misc/cgo/testgodefs: convert test from bash to Go

The bash version of the test wrote intermediate files to its testdata directory.

Updates #28387
Updates #30316
Fixes #35536

Change-Id: Ib81b547d3c43e90df713a2172c8f399fefb53c68
Reviewed-on: https://go-review.googlesource.com/c/go/+/206901
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

misc/cgo/testgodefs/test.bash

-#!/usr/bin/env bash
-
-# 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.
-
-# We are testing cgo -godefs, which translates Go files that use
-# import "C" into Go files with Go definitions of types defined in the
-# import "C" block.  Add more tests here.
-FILE_PREFIXES="anonunion issue8478 fieldtypedef"
-
-cd testdata
-
-RM=
-for FP in $FILE_PREFIXES
-do
-  go tool cgo -godefs -srcdir . ${FP}.go > ${FP}_defs.go
-  RM="${RM} ${FP}_defs.go"
-done
-
-go build -o testgodefs . && ./testgodefs
-EXIT=$?
-rm -rf _obj testgodefs ${RM}
-exit $EXIT

misc/cgo/testgodefs/testgodefs_test.go

+// Copyright 2019 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 testgodefs
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// We are testing cgo -godefs, which translates Go files that use
+// import "C" into Go files with Go definitions of types defined in the
+// import "C" block.  Add more tests here.
+var filePrefixes = []string{
+	"anonunion",
+	"issue8478",
+	"fieldtypedef",
+}
+
+func TestGoDefs(t *testing.T) {
+	testdata, err := filepath.Abs("testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gopath, err := ioutil.TempDir("", "testgodefs-gopath")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(gopath)
+
+	dir := filepath.Join(gopath, "src", "testgodefs")
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	for _, fp := range filePrefixes {
+		cmd := exec.Command("go", "tool", "cgo",
+			"-godefs",
+			"-srcdir", testdata,
+			"-objdir", dir,
+			fp+".go")
+		cmd.Stderr = new(bytes.Buffer)
+
+		out, err := cmd.Output()
+		if err != nil {
+			t.Fatalf("%s: %v\n%s", strings.Join(cmd.Args, " "), err, cmd.Stderr)
+		}
+
+		if err := ioutil.WriteFile(filepath.Join(dir, fp+"_defs.go"), out, 0644); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	main, err := ioutil.ReadFile(filepath.Join("testdata", "main.go"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), main, 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), []byte("module testgodefs\ngo 1.14\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Use 'go run' to build and run the resulting binary in a single step,
+	// instead of invoking 'go build' and the resulting binary separately, so that
+	// this test can pass on mobile builders, which do not copy artifacts back
+	// from remote invocations.
+	cmd := exec.Command("go", "run", ".")
+	cmd.Env = append(os.Environ(), "GOPATH="+gopath)
+	cmd.Dir = dir
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("%s [%s]: %v\n%s", strings.Join(cmd.Args, " "), dir, err, out)
+	}
+}

src/cmd/dist/test.go

@@ -673,15 +673,13 @@ func (t *tester) registerTests() {
 		})
 	}
 
-	if t.hasBash() && t.cgoEnabled && goos != "android" && goos != "darwin" {
-		t.registerTest("testgodefs", "../misc/cgo/testgodefs", "./test.bash")
-	}
-
 	// Don't run these tests with $GO_GCFLAGS because most of them
 	// assume that they can run "go install" with no -gcflags and not
 	// recompile the entire standard library. If make.bash ran with
 	// special -gcflags, that's not true.
 	if t.cgoEnabled && gogcflags == "" {
+		t.registerHostTest("testgodefs", "../misc/cgo/testgodefs", "misc/cgo/testgodefs", ".")
+
 		t.registerTest("testso", "../misc/cgo/testso", t.goTest(), t.timeout(600), ".")
 		t.registerTest("testsovar", "../misc/cgo/testsovar", t.goTest(), t.timeout(600), ".")
 		if t.supportedBuildmode("c-archive") {