OpenMPI
0.1.1
Main Page
Related Pages
Modules
Data Structures
Files
File List
Globals
convert.h
Go to the documentation of this file.
1
/*
2
* Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
3
* University Research and Technology
4
* Corporation. All rights reserved.
5
* Copyright (c) 2004-2006 The University of Tennessee and The University
6
* of Tennessee Research Foundation. All rights
7
* reserved.
8
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
9
* University of Stuttgart. All rights reserved.
10
* Copyright (c) 2004-2005 The Regents of the University of California.
11
* All rights reserved.
12
* $COPYRIGHT$
13
*
14
* Additional copyrights may follow
15
*
16
* $HEADER$
17
*/
18
/**
19
* @file
20
*
21
* This file will hopefully not last long in the tree, but it's
22
* unfortunately necessary for now.
23
*
24
* There are multiple places in the code base where we need to safely
25
* convert from a size_t to an int. However, on some platforms,
26
* sizeof(size_t) is larger than sizeof(int), so casting from size_t
27
* -> int will result in a compiler warning and potentially data
28
* truncation.
29
*
30
* But, unfortunately, we still need to do it. But we definitely do
31
* not want compiler warnings. So when sizeof(size_t)>sizeof(int),
32
* the solution is the treat the size_t value like an array and
33
* dereference the appropriate nibble and cast that to an int (which
34
* accounts for both big and little endian machines).
35
*
36
* Most places in the code where this casting must occur are because
37
* collision of APIs (e.g., one API requires a size_t and another API
38
* requires an int. And in most places, we're not going to overflow
39
* the int when casting down into it (e.g., it's the result of a
40
* strlen, or the length of the buffer in an ompi_buffer_t -- if that
41
* buffer is larger than MAX_INT, we've got other problems!).
42
*
43
* BUT -- the whole premise of casting down to an int is dangerous.
44
* So we provide extra protection here to detect overflow situations
45
* and print out appropriate warnings. So if this situation ever
46
* occurs, we'll still overflow, but we'll have a good indication that
47
* it's happening, and where.
48
*/
49
50
#ifndef OPAL_CONVERT_H
51
#define OPAL_CONVERT_H
52
53
#include "opal_config.h"
54
55
BEGIN_C_DECLS
56
57
/**
58
* Convert a size_t to an int.
59
*
60
* @param in The size_t value to be converted
61
* @param out The output int value.
62
* @param want_check Whether to check for truncation or not
63
*
64
* @returns OPAL_SUCESS If all went well
65
* @returns OPAL_NOT_SUPPORTED if the size_t value was truncated
66
*
67
* The conversion will always occur. However, if the size_t value was
68
* truncated (i.e., sizeof(size_t) > sizeof(int), and the cast down to
69
* the int actually changed the value), OPAL_NOT_SUPPORTED will be
70
* returned.
71
*
72
* On platforms where sizeof(size_t) <= sizeof(int), this function
73
* will aways return OPAL_SUCCESS.
74
*/
75
OPAL_DECLSPEC
int
opal_size2int
(
size_t
in,
int
*out,
bool
want_check) __opal_attribute_nonnull__(2);
76
77
END_C_DECLS
78
79
#endif
opal_size2int
BEGIN_C_DECLS OPAL_DECLSPEC int opal_size2int(size_t in, int *out, bool want_check) __opal_attribute_nonnull__(2)
Convert a size_t to an int.
Definition:
convert.c:31
opal
util
convert.h
Generated on Wed Dec 24 2014 12:05:29 for OpenMPI by
1.8.8