Index: usr.bin/diff/diff.h
===================================================================
--- usr.bin/diff/diff.h
+++ usr.bin/diff/diff.h
@@ -72,6 +72,7 @@
 #define D_IGNOREBLANKS		0x200	/* Ignore white space changes */
 #define D_STRIPCR		0x400	/* Strip trailing cr */
 #define D_SKIPBLANKLINES	0x800	/* Skip blank lines */
+#define D_MATCHLAST		0x1000	/* Display last line matching provided regex */
 
 /*
  * Status values for print_status() and diffreg() return values
@@ -94,11 +95,12 @@
 extern int	diff_format, diff_context, status, ignore_file_case;
 extern int	suppress_common;
 extern int	tabsize, width;
-extern char	*start, *ifdefname, *diffargs, *label[2], *ignore_pats;
+extern char	*start, *ifdefname, *diffargs, *label[2];
+extern char	*ignore_pats, *most_recent_pat;
 extern char	*group_format;
 extern struct	stat stb1, stb2;
 extern struct	excludes *excludes_list;
-extern regex_t	ignore_re;
+extern regex_t	ignore_re, most_recent_re;
 
 char	*splice(char *, char *);
 int	diffreg(char *, char *, int, int);
Index: usr.bin/diff/diff.1
===================================================================
--- usr.bin/diff/diff.1
+++ usr.bin/diff/diff.1
@@ -64,11 +64,13 @@
 .Op Fl -text
 .Op Fl -unified
 .Op Fl I Ar pattern | Fl -ignore-matching-lines Ar pattern
+.Op Fl F Ar pattern | Fl -show-function-line Ar pattern
 .Op Fl L Ar label | Fl -label Ar label
 .Ar file1 file2
 .Nm diff
 .Op Fl aBbdilpTtw
 .Op Fl I Ar pattern | Fl -ignore-matching-lines Ar pattern
+.Op Fl F Ar pattern | Fl -show-function-line Ar pattern
 .Op Fl L Ar label | Fl -label Ar label
 .Op Fl -brief
 .Op Fl -changed-group-format Ar GFMT
@@ -120,6 +122,7 @@
 .Nm diff
 .Op Fl aBbdilpTtw
 .Op Fl I Ar pattern | Fl -ignore-matching-lines Ar pattern
+.Op Fl F Ar pattern | Fl -show-function-line Ar pattern
 .Op Fl L Ar label | Fl -label Ar label
 .Op Fl -brief
 .Op Fl -changed-group-format Ar GFMT
@@ -175,6 +178,7 @@
 .Op Fl -unidirectional-new-file
 .Op Fl -unified
 .Op Fl I Ar pattern | Fl -ignore-matching-lines Ar pattern
+.Op Fl F Ar pattern | Fl -show-function-line Ar pattern
 .Bk -words
 .Op Fl L Ar label | Fl -label Ar label
 .Op Fl S Ar name | Fl -starting-file Ar name
@@ -336,6 +340,10 @@
 Try very hard to produce a diff as small as possible.
 This may consume a lot of processing power and memory when processing
 large files with many changes.
+.It Fl F Ar pattern, Fl -show-function-line Ar pattern
+Like
+.Fl p,
+but display the last line that matches provided pattern.
 .It Fl I Ar pattern Fl -ignore-matching-lines Ar pattern
 Ignores changes, insertions, and deletions whose lines match the
 extended regular expression
Index: usr.bin/diff/diff.c
===================================================================
--- usr.bin/diff/diff.c
+++ usr.bin/diff/diff.c
@@ -41,13 +41,14 @@
 int	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag, Wflag;
 int	 diff_format, diff_context, status, ignore_file_case, suppress_common;
 int	 tabsize = 8, width = 130;
-char	*start, *ifdefname, *diffargs, *label[2], *ignore_pats;
+char	*start, *ifdefname, *diffargs, *label[2];
+char	*ignore_pats, *most_recent_pat;
 char	*group_format = NULL;
 struct stat stb1, stb2;
 struct excludes *excludes_list;
-regex_t	 ignore_re;
+regex_t	 ignore_re, most_recent_re;
 
-#define	OPTIONS	"0123456789aBbC:cdD:efHhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
+#define	OPTIONS	"0123456789aBbC:cdD:efF:HhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
 enum {
 	OPT_TSIZE = CHAR_MAX + 1,
 	OPT_STRIPCR,
@@ -67,6 +68,7 @@
 	{ "minimal",			no_argument,		0,	'd' },
 	{ "ed",				no_argument,		0,	'e' },
 	{ "forward-ed",			no_argument,		0,	'f' },
+	{ "show-function-line",		required_argument,	0,	'F' },
 	{ "speed-large-files",		no_argument,		NULL,	'H' },
 	{ "ignore-blank-lines",		no_argument,		0,	'B' },
 	{ "ignore-matching-lines",	required_argument,	0,	'I' },
@@ -100,6 +102,7 @@
 	{ NULL,				0,			0,	'\0'}
 };
 
