Update Go library to r60.

From-SVN: r178910

13 files changed, 700 insertions, 12 deletions

diff --git a/libgo/go/runtime/append_test.go b/libgo/go/runtime/append_test.go
new file mode 100644
index 0000000..b855222
--- /dev/null
+++ b/libgo/go/runtime/append_test.go
@@ -0,0 +1,52 @@
+// Copyright 2011 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 runtime_test
+
+import "testing"
+
+const N = 20
+
+func BenchmarkAppend(b *testing.B) {
+	b.StopTimer()
+	x := make([]int, 0, N)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		x = x[0:0]
+		for j := 0; j < N; j++ {
+			x = append(x, j)
+		}
+	}
+}
+
+func BenchmarkAppendSpecialCase(b *testing.B) {
+	b.StopTimer()
+	x := make([]int, 0, N)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		x = x[0:0]
+		for j := 0; j < N; j++ {
+			if len(x) < cap(x) {
+				x = x[:len(x)+1]
+				x[len(x)-1] = j
+			} else {
+				x = append(x, j)
+			}
+		}
+	}
+}
+
+var x []int
+
+func f() int {
+	x[:1][0] = 3
+	return 2
+}
+
+func TestSideEffectOrder(t *testing.T) {
+	x = make([]int, 0, 10)
+	x = append(x, 1, f())
+	if x[0] != 1 || x[1] != 2 {
+		t.Error("append failed: ", x[0], x[1])
+	}
+}
diff --git a/libgo/go/runtime/chan_test.go b/libgo/go/runtime/chan_test.go
new file mode 100644
index 0000000..46ddfd7
--- /dev/null
+++ b/libgo/go/runtime/chan_test.go
@@ -0,0 +1,322 @@
+// Copyright 2009 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 runtime_test
+
+import (
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"testing"
+)
+
+func TestChanSendInterface(t *testing.T) {
+	type mt struct{}
+	m := &mt{}
+	c := make(chan interface{}, 1)
+	c <- m
+	select {
+	case c <- m:
+	default:
+	}
+	select {
+	case c <- m:
+	case c <- &mt{}:
+	default:
+	}
+}
+
+func TestPseudoRandomSend(t *testing.T) {
+	n := 100
+	c := make(chan int)
+	l := make([]int, n)
+	var m sync.Mutex
+	m.Lock()
+	go func() {
+		for i := 0; i < n; i++ {
+			runtime.Gosched()
+			l[i] = <-c
+		}
+		m.Unlock()
+	}()
+	for i := 0; i < n; i++ {
+		select {
+		case c <- 0:
+		case c <- 1:
+		}
+	}
+	m.Lock() // wait
+	n0 := 0
+	n1 := 0
+	for _, i := range l {
+		n0 += (i + 1) % 2
+		n1 += i
+		if n0 > n/10 && n1 > n/10 {
+			return
+		}
+	}
+	t.Errorf("Want pseudo random, got %d zeros and %d ones", n0, n1)
+}
+
+func BenchmarkSelectUncontended(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			myc1 := make(chan int, 1)
+			myc2 := make(chan int, 1)
+			myc1 <- 0
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					select {
+					case <-myc1:
+						myc2 <- 0
+					case <-myc2:
+						myc1 <- 0
+					}
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func BenchmarkSelectContended(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	myc1 := make(chan int, procs)
+	myc2 := make(chan int, procs)
+	for p := 0; p < procs; p++ {
+		myc1 <- 0
+		go func() {
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					select {
+					case <-myc1:
+						myc2 <- 0
+					case <-myc2:
+						myc1 <- 0
+					}
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func BenchmarkSelectNonblock(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			myc1 := make(chan int)
+			myc2 := make(chan int)
+			myc3 := make(chan int, 1)
+			myc4 := make(chan int, 1)
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					select {
+					case <-myc1:
+					default:
+					}
+					select {
+					case myc2 <- 0:
+					default:
+					}
+					select {
+					case <-myc3:
+					default:
+					}
+					select {
+					case myc4 <- 0:
+					default:
+					}
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func BenchmarkChanUncontended(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			myc := make(chan int, CallsPerSched)
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					myc <- 0
+				}
+				for g := 0; g < CallsPerSched; g++ {
+					<-myc
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func BenchmarkChanContended(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	myc := make(chan int, procs*CallsPerSched)
+	for p := 0; p < procs; p++ {
+		go func() {
