xref: /freebsd/usr.bin/dtc/util.hh (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 	 */
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>
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  */
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  */
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  */
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