Support nested roff instructions:

* allow roff_parseln() to be re-run
* allow roff_parseln() to manipulate the line buffer offset
* support the offset in the man and mdoc libraries
* adapt .if, .ie, .el, .ig, .am* and .de* support
* interpret some instructions even in conditional-negative context
Coded by kristaps during the last day of the mandoc hackathon.

To avoid regressions in the OpenBSD tree, commit this together
with some small local additions:
* detect roff block end "\}" even on macro lines
* actually implement the ".if n" conditional
* ignore .ds, .rm and .tr in libroff

Also back my old .if/.ie/.el-handling out of libman, reverting:
man.h 1.15 man.c 1.25 man_macro.c 1.15 man_validate.c 1.19
man_action.c 1.15 man_term.c 1.28 man_html.c 1.9.

1 files changed, 31 insertions, 26 deletions

diff --git a/usr.bin/mandoc/mdoc.c b/usr.bin/mandoc/mdoc.c
index e5c8121963b..261edfc35a6 100644
--- a/usr.bin/mandoc/mdoc.c
+++ b/usr.bin/mandoc/mdoc.c
@@ -1,4 +1,4 @@
-/*	$Id: mdoc.c,v 1.52 2010/05/16 20:46:15 schwarze Exp $ */
+/*	$Id: mdoc.c,v 1.53 2010/05/20 00:58:02 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -146,9 +146,10 @@ static	struct mdoc_node *node_alloc(struct mdoc *, int, int,
 				enum mdoct, enum mdoc_type);
 static	int		  node_append(struct mdoc *, 
 				struct mdoc_node *);
-static	int		  mdoc_ptext(struct mdoc *, int, char *);
-static	int		  mdoc_pmacro(struct mdoc *, int, char *);
-static	int		  macrowarn(struct mdoc *, int, const char *);
+static	int		  mdoc_ptext(struct mdoc *, int, char *, int);
+static	int		  mdoc_pmacro(struct mdoc *, int, char *, int);
+static	int		  macrowarn(struct mdoc *, int, 
+				const char *, int);
 
 
 const struct mdoc_node *
@@ -280,16 +281,16 @@ mdoc_endparse(struct mdoc *m)
  * the macro (mdoc_pmacro()) or text parser (mdoc_ptext()).
  */
 int
-mdoc_parseln(struct mdoc *m, int ln, char *buf)
+mdoc_parseln(struct mdoc *m, int ln, char *buf, int offs)
 {
 
 	if (MDOC_HALT & m->flags)
 		return(0);
 
 	m->flags |= MDOC_NEWLINE;
-	return(('.' == *buf || '\'' == *buf) ? 
-			mdoc_pmacro(m, ln, buf) :
-			mdoc_ptext(m, ln, buf));
+	return(('.' == buf[offs] || '\'' == buf[offs]) ? 
+			mdoc_pmacro(m, ln, buf, offs) :
+			mdoc_ptext(m, ln, buf, offs));
 }
 
 
@@ -626,26 +627,28 @@ mdoc_node_delete(struct mdoc *m, struct mdoc_node *p)
  * control character.
  */
 static int
-mdoc_ptext(struct mdoc *m, int line, char *buf)
+mdoc_ptext(struct mdoc *m, int line, char *buf, int offs)
 {
 	char		*c, *ws, *end;
 
 	/* Ignore bogus comments. */
 
-	if ('\\' == buf[0] && '.' == buf[1] && '\"' == buf[2])
-		return(mdoc_pwarn(m, line, 0, EBADCOMMENT));
+	if ('\\' == buf[offs] && 
+			'.' == buf[offs + 1] && 
+			'"' == buf[offs + 2])
+		return(mdoc_pwarn(m, line, offs, EBADCOMMENT));
 
 	/* No text before an initial macro. */
 
 	if (SEC_NONE == m->lastnamed)
-		return(mdoc_perr(m, line, 0, ETEXTPROL));
+		return(mdoc_perr(m, line, offs, ETEXTPROL));
 