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					myc <- 0
+				}
+				for g := 0; g < CallsPerSched; g++ {
+					<-myc
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func BenchmarkChanSync(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := 2
+	N := int32(b.N / CallsPerSched / procs * procs)
+	c := make(chan bool, procs)
+	myc := make(chan int)
+	for p := 0; p < procs; p++ {
+		go func() {
+			for {
+				i := atomic.AddInt32(&N, -1)
+				if i < 0 {
+					break
+				}
+				for g := 0; g < CallsPerSched; g++ {
+					if i%2 == 0 {
+						<-myc
+						myc <- 0
+					} else {
+						myc <- 0
+						<-myc
+					}
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func benchmarkChanProdCons(b *testing.B, chanSize, localWork int) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, 2*procs)
+	myc := make(chan int, chanSize)
+	for p := 0; p < procs; p++ {
+		go func() {
+			foo := 0
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					for i := 0; i < localWork; i++ {
+						foo *= 2
+						foo /= 2
+					}
+					myc <- 1
+				}
+			}
+			myc <- 0
+			c <- foo == 42
+		}()
+		go func() {
+			foo := 0
+			for {
+				v := <-myc
+				if v == 0 {
+					break
+				}
+				for i := 0; i < localWork; i++ {
+					foo *= 2
+					foo /= 2
+				}
+			}
+			c <- foo == 42
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+		<-c
+	}
+}
+
+func BenchmarkChanProdCons0(b *testing.B) {
+	benchmarkChanProdCons(b, 0, 0)
+}
+
+func BenchmarkChanProdCons10(b *testing.B) {
+	benchmarkChanProdCons(b, 10, 0)
+}
+
+func BenchmarkChanProdCons100(b *testing.B) {
+	benchmarkChanProdCons(b, 100, 0)
+}
+
+func BenchmarkChanProdConsWork0(b *testing.B) {
+	benchmarkChanProdCons(b, 0, 100)
+}
+
+func BenchmarkChanProdConsWork10(b *testing.B) {
+	benchmarkChanProdCons(b, 10, 100)
+}
+
+func BenchmarkChanProdConsWork100(b *testing.B) {
+	benchmarkChanProdCons(b, 100, 100)
+}
+
+func BenchmarkChanCreation(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			for atomic.AddInt32(&N, -1) >= 0 {
+				for g := 0; g < CallsPerSched; g++ {
+					myc := make(chan int, 1)
+					myc <- 0
+					<-myc
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
diff --git a/libgo/go/runtime/closure_test.go b/libgo/go/runtime/closure_test.go
new file mode 100644
index 0000000..ea65fbd
--- /dev/null
+++ b/libgo/go/runtime/closure_test.go
@@ -0,0 +1,53 @@
+// Copyright 2011 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 runtime_test
+
+import "testing"
+
+var s int
+
+func BenchmarkCallClosure(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		s += func(ii int) int { return 2 * ii }(i)
+	}
+}
+
+func BenchmarkCallClosure1(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		j := i
+		s += func(ii int) int { return 2*ii + j }(i)
+	}
+}
+
+var ss *int
+
+func BenchmarkCallClosure2(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		j := i
+		s += func() int {
+			ss = &j
+			return 2
+		}()
+	}
+}
+
+func addr1(x int) *int {
+	return func() *int { return &x }()
+}
+
+func BenchmarkCallClosure3(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		ss = addr1(i)
+	}
+}
+
+func addr2() (x int, p *int) {
+	return 0, func() *int { return &x }()
+}
+
+func BenchmarkCallClosure4(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		_, ss = addr2()
+	}
+}
diff --git a/libgo/go/runtime/debug/stack.go b/libgo/go/runtime/debug/stack.go
index e5fae63..a533a5c 100644
--- a/libgo/go/runtime/debug/stack.go
+++ b/libgo/go/runtime/debug/stack.go
@@ -52,7 +52,7 @@ func stack() []byte {
 			if err != nil {
 				continue
 			}
-			lines = bytes.Split(data, []byte{'\n'}, -1)
+			lines = bytes.Split(data, []byte{'\n'})
 			lastFile = file
 		}
 		line-- // in stack trace, lines are 1-indexed but our array is 0-indexed
diff --git a/libgo/go/runtime/debug/stack_test.go b/libgo/go/runtime/debug/stack_test.go
index f4bdc46..94293bb 100644
--- a/libgo/go/runtime/debug/stack_test.go
+++ b/libgo/go/runtime/debug/stack_test.go
@@ -23,7 +23,7 @@ func (t T) method() []byte {
 	Don't worry much about the base levels, but check the ones in our own package.
 
