runtime: rewrite malloc in Go.

This change introduces gomallocgc, a Go clone of mallocgc.
Only a few uses have been moved over, so there are still
lots of uses from C. Many of these C uses will be moved
over to Go (e.g. in slice.goc), but probably not all.
What should remain of C's mallocgc is an open question.

LGTM=rsc, dvyukov
R=rsc, khr, dave, bradfitz, dvyukov
CC=golang-codereviews
https://golang.org/cl/108840046

5 files changed, 28 insertions, 8 deletions

diff --git a/src/cmd/api/goapi.go b/src/cmd/api/goapi.go
index 007601328c..7216f4e0ed 100644
--- a/src/cmd/api/goapi.go
+++ b/src/cmd/api/goapi.go
@@ -378,7 +378,7 @@ func (w *Walker) parseFile(dir, file string) (*ast.File, error) {
 	}
 	if w.context != nil && file == fmt.Sprintf("zruntime_defs_%s_%s.go", w.context.GOOS, w.context.GOARCH) {
 		// Just enough to keep the api checker happy.
-		src := "package runtime; type maptype struct{}; type _type struct{}; type alg struct{}"
+		src := "package runtime; type maptype struct{}; type _type struct{}; type alg struct{}; type mspan struct{}; type m struct{}; type lock struct{}"
 		f, err = parser.ParseFile(fset, filename, src, 0)
 		if err != nil {
 			log.Fatalf("incorrect generated file: %s", err)
diff --git a/src/cmd/cc/godefs.c b/src/cmd/cc/godefs.c
index 7457bd0007..3755a8fc09 100644
--- a/src/cmd/cc/godefs.c
+++ b/src/cmd/cc/godefs.c
@@ -206,16 +206,36 @@ printtypename(Type *t)
 		Bprint(&outbuf, "uint16");
 		break;
 	case TLONG:
-		Bprint(&outbuf, "int32");
+		// The 32/64-bit ambiguous types (int,uint,uintptr)
+		// are assigned a TLONG/TULONG to distinguish them
+		// from always 32-bit types which get a TINT/TUINT.
+		// (See int_x/uint_x in pkg/runtime/runtime.h.)
+		// For LONG and VLONG types, we generate the
+		// unqualified Go type when appropriate.
+		// This makes it easier to write Go code that
+		// modifies objects with autogenerated-from-C types.
+		if(ewidth[TIND] == 4)
+			Bprint(&outbuf, "int");
+		else
+			Bprint(&outbuf, "int32");
 		break;
 	case TULONG:
-		Bprint(&outbuf, "uint32");
+		if(ewidth[TIND] == 4)
+			Bprint(&outbuf, "uint");
+		else
+			Bprint(&outbuf, "uint32");
 		break;
 	case TVLONG:
-		Bprint(&outbuf, "int64");
+		if(ewidth[TIND] == 8)
+			Bprint(&outbuf, "int");
+		else
+			Bprint(&outbuf, "int64");
 		break;
 	case TUVLONG:
-		Bprint(&outbuf, "uint64");
+		if(ewidth[TIND] == 8)
+			Bprint(&outbuf, "uint");
+		else
+			Bprint(&outbuf, "uint64");
 		break;
 	case TFLOAT:
 		Bprint(&outbuf, "float32");
diff --git a/src/cmd/gc/builtin.c b/src/cmd/gc/builtin.c
index 986a1de9ac..9de934b067 100644
--- a/src/cmd/gc/builtin.c
+++ b/src/cmd/gc/builtin.c
@@ -2,7 +2,7 @@
 char *runtimeimport =
 	"package runtime\n"
 	"import runtime \"runtime\"\n"
-	"func @\"\".new (@\"\".typ·2 *byte) (? *any)\n"
+	"func @\"\".newobject (@\"\".typ·2 *byte) (? *any)\n"
 	"func @\"\".panicindex ()\n"
 	"func @\"\".panicslice ()\n"
 	"func @\"\".panicdivide ()\n"
diff --git a/src/cmd/gc/runtime.go b/src/cmd/gc/runtime.go
index 6a9e68bcb4..2f282d6a03 100644
--- a/src/cmd/gc/runtime.go
+++ b/src/cmd/gc/runtime.go
@@ -12,7 +12,7 @@ package PACKAGE
 
 // emitted by compiler, not referred to by go programs
 
-func new(typ *byte) *any
+func newobject(typ *byte) *any
 func panicindex()
 func panicslice()
 func panicdivide()
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index eb9ce11316..e8d9e1ebcc 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -1915,7 +1915,7 @@ callnew(Type *t)
 	Node *fn;
 
 	dowidth(t);
-	fn = syslook("new", 1);
+	fn = syslook("newobject", 1);
 	argtype(fn, t);
 	return mkcall1(fn, ptrto(t), nil, typename(t));
 }