From 32fcfde86b3d57305c29b545aa084d28c7c76fe9 Mon Sep 17 00:00:00 2001
From: Bastien Nocera <hadess@hadess.net>
Date: Wed, 23 May 2018 17:48:55 +0200
Subject: [PATCH] lib: Use GLib and libusb directly for debug output

Use GLib internally to output debug information, and tell about
libusb's LIBUSB_DEBUG envvar for libusb debug.

fp_set_debug() is now a no-op.

https://bugs.freedesktop.org/show_bug.cgi?id=106552
---
 libfprint/aeslib.c             |   3 +-
 libfprint/assembling.c         |   3 +-
 libfprint/async.c              |   4 +-
 libfprint/core.c               | 106 ++++++---------------------------
 libfprint/drivers/aes1610.c    |   3 +-
 libfprint/drivers/aes1660.c    |   3 +-
 libfprint/drivers/aes2501.c    |   3 +-
 libfprint/drivers/aes2550.c    |   3 +-
 libfprint/drivers/aes2660.c    |   4 +-
 libfprint/drivers/aes3500.c    |   3 +-
 libfprint/drivers/aes3k.c      |   3 +-
 libfprint/drivers/aes4000.c    |   3 +-
 libfprint/drivers/aesx660.c    |   3 +-
 libfprint/drivers/elan.c       |   3 +-
 libfprint/drivers/etes603.c    |   6 +-
 libfprint/drivers/fdu2000.c    |   7 ++-
 libfprint/drivers/upeksonly.c  |   4 +-
 libfprint/drivers/upektc.c     |   3 +-
 libfprint/drivers/upektc_img.c |   3 +-
 libfprint/drivers/upekts.c     |   4 +-
 libfprint/drivers/uru4000.c    |   4 +-
 libfprint/drivers/vcom5s.c     |   4 +-
 libfprint/drivers/vfs0050.c    |   3 +-
 libfprint/drivers/vfs101.c     |   8 +--
 libfprint/drivers/vfs301.c     |   4 +-
 libfprint/drv.c                |   4 +-
 libfprint/fp_internal.h        |  31 ++++------
 libfprint/poll.c               |   4 +-
 libfprint/sync.c               |   4 +-
 meson.build                    |   1 +
 30 files changed, 90 insertions(+), 151 deletions(-)

diff --git a/libfprint/aeslib.c b/libfprint/aeslib.c
index 978454d..61811ad 100644
--- a/libfprint/aeslib.c
+++ b/libfprint/aeslib.c
@@ -19,13 +19,14 @@
 
 #define FP_COMPONENT "aeslib"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
 #include <libusb.h>
 #include <glib.h>
 
-#include "fp_internal.h"
 #include "assembling.h"
 #include "aeslib.h"
 
diff --git a/libfprint/assembling.c b/libfprint/assembling.c
index d34cf37..2c4ccc6 100644
--- a/libfprint/assembling.c
+++ b/libfprint/assembling.c
@@ -21,13 +21,14 @@
 
 #define FP_COMPONENT "assembling"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
 #include <libusb.h>
 #include <glib.h>
 
-#include "fp_internal.h"
 #include "assembling.h"
 
 static unsigned int calc_error(struct fpi_frame_asmbl_ctx *ctx,
diff --git a/libfprint/async.c b/libfprint/async.c
index 6718bac..f469a36 100644
--- a/libfprint/async.c
+++ b/libfprint/async.c
@@ -19,12 +19,12 @@
 
 #define FP_COMPONENT "async"
 
+#include "fp_internal.h"
+
 #include <config.h>
 #include <errno.h>
 #include <glib.h>
 
-#include "fp_internal.h"
-
 /* Drivers call this when device initialisation has completed */
 void fpi_drvcb_open_complete(struct fp_dev *dev, int status)
 {
diff --git a/libfprint/core.c b/libfprint/core.c
index e01c16c..06fb24a 100644
--- a/libfprint/core.c
+++ b/libfprint/core.c
@@ -27,9 +27,6 @@
 
 #include "fp_internal.h"
 
