1 files changed, 175 insertions, 0 deletions
diff --git a/src/pkg/runtime/slice.c b/src/pkg/runtime/slice.c
new file mode 100644
index 000000000..d7a5a062f
--- /dev/null
+++ b/src/pkg/runtime/slice.c
@@ -0,0 +1,175 @@
+// Copyright 2009 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.
+
+#include "runtime.h"
+
+static	int32	debug	= 0;
+
+// makeslice(nel int, cap int, width int) (ary []any);
+void
+sys·makeslice(uint32 nel, uint32 cap, uint32 width, Slice ret)
+{
+	uint64 size;
+
+	if(cap < nel)
+		cap = nel;
+	size = cap*width;
+
+	ret.len = nel;
+	ret.cap = cap;
+	ret.array = mal(size);
+
+	FLUSH(&ret);
+
+	if(debug) {
+		prints("makeslice: nel=");
+		sys·printint(nel);
+		prints("; cap=");
+		sys·printint(cap);
+		prints("; width=");
+		sys·printint(width);
+		prints("; ret=");
+		sys·printslice(ret);
+		prints("\n");
+	}
+}
+
+static void
+throwslice(uint32 lb, uint32 hb, uint32 n)
+{
+	prints("slice[");
+	sys·printint(lb);
+	prints(":");
+	sys·printint(hb);
+	prints("] of [");
+	sys·printint(n);
+	prints("] array\n");
+	throw("array slice");
+}
+
+// sliceslice(old []any, lb int, hb int, width int) (ary []any);
+void
+sys·sliceslice(Slice old, uint32 lb, uint32 hb, uint32 width, Slice ret)
+{
+
+	if(hb > old.cap || lb > hb) {
+		if(debug) {
+			prints("sys·sliceslice: old=");
+			sys·printslice(old);
+			prints("; lb=");
+			sys·printint(lb);
+			prints("; hb=");
+			sys·printint(hb);
+			prints("; width=");
+			sys·printint(width);
+			prints("\n");
+
+			prints("oldarray: nel=");
+			sys·printint(old.len);
+			prints("; cap=");
+			sys·printint(old.cap);
+			prints("\n");
+		}
+		throwslice(lb, hb, old.cap);
+	}
+
+	// new array is inside old array
+	ret.len = hb-lb;
+	ret.cap = old.cap - lb;
+	ret.array = old.array + lb*width;
+
+	FLUSH(&ret);
+
+	if(debug) {
+		prints("sys·sliceslice: old=");
+		sys·printslice(old);
+		prints("; lb=");
+		sys·printint(lb);
+		prints("; hb=");
+		sys·printint(hb);
+		prints("; width=");
+		sys·printint(width);
+		prints("; ret=");
+		sys·printslice(ret);
+		prints("\n");
+	}
+}
+
+// slicearray(old *any, nel int, lb int, hb int, width int) (ary []any);
+void
+sys·slicearray(byte* old, uint32 nel, uint32 lb, uint32 hb, uint32 width, Slice ret)
+{
+
+	if(hb > nel || lb > hb) {
+		if(debug) {
+			prints("sys·slicearray: old=");
+			sys·printpointer(old);
+			prints("; nel=");
+			sys·printint(nel);
+			prints("; lb=");
+			sys·printint(lb);
+			prints("; hb=");
+			sys·printint(hb);
+			prints("; width=");
+			sys·printint(width);
+			prints("\n");
+		}
+		throwslice(lb, hb, nel);
+	}
+
+	// new array is inside old array
+	ret.len = hb-lb;
+	ret.cap = nel-lb;
+	ret.array = old + lb*width;
+
+	FLUSH(&ret);
+
+	if(debug) {
+		prints("sys·slicearray: old=");
+		sys·printpointer(old);
+		prints("; nel=");
+		sys·printint(nel);
+		prints("; lb=");
+		sys·printint(lb);
+		prints("; hb=");
+		sys·printint(hb);
+		prints("; width=");
+		sys·printint(width);
+		prints("; ret=");
+		sys·printslice(ret);
+		prints("\n");
+	}
+}
+
+// arraytoslice(old *any, nel int) (ary []any)
+void
+sys·arraytoslice(byte* old, uint32 nel, Slice ret)
+{
+
+	// new dope to old array
+	ret.len = nel;
+	ret.cap = nel;
+	ret.array = old;
+
+	FLUSH(&ret);
+
+	if(debug) {
+		prints("sys·slicearrayp: old=");
+		sys·printpointer(old);
+		prints("; ret=");
+		sys·printslice(ret);
+		prints("\n");
+	}
+}
+
+void
+sys·printslice(Slice a)
+{
+	prints("[");
+	sys·printint(a.len);
+	prints("/");
+	sys·printint(a.cap);
+	prints("]");
+	sys·printpointer(a.array);
+}