 		/Users/r/go/src/pkg/runtime/debug/stack_test.go:15 (0x13878)
-			*T.ptrmethod: return Stack()
+			(*T).ptrmethod: return Stack()
 		/Users/r/go/src/pkg/runtime/debug/stack_test.go:18 (0x138dd)
 			T.method: return t.ptrmethod()
 		/Users/r/go/src/pkg/runtime/debug/stack_test.go:23 (0x13920)
@@ -35,12 +35,12 @@ func (t T) method() []byte {
 */
 func TestStack(t *testing.T) {
 	b := T(0).method()
-	lines := strings.Split(string(b), "\n", -1)
+	lines := strings.Split(string(b), "\n")
 	if len(lines) <= 6 {
 		t.Fatal("too few lines")
 	}
 	check(t, lines[0], "src/pkg/runtime/debug/stack_test.go")
-	check(t, lines[1], "\t*T.ptrmethod: return Stack()")
+	check(t, lines[1], "\t(*T).ptrmethod: return Stack()")
 	check(t, lines[2], "src/pkg/runtime/debug/stack_test.go")
 	check(t, lines[3], "\tT.method: return t.ptrmethod()")
 	check(t, lines[4], "src/pkg/runtime/debug/stack_test.go")
diff --git a/libgo/go/runtime/error.go b/libgo/go/runtime/error.go
index 2515722..2b5517f 100644
--- a/libgo/go/runtime/error.go
+++ b/libgo/go/runtime/error.go
@@ -131,3 +131,8 @@ func Printany(i interface{}) {
 		print("(", typestring(i), ") ", i)
 	}
 }
+
+// called from generated code
+func panicwrap(pkg, typ, meth string) {
+	panic("value method " + pkg + "." + typ + "." + meth + " called using nil *" + typ + " pointer")
+}
diff --git a/libgo/go/runtime/export_test.go b/libgo/go/runtime/export_test.go
index 58631c7..b3af221 100644
--- a/libgo/go/runtime/export_test.go
+++ b/libgo/go/runtime/export_test.go
@@ -15,3 +15,13 @@ var F32to64 = f32to64
 var Fcmp64 = fcmp64
 var Fintto64 = fintto64
 var F64toint = f64toint
+
+func entersyscall()
+func exitsyscall()
+
+/* Useless for gccgo.
+
+var Entersyscall = entersyscall
+var Exitsyscall = exitsyscall
+
+*/
diff --git a/libgo/go/runtime/mem.go b/libgo/go/runtime/mem.go
index 2fc1892..3f21306 100644
--- a/libgo/go/runtime/mem.go
+++ b/libgo/go/runtime/mem.go
@@ -52,7 +52,7 @@ type MemStatsType struct {
 	}
 }
 
-var Sizeof_C_MStats int // filled in by malloc.goc
+var Sizeof_C_MStats uintptr // filled in by malloc.goc
 
 func init() {
 	if Sizeof_C_MStats != unsafe.Sizeof(MemStats) {
@@ -62,8 +62,13 @@ func init() {
 }
 
 // MemStats holds statistics about the memory system.
-// The statistics are only approximate, as they are not interlocked on update.
+// The statistics may be out of date, as the information is
+// updated lazily from per-thread caches.
+// Use UpdateMemStats to bring the statistics up to date.
 var MemStats MemStatsType
 
