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// Copyright 2014 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.
// TODO(andybons): add logging
// TODO(andybons): restrict memory use
// TODO(andybons): send exit code to user
package main
import (
"bytes"
"context"
"crypto/sha256"
"encoding/json"
"fmt"
"go/ast"
"go/doc"
"go/parser"
"go/token"
"io"
"io/ioutil"
stdlog "log"
"net/http"
"os"
"os/exec"
"path/filepath"
"reflect"
"runtime"
"strings"
"text/template"
"time"
"github.com/bradfitz/gomemcache/memcache"
)
const (
maxRunTime = 2 * time.Second
// progName is the program name in compiler errors
progName = "prog.go"
)
type request struct {
Body string
}
type response struct {
Errors string
Events []Event
}
func (s *server) handleCompile(w http.ResponseWriter, r *http.Request) {
var req request
// Until programs that depend on golang.org/x/tools/godoc/static/playground.js
// are updated to always send JSON, this check is in place.
if b := r.FormValue("body"); b != "" {
req.Body = b
} else if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
http.Error(w, fmt.Sprintf("error decoding request: %v", err), http.StatusBadRequest)
return
}
resp := &response{}
key := cacheKey("prog", req.Body)
if err := s.cache.Get(key, resp); err != nil {
if err != memcache.ErrCacheMiss {
s.log.Errorf("s.cache.Get(%q, &response): %v", key, err)
}
var err error
resp, err = s.compileAndRun(&req)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err := s.cache.Set(key, resp); err != nil {
s.log.Errorf("cache.Set(%q, resp): %v", key, err)
}
}
var buf bytes.Buffer
if err := json.NewEncoder(&buf).Encode(resp); err != nil {
http.Error(w, fmt.Sprintf("error encoding response: %v", err), http.StatusInternalServerError)
return
}
if _, err := io.Copy(w, &buf); err != nil {
s.log.Errorf("io.Copy(w, %+v): %v", buf, err)
return
}
}
func cacheKey(prefix, body string) string {
h := sha256.New()
io.WriteString(h, body)
return fmt.Sprintf("%s-%s-%x", prefix, runtime.Version(), h.Sum(nil))
}
// isTestFunc tells whether fn has the type of a testing function.
func isTestFunc(fn *ast.FuncDecl) bool {
if fn.Type.Results != nil && len(fn.Type.Results.List) > 0 ||
fn.Type.Params.List == nil ||
len(fn.Type.Params.List) != 1 ||
len(fn.Type.Params.List[0].Names) > 1 {
return false
}
ptr, ok := fn.Type.Params.List[0].Type.(*ast.StarExpr)
if !ok {
return false
}
// We can't easily check that the type is *testing.T
// because we don't know how testing has been imported,
// but at least check that it's *T or *something.T.
if name, ok := ptr.X.(*ast.Ident); ok && name.Name == "T" {
return true
}
if sel, ok := ptr.X.(*ast.SelectorExpr); ok && sel.Sel.Name == "T" {
return true
}
return false
}
// isTest tells whether name looks like a test (or benchmark, according to prefix).
// It is a Test (say) if there is a character after Test that is not a lower-case letter.
// We don't want TesticularCancer.
func isTest(name, prefix string) bool {
if !strings.HasPrefix(name, prefix) {
return false
}
if len(name) == len(prefix) { // "Test" is ok
return true
}
return ast.IsExported(name[len(prefix):])
}
// getTestProg returns source code that executes all valid tests and examples in src.
// If the main function is present or there are no tests or examples, it returns nil.
// getTestProg emulates the "go test" command as closely as possible.
