/*
* Copyright (c) 2019 David Lamparter, for NetDEF, Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _FRR_PRINTFRR_H
#define _FRR_PRINTFRR_H
#include <stddef.h>
#include <stdarg.h>
#include <stdint.h>
#include "compiler.h"
#include "memory.h"
#ifdef __cplusplus
extern "C" {
#endif
struct fbuf {
char *buf;
char *pos;
size_t len;
};
#define at(a, b) PRINTFRR(a, b)
#define atn(a, b) \
at(a, b) __attribute__((nonnull(1) _RET_NONNULL))
#define atm(a, b) \
atn(a, b) __attribute__((malloc))
/* return value is length needed for the full string (excluding \0) in all
* cases. The functions write as much as they can, but continue regardless,
* so the return value is independent of buffer length. Both bprintfrr and
* snprintf also accept NULL as output buffer.
*/
/* bprintfrr does NOT null terminate! use sparingly (only provided since it's
* the most direct interface) - useful for incrementally building long text
* (call bprintfrr repeatedly with the same buffer)
*/
ssize_t vbprintfrr(struct fbuf *out, const char *fmt, va_list) at(2, 0);
ssize_t bprintfrr(struct fbuf *out, const char *fmt, ...) at(2, 3);
/* these do null terminate like their snprintf cousins */
ssize_t vsnprintfrr(char *out, size_t sz, const char *fmt, va_list) at(3, 0);
ssize_t snprintfrr(char *out, size_t sz, const char *fmt, ...) at(3, 4);
/* c = continue / concatenate (append at the end of the string)
* return value is would-be string length (regardless of buffer length),
* i.e. includes already written chars */
ssize_t vcsnprintfrr(char *out, size_t sz, const char *fmt, va_list) at(3, 0);
ssize_t csnprintfrr(char *out, size_t sz, const char *fmt, ...) at(3, 4);
/* memory allocations don't fail in FRR, so you always get something here.
* (in case of error, returns a strdup of the format string) */
char *vasprintfrr(struct memtype *mt, const char *fmt, va_list) atm(2, 0);
char *asprintfrr(struct memtype *mt, const char *fmt, ...) atm(2, 3);
/* try to use provided buffer (presumably from stack), allocate if it's too
* short. Must call XFREE(mt, return value) if return value != out.
*/
char *vasnprintfrr(struct memtype *mt, char *out, size_t sz,
const char *fmt, va_list) atn(4, 0);
char *asnprintfrr(struct memtype *mt, char *out, size_t sz,
const char *fmt, ...) atn(4, 5);
#define printfrr(fmt, ...) \
do { \
char buf[256], *out; \
out = asnprintfrr(MTYPE_TMP, buf, sizeof(buf), fmt, \
##__VA_ARGS__); \
fputs(out, stdout); \
if (out != buf) \
XFREE(MTYPE_TMP, out); \
} while (0)
#undef at
#undef atm
#undef atn
/* extension specs must start with a capital letter (this is a restriction
* for both performance's and human understanding's sake.)
*
* Note that the entire thing mostly works because a letter directly following
* a %p print specifier is extremely unlikely to occur (why would you want to
* print "0x12345678HELLO"?) Normally, you'd expect spacing or punctuation
* after a placeholder. That also means that neither of those works well for
* extension purposes, e.g. "%p{foo}" is reasonable to see actually used.
*
* TODO: would be nice to support a "%pF%dF" specifier that consumes 2
* arguments, e.g. to pass an integer + a list of known values... can be
* done, but a bit tricky.
*/
#define printfrr_ext_char(ch) ((ch) >= 'A' && (ch) <= 'Z')
struct printfrr_ext {
/* embedded string to minimize cache line pollution */
char match[8];
/* both can be given, if not the code continues searching
* (you can do %pX and %dX in 2 different entries)
*
* return value: number of bytes consumed from the format string, so
* you can consume extra flags (e.g. register for "%pX", consume
* "%pXfoo" or "%pXbar" for flags.) Convention is to make those flags
* lowercase letters or numbers.
*
* bsz is a compile-time constant in printf; it's gonna be relatively
* small. This isn't designed to print Shakespeare from a pointer.
*
* prec is the precision specifier (the 999 in "%.999p") -1 means
* none given (value in the format string cannot be negative)
*/
ssize_t (*print_ptr)(char *buf, size_t bsz, const char *fmt, int prec,
const void *);
ssize_t (*print_int)(char *buf, size_t bsz, const char *fmt, int prec,
uintmax_t);
};
/* no locking - must be called when single threaded (e.g. at startup.)
* this restriction hopefully won't be a huge bother considering normal usage
* scenarios...
*/
void printfrr_ext_reg(const struct printfrr_ext *);
#define printfrr_ext_autoreg_p(matchs, print_fn) \
static ssize_t print_fn(char *, size_t, const char *, int, \
const void *); \
static const struct printfrr_ext _printext_##print_fn = { \
.match = matchs, \
.print_ptr = print_fn, \
}; \
static void _printreg_##print_fn(void) __attribute__((constructor)); \
static void _printreg_##print_fn(void) { \
printfrr_ext_reg(&_printext_##print_fn); \
} \
/* end */
#define printfrr_ext_autoreg_i(matchs, print_fn) \
static ssize_t print_fn(char *, size_t, const char *, int, uintmax_t); \
static const struct printfrr_ext _printext_##print_fn = { \
.match = matchs, \
.print_int = print_fn, \
}; \
static void _printreg_##print_fn(void) __attribute__((constructor)); \
static void _printreg_##print_fn(void) { \
printfrr_ext_reg(&_printext_##print_fn); \
} \
/* end */
#ifdef __cplusplus
}
#endif
#endif