[PATCH 01/15] util: add DEBUG_PRINTF, rename error_util.h -> debug_print.h

[David Bremner]

It seemed silly to have two headers that were almost copies.
The new macro is intended for debugging, and probably should not be
left in released code.
---
 command-line-arguments.c             |  2 +-
 lib/notmuch-private.h                |  2 +-
 util/Makefile.local                  |  4 ++--
 util/{error_util.c => debug_print.c} | 16 +++++++++++-----
 util/{error_util.h => debug_print.h} | 22 ++++++++++++++++++----
 util/hex-escape.c                    |  2 +-
 util/util.c                          |  2 +-
 util/xutil.c                         |  2 +-
 8 files changed, 36 insertions(+), 16 deletions(-)
 rename util/{error_util.c => debug_print.c} (81%)
 rename util/{error_util.h => debug_print.h} (75%)

diff --git a/command-line-arguments.c b/command-line-arguments.c
index d64aa85b..90d69453 100644
--- a/command-line-arguments.c
+++ b/command-line-arguments.c
@@ -1,7 +1,7 @@
 #include <assert.h>
 #include <string.h>
 #include <stdio.h>
-#include "error_util.h"
+#include "debug_print.h"
 #include "command-line-arguments.h"
 
 typedef enum {
diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 3764a6a9..499d73d4 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -50,7 +50,7 @@ NOTMUCH_BEGIN_DECLS
 #include "gmime-extra.h"
 
 #include "xutil.h"
-#include "error_util.h"
+#include "debug_print.h"
 #include "string-util.h"
 #include "crypto.h"
 
diff --git a/util/Makefile.local b/util/Makefile.local
index ba03230e..ccf1bd79 100644
--- a/util/Makefile.local
+++ b/util/Makefile.local
@@ -3,9 +3,9 @@
 dir := util
 extra_cflags += -I$(srcdir)/$(dir)
 
-libnotmuch_util_c_srcs := $(dir)/xutil.c $(dir)/error_util.c $(dir)/hex-escape.c \
+libnotmuch_util_c_srcs := $(dir)/xutil.c $(dir)/hex-escape.c \
 		  $(dir)/string-util.c $(dir)/talloc-extra.c $(dir)/zlib-extra.c \
-		$(dir)/util.c $(dir)/gmime-extra.c $(dir)/crypto.c
+		$(dir)/util.c $(dir)/gmime-extra.c $(dir)/crypto.c $(dir)/debug_print.c
 
 libnotmuch_util_modules := $(libnotmuch_util_c_srcs:.c=.o)
 
diff --git a/util/error_util.c b/util/debug_print.c
similarity index 81%
rename from util/error_util.c
rename to util/debug_print.c
index e64162c7..8b4bc73d 100644
--- a/util/error_util.c
+++ b/util/debug_print.c
@@ -1,6 +1,7 @@
 /* error_util.c - internal error utilities for notmuch.
  *
  * Copyright © 2009 Carl Worth
+ * Copyright © 2018 David Bremner
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,11 +19,17 @@
  * Author: Carl Worth <cworth at cworth.org>
  */
 
-#include <stdlib.h>
-#include <stdarg.h>
-#include <stdio.h>
+#include "debug_print.h"
 
-#include "error_util.h"
+void
+_debug_printf (const char *format, ...)
+{
+    va_list va_args;
+
+    va_start (va_args, format);
+    vfprintf (stderr, format, va_args);
+    va_end (va_args);
+}
 
 void
 _internal_error (const char *format, ...)
@@ -37,4 +44,3 @@ _internal_error (const char *format, ...)
     va_end (va_args);
     exit (1);
 }
-
diff --git a/util/error_util.h b/util/debug_print.h
similarity index 75%
rename from util/error_util.h
rename to util/debug_print.h
index 4bb338a2..4a096945 100644
--- a/util/error_util.h
+++ b/util/debug_print.h
@@ -1,6 +1,7 @@
-/* error_util.h - Provide the INTERNAL_ERROR macro
+/* debug_print.h - Provide the INTERNAL_ERROR and DEBUG_PRINTF macros
  *
  * Copyright © 2009 Carl Worth
+ * Copyright © 2018 David Bremner
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,13 +19,26 @@
  * Author: Carl Worth <cworth at cworth.org>
  */
 
-#ifndef ERROR_UTIL_H
-#define ERROR_UTIL_H
+#ifndef DEBUG_PRINT_H
+#define DEBUG_PRINT_H
 
 #include <talloc.h>
-
 #include "function-attributes.h"
 
+void
+_debug_printf (const char *format, ...) PRINTF_ATTRIBUTE (1, 2);
+
+/*
+ * Provide a quick way to silence debugging output.
+ */
+
+#ifdef DEBUG_PRINT
+#define DEBUG_PRINTF(format, ...) _debug_printf(format " (%s).\n",	\
+						##__VA_ARGS__, __location__)
+#else
+#define DEBUG_PRINTF(format, ...) /* ignored */
+#endif
+
 /* There's no point in continuing when we've detected that we've done
  * something wrong internally (as opposed to the user passing in a
  * bogus value).
diff --git a/util/hex-escape.c b/util/hex-escape.c
index 8883ff90..ff20c702 100644
--- a/util/hex-escape.c
+++ b/util/hex-escape.c
@@ -22,7 +22,7 @@
 #include <string.h>
 #include <talloc.h>
 #include <ctype.h>
-#include "error_util.h"
+#include "debug_print.h"
 #include "hex-escape.h"
 
 static const char *output_charset =
diff --git a/util/util.c b/util/util.c
index 06659b35..75df0ead 100644
--- a/util/util.c
+++ b/util/util.c
@@ -1,5 +1,5 @@
 #include "util.h"
-#include "error_util.h"
+#include "debug_print.h"
 #include <string.h>
 #include <errno.h>
 
diff --git a/util/xutil.c b/util/xutil.c
index f211eaaa..11042c9e 100644
--- a/util/xutil.c
+++ b/util/xutil.c
@@ -22,7 +22,7 @@
 #include <string.h>
 
 #include "xutil.h"
-#include "error_util.h"
+#include "debug_print.h"
 
 void *
 xcalloc (size_t nmemb, size_t size)
-- 
2.18.0