1 files changed, 176 insertions, 0 deletions
diff --git a/include/sane/sanei_debug.h b/include/sane/sanei_debug.h
new file mode 100644
index 0000000..5cf2e45
--- /dev/null
+++ b/include/sane/sanei_debug.h
@@ -0,0 +1,176 @@
+/** @file sanei_debug.h
+ * Support for printing debug messages.
+ *
+ * Use the functions of this header file to print debug or warning messages.
+ */
+
+#ifndef _SANEI_DEBUG_H
+#define _SANEI_DEBUG_H
+
+#include <sane/sanei.h>
+
+/** @name Public macros
+ * These macros can be used in backends and other SANE-related
+ * code.
+ *
+ * Before including sanei_debug.h, the following macros must be set:
+ *
+ * - BACKEND_NAME - The name of your backend without double-quotes (must be set in any case)
+ * - STUBS - If this is defined, no macros will be included. Used in 
+ *   backends consisting of more than one .c file.
+ * - DEBUG_DECLARE_ONLY - Generates prototypes instead of functions. Used in 
+ *   backends consisting of more than one .c file.
+ * - DEBUG_NOT_STATIC - Doesn't generate static functions. Used in header files if
+ *   they are include in more than one .c file.
+ *
+ * @{ 
+ */
+
+/** @def DBG_INIT()
+ * Initialize sanei_debug.
+ *
+ * Call this function before you use any DBG function.
+ */
+
+/** @def DBG(level, fmt, ...)
+ * Print a message at debug level `level' or higher using a printf-like
+ * function. Example: DBG(1, "sane_open: opening fd \%d\\n", fd).
+ *
+ * @param level debug level
+ * @param fmt format (see man 3 printf for details)
+ * @param ... additional arguments
+ */
+
+/** @def IF_DBG(x)
+ * Compile code only if debugging is enabled.
+ *
+ * Expands to x if debug support is enabled at compile-time. If NDEBUG is 
+ * defined at compile-time this macro expands to nothing.
+ *
