Add a test runner

This removes the need to use $OLDPWD when running tests, which means
that the builddir may be an absolute or relative directory. It also
filters out the "PASS" message on successful test runs to clean up our
output.

Change-Id: I4ab937c7a87b74fe997a47cc0311e2f357f9f7e9
diff --git a/Blueprints b/Blueprints
index 70d57db..df3ad60 100644
--- a/Blueprints
+++ b/Blueprints
@@ -125,6 +125,11 @@
 )
 
 bootstrap_core_go_binary(
+    name = "gotestrunner",
+    srcs = ["gotestrunner/gotestrunner.go"],
+)
+
+bootstrap_core_go_binary(
     name = "choosestage",
     srcs = ["choosestage/choosestage.go"],
 )
diff --git a/bootstrap/bootstrap.go b/bootstrap/bootstrap.go
index dbc4710..ed5debc 100644
--- a/bootstrap/bootstrap.go
+++ b/bootstrap/bootstrap.go
@@ -30,6 +30,7 @@
 	pctx = blueprint.NewPackageContext("github.com/google/blueprint/bootstrap")
 
 	goTestMainCmd   = pctx.StaticVariable("goTestMainCmd", filepath.Join(bootstrapDir, "bin", "gotestmain"))
+	goTestRunnerCmd = pctx.StaticVariable("goTestRunnerCmd", filepath.Join(bootstrapDir, "bin", "gotestrunner"))
 	chooseStageCmd  = pctx.StaticVariable("chooseStageCmd", filepath.Join(bootstrapDir, "bin", "choosestage"))
 	pluginGenSrcCmd = pctx.StaticVariable("pluginGenSrcCmd", filepath.Join(bootstrapDir, "bin", "loadplugins"))
 
@@ -64,7 +65,7 @@
 
 	test = pctx.StaticRule("test",
 		blueprint.RuleParams{
-			Command:     "(cd $pkgSrcDir && $$OLDPWD/$in -test.short) && touch $out",
+			Command:     "$goTestRunnerCmd -p $pkgSrcDir -f $out -- $in -test.short",
 			Description: "test $pkg",
 		},
 		"pkg", "pkgSrcDir")
@@ -111,7 +112,7 @@
 
 	docsDir = filepath.Join(bootstrapDir, "docs")
 
-	bootstrapDir = filepath.Join("$buildDir", bootstrapSubDir)
+	bootstrapDir     = filepath.Join("$buildDir", bootstrapSubDir)
 	miniBootstrapDir = filepath.Join("$buildDir", miniBootstrapSubDir)
 )
 
@@ -553,9 +554,10 @@
 	})
 
 	ctx.Build(pctx, blueprint.BuildParams{
-		Rule:    test,
-		Outputs: []string{testPassed},
-		Inputs:  []string{testFile},
+		Rule:      test,
+		Outputs:   []string{testPassed},
+		Inputs:    []string{testFile},
+		Implicits: []string{"$goTestRunnerCmd"},
 		Args: map[string]string{
 			"pkg":       pkgPath,
 			"pkgSrcDir": filepath.Dir(testFiles[0]),
diff --git a/build.ninja.in b/build.ninja.in
index a782142..751dec0 100644
--- a/build.ninja.in
+++ b/build.ninja.in
@@ -190,7 +190,7 @@
 # Variant:
 # Type:    bootstrap_core_go_binary
 # Factory: github.com/google/blueprint/bootstrap.func·005
-# Defined: Blueprints:127:1
+# Defined: Blueprints:132:1
 
 build ${g.bootstrap.buildDir}/.bootstrap/choosestage/obj/choosestage.a: $
         g.bootstrap.compile ${g.bootstrap.srcDir}/choosestage/choosestage.go | $
@@ -230,6 +230,28 @@
 default ${g.bootstrap.BinDir}/gotestmain
 