-static int log_level = 0;
-static int log_level_fixed = 0;
-
 libusb_context *fpi_usb_ctx = NULL;
 GSList *opened_devices = NULL;
 
@@ -116,52 +113,6 @@ GSList *opened_devices = NULL;
 
 static GSList *registered_drivers = NULL;
 
-void fpi_log(enum fpi_log_level level, const char *component,
-	const char *function, const char *format, ...)
-{
-	va_list args;
-	FILE *stream = stdout;
-	const char *prefix;
-
-	if (!log_level)
-		return;
-	if (level == FPRINT_LOG_LEVEL_WARNING && log_level < 2)
-		return;
-	if (level == FPRINT_LOG_LEVEL_INFO && log_level < 3)
-		return;
-
-	switch (level) {
-	case FPRINT_LOG_LEVEL_INFO:
-		prefix = "info";
-		break;
-	case FPRINT_LOG_LEVEL_WARNING:
-		stream = stderr;
-		prefix = "warning";
-		break;
-	case FPRINT_LOG_LEVEL_ERROR:
-		stream = stderr;
-		prefix = "error";
-		break;
-	case FPRINT_LOG_LEVEL_DEBUG:
-		stream = stderr;
-		prefix = "debug";
-		break;
-	default:
-		stream = stderr;
-		prefix = "unknown";
-		break;
-	}
-
-	fprintf(stream, "%s:%s [%s] ", component ? component : "fp", prefix,
-		function);
-
-	va_start (args, format);
-	vfprintf(stream, format, args);
-	va_end (args);
-
-	fprintf(stream, "\n");
-}
-
 static void register_driver(struct fp_driver *drv)
 {
 	if (drv->id == 0) {
@@ -787,38 +738,11 @@ API_EXPORTED int fp_dev_get_img_height(struct fp_dev *dev)
  * fp_set_debug:
  * @level: the verbosity level
  *
- * Set message verbosity.
- *  - Level 0: no messages ever printed by the library (default)
- *  - Level 1: error messages are printed to stderr
- *  - Level 2: warning and error messages are printed to stderr
- *  - Level 3: informational messages are printed to stdout, warning and error
- *    messages are printed to stderr
- *
- * The default level is 0, which means no messages are ever printed. If you
- * choose to increase the message verbosity level, ensure that your
- * application does not close the stdout/stderr file descriptors.
- *
- * You are advised to set level 3. libfprint is conservative with its message
- * logging and most of the time, will only log messages that explain error
- * conditions and other oddities. This will help you debug your software.
- *
- * If the LIBFPRINT_DEBUG environment variable was set when libfprint was
- * initialized, this function does nothing: the message verbosity is fixed
- * to the value in the environment variable.
- *
- * If libfprint was compiled without any message logging, this function does
- * nothing: you'll never get any messages.
- *
- * If libfprint was compiled with verbose debug message logging, this function
- * does nothing: you'll always get messages from all levels.
+ * This call does nothing, see fp_init() for details.
  */
 API_EXPORTED void fp_set_debug(int level)
 {
-	if (log_level_fixed)
-		return;
-
-	log_level = level;
-	libusb_set_debug(fpi_usb_ctx, level);
+	/* Nothing */
 }
 
 /**
@@ -827,11 +751,27 @@ API_EXPORTED void fp_set_debug(int level)
  * Initialise libfprint. This function must be called before you attempt to
  * use the library in any way.
  *
+ * To enable debug output of libfprint specifically, use GLib's `G_MESSAGES_DEBUG`
+ * environment variable as explained in [Running and debugging GLib Applications](https://developer.gnome.org/glib/stable/glib-running.html#G_MESSAGES_DEBUG).
+ *
+ * The log domains used in libfprint are either `libfprint` or `libfprint-FP_COMPONENT`
+ * where `FP_COMPONENT` is defined in the source code for each driver, or component
+ * of the library. Starting with `all` and trimming down is advised.
+ *
+ * To enable debugging of libusb, for USB-based fingerprint reader drivers, use
+ * libusb's `LIBUSB_DEBUG` environment variable as explained in the
+ * [libusb-1.0 API Reference](http://libusb.sourceforge.net/api-1.0/#msglog).
+ *
+ * Example:
+ *
+ * ```
+ * LIBUSB_DEBUG=4 G_MESSAGES_DEBUG=all my-libfprint-application
+ * ```
+ *
  * Returns: 0 on success, non-zero on error.
  */
 API_EXPORTED int fp_init(void)
 {
-	char *dbg = getenv("LIBFPRINT_DEBUG");
 	int r;
 	G_DEBUG_HERE();
 
