Merge all compatibility macros around __func__ and __FUNCTION__

Various parts of SANE introduced their own compatibility macros for
old compilers that don't support __func__.  Most of these definitions
are identical or have minor differences.  This patch replaces them
with a single instance in the central header file for backends.

backend/epson2.h

@@ -45,13 +45,6 @@
 #include "sane/sanei_backend.h"
 #include "sane/sanei_debug.h"
 
-#ifdef __GNUC__
-#define __func__ __FUNCTION__
-#else
-#define __func__ "(undef)"
-/* I cast my vote for C99... :) */
-#endif
-
 #define EPSON2_CONFIG_FILE "epson2.conf"
 
 #ifndef PATH_MAX

backend/epsonds.h

@@ -43,13 +43,6 @@
 #include "sane/sanei_usb.h"
 #include "sane/sanei_jpeg.h"
 
-#ifdef __GNUC__
-#define __func__ __FUNCTION__
-#else
-#define __func__ "(undef)"
-/* I cast my vote for C99... :) */
-#endif
-
 #define EPSONDS_CONFIG_FILE "epsonds.conf"
 
 #ifndef PATH_MAX

backend/gt68xx_low.h

@@ -73,9 +73,6 @@
 
 /* return if an error occured while the function was called */
 #ifdef MAX_DEBUG
-#  ifndef __FUNCTION__
-#    define __FUNCTION__ "somewhere"
-#  endif
 
 #  define RIE(function) \
   do \

backend/kodakaio.h

@@ -46,12 +46,6 @@
 #include "../include/sane/sanei_debug.h"
 #include "../include/sane/sanei_backend.h"
 
-#ifdef __GNUC__
-#define __func__ __FUNCTION__
-#else
-#define __func__ "(undef)"
-#endif
-
 /* Silence the compiler for unused arguments */
 #define NOT_USED(x) ( (void)(x) )
 

backend/magicolor.h

@@ -44,13 +44,6 @@
 #include "../include/sane/sanei_debug.h"
 #include "../include/sane/sanei_backend.h"
 
-#ifdef __GNUC__
-#define __func__ __FUNCTION__
-#else
-#define __func__ "(undef)"
-/* I cast my vote for C99... :) */
-#endif
-
 /* Silence the compiler for unused arguments */
 #define NOT_USED(x) ( (void)(x) )
 

backend/snapscan-sources.c

@@ -105,10 +105,6 @@ I hope this makes sense to you (and I got the right idea of the original author'
 intention).
 ***********************************************************************************/
 
-#ifndef __FUNCTION__
-#define __FUNCTION__ "(undef)"
-#endif
-
 static SANE_Status Source_init (Source *pself,
                                 SnapScan_Scanner *pss,
                                 SourceRemaining remaining,

backend/umax_pp.h

@@ -193,13 +193,6 @@ enum Umax_PP_Configure_Option
   NUM_CFG_OPTIONS
 };
 
-#if (!defined __GNUC__ || __GNUC__ < 2 || \
-     __GNUC_MINOR__ < (defined __cplusplus ? 6 : 4))
-
-#define __PRETTY_FUNCTION__	"umax_pp"
-
-#endif
-
 #define DEBUG()		DBG(4, "%s(v%d.%d.%d-%s): line %d: debug exception\n", \
 			  __PRETTY_FUNCTION__, SANE_CURRENT_MAJOR, V_MINOR,	\
 			  UMAX_PP_BUILD, UMAX_PP_STATE, __LINE__)

include/sane/sanei_backend.h

@@ -28,6 +28,16 @@
  */
 #include <sane/sanei_debug.h>
 
+#if __STDC_VERSION__ >= 199901L
+/* __func__ is provided */
+#elif __GNUC__ >= 5
+/* __func__ is provided */
+#elif __GNUC__ >= 2
+# define __func__ __FUNCTION__
+#else
+# define __func__ "(unknown)"
+#endif
+
 #ifdef HAVE_SYS_HW_H
   /* OS/2 i/o-port access compatibility macros: */
 # define inb(p)         _inp8 (p)

sanei/sanei_usb.c

@@ -62,15 +62,6 @@
 #include <dirent.h>
 #include <time.h>
 
-/* for debug messages */
-#if __STDC_VERSION__ < 199901L
-# if __GNUC__ >= 2
-#  define __func__ __FUNCTION__
-# else
-#  define __func__ "<unknown>"
-# endif
-#endif
-
 
 #ifdef HAVE_RESMGR
 #include <resmgr.h>