Add initial EQN support to mandoc. This parses, then throws away, data

between EQ and EN roff blocks.  EQN is different from TBL in that data
after .EQ is unilaterally considered an equation until an .EN.  Thus,
there's no need to jump through hoops in having table spans and so on.
This is ONLY the parse code framework in libroff.  EQN is not yet passed
into the backends.

7 files changed, 175 insertions, 12 deletions

diff --git a/Makefile b/Makefile
index a50054b6..9a5cd801 100644
--- a/Makefile
+++ b/Makefile
@@ -31,11 +31,11 @@ CFLAGS    += -g $(WFLAGS) $(VFLAGS) -DHAVE_CONFIG_H
 
 LINTFLAGS += $(VFLAGS)
 
-ROFFLNS    = roff.ln tbl.ln tbl_opts.ln tbl_layout.ln tbl_data.ln
+ROFFLNS    = roff.ln tbl.ln tbl_opts.ln tbl_layout.ln tbl_data.ln eqn.ln
 
-ROFFSRCS   = roff.c tbl.c tbl_opts.c tbl_layout.c tbl_data.c
+ROFFSRCS   = roff.c tbl.c tbl_opts.c tbl_layout.c tbl_data.c eqn.c
 
-ROFFOBJS   = roff.o tbl.o tbl_opts.o tbl_layout.o tbl_data.o
+ROFFOBJS   = roff.o tbl.o tbl_opts.o tbl_layout.o tbl_data.o eqn.o
 
 MANDOCLNS  = mandoc.ln
 
diff --git a/eqn.c b/eqn.c
new file mode 100644
index 00000000..83bade95
--- /dev/null
+++ b/eqn.c
@@ -0,0 +1,81 @@
+/*	$Id$ */
+/*
+ * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * 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.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "mandoc.h"
+#include "roff.h"
+#include "libmandoc.h"
+#include "libroff.h"
+
+/* ARGSUSED */
+enum rofferr
+eqn_read(struct eqn_node **epp, int ln, const char *p, int offs)
+{
+	size_t		 sz;
+	struct eqn_node	*ep;
+
+	if (0 == strcmp(p, ".EN")) {
+		*epp = NULL;
+		return(ROFF_EQN);
+	}
+
+	ep = *epp;
+
+	sz = strlen(&p[offs]);
+	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, &p[offs], ep->eqn.sz + 1);
+	return(ROFF_IGN);
+}
+
+struct eqn_node *
+eqn_alloc(int pos, int line)
+{
+	struct eqn_node	*p;
+
+	p = mandoc_calloc(1, sizeof(struct eqn_node));
+	p->line = line;
+	p->pos = pos;
+
+	return(p);
+}
+
+void
+eqn_end(struct eqn_node *e)
+{
+
+	/* Nothing to do. */
+}
+
+void
+eqn_free(struct eqn_node *p)
+{
+
+	free(p->eqn.data);
+	free(p);
+}
diff --git a/libroff.h b/libroff.h
index 9bf9bf9c..c882d487 100644
--- a/libroff.h
+++ b/libroff.h
@@ -43,6 +43,13 @@ struct	tbl_node {
 	struct tbl_node	 *next;
 };
 
+struct	eqn_node {
+	int		  pos; /* invocation column */
+	int		  line; /* invocation line */
+	struct eqn	  eqn;
+	struct eqn_node	 *next;
+};
+
 #define	TBL_MSG(tblp, type, line, col) \
 	(*(tblp)->msg)((type), (tblp)->data, (line), (col), NULL)
 
@@ -57,6 +64,10 @@ int		 tbl_data(struct tbl_node *, int, const char *);
 int		 tbl_cdata(struct tbl_node *, int, const char *);
 const struct tbl_span	*tbl_span(struct tbl_node *);
 void		 tbl_end(struct tbl_node *);
+struct eqn_node	*eqn_alloc(int, int);
+void		 eqn_end(struct eqn_node *);
+void		 eqn_free(struct eqn_node *);
+enum rofferr 	 eqn_read(struct eqn_node **, int, const char *, int);
 
