cmd/go: split out cmd/go/internal/test

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I2d0ccdb84814537ab8b8842aa1b5f5bc0a88a0fc
Reviewed-on: https://go-review.googlesource.com/36198Reviewed-by: David Crawshaw <crawshaw@golang.org>

src/cmd/go/bug.go

@@ -6,8 +6,6 @@ package main
 
 import (
 	"bytes"
-	"cmd/go/internal/base"
-	"cmd/go/internal/cfg"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -17,6 +15,9 @@ import (
 	"regexp"
 	"runtime"
 	"strings"
+
+	"cmd/go/internal/base"
+	"cmd/go/internal/cfg"
 )
 
 var cmdBug = &base.Command{

src/cmd/go/generate.go

@@ -397,7 +397,7 @@ func (g *Generator) exec(words []string) {
 	cmd.Stderr = os.Stderr
 	// Run the command in the package directory.
 	cmd.Dir = g.dir
-	cmd.Env = mergeEnvLists(g.env, cfg.OrigEnv)
+	cmd.Env = base.MergeEnvLists(g.env, cfg.OrigEnv)
 	err := cmd.Run()
 	if err != nil {
 		g.errorf("running %q: %s", words[0], err)

src/cmd/go/internal/base/env.go

@@ -6,7 +6,7 @@ package base
 
 import "strings"
 
-// envForDir returns a copy of the environment
+// EnvForDir returns a copy of the environment
 // suitable for running in the given directory.
 // The environment is the current process's environment
 // but with an updated $PWD, so that an os.Getwd in the

src/cmd/go/test.go → src/cmd/go/internal/test/test.go

@@ -2,15 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package main
+package test
 
 import (
 	"bytes"
-	"cmd/go/internal/base"
-	"cmd/go/internal/cfg"
-	"cmd/go/internal/load"
-	"cmd/go/internal/str"
-	"cmd/go/internal/work"
 	"errors"
 	"fmt"
 	"go/ast"
@@ -30,16 +25,22 @@ import (
 	"time"
 	"unicode"
 	"unicode/utf8"
+
+	"cmd/go/internal/base"
+	"cmd/go/internal/cfg"
+	"cmd/go/internal/load"
+	"cmd/go/internal/str"
+	"cmd/go/internal/work"
 )
 
 // Break init loop.
 func init() {
-	cmdTest.Run = runTest
+	CmdTest.Run = runTest
 }
 
 const testUsage = "test [build/test flags] [packages] [build/test flags & test binary flags]"
 
-var cmdTest = &base.Command{
+var CmdTest = &base.Command{
 	CustomFlags: true,
 	UsageLine:   testUsage,
 	Short:       "test packages",
@@ -112,7 +113,15 @@ The test binary also accepts flags that control execution of the test; these
 flags are also accessible by 'go test'.
 `
 
-var helpTestflag = &base.Command{
+// Usage prints the usage message for 'go test -h' and exits.
+func Usage() {
+	os.Stderr.WriteString(testUsage + "\n\n" +
+		strings.TrimSpace(testFlag1) + "\n\n\t" +
+		strings.TrimSpace(testFlag2) + "\n")
+	os.Exit(2)
+}
+
+var HelpTestflag = &base.Command{
 	UsageLine: "testflag",
 	Short:     "description of testing flags",
 	Long: `
@@ -317,7 +326,7 @@ In the second example, the argument math is passed through to the test
 binary, instead of being interpreted as the package list.
 `
 
-var helpTestfunc = &base.Command{
+var HelpTestfunc = &base.Command{
 	UsageLine: "testfunc",
 	Short:     "description of testing functions",
 	Long: `
@@ -408,7 +417,7 @@ func runTest(cmd *base.Command, args []string) {
 	var pkgArgs []string
 	pkgArgs, testArgs = testFlags(args)
 
-	findExecCmd() // initialize cached result
+	work.FindExecCmd() // initialize cached result
 
 	work.InstrumentInit()
 	work.BuildModeInit()
@@ -1107,7 +1116,7 @@ var noTestsToRun = []byte("\ntesting: warning: no tests to run\n")
 
 // builderRunTest is the action for running a test binary.
 func builderRunTest(b *work.Builder, a *work.Action) error {
-	args := str.StringList(findExecCmd(), a.Deps[0].Target, testArgs)
+	args := str.StringList(work.FindExecCmd(), a.Deps[0].Target, testArgs)
 	a.TestOutput = new(bytes.Buffer)
 
 	if cfg.BuildN || cfg.BuildX {
@@ -1127,7 +1136,7 @@ func builderRunTest(b *work.Builder, a *work.Action) error {
 
