gc: implement nil map support
The spec has defined nil maps this way for months.
I'm behind.
R=ken2
CC=golang-dev
https://golang.org/cl/4901052
diff --git a/src/pkg/runtime/hashmap.c b/src/pkg/runtime/hashmap.c
index 179a563..0c0e3e4 100644
--- a/src/pkg/runtime/hashmap.c
+++ b/src/pkg/runtime/hashmap.c
@@ -690,13 +690,17 @@
static int32 debug = 0;
-// makemap(key, val *Type, hint uint32) (hmap *map[any]any);
+// makemap(typ *Type, hint uint32) (hmap *map[any]any);
Hmap*
-runtime·makemap_c(Type *key, Type *val, int64 hint)
+runtime·makemap_c(MapType *typ, int64 hint)
{
Hmap *h;
int32 keyalg, valalg, keysize, valsize, valsize_in_hash;
void (*data_del)(uint32, void*, void*);
+ Type *key, *val;
+
+ key = typ->key;
+ val = typ->elem;
if(hint < 0 || (int32)hint != hint)
runtime·panicstring("makemap: size out of range");
@@ -770,9 +774,9 @@
// makemap(key, val *Type, hint int64) (hmap *map[any]any);
void
-runtime·makemap(Type *key, Type *val, int64 hint, Hmap *ret)
+runtime·makemap(MapType *typ, int64 hint, Hmap *ret)
{
- ret = runtime·makemap_c(key, val, hint);
+ ret = runtime·makemap_c(typ, hint);
FLUSH(&ret);
}
@@ -781,17 +785,22 @@
void
reflect·makemap(MapType *t, Hmap *ret)
{
- ret = runtime·makemap_c(t->key, t->elem, 0);
+ ret = runtime·makemap_c(t, 0);
FLUSH(&ret);
}
void
-runtime·mapaccess(Hmap *h, byte *ak, byte *av, bool *pres)
+runtime·mapaccess(MapType *t, Hmap *h, byte *ak, byte *av, bool *pres)
{
byte *res;
+ Type *elem;
- if(h == nil)
- runtime·panicstring("lookup in nil map");
+ if(h == nil) {
+ elem = t->elem;
+ runtime·algarray[elem->alg].copy(elem->size, av, nil);
+ *pres = false;
+ return;
+ }
if(runtime·gcwaiting)
runtime·gosched();
@@ -809,18 +818,20 @@
// mapaccess1(hmap *map[any]any, key any) (val any);
#pragma textflag 7
void
-runtime·mapaccess1(Hmap *h, ...)
+runtime·mapaccess1(MapType *t, Hmap *h, ...)
{
byte *ak, *av;
bool pres;
- if(h == nil)
- runtime·panicstring("lookup in nil map");
+ if(h == nil) {
+ ak = (byte*)(&h + 1);
+ av = ak + runtime·rnd(t->key->size, Structrnd);
+ } else {
+ ak = (byte*)&h + h->ko1;
+ av = (byte*)&h + h->vo1;
+ }
- ak = (byte*)&h + h->ko1;
- av = (byte*)&h + h->vo1;
-
- runtime·mapaccess(h, ak, av, &pres);
+ runtime·mapaccess(t, h, ak, av, &pres);
if(debug) {
runtime·prints("runtime.mapaccess1: map=");
@@ -838,18 +849,21 @@
// mapaccess2(hmap *map[any]any, key any) (val any, pres bool);
#pragma textflag 7
void
-runtime·mapaccess2(Hmap *h, ...)
+runtime·mapaccess2(MapType *t, Hmap *h, ...)
{
byte *ak, *av, *ap;
- if(h == nil)
- runtime·panicstring("lookup in nil map");
+ if(h == nil) {
+ ak = (byte*)(&h + 1);
+ av = ak + runtime·rnd(t->key->size, Structrnd);
+ ap = av + t->elem->size;
+ } else {
+ ak = (byte*)&h + h->ko1;
+ av = (byte*)&h + h->vo1;
+ ap = (byte*)&h + h->po1;
+ }
- ak = (byte*)&h + h->ko1;
- av = (byte*)&h + h->vo1;
- ap = (byte*)&h + h->po1;
-
- runtime·mapaccess(h, ak, av, ap);
+ runtime·mapaccess(t, h, ak, av, ap);
if(debug) {
runtime·prints("runtime.mapaccess2: map=");
@@ -865,39 +879,39 @@
}
// For reflect:
-// func mapaccess(h map, key iword) (val iword, pres bool)
+// func mapaccess(t type, h map, key iword) (val iword, pres bool)
// where an iword is the same word an interface value would use:
// the actual data if it fits, or else a pointer to the data.