@@ -839,14 +779,6 @@ API_EXPORTED int fp_init(void)
 	if (r < 0)
 		return r;
 
-	if (dbg) {
-		log_level = atoi(dbg);
-		if (log_level) {
-			log_level_fixed = 1;
-			libusb_set_debug(fpi_usb_ctx, log_level);
-		}
-	}
-
 	register_drivers();
 	fpi_poll_init();
 	return 0;
diff --git a/libfprint/drivers/aes1610.c b/libfprint/drivers/aes1610.c
index 40797db..b47396b 100644
--- a/libfprint/drivers/aes1610.c
+++ b/libfprint/drivers/aes1610.c
@@ -25,6 +25,8 @@
 
 #define FP_COMPONENT "aes1610"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
@@ -32,7 +34,6 @@
 
 #include <assembling.h>
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "driver_ids.h"
 
diff --git a/libfprint/drivers/aes1660.c b/libfprint/drivers/aes1660.c
index 32bea4e..ad28b06 100644
--- a/libfprint/drivers/aes1660.c
+++ b/libfprint/drivers/aes1660.c
@@ -19,6 +19,8 @@
 
 #define FP_COMPONENT "aes1660"
 
+#include "fp_internal.h"
+
 #include <stdio.h>
 
 #include <errno.h>
@@ -26,7 +28,6 @@
 
 #include <libusb.h>
 
-#include <fp_internal.h>
 
 #include <assembling.h>
 #include <aeslib.h>
diff --git a/libfprint/drivers/aes2501.c b/libfprint/drivers/aes2501.c
index a78a93d..c1bbc98 100644
--- a/libfprint/drivers/aes2501.c
+++ b/libfprint/drivers/aes2501.c
@@ -23,6 +23,8 @@
 
 #define FP_COMPONENT "aes2501"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
@@ -30,7 +32,6 @@
 
 #include <assembling.h>
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "aes2501.h"
 #include "driver_ids.h"
diff --git a/libfprint/drivers/aes2550.c b/libfprint/drivers/aes2550.c
index bc8ffc1..0516bbc 100644
--- a/libfprint/drivers/aes2550.c
+++ b/libfprint/drivers/aes2550.c
@@ -23,6 +23,8 @@
 
 #define FP_COMPONENT "aes2550"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
@@ -30,7 +32,6 @@
 
 #include <assembling.h>
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "aes2550.h"
 #include "driver_ids.h"
diff --git a/libfprint/drivers/aes2660.c b/libfprint/drivers/aes2660.c
index efe9670..bfc457d 100644
--- a/libfprint/drivers/aes2660.c
+++ b/libfprint/drivers/aes2660.c
@@ -19,6 +19,8 @@
 
 #define FP_COMPONENT "aes2660"
 
+#include "fp_internal.h"
+
 #include <stdio.h>
 
 #include <errno.h>
@@ -26,8 +28,6 @@
 
 #include <libusb.h>
 
-#include <fp_internal.h>
-
 #include <assembling.h>
 #include <aeslib.h>
 
diff --git a/libfprint/drivers/aes3500.c b/libfprint/drivers/aes3500.c
index f229a1a..4428670 100644
--- a/libfprint/drivers/aes3500.c
+++ b/libfprint/drivers/aes3500.c
@@ -29,13 +29,14 @@
 
 #define FP_COMPONENT "aes3500"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 
 #include <glib.h>
 #include <libusb.h>
 
