From dc9523b79494e25195311bff75491791f1d9a4a5 Mon Sep 17 00:00:00 2001
From: jsg <jsg@openbsd.org>
Date: Fri, 8 Aug 2014 12:40:26 +0000
Subject: [PATCH] Add support for using - as shorthand for stdin/stdout in
 tradcpp.

When looking into switching the /usr/bin/cpp wrapper to
tradcpp I came across "| ${CPP} ${CPPFLAGS} -" in usr.bin/which.

gcc documents this behaviour for cpp here:
https://gcc.gnu.org/onlinedocs/cpp/Invocation.html

Versions of the John F. Reiser derived cpp in 32V and CSRG SCCS
accept this usage as well, as does the cpp in PCC.
---
 libexec/tradcpp/files.c  | 2 +-
 libexec/tradcpp/main.c   | 2 +-
 libexec/tradcpp/output.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/libexec/tradcpp/files.c b/libexec/tradcpp/files.c
index f0ee45eee55..ea151b23286 100644
--- a/libexec/tradcpp/files.c
+++ b/libexec/tradcpp/files.c
@@ -400,7 +400,7 @@ file_readabsolute(struct place *place, const char *name)
 
 	assert(place != NULL);
 
-	if (name == NULL) {
+	if ((name == NULL) || !strcmp(name, "-")) {
 		fd = STDIN_FILENO;
 		pf = place_addfile(place, "<standard-input>", false);
 	} else {
diff --git a/libexec/tradcpp/main.c b/libexec/tradcpp/main.c
index 35f9bca1326..eae7f44632d 100644
--- a/libexec/tradcpp/main.c
+++ b/libexec/tradcpp/main.c
@@ -1040,7 +1040,7 @@ main(int argc, char *argv[])
 	init();
 
 	for (i=1; i<argc; i++) {
-		if (argv[i][0] != '-') {
+		if ((argv[i][0] != '-') || !strcmp(argv[i], "-")) {
 			break;
 		}
 		place_setcommandline(&cmdplace, i, 1);
diff --git a/libexec/tradcpp/output.c b/libexec/tradcpp/output.c
index d1d1f2d4d94..5cc7165892c 100644
--- a/libexec/tradcpp/output.c
+++ b/libexec/tradcpp/output.c
@@ -47,7 +47,7 @@ static
 void
 output_open(void)
 {
-	if (mode.output_file == NULL) {
+	if ((mode.output_file == NULL) || !strcmp(mode.output_file, "-")) {
 		outputfd = STDOUT_FILENO;
 	} else {
 		outputfd = open(mode.output_file, O_WRONLY|O_CREAT|O_TRUNC,
-- 
2.20.1