Started the safer malloc() system.

draw.go

@@ -4,12 +4,13 @@ package ui
 
 // #include <stdlib.h>
 // #include "ui.h"
+// // TODO figure this one out
+// extern void *uimalloc(size_t);
 // static uiDrawBrush *newBrush(void)
 // {
 // 	uiDrawBrush *b;
 // 
-// 	b = (uiDrawBrush *) malloc(sizeof (uiDrawBrush));
+// 	b = (uiDrawBrush *) uimalloc(sizeof (uiDrawBrush));
-// 	// TODO
 // 	return b;
 // }
 // static uiDrawBrushGradientStop *newStops(size_t n)

util.go

@@ -7,8 +7,22 @@ import (
 )
 
 // #include <stdlib.h>
+// // TODO remove when switching to Go 1.7
+// #include <string.h>
 import "C"
 
+// TODO move this to C.CBytes() when switching to Go 1.7
+
+//export uimalloc
+func uimalloc(n C.size_t) unsafe.Pointer {
+	p := C.malloc(n)
+	if p == nil {
+		panic("out of memory in uimalloc()")
+	}
+	C.memset(p, 0, n)
+	return p
+}
+
 func freestr(str *C.char) {
 	C.free(unsafe.Pointer(str))
 }