 __END_DECLS
 
diff --git a/main.c b/main.c
index 1bf8712c..59063397 100644
--- a/main.c
+++ b/main.c
@@ -863,6 +863,8 @@ rerun:
 				else
 					mdoc_addspan(curp->mdoc, span);
 			}
+		} else if (ROFF_EQN == rr) {
+			assert(curp->man || curp->mdoc);
 		} else if (curp->man || curp->mdoc) {
 			rc = curp->man ?
 				man_parseln(curp->man, 
diff --git a/mandoc.h b/mandoc.h
index 704ec745..56d45ebc 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -267,6 +267,11 @@ struct	tbl_span {
 	struct tbl_span	 *next;
 };
 
+struct	eqn {
+	size_t		  sz;
+	char		 *data;
+};
+
 /*
  * Available registers (set in libroff, accessed elsewhere).
  */
diff --git a/roff.c b/roff.c
index b885a5f2..91e4dcbd 100644
--- a/roff.c
+++ b/roff.c
@@ -64,6 +64,8 @@ enum	rofft {
 	ROFF_TS,
 	ROFF_TE,
 	ROFF_T_,
+	ROFF_EQ,
+	ROFF_EN,
 	ROFF_cblock,
 	ROFF_ccond, /* FIXME: remove this. */
 	ROFF_USERDEF,
@@ -93,6 +95,9 @@ struct	roff {
 	struct tbl_node	*first_tbl; /* first table parsed */
 	struct tbl_node	*last_tbl; /* last table parsed */
 	struct tbl_node	*tbl; /* current table being parsed */
+	struct eqn_node	*last_eqn; /* last equation parsed */
+	struct eqn_node	*first_eqn; /* first equation parsed */
+	struct eqn_node	*eqn; /* current equation being parsed */
 };
 
 struct	roffnode {
@@ -151,6 +156,8 @@ static	void		 roff_setstr(struct roff *,
 static	enum rofferr	 roff_so(ROFF_ARGS);
 static	enum rofferr	 roff_TE(ROFF_ARGS);
 static	enum rofferr	 roff_TS(ROFF_ARGS);
+static	enum rofferr	 roff_EQ(ROFF_ARGS);
+static	enum rofferr	 roff_EN(ROFF_ARGS);
 static	enum rofferr	 roff_T_(ROFF_ARGS);
 static	enum rofferr	 roff_userdef(ROFF_ARGS);
 
@@ -189,6 +196,8 @@ static	struct roffmac	 roffs[ROFF_MAX] = {
 	{ "TS", roff_TS, NULL, NULL, 0, NULL },
 	{ "TE", roff_TE, NULL, NULL, 0, NULL },
 	{ "T&", roff_T_, NULL, NULL, 0, NULL },
+	{ "EQ", roff_EQ, NULL, NULL, 0, NULL },
+	{ "EN", roff_EN, NULL, NULL, 0, NULL },
 	{ ".", roff_cblock, NULL, NULL, 0, NULL },
 	{ "\\}", roff_ccond, NULL, NULL, 0, NULL },
 	{ NULL, roff_userdef, NULL, NULL, 0, NULL },
@@ -311,15 +320,22 @@ static void
 roff_free1(struct roff *r)
 {
 	struct tbl_node	*t;
+	struct eqn_node	*e;
 
-	while (r->first_tbl) {
-		t = r->first_tbl;
+	while (NULL != (t = r->first_tbl)) {
 		r->first_tbl = t->next;
 		tbl_free(t);
 	}
 
 	r->first_tbl = r->last_tbl = r->tbl = NULL;
 
+	while (NULL != (e = r->first_eqn)) {
+		r->first_eqn = e->next;
+		eqn_free(e);
+	}
+
+	r->first_eqn = r->last_eqn = r->eqn = NULL;
+
 	while (r->last)
 		roffnode_pop(r);
 
