testing: Add testing.MainStart function.

This patches in the Go 1.4 function, for convenience for
people using the Go 1.4 go tool with mainline gccgo.

From-SVN: r218700

diff --git a/libgo/go/testing/testing.go b/libgo/go/testing/testing.go
index 8078ba7cc03b2a93b08d9203e96afb1043176486..1b7360a177ec406589b220b8f7551f0350222d21 100644 (file)
--- a/libgo/go/testing/testing.go
+++ b/libgo/go/testing/testing.go
@@ -117,6 +117,26 @@
 // The entire test file is presented as the example when it contains a single
 // example function, at least one other function, type, variable, or constant
 // declaration, and no test or benchmark functions.
+//
+// Main
+//
+// It is sometimes necessary for a test program to do extra setup or teardown
+// before or after testing. It is also sometimes necessary for a test to control
+// which code runs on the main thread. To support these and other cases,
+// if a test file contains a function:
+//
+//     func TestMain(m *testing.M)
+//
+// then the generated test will call TestMain(m) instead of running the tests
+// directly. TestMain runs in the main goroutine and can do whatever setup
+// and teardown is necessary around a call to m.Run. It should then call
+// os.Exit with the result of m.Run.
+//
+// The minimal implementation of TestMain is:
+//
+//     func TestMain(m *testing.M) { os.Exit(m.Run()) }
+//
+// In effect, that is the implementation used when no TestMain is explicitly defined.
 package testing
 
 import (
@@ -426,23 +446,49 @@ func tRunner(t *T, test *InternalTest) {
 // An internal function but exported because it is cross-package; part of the implementation
 // of the "go test" command.
 func Main(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample) {
+       os.Exit(MainStart(matchString, tests, benchmarks, examples).Run())
+}
+
+// M is a type passed to a TestMain function to run the actual tests.
+type M struct {
+       matchString func(pat, str string) (bool, error)
+       tests       []InternalTest
+       benchmarks  []InternalBenchmark
+       examples    []InternalExample
+}
+
+// MainStart is meant for use by tests generated by 'go test'.
+// It is not meant to be called directly and is not subject to the Go 1 compatibility document.
+// It may change signature from release to release.
+func MainStart(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample) *M {
+       return &M{
+               matchString: matchString,
+               tests:       tests,
+               benchmarks:  benchmarks,
+               examples:    examples,
+       }
+}
+
+// Run runs the tests. It returns an exit code to pass to os.Exit.
+func (m *M) Run() int {
        flag.Parse()
        parseCpuList()
 
        before()
        startAlarm()
-       haveExamples = len(examples) > 0
-       testOk := RunTests(matchString, tests)
-       exampleOk := RunExamples(matchString, examples)
+       haveExamples = len(m.examples) > 0
+       testOk := RunTests(m.matchString, m.tests)
+       exampleOk := RunExamples(m.matchString, m.examples)
        stopAlarm()
        if !testOk || !exampleOk {
                fmt.Println("FAIL")
                after()
-               os.Exit(1)
+               return 1
        }
        fmt.Println("PASS")
-       RunBenchmarks(matchString, benchmarks)
+       RunBenchmarks(m.matchString, m.benchmarks)
        after()
+       return 0
 }
 
 func (t *T) report() {