1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
//
// utils.c - Some helper code for debugging and error logging.
//
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include "utils.h"
//
// Helper function to skip past all spaces (and comments)
// Returns a pointer to the first non-space character.
//
const char *after_spaces(const char *str)
{
int block_comment_depth = 0;
// Skip whitespace and comments:
skip_whitespace:
switch (*str) {
case ' ': case '\r': case '\n': case '\t': {
++str;
goto skip_whitespace;
}
case '#': {
if (str[1] == '(') {
++block_comment_depth;
for (str += 2; *str && block_comment_depth > 0; ++str) {
if (str[0] == '#' && str[1] == '(') {
++block_comment_depth;
++str;
} else if (str[0] == ')' && str[1] == '#') {
--block_comment_depth;
++str;
}
}
} else {
while (*str && *str != '\n') ++str;
}
goto skip_whitespace;
}
}
return str;
}
//
// Return the first character after a valid BP name, or NULL if none is
// found.
//
const char *after_name(const char *str)
{
if (*str == '|') return &str[1];
if (*str == '^' || *str == '_' || *str == '$') {
return (str[1] == *str) ? &str[2] : &str[1];
}
if (!isalpha(*str)) return NULL;
for (++str; *str; ++str) {
if (!(isalnum(*str) || *str == '-'))
break;
}
return str;
}
//
// Check if a character is found and if so, move past it.
//
int matchchar(const char **str, char c)
{
const char *next = after_spaces(*str);
if (*next == c) {
*str = &next[1];
return 1;
} else {
return 0;
}
}
//
// Check if a string is found and if so, move past it.
//
int matchstr(const char **str, const char *target)
{
const char *next = after_spaces(*str);
if (strncmp(next, target, strlen(target)) == 0) {
*str = &next[strlen(target)];
return 1;
} else {
return 0;
}
}
//
// Process a string escape sequence for a character and return the
// character that was escaped.
// Set *end = the first character past the end of the escape sequence.
//
unsigned char unescapechar(const char *escaped, const char **end)
{
size_t len = 1;
unsigned char ret = (unsigned char)*escaped;
switch (*escaped) {
case 'a': ret = '\a'; break; case 'b': ret = '\b'; break;
case 'n': ret = '\n'; break; case 'r': ret = '\r'; break;
case 't': ret = '\t'; break; case 'v': ret = '\v'; break;
case 'e': ret = '\033'; break;
case 'x': { // Hex
static const unsigned char hextable[255] = {
['0']=0x10, ['1']=0x1, ['2']=0x2, ['3']=0x3, ['4']=0x4,
['5']=0x5, ['6']=0x6, ['7']=0x7, ['8']=0x8, ['9']=0x9,
['a']=0xa, ['b']=0xb, ['c']=0xc, ['d']=0xd, ['e']=0xe, ['f']=0xf,
['A']=0xa, ['B']=0xb, ['C']=0xc, ['D']=0xd, ['E']=0xe, ['F']=0xf,
};
if (hextable[(int)escaped[1]] && hextable[(int)escaped[2]]) {
ret = (hextable[(int)escaped[1]] << 4) | (hextable[(int)escaped[2]] & 0xF);
len = 3;
}
break;
}
case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': { // Octal
ret = (unsigned char)escaped[0] - '0';
if ('0' <= escaped[1] && escaped[1] <= '7') {
++len;
ret = (ret << 3) | (escaped[1] - '0');
if ('0' <= escaped[2] && escaped[2] <= '7') {
++len;
ret = (ret << 3) | (escaped[2] - '0');
}
}
break;
}
default: break;
}
*end = &escaped[len];
return ret;
}
//
// Write an unescaped version of `src` to `dest` (at most bufsize-1 chars,
// terminated by a null byte)
//
size_t unescape_string(char *dest, const char *src, size_t bufsize)
{
size_t len = 0;
#define PUT(c) do { *(dest++) = (char)(c); ++len; } while (0)
for ( ; *src && len < bufsize; ++src) {
if (*src != '\\') {
PUT(*src);
continue;
}
++src;
switch (*src) {
case 'a': PUT('\a'); break; case 'b': PUT('\b'); break;
case 'n': PUT('\n'); break; case 'r': PUT('\r'); break;
case 't': PUT('\t'); break; case 'v': PUT('\v'); break;
case 'e': PUT('\033'); break;
case 'x': { // Hex
static const char hextable[255] = {
['0']=0x10, ['1']=0x1, ['2']=0x2, ['3']=0x3, ['4']=0x4,
['5']=0x5, ['6']=0x6, ['7']=0x7, ['8']=0x8, ['9']=0x9,
['a']=0xa, ['b']=0xb, ['c']=0xc, ['d']=0xd, ['e']=0xe, ['f']=0xf,
['A']=0xa, ['B']=0xb, ['C']=0xc, ['D']=0xd, ['E']=0xe, ['F']=0xf,
};
if (hextable[(int)src[1]] && hextable[(int)src[2]]) {
PUT((hextable[(int)src[1]] << 4) | (hextable[(int)src[2]] & 0xF));
src += 2;
}
break;
}
case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': { // Octal
int c = *src - '0';
if ('0' <= src[1] && src[1] <= '7') {
++src;
c = (c << 3) | (*src - '0');
if ('0' <= src[1] && src[1] <= '7' && (c << 3) < 256) {
++src;
c = (c << 3) | (*src - '0');
}
}
PUT(c);
break;
}
default: PUT(*src); break;
}
}
*dest = '\0';
return len;
#undef PUT
}
//
// Fail and exit if a memory value is NULL
//
void *memcheck(void *p)
{
if (p == NULL) {
fprintf(stderr, "memory allocation failure\n");
_exit(1);
}
return p;
}
//
// Case-insensitive memory comparison
//
int memicmp(const void *v1, const void *v2, size_t n)
{
int result = 0;
const char *s1 = (const char*)v1, *s2 = (const char*)v2;
while (n-- > 0 && (result = tolower(*(s1++)) - tolower(*(s2++))) == 0)
;
return result;
}
//
// Free memory, but also set the pointer to NULL for safety
//
void xfree(void *p)
{
if (*(void**)p == NULL) {
fprintf(stderr, "Attempt to free(NULL)\n");
_exit(1);
}
free(*(void**)p);
p = NULL;
}
// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1
|
