
+	dirname := filepath.Join(runtime.GOROOT(), "pkg", runtime.GOOS+"_"+runtime.GOARCH, dir)
+	list, err := ioutil.ReadDir(dirname)
+	if err != nil {
+		t.Errorf("testDir(%s): %s", dirname, err)
+	}
+	for _, f := range list {
+		if time.Now().After(endTime) {
+			t.Log("testing time used up")
+			return
+		}
+		switch {
+		case !f.IsDir():
+			// try extensions
+			for _, ext := range pkgExts {
+				if strings.HasSuffix(f.Name(), ext) {
+					name := f.Name()[0 : len(f.Name())-len(ext)] // remove extension
+					if testPath(t, filepath.Join(dir, name)) {
+						nimports++
+					}
+				}
+			}
+		case f.IsDir():
+			nimports += testDir(t, filepath.Join(dir, f.Name()), endTime)
+		}
+	}
+	return
+}
+
+func TestGcImport(t *testing.T) {
+	// On cross-compile builds, the path will not exist.
+	// Need to use GOHOSTOS, which is not available.
+	if _, err := os.Stat(gcPath); err != nil {
+		t.Logf("skipping test: %v", err)
+		return
+	}
+
+	if outFn := compile(t, "testdata", "exports.go"); outFn != "" {
+		defer os.Remove(outFn)
+	}
+
+	nimports := 0
+	if testPath(t, "./testdata/exports") {
+		nimports++
+	}
+	nimports += testDir(t, "", time.Now().Add(maxTime)) // installed packages
+	t.Logf("tested %d imports", nimports)
+}
+
+var importedObjectTests = []struct {
+	name string
+	kind ast.ObjKind
+	typ  string
+}{
+	{"unsafe.Pointer", ast.Typ, "Pointer"},
+	{"math.Pi", ast.Con, "untyped float"},
+	{"io.Reader", ast.Typ, "interface{Read(p []byte) (n int, err error)}"},
+	{"io.ReadWriter", ast.Typ, "interface{Read(p []byte) (n int, err error); Write(p []byte) (n int, err error)}"},
+	{"math.Sin", ast.Fun, "func(x float64) (_ float64)"},
+	// TODO(gri) add more tests
+}
+
+func TestGcImportedTypes(t *testing.T) {
+	for _, test := range importedObjectTests {
+		s := strings.Split(test.name, ".")
+		if len(s) != 2 {
+			t.Fatal("inconsistent test data")
+		}
+		importPath := s[0]
+		objName := s[1]
+
+		pkg, err := GcImport(imports, importPath)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+
+		obj := pkg.Data.(*ast.Scope).Lookup(objName)
+		if obj.Kind != test.kind {
+			t.Errorf("%s: got kind = %q; want %q", test.name, obj.Kind, test.kind)
+		}
+		typ := typeString(underlying(obj.Type.(Type)))
+		if typ != test.typ {
+			t.Errorf("%s: got type = %q; want %q", test.name, typ, test.typ)
+		}
+	}
+}

src/pkg/exp/types/staging/testdata/exports.go

+// Copyright 2011 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.
+
+// This file is used to generate an object file which
+// serves as test file for gcimporter_test.go.
+
+package exports
+
+import (
+	"go/ast"
+)
+
+// Issue 3682: Correctly read dotted identifiers from export data.
+const init1 = 0
+
+func init() {}
+
+const (
+	C0 int = 0
+	C1     = 3.14159265
+	C2     = 2.718281828i
+	C3     = -123.456e-789
+	C4     = +123.456E+789
+	C5     = 1234i
+	C6     = "foo\n"
+	C7     = `bar\n`
+)
+
+type (
+	T1  int
+	T2  [10]int
+	T3  []int
+	T4  *int
+	T5  chan int
+	T6a chan<- int
+	T6b chan (<-chan int)
+	T6c chan<- (chan int)
+	T7  <-chan *ast.File
+	T8  struct{}
+	T9  struct {
+		a    int
+		b, c float32
+		d    []string `go:"tag"`
+	}
+	T10 struct {
+		T8
+		T9
+		_ *T10
+	}
+	T11 map[int]string
+	T12 interface{}
+	T13 interface {
+		m1()
+		m2(int) float32
+	}
+	T14 interface {
+		T12
+		T13
+		m3(x ...struct{}) []T9
+	}
+	T15 func()
+	T16 func(int)
+	T17 func(x int)
+	T18 func() float32
+	T19 func() (x float32)
+	T20 func(...interface{})
+	T21 struct{ next *T21 }
+	T22 struct{ link *T23 }
+	T23 struct{ link *T22 }
+	T24 *T24
+	T25 *T26
+	T26 *T27
+	T27 *T25
+	T28 func(T28) T28
+)
+
+var (
+	V0 int
+	V1 = -991.0
+)
+
+func F1()         {}
+func F2(x int)    {}
+func F3() int     { return 0 }
+func F4() float32 { return 0 }
+func F5(a, b, c int, u, v, w struct{ x, y T1 }, more ...interface{}) (p, q, r chan<- T10)
+
+func (p *T1) M1()