diff --git a/contrib/nvi/build/Makefile.in b/contrib/nvi/build/Makefile.in
index 54025e7d3b9d..d9c260988f98 100644
--- a/contrib/nvi/build/Makefile.in
+++ b/contrib/nvi/build/Makefile.in
@@ -3,7 +3,7 @@
 srcdir=	@srcdir@/..
 CC=	@CC@
 OPTFLAG=@OPTFLAG@
-CFLAGS=	-c $(OPTFLAG) @CFLAGS@ -I. -I$(srcdir)/include @CPPFLAGS@
+CFLAGS=	-c $(OPTFLAG) @CFLAGS@ -I. -I$(srcdir)/include @CPPFLAGS@ -DGTAGS
 LDFLAGS=@LDFLAGS@
 PERL=	@vi_cv_path_perl@
 PERLLIB=@vi_cv_perllib@
diff --git a/contrib/nvi/common/main.c b/contrib/nvi/common/main.c
index 6fb2ed1fe2f0..7e9580389dbe 100644
--- a/contrib/nvi/common/main.c
+++ b/contrib/nvi/common/main.c
@@ -64,6 +64,9 @@ editor(gp, argc, argv)
 	size_t len;
 	u_int flags;
 	int ch, flagchk, lflag, secure, startup, readonly, rval, silent;
+#ifdef GTAGS
+	int gtags = 0;
+#endif
 	char *tag_f, *wsizearg, path[256];
 
 	/* Initialize the busy routine, if not defined by the screen. */
@@ -113,10 +116,18 @@ editor(gp, argc, argv)
 	/* Set the file snapshot flag. */
 	F_SET(gp, G_SNAPSHOT);
 
+#ifdef GTAGS
+#ifdef DEBUG
+	while ((ch = getopt(argc, argv, "c:D:eFGlRrSsT:t:vw:")) != EOF)
+#else
+	while ((ch = getopt(argc, argv, "c:eFGlRrSst:vw:")) != EOF)
+#endif
+#else
 #ifdef DEBUG
 	while ((ch = getopt(argc, argv, "c:D:eFlRrSsT:t:vw:")) != EOF)
 #else
 	while ((ch = getopt(argc, argv, "c:eFlRrSst:vw:")) != EOF)
+#endif
 #endif
 		switch (ch) {
 		case 'c':		/* Run the command. */
@@ -154,6 +165,11 @@ editor(gp, argc, argv)
 		case 'F':		/* No snapshot. */
 			F_CLR(gp, G_SNAPSHOT);
 			break;
+#ifdef GTAGS
+		case 'G':		/* gtags mode. */
+			gtags = 1;
+			break;
+#endif
 		case 'l':		/* Set lisp, showmatch options. */
 			lflag = 1;
 			break;
@@ -252,6 +268,10 @@ editor(gp, argc, argv)
 	}
 	if (readonly)
 		*oargp++ = O_READONLY;
+#ifdef GTAGS
+	if (gtags)
+		*oargp++ = O_GTAGSMODE;
+#endif
 	if (secure)
 		*oargp++ = O_SECURE;
 	*oargp = -1;			/* Options initialization. */
diff --git a/contrib/nvi/common/options.c b/contrib/nvi/common/options.c
index 4d4f768b1634..fe310fc89d91 100644
--- a/contrib/nvi/common/options.c
+++ b/contrib/nvi/common/options.c
@@ -80,6 +80,10 @@ OPTLIST const optlist[] = {
 	{"filec",	NULL,		OPT_STR,	0},
 /* O_FLASH	    HPUX */
 	{"flash",	NULL,		OPT_1BOOL,	0},
+#ifdef GTAGS
+/* O_GTAGSMODE      FreeBSD2.2 */
+	{"gtagsmode",	NULL,		OPT_0BOOL,	0},
+#endif
 /* O_HARDTABS	    4BSD */
 	{"hardtabs",	NULL,		OPT_NUM,	0},
 /* O_ICLOWER	  4.4BSD */
@@ -244,6 +248,9 @@ static OABBREV const abbrev[] = {
 	{"eb",		O_ERRORBELLS},		/*     4BSD */
 	{"ed",		O_EDCOMPATIBLE},	/*     4BSD */
 	{"ex",		O_EXRC},		/* System V (undocumented) */
+#ifdef GTAGS
+	{"gt",		O_GTAGSMODE},		/* FreeBSD2.2 */
+#endif
 	{"ht",		O_HARDTABS},		/*     4BSD */
 	{"ic",		O_IGNORECASE},		/*     4BSD */
