===================================================================
RCS file: /cvs/mandoc/eqn.c,v
retrieving revision 1.7
retrieving revision 1.16
diff -u -p -r1.7 -r1.16
--- mandoc/eqn.c	2011/07/17 12:52:54	1.7
+++ mandoc/eqn.c	2011/07/21 13:18:24	1.16
@@ -1,4 +1,4 @@
-/*	$Id: eqn.c,v 1.7 2011/07/17 12:52:54 kristaps Exp $ */
+/*	$Id: eqn.c,v 1.16 2011/07/21 13:18:24 kristaps Exp $ */
 /*
  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -28,89 +28,96 @@
 #include "libmandoc.h"
 #include "libroff.h"
 
-static const char	*eqn_nexttok(struct mparse *, int, int,
-				const char **, size_t *);
+#define	EQN_NEST_MAX	 128 /* maximum nesting of defines */
+#define	EQN_MSG(t, x)	 mandoc_msg((t), (x)->parse, (x)->eqn.ln, (x)->eqn.pos, NULL)
 
+struct	eqnpart {
+	const char	*name;
+	size_t		 sz;
+	int		(*fp)(struct eqn_node *);
+};
+
+struct	eqnmark {
+	const char	*name;
+	size_t		 sz;
+};
+
+enum	eqnpartt {
+	EQN_DEFINE = 0,
+	EQN_SET,
+	EQN_UNDEF,
+	EQN__MAX
+};
+
+static	void		 eqn_box_free(struct eqn_box *);
+static	struct eqn_def	*eqn_def_find(struct eqn_node *, 
+				const char *, size_t);
+static	int		 eqn_do_define(struct eqn_node *);
+static	int		 eqn_do_set(struct eqn_node *);
+static	int		 eqn_do_undef(struct eqn_node *);
+static	const char	*eqn_nexttok(struct eqn_node *, size_t *);
+static	const char	*eqn_nextrawtok(struct eqn_node *, size_t *);
+static	const char	*eqn_next(struct eqn_node *, 
+				char, size_t *, int);
+static	int		 eqn_box(struct eqn_node *, 
+				struct eqn_box *, struct eqn_box **);
+
+static	const struct eqnpart eqnparts[EQN__MAX] = {
+	{ "define", 6, eqn_do_define }, /* EQN_DEFINE */
+	{ "set", 3, eqn_do_set }, /* EQN_SET */
+	{ "undef", 5, eqn_do_undef }, /* EQN_UNDEF */
+};
+
+static	const struct eqnmark eqnmarks[EQNMARK__MAX] = {
+	{ "", 0 }, /* EQNMARK_NONE */
+	{ "dot", 3 }, /* EQNMARK_DOT */
+	{ "dotdot", 6 }, /* EQNMARK_DOTDOT */
+	{ "hat", 3 }, /* EQNMARK_HAT */
+	{ "tilde", 5 }, /* EQNMARK_TILDE */
+	{ "vec", 3 }, /* EQNMARK_VEC */
+	{ "dyad", 4 }, /* EQNMARK_DYAD */
+	{ "bar", 3 }, /* EQNMARK_BAR */
+	{ "under", 5 }, /* EQNMARK_UNDER */
+};
+
 /* ARGSUSED */
 enum rofferr
 eqn_read(struct eqn_node **epp, int ln, 
 		const char *p, int pos, int *offs)
 {
-	size_t		  sz;
-	struct eqn_node	 *ep;
-	const char	 *start, *end;
-	int		  i;
+	size_t		 sz;
+	struct eqn_node	*ep;
+	enum rofferr	 er;
 
+	ep = *epp;
+
+	/*
+	 * If we're the terminating mark, unset our equation status and
+	 * validate the full equation.
+	 */
+
 	if (0 == strcmp(p, ".EN")) {
+		er = eqn_end(ep);
 		*epp = NULL;
-		return(ROFF_EQN);
+		return(er);
 	}
 
-	ep = *epp;
-	end = p + pos;
-	start = eqn_nexttok(ep->parse, ln, pos, &end, &sz);
+	/*
+	 * Build up the full string, replacing all newlines with regular
+	 * whitespace.
+	 */
 
-	if (NULL == start)
-		return(ROFF_IGN);
+	sz = strlen(p + pos) + 1;
+	ep->data = mandoc_realloc(ep->data, ep->sz + sz + 1);
 
