Implement -p option.

"works here" millert@ ok miod@ deraadt@

3 files changed, 76 insertions, 17 deletions

diff --git a/usr.bin/diff/diff.c b/usr.bin/diff/diff.c
index 5fa299fa73f..7ad00106cae 100644
--- a/usr.bin/diff/diff.c
+++ b/usr.bin/diff/diff.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: diff.c,v 1.43 2003/10/07 23:37:27 millert Exp $	*/
+/*	$OpenBSD: diff.c,v 1.44 2004/01/07 17:18:32 otto Exp $	*/
 
 /*
  * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -21,7 +21,7 @@
  */
 
 #ifndef lint
-static const char rcsid[] = "$OpenBSD: diff.c,v 1.43 2003/10/07 23:37:27 millert Exp $";
+static const char rcsid[] = "$OpenBSD: diff.c,v 1.44 2004/01/07 17:18:32 otto Exp $";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -40,14 +40,14 @@ static const char rcsid[] = "$OpenBSD: diff.c,v 1.43 2003/10/07 23:37:27 millert
 
 #include "diff.h"
 
-int	 aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, rflag;
+int	 aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, pflag, rflag;
 int	 sflag, tflag, Tflag, wflag;
 int	 format, context, status;
 char	*start, *ifdefname, *diffargs, *label;
 struct stat stb1, stb2;
 struct excludes *excludes_list;
 
-#define	OPTIONS	"0123456789abC:cdD:efhiL:lnNPqrS:sTtU:uwX:x:"
+#define	OPTIONS	"0123456789abC:cdD:efhiL:lnNPpqrS:sTtU:uwX:x:"
 static struct option longopts[] = {
 	{ "text",			no_argument,		0,	'a' },
 	{ "ignore-space-change",	no_argument,		0,	'b' },
@@ -62,6 +62,7 @@ static struct option longopts[] = {
 	{ "new-file",			no_argument,		0,	'N' },
 	{ "rcs",			no_argument,		0,	'n' },
 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
+	{ "show-c-function",		no_argument,		0,	'p' },
 	{ "brief",			no_argument,		0,	'q' },
 	{ "recursive",			no_argument,		0,	'r' },
 	{ "report-identical-files",	no_argument,		0,	's' },
@@ -154,6 +155,9 @@ main(int argc, char **argv)
 		case 'n':
 			format = D_NREVERSE;
 			break;
+		case 'p':
+			pflag = 1;
+			break;
 		case 'P':
 			Pflag = 1;
 			break;
@@ -388,11 +392,11 @@ __dead void
 usage(void)
 {
 	(void)fprintf(stderr,
-	    "usage: diff [-abdilqtTw] [-c | -e | -f | -n | -u] [-L label] file1 file2\n"
-	    "       diff [-abdilqtTw] [-L label] -C number file1 file2\n"
+	    "usage: diff [-abdilpqtTw] [-c | -e | -f | -n | -u] [-L label] file1 file2\n"
+	    "       diff [-abdilpqtTw] [-L label] -C number file1 file2\n"
 	    "       diff [-abdilqtw] -D string file1 file2\n"
-	    "       diff [-abdilqtTw] [-L label] -U number file1 file2\n"
-	    "       diff [-abdilNPqtTw] [-c | -e | -f | -n | -u ] [-L label] [-r] [-s]\n"
+	    "       diff [-abdilpqtTw] [-L label] -U number file1 file2\n"
+	    "       diff [-abdilNPpqtTw] [-c | -e | -f | -n | -u ] [-L label] [-r] [-s]\n"
 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n");
 
 	exit(2);
diff --git a/usr.bin/diff/diff.h b/usr.bin/diff/diff.h
index 538d67df19d..7f658699fa3 100644
--- a/usr.bin/diff/diff.h
+++ b/usr.bin/diff/diff.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: diff.h,v 1.25 2003/11/09 20:13:57 otto Exp $	*/
+/*	$OpenBSD: diff.h,v 1.26 2004/01/07 17:18:32 otto Exp $	*/
 
 /*-
  * Copyright (c) 1991, 1993
@@ -68,8 +68,8 @@ struct excludes {
 	struct excludes *next;
 };
 
-extern int	aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, rflag, sflag,
-		tflag, Tflag, wflag;
+extern int	aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, pflag, rflag,
+		sflag, tflag, Tflag, wflag;
 extern int	format, context, status;
 extern char	*start, *ifdefname, *diffargs, *label;
 extern struct	stat stb1, stb2;
diff --git a/usr.bin/diff/diffreg.c b/usr.bin/diff/diffreg.c
index 74645a3c794..e2e60305f44 100644
--- a/usr.bin/diff/diffreg.c
+++ b/usr.bin/diff/diffreg.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: diffreg.c,v 1.54 2003/11/22 18:02:44 millert Exp $	*/
+/*	$OpenBSD: diffreg.c,v 1.55 2004/01/07 17:18:32 otto Exp $	*/
 
