1 /* Optimized case-insensitive string comparison in C locale.
2 Copyright (C) 2001-2002, 2007, 2009-2023 Free Software Foundation, Inc.
3
4 This file is free software: you can redistribute it and/or modify
5 it under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 This file is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 /* Written by Bruno Haible <bruno@clisp.org>. */
18
19 #include "c-strcase.h"
20 #include "c-ctype.h"
21
22 /* STRCASEEQ allows to optimize string comparison with a small literal string.
23 STRCASEEQ (s, "UTF-8", 'U','T','F','-','8',0,0,0,0)
24 is semantically equivalent to
25 c_strcasecmp (s, "UTF-8") == 0
26 just faster. */
27
28 /* Help GCC to generate good code for string comparisons with
29 immediate strings. */
30 #if (defined __GNUC__ || defined __clang__) && defined __OPTIMIZE__
31
32 /* Case insensitive comparison of ASCII characters. */
33 # if C_CTYPE_ASCII
34 # define CASEEQ(other,upper) \
35 (c_isupper (upper) ? ((other) & ~0x20) == (upper) : (other) == (upper))
36 # else
37 # define CASEEQ(other,upper) \
38 (c_toupper (other) == (upper))
39 # endif
40
41 static inline int
42 strcaseeq9 (const char *s1, const char *s2)
43 {
44 return c_strcasecmp (s1 + 9, s2 + 9) == 0;
45 }
46
47 static inline int
48 strcaseeq8 (const char *s1, const char *s2, char s28)
49 {
50 if (CASEEQ (s1[8], s28))
51 {
52 if (s28 == 0)
53 return 1;
54 else
55 return strcaseeq9 (s1, s2);
56 }
57 else
58 return 0;
59 }
60
61 static inline int
62 strcaseeq7 (const char *s1, const char *s2, char s27, char s28)
63 {
64 if (CASEEQ (s1[7], s27))
65 {
66 if (s27 == 0)
67 return 1;
68 else
69 return strcaseeq8 (s1, s2, s28);
70 }
71 else
72 return 0;
73 }
74
75 static inline int
76 strcaseeq6 (const char *s1, const char *s2, char s26, char s27, char s28)
77 {
78 if (CASEEQ (s1[6], s26))
79 {
80 if (s26 == 0)
81 return 1;
82 else
83 return strcaseeq7 (s1, s2, s27, s28);
84 }
85 else
86 return 0;
87 }
88
89 static inline int
90 strcaseeq5 (const char *s1, const char *s2, char s25, char s26, char s27, char s28)
91 {
92 if (CASEEQ (s1[5], s25))
93 {
94 if (s25 == 0)
95 return 1;
96 else
97 return strcaseeq6 (s1, s2, s26, s27, s28);
98 }
99 else
100 return 0;
101 }
102
103 static inline int
104 strcaseeq4 (const char *s1, const char *s2, char s24, char s25, char s26, char s27, char s28)
105 {
106 if (CASEEQ (s1[4], s24))
107 {
108 if (s24 == 0)
109 return 1;
110 else
111 return strcaseeq5 (s1, s2, s25, s26, s27, s28);
112 }
113 else
114 return 0;
115 }
116
117 static inline int
118 strcaseeq3 (const char *s1, const char *s2, char s23, char s24, char s25, char s26, char s27, char s28)
119 {
120 if (CASEEQ (s1[3], s23))
121 {
122 if (s23 == 0)
123 return 1;
124 else
125 return strcaseeq4 (s1, s2, s24, s25, s26, s27, s28);
126 }
127 else
128 return 0;
129 }
130
131 static inline int
132 strcaseeq2 (const char *s1, const char *s2, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
133 {
134 if (CASEEQ (s1[2], s22))
135 {
136 if (s22 == 0)
137 return 1;
138 else
139 return strcaseeq3 (s1, s2, s23, s24, s25, s26, s27, s28);
140 }
141 else
142 return 0;
143 }
144
145 static inline int
146 strcaseeq1 (const char *s1, const char *s2, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
147 {
148 if (CASEEQ (s1[1], s21))
149 {
150 if (s21 == 0)
151 return 1;
152 else
153 return strcaseeq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28);
154 }
155 else
156 return 0;
157 }
158
159 static inline int
160 strcaseeq0 (const char *s1, const char *s2, char s20, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
161 {
162 if (CASEEQ (s1[0], s20))
163 {
164 if (s20 == 0)
165 return 1;
166 else
167 return strcaseeq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28);
168 }
169 else
170 return 0;
171 }
172
173 #define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
174 strcaseeq0 (s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28)
175
176 #else
177
178 #define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
179 (c_strcasecmp (s1, s2) == 0)
180
181 #endif