+void check_regex(char const *, regex_t *);
 void usage(void) __dead2;
 void conflicting_format(void) __dead2;
 void push_excludes(char *);
@@ -184,6 +187,12 @@
 		case 'B':
 			dflags |= D_SKIPBLANKLINES;
 			break;
+		case 'F':
+			if (dflags & D_PROTOTYPE)
+				conflicting_format();
+			dflags |= D_MATCHLAST;
+			most_recent_pat = xstrdup(optarg);
+			break;
 		case 'I':
 			push_ignore_pats(optarg);
 			break;
@@ -210,6 +219,8 @@
 			diff_format = D_NREVERSE;
 			break;
 		case 'p':
+			if (dflags & D_MATCHLAST)
+				conflicting_format();
 			dflags |= D_PROTOTYPE;
 			break;
 		case 'P':
@@ -327,19 +338,8 @@
 	 */
 	if (argc != 2)
 		usage();
-	if (ignore_pats != NULL) {
-		char buf[BUFSIZ];
-		int error;
-
-		if ((error = regcomp(&ignore_re, ignore_pats,
-				     REG_NEWLINE | REG_EXTENDED)) != 0) {
-			regerror(error, &ignore_re, buf, sizeof(buf));
-			if (*ignore_pats != '\0')
-				errx(2, "%s: %s", ignore_pats, buf);
-			else
-				errx(2, "%s", buf);
-		}
-	}
+	check_regex(ignore_pats, &ignore_re);
+	check_regex(most_recent_pat, &most_recent_re);
 	if (strcmp(argv[0], "-") == 0) {
 		fstat(STDIN_FILENO, &stb1);
 		gotstdin = 1;
@@ -394,6 +394,25 @@
 	exit(status);
 }
 
+void
+check_regex(char const *pattern, regex_t *comp)
+{
+	char buf[BUFSIZ];
+	int error;
+
+	if (pattern == NULL)
+		return;
+
+	error = regcomp(comp, pattern, REG_NEWLINE | REG_EXTENDED);
+	if (error != 0) {
+		regerror(error, comp, buf, sizeof(buf));
+		if (*pattern != '\0')
+			errx(2, "%s: %s", pattern, buf);
+		else
+			errx(2, "%s", buf);
+	}
+}
+
 void
 set_argstr(char **av, char **ave)
 {
@@ -522,18 +541,18 @@
 	(void)fprintf(stderr,
 	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
-	    "            [-I pattern] [-L label] file1 file2\n"
+	    "            [-I pattern] [-F pattern] [-L label] file1 file2\n"
 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
-	    "            -C number file1 file2\n"
+	    "            [-F pattern] -C number file1 file2\n"
 	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
 	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
 	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
-	    "            -U number file1 file2\n"
+	    "            [-F pattern] -U number file1 file2\n"
 	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
 	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
-	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n"
+	    "            [-F pattern] [-S name] [-X file] [-x pattern] dir1 dir2\n"
 	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
             "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
             "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
Index: usr.bin/diff/diffreg.c
===================================================================
--- usr.bin/diff/diffreg.c
+++ usr.bin/diff/diffreg.c
@@ -1402,43 +1402,49 @@
 match_function(const long *f, int pos, FILE *fp)
 {
 	unsigned char buf[FUNCTION_CONTEXT_SIZE];
-	size_t nc;
+	size_t nc, read;
 	int last = lastline;
 	const char *state = NULL;
 
 	lastline = pos;
-	while (pos > last) {
+	for (; pos > last; pos--) {
 		fseek(fp, f[pos - 1], SEEK_SET);
 		nc = f[pos] - f[pos - 1];
 		if (nc >= sizeof(buf))
 			nc = sizeof(buf) - 1;
-		nc = fread(buf, 1, nc, fp);
-		if (nc > 0) {
-			buf[nc] = '\0';
-			buf[strcspn(buf, "\n")] = '\0';
-			if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
-				if (begins_with(buf, "private:")) {
-					if (!state)
-						state = " (private)";
-				} else if (begins_with(buf, "protected:")) {
-					if (!state)
-						state = " (protected)";
-				} else if (begins_with(buf, "public:")) {
-					if (!state)
-						state = " (public)";
-				} else {
-					strlcpy(lastbuf, buf, sizeof lastbuf);
-					if (state)
-						strlcat(lastbuf, state,
-						    sizeof lastbuf);
-					lastmatchline = pos;
-					return lastbuf;
-				}
+		read = fread(buf, 1, nc, fp);
+		if (read < nc)
+			break;
+
+		buf[nc] = '\0';
+		buf[strcspn(buf, "\n")] = '\0';
+		if (most_recent_pat != NULL) {
+			int ret = regexec(&most_recent_re, buf, 0, NULL, 0);
+			if (ret != 0)
+				continue;
+			strlcpy(lastbuf, buf, sizeof(lastbuf));
+			lastmatchline = pos;
+			return (lastbuf);
+		} else if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
+			if (begins_with(buf, "private:")) {
+				if (!state)
+					state = " (private)";
+			} else if (begins_with(buf, "protected:")) {
+				if (!state)
+					state = " (protected)";
+			} else if (begins_with(buf, "public:")) {
+				if (!state)
+					state = " (public)";
+			} else {
+				strlcpy(lastbuf, buf, sizeof(lastbuf));
+				if (state)
+					strlcat(lastbuf, state, sizeof(lastbuf));
+				lastmatchline = pos;
+				return (lastbuf);
 			}
 		}
-		pos--;
 	}
-	return lastmatchline > 0 ? lastbuf : NULL;
+	return (lastmatchline > 0 ? lastbuf : NULL);
 }
 
 /* dump accumulated "context" diff changes */
@@ -1460,7 +1466,7 @@
 	upd = MIN(len[1], context_vec_ptr->d + diff_context);
 
 	printf("***************");
-	if ((flags & D_PROTOTYPE)) {
+	if (flags & (D_PROTOTYPE | D_MATCHLAST)) {
 		f = match_function(ixold, lowa-1, f1);
 		if (f != NULL)
 			printf(" %s", f);
@@ -1567,7 +1573,7 @@
 	printf(" +");
 	uni_range(lowc, upd);
 	printf(" @@");
-	if ((flags & D_PROTOTYPE)) {
+	if ((flags & (D_PROTOTYPE | D_MATCHLAST))) {
 		f = match_function(ixold, lowa-1, f1);
 		if (f != NULL)
 			printf(" %s", f);