 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+# Module:  gotestrunner
+# Variant:
+# Type:    bootstrap_core_go_binary
+# Factory: github.com/google/blueprint/bootstrap.func·005
+# Defined: Blueprints:127:1
+
+build ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/gotestrunner.a: $
+        g.bootstrap.compile ${g.bootstrap.srcDir}/gotestrunner/gotestrunner.go $
+        | ${g.bootstrap.compileCmd}
+    pkgPath = gotestrunner
+default ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/gotestrunner.a
+
+build ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/a.out: $
+        g.bootstrap.link $
+        ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/gotestrunner.a | $
+        ${g.bootstrap.linkCmd}
+default ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/a.out
+build ${g.bootstrap.BinDir}/gotestrunner: g.bootstrap.cp $
+        ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/a.out
+default ${g.bootstrap.BinDir}/gotestrunner
+
+# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
 # Module:  minibp
 # Variant:
 # Type:    bootstrap_core_go_binary
@@ -279,7 +301,8 @@
         ${g.bootstrap.buildDir}/.bootstrap/primary.ninja.in.timestamp: $
         s.bootstrap.primarybp ${g.bootstrap.srcDir}/Blueprints | $
         ${g.bootstrap.BinDir}/choosestage ${g.bootstrap.BinDir}/gotestmain $
-        ${g.bootstrap.BinDir}/minibp ${g.bootstrap.srcDir}/Blueprints
+        ${g.bootstrap.BinDir}/gotestrunner ${g.bootstrap.BinDir}/minibp $
+        ${g.bootstrap.srcDir}/Blueprints
     outfile = ${g.bootstrap.buildDir}/.bootstrap/primary.ninja.in
     timestamp = ${g.bootstrap.buildDir}/.bootstrap/primary.ninja.in.timestamp
     timestampdep = ${g.bootstrap.buildDir}/.bootstrap/primary.ninja.in.timestamp.d
diff --git a/gotestrunner/gotestrunner.go b/gotestrunner/gotestrunner.go
new file mode 100644
index 0000000..20fbe1c
--- /dev/null
+++ b/gotestrunner/gotestrunner.go
@@ -0,0 +1,103 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"syscall"
+)
+
+var (
+	chdir = flag.String("p", "", "Change to a path before executing test")
+	touch = flag.String("f", "", "Write a file on success")
+)
+
+// This will copy the stdout from the test process to our stdout
+// unless it only contains "PASS\n".
+func handleStdout(stdout io.Reader) {
+	reader := bufio.NewReader(stdout)
+
+	// This is intentionally 6 instead of 5 to check for EOF
+	buf, _ := reader.Peek(6)
+	if bytes.Equal(buf, []byte("PASS\n")) {
+		return
+	}
+
+	io.Copy(os.Stdout, reader)
+}
+
+func main() {
+	flag.Parse()
+
+	if flag.NArg() == 0 {
+		fmt.Fprintln(os.Stderr, "error: must pass at least one test executable")
+		os.Exit(1)
+	}
+
+	test, err := filepath.Abs(flag.Arg(0))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: Failed to locate test binary: %s", err)
+	}
+
+	cmd := exec.Command(test, flag.Args()[1:]...)
+	if *chdir != "" {
+		cmd.Dir = *chdir
+	}
+
+	cmd.Stderr = os.Stderr
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	handleStdout(stdout)
+
+	if err = cmd.Wait(); err != nil {
+		if e, ok := err.(*exec.ExitError); ok {
+			if status, ok := e.Sys().(syscall.WaitStatus); ok && status.Exited() {
+				os.Exit(status.ExitStatus())
+			} else if status.Signaled() {
+				fmt.Fprintf(os.Stderr, "test got signal %s\n", status.Signal())
+				os.Exit(1)
+			}
+		}
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	if *touch != "" {
+		err = ioutil.WriteFile(*touch, []byte{}, 0666)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	os.Exit(0)
+}