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1 | /* |
2 | * Copyright (c) 2019 David Lamparter, for NetDEF, Inc. | |
3 | * | |
4 | * Permission to use, copy, modify, and distribute this software for any | |
5 | * purpose with or without fee is hereby granted, provided that the above | |
6 | * copyright notice and this permission notice appear in all copies. | |
7 | * | |
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
15 | */ | |
16 | ||
17 | #ifndef _FRR_PRINTFRR_H | |
18 | #define _FRR_PRINTFRR_H | |
19 | ||
20 | #include <stddef.h> | |
21 | #include <stdarg.h> | |
bf4d3d80 | 22 | #include <stdint.h> |
5c25bd87 DL |
23 | |
24 | #include "compiler.h" | |
25 | #include "memory.h" | |
26 | ||
27 | struct fbuf { | |
28 | char *buf; | |
29 | char *pos; | |
30 | size_t len; | |
31 | }; | |
32 | ||
33 | #define at(a, b) \ | |
34 | __attribute__((format(printf, a, b))) | |
35 | #define atn(a, b) \ | |
36 | at(a, b) __attribute__((nonnull(1) _RET_NONNULL)) | |
37 | #define atm(a, b) \ | |
38 | atn(a, b) __attribute__((malloc)) | |
39 | ||
40 | /* return value is length needed for the full string (excluding \0) in all | |
41 | * cases. The functions write as much as they can, but continue regardless, | |
42 | * so the return value is independent of buffer length. Both bprintfrr and | |
43 | * snprintf also accept NULL as output buffer. | |
44 | */ | |
45 | ||
46 | /* bprintfrr does NOT null terminate! use sparingly (only provided since it's | |
47 | * the most direct interface) - useful for incrementally building long text | |
48 | * (call bprintfrr repeatedly with the same buffer) | |
49 | */ | |
50 | ssize_t vbprintfrr(struct fbuf *out, const char *fmt, va_list) at(2, 0); | |
51 | ssize_t bprintfrr(struct fbuf *out, const char *fmt, ...) at(2, 3); | |
52 | ||
53 | /* these do null terminate like their snprintf cousins */ | |
54 | ssize_t vsnprintfrr(char *out, size_t sz, const char *fmt, va_list) at(3, 0); | |
55 | ssize_t snprintfrr(char *out, size_t sz, const char *fmt, ...) at(3, 4); | |
56 | ||
57 | /* c = continue / concatenate (append at the end of the string) | |
58 | * return value is would-be string length (regardless of buffer length), | |
59 | * i.e. includes already written chars */ | |
60 | ssize_t vcsnprintfrr(char *out, size_t sz, const char *fmt, va_list) at(3, 0); | |
61 | ssize_t csnprintfrr(char *out, size_t sz, const char *fmt, ...) at(3, 4); | |
62 | ||
63 | /* memory allocations don't fail in FRR, so you always get something here. | |
64 | * (in case of error, returns a strdup of the format string) */ | |
65 | char *vasprintfrr(struct memtype *mt, const char *fmt, va_list) atm(2, 0); | |
66 | char *asprintfrr(struct memtype *mt, const char *fmt, ...) atm(2, 3); | |
67 | ||
68 | /* try to use provided buffer (presumably from stack), allocate if it's too | |
69 | * short. Must call XFREE(mt, return value) if return value != out. | |
70 | */ | |
71 | char *vasnprintfrr(struct memtype *mt, char *out, size_t sz, | |
72 | const char *fmt, va_list) atn(4, 0); | |
73 | char *asnprintfrr(struct memtype *mt, char *out, size_t sz, | |
74 | const char *fmt, ...) atn(4, 5); | |
75 | ||
76 | #undef at | |
77 | #undef atm | |
78 | ||
bf4d3d80 DL |
79 | /* extension specs must start with a capital letter (this is a restriction |
80 | * for both performance's and human understanding's sake.) | |
