runtime: store types of allocated objects

R=rsc
CC=golang-dev
https://golang.org/cl/6569057

src/pkg/runtime/hashmap.c

@@ -3,6 +3,8 @@
 // license that can be found in the LICENSE file.
 
 #include "runtime.h"
+#include "arch_GOARCH.h"
+#include "malloc.h"
 #include "hashmap.h"
 #include "type.h"
 #include "race.h"
@@ -748,6 +750,13 @@ runtime·makemap_c(MapType *typ, int64 hint)
 	h = runtime·mal(sizeof(*h));
 	h->flag |= CanFreeTable;  /* until reflect gets involved, free is okay */
 
+	if(UseSpanType) {
+		if(false) {
+			runtime·printf("makemap %S: %p\n", *typ->string, h);
+		}
+		runtime·settype(h, (uintptr)typ | TypeInfo_Map);
+	}
+
 	ksize = ROUND(key->size, sizeof(void*));
 	vsize = ROUND(val->size, sizeof(void*));
 	if(ksize > MaxData || vsize > MaxData || ksize+vsize > MaxData) {

src/pkg/runtime/iface.c

@@ -688,6 +688,7 @@ void
 reflect·unsafe_New(Eface typ, void *ret)
 {
 	Type *t;
+	uint32 flag;
 
 	// Reflect library has reinterpreted typ
 	// as its own kind of type structure.
@@ -695,10 +696,16 @@ reflect·unsafe_New(Eface typ, void *ret)
 	// type structure sits before the data pointer.
 	t = (Type*)((Eface*)typ.data-1);
 
-	if(t->kind&KindNoPointers)
-		ret = runtime·mallocgc(t->size, FlagNoPointers, 1, 1);
-	else
-		ret = runtime·mal(t->size);
+	flag = t->kind&KindNoPointers ? FlagNoPointers : 0;
+	ret = runtime·mallocgc(t->size, flag, 1, 1);
+
+	if(UseSpanType && !flag) {
+		if(false) {
+			runtime·printf("unsafe_New %S: %p\n", *t->string, ret);
+		}
+		runtime·settype(ret, (uintptr)t | TypeInfo_SingleObject);
+	}
+
 	FLUSH(&ret);
 }
 
@@ -715,9 +722,20 @@ reflect·unsafe_NewArray(Eface typ, intgo n, void *ret)
 	t = (Type*)((Eface*)typ.data-1);
 
 	size = n*t->size;
-	if(t->kind&KindNoPointers)
+	if(size == 0)
+		ret = (byte*)&runtime·zerobase;
+	else if(t->kind&KindNoPointers)
 		ret = runtime·mallocgc(size, FlagNoPointers, 1, 1);
-	else
-		ret = runtime·mal(size);
+	else {
+		ret = runtime·mallocgc(size, 0, 1, 1);
+
+		if(UseSpanType) {
+			if(false) {
+				runtime·printf("unsafe_NewArray [%D]%S: %p\n", (int64)n, *t->string, ret);
+			}
+			runtime·settype(ret, (uintptr)t | TypeInfo_Array);
+		}
+	}
+
 	FLUSH(&ret);
 }

src/pkg/runtime/malloc.goc

@@ -708,6 +708,26 @@ runtime·new(Type *typ, uint8 *ret)
 	FLUSH(&ret);
 }
 
+// same as runtime·new, but callable from C
+void*
+runtime·cnew(Type *typ)
+{
+	uint32 flag;
+	void *ret;
+
+	m->racepc = runtime·getcallerpc(&typ);
+	flag = typ->kind&KindNoPointers ? FlagNoPointers : 0;
+	ret = runtime·mallocgc(typ->size, flag, 1, 1);
+
+	if(UseSpanType && !flag) {
+		if(false) {
+			runtime·printf("new %S: %p\n", *typ->string, ret);
+		}
+		runtime·settype(ret, (uintptr)typ | TypeInfo_SingleObject);
+	}
+	return ret;
+}
+
 void*
 runtime·stackalloc(uint32 n)
 {