@@ -477,6 +493,8 @@ roff_parseln(struct roff *r, int ln, char **bufp,
 	 * First, if a scope is open and we're not a macro, pass the
 	 * text through the macro's filter.  If a scope isn't open and
 	 * we're not a macro, just let it through.
+	 * Finally, if there's an equation scope open, divert it into it
+	 * no matter our state.
 	 */
 
 	if (r->last && ! ROFF_CTL((*bufp)[pos])) {
@@ -485,18 +503,26 @@ roff_parseln(struct roff *r, int ln, char **bufp,
 		e = (*roffs[t].text)
 			(r, t, bufp, szp, ln, pos, pos, offs);
 		assert(ROFF_IGN == e || ROFF_CONT == e);
-		if (ROFF_CONT == e && r->tbl)
+		if (ROFF_CONT != e)
+			return(e);
+		if (r->eqn)
+			return(eqn_read(&r->eqn, ln, *bufp, *offs));
+		if (r->tbl)
 			return(tbl_read(r->tbl, ln, *bufp, *offs));
-		return(e);
+		return(ROFF_CONT);
 	} else if ( ! ROFF_CTL((*bufp)[pos])) {
+		if (r->eqn)
+			return(eqn_read(&r->eqn, ln, *bufp, *offs));
 		if (r->tbl)
 			return(tbl_read(r->tbl, ln, *bufp, *offs));
 		return(ROFF_CONT);
-	}
+	} else if (r->eqn)
+		return(eqn_read(&r->eqn, ln, *bufp, *offs));
 
 	/*
 	 * If a scope is open, go to the child handler for that macro,
 	 * as it may want to preprocess before doing anything with it.
+	 * Don't do so if an equation is open.
 	 */
 
 	if (r->last) {
@@ -532,6 +558,13 @@ roff_endparse(struct roff *r)
 		(*r->msg)(MANDOCERR_SCOPEEXIT, r->data,
 				r->last->line, r->last->col, NULL);
 
+	if (r->eqn) {
+		(*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
+				r->eqn->line, r->eqn->pos, NULL);
+		eqn_end(r->eqn);
+		r->eqn = NULL;
+	}
+
 	if (r->tbl) {
 		(*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
 				r->tbl->line, r->tbl->pos, NULL);
@@ -1140,6 +1173,33 @@ roff_T_(ROFF_ARGS)
 
 /* ARGSUSED */
 static enum rofferr
+roff_EQ(ROFF_ARGS)
+{
+	struct eqn_node	*e;
+
+	assert(NULL == r->eqn);
+	e = eqn_alloc(ppos, ln);
+
+	if (r->last_eqn)
+		r->last_eqn->next = e;
+	else
+		r->first_eqn = r->last_eqn = e;
+
+	r->eqn = r->last_eqn = e;
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
+roff_EN(ROFF_ARGS)
+{
+
+	(*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL);
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
 roff_TS(ROFF_ARGS)
 {
 	struct tbl_node	*t;
@@ -1240,7 +1300,6 @@ roff_userdef(ROFF_ARGS)
 	   ROFF_REPARSE : ROFF_APPEND);
 }
 
-
 static char *
 roff_getname(struct roff *r, char **cpp, int ln, int pos)
 {
@@ -1274,7 +1333,6 @@ roff_getname(struct roff *r, char **cpp, int ln, int pos)
 	return(name);
 }
 
-
 /*
  * Store *string into the user-defined string called *name.
  * In multiline mode, append to an existing entry and append '\n';
@@ -1344,7 +1402,6 @@ roff_setstr(struct roff *r, const char *name, const char *string,
 	*c = '\0';
 }
 
-
 static const char *
 roff_getstrn(const struct roff *r, const char *name, size_t len)
 {
@@ -1357,7 +1414,6 @@ roff_getstrn(const struct roff *r, const char *name, size_t len)
 	return(n ? n->string : NULL);
 }
 
-
 static void
 roff_freestr(struct roff *r)
 {
@@ -1379,3 +1435,10 @@ roff_span(const struct roff *r)
 	
 	return(r->tbl ? tbl_span(r->tbl) : NULL);
 }
+
+const struct eqn *
+roff_eqn(const struct roff *r)
+{
+	
+	return(r->last_eqn ? &r->last_eqn->eqn : NULL);
+}
diff --git a/roff.h b/roff.h
index d90a68f7..f8555539 100644
--- a/roff.h
+++ b/roff.h
@@ -25,6 +25,7 @@ enum	rofferr {
 	ROFF_SO, /* include another file */
 	ROFF_IGN, /* ignore current line */
 	ROFF_TBL, /* a table row was successfully parsed */
+	ROFF_EQN, /* an equation was successfully parsed */
 	ROFF_ERR /* badness: puke and stop */
 };