Basic reporting of .Xrs to manual pages that don't exist

in the base system, inspired by mdoclint(1).

We are able to do this because (1) the -mdoc parser, the -Tlint validator,
and the man(1) manual page lookup code are all in the same program
and (2) the mandoc.db(5) database format allows fast lookup.

Feedback from, previous versions tested by, and OK jmc@.

A few features will be added to this in the tree, step by step.

1 files changed, 112 insertions, 0 deletions

diff --git a/mandoc_xr.c b/mandoc_xr.c
new file mode 100644
index 00000000..d69c9c80
--- /dev/null
+++ b/mandoc_xr.c
@@ -0,0 +1,112 @@
+/*	$Id$ */
+/*
+ * Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
+ *
+ * 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.
+ */
+#include <sys/types.h>
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "mandoc_aux.h"
+#include "mandoc_ohash.h"
+#include "mandoc_xr.h"
+
+static struct ohash	 *xr_hash = NULL;
+static struct mandoc_xr	 *xr_first = NULL;
+static struct mandoc_xr	 *xr_last = NULL;
+
+static void		  mandoc_xr_clear(void);
+
+
+static void
+mandoc_xr_clear(void)
+{
+	struct mandoc_xr	*xr;
+	unsigned int		 slot;
+
+	if (xr_hash == NULL)
+		return;
+	for (xr = ohash_first(xr_hash, &slot); xr != NULL;
+	     xr = ohash_next(xr_hash, &slot))
+		free(xr);
+	ohash_delete(xr_hash);
+}
+
+void
+mandoc_xr_reset(void)
+{
+	if (xr_hash == NULL)
+		xr_hash = mandoc_malloc(sizeof(*xr_hash));
+	else
+		mandoc_xr_clear();
+	mandoc_ohash_init(xr_hash, 5,
+	    offsetof(struct mandoc_xr, hashkey));
+	xr_first = xr_last = NULL;
+}
+
+void
+mandoc_xr_add(const char *sec, const char *name, int line, int pos)
+{
+	struct mandoc_xr	 *xr;
+	const char		 *pend;
+	size_t			  ssz, nsz, tsz;
+	unsigned int		  slot;
+	uint32_t		  hv;
+
+	if (xr_hash == NULL)
+		return;
+
+	ssz = strlen(sec) + 1;
+	nsz = strlen(name) + 1;
+	tsz = ssz + nsz;
+	xr = mandoc_malloc(sizeof(*xr) + tsz);
+	xr->next = NULL;
+	xr->sec = xr->hashkey;
+	xr->name = xr->hashkey + ssz;
+	xr->line = line;
+	xr->pos = pos;
+	memcpy(xr->sec, sec, ssz);
+	memcpy(xr->name, name, nsz);
+
+	pend = xr->hashkey + tsz;
+	hv = ohash_interval(xr->hashkey, &pend);
+	slot = ohash_lookup_memory(xr_hash, xr->hashkey, tsz, hv);
+	if (ohash_find(xr_hash, slot) == NULL) {
+		ohash_insert(xr_hash, slot, xr);
+		if (xr_first == NULL)
+			xr_first = xr;
+		else
+			xr_last->next = xr;
+		xr_last = xr;
+	} else
+		free(xr);
+}
+
+struct mandoc_xr *
+mandoc_xr_get(void)
+{
+	return xr_first;
+}
+
+void
+mandoc_xr_free(void)
+{
+	mandoc_xr_clear();
+	free(xr_hash);
+	xr_hash = NULL;
+}