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "aes3k.h"
 #include "driver_ids.h"
diff --git a/libfprint/drivers/aes3k.c b/libfprint/drivers/aes3k.c
index ba96901..f50d2b4 100644
--- a/libfprint/drivers/aes3k.c
+++ b/libfprint/drivers/aes3k.c
@@ -36,13 +36,14 @@
 
 #define FP_COMPONENT "aes3k"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 
 #include <glib.h>
 #include <libusb.h>
 
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "aes3k.h"
 
diff --git a/libfprint/drivers/aes4000.c b/libfprint/drivers/aes4000.c
index d4f90b7..6118f33 100644
--- a/libfprint/drivers/aes4000.c
+++ b/libfprint/drivers/aes4000.c
@@ -26,13 +26,14 @@
 
 #define FP_COMPONENT "aes4000"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 
 #include <glib.h>
 #include <libusb.h>
 
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "aes3k.h"
 #include "driver_ids.h"
diff --git a/libfprint/drivers/aesx660.c b/libfprint/drivers/aesx660.c
index 98f6c75..ab67946 100644
--- a/libfprint/drivers/aesx660.c
+++ b/libfprint/drivers/aesx660.c
@@ -23,6 +23,8 @@
 
 #define FP_COMPONENT "aesX660"
 
+#include "fp_internal.h"
+
 #include <stdio.h>
 
 #include <errno.h>
@@ -32,7 +34,6 @@
 
 #include <assembling.h>
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "aesx660.h"
 
diff --git a/libfprint/drivers/elan.c b/libfprint/drivers/elan.c
index ccfd524..e528ecb 100644
--- a/libfprint/drivers/elan.c
+++ b/libfprint/drivers/elan.c
@@ -20,10 +20,11 @@
 
 #define FP_COMPONENT "elan"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <libusb.h>
 #include <assembling.h>
-#include <fp_internal.h>
 #include <fprint.h>
 
 #include "elan.h"
diff --git a/libfprint/drivers/etes603.c b/libfprint/drivers/etes603.c
index 9795757..60f81b2 100644
--- a/libfprint/drivers/etes603.c
+++ b/libfprint/drivers/etes603.c
@@ -33,6 +33,10 @@
  *
  */
 
+#define FP_COMPONENT "etes603"
+
+#include "fp_internal.h"
+
 #include <string.h>
 #include <stdint.h>
 #include <stdarg.h>
@@ -41,8 +45,6 @@
 #include <libusb.h>
 #include <glib.h>
 
-#define FP_COMPONENT "etes603"
-#include <fp_internal.h>
 #include "driver_ids.h"
 
 /* libusb defines */
diff --git a/libfprint/drivers/fdu2000.c b/libfprint/drivers/fdu2000.c
index e14b860..b95ff62 100644
--- a/libfprint/drivers/fdu2000.c
+++ b/libfprint/drivers/fdu2000.c
@@ -17,15 +17,16 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define FP_COMPONENT "fdu2000"
+
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
 
 #include <libusb.h>
 
-#define FP_COMPONENT "fdu2000"
-#include <fp_internal.h>
-
 #include "driver_ids.h"
 
 #ifndef HAVE_MEMMEM
diff --git a/libfprint/drivers/upeksonly.c b/libfprint/drivers/upeksonly.c
index 63c051e..4d228d9 100644
--- a/libfprint/drivers/upeksonly.c
+++ b/libfprint/drivers/upeksonly.c
@@ -25,14 +25,14 @@
 
 #define FP_COMPONENT "upeksonly"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
 #include <glib.h>
 #include <libusb.h>
 
-#include <fp_internal.h>
-
 #include <assembling.h>
 
 #include "upeksonly.h"
diff --git a/libfprint/drivers/upektc.c b/libfprint/drivers/upektc.c
index e4f0edc..107f93d 100644
--- a/libfprint/drivers/upektc.c
+++ b/libfprint/drivers/upektc.c
@@ -20,10 +20,11 @@
 
 #define FP_COMPONENT "upektc"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 #include <libusb.h>
-#include <fp_internal.h>
 