 	{"li",		O_LINES},		/*   4.4BSD */
diff --git a/contrib/nvi/docs/USD.doc/vi.man/vi.1 b/contrib/nvi/docs/USD.doc/vi.man/vi.1
index 22aee3e7e952..2275b942bf60 100644
--- a/contrib/nvi/docs/USD.doc/vi.man/vi.1
+++ b/contrib/nvi/docs/USD.doc/vi.man/vi.1
@@ -17,7 +17,7 @@ ex, vi, view \- text editors
 .SH SYNOPSIS
 .B ex
 [\c
-.B -eFRrSsv\c
+.B -eFGRrSsv\c
 ] [\c
 .BI -c " cmd"\c
 ] [\c
@@ -28,7 +28,7 @@ ex, vi, view \- text editors
 .br
 .B vi
 [\c
-.B -eFlRrSv\c
+.B -eFGlRrSv\c
 ] [\c
 .BI -c " cmd"\c
 ] [\c
@@ -39,7 +39,7 @@ ex, vi, view \- text editors
 .br
 .B view
 [\c
-.B -eFRrSv\c
+.B -eFGRrSv\c
 ] [\c
 .BI -c " cmd"\c
 ] [\c
@@ -121,6 +121,9 @@ the file during your edit session.)
 .B \-l
 Start editing with the lisp and showmatch options set.
 .TP
+.B \-G
+Start editing in gtags mode, as if the gtagsmode option was set.
+.TP
 .B \-R
 Start editing in read-only mode, as if the command name was
 .IR view ,
@@ -429,6 +432,8 @@ commands or cancel partial commands.
 .TP
 .B "<control-]>"
 Push a tag reference onto the tag stack.
+In gtagsmode, if at the first column of line,
+locate function references otherwise function definitions.
 .TP
 .B "<control-^>"
 Switch to the most recently edited file.
@@ -940,6 +945,9 @@ Grow or shrink the current screen.
 .B "rew[ind][!]"
 Rewind the argument list.
 .TP
+.B "rta[g][!] tagstring"
+Edit the file refering the specified tag. (Only in gtagsmode)
+.TP
 .B "se[t] [option[=[value]] ...] [nooption ...] [option? ...] [all]"
 Display or set editor options.
 .TP
@@ -1110,6 +1118,9 @@ command line.
 .B "flash [on]"
 Flash the screen instead of beeping the keyboard on error.
 .TP
+.B "gtagsmode, gt [off]"
+Use GTAGS and GRTAGS instead of tags.
+.TP
 .B "hardtabs, ht [8]"
 Set the spacing between hardware tab settings.
 .TP
diff --git a/contrib/nvi/ex/ex.h b/contrib/nvi/ex/ex.h
index 5870990b744e..f40be8ac9bfa 100644
--- a/contrib/nvi/ex/ex.h
+++ b/contrib/nvi/ex/ex.h
@@ -152,6 +152,9 @@ struct _excmd {
 #define	E_SEARCH_WMSG	0x01000000	/* Display search-wrapped message. */
 #define	E_USELASTCMD	0x02000000	/* Use the last command. */
 #define	E_VISEARCH	0x04000000	/* It's really a vi search command. */
+#ifdef GTAGS
+#define	E_REFERENCE	0x08000000	/* locate function references */
+#endif
 	u_int32_t flags;		/* Current flags. */
 };
 
diff --git a/contrib/nvi/ex/ex_cmd.c b/contrib/nvi/ex/ex_cmd.c
index 8f7fc8da7a13..8c9801df4291 100644
--- a/contrib/nvi/ex/ex_cmd.c
+++ b/contrib/nvi/ex/ex_cmd.c
@@ -302,6 +302,13 @@ EXCMDLIST const cmds[] = {
 	    "!",
 	    "rew[ind][!]",
 	    "re-edit all the files in the file argument list"},
+#ifdef GTAGS
+/* C_RTAG */
+	{"rtag",	ex_rtag_push,	E_NEWSCREEN,
+	    "!w1o",
+	    "[Rr]ta[g][!] [string]",
+	    "edit the file containing the tag"},
+#endif
 /*
  * !!!
