system(3) call remove for updating (ctags -u)

done by changing the logic behind updating, by parsing and preloading the tags
file at startup.

"looks good" deraadt@

4 files changed, 92 insertions, 31 deletions

diff --git a/usr.bin/ctags/ctags.1 b/usr.bin/ctags/ctags.1
index 39e8d577f1b..a9961586024 100644
--- a/usr.bin/ctags/ctags.1
+++ b/usr.bin/ctags/ctags.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ctags.1,v 1.28 2015/03/13 19:58:41 jmc Exp $
+.\"	$OpenBSD: ctags.1,v 1.29 2015/08/22 04:23:07 semarie Exp $
 .\"	$NetBSD: ctags.1,v 1.4 1995/03/26 20:14:04 glass Exp $
 .\"
 .\" Copyright (c) 1987, 1990, 1993
@@ -30,7 +30,7 @@
 .\"
 .\"     @(#)ctags.1	8.1 (Berkeley) 6/6/93
 .\"
-.Dd $Mdocdate: March 13 2015 $
+.Dd $Mdocdate: August 22 2015 $
 .Dt CTAGS 1
 .Os
 .Sh NAME
@@ -89,12 +89,8 @@ The default behaviour is to place them in a file called
 Update the specified files in the
 .Ar tags
 file, that is, all
-references to them are deleted, and the new values are appended to the
+references to them are regenerated, keeping only the others values in the
 file.
-(Beware: this option is implemented in a way which is rather
-slow; it is usually faster to simply rebuild the
-.Ar tags
-file.)
 .It Fl v
 An index of the form expected by vgrind
 is produced on the standard output.
diff --git a/usr.bin/ctags/ctags.c b/usr.bin/ctags/ctags.c
index 453708d8167..17473055871 100644
--- a/usr.bin/ctags/ctags.c
+++ b/usr.bin/ctags/ctags.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ctags.c,v 1.15 2015/02/08 23:40:34 deraadt Exp $	*/
+/*	$OpenBSD: ctags.c,v 1.16 2015/08/22 04:23:07 semarie Exp $	*/
 /*	$NetBSD: ctags.c,v 1.4 1995/09/02 05:57:23 jtc Exp $	*/
 
 /*
@@ -65,6 +65,7 @@ char	lbuf[LINE_MAX];
 
 void	init(void);
 void	find_entries(char *);
+void	preload_entries(char *, int, char *[]);
 
 int
 main(int argc, char *argv[])
@@ -75,7 +76,6 @@ main(int argc, char *argv[])
 	int	exit_val;			/* exit value */
 	int	step;				/* step through args */
 	int	ch;				/* getopts char */
-	char	*cmd;
 
 	aflag = uflag = NO;
 	while ((ch = getopt(argc, argv, "BFadf:tuwvx")) != -1)
@@ -122,6 +122,8 @@ usage:		(void)fprintf(stderr,
 	}
 
 	init();
+	if (uflag && !vflag && !xflag)
+		preload_entries(outfile, argc, argv);
 
