provide a STYLE message when mandoc knows the file name and the extension

disagrees with the section number given in the .Dt or .TH macro;
feature suggested and patch tested by jmc@

7 files changed, 47 insertions, 11 deletions

diff --git a/man_validate.c b/man_validate.c
index cb814217..da2f1ee7 100644
--- a/man_validate.c
+++ b/man_validate.c
@@ -510,9 +510,14 @@ post_TH(CHKARGS)
 
 	if (n != NULL)
 		n = n->next;
-	if (n != NULL && n->string != NULL)
+	if (n != NULL && n->string != NULL) {
 		man->meta.msec = mandoc_strdup(n->string);
-	else {
+		if (man->filesec != '\0' &&
+		    man->filesec != *n->string &&
+		    *n->string >= '1' && *n->string <= '9')
+			mandoc_msg(MANDOCERR_MSEC_FILE, n->line, n->pos,
+			    "*.%c vs TH ... %c", man->filesec, *n->string);
+	} else {
 		man->meta.msec = mandoc_strdup("");
 		mandoc_msg(MANDOCERR_MSEC_MISSING,
 		    nb->line, nb->pos, "TH %s", man->meta.title);
diff --git a/mandoc.1 b/mandoc.1
index 7497ec15..5f10320e 100644
--- a/mandoc.1
+++ b/mandoc.1
@@ -1,7 +1,7 @@
-.\"	$Id$
+.\" $OpenBSD: mandoc.1,v 1.166 2020/02/15 15:28:01 schwarze Exp $
 .\"
-.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2012, 2014-2020 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2009, 2010, 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
@@ -1078,6 +1078,20 @@ macro lacks the mandatory section argument.
 The section number in a
 .Ic \&Dt
 line is invalid, but still used.
+.It Sy "filename/section mismatch"
+.Pq mdoc , man
+The name of the input file being processed is known and its file
+name extension starts with a non-zero digit, but the
+.Ic \&Dt
+or
+.Ic \&TH
+macro contains a
+.Ar section
+argument that starts with a different non-zero digit.
+The
+.Ar section
+argument is used as provided anyway.
+Consider checking whether the file name or the argument need a correction.
 .It Sy "missing date, using \(dq\(dq"
 .Pq mdoc, man
 The document was parsed as
diff --git a/mandoc.h b/mandoc.h
index 12c0040a..0cacb4b5 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -84,6 +84,7 @@ enum	mandocerr {
 	MANDOCERR_TH_NOTITLE, /* missing manual title, using "": [macro] */
 	MANDOCERR_MSEC_MISSING, /* missing manual section, using "": macro */
 	MANDOCERR_MSEC_BAD, /* unknown manual section: Dt ... section */
+	MANDOCERR_MSEC_FILE, /* filename/section mismatch: ... */
 	MANDOCERR_DATE_MISSING, /* missing date, using "": [macro] */
 	MANDOCERR_DATE_BAD, /* cannot parse date, using it verbatim: date */
 	MANDOCERR_DATE_FUTURE, /* date in the future, using it anyway: date */
diff --git a/mandoc_msg.c b/mandoc_msg.c
index 8ce4ede9..318a219e 100644
--- a/mandoc_msg.c
+++ b/mandoc_msg.c
@@ -1,7 +1,7 @@
-/*	$Id$ */
+/* $OpenBSD: mandoc_msg.c,v 1.8 2020/01/19 17:59:01 schwarze Exp $ */
 /*
- * Copyright (c) 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014-2020 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010, 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
@@ -14,6 +14,8 @@
  * 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.
+ *
+ * Implementation of warning and error messages for mandoc(1).
  */
 #include "config.h"
 
@@ -83,6 +85,7 @@ static	const char *const type_message[MANDOCERR_MAX] = {
 	"missing manual title, using \"\"",
 	"missing manual section, using \"\"",
 	"unknown manual section",
+	"filename/section mismatch",
 	"missing date, using \"\"",
 	"cannot parse date, using it verbatim",
 	"date in the future, using it anyway",
diff --git a/mdoc_validate.c b/mdoc_validate.c
index fa0ada83..95db41cb 100644
--- a/mdoc_validate.c
+++ b/mdoc_validate.c
@@ -2765,8 +2765,14 @@ post_dt(POST_ARGS)
 		mandoc_msg(MANDOCERR_MSEC_BAD,
 		    nn->line, nn->pos, "Dt ... %s", nn->string);
 		mdoc->meta.vol = mandoc_strdup(nn->string);
-	} else
+	} else {
 		mdoc->meta.vol = mandoc_strdup(cp);
+		if (mdoc->filesec != '\0' &&
+		    mdoc->filesec != *nn->string &&
+		    *nn->string >= '1' && *nn->string <= '9')
+			mandoc_msg(MANDOCERR_MSEC_FILE, nn->line, nn->pos,
+			    "*.%c vs Dt ... %c", mdoc->filesec, *nn->string);
+	}
 
 	/* Optional third argument: architecture. */
 
diff --git a/read.c b/read.c
index 587dfe2a..f2790de5 100644
--- a/read.c
+++ b/read.c
@@ -554,7 +554,7 @@ mparse_readfd(struct mparse *curp, int fd, const char *filename)
 
 	struct buf	 blk;
 	struct buf	*save_primary;
-	const char	*save_filename;
+	const char	*save_filename, *cp;
 	size_t		 offset;
 	int		 save_filenc, save_lineno;
 	int		 with_mmap;
@@ -562,7 +562,13 @@ mparse_readfd(struct mparse *curp, int fd, const char *filename)
 	if (recursion_depth > 64) {
 		mandoc_msg(MANDOCERR_ROFFLOOP, curp->line, 0, NULL);
 		return;
-	}
+	} else if (recursion_depth == 0 &&
+	    (cp = strrchr(filename, '.')) != NULL &&
+            cp[1] >= '1' && cp[1] <= '9')
+                curp->man->filesec = cp[1];
+        else
+                curp->man->filesec = '\0';
+
 	if (read_whole_file(curp, fd, &blk, &with_mmap) == -1)
 		return;
 
diff --git a/roff_int.h b/roff_int.h
index 63da38df..e0700a74 100644
--- a/roff_int.h
+++ b/roff_int.h
@@ -1,7 +1,7 @@
-/*	$Id$	*/
+/* $OpenBSD: roff_int.h,v 1.16 2019/01/05 00:36:46 schwarze Exp $	*/
 /*
+ * Copyright (c) 2013-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2013-2015, 2017-2019 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
@@ -59,6 +59,7 @@ struct	roff_man {
 	enum roff_sec	  lastsec; /* Last section seen. */
 	enum roff_sec	  lastnamed; /* Last standard section seen. */
 	enum roff_next	  next;    /* Where to put the next node. */
+	char		  filesec; /* Section digit in the file name. */
 };