-	if (6 == sz && 0 == strncmp("define", start, 6)) {
-		if (end && '"' == *end)
-			mandoc_msg(MANDOCERR_EQNQUOTE, 
-					ep->parse, ln, pos, NULL);
+	/* First invocation: nil terminate the string. */
 
-		start = eqn_nexttok(ep->parse, ln, pos, &end, &sz);
+	if (0 == ep->sz)
+		*ep->data = '\0';
 
-		for (i = 0; i < (int)ep->defsz; i++)  {
-			if (ep->defs[i].keysz != sz)
-				continue;
-			if (0 == strncmp(ep->defs[i].key, start, sz))
-				break;
-		}
-
-		/*
-		 * TODO: merge this code with roff_getstr().
-		 */
-
-		if (i == (int)ep->defsz) {
-			ep->defsz++;
-			ep->defs = mandoc_realloc
-				(ep->defs, ep->defsz * 
-				 sizeof(struct eqn_def));
-			ep->defs[i].keysz = sz;
-			ep->defs[i].key = mandoc_malloc(sz + 1);
-			memcpy(ep->defs[i].key, start, sz);
-			ep->defs[i].key[(int)sz] = '\0';
-			ep->defs[i].val = NULL;
-			ep->defs[i].valsz = 0;
-		}
-
-		start = eqn_nexttok(ep->parse, ln, pos, &end, &sz);
-
-		ep->defs[i].valsz = sz;
-		ep->defs[i].val = mandoc_realloc
-			(ep->defs[i].val, sz + 1);
-		memcpy(ep->defs[i].val, start, sz);
-		ep->defs[i].val[(int)sz] = '\0';
-
-		if ('\0' == *end)
-			return(ROFF_IGN);
-
-		*offs = end - (p + pos);
-		assert(*offs > 0);
-
-		return(ROFF_RERUN);
-	}  else
-		end = p + pos;
-
-	if (0 == (sz = strlen(end)))
-		return(ROFF_IGN);
-
-	ep->eqn.data = mandoc_realloc(ep->eqn.data, ep->eqn.sz + sz + 1);
-	if (0 == ep->eqn.sz)
-		*ep->eqn.data = '\0';
-
-	ep->eqn.sz += sz;
-	strlcat(ep->eqn.data, end, ep->eqn.sz + 1);
+	ep->sz += sz;
+	strlcat(ep->data, p + pos, ep->sz + 1);
+	strlcat(ep->data, " ", ep->sz + 1);
 	return(ROFF_IGN);
 }
 
@@ -121,80 +128,337 @@ eqn_alloc(int pos, int line, struct mparse *parse)
 
 	p = mandoc_calloc(1, sizeof(struct eqn_node));
 	p->parse = parse;
-	p->eqn.line = line;
+	p->eqn.ln = line;
 	p->eqn.pos = pos;
 
 	return(p);
 }
 
-/* ARGSUSED */
-void
-eqn_end(struct eqn_node *e)
+enum rofferr
+eqn_end(struct eqn_node *ep)
 {
+	struct eqn_box	*root, *last;
+	int		 c;
 
-	/* Nothing to do. */
+	ep->eqn.root = root = 
+		mandoc_calloc(1, sizeof(struct eqn_box));
+	root->type = EQN_ROOT;
+
+	if (0 == ep->sz)
+		return(ROFF_IGN);
+
+	/*
+	 * Run the parser.
+	 * If we return before reaching the end of our input, our scope
+	 * is still open somewhere.
+	 * If we return alright but don't have a symmetric scoping, then
+	 * something's not right either.
+	 * Otherwise, return the equation.
+	 */
+
+	if (0 == (c = eqn_box(ep, root, &last))) {
+		if (last != root) {
+			EQN_MSG(MANDOCERR_EQNSCOPE, ep);
+			c = 0;
+		}
+	} else if (c > 0)
+		EQN_MSG(MANDOCERR_EQNNSCOPE, ep);
+
+	return(0 == c ? ROFF_EQN : ROFF_IGN);
 }
 