// Benchmarks are not supported because of sandboxing.
func getTestProg(src []byte) []byte {
fset := token.NewFileSet()
// Early bail for most cases.
f, err := parser.ParseFile(fset, "main.go", src, parser.ImportsOnly)
if err != nil || f.Name.Name != "main" {
return nil
}
// importPos stores the position to inject the "testing" import declaration, if needed.
importPos := fset.Position(f.Name.End()).Offset
var testingImported bool
for _, s := range f.Imports {
if s.Path.Value == `"testing"` && s.Name == nil {
testingImported = true
break
}
}
// Parse everything and extract test names.
f, err = parser.ParseFile(fset, "main.go", src, parser.ParseComments)
if err != nil {
return nil
}
var tests []string
for _, d := range f.Decls {
n, ok := d.(*ast.FuncDecl)
if !ok {
continue
}
name := n.Name.Name
switch {
case name == "main":
// main declared as a method will not obstruct creation of our main function.
if n.Recv == nil {
return nil
}
case isTest(name, "Test") && isTestFunc(n):
tests = append(tests, name)
}
}
// Tests imply imported "testing" package in the code.
// If there is no import, bail to let the compiler produce an error.
if !testingImported && len(tests) > 0 {
return nil
}
// We emulate "go test". An example with no "Output" comment is compiled,
// but not executed. An example with no text after "Output:" is compiled,
// executed, and expected to produce no output.
var ex []*doc.Example
// exNoOutput indicates whether an example with no output is found.
// We need to compile the program containing such an example even if there are no
// other tests or examples.
exNoOutput := false
for _, e := range doc.Examples(f) {
if e.Output != "" || e.EmptyOutput {
ex = append(ex, e)
}
if e.Output == "" && !e.EmptyOutput {
exNoOutput = true
}
}
if len(tests) == 0 && len(ex) == 0 && !exNoOutput {
return nil
}
if !testingImported && (len(ex) > 0 || exNoOutput) {
// In case of the program with examples and no "testing" package imported,
// add import after "package main" without modifying line numbers.
importDecl := []byte(`;import "testing";`)
src = bytes.Join([][]byte{src[:importPos], importDecl, src[importPos:]}, nil)
}
data := struct {
Tests []string
Examples []*doc.Example
}{
tests,
ex,
}
code := new(bytes.Buffer)
if err := testTmpl.Execute(code, data); err != nil {
panic(err)
}
src = append(src, code.Bytes()...)
return src
}
var testTmpl = template.Must(template.New("main").Parse(`
func main() {
matchAll := func(t string, pat string) (bool, error) { return true, nil }
tests := []testing.InternalTest{
{{range .Tests}}
{"{{.}}", {{.}}},
{{end}}
}
examples := []testing.InternalExample{
{{range .Examples}}
{"Example{{.Name}}", Example{{.Name}}, {{printf "%q" .Output}}, {{.Unordered}}},
{{end}}
}
testing.Main(matchAll, tests, nil, examples)
}
`))
func (s *server) compileAndRun(req *request) (*response, error) {
// TODO(andybons): Add semaphore to limit number of running programs at once.
tmpDir, err := ioutil.TempDir("", "sandbox")
if err != nil {
return nil, fmt.Errorf("error creating temp directory: %v", err)
}
defer os.RemoveAll(tmpDir)
src := []byte(req.Body)
in := filepath.Join(tmpDir, "main.go")
if err := ioutil.WriteFile(in, src, 0400); err != nil {
return nil, fmt.Errorf("error creating temp file %q: %v", in, err)
}
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, in, nil, parser.PackageClauseOnly)
if err == nil && f.Name.Name != "main" {
return &response{Errors: "package name must be main"}, nil
}
var testParam string
if code := getTestProg(src); code != nil {
testParam = "-test.v"
if err := ioutil.WriteFile(in, code, 0400); err != nil {
return nil, fmt.Errorf("error creating temp file %q: %v", in, err)
}
}
exe := filepath.Join(tmpDir, "a.out")
cmd := exec.Command("go", "build", "-o", exe, in)
cmd.Env = []string{"GOOS=nacl", "GOARCH=amd64p32", "GOPATH=" + os.Getenv("GOPATH")}
if out, err := cmd.CombinedOutput(); err != nil {
if _, ok := err.(*exec.ExitError); ok {
// Return compile errors to the user.
