1 /*
2  * Copyright © 2012 Ran Benita <ran234@gmail.com>
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21  * DEALINGS IN THE SOFTWARE.
22  */
23 
24 #ifndef XKBCOMP_SCANNER_UTILS_H
25 #define XKBCOMP_SCANNER_UTILS_H
26 
27 /* Point to some substring in the file; used to avoid copying. */
28 struct sval {
29     const char *start;
30     unsigned int len;
31 };
32 typedef darray(struct sval) darray_sval;
33 
34 static inline bool
svaleq(struct sval s1,struct sval s2)35 svaleq(struct sval s1, struct sval s2)
36 {
37     return s1.len == s2.len && memcmp(s1.start, s2.start, s1.len) == 0;
38 }
39 
40 static inline bool
svaleq_prefix(struct sval s1,struct sval s2)41 svaleq_prefix(struct sval s1, struct sval s2)
42 {
43     return s1.len <= s2.len && memcmp(s1.start, s2.start, s1.len) == 0;
44 }
45 
46 struct scanner {
47     const char *s;
48     size_t pos;
49     size_t len;
50     char buf[1024];
51     size_t buf_pos;
52     size_t line, column;
53     /* The line/column of the start of the current token. */
54     size_t token_line, token_column;
55     const char *file_name;
56     struct xkb_context *ctx;
57     void *priv;
58 };
59 
60 #define scanner_log(scanner, level, fmt, ...) \
61     xkb_log((scanner)->ctx, (level), 0, \
62             "%s:%zu:%zu: " fmt "\n", \
63              (scanner)->file_name, \
64              (scanner)->token_line, (scanner)->token_column, ##__VA_ARGS__)
65 
66 #define scanner_err(scanner, fmt, ...) \
67     scanner_log(scanner, XKB_LOG_LEVEL_ERROR, fmt, ##__VA_ARGS__)
68 
69 #define scanner_warn(scanner, fmt, ...) \
70     scanner_log(scanner, XKB_LOG_LEVEL_WARNING, fmt, ##__VA_ARGS__)
71 
72 static inline void
scanner_init(struct scanner * s,struct xkb_context * ctx,const char * string,size_t len,const char * file_name,void * priv)73 scanner_init(struct scanner *s, struct xkb_context *ctx,
74              const char *string, size_t len, const char *file_name,
75              void *priv)
76 {
77     s->s = string;
78     s->len = len;
79     s->pos = 0;
80     s->line = s->column = 1;
81     s->token_line = s->token_column = 1;
82     s->file_name = file_name;
83     s->ctx = ctx;
84     s->priv = priv;
85 }
86 
87 static inline char
peek(struct scanner * s)88 peek(struct scanner *s)
89 {
90     if (unlikely(s->pos >= s->len))
91         return '\0';
92     return s->s[s->pos];
93 }
94 
95 static inline bool
eof(struct scanner * s)96 eof(struct scanner *s)
97 {
98     return s->pos >= s->len;
99 }
100 
101 static inline bool
eol(struct scanner * s)102 eol(struct scanner *s)
103 {
104     return peek(s) == '\n';
105 }
106 
107 static inline void
skip_to_eol(struct scanner * s)108 skip_to_eol(struct scanner *s)
109 {
110     const char *nl = memchr(s->s + s->pos, '\n', s->len - s->pos);
111     const size_t new_pos = nl ? (size_t) (nl - s->s) : s->len;
112     s->column += new_pos - s->pos;
113     s->pos = new_pos;
114 }
115 
116 static inline char
next(struct scanner * s)117 next(struct scanner *s)
118 {
119     if (unlikely(eof(s)))
120         return '\0';
121     if (unlikely(eol(s))) {
122         s->line++;
123         s->column = 1;
124     }
125     else {
126         s->column++;
127     }
128     return s->s[s->pos++];
129 }
130 
131 static inline bool
chr(struct scanner * s,char ch)132 chr(struct scanner *s, char ch)
133 {
134     if (likely(peek(s) != ch))
135         return false;
136     s->pos++; s->column++;
137     return true;
138 }
139 
140 static inline bool
str(struct scanner * s,const char * string,size_t len)141 str(struct scanner *s, const char *string, size_t len)
142 {
143     if (s->len - s->pos < len)
144         return false;
145     if (memcmp(s->s + s->pos, string, len) != 0)
146         return false;
147     s->pos += len; s->column += len;
148     return true;
149 }
150 
151 #define lit(s, literal) str(s, literal, sizeof(literal) - 1)
152 
153 static inline bool
buf_append(struct scanner * s,char ch)154 buf_append(struct scanner *s, char ch)
155 {
156     if (s->buf_pos + 1 >= sizeof(s->buf))
157         return false;
158     s->buf[s->buf_pos++] = ch;
159     return true;
160 }
161 
162 static inline bool
buf_appends(struct scanner * s,const char * str)163 buf_appends(struct scanner *s, const char *str)
164 {
165     int ret;
166     ret = snprintf(s->buf + s->buf_pos, sizeof(s->buf) - s->buf_pos, "%s", str);
167     if (ret < 0 || (size_t) ret >= sizeof(s->buf) - s->buf_pos)
168         return false;
169     s->buf_pos += ret;
170     return true;
171 }
172 
173 static inline bool
oct(struct scanner * s,uint8_t * out)174 oct(struct scanner *s, uint8_t *out)
175 {
176     int i;
177     for (i = 0, *out = 0; peek(s) >= '0' && peek(s) <= '7' && i < 3; i++)
178         *out = *out * 8 + next(s) - '0';
179     return i > 0;
180 }
181 
182 static inline bool
hex(struct scanner * s,uint8_t * out)183 hex(struct scanner *s, uint8_t *out)
184 {
185     int i;
186     for (i = 0, *out = 0; is_xdigit(peek(s)) && i < 2; i++) {
187         const char c = next(s);
188         const char offset = (c >= '0' && c <= '9' ? '0' :
189                              c >= 'a' && c <= 'f' ? 'a' - 10 : 'A' - 10);
190         *out = *out * 16 + c - offset;
191     }
192     return i > 0;
193 }
194 
195 #endif
196