81 | * | |
82 | * Note that the entire thing mostly works because a letter directly following | |
83 | * a %p print specifier is extremely unlikely to occur (why would you want to | |
84 | * print "0x12345678HELLO"?) Normally, you'd expect spacing or punctuation | |
85 | * after a placeholder. That also means that neither of those works well for | |
86 | * extension purposes, e.g. "%p{foo}" is reasonable to see actually used. | |
87 | * | |
88 | * TODO: would be nice to support a "%pF%dF" specifier that consumes 2 | |
89 | * arguments, e.g. to pass an integer + a list of known values... can be | |
90 | * done, but a bit tricky. | |
91 | */ | |
92 | #define printfrr_ext_char(ch) ((ch) >= 'A' && (ch) <= 'Z') | |
5c25bd87 | 93 | |
bf4d3d80 DL |
94 | struct printfrr_ext { |
95 | /* embedded string to minimize cache line pollution */ | |
96 | char match[8]; | |
97 | ||
98 | /* both can be given, if not the code continues searching | |
99 | * (you can do %pX and %dX in 2 different entries) | |
100 | * | |
101 | * return value: number of bytes consumed from the format string, so | |
102 | * you can consume extra flags (e.g. register for "%pX", consume | |
103 | * "%pXfoo" or "%pXbar" for flags.) Convention is to make those flags | |
104 | * lowercase letters or numbers. | |
105 | * | |
106 | * bsz is a compile-time constant in printf; it's gonna be relatively | |
107 | * small. This isn't designed to print Shakespeare from a pointer. | |
108 | * | |
109 | * prec is the precision specifier (the 999 in "%.999p") -1 means | |
110 | * none given (value in the format string cannot be negative) | |
111 | */ | |
112 | ssize_t (*print_ptr)(char *buf, size_t bsz, const char *fmt, int prec, | |
113 | const void *); | |
114 | ssize_t (*print_int)(char *buf, size_t bsz, const char *fmt, int prec, | |
115 | uintmax_t); | |
5c25bd87 DL |
116 | }; |
117 | ||
bf4d3d80 DL |
118 | /* no locking - must be called when single threaded (e.g. at startup.) |
119 | * this restriction hopefully won't be a huge bother considering normal usage | |
120 | * scenarios... | |
121 | */ | |
5c25bd87 | 122 | void printfrr_ext_reg(const struct printfrr_ext *); |
bf4d3d80 DL |
123 | |
124 | #define printfrr_ext_autoreg_p(matchs, print_fn) \ | |
125 | static ssize_t print_fn(char *, size_t, const char *, int, \ | |
126 | const void *); \ | |
2b64873d | 127 | static const struct printfrr_ext _printext_##print_fn = { \ |
bf4d3d80 DL |
128 | .match = matchs, \ |
129 | .print_ptr = print_fn, \ | |
130 | }; \ | |
131 | static void _printreg_##print_fn(void) __attribute__((constructor)); \ | |
132 | static void _printreg_##print_fn(void) { \ | |
133 | printfrr_ext_reg(&_printext_##print_fn); \ | |
134 | } \ | |
135 | /* end */ | |
136 | ||
137 | #define printfrr_ext_autoreg_i(matchs, print_fn) \ | |
138 | static ssize_t print_fn(char *, size_t, const char *, int, uintmax_t); \ | |
2b64873d | 139 | static const struct printfrr_ext _printext_##print_fn = { \ |
bf4d3d80 DL |
140 | .match = matchs, \ |
141 | .print_int = print_fn, \ | |
142 | }; \ | |
143 | static void _printreg_##print_fn(void) __attribute__((constructor)); \ | |
144 | static void _printreg_##print_fn(void) { \ | |
145 | printfrr_ext_reg(&_printext_##print_fn); \ | |
146 | } \ | |
147 | /* end */ | |
5c25bd87 DL |
148 | |
149 | #endif |