// Rewrite compiler errors to refer to progName
// instead of '/tmp/sandbox1234/main.go'.
errs := strings.Replace(string(out), in, progName, -1)
// "go build", invoked with a file name, puts this odd
// message before any compile errors; strip it.
errs = strings.Replace(errs, "# command-line-arguments\n", "", 1)
return &response{Errors: errs}, nil
}
return nil, fmt.Errorf("error building go source: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), maxRunTime)
defer cancel()
cmd = exec.CommandContext(ctx, "sel_ldr_x86_64", "-l", "/dev/null", "-S", "-e", exe, testParam)
rec := new(Recorder)
cmd.Stdout = rec.Stdout()
cmd.Stderr = rec.Stderr()
if err := cmd.Run(); err != nil {
if ctx.Err() == context.DeadlineExceeded {
return &response{Errors: "process took too long"}, nil
}
if _, ok := err.(*exec.ExitError); !ok {
return nil, fmt.Errorf("error running sandbox: %v", err)
}
}
events, err := rec.Events()
if err != nil {
return nil, fmt.Errorf("error decoding events: %v", err)
}
return &response{Events: events}, nil
}
func (s *server) healthCheck() error {
resp, err := s.compileAndRun(&request{Body: healthProg})
if err != nil {
return err
}
if resp.Errors != "" {
return fmt.Errorf("compile error: %v", resp.Errors)
}
if len(resp.Events) != 1 || resp.Events[0].Message != "ok" {
return fmt.Errorf("unexpected output: %v", resp.Events)
}
return nil
}
const healthProg = `
package main
import "fmt"
func main() { fmt.Print("ok") }
`
func (s *server) test() {
if err := s.healthCheck(); err != nil {
stdlog.Fatal(err)
}
for _, t := range tests {
resp, err := s.compileAndRun(&request{Body: t.prog})
if err != nil {
stdlog.Fatal(err)
}
if t.wantEvents != nil {
if !reflect.DeepEqual(resp.Events, t.wantEvents) {
stdlog.Fatalf("resp.Events = %q, want %q", resp.Events, t.wantEvents)
}
continue
}
if t.errors != "" {
if resp.Errors != t.errors {
stdlog.Fatalf("resp.Errors = %q, want %q", resp.Errors, t.errors)
}
continue
}
if resp.Errors != "" {
stdlog.Fatal(resp.Errors)
}
if len(resp.Events) == 0 {
stdlog.Fatalf("unexpected output: %q, want %q", "", t.want)
}
var b strings.Builder
for _, e := range resp.Events {
b.WriteString(e.Message)
}
if !strings.Contains(b.String(), t.want) {
stdlog.Fatalf("unexpected output: %q, want %q", b.String(), t.want)
}
}
fmt.Println("OK")
}
var tests = []struct {
prog, want, errors string
wantEvents []Event
}{
{prog: `
package main
import "time"
func main() {
loc, err := time.LoadLocation("America/New_York")
if err != nil {
panic(err.Error())
}
println(loc.String())
}
`, want: "America/New_York"},
{prog: `
package main
import (
"fmt"
"time"
)
func main() {
fmt.Println(time.Now())
}
`, want: "2009-11-10 23:00:00 +0000 UTC"},
{prog: `
package main
import (
"fmt"
"time"
)
func main() {
t1 := time.Tick(time.Second * 3)
t2 := time.Tick(time.Second * 7)
t3 := time.Tick(time.Second * 11)
end := time.After(time.Second * 19)
want := "112131211"
var got []byte
for {
var c byte
select {
case <-t1:
c = '1'
case <-t2:
c = '2'
case <-t3:
c = '3'
case <-end:
if g := string(got); g != want {
fmt.Printf("got %q, want %q\n", g, want)
} else {
fmt.Println("timers fired as expected")
}
return
}
got = append(got, c)
}
}
`, want: "timers fired as expected"},
{prog: `
package main
import (
"code.google.com/p/go-tour/pic"
"code.google.com/p/go-tour/reader"
"code.google.com/p/go-tour/tree"
"code.google.com/p/go-tour/wc"
)
var (
_ = pic.Show
_ = reader.Validate
_ = tree.New
_ = wc.Test
)
func main() {
println("ok")
}
`, want: "ok"},
{prog: `
package test
func main() {
println("test")
}
`, want: "", errors: "package name must be main"},
{prog: `
package main
import (
"fmt"
"os"
"path/filepath"
)
func main() {
filepath.Walk("/", func(path string, info os.FileInfo, err error) error {
fmt.Println(path)
return nil
})
}
`, want: `/
/dev
/dev/null
/dev/random
/dev/urandom
/dev/zero
/etc
/etc/group
/etc/hosts
/etc/passwd
/etc/resolv.conf
/tmp
/usr
/usr/local
/usr/local/go
/usr/local/go/lib
/usr/local/go/lib/time
/usr/local/go/lib/time/zoneinfo.zip`},
{prog: `
package main
import "testing"
func TestSanity(t *testing.T) {
if 1+1 != 2 {
t.Error("uhh...")