  * Adding new commands starting with 's' may break the substitute command code
diff --git a/contrib/nvi/ex/ex_tag.c b/contrib/nvi/ex/ex_tag.c
index 461b1526ef00..7396b7a0bfcf 100644
--- a/contrib/nvi/ex/ex_tag.c
+++ b/contrib/nvi/ex/ex_tag.c
@@ -46,6 +46,10 @@ static char	*binary_search __P((char *, char *, char *));
 static int	 compare __P((char *, char *, char *));
 static void	 ctag_file __P((SCR *, TAGF *, char *, char **, size_t *));
 static int	 ctag_search __P((SCR *, char *, size_t, char *));
+#ifdef GTAGS
+static int	 getentry __P((char *, char *, char *, char *));
+static TAGQ	*gtag_slist __P((SCR *, char *, int));
+#endif
 static int	 ctag_sfile __P((SCR *, TAGF *, TAGQ *, char *));
 static TAGQ	*ctag_slist __P((SCR *, char *));
 static char	*linear_search __P((char *, char *, char *));
@@ -89,6 +93,25 @@ ex_tag_first(sp, tagarg)
 	return (0);
 }
 
+#ifdef GTAGS
+/*
+ * ex_rtag_push -- ^]
+ *		  :rtag[!] [string]
+ *
+ * Enter a new TAGQ context based on a ctag string.
+ *
+ * PUBLIC: int ex_rtag_push __P((SCR *, EXCMD *));
+ */
+int
+ex_rtag_push(sp, cmdp)
+	SCR *sp;
+	EXCMD *cmdp;
+{
+	F_SET(cmdp, E_REFERENCE);
+	return ex_tag_push(sp, cmdp);
+}
+#endif
+
 /*
  * ex_tag_push -- ^]
  *		  :tag[!] [string]
@@ -138,6 +161,12 @@ ex_tag_push(sp, cmdp)
 	}
 
 	/* Get the tag information. */
+#ifdef GTAGS
+	if (O_ISSET(sp, O_GTAGSMODE)) {
+		if ((tqp = gtag_slist(sp, exp->tag_last, F_ISSET(cmdp, E_REFERENCE))) == NULL)
+			return (1);
+	} else
+#endif
 	if ((tqp = ctag_slist(sp, exp->tag_last)) == NULL)
 		return (1);
 
@@ -969,6 +998,119 @@ notfound:			tag_msg(sp, TAG_SEARCH, tag);
 	return (0);
 }
 
+#ifdef GTAGS
+/*
+ * getentry --
+ *	get tag information from current line.
+ *
+ * gtags temporary file format.
+ * <tag>   <lineno>  <file>         <image>
+ *
+ * sample.
