Merge from trunk revision 269780.

From-SVN: r269782

4 files changed, 32 insertions, 5 deletions

diff --git a/libgo/go/runtime/mgcmark.go b/libgo/go/runtime/mgcmark.go
index 9da881e..dc5e797 100644
--- a/libgo/go/runtime/mgcmark.go
+++ b/libgo/go/runtime/mgcmark.go
@@ -1106,9 +1106,9 @@ func scanstackblockwithmap(pc, b0, n0 uintptr, ptrmask *uint8, gcw *gcWork) {
 // Preemption must be disabled.
 //go:nowritebarrier
 func shade(b uintptr) {
-	if obj, span, objIndex := findObject(b, 0, 0, true); obj != 0 {
+	if obj, span, objIndex := findObject(b, 0, 0, !usestackmaps); obj != 0 {
 		gcw := &getg().m.p.ptr().gcw
-		greyobject(obj, 0, 0, span, gcw, objIndex, true)
+		greyobject(obj, 0, 0, span, gcw, objIndex, !usestackmaps)
 	}
 }
 
diff --git a/libgo/go/runtime/mgcsweep.go b/libgo/go/runtime/mgcsweep.go
index fb5ee6a..bc53de4 100644
--- a/libgo/go/runtime/mgcsweep.go
+++ b/libgo/go/runtime/mgcsweep.go
@@ -342,8 +342,10 @@ func (s *mspan) sweep(preserve bool) bool {
 	// it is not otherwise a problem. So we disable the test for gccgo.
 	nfreedSigned := int(nfreed)
 	if nalloc > s.allocCount {
-		// print("runtime: nelems=", s.nelems, " nalloc=", nalloc, " previous allocCount=", s.allocCount, " nfreed=", nfreed, "\n")
-		// throw("sweep increased allocation count")
+		if usestackmaps {
+			print("runtime: nelems=", s.nelems, " nalloc=", nalloc, " previous allocCount=", s.allocCount, " nfreed=", nfreed, "\n")
+			throw("sweep increased allocation count")
+		}
 
 		// For gccgo, adjust the freed count as a signed number.
 		nfreedSigned = int(s.allocCount) - int(nalloc)
diff --git a/libgo/go/runtime/runtime1.go b/libgo/go/runtime/runtime1.go
index 66091ff..e2567b3 100644
--- a/libgo/go/runtime/runtime1.go
+++ b/libgo/go/runtime/runtime1.go
@@ -362,7 +362,9 @@ func parsedebugvars() {
 	// At that point, if debug.invalidptr is set, we crash.
 	// This is not a problem, assuming that M1 really is dead and
 	// the pointer we discovered to it will not be used.
-	// debug.invalidptr = 1
+	if usestackmaps {
+		debug.invalidptr = 1
+	}
 
 	for p := gogetenv("GODEBUG"); p != ""; {
 		field := ""
diff --git a/libgo/go/runtime/testdata/testprog/gc.go b/libgo/go/runtime/testdata/testprog/gc.go
index 6b308e0..629cf2f 100644
--- a/libgo/go/runtime/testdata/testprog/gc.go
+++ b/libgo/go/runtime/testdata/testprog/gc.go
@@ -18,6 +18,7 @@ func init() {
 	register("GCFairness2", GCFairness2)
 	register("GCSys", GCSys)
 	register("GCPhys", GCPhys)
+	register("DeferLiveness", DeferLiveness)
 }
 
 func GCSys() {
@@ -210,3 +211,25 @@ func GCPhys() {
 	fmt.Println("OK")
 	runtime.KeepAlive(saved)
 }
+
+// Test that defer closure is correctly scanned when the stack is scanned.
+func DeferLiveness() {
+	var x [10]int
+	escape(&x)
+	fn := func() {
+		if x[0] != 42 {
+			panic("FAIL")
+		}
+	}
+	defer fn()
+
+	x[0] = 42
+	runtime.GC()
+	runtime.GC()
+	runtime.GC()
+}
+
+//go:noinline
+func escape(x interface{}) { sink2 = x; sink2 = nil }
+
+var sink2 interface{}