runtime: remove kindNoPointers

We already have the ptrdata field in a type, which encodes exactly
the same information that kindNoPointers does.

My problem with kindNoPointers is that it often leads to
double-negative code like:

   t.kind & kindNoPointers != 0

Much clearer is:

   t.ptrdata == 0

Update #27167

Change-Id: I92307d7f018a6bbe3daca4a4abb4225e359349b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/169157
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/src/runtime/map.go b/src/runtime/map.go
index 9c25b63348..0ebbf2ae76 100644
--- a/src/runtime/map.go
+++ b/src/runtime/map.go
@@ -264,7 +264,7 @@ func (h *hmap) newoverflow(t *maptype, b *bmap) *bmap {
 		ovf = (*bmap)(newobject(t.bucket))
 	}
 	h.incrnoverflow()
-	if t.bucket.kind&kindNoPointers != 0 {
+	if t.bucket.ptrdata == 0 {
 		h.createOverflow()
 		*h.extra.overflow = append(*h.extra.overflow, ovf)
 	}
@@ -368,7 +368,7 @@ func makeBucketArray(t *maptype, b uint8, dirtyalloc unsafe.Pointer) (buckets un
 		// but may not be empty.
 		buckets = dirtyalloc
 		size := t.bucket.size * nbuckets
-		if t.bucket.kind&kindNoPointers == 0 {
+		if t.bucket.ptrdata != 0 {
 			memclrHasPointers(buckets, size)
 		} else {
 			memclrNoHeapPointers(buckets, size)
@@ -742,13 +742,13 @@ search:
 			// Only clear key if there are pointers in it.
 			if t.indirectkey() {
 				*(*unsafe.Pointer)(k) = nil
-			} else if t.key.kind&kindNoPointers == 0 {
+			} else if t.key.ptrdata != 0 {
 				memclrHasPointers(k, t.key.size)
 			}
 			v := add(unsafe.Pointer(b), dataOffset+bucketCnt*uintptr(t.keysize)+i*uintptr(t.valuesize))
 			if t.indirectvalue() {
 				*(*unsafe.Pointer)(v) = nil
-			} else if t.elem.kind&kindNoPointers == 0 {
+			} else if t.elem.ptrdata != 0 {
 				memclrHasPointers(v, t.elem.size)
 			} else {
 				memclrNoHeapPointers(v, t.elem.size)
@@ -820,7 +820,7 @@ func mapiterinit(t *maptype, h *hmap, it *hiter) {
 	// grab snapshot of bucket state
 	it.B = h.B
 	it.buckets = h.buckets
-	if t.bucket.kind&kindNoPointers != 0 {
+	if t.bucket.ptrdata == 0 {
 		// Allocate the current slice and remember pointers to both current and old.
 		// This preserves all relevant overflow buckets alive even if
 		// the table grows and/or overflow buckets are added to the table
@@ -1232,7 +1232,7 @@ func evacuate(t *maptype, h *hmap, oldbucket uintptr) {
 			}
 		}
 		// Unlink the overflow buckets & clear key/value to help GC.
-		if h.flags&oldIterator == 0 && t.bucket.kind&kindNoPointers == 0 {
+		if h.flags&oldIterator == 0 && t.bucket.ptrdata != 0 {
 			b := add(h.oldbuckets, oldbucket*uintptr(t.bucketsize))
 			// Preserve b.tophash because the evacuation
 			// state is maintained there.