+ * +------------------------------------------------
+ * |main     30      main.c         main(argc, argv)
+ * |func     21      subr.c         func(arg)
+ */
+static int
+getentry(buf, tag, file, line)
+	char *buf, *tag, *file, *line;
+{
+	char *p;
+
+	p = tag;
+	while (*buf && !isspace(*buf))		/* tag name */
+		*p++ = *buf++;
+	*p = 0;
+	while (*buf && isspace(*buf))		/* skip blanks */
+		buf++;
+	p = line;
+	while (*buf && !isspace(*buf))		/* line no */
+		*p++ = *buf++;
+	*p = 0;
+	while (*buf && isspace(*buf))		/* skip blanks */
+		buf++;
+	p = file;
+	while (*buf && !isspace(*buf))		/* file name */
+		*p++ = *buf++;
+	*p = 0;
+
+	/* value check */
+	if (strlen(tag) && strlen(line) && strlen(file) && atoi(line) > 0)
+		return 1;	/* OK */
+	return 0;		/* ERROR */
+}
+
+/*
+ * gtag_slist --
+ *	Search the list of tags files for a tag, and return tag queue.
+ */
+static TAGQ *
+gtag_slist(sp, tag, ref)
+	SCR *sp;
+	char *tag;
+	int ref;
+{
+	EX_PRIVATE *exp;
+	TAGF *tfp;
+	TAGQ *tqp;
+	size_t len;
+	int echk;
+	TAG *tp;
+	static char name[80], file[200], line[10];
+	char command[200];
+	char buf[BUFSIZ+1];
+	FILE *fp;
+
+	/* Allocate and initialize the tag queue structure. */
+	len = strlen(tag);
+	CALLOC_GOTO(sp, tqp, TAGQ *, 1, sizeof(TAGQ) + len + 1);
+	CIRCLEQ_INIT(&tqp->tagq);
+	tqp->tag = tqp->buf;
+	memcpy(tqp->tag, tag, (tqp->tlen = len) + 1);
+
+	/*
+	 * Find the tag, only display missing file messages once, and
+	 * then only if we didn't find the tag.
+	 */
+	sprintf(command, "global -%s '%s'", ref ? "rx" : "x", tag);
+	if (fp = popen(command, "r")) {
+		while (fgets(buf, sizeof(buf), fp)) {
+			if (buf[strlen(buf)-1] == '\n')		/* chop(buf) */
+				buf[strlen(buf)-1] = 0;
+			else
+				while (fgetc(fp) != '\n')
+					;
+			if (getentry(buf, name, file, line) == 0) {
+				echk = 1;
+				F_SET(tfp, TAGF_ERR);
+				break;
+			}
+			CALLOC_GOTO(sp, tp,
+			    TAG *, 1, sizeof(TAG) + strlen(file) + 1 + strlen(line) + 1);
+			tp->fname = tp->buf;
+			strcpy(tp->fname, file);
+			tp->fnlen = strlen(file);
+			tp->search = tp->fname + tp->fnlen + 1;
+			strcpy(tp->search, line);
+			CIRCLEQ_INSERT_TAIL(&tqp->tagq, tp, q);
+		}
+		pclose(fp);
+	}
+
+	/* Check to see if we found anything. */
+	if (tqp->tagq.cqh_first == (void *)&tqp->tagq) {
+		msgq_str(sp, M_ERR, tag, "162|%s: tag not found");
+		free(tqp);
+		return (NULL);
+	}
+
+	tqp->current = tqp->tagq.cqh_first;
+	return (tqp);
+
+alloc_err:
+	return (NULL);
+}
+#endif
 /*
  * ctag_slist --
  *	Search the list of tags files for a tag, and return tag queue.