+// UpdateMemStats brings MemStats up to date.
+func UpdateMemStats()
+
 // GC runs a garbage collection.
 func GC()
diff --git a/libgo/go/runtime/pprof/pprof_test.go b/libgo/go/runtime/pprof/pprof_test.go
index a060917..4486d55 100644
--- a/libgo/go/runtime/pprof/pprof_test.go
+++ b/libgo/go/runtime/pprof/pprof_test.go
@@ -43,7 +43,7 @@ func TestCPUProfile(t *testing.T) {
 	// Convert []byte to []uintptr.
 	bytes := prof.Bytes()
 	val := *(*[]uintptr)(unsafe.Pointer(&bytes))
-	val = val[:len(bytes)/unsafe.Sizeof(uintptr(0))]
+	val = val[:len(bytes)/int(unsafe.Sizeof(uintptr(0)))]
 
 	if len(val) < 10 {
 		t.Fatalf("profile too short: %#x", val)
diff --git a/libgo/go/runtime/proc_test.go b/libgo/go/runtime/proc_test.go
index a15b2d8..1d20a58 100644
--- a/libgo/go/runtime/proc_test.go
+++ b/libgo/go/runtime/proc_test.go
@@ -6,6 +6,7 @@ package runtime_test
 
 import (
 	"runtime"
+	"sync/atomic"
 	"testing"
 )
 
@@ -24,20 +25,105 @@ func TestStopTheWorldDeadlock(t *testing.T) {
 		t.Logf("skipping during short test")
 		return
 	}
-	runtime.GOMAXPROCS(3)
-	compl := make(chan int, 1)
+	maxprocs := runtime.GOMAXPROCS(3)
+	compl := make(chan bool, 2)
 	go func() {
 		for i := 0; i != 1000; i += 1 {
 			runtime.GC()
 		}
-		compl <- 0
+		compl <- true
 	}()
 	go func() {
 		for i := 0; i != 1000; i += 1 {
 			runtime.GOMAXPROCS(3)
 		}
+		compl <- true
 	}()
 	go perpetuumMobile()
 	<-compl
+	<-compl
 	stop <- true
+	runtime.GOMAXPROCS(maxprocs)
+}
+
+func stackGrowthRecursive(i int) {
+	var pad [128]uint64
+	if i != 0 && pad[0] == 0 {
+		stackGrowthRecursive(i - 1)
+	}
+}
+
+func BenchmarkStackGrowth(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			for atomic.AddInt32(&N, -1) >= 0 {
+				runtime.Gosched()
+				for g := 0; g < CallsPerSched; g++ {
+					stackGrowthRecursive(10)
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+/* These benchmarks are meaningless for gccgo.
+
+func BenchmarkSyscall(b *testing.B) {
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			for atomic.AddInt32(&N, -1) >= 0 {
+				runtime.Gosched()
+				for g := 0; g < CallsPerSched; g++ {
+					runtime.Entersyscall()
+					runtime.Exitsyscall()
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
 }
+
+func BenchmarkSyscallWork(b *testing.B) {
+	const CallsPerSched = 1000
+	const LocalWork = 100
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			foo := 42
+			for atomic.AddInt32(&N, -1) >= 0 {
+				runtime.Gosched()
+				for g := 0; g < CallsPerSched; g++ {
+					runtime.Entersyscall()
+					for i := 0; i < LocalWork; i++ {
+						foo *= 2
+						foo /= 2
+					}
+					runtime.Exitsyscall()
+				}
+			}
+			c <- foo == 42
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+*/
diff --git a/libgo/go/runtime/sema_test.go b/libgo/go/runtime/sema_test.go
new file mode 100644
index 0000000..d95bb1e
--- /dev/null
+++ b/libgo/go/runtime/sema_test.go
@@ -0,0 +1,100 @@
+// Copyright 2009 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 runtime_test
+
+import (
+	"runtime"
+	"sync/atomic"
+	"testing"
+)
+
+func BenchmarkSemaUncontended(b *testing.B) {
+	type PaddedSem struct {
+		sem uint32
+		pad [32]uint32
+	}
+	const CallsPerSched = 1000
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			sem := new(PaddedSem)
+			for atomic.AddInt32(&N, -1) >= 0 {
+				runtime.Gosched()
+				for g := 0; g < CallsPerSched; g++ {
+					runtime.Semrelease(&sem.sem)
+					runtime.Semacquire(&sem.sem)
+				}
+			}
+			c <- true
+		}()
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func benchmarkSema(b *testing.B, block, work bool) {
+	const CallsPerSched = 1000
+	const LocalWork = 100
+	procs := runtime.GOMAXPROCS(-1)
+	N := int32(b.N / CallsPerSched)
+	c := make(chan bool, procs)
+	c2 := make(chan bool, procs/2)
+	sem := uint32(0)
+	if block {
+		for p := 0; p < procs/2; p++ {
+			go func() {
+				runtime.Semacquire(&sem)
+				c2 <- true
+			}()
+		}
+	}
+	for p := 0; p < procs; p++ {
+		go func() {
+			foo := 0
+			for atomic.AddInt32(&N, -1) >= 0 {
+				runtime.Gosched()
+				for g := 0; g < CallsPerSched; g++ {
+					runtime.Semrelease(&sem)
+					if work {
+						for i := 0; i < LocalWork; i++ {
+							foo *= 2
+							foo /= 2
+						}
+					}
+					runtime.Semacquire(&sem)
+				}
+			}
+			c <- foo == 42
+			runtime.Semrelease(&sem)
+		}()
+	}
+	if block {
+		for p := 0; p < procs/2; p++ {
+			<-c2
+		}
+	}
+	for p := 0; p < procs; p++ {
+		<-c
+	}
+}
+
+func BenchmarkSemaSyntNonblock(b *testing.B) {
+	benchmarkSema(b, false, false)
+}
+
+func BenchmarkSemaSyntBlock(b *testing.B) {
+	benchmarkSema(b, true, false)
+}
+
+func BenchmarkSemaWorkNonblock(b *testing.B) {
+	benchmarkSema(b, false, true)
+}
+
+func BenchmarkSemaWorkBlock(b *testing.B) {
+	benchmarkSema(b, true, true)
+}
diff --git a/libgo/go/runtime/softfloat64.go b/libgo/go/runtime/softfloat64.go
index d9bbe5d..e0c3b7b 100644
--- a/libgo/go/runtime/softfloat64.go
+++ b/libgo/go/runtime/softfloat64.go
@@ -11,7 +11,7 @@ package runtime
 const (
 	mantbits64 uint = 52
 	expbits64  uint = 11
-	bias64     = -1<<(expbits64-1) + 1
+	bias64          = -1<<(expbits64-1) + 1
 