 	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Dir = a.Package.Dir
-	cmd.Env = envForDir(cmd.Dir, cfg.OrigEnv)
+	cmd.Env = base.EnvForDir(cmd.Dir, cfg.OrigEnv)
 	var buf bytes.Buffer
 	if testStreamOutput {
 		cmd.Stdout = os.Stdout

src/cmd/go/testflag.go → src/cmd/go/internal/test/testflag.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package main
+package test
 
 import (
 	"flag"
@@ -138,7 +138,6 @@ func testFlags(args []string) (packageNames, passToTest []string) {
 		} else {
 			// Test-only flags.
 			// Arguably should be handled by f.flagValue, but aren't.
-			var err error
 			switch f.name {
 			// bool flags.
 			case "c", "i", "v", "cover":
@@ -147,10 +146,11 @@ func testFlags(args []string) (packageNames, passToTest []string) {
 				testO = value
 				testNeedBinary = true
 			case "exec":
-				execCmd, err = str.SplitQuotedFields(value)
+				xcmd, err := str.SplitQuotedFields(value)
 				if err != nil {
 					base.Fatalf("invalid flag argument for -%s: %v", f.name, err)
 				}
+				work.ExecCmd = xcmd
 			case "bench":
 				// record that we saw the flag; don't care about the value
 				testBench = true

src/cmd/go/internal/work/build.go

@@ -3622,3 +3622,28 @@ func InstrumentInit() {
 		cfg.BuildContext.BuildTags = append(cfg.BuildContext.BuildTags, "msan")
 	}
 }
+
+// ExecCmd is the command to use to run user binaries.
+// Normally it is empty, meaning run the binaries directly.
+// If cross-compiling and running on a remote system or
+// simulator, it is typically go_GOOS_GOARCH_exec, with
+// the target GOOS and GOARCH substituted.
+// The -exec flag overrides these defaults.
+var ExecCmd []string
+
+// FindExecCmd derives the value of ExecCmd to use.
+// It returns that value and leaves ExecCmd set for direct use.
+func FindExecCmd() []string {
+	if ExecCmd != nil {
+		return ExecCmd
+	}
+	ExecCmd = []string{} // avoid work the second time
+	if cfg.Goos == runtime.GOOS && cfg.Goarch == runtime.GOARCH {
+		return ExecCmd
+	}
+	path, err := exec.LookPath(fmt.Sprintf("go_%s_%s_exec", cfg.Goos, cfg.Goarch))
+	if err == nil {
+		ExecCmd = []string{path}
+	}
+	return ExecCmd
+}

src/cmd/go/main.go

@@ -16,6 +16,7 @@ import (
 	"cmd/go/internal/base"
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/help"
+	"cmd/go/internal/test"
 	"cmd/go/internal/work"
 )
 
@@ -33,7 +34,7 @@ func init() {
 		work.CmdInstall,
 		cmdList,
 		cmdRun,
-		cmdTest,
+		test.CmdTest,
 		cmdTool,
 		cmdVersion,
 		cmdVet,
@@ -45,8 +46,8 @@ func init() {
 		help.HelpEnvironment,
 		help.HelpImportPath,
 		help.HelpPackages,
-		helpTestflag,
-		helpTestfunc,
+		test.HelpTestflag,
+		test.HelpTestfunc,
 	}
 }
 
@@ -134,41 +135,8 @@ func init() {
 func mainUsage() {
 	// special case "go test -h"
 	if len(os.Args) > 1 && os.Args[1] == "test" {
-		os.Stderr.WriteString(testUsage + "\n\n" +
-			strings.TrimSpace(testFlag1) + "\n\n\t" +
-			strings.TrimSpace(testFlag2) + "\n")
-		os.Exit(2)
+		test.Usage()
 	}
 	help.PrintUsage(os.Stderr)
 	os.Exit(2)
 }
-
-// envForDir returns a copy of the environment
-// suitable for running in the given directory.
-// The environment is the current process's environment
-// but with an updated $PWD, so that an os.Getwd in the
-// child will be faster.
-func envForDir(dir string, base []string) []string {
-	// Internally we only use rooted paths, so dir is rooted.
-	// Even if dir is not rooted, no harm done.
-	return mergeEnvLists([]string{"PWD=" + dir}, base)
-}
-
-// mergeEnvLists merges the two environment lists such that
-// variables with the same name in "in" replace those in "out".
-// This always returns a newly allocated slice.
-func mergeEnvLists(in, out []string) []string {
-	out = append([]string(nil), out...)
-NextVar:
-	for _, inkv := range in {
-		k := strings.SplitAfterN(inkv, "=", 2)[0]
-		for i, outkv := range out {
-			if strings.HasPrefix(outkv, k) {
-				out[i] = inkv
-				continue NextVar
-			}
-		}
-		out = append(out, inkv)
-	}
-	return out
-}

