From e6f8e5901625f2c77ea317a3d770c52d966b5e77 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Wed, 21 Sep 2011 17:37:50 +0000
Subject: Support nil maps.

From-SVN: r179054
---
 libgo/runtime/go-map-delete.c |  4 ++++
 libgo/runtime/go-map-index.c  |  8 ++++++++
 libgo/runtime/map.goc         | 11 ++++++-----
 3 files changed, 18 insertions(+), 5 deletions(-)

(limited to 'libgo')

diff --git a/libgo/runtime/go-map-delete.c b/libgo/runtime/go-map-delete.c
index 7a3a7b8..9b19ff1 100644
--- a/libgo/runtime/go-map-delete.c
+++ b/libgo/runtime/go-map-delete.c
@@ -9,6 +9,7 @@
 
 #include "go-alloc.h"
 #include "go-assert.h"
+#include "go-panic.h"
 #include "map.h"
 
 /* Delete the entry matching KEY from MAP.  */
@@ -25,6 +26,9 @@ __go_map_delete (struct __go_map *map, const void *key)
   size_t bucket_index;
   void **pentry;
 
+  if (map == NULL)
+    __go_panic_msg ("assignment to entry in nil map");
+
   descriptor = map->__descriptor;
 
   key_descriptor = descriptor->__map_descriptor->__key_type;
diff --git a/libgo/runtime/go-map-index.c b/libgo/runtime/go-map-index.c
index a387c4b..92a8068 100644
--- a/libgo/runtime/go-map-index.c
+++ b/libgo/runtime/go-map-index.c
@@ -9,6 +9,7 @@
 
 #include "go-alloc.h"
 #include "go-assert.h"
+#include "go-panic.h"
 #include "map.h"
 
 /* Rehash MAP to a larger size.  */
@@ -85,6 +86,13 @@ __go_map_index (struct __go_map *map, const void *key, _Bool insert)
   size_t bucket_index;
   char *entry;
 
+  if (map == NULL)
+    {
+      if (insert)
+	__go_panic_msg ("assignment to entry in nil map");
+      return NULL;
+    }
+
   descriptor = map->__descriptor;
 
   key_descriptor = descriptor->__map_descriptor->__key_type;
diff --git a/libgo/runtime/map.goc b/libgo/runtime/map.goc
index d6308cb..e19bc96 100644
--- a/libgo/runtime/map.goc
+++ b/libgo/runtime/map.goc
@@ -9,17 +9,18 @@ package runtime
 typedef unsigned char byte;
 typedef _Bool bool;
 
-typedef struct __go_map hmap;
+typedef struct __go_map_type MapType;
+typedef struct __go_map Hmap;
 typedef struct __go_hash_iter hiter;
 
 /* Access a value in a map, returning a value and a presence indicator.  */
 
-func mapaccess2(h *hmap, key *byte, val *byte) (present bool) {
+func mapaccess2(t *MapType, h *Hmap, key *byte, val *byte) (present bool) {
 	byte *mapval;
 	size_t valsize;
 
 	mapval = __go_map_index(h, key, 0);
-	valsize = h->__descriptor->__map_descriptor->__val_type->__size;
+	valsize = t->__val_type->__size;
 	if (mapval == nil) {
 		__builtin_memset(val, 0, valsize);
 		present = 0;
@@ -31,7 +32,7 @@ func mapaccess2(h *hmap, key *byte, val *byte) (present bool) {
 
 /* Optionally assign a value to a map (m[k] = v, p).  */
 
-func mapassign2(h *hmap, key *byte, val *byte, p bool) {
+func mapassign2(h *Hmap, key *byte, val *byte, p bool) {
 	if (!p) {
 		__go_map_delete(h, key);
 	} else {
@@ -46,7 +47,7 @@ func mapassign2(h *hmap, key *byte, val *byte, p bool) {
 
 /* Initialize a range over a map.  */
 
-func mapiterinit(h *hmap, it *hiter) {
+func mapiterinit(h *Hmap, it *hiter) {
 	__go_mapiterinit(h, it);
 }
 
-- 
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