 	/*
 	 * Search for the beginning of unescaped trailing whitespace (ws)
 	 * and for the first character not to be output (end).
 	 */
 	ws = NULL;
-	for (c = end = buf; *c; c++) {
+	for (c = end = buf + offs; *c; c++) {
 		switch (*c) {
 		case ' ':
 			if (NULL == ws)
@@ -683,7 +686,7 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 		if ( ! mdoc_pwarn(m, line, (int)(ws-buf), ETAILWS))
 			return(0);
 
-	if ('\0' == *buf && ! (MDOC_LITERAL & m->flags)) {
+	if ('\0' == buf[offs] && ! (MDOC_LITERAL & m->flags)) {
 		if ( ! mdoc_pwarn(m, line, (int)(c-buf), ENOBLANK))
 			return(0);
 
@@ -692,14 +695,14 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 		 * blank lines aren't allowed, but enough manuals assume this
 		 * behaviour that we want to work around it.
 		 */
-		if ( ! mdoc_elem_alloc(m, line, 0, MDOC_Pp, NULL))
+		if ( ! mdoc_elem_alloc(m, line, offs, MDOC_Pp, NULL))
 			return(0);
 
 		m->next = MDOC_NEXT_SIBLING;
 		return(1);
 	}
 
-	if ( ! mdoc_word_alloc(m, line, 0, buf))
+	if ( ! mdoc_word_alloc(m, line, offs, buf+offs))
 		return(0);
 
 	if (MDOC_LITERAL & m->flags)
@@ -713,7 +716,7 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 
 	assert(buf < end);
 
-	if (mandoc_eos(buf, (size_t)(end-buf)))
+	if (mandoc_eos(buf+offs, (size_t)(end-buf-offs)))
 		m->last->flags |= MDOC_EOS;
 
 	return(1);
@@ -721,12 +724,12 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 
 
 static int
-macrowarn(struct mdoc *m, int ln, const char *buf)
+macrowarn(struct mdoc *m, int ln, const char *buf, int offs)
 {
 	if ( ! (MDOC_IGN_MACRO & m->pflags))
-		return(mdoc_verr(m, ln, 0, "unknown macro: %s%s", 
+		return(mdoc_verr(m, ln, offs, "unknown macro: %s%s", 
 				buf, strlen(buf) > 3 ? "..." : ""));
-	return(mdoc_vwarn(m, ln, 0, "unknown macro: %s%s",
+	return(mdoc_vwarn(m, ln, offs, "unknown macro: %s%s",
 				buf, strlen(buf) > 3 ? "..." : ""));
 }
 
@@ -736,7 +739,7 @@ macrowarn(struct mdoc *m, int ln, const char *buf)
  * character.
  */
 int
-mdoc_pmacro(struct mdoc *m, int ln, char *buf)
+mdoc_pmacro(struct mdoc *m, int ln, char *buf, int offs)
 {
 	enum mdoct	tok;
 	int		i, j, sv;
@@ -744,10 +747,12 @@ mdoc_pmacro(struct mdoc *m, int ln, char *buf)
 
 	/* Empty lines are ignored. */
 
-	if ('\0' == buf[1])
+	offs++;
+
+	if ('\0' == buf[offs])
 		return(1);
 
-	i = 1;
+	i = offs;
 
 	/* Accept whitespace after the initial control char. */
 
@@ -776,16 +781,16 @@ mdoc_pmacro(struct mdoc *m, int ln, char *buf)
 		return(mdoc_perr(m, ln, i, EPRINT));
 	}
 
-	mac[j] = 0;
+	mac[j] = '\0';
 
 	if (j == 4 || j < 2) {
-		if ( ! macrowarn(m, ln, mac))
+		if ( ! macrowarn(m, ln, mac, sv))
 			goto err;
 		return(1);
 	} 
 	
 	if (MDOC_MAX == (tok = mdoc_hash_find(mac))) {
-		if ( ! macrowarn(m, ln, mac))
+		if ( ! macrowarn(m, ln, mac, sv))
 			goto err;
 		return(1);
 	}