+static int
+eqn_box(struct eqn_node *ep, struct eqn_box *last, struct eqn_box **sv)
+{
+	size_t		 sz;
+	const char	*start;
+	int		 c, i, nextc;
+	struct eqn_box	*bp;
+
+	/* 
+	 * Mark our last level of subexpression. 
+	 * Also mark whether that the next node should be a
+	 * subexpression node.
+	 */
+
+	*sv = last;
+	nextc = 1;
+again:
+	if (NULL == (start = eqn_nexttok(ep, &sz)))
+		return(0);
+
+	for (i = 0; i < (int)EQN__MAX; i++) {
+		if (eqnparts[i].sz != sz)
+			continue;
+		if (strncmp(eqnparts[i].name, start, sz))
+			continue;
+		if ( ! (*eqnparts[i].fp)(ep))
+			return(-1);
+
+		goto again;
+	} 
+
+	for (i = 0; i < (int)EQNMARK__MAX; i++) {
+		if (eqnmarks[i].sz != sz)
+			continue;
+		if (strncmp(eqnmarks[i].name, start, sz))
+			continue;
+		last->mark = (enum eqn_markt)i;
+		goto again;
+	}
+
+	/* Exit this [hopefully] subexpression. */
+
+	if (sz == 1 && 0 == strncmp("}", start, 1)) 
+		return(1);
+
+	bp = mandoc_calloc(1, sizeof(struct eqn_box));
+	if (nextc)
+		last->child = bp;
+	else
+		last->next = bp;
+
+	last = bp;
+
+	/* 
+	 * See if we're to open a new subexpression.
+	 * If so, mark our node as such and descend.
+	 */
+
+	if (sz == 1 && 0 == strncmp("{", start, 1)) {
+		bp->type = EQN_SUBEXPR;
+		c = eqn_box(ep, bp, sv);
+
+		nextc = 0;
+		goto again;
+	}
+
+	/* A regular text node. */
+
+	bp->type = EQN_TEXT;
+	bp->text = mandoc_malloc(sz + 1);
+	*bp->text = '\0';
+	strlcat(bp->text, start, sz + 1);
+
+	nextc = 0;
+	goto again;
+}
+
 void
 eqn_free(struct eqn_node *p)
 {
 	int		 i;
 
-	free(p->eqn.data);
+	eqn_box_free(p->eqn.root);
 
 	for (i = 0; i < (int)p->defsz; i++) {
 		free(p->defs[i].key);
 		free(p->defs[i].val);
 	}
 
+	free(p->data);
 	free(p->defs);
 	free(p);
 }
 
-/*
- * Return the current equation token setting "next" on the next one,
- * setting the token size in "sz".
- * This does the Right Thing for quoted strings, too.
- * Returns NULL if no more tokens exist.
- */
+static void
+eqn_box_free(struct eqn_box *bp)
+{
+
+	if (bp->child)
+		eqn_box_free(bp->child);
+	if (bp->next)
+		eqn_box_free(bp->next);
+
+	free(bp->text);
+	free(bp);
+}
+
 static const char *
-eqn_nexttok(struct mparse *mp, int ln, int pos,
-		const char **next, size_t *sz)
+eqn_nextrawtok(struct eqn_node *ep, size_t *sz)
 {
-	const char	*start;
-	int		 q;
 
-	start = *next;
+	return(eqn_next(ep, '"', sz, 0));
+}
+
+static const char *
+eqn_nexttok(struct eqn_node *ep, size_t *sz)
+{
+
+	return(eqn_next(ep, '"', sz, 1));
+}
+
+static const char *
+eqn_next(struct eqn_node *ep, char quote, size_t *sz, int repl)
+{
+	char		*start, *next;
+	int		 q, diff, lim;
+	size_t		 sv, ssz;
+	struct eqn_def	*def;
+
+	if (NULL == sz)
+		sz = &ssz;
+
+	lim = 0;
+	sv = ep->cur;
+again:
+	/* Prevent self-definitions. */
+
+	if (lim >= EQN_NEST_MAX) {
+		EQN_MSG(MANDOCERR_EQNNEST, ep);
+		return(NULL);
+	}
+
+	ep->cur = sv;
+	start = &ep->data[(int)ep->cur];
 	q = 0;
 
 	if ('\0' == *start)
 		return(NULL);
 
-	if ('"' == *start) {
-		start++;
+	if (quote == *start) {
+		ep->cur++;
 		q = 1;
 	}
 
-	*next = q ? strchr(start, '"') : strchr(start, ' ');
+	start = &ep->data[(int)ep->cur];
+	next = q ? strchr(start, quote) : strchr(start, ' ');
 
