1 #include "less.h"
2 #include "xbuf.h"
3
4 /*
5 * Initialize an expandable text buffer.
6 */
xbuf_init(struct xbuffer * xbuf)7 public void xbuf_init(struct xbuffer *xbuf)
8 {
9 xbuf->data = NULL;
10 xbuf->size = xbuf->end = 0;
11 }
12
xbuf_deinit(struct xbuffer * xbuf)13 public void xbuf_deinit(struct xbuffer *xbuf)
14 {
15 if (xbuf->data != NULL)
16 free(xbuf->data);
17 xbuf_init(xbuf);
18 }
19
xbuf_reset(struct xbuffer * xbuf)20 public void xbuf_reset(struct xbuffer *xbuf)
21 {
22 xbuf->end = 0;
23 }
24
25 /*
26 * Add a byte to an expandable text buffer.
27 */
xbuf_add_byte(struct xbuffer * xbuf,unsigned char b)28 public void xbuf_add_byte(struct xbuffer *xbuf, unsigned char b)
29 {
30 if (xbuf->end >= xbuf->size)
31 {
32 unsigned char *data;
33 if (ckd_add(&xbuf->size, xbuf->size, xbuf->size ? xbuf->size : 16))
34 out_of_memory();
35 data = (unsigned char *) ecalloc(xbuf->size, sizeof(unsigned char));
36 if (xbuf->data != NULL)
37 {
38 memcpy(data, xbuf->data, xbuf->end);
39 free(xbuf->data);
40 }
41 xbuf->data = data;
42 }
43 xbuf->data[xbuf->end++] = (unsigned char) b;
44 }
45
xbuf_add_data(struct xbuffer * xbuf,unsigned char * data,int len)46 public void xbuf_add_data(struct xbuffer *xbuf, unsigned char *data, int len)
47 {
48 int i;
49 for (i = 0; i < len; i++)
50 xbuf_add_byte(xbuf, data[i]);
51 }
52
xbuf_pop(struct xbuffer * buf)53 public int xbuf_pop(struct xbuffer *buf)
54 {
55 if (buf->end == 0)
56 return -1;
57 return (int) buf->data[--(buf->end)];
58 }
59
xbuf_set(struct xbuffer * dst,struct xbuffer * src)60 public void xbuf_set(struct xbuffer *dst, struct xbuffer *src)
61 {
62 xbuf_reset(dst);
63 xbuf_add_data(dst, src->data, src->end);
64 }
65
xbuf_char_data(struct xbuffer * xbuf)66 public char * xbuf_char_data(struct xbuffer *xbuf)
67 {
68 return (char *)(xbuf->data);
69 }
70
71
72 /*
73 * Helper functions for the ckd_add and ckd_mul macro substitutes.
74 * These helper functions do not set *R on overflow, and assume that
75 * arguments are nonnegative, that INTMAX_MAX <= UINTMAX_MAX, and that
76 * sizeof is a reliable way to distinguish integer representations.
77 * Despite these limitations they are good enough for 'less' on all
78 * known practical platforms. For more-complicated substitutes
79 * without most of these limitations, see Gnulib's stdckdint module.
80 */
81 #if !HAVE_STDCKDINT_H
82 /*
83 * If the integer *R can represent VAL, store the value and return FALSE.
84 * Otherwise, possibly set *R to an indeterminate value and return TRUE.
85 * R has size RSIZE, and is signed if and only if RSIGNED is nonzero.
86 */
help_fixup(void * r,uintmax val,int rsize,int rsigned)87 static int help_fixup(void *r, uintmax val, int rsize, int rsigned)
88 {
89 if (rsigned)
90 {
91 if (rsize == sizeof (int))
92 {
93 int *pr = r;
94 if (INT_MAX < val)
95 return TRUE;
96 *pr = (int) val;
97 #ifdef LLONG_MAX
98 } else if (rsize == sizeof (long long))
99 {
100 long long *pr = r;
101 if (LLONG_MAX < val)
102 return TRUE;
103 *pr = val;
104 #endif
105 #ifdef INTMAX_MAX
106 } else if (rsize == sizeof (intmax_t)) {
107 intmax_t *pr = r;
108 if (INTMAX_MAX < val)
109 return TRUE;
110 *pr = val;
111 #endif
112 } else /* rsize == sizeof (long) */
113 {
114 long *pr = r;
115 if (LONG_MAX < val)
116 return TRUE;
117 *pr = (long) val;
118 }
119 } else {
120 if (rsize == sizeof (unsigned)) {
121 unsigned *pr = r;
122 if (UINT_MAX < val)
123 return TRUE;
124 *pr = (unsigned) val;
125 } else if (rsize == sizeof (unsigned long)) {
126 unsigned long *pr = r;
127 if (ULONG_MAX < val)
128 return TRUE;
129 *pr = (unsigned long) val;
130 #ifdef ULLONG_MAX
131 } else if (rsize == sizeof (unsigned long long)) {
132 long long *pr = r;
133 if (ULLONG_MAX < val)
134 return TRUE;
135 *pr = val;
136 #endif
137 } else /* rsize == sizeof (uintmax) */
138 {
139 uintmax *pr = r;
140 *pr = val;
141 }
142 }
143 return FALSE;
144 }
145 /*
146 * If *R can represent the mathematical sum of A and B, store the sum
147 * and return FALSE. Otherwise, possibly set *R to an indeterminate
148 * value and return TRUE. R has size RSIZE, and is signed if and only
149 * if RSIGNED is nonzero.
150 */
help_ckd_add(void * r,uintmax a,uintmax b,int rsize,int rsigned)151 public int help_ckd_add(void *r, uintmax a, uintmax b, int rsize, int rsigned)
152 {
153 uintmax sum = a + b;
154 return sum < a || help_fixup(r, sum, rsize, rsigned);
155 }
156 /* Likewise, but for the product of A and B. */
help_ckd_mul(void * r,uintmax a,uintmax b,int rsize,int rsigned)157 public int help_ckd_mul(void *r, uintmax a, uintmax b, int rsize, int rsigned)
158 {
159 uintmax product = a * b;
160 return ((b != 0 && a != product / b)
161 || help_fixup(r, product, rsize, rsigned));
162 }
163 #endif
164