src/cmd/go/run.go

@@ -7,8 +7,6 @@ package main
 import (
 	"fmt"
 	"os"
-	"os/exec"
-	"runtime"
 	"strings"
 
 	"cmd/go/internal/base"
@@ -18,23 +16,6 @@ import (
 	"cmd/go/internal/work"
 )
 
-var execCmd []string // -exec flag, for run and test
-
-func findExecCmd() []string {
-	if execCmd != nil {
-		return execCmd
-	}
-	execCmd = []string{} // avoid work the second time
-	if cfg.Goos == runtime.GOOS && cfg.Goarch == runtime.GOARCH {
-		return execCmd
-	}
-	path, err := exec.LookPath(fmt.Sprintf("go_%s_%s_exec", cfg.Goos, cfg.Goarch))
-	if err == nil {
-		execCmd = []string{path}
-	}
-	return execCmd
-}
-
 var cmdRun = &base.Command{
 	UsageLine: "run [build flags] [-exec xprog] gofiles... [arguments...]",
 	Short:     "compile and run Go program",
@@ -62,7 +43,7 @@ func init() {
 	cmdRun.Run = runRun // break init loop
 
 	work.AddBuildFlags(cmdRun)
-	cmdRun.Flag.Var((*base.StringsFlag)(&execCmd), "exec", "")
+	cmdRun.Flag.Var((*base.StringsFlag)(&work.ExecCmd), "exec", "")
 }
 
 func printStderr(args ...interface{}) (int, error) {
@@ -136,7 +117,7 @@ func runRun(cmd *base.Command, args []string) {
 // buildRunProgram is the action for running a binary that has already
 // been compiled. We ignore exit status.
 func buildRunProgram(b *work.Builder, a *work.Action) error {
-	cmdline := str.StringList(findExecCmd(), a.Deps[0].Target, a.Args)
+	cmdline := str.StringList(work.FindExecCmd(), a.Deps[0].Target, a.Args)
 	if cfg.BuildN || cfg.BuildX {
 		b.Showcmd("", "%s", strings.Join(cmdline, " "))
 		if cfg.BuildN {

src/cmd/go/tool.go

@@ -72,7 +72,7 @@ func runTool(cmd *base.Command, args []string) {
 		Stdout: os.Stdout,
 		Stderr: os.Stderr,
 		// Set $GOROOT, mainly for go tool dist.
-		Env: mergeEnvLists([]string{"GOROOT=" + cfg.GOROOT}, os.Environ()),
+		Env: base.MergeEnvLists([]string{"GOROOT=" + cfg.GOROOT}, os.Environ()),
 	}
 	err := toolCmd.Run()
 	if err != nil {

src/cmd/go/vcs.go

@@ -6,7 +6,6 @@ package main
 
 import (
 	"bytes"
-	"cmd/go/internal/cfg"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -19,6 +18,9 @@ import (
 	"regexp"
 	"strings"
 	"sync"
+
+	"cmd/go/internal/base"
+	"cmd/go/internal/cfg"
 )
 
 // A vcsCmd describes how to use a version control system
@@ -373,7 +375,7 @@ func (v *vcsCmd) run1(dir string, cmdline string, keyval []string, verbose bool)
 
 	cmd := exec.Command(v.cmd, args...)
 	cmd.Dir = dir
-	cmd.Env = envForDir(cmd.Dir, os.Environ())
+	cmd.Env = base.EnvForDir(cmd.Dir, os.Environ())
 	if cfg.BuildX {
 		fmt.Printf("cd %s\n", dir)
 		fmt.Printf("%s %s\n", v.cmd, strings.Join(args, " "))