 	nan64 uint64 = (1<<expbits64-1)<<mantbits64 + 1
 	inf64 uint64 = (1<<expbits64 - 1) << mantbits64
@@ -19,7 +19,7 @@ const (
 
 	mantbits32 uint = 23
 	expbits32  uint = 8
-	bias32     = -1<<(expbits32-1) + 1
+	bias32          = -1<<(expbits32-1) + 1
 
 	nan32 uint32 = (1<<expbits32-1)<<mantbits32 + 1
 	inf32 uint32 = (1<<expbits32 - 1) << mantbits32
diff --git a/libgo/go/runtime/symtab_test.go b/libgo/go/runtime/symtab_test.go
new file mode 100644
index 0000000..0db63c3
--- /dev/null
+++ b/libgo/go/runtime/symtab_test.go
@@ -0,0 +1,55 @@
+// Copyright 2009 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 runtime_test
+
+import (
+	"runtime"
+	"strings"
+	"testing"
+)
+
+var _ = runtime.Caller
+var _ = strings.HasSuffix
+type _ testing.T
+
+/* runtime.Caller is not fully implemented for gccgo.
+
+func TestCaller(t *testing.T) {
+	procs := runtime.GOMAXPROCS(-1)
+	c := make(chan bool, procs)
+	for p := 0; p < procs; p++ {
+		go func() {
+			for i := 0; i < 1000; i++ {
+				testCallerFoo(t)
+			}
+			c <- true
+		}()
+		defer func() {
+			<-c
+		}()
+	}
+}
+
+func testCallerFoo(t *testing.T) {
+	testCallerBar(t)
+}
+
+func testCallerBar(t *testing.T) {
+	for i := 0; i < 2; i++ {
+		pc, file, line, ok := runtime.Caller(i)
+		f := runtime.FuncForPC(pc)
+		if !ok ||
+			!strings.HasSuffix(file, "symtab_test.go") ||
+			(i == 0 && !strings.HasSuffix(f.Name(), "testCallerBar")) ||
+			(i == 1 && !strings.HasSuffix(f.Name(), "testCallerFoo")) ||
+			line < 5 || line > 1000 ||
+			f.Entry() >= pc {
+			t.Errorf("incorrect symbol info %d: %t %d %d %s %s %d",
+				i, ok, f.Entry(), pc, f.Name(), file, line)
+		}
+	}
+}
+
+*/