-	if (NULL != *next) {
-		*sz = (size_t)(*next - start);
+	if (NULL != next) {
+		*sz = (size_t)(next - start);
+		ep->cur += *sz;
 		if (q)
-			(*next)++;
-		while (' ' == **next)
-			(*next)++;
+			ep->cur++;
+		while (' ' == ep->data[(int)ep->cur])
+			ep->cur++;
 	} else {
-		/*
-		 * XXX: groff gets confused by this and doesn't always
-		 * do the "right thing" (just terminate it and warn
-		 * about it).
-		 */
 		if (q)
-			mandoc_msg(MANDOCERR_BADQUOTE, 
-					mp, ln, pos, NULL);
-		*next = strchr(start, '\0');
-		*sz = (size_t)(*next - start);
+			EQN_MSG(MANDOCERR_BADQUOTE, ep);
+		next = strchr(start, '\0');
+		*sz = (size_t)(next - start);
+		ep->cur += *sz;
 	}
 
+	/* Quotes aren't expanded for values. */
+
+	if (q || ! repl)
+		return(start);
+
+	if (NULL != (def = eqn_def_find(ep, start, *sz))) {
+		diff = def->valsz - *sz;
+
+		if (def->valsz > *sz) {
+			ep->sz += diff;
+			ep->data = mandoc_realloc(ep->data, ep->sz + 1);
+			ep->data[ep->sz] = '\0';
+			start = &ep->data[(int)sv];
+		}
+
+		diff = def->valsz - *sz;
+		memmove(start + *sz + diff, start + *sz, 
+				(strlen(start) - *sz) + 1);
+		memcpy(start, def->val, def->valsz);
+		goto again;
+	}
+
 	return(start);
+}
+
+static int
+eqn_do_set(struct eqn_node *ep)
+{
+	const char	*start;
+
+	if (NULL == (start = eqn_nextrawtok(ep, NULL)))
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+	else if (NULL == (start = eqn_nextrawtok(ep, NULL)))
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+	else
+		return(1);
+
+	return(0);
+}
+
+static int
+eqn_do_define(struct eqn_node *ep)
+{
+	const char	*start;
+	size_t		 sz;
+	struct eqn_def	*def;
+	int		 i;
+
+	if (NULL == (start = eqn_nextrawtok(ep, &sz))) {
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+		return(0);
+	}
+
+	/* 
+	 * Search for a key that already exists. 
+	 * Create a new key if none is found.
+	 */
+
+	if (NULL == (def = eqn_def_find(ep, start, sz))) {
+		/* Find holes in string array. */
+		for (i = 0; i < (int)ep->defsz; i++)
+			if (0 == ep->defs[i].keysz)
+				break;
+
+		if (i == (int)ep->defsz) {
+			ep->defsz++;
+			ep->defs = mandoc_realloc
+				(ep->defs, ep->defsz * 
+				 sizeof(struct eqn_def));
+			ep->defs[i].key = ep->defs[i].val = NULL;
+		}
+
+		ep->defs[i].keysz = sz;
+		ep->defs[i].key = mandoc_realloc
+			(ep->defs[i].key, sz + 1);
+
+		memcpy(ep->defs[i].key, start, sz);
+		ep->defs[i].key[(int)sz] = '\0';
+		def = &ep->defs[i];
+	}
+
+	start = eqn_next(ep, ep->data[(int)ep->cur], &sz, 0);
+
+	if (NULL == start) {
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+		return(0);
+	}
+
+	def->valsz = sz;
+	def->val = mandoc_realloc(def->val, sz + 1);
+	memcpy(def->val, start, sz);
+	def->val[(int)sz] = '\0';
+	return(1);
+}
+
+static int
+eqn_do_undef(struct eqn_node *ep)
+{
+	const char	*start;
+	struct eqn_def	*def;
+	size_t		 sz;
+
+	if (NULL == (start = eqn_nextrawtok(ep, &sz))) {
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+		return(0);
+	} else if (NULL != (def = eqn_def_find(ep, start, sz)))
+		def->keysz = 0;
+
+	return(1);
+}
+
+static struct eqn_def *
+eqn_def_find(struct eqn_node *ep, const char *key, size_t sz)
+{
+	int		 i;
+
+	for (i = 0; i < (int)ep->defsz; i++) 
+		if (ep->defs[i].keysz && ep->defs[i].keysz == sz &&
+				0 == strncmp(ep->defs[i].key, key, sz))
+			return(&ep->defs[i]);
+
+	return(NULL);
 }