lib/printf: integrate

Signed-off-by: David Lamparter <equinox@diac24.net>

1 files changed, 91 insertions, 0 deletions

diff --git a/lib/printfrr.h b/lib/printfrr.h
new file mode 100644
index 0000000000..f98527efd9
--- /dev/null
+++ b/lib/printfrr.h
@@ -0,0 +1,91 @@
+/*
+ * 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 "compiler.h"
+#include "memory.h"
+
+struct fbuf {
+	char *buf;
+	char *pos;
+	size_t len;
+};
+
+#define at(a, b) \
+	__attribute__((format(printf, 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);
+
+#undef at
+#undef atm
+
+struct printfrr_ext {
+	const char *match;
+	const char *opts;
+
+	union {
+		ssize_t (*print_ptr)(struct fbuf *out, const char *fmt, void *);
+		ssize_t (*print_int)(struct fbuf *out, const char *fmt, int);
+	};
+};
+
+void printfrr_ext_reg(const struct printfrr_ext *);
+void printfrr_ext_unreg(const struct printfrr_ext *);
+
+#endif