Add optional debugging code

Compile *without* -DNDEBUG. The environment variable PIANOBAR_DEBUG
accepts a bitfield which enables (1) network (2) audio (4) UI debug
messages.

# Conflicts:
#	src/main.c
#	src/player.c
#	src/ui.c

Makefile

@@ -27,6 +27,7 @@ endif
 PIANOBAR_DIR:=src
 PIANOBAR_SRC:=\
 		${PIANOBAR_DIR}/main.c \
+		${PIANOBAR_DIR}/debug.c \
 		${PIANOBAR_DIR}/player.c \
 		${PIANOBAR_DIR}/settings.c \
 		${PIANOBAR_DIR}/terminal.c \

src/config.h

@@ -22,3 +22,10 @@
 #define strcasecmp _stricmp
 #endif
 
+#ifndef NDEBUG
+#define HAVE_DEBUGLOG
+#define debug(...) fprintf(stderr, __VA_ARGS__)
+#else
+#define debug(...)
+#endif
+

src/debug.c

@@ -0,0 +1,29 @@
+/*
+Copyright (c) 2008-2018
+	Lars-Dominik Braun <lars@6xq.net>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include "debug.h"
+
+#ifdef HAVE_DEBUGLOG
+unsigned int debug = 0;
+#endif
+

src/debug.h

@@ -0,0 +1,66 @@
+/*
+Copyright (c) 2008-2018
+	Lars-Dominik Braun <lars@6xq.net>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#pragma once
+
+#include "config.h"
+#include <stdbool.h>
+
+#ifdef HAVE_DEBUGLOG
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+/* bitfield */
+typedef enum {
+	DEBUG_NETWORK = 1,
+	DEBUG_AUDIO = 2,
+	DEBUG_UI = 4,
+} debugKind;
+
+extern unsigned int debug;
+
+inline static bool debugEnable () {
+	const char * const debugStr = getenv("PIANOBAR_DEBUG");
+	if (debugStr != NULL) {
+		debug = atoi (debugStr);
+	}
+	return debug;
+}
+
+#ifndef _MSC_VER
+__attribute__((format(printf, 2, 3)))
+#endif
+inline static void debugPrint(debugKind kind, const char * const format, ...) {
+	if (debug & kind) {
+		va_list fmtargs;
+		va_start (fmtargs, format);
+		vfprintf (stderr, format, fmtargs);
+		va_end (fmtargs);
+	}
+}
+#else
+inline static bool debugEnable () {}
+#define debugPrint(...)
+#endif
+

src/main.c

@@ -27,6 +27,7 @@ THE SOFTWARE.
 #include <piano.h>
 
 #include "main.h"
+#include "debug.h"
 #include "console.h"
 #include "hotkey.h"
 #include "ui.h"
@@ -414,6 +415,8 @@ int main(int argc, char **argv)
 {
     static BarApp_t app;
 
+	debugEnable();
+
     memset(&app, 0, sizeof(app));
 
     BarConsoleInit();
@@ -422,6 +425,7 @@ int main(int argc, char **argv)
 
     BarHotKeyInit();
 
+
     /* init some things */
     BarSettingsInit(&app.settings);
     BarSettingsRead(&app.settings);

src/ui.c

@@ -26,6 +26,7 @@ THE SOFTWARE.
 #include "config.h"
 
 #include "ui.h"
+#include "debug.h"
 #include "ui_readline.h"
 #include "console.h"
 #include <assert.h>