Allow roff_parseln() to be re-run.

Allow roff_parseln() to manipulate the line buffer offset.  This is used
in situations like `.ie n .TH FOO 1' or `.ie n .ie n', where the line
buffer offset is recalculated then the roff parser re-run.
Fix mdoc_parseln() and man_parseln() to accept the initial line offset.
WARNING: backed-out ALL roff macros whilst accomodating for how roff
handles multi-line conditionals (in short, re-running the parser).

1 files changed, 30 insertions, 8 deletions

diff --git a/main.c b/main.c
index d7bac760..65fde5c3 100644
--- a/main.c
+++ b/main.c
@@ -386,7 +386,7 @@ static void
 fdesc(struct curparse *curp)
 {
 	struct buf	 ln, blk;
-	int		 i, pos, lnn, lnn_start, with_mmap;
+	int		 i, pos, lnn, lnn_start, with_mmap, of;
 	enum rofferr	 re;
 	struct man	*man;
 	struct mdoc	*mdoc;
@@ -467,22 +467,42 @@ fdesc(struct curparse *curp)
 				goto bailout;
 		ln.buf[pos] = '\0';
 
-		re = roff_parseln(roff, lnn_start, &ln.buf, &ln.sz);
+		/*
+		 * A significant amount of complexity is contained by
+		 * the roff preprocessor.  It's line-oriented but can be
+		 * expressed on one line, so we need at times to
+		 * readjust our starting point and re-run it.  The roff
+		 * preprocessor can also readjust the buffers with new
+		 * data, so we pass them in wholesale.
+		 */
+
+		of = 0;
+		do {
+			re = roff_parseln(roff, lnn_start, 
+					&ln.buf, &ln.sz, of, &of);
+		} while (ROFF_RERUN == re);
+
 		if (ROFF_IGN == re)
 			continue;
 		else if (ROFF_ERR == re)
 			goto bailout;
 
-		/* If unset, assign parser in pset(). */
+		/*
+		 * If input parsers have not been allocated, do so now.
+		 * We keep these instanced betwen parsers, but set them
+		 * locally per parse routine since we can use different
+		 * parsers with each one.
+		 */
 
-		if ( ! (man || mdoc) && ! pset(ln.buf, pos, curp, &man, &mdoc))
-			goto bailout;
+		if ( ! (man || mdoc))
+			if ( ! pset(ln.buf + of, pos - of, curp, &man, &mdoc))
+				goto bailout;
 
-		/* Pass down into parsers. */
+		/* Lastly, push down into the parsers themselves. */
 
-		if (man && ! man_parseln(man, lnn_start, ln.buf))
+		if (man && ! man_parseln(man, lnn_start, ln.buf, of))
 			goto bailout;
-		if (mdoc && ! mdoc_parseln(mdoc, lnn_start, ln.buf))
+		if (mdoc && ! mdoc_parseln(mdoc, lnn_start, ln.buf, of))
 			goto bailout;
 	}
 
@@ -493,6 +513,8 @@ fdesc(struct curparse *curp)
 		goto bailout;
 	}
 
+	/* Clean up the parse routine ASTs. */
+
 	if (mdoc && ! mdoc_endparse(mdoc))
 		goto bailout;
 	if (man && ! man_endparse(man))