Add mtags to generate tags for make and mdoc

5 files changed, 161 insertions, 2 deletions

diff --git a/bin/.gitignore b/bin/.gitignore
index d2b46a7f..a52982b3 100644
--- a/bin/.gitignore
+++ b/bin/.gitignore
@@ -16,6 +16,7 @@ hnel
 htagml
 htmltags
 modem
+mtags
 nudge
 open
 order
diff --git a/bin/Makefile b/bin/Makefile
index 13dfb2f2..b133232f 100644
--- a/bin/Makefile
+++ b/bin/Makefile
@@ -29,6 +29,7 @@ BINS += hilex
 BINS += hnel
 BINS += htagml
 BINS += modem
+BINS += mtags
 BINS += nudge
 BINS += order
 BINS += pbd
@@ -132,9 +133,10 @@ html: ${HTMLS}
 
 ${HTMLS}: html.sh scheme hilex htagml htmltags
 
-htmltags: *.[chly]
+htmltags: *.[chly] mtags Makefile
 	rm -f $@
 	for f in *.[chly]; do ctags -aw -f $@ $$f; done
+	./mtags -a -f $@ Makefile
 
 .SUFFIXES: .html
 
diff --git a/bin/README.7 b/bin/README.7
index aded212e..723845e2 100644
--- a/bin/README.7
+++ b/bin/README.7
@@ -1,4 +1,4 @@
-.Dd January 13, 2021
+.Dd January 19, 2021
 .Dt BIN 7
 .Os "Causal Agency"
 .
@@ -44,6 +44,8 @@ PTY input remapper
 tags HTMLizer
 .It Xr modem 1
 fixed baud rate wrapper
+.It Xr mtags 1
+miscellaneous tags
 .It Xr nudge 1
 terminal vibrator
 .It Xr order 1
diff --git a/bin/man1/mtags.1 b/bin/man1/mtags.1
new file mode 100644
index 00000000..bb4b50b4
--- /dev/null
+++ b/bin/man1/mtags.1
@@ -0,0 +1,68 @@
+.Dd January 19, 2021
+.Dt MTAGS 1
+.Os
+.
+.Sh NAME
+.Nm mtags
+.Nd miscellaneous tags
+.
+.Sh SYNOPSIS
+.Nm
+.Op Fl a
+.Op Fl f Ar tagsfile
+.Ar
+.
+.Sh DESCRIPTION
+The
+.Nm
+utility
+makes a
+.Pa tags
+file for
+.Xr ex 1
+from the specified
+.Xr make 1
+and
+.Xr mdoc 7
+sources.
+.
+.Pp
+The arguments are as follows:
+.Bl -tag -width Ds
+.It Fl a
+Append to
+.Pa tags
+file.
+.It Fl f Ar tagsfile
+Place the tag descriptions
+in a file called
+.Ar tagsfile .
+The default behaviour is
+to place them in a file called
+.Pa tags .
+.El
+.
+.Pp
+Files whose names are
+.Pa Makefile
+or end in
+.Pa .mk
+are assumed to be
+.Xr make 1
+files.
+Files whose names end in
+.Pa .[1-9]
+are assumed to be
+.Xr mdoc 7
+files.
+.
+.Sh FILES
+.Bl -tag -width Ds
+.It Pa tags
+default output tags file
+.El
+.
+.Sh SEE ALSO
+.Xr ctags 1 ,
+.Xr ex 1 ,
+.Xr vi 1
diff --git a/bin/mtags.c b/bin/mtags.c
new file mode 100644
index 00000000..3ff72c19
--- /dev/null
+++ b/bin/mtags.c
@@ -0,0 +1,86 @@
+/* Copyright (C) 2021  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <err.h>
+#include <regex.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+	bool append = false;
+	const char *path = "tags";
+	for (int opt; 0 < (opt = getopt(argc, argv, "af:"));) {
+		switch (opt) {
+			break; case 'a': append = true;
+			break; case 'f': path = optarg;
+			break; default:  return EX_USAGE;
+		}
+	}
+
+	FILE *tags = fopen(path, (append ? "a" : "w"));
+	if (!tags) err(EX_CANTCREAT, "%s", path);
+
+	regex_t makeFile, makeLine;
+	regex_t mdocFile, mdocLine;
+	int error = 0
+		|| regcomp(&makeFile, "(^|/)Makefile|[.]mk$", REG_EXTENDED | REG_NOSUB)
+		|| regcomp(
+			&makeLine,
+			"^([.][^$A-Z][^$[:space:]]*|[^.$][^$[:space:]]*):",
+			REG_EXTENDED
+		)
+		|| regcomp(&mdocFile, "[.][1-9]$", REG_EXTENDED | REG_NOSUB)
+		|| regcomp(&mdocLine, "^[.]S[hs] ([^\t\n]+)", REG_EXTENDED);
+	assert(!error);
+
+	size_t cap = 0;
+	char *buf = NULL;
+	for (int i = optind; i < argc; ++i) {
+		const regex_t *regex;
+		if (!regexec(&makeFile, argv[i], 0, NULL, 0)) {
+			regex = &makeLine;
+		} else if (!regexec(&mdocFile, argv[i], 0, NULL, 0)) {
+			regex = &mdocLine;
+		} else {
+			warnx("skipping unknown file type %s", argv[i]);
+			continue;
+		}
+
+		FILE *file = fopen(argv[i], "r");
+		if (!file) err(EX_NOINPUT, "%s", argv[i]);
+
+		while (0 < getline(&buf, &cap, file)) {
+			regmatch_t match[2];
+			if (regexec(regex, buf, 2, match, 0)) continue;
+			int n = fprintf(
+				tags, "%.*s\t%s\t/^%.*s/\n",
+				(int)(match[1].rm_eo - match[1].rm_so), &buf[match[1].rm_so],
+				argv[i],
+				(int)(match[0].rm_eo - match[0].rm_so), &buf[match[0].rm_so]
+			);
+			if (n < 0) err(EX_IOERR, "%s", path);
+		}
+		fclose(file);
+	}
+
+	error = fclose(tags);
+	if (error) err(EX_IOERR, "%s", path);
+}