1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2013 David Chisnall
5 * All rights reserved.
6 *
7 * This software was developed by SRI International and the University of
8 * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
9 * ("CTSRD"), as part of the DARPA CRASH research programme.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD$
33 */
34
35 #ifndef _UTIL_HH_
36 #define _UTIL_HH_
37
38 #include <memory>
39 #include <stdint.h>
40 #include <string>
41 #include <vector>
42
43 // If we aren't using C++11, then just ignore static asserts.
44 #if __cplusplus < 201103L
45 #ifndef static_assert
46 #define static_assert(x, y) ((void)0)
47 #endif
48 #endif
49
50 #ifdef MISSING_DIGITTOINT
51 namespace
52 {
53 /**
54 * Glibc doesn't have a definition of digittoint, so provide our own.
55 */
digittoint(int c)56 inline int digittoint(int c)
57 {
58 switch (c)
59 {
60 default:
61 case '0': return 0;
62 case '1': return 1;
63 case '2': return 2;
64 case '3': return 3;
65 case '4': return 4;
66 case '5': return 5;
67 case '6': return 6;
68 case '7': return 7;
69 case '8': return 8;
70 case '9': return 9;
71 case 'a': return 10;
72 case 'b': return 11;
73 case 'c': return 12;
74 case 'd': return 13;
75 case 'e': return 14;
76 case 'f': return 15;
77 }
78 }
79 }
80 #endif
81
82 namespace dtc {
83
84 /**
85 * Type for a buffer of bytes. This is used for a lot of short-lived temporary
86 * variables, so may eventually be changed to something like LLVM's
87 * SmallVector, but currently the program runs in a tiny fraction of a second,
88 * so this is not an issue.
89 */
90 typedef std::vector<uint8_t> byte_buffer;
91
92 /**
93 * Helper function to push a big endian value into a byte buffer. We use
94 * native-endian values for all of the in-memory data structures and only
95 * transform them into big endian form for output.
96 */
97 template<typename T>
push_big_endian(byte_buffer & v,T val)98 inline void push_big_endian(byte_buffer &v, T val)
99 {
100 static_assert(sizeof(T) > 1,
101 "Big endian doesn't make sense for single-byte values");
102 for (int bit=(sizeof(T) - 1)*8 ; bit>=0 ; bit-= 8)
103 {
104 v.push_back((val >> bit) & 0xff);
105 }
106 }
107
108 void push_string(byte_buffer &v, const std::string &s, bool escapes=false);
109
110 /**
111 * Simple inline non-locale-aware check that this is a valid ASCII
112 * digit.
113 */
isdigit(char c)114 inline bool isdigit(char c)
115 {
116 return (c >= '0') && (c <= '9');
117 }
118
119 /**
120 * Simple inline non-locale-aware check that this is a valid ASCII
121 * hex digit.
122 */
ishexdigit(char c)123 inline bool ishexdigit(char c)
124 {
125 return ((c >= '0') && (c <= '9')) || ((c >= 'a') && (c <= 'f')) ||
126 ((c >= 'A') && (c <= 'F'));
127 }
128
129 /**
130 * Simple inline non-locale-aware check that this is a valid ASCII
131 * letter.
132 */
isalpha(char c)133 inline bool isalpha(char c)
134 {
135 return ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'));
136 }
137
138 /**
139 * A wrapper around dirname(3) that handles inconsistencies relating to memory
140 * management between platforms and provides a std::string interface.
141 */
142 std::string dirname(const std::string&);
143
144 /**
145 * A wrapper around basename(3) that handles inconsistencies relating to memory
146 * management between platforms and provides a std::string interface.
147 */
148 std::string basename(const std::string&);
149
150 }// namespace dtc
151
152 #endif // !_UTIL_HH_
153