xref: /freebsd/usr.bin/dtc/util.hh (revision e14ddd1f16e7e5788392c50de21ea7c927e0690c)
1 /*-
2  * Copyright (c) 2013 David Chisnall
3  * All rights reserved.
4  *
5  * This software was developed by SRI International and the University of
6  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
7  * ("CTSRD"), as part of the DARPA CRASH research programme.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef _UTIL_HH_
34 #define _UTIL_HH_
35 
36 #include <vector>
37 
38 // If we aren't using C++11, then just ignore static asserts.
39 #if __cplusplus < 201103L
40 #ifndef static_assert
41 #define static_assert(x, y) ((void)0)
42 #endif
43 #endif
44 
45 namespace dtc {
46 
47 /**
48  * Type for a buffer of bytes.  This is used for a lot of short-lived temporary
49  * variables, so may eventually be changed to something like LLVM's
50  * SmallVector, but currently the program runs in a tiny fraction of a second,
51  * so this is not an issue.
52  */
53 typedef std::vector<uint8_t> byte_buffer;
54 
55 /**
56  * Helper function to push a big endian value into a byte buffer.  We use
57  * native-endian values for all of the in-memory data structures and only
58  * transform them into big endian form for output.
59  */
60 template<typename T>
61 inline void push_big_endian(byte_buffer &v, T val)
62 {
63 	static_assert(sizeof(T) > 1,
64 		"Big endian doesn't make sense for single-byte values");
65 	for (int bit=(sizeof(T) - 1)*8 ; bit>=0 ; bit-= 8)
66 	{
67 		v.push_back((val >> bit) & 0xff);
68 	}
69 }
70 
71 /**
72  * Simple inline non-locale-aware check that this is a valid ASCII
73  * digit.
74  */
75 inline bool isdigit(char c)
76 {
77 	return (c >= '0') && (c <= '9');
78 }
79 
80 /**
81  * Simple inline non-locale-aware check that this is a valid ASCII
82  * hex digit.
83  */
84 inline bool ishexdigit(char c)
85 {
86 	return ((c >= '0') && (c <= '9')) || ((c >= 'a') && (c <= 'f')) ||
87 		((c >= 'A') && (c <= 'Z'));
88 }
89 
90 }// namespace dtc
91 
92 #endif // !_UTIL_HH_
93