}
}
`, want: `=== RUN TestSanity
--- PASS: TestSanity (0.00s)
PASS`},
{prog: `
package main
func TestSanity(t *testing.T) {
t.Error("uhh...")
}
func ExampleNotExecuted() {
// Output: it should not run
}
`, want: "", errors: "prog.go:4:20: undefined: testing\n"},
{prog: `
package main
import (
"fmt"
"testing"
)
func TestSanity(t *testing.T) {
t.Error("uhh...")
}
func main() {
fmt.Println("test")
}
`, want: "test"},
{prog: `
package main//comment
import "fmt"
func ExampleOutput() {
fmt.Println("The output")
// Output: The output
}
`, want: `=== RUN ExampleOutput
--- PASS: ExampleOutput (0.00s)
PASS`},
{prog: `
package main//comment
import "fmt"
func ExampleUnorderedOutput() {
fmt.Println("2")
fmt.Println("1")
fmt.Println("3")
// Unordered output: 3
// 2
// 1
}
`, want: `=== RUN ExampleUnorderedOutput
--- PASS: ExampleUnorderedOutput (0.00s)
PASS`},
{prog: `
package main
import "fmt"
func ExampleEmptyOutput() {
// Output:
}
func ExampleEmptyOutputFail() {
fmt.Println("1")
// Output:
}
`, want: `=== RUN ExampleEmptyOutput
--- PASS: ExampleEmptyOutput (0.00s)
=== RUN ExampleEmptyOutputFail
--- FAIL: ExampleEmptyOutputFail (0.00s)
got:
1
want:
FAIL`},
// Run program without executing this example function.
{prog: `
package main
func ExampleNoOutput() {
panic(1)
}
`, want: `testing: warning: no tests to run
PASS`},
{prog: `
package main
import "fmt"
func ExampleShouldNotRun() {
fmt.Println("The output")
// Output: The output
}
func main() {
fmt.Println("Main")
}
`, want: "Main"},
{prog: `
package main
import (
"fmt"
"os"
)
func main() {
fmt.Fprintln(os.Stdout, "A")
fmt.Fprintln(os.Stderr, "B")
fmt.Fprintln(os.Stdout, "A")
fmt.Fprintln(os.Stdout, "A")
}
`, want: "A\nB\nA\nA\n"},
// Integration test for runtime.write fake timestamps.
{prog: `
package main
import (
"fmt"
"os"
"time"
)
func main() {
fmt.Fprintln(os.Stdout, "A")
fmt.Fprintln(os.Stderr, "B")
fmt.Fprintln(os.Stdout, "A")
fmt.Fprintln(os.Stdout, "A")
time.Sleep(time.Second)
fmt.Fprintln(os.Stderr, "B")
time.Sleep(time.Second)
fmt.Fprintln(os.Stdout, "A")
}
`, wantEvents: []Event{
{"A\n", "stdout", 0},
{"B\n", "stderr", time.Nanosecond},
{"A\nA\n", "stdout", time.Nanosecond},
{"B\n", "stderr", time.Second - 2*time.Nanosecond},
{"A\n", "stdout", time.Second},
}},
}