 #include "upektc.h"
 #include "driver_ids.h"
diff --git a/libfprint/drivers/upektc_img.c b/libfprint/drivers/upektc_img.c
index 843bcff..c193c07 100644
--- a/libfprint/drivers/upektc_img.c
+++ b/libfprint/drivers/upektc_img.c
@@ -19,13 +19,14 @@
 
 #define FP_COMPONENT "upektc_img"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
 #include <libusb.h>
 
 #include <aeslib.h>
-#include <fp_internal.h>
 
 #include "upektc_img.h"
 #include "driver_ids.h"
diff --git a/libfprint/drivers/upekts.c b/libfprint/drivers/upekts.c
index 4e572b9..d070404 100644
--- a/libfprint/drivers/upekts.c
+++ b/libfprint/drivers/upekts.c
@@ -27,14 +27,14 @@
 
 #define FP_COMPONENT "upekts"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 
 #include <glib.h>
 #include <libusb.h>
 
-#include <fp_internal.h>
-
 #include "driver_ids.h"
 
 #define EP_IN (1 | LIBUSB_ENDPOINT_IN)
diff --git a/libfprint/drivers/uru4000.c b/libfprint/drivers/uru4000.c
index 286f3d9..600bb27 100644
--- a/libfprint/drivers/uru4000.c
+++ b/libfprint/drivers/uru4000.c
@@ -20,6 +20,8 @@
 
 #define FP_COMPONENT "uru4000"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
@@ -28,8 +30,6 @@
 #include <pk11pub.h>
 #include <libusb.h>
 
-#include <fp_internal.h>
-
 #include "driver_ids.h"
 
 #define EP_INTR			(1 | LIBUSB_ENDPOINT_IN)
diff --git a/libfprint/drivers/vcom5s.c b/libfprint/drivers/vcom5s.c
index 528dd47..dfbdca7 100644
--- a/libfprint/drivers/vcom5s.c
+++ b/libfprint/drivers/vcom5s.c
@@ -19,6 +19,8 @@
 
 #define FP_COMPONENT "vcom5s"
 
+#include "fp_internal.h"
+
 /* TODO:
  * calibration?
  * image size: windows gets 300x300 through vpas enrollment util?
@@ -32,8 +34,6 @@
 #include <glib.h>
 #include <libusb.h>
 
-#include <fp_internal.h>
-
 #include "driver_ids.h"
 
 #define CTRL_IN 0xc0
diff --git a/libfprint/drivers/vfs0050.c b/libfprint/drivers/vfs0050.c
index 31d793c..45adaa4 100644
--- a/libfprint/drivers/vfs0050.c
+++ b/libfprint/drivers/vfs0050.c
@@ -19,9 +19,10 @@
 
 #define FP_COMPONENT "vfs0050"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <string.h>
-#include <fp_internal.h>
 #include <assembling.h>
 #include "driver_ids.h"
 
diff --git a/libfprint/drivers/vfs101.c b/libfprint/drivers/vfs101.c
index 625a411..afc72d9 100644
--- a/libfprint/drivers/vfs101.c
+++ b/libfprint/drivers/vfs101.c
@@ -17,14 +17,14 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define FP_COMPONENT "vfs101"
+
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 
-#define FP_COMPONENT "vfs101"
-
-#include <fp_internal.h>
-
 #include "driver_ids.h"
 
 /* Input-Output usb endpoint */
diff --git a/libfprint/drivers/vfs301.c b/libfprint/drivers/vfs301.c
index 833c05b..1b8a7db 100644
--- a/libfprint/drivers/vfs301.c
+++ b/libfprint/drivers/vfs301.c
@@ -21,6 +21,8 @@
 
 #define FP_COMPONENT "vfs301"
 
+#include "fp_internal.h"
+
 #include <errno.h>
 #include <signal.h>
 #include <string.h>
@@ -32,8 +34,6 @@
 #include "vfs301_proto.h"
 #include <unistd.h>
 
-#include <fp_internal.h>
-
 #include "driver_ids.h"
 
