rt.compiler.dmd.rt.arraycat source code

1 /**
2  * Part of the D programming language runtime library.
3  */
4 
5 /*
6  *  Copyright (C) 2004-2007 by Digital Mars, www.digitalmars.com
7  *  Written by Walter Bright
8  *
9  *  This software is provided 'as-is', without any express or implied
10  *  warranty. In no event will the authors be held liable for any damages
11  *  arising from the use of this software.
12  *
13  *  Permission is granted to anyone to use this software for any purpose,
14  *  including commercial applications, and to alter it and redistribute it
15  *  freely, in both source and binary form, subject to the following
16  *  restrictions:
17  *
18  *  o  The origin of this software must not be misrepresented; you must not
19  *     claim that you wrote the original software. If you use this software
20  *     in a product, an acknowledgment in the product documentation would be
21  *     appreciated but is not required.
22  *  o  Altered source versions must be plainly marked as such, and must not
23  *     be misrepresented as being the original software.
24  *  o  This notice may not be removed or altered from any source
25  *     distribution.
26  */
27 
28 /*
29  *  Modified by Sean Kelly <sean@f4.ca> for use with Tango.
30  */
31 
32 module rt.compiler.dmd.rt.arraycat;
33 
34 private
35 {
36     import tango.stdc.string : memcpy;
37     debug(ARRAY_COPY) import tango.stdc.stdio : printf;
38 }
39 
40 extern (C):
41 
42 byte[] _d_arraycopy(size_t size, byte[] from, byte[] to)
43 {
44     debug(ARRAY_COPY) printf("f = %p,%d, t = %p,%d, size = %d\n",
45                  from.ptr, from.length, to.ptr, to.length, size);
46 
47     if (to.length != from.length)
48     {
49         throw new Exception("lengths don't match for array copy");
50     }
51     else if (to.ptr + to.length * size <= from.ptr ||
52              from.ptr + from.length * size <= to.ptr)
53     {
54         memcpy(to.ptr, from.ptr, to.length * size);
55     }
56     else
57     {
58         throw new Exception("overlapping array copy");
59     }
60     return to;
61 }