From c5cc22a13fe49908f50e099994645a0f9a96c95b Mon Sep 17 00:00:00 2001
From: tg <tg@mirbsd.org>
Date: Fri, 23 Mar 2012 19:38:12 +0000
Subject: [PATCH] efficient debug-to-file output (/tmp racy, but hey)

---
 Makefile |  7 ++++++-
 main.c   | 46 +++++++++++++++++++++++++++++++++++++++++++---
 sh.h     |  9 ++++++++-
 3 files changed, 57 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index 6af99d2..8a54669 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/Makefile,v 1.92 2011/12/31 02:04:17 tg Exp $
+# $MirOS: src/bin/mksh/Makefile,v 1.93 2012/03/23 19:38:11 tg Exp $
 #-
 # Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
 #	Thorsten Glaser <tg@mirbsd.org>
@@ -58,6 +58,11 @@ SRCS+=		printf.c
 CPPFLAGS+=	-DMKSH_PRINTF_BUILTIN
 .endif
 
+DEBUGFILE?=	No
+.if ${DEBUGFILE:L} == "yes"
+CPPFLAGS+=	-DDF=mksh_debugtofile
+.endif
+
 MANLINKS=	[ false pwd sh sleep test true
 BINLINKS=	${MANLINKS} echo domainname kill
 .for _i in ${BINLINKS}
diff --git a/main.c b/main.c
index 3ba27dd..bacd550 100644
--- a/main.c
+++ b/main.c
@@ -34,7 +34,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.206 2012/03/23 18:58:15 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.207 2012/03/23 19:38:12 tg Exp $");
 
 extern char **environ;
 
@@ -1242,7 +1242,13 @@ can_seek(int fd)
 	    SHF_UNBUF : 0);
 }
 
-struct shf shf_iob[3];
+#ifdef DF
+int shl_dbg_fd;
+#define NSHF_IOB 4
+#else
+#define NSHF_IOB 3
+#endif
+struct shf shf_iob[NSHF_IOB];
 
 void
 initio(void)
@@ -1250,8 +1256,22 @@ initio(void)
 	/* force buffer allocation */
 	shf_fdopen(1, SHF_WR, shl_stdout);
 	shf_fdopen(2, SHF_WR, shl_out);
-	/* force buffer allocation */
 	shf_fdopen(2, SHF_WR, shl_spare);
+#ifdef DF
+	if ((shl_dbg_fd = open("/tmp/mksh-dbg.txt",
+	    O_WRONLY | O_APPEND | O_CREAT, 0600)) == -1)
+		errorf("cannot open debug output file");
+	if (shl_dbg_fd < FDBASE) {
+		int nfd;
+
+		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
+		close(shl_dbg_fd);
+		if ((shl_dbg_fd = nfd) == -1)
+			errorf("cannot dup debug output file");
+	}
+	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
+	DF("=== open ===");
+#endif
 	initio_done = true;
 }
 
@@ -1694,3 +1714,23 @@ x_sigwinch(int sig MKSH_A_UNUSED)
 	got_winch = 1;
 }
 #endif
+
+#ifdef DF
+void
+DF(const char *fmt, ...)
+{
+	va_list args;
+	struct timeval tv;
+
+	(void)flock(shl_dbg_fd, LOCK_EX);
+	gettimeofday(&tv, NULL);
+	shf_fprintf(shl_dbg, "[%d.%06d:%d] ", (int)tv.tv_sec, (int)tv.tv_usec,
+	    (int)getpid());
+	va_start(args, fmt);
+	shf_vfprintf(shl_dbg, fmt, args);
+	va_end(args);
+	shf_putc('\n', shl_dbg);
+	shf_flush(shl_dbg);
+	(void)flock(shl_dbg_fd, LOCK_UN);
+}
+#endif
diff --git a/sh.h b/sh.h
index 3767bd0..0f20462 100644
--- a/sh.h
+++ b/sh.h
@@ -152,7 +152,7 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.522 2012/03/03 21:30:57 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.523 2012/03/23 19:38:12 tg Exp $");
 #endif
 #define MKSH_VERSION "R40 2012/03/03"
 
@@ -697,6 +697,9 @@ struct temp {
 #define shl_spare	(&shf_iob[0])	/* for c_read()/c_print() */
 #define shl_stdout	(&shf_iob[1])
 #define shl_out		(&shf_iob[2])
+#ifdef DF
+#define shl_dbg		(&shf_iob[3])	/* for DF() */
+#endif
 EXTERN bool shl_stdout_ok;
 
 /*
@@ -1744,6 +1747,10 @@ struct tbl *ktenter(struct table *, const char *, uint32_t);
 void ktwalk(struct tstate *, struct table *);
 struct tbl *ktnext(struct tstate *);
 struct tbl **ktsort(struct table *);
+#ifdef DF
+void DF(const char *, ...)
+    MKSH_A_FORMAT(__printf__, 1, 2);
+#endif
 /* misc.c */
 void setctypes(const char *, int);
 void initctypes(void);