 /************************** GENERIC STUFF *************************************/
diff --git a/libfprint/drv.c b/libfprint/drv.c
index a7ba846..719417d 100644
--- a/libfprint/drv.c
+++ b/libfprint/drv.c
@@ -19,11 +19,11 @@
 
 #define FP_COMPONENT "drv"
 
+#include "fp_internal.h"
+
 #include <config.h>
 #include <errno.h>
 
-#include "fp_internal.h"
-
 /* SSM: sequential state machine
  * Asynchronous driver design encourages some kind of state machine behind it.
  * In most cases, the state machine is entirely linear - you only go to the
diff --git a/libfprint/fp_internal.h b/libfprint/fp_internal.h
index fdaa408..3cf5629 100644
--- a/libfprint/fp_internal.h
+++ b/libfprint/fp_internal.h
@@ -21,8 +21,13 @@
 #define __FPRINT_INTERNAL_H__
 
 #include <config.h>
-#include <stdint.h>
 
+#ifdef FP_COMPONENT
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "libfprint-"FP_COMPONENT
+#endif
+
+#include <stdint.h>
 #include <glib.h>
 #include <libusb.h>
 
@@ -34,26 +39,10 @@
         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
         (type *)( (char *)__mptr - offsetof(type,member) );})
 
-enum fpi_log_level {
-	FPRINT_LOG_LEVEL_DEBUG,
-	FPRINT_LOG_LEVEL_INFO,
-	FPRINT_LOG_LEVEL_WARNING,
-	FPRINT_LOG_LEVEL_ERROR,
-};
-
-void fpi_log(enum fpi_log_level, const char *component, const char *function,
-	const char *format, ...);
-
-#ifndef FP_COMPONENT
-#define FP_COMPONENT NULL
-#endif
-
-#define _fpi_log(level, fmt...) fpi_log(level, FP_COMPONENT, __FUNCTION__, fmt)
-
-#define fp_dbg(fmt...) _fpi_log(FPRINT_LOG_LEVEL_DEBUG, fmt)
-#define fp_info(fmt...) _fpi_log(FPRINT_LOG_LEVEL_INFO, fmt)
-#define fp_warn(fmt...) _fpi_log(FPRINT_LOG_LEVEL_WARNING, fmt)
-#define fp_err(fmt...) _fpi_log(FPRINT_LOG_LEVEL_ERROR, fmt)
+#define fp_dbg g_debug
+#define fp_info g_debug
+#define fp_warn g_warning
+#define fp_err g_error
 
 #ifndef NDEBUG
 #define BUG_ON(condition) \
diff --git a/libfprint/poll.c b/libfprint/poll.c
index 7557bb0..c820103 100644
--- a/libfprint/poll.c
+++ b/libfprint/poll.c
@@ -19,6 +19,8 @@
 
 #define FP_COMPONENT "poll"
 
+#include "fp_internal.h"
+
 #include <config.h>
 #include <errno.h>
 #include <time.h>
@@ -27,8 +29,6 @@
 #include <glib.h>
 #include <libusb.h>
 
-#include "fp_internal.h"
-
 /**
  * SECTION:events
  * @title: Initialisation and events handling
diff --git a/libfprint/sync.c b/libfprint/sync.c
index c324e0b..c194f5c 100644
--- a/libfprint/sync.c
+++ b/libfprint/sync.c
@@ -19,11 +19,11 @@
 
 #define FP_COMPONENT "sync"
 
+#include "fp_internal.h"
+
 #include <config.h>
 #include <errno.h>
 
-#include "fp_internal.h"
-
 struct sync_open_data {
 	struct fp_dev *dev;
 	int status;
diff --git a/meson.build b/meson.build
index 93603b6..c11b3fd 100644
--- a/meson.build
+++ b/meson.build
@@ -9,6 +9,7 @@ project('libfprint', [ 'c', 'cpp' ],
         meson_version: '>= 0.45.0')
 
 add_project_arguments([ '-D_GNU_SOURCE' ], language: 'c')
+add_project_arguments([ '-DG_LOG_DOMAIN="libfprint"' ], language: 'c')
 
 libfprint_conf = configuration_data()