1// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package packages_test
6
7import (
8	"bytes"
9	"io/ioutil"
10	"path/filepath"
11	"runtime"
12	"strings"
13	"testing"
14	"time"
15
16	"golang.org/x/tools/go/packages"
17)
18
19// This test loads the metadata for the standard library,
20func TestStdlibMetadata(t *testing.T) {
21	// TODO(adonovan): see if we can get away without this hack.
22	// if runtime.GOOS == "android" {
23	// 	t.Skipf("incomplete std lib on %s", runtime.GOOS)
24	// }
25
26	runtime.GC()
27	t0 := time.Now()
28	var memstats runtime.MemStats
29	runtime.ReadMemStats(&memstats)
30	alloc := memstats.Alloc
31
32	// Load, parse and type-check the program.
33	cfg := &packages.Config{Mode: packages.LoadAllSyntax}
34	pkgs, err := packages.Load(cfg, "std")
35	if err != nil {
36		t.Fatalf("failed to load metadata: %v", err)
37	}
38
39	t1 := time.Now()
40	runtime.GC()
41	runtime.ReadMemStats(&memstats)
42	runtime.KeepAlive(pkgs)
43
44	t.Logf("Loaded %d packages", len(pkgs))
45	numPkgs := len(pkgs)
46
47	want := 150 // 186 on linux, 185 on windows.
48	if numPkgs < want {
49		t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want)
50	}
51
52	t.Log("GOMAXPROCS: ", runtime.GOMAXPROCS(0))
53	t.Log("Metadata:   ", t1.Sub(t0))                          // ~800ms on 12 threads
54	t.Log("#MB:        ", int64(memstats.Alloc-alloc)/1000000) // ~1MB
55}
56
57func TestCgoOption(t *testing.T) {
58	if testing.Short() {
59		t.Skip("skipping in short mode; uses tons of memory (golang.org/issue/14113)")
60	}
61
62	// TODO(adonovan): see if we can get away without these old
63	// go/loader hacks now that we use the go list command.
64	//
65	// switch runtime.GOOS {
66	// // On these systems, the net and os/user packages don't use cgo
67	// // or the std library is incomplete (Android).
68	// case "android", "plan9", "solaris", "windows":
69	// 	t.Skipf("no cgo or incomplete std lib on %s", runtime.GOOS)
70	// }
71	// // In nocgo builds (e.g. linux-amd64-nocgo),
72	// // there is no "runtime/cgo" package,
73	// // so cgo-generated Go files will have a failing import.
74	// if !build.Default.CgoEnabled {
75	// 	return
76	// }
77
78	// Test that we can load cgo-using packages with
79	// DisableCgo=true/false, which, among other things, causes go
80	// list to select pure Go/native implementations, respectively,
81	// based on build tags.
82	//
83	// Each entry specifies a package-level object and the generic
84	// file expected to define it when cgo is disabled.
85	// When cgo is enabled, the exact file is not specified (since
86	// it varies by platform), but must differ from the generic one.
87	//
88	// The test also loads the actual file to verify that the
89	// object is indeed defined at that location.
90	for _, test := range []struct {
91		pkg, name, genericFile string
92	}{
93		{"net", "cgoLookupHost", "cgo_stub.go"},
94		{"os/user", "current", "lookup_stubs.go"},
95	} {
96		cfg := &packages.Config{Mode: packages.LoadSyntax}
97		pkgs, err := packages.Load(cfg, test.pkg)
98		if err != nil {
99			t.Errorf("Load failed: %v", err)
100			continue
101		}
102		pkg := pkgs[0]
103		obj := pkg.Types.Scope().Lookup(test.name)
104		if obj == nil {
105			t.Errorf("no object %s.%s", test.pkg, test.name)
106			continue
107		}
108		posn := pkg.Fset.Position(obj.Pos())
109		gotFile := filepath.Base(posn.Filename)
110		filesMatch := gotFile == test.genericFile
111
112		if filesMatch {
113			t.Errorf("!DisableCgo: %s found in %s, want native file",
114				obj, gotFile)
115		}
116
117		// Load the file and check the object is declared at the right place.
118		b, err := ioutil.ReadFile(posn.Filename)
119		if err != nil {
120			t.Errorf("can't read %s: %s", posn.Filename, err)
121			continue
122		}
123		line := string(bytes.Split(b, []byte("\n"))[posn.Line-1])
124		// Don't assume posn.Column is accurate.
125		if !strings.Contains(line, "func "+test.name) {
126			t.Errorf("%s: %s not declared here (looking at %q)", posn, obj, line)
127		}
128	}
129}
130