 	for (exit_val = step = 0; step < argc; ++step)
 		if (!(inf = fopen(argv[step], "r"))) {
@@ -138,30 +140,10 @@ usage:		(void)fprintf(stderr,
 		if (xflag)
 			put_entries(head);
 		else {
-			if (uflag) {
-				for (step = 0; step < argc; step++) {
-					if (asprintf(&cmd,
-					    "mv %s OTAGS; fgrep -v '\t%s\t' OTAGS >%s; rm OTAGS",
-					    outfile, argv[step], outfile) == -1)
-						err(1, "out of space");
-					system(cmd);
-					free(cmd);
-					cmd = NULL;
-				}
-				aflag = 1;
-			}
 			if (!(outf = fopen(outfile, aflag ? "a" : "w")))
 				err(exit_val, "%s", outfile);
 			put_entries(head);
 			(void)fclose(outf);
-			if (uflag) {
-				if (asprintf(&cmd, "sort -o %s %s",
-				    outfile, outfile) == -1)
-						err(1, "out of space");
-				system(cmd);
-				free(cmd);
-				cmd = NULL;
-			}
 		}
 	}
 	exit(exit_val);
@@ -253,3 +235,79 @@ find_entries(char *file)
 	}
 /* C */	c_entries();
 }
+
+void
+preload_entries(char *tagsfile, int argc, char *argv[])
+{
+	FILE	*fp;
+	char	 line[LINE_MAX];
+	char	*entry = NULL;
+	char	*file = NULL;
+	char	*pattern = NULL;
+	char	*eol;
+	int	 i;
+
+	in_preload = YES;
+
+	if ((fp = fopen(tagsfile, "r")) == NULL)
+		err(1, "preload_entries: %s", tagsfile);
+
+	while (1) {
+next:
+		if (fgets(line, sizeof(line), fp) == NULL)
+			break;
+
+		if ((eol = strchr(line, '\n')) == NULL)
+			errx(1, "preload_entries: line too long");
+		*eol = '\0';
+
+		/* extract entry */
+		entry = line;
+		if ((file = strchr(line, '\t')) == NULL)
+			errx(1, "preload_entries: couldn't parse entry: %s",
+			    tagsfile);
+		*file = '\0';
+
+		/* extract file */
+		file++;
+		if ((pattern = strchr(file, '\t')) == NULL)
+			errx(1, "preload_entries: couldn't parse filename: %s",
+			    tagsfile);
+		*pattern = '\0';
+
+		/* skip this file ? */
+		for(i = 0; i < argc; i++)
+			if (strcmp(file, argv[i]) == 0)
+				goto next;
+
+		/* rest of string is pattern */
+		pattern++;
+
+		/* grab searchar, and don't keep it around the pattern */
+		if ((pattern[0] == '/' || pattern[0] == '?')
+		    && pattern[1] == '^') {
+
+			i = strlen(pattern);
+			if (pattern[i-1] == pattern[0])
+				/* remove searchar at end */
+				pattern[i-1] = '\0';
+			else
+				errx(1, "preload_entries: couldn't parse "
+				    "pattern: %s", tagsfile);
+
+			/* remove searchar at begin */
+			pattern += 2;
+		}
+
+		/* add entry */
+		if ((curfile = strdup(file)) == NULL)
+			err(1, "preload_entries: strdup");
+		(void)strlcpy(lbuf, pattern, sizeof(lbuf));
+		pfnote(entry, 0);
+	}
+	if (ferror(fp))
+		err(1, "preload_entries: fgets");
+
+	(void)fclose(fp);
+	in_preload = NO;
+}
diff --git a/usr.bin/ctags/ctags.h b/usr.bin/ctags/ctags.h
index b232027a51c..0a76c2429b7 100644
--- a/usr.bin/ctags/ctags.h
+++ b/usr.bin/ctags/ctags.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ctags.h,v 1.8 2014/12/10 19:44:21 tobias Exp $	*/
+/*	$OpenBSD: ctags.h,v 1.9 2015/08/22 04:23:07 semarie Exp $	*/
 /*	$NetBSD: ctags.h,v 1.3 1995/03/26 20:14:07 glass Exp $	*/
 
 /*
@@ -56,6 +56,7 @@ typedef struct nd_st {			/* sorting structure */
 		*pat;			/* search pattern */
 	int	lno;			/* for -x option */
 	bool	been_warned;		/* set if noticed dup */
+	bool	dynfile;		/* set if file will need freed */
 } NODE;
 
 extern char	*curfile;		/* current input file name */
@@ -72,6 +73,7 @@ extern bool	_wht[], _itk[], _btk[];
 extern char	lbuf[LINE_MAX];
 extern char    *lbp;
 extern char	searchar;		/* ex search character */
+extern bool	in_preload;
 
 extern int	cicmp(char *);
 extern void	get_line(void);
diff --git a/usr.bin/ctags/tree.c b/usr.bin/ctags/tree.c
index 98ac352b2f5..e419edabdfa 100644
--- a/usr.bin/ctags/tree.c
+++ b/usr.bin/ctags/tree.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tree.c,v 1.11 2015/08/20 22:32:41 deraadt Exp $	*/
+/*	$OpenBSD: tree.c,v 1.12 2015/08/22 04:23:07 semarie Exp $	*/
 /*	$NetBSD: tree.c,v 1.4 1995/03/26 20:14:11 glass Exp $	*/
 
 /*
@@ -39,6 +39,8 @@
 
 #include "ctags.h"
 
+bool	in_preload = NO;
+
 static void	add_node(NODE *, NODE *);
 static void	free_tree(NODE *);
 
@@ -79,6 +81,7 @@ pfnote(char *name, int ln)
 	np->lno = ln;
 	np->left = np->right = 0;
 	np->been_warned = NO;
+	np->dynfile = in_preload;
 	if (!(np->pat = strdup(lbuf)))
 		err(1, NULL);
 	if (!head)
@@ -128,6 +131,8 @@ free_tree(NODE *node)
 
 		free(node->entry);
 		free(node->pat);
+		if (node->dynfile == YES)
+			free(node->file);
 		free(node);
 	}
 }