diff --git a/contrib/nvi/include/ex_def.h b/contrib/nvi/include/ex_def.h
index 2e69b4872f59..56e831d4565f 100644
--- a/contrib/nvi/include/ex_def.h
+++ b/contrib/nvi/include/ex_def.h
@@ -47,32 +47,33 @@
 #define C_RECOVER 46
 #define C_RESIZE 47
 #define C_REWIND 48
-#define C_SUBSTITUTE 49
-#define C_SCRIPT 50
-#define C_SET 51
-#define C_SHELL 52
-#define C_SOURCE 53
-#define C_STOP 54
-#define C_SUSPEND 55
-#define C_T 56
-#define C_TAG 57
-#define C_TAGNEXT 58
-#define C_TAGPOP 59
-#define C_TAGPREV 60
-#define C_TAGTOP 61
-#define C_TCLCMD 62
-#define C_UNDO 63
-#define C_UNABBREVIATE 64
-#define C_UNMAP 65
-#define C_V 66
-#define C_VERSION 67
-#define C_VISUAL_EX 68
-#define C_VISUAL_VI 69
-#define C_VIUSAGE 70
-#define C_WRITE 71
-#define C_WN 72
-#define C_WQ 73
-#define C_XIT 74
-#define C_YANK 75
-#define C_Z 76
-#define C_SUBTILDE 77
+#define C_RTAG 49
+#define C_SUBSTITUTE 50
+#define C_SCRIPT 51
+#define C_SET 52
+#define C_SHELL 53
+#define C_SOURCE 54
+#define C_STOP 55
+#define C_SUSPEND 56
+#define C_T 57
+#define C_TAG 58
+#define C_TAGNEXT 59
+#define C_TAGPOP 60
+#define C_TAGPREV 61
+#define C_TAGTOP 62
+#define C_TCLCMD 63
+#define C_UNDO 64
+#define C_UNABBREVIATE 65
+#define C_UNMAP 66
+#define C_V 67
+#define C_VERSION 68
+#define C_VISUAL_EX 69
+#define C_VISUAL_VI 70
+#define C_VIUSAGE 71
+#define C_WRITE 72
+#define C_WN 73
+#define C_WQ 74
+#define C_XIT 75
+#define C_YANK 76
+#define C_Z 77
+#define C_SUBTILDE 78
diff --git a/contrib/nvi/include/ex_extern.h b/contrib/nvi/include/ex_extern.h
index ed01701f1185..ce09b1ca9746 100644
--- a/contrib/nvi/include/ex_extern.h
+++ b/contrib/nvi/include/ex_extern.h
@@ -89,6 +89,7 @@ int re_compile __P((SCR *,
     char *, size_t, char **, size_t *, regex_t *, u_int));
 void re_error __P((SCR *, int, regex_t *));
 int ex_tag_first __P((SCR *, char *));
+int ex_rtag_push __P((SCR *, EXCMD *));
 int ex_tag_push __P((SCR *, EXCMD *));
 int ex_tag_next __P((SCR *, EXCMD *));
 int ex_tag_prev __P((SCR *, EXCMD *));
diff --git a/contrib/nvi/include/options_def.h b/contrib/nvi/include/options_def.h
index 089fa7f4ea4c..d2e637cb7a2f 100644
--- a/contrib/nvi/include/options_def.h
+++ b/contrib/nvi/include/options_def.h
@@ -16,64 +16,65 @@
 #define O_EXTENDED 15
 #define O_FILEC 16
 #define O_FLASH 17
-#define O_HARDTABS 18
-#define O_ICLOWER 19
-#define O_IGNORECASE 20
-#define O_KEYTIME 21
-#define O_LEFTRIGHT 22
-#define O_LINES 23
-#define O_LISP 24
-#define O_LIST 25
-#define O_LOCKFILES 26
-#define O_MAGIC 27
-#define O_MATCHTIME 28
-#define O_MESG 29
-#define O_MODELINE 30
-#define O_MSGCAT 31
-#define O_NOPRINT 32
-#define O_NUMBER 33
-#define O_OCTAL 34
-#define O_OPEN 35
-#define O_OPTIMIZE 36
-#define O_PARAGRAPHS 37
-#define O_PATH 38