 /*
  * Copyright (C) Caldera International Inc.  2001-2002.
@@ -65,7 +65,7 @@
  */
 
 #ifndef lint
-static const char rcsid[] = "$OpenBSD: diffreg.c,v 1.54 2003/11/22 18:02:44 millert Exp $";
+static const char rcsid[] = "$OpenBSD: diffreg.c,v 1.55 2004/01/07 17:18:32 otto Exp $";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -195,6 +195,11 @@ static struct context_vec *context_vec_start;
 static struct context_vec *context_vec_end;
 static struct context_vec *context_vec_ptr;
 
+#define FUNCTION_CONTEXT_SIZE	41
+static char lastbuf[FUNCTION_CONTEXT_SIZE];
+static int lastline;
+static int lastmatchline;
+
 static FILE *opentemp(const char *);
 static void output(char *, FILE *, char *, FILE *);
 static void check(char *, FILE *, char *, FILE *);
@@ -220,6 +225,7 @@ static int  readhash(FILE *);
 static int  files_differ(FILE *, FILE *, int);
 static __inline int min(int, int);
 static __inline int max(int, int);
+static char *match_function(const long *, int, FILE *);
 
 
 /*
@@ -292,6 +298,8 @@ diffreg(char *ofile1, char *ofile2, int flags)
 	pid_t pid = -1;
 
 	anychange = 0;
+	lastline = 0;
+	lastmatchline = 0;
 	context_vec_ptr = context_vec_start - 1;
 	chrtran = (iflag ? cup2low : clow2low);
 	if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
@@ -1241,6 +1249,37 @@ static __inline int max(int a, int b)
 	return (a > b ? a : b);
 }
 
+static char *
+match_function(const long *f, int pos, FILE *file)
+{
+	char buf[FUNCTION_CONTEXT_SIZE];
+	size_t nc;
+	int last = lastline;
+	char *p;
+
+	lastline = pos;
+	while (pos > last) {
+		fseek(file, f[pos - 1], SEEK_SET);
+		nc = f[pos] - f[pos - 1];
+		if (nc >= sizeof(buf))
+			nc = sizeof(buf) - 1;
+		nc = fread(buf, 1, nc, file);
+		if (nc > 0) {
+			buf[nc] = '\0';
+			p = strchr(buf, '\n');
+			if (p != NULL)
+				*p = '\0';
+			if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
+				strlcpy(lastbuf, buf, sizeof lastbuf);
+				lastmatchline = pos;
+				return lastbuf;
+			}
+		}
+		pos--;
+	}
+	return lastmatchline > 0 ? lastbuf : NULL;
+}
+
 /* dump accumulated "context" diff changes */
 static void
 dump_context_vec(FILE *f1, FILE *f2)
@@ -1248,7 +1287,7 @@ dump_context_vec(FILE *f1, FILE *f2)
 	struct context_vec *cvp = context_vec_start;
 	int lowa, upb, lowc, upd, do_output;
 	int a, b, c, d;
-	char ch;
+	char ch, *f;
 
 	if (context_vec_start > context_vec_ptr)
 		return;
@@ -1259,7 +1298,15 @@ dump_context_vec(FILE *f1, FILE *f2)
 	lowc = max(1, cvp->c - context);
 	upd = min(len[1], context_vec_ptr->d + context);
 
-	printf("***************\n*** ");
+	printf("***************");
+	if (pflag) {
+		f = match_function(ixold, lowa-1, f1);
+		if (f != NULL) {
+			putchar(' ');
+			fputs(f, stdout);
+		}
+	}
+	printf("\n*** ");
 	range(lowa, upb, ",");
 	printf(" ****\n");
 
@@ -1345,7 +1392,7 @@ dump_unified_vec(FILE *f1, FILE *f2)
 	struct context_vec *cvp = context_vec_start;
 	int lowa, upb, lowc, upd;
 	int a, b, c, d;
-	char ch;
+	char ch, *f;
 
 	if (context_vec_start > context_vec_ptr)
 		return;
@@ -1360,7 +1407,15 @@ dump_unified_vec(FILE *f1, FILE *f2)
 	uni_range(lowa, upb);
 	fputs(" +", stdout);
 	uni_range(lowc, upd);
-	fputs(" @@\n", stdout);
+	fputs(" @@", stdout);
+	if (pflag) {
+		f = match_function(ixold, lowa-1, f1);
+		if (f != NULL) {
+			putchar(' ');
+			fputs(f, stdout);
+		}
+	}
+	putchar('\n');
 
 	/*
 	 * Output changes in "unified" diff format--the old and new lines