void
-reflect·mapaccess(Hmap *h, uintptr key, uintptr val, bool pres)
+reflect·mapaccess(MapType *t, Hmap *h, uintptr key, uintptr val, bool pres)
{
byte *ak, *av;
- if(h == nil)
- runtime·panicstring("lookup in nil map");
- if(h->keysize <= sizeof(key))
+ if(t->key->size <= sizeof(key))
ak = (byte*)&key;
else
ak = (byte*)key;
val = 0;
pres = false;
- if(h->valsize <= sizeof(val))
+ if(t->elem->size <= sizeof(val))
av = (byte*)&val;
else {
- av = runtime·mal(h->valsize);
+ av = runtime·mal(t->elem->size);
val = (uintptr)av;
}
- runtime·mapaccess(h, ak, av, &pres);
+ runtime·mapaccess(t, h, ak, av, &pres);
FLUSH(&val);
FLUSH(&pres);
}
void
-runtime·mapassign(Hmap *h, byte *ak, byte *av)
+runtime·mapassign(MapType *t, Hmap *h, byte *ak, byte *av)
{
byte *res;
int32 hit;
+ USED(t);
+
if(h == nil)
runtime·panicstring("assignment to entry in nil map");
@@ -931,10 +945,10 @@
}
}
-// mapassign1(hmap *map[any]any, key any, val any);
+// mapassign1(mapType *type, hmap *map[any]any, key any, val any);
#pragma textflag 7
void
-runtime·mapassign1(Hmap *h, ...)
+runtime·mapassign1(MapType *t, Hmap *h, ...)
{
byte *ak, *av;
@@ -944,13 +958,13 @@
ak = (byte*)&h + h->ko2;
av = (byte*)&h + h->vo2;
- runtime·mapassign(h, ak, av);
+ runtime·mapassign(t, h, ak, av);
}
-// mapassign2(hmap *map[any]any, key any, val any, pres bool);
+// mapassign2(mapType *type, hmap *map[any]any, key any, val any, pres bool);
#pragma textflag 7
void
-runtime·mapassign2(Hmap *h, ...)
+runtime·mapassign2(MapType *t, Hmap *h, ...)
{
byte *ak, *av, *ap;
@@ -964,7 +978,7 @@
if(*ap == false)
av = nil; // delete
- runtime·mapassign(h, ak, av);
+ runtime·mapassign(t, h, ak, av);
if(debug) {
runtime·prints("mapassign2: map=");
@@ -976,16 +990,16 @@
}
// For reflect:
-// func mapassign(h map, key, val iword, pres bool)
+// func mapassign(t type h map, key, val iword, pres bool)
// where an iword is the same word an interface value would use:
// the actual data if it fits, or else a pointer to the data.
void
-reflect·mapassign(Hmap *h, uintptr key, uintptr val, bool pres)
+reflect·mapassign(MapType *t, Hmap *h, uintptr key, uintptr val, bool pres)
{
byte *ak, *av;
if(h == nil)
- runtime·panicstring("lookup in nil map");
+ runtime·panicstring("assignment to entry in nil map");
if(h->keysize <= sizeof(key))
ak = (byte*)&key;
else
@@ -996,12 +1010,12 @@
av = (byte*)val;
if(!pres)
av = nil;
- runtime·mapassign(h, ak, av);
+ runtime·mapassign(t, h, ak, av);
}
-// mapiterinit(hmap *map[any]any, hiter *any);
+// mapiterinit(mapType *type, hmap *map[any]any, hiter *any);
void
-runtime·mapiterinit(Hmap *h, struct hash_iter *it)
+runtime·mapiterinit(MapType*, Hmap *h, struct hash_iter *it)
{
if(h == nil) {
it->data = nil;
@@ -1023,11 +1037,11 @@
// For reflect:
// func mapiterinit(h map) (it iter)
void
-reflect·mapiterinit(Hmap *h, struct hash_iter *it)
+reflect·mapiterinit(MapType *t, Hmap *h, struct hash_iter *it)
{
it = runtime·mal(sizeof *it);
FLUSH(&it);
- runtime·mapiterinit(h, it);
+ runtime·mapiterinit(t, h, it);
}
// mapiternext(hiter *any);
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index 3c503e4..9719c30 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -62,6 +62,7 @@
typedef struct Itab Itab;
typedef struct Eface Eface;
typedef struct Type Type;
+typedef struct MapType MapType;
typedef struct Defer Defer;
typedef struct Panic Panic;
typedef struct Hmap Hmap;
@@ -616,12 +617,12 @@
void runtime·procyield(uint32);
void runtime·osyield(void);
-void runtime·mapassign(Hmap*, byte*, byte*);
-void runtime·mapaccess(Hmap*, byte*, byte*, bool*);
+void runtime·mapassign(MapType*, Hmap*, byte*, byte*);
+void runtime·mapaccess(MapType*, Hmap*, byte*, byte*, bool*);
void runtime·mapiternext(struct hash_iter*);
bool runtime·mapiterkey(struct hash_iter*, void*);
void runtime·mapiterkeyvalue(struct hash_iter*, void*, void*);
-Hmap* runtime·makemap_c(Type*, Type*, int64);
+Hmap* runtime·makemap_c(MapType*, int64);
Hchan* runtime·makechan_c(Type*, int64);
void runtime·chansend(Hchan*, void*, bool*);
diff --git a/src/pkg/runtime/type.h b/src/pkg/runtime/type.h
index 1adb6dc..d406755 100644
--- a/src/pkg/runtime/type.h
+++ b/src/pkg/runtime/type.h
@@ -16,7 +16,6 @@
typedef struct InterfaceType InterfaceType;
typedef struct Method Method;
typedef struct IMethod IMethod;
-typedef struct MapType MapType;
typedef struct ChanType ChanType;
typedef struct SliceType SliceType;
typedef struct FuncType FuncType;