src/pkg/runtime/malloc.h

@@ -452,6 +452,7 @@ void	runtime·unmarkspan(void *v, uintptr size);
 bool	runtime·blockspecial(void*);
 void	runtime·setblockspecial(void*, bool);
 void	runtime·purgecachedstats(MCache*);
+void*	runtime·cnew(Type*);
 
 void	runtime·settype(void*, uintptr);
 void	runtime·settype_flush(M*, bool);
@@ -485,3 +486,6 @@ enum
 	// Enables type information at the end of blocks allocated from heap	
 	DebugTypeAtBlockEnd = 0,
 };
+
+// defined in mgc0.go
+void	runtime·gc_m_ptr(Eface*);

src/pkg/runtime/mgc0.go

@@ -0,0 +1,10 @@
+// Copyright 2012 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
+
+// Called from C. Returns the Go type *m.
+func gc_m_ptr(ret *interface{}) {
+	*ret = (*m)(nil)
+}

src/pkg/runtime/proc.c

@@ -9,6 +9,7 @@
 #include "os_GOOS.h"
 #include "stack.h"
 #include "race.h"
+#include "type.h"
 
 bool	runtime·iscgo;
 
@@ -833,8 +834,15 @@ M*
 runtime·newm(void)
 {
 	M *mp;
+	static Type *mtype;  // The Go type M
 
-	mp = runtime·malloc(sizeof(M));
+	if(mtype == nil) {
+		Eface e;
+		runtime·gc_m_ptr(&e);
+		mtype = ((PtrType*)e.type)->elem;
+	}
+
+	mp = runtime·cnew(mtype);
 	mcommoninit(mp);
 
 	if(runtime·iscgo) {

src/pkg/runtime/runtime.h

@@ -517,6 +517,7 @@ struct Panic
  * external data
  */
 extern	String	runtime·emptystring;
+extern	uintptr runtime·zerobase;
 G*	runtime·allg;
 G*	runtime·lastg;
 M*	runtime·allm;

src/pkg/runtime/slice.c

@@ -38,7 +38,7 @@ runtime·makeslice(SliceType *t, int64 len, int64 cap, Slice ret)
 // Dummy word to use as base pointer for make([]T, 0).
 // Since you cannot take the address of such a slice,
 // you can't tell that they all have the same base pointer.
-static uintptr zerobase;
+uintptr runtime·zerobase;
 
 static void
 makeslice1(SliceType *t, intgo len, intgo cap, Slice *ret)
@@ -50,12 +50,20 @@ makeslice1(SliceType *t, intgo len, intgo cap, Slice *ret)
 	ret->len = len;
 	ret->cap = cap;
 
-	if(cap == 0)
-		ret->array = (byte*)&zerobase;
+	if(size == 0)
+		ret->array = (byte*)&runtime·zerobase;
 	else if((t->elem->kind&KindNoPointers))
 		ret->array = runtime·mallocgc(size, FlagNoPointers, 1, 1);
-	else
-		ret->array = runtime·mal(size);
+	else {
+		ret->array = runtime·mallocgc(size, 0, 1, 1);
+
+		if(UseSpanType) {
+			if(false) {
+				runtime·printf("new slice [%D]%S: %p\n", (int64)cap, *t->elem->string, ret->array);
+			}
+			runtime·settype(ret->array, (uintptr)t->elem | TypeInfo_Array);
+		}
+	}
 }
 
 // appendslice(type *Type, x, y, []T) []T

src/pkg/runtime/type.h

@@ -18,6 +18,7 @@ typedef struct Method Method;
 typedef struct IMethod IMethod;
 typedef struct SliceType SliceType;
 typedef struct FuncType FuncType;
+typedef struct PtrType PtrType;
 
 // Needs to be in sync with typekind.h/CommonSize
 struct CommonType
@@ -101,3 +102,9 @@ struct FuncType
 	Slice in;
 	Slice out;
 };
+
+struct PtrType
+{
+	Type;
+	Type *elem;
+};