-#define O_PRINT 39
-#define O_PROMPT 40
-#define O_READONLY 41
-#define O_RECDIR 42
-#define O_REDRAW 43
-#define O_REMAP 44
-#define O_REPORT 45
-#define O_RULER 46
-#define O_SCROLL 47
-#define O_SEARCHINCR 48
-#define O_SECTIONS 49
-#define O_SECURE 50
-#define O_SHELL 51
-#define O_SHELLMETA 52
-#define O_SHIFTWIDTH 53
-#define O_SHOWMATCH 54
-#define O_SHOWMODE 55
-#define O_SIDESCROLL 56
-#define O_SLOWOPEN 57
-#define O_SOURCEANY 58
-#define O_TABSTOP 59
-#define O_TAGLENGTH 60
-#define O_TAGS 61
-#define O_TERM 62
-#define O_TERSE 63
-#define O_TILDEOP 64
-#define O_TIMEOUT 65
-#define O_TTYWERASE 66
-#define O_VERBOSE 67
-#define O_W1200 68
-#define O_W300 69
-#define O_W9600 70
-#define O_WARN 71
-#define O_WINDOW 72
-#define O_WINDOWNAME 73
-#define O_WRAPLEN 74
-#define O_WRAPMARGIN 75
-#define O_WRAPSCAN 76
-#define O_WRITEANY 77
-#define O_OPTIONCOUNT 78
+#define O_GTAGSMODE 18
+#define O_HARDTABS 19
+#define O_ICLOWER 20
+#define O_IGNORECASE 21
+#define O_KEYTIME 22
+#define O_LEFTRIGHT 23
+#define O_LINES 24
+#define O_LISP 25
+#define O_LIST 26
+#define O_LOCKFILES 27
+#define O_MAGIC 28
+#define O_MATCHTIME 29
+#define O_MESG 30
+#define O_MODELINE 31
+#define O_MSGCAT 32
+#define O_NOPRINT 33
+#define O_NUMBER 34
+#define O_OCTAL 35
+#define O_OPEN 36
+#define O_OPTIMIZE 37
+#define O_PARAGRAPHS 38
+#define O_PATH 39
+#define O_PRINT 40
+#define O_PROMPT 41
+#define O_READONLY 42
+#define O_RECDIR 43
+#define O_REDRAW 44
+#define O_REMAP 45
+#define O_REPORT 46
+#define O_RULER 47
+#define O_SCROLL 48
+#define O_SEARCHINCR 49
+#define O_SECTIONS 50
+#define O_SECURE 51
+#define O_SHELL 52
+#define O_SHELLMETA 53
+#define O_SHIFTWIDTH 54
+#define O_SHOWMATCH 55
+#define O_SHOWMODE 56
+#define O_SIDESCROLL 57
+#define O_SLOWOPEN 58
+#define O_SOURCEANY 59
+#define O_TABSTOP 60
+#define O_TAGLENGTH 61
+#define O_TAGS 62
+#define O_TERM 63
+#define O_TERSE 64
+#define O_TILDEOP 65
+#define O_TIMEOUT 66
+#define O_TTYWERASE 67
+#define O_VERBOSE 68
+#define O_W1200 69
+#define O_W300 70
+#define O_W9600 71
+#define O_WARN 72
+#define O_WINDOW 73
+#define O_WINDOWNAME 74
+#define O_WRAPLEN 75
+#define O_WRAPMARGIN 76
+#define O_WRAPSCAN 77
+#define O_WRITEANY 78
+#define O_OPTIONCOUNT 79
diff --git a/contrib/nvi/vi/v_ex.c b/contrib/nvi/vi/v_ex.c
index 359080c656e3..bcb0ea6a5fd5 100644
--- a/contrib/nvi/vi/v_ex.c
+++ b/contrib/nvi/vi/v_ex.c
@@ -226,6 +226,11 @@ v_tagpush(sp, vp)
 	ARGS *ap[2], a;
 	EXCMD cmd;
 
+#ifdef GTAGS
+	if (O_ISSET(sp, O_GTAGSMODE) && vp->m_start.cno == 0)
+		ex_cinit(&cmd, C_RTAG, 0, OOBLNO, 0, 0, ap);
+	else
+#endif
 	ex_cinit(&cmd, C_TAG, 0, OOBLNO, 0, 0, ap);
 	ex_cadd(&cmd, &a, VIP(sp)->keyw, strlen(VIP(sp)->keyw));
 	return (v_exec_ex(sp, vp, &cmd));