xref: /freebsd/usr.bin/dtc/util.hh (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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 
33 #ifndef _UTIL_HH_
34 #define _UTIL_HH_
35 
36 #include <memory>
37 #include <stdint.h>
38 #include <string>
39 #include <vector>
40 
41 // If we aren't using C++11, then just ignore static asserts.
42 #if __cplusplus < 201103L
43 #ifndef static_assert
44 #define static_assert(x, y) ((void)0)
45 #endif
46 #endif
47 
48 #ifdef MISSING_DIGITTOINT
49 namespace
50 {
51 	/**
52 	 * Glibc doesn't have a definition of digittoint, so provide our own.
53 	 */
54 	inline int digittoint(int c)
55 	{
56 		switch (c)
57 		{
58 			default:
59 			case '0': return 0;
60 			case '1': return 1;
61 			case '2': return 2;
62 			case '3': return 3;
63 			case '4': return 4;
64 			case '5': return 5;
65 			case '6': return 6;
66 			case '7': return 7;
67 			case '8': return 8;
68 			case '9': return 9;
69 			case 'a': return 10;
70 			case 'b': return 11;
71 			case 'c': return 12;
72 			case 'd': return 13;
73 			case 'e': return 14;
74 			case 'f': return 15;
75 		}
76 	}
77 }
78 #endif
79 
80 namespace dtc {
81 
82 /**
83  * Type for a buffer of bytes.  This is used for a lot of short-lived temporary
84  * variables, so may eventually be changed to something like LLVM's
85  * SmallVector, but currently the program runs in a tiny fraction of a second,
86  * so this is not an issue.
87  */
88 typedef std::vector<uint8_t> byte_buffer;
89 
90 /**
91  * Helper function to push a big endian value into a byte buffer.  We use
92  * native-endian values for all of the in-memory data structures and only
93  * transform them into big endian form for output.
94  */
95 template<typename T>
96 inline void push_big_endian(byte_buffer &v, T val)
97 {
98 	static_assert(sizeof(T) > 1,
99 		"Big endian doesn't make sense for single-byte values");
100 	for (int bit=(sizeof(T) - 1)*8 ; bit>=0 ; bit-= 8)
101 	{
102 		v.push_back((val >> bit) & 0xff);
103 	}
104 }
105 
106 void push_string(byte_buffer &v, const std::string &s, bool escapes=false);
107 
108 /**
109  * Simple inline non-locale-aware check that this is a valid ASCII
110  * digit.
111  */
112 inline bool isdigit(char c)
113 {
114 	return (c >= '0') && (c <= '9');
115 }
116 
117 /**
118  * Simple inline non-locale-aware check that this is a valid ASCII
119  * hex digit.
120  */
121 inline bool ishexdigit(char c)
122 {
123 	return ((c >= '0') && (c <= '9')) || ((c >= 'a') && (c <= 'f')) ||
124 		((c >= 'A') && (c <= 'F'));
125 }
126 
127 /**
128  * Simple inline non-locale-aware check that this is a valid ASCII
129  * letter.
130  */
131 inline bool isalpha(char c)
132 {
133 	return ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'));
134 }
135 
136 /**
137  * A wrapper around dirname(3) that handles inconsistencies relating to memory
138  * management between platforms and provides a std::string interface.
139  */
140 std::string dirname(const std::string&);
141 
142 /**
143  * A wrapper around basename(3) that handles inconsistencies relating to memory
144  * management between platforms and provides a std::string interface.
145  */
146 std::string basename(const std::string&);
147 
148 }// namespace dtc
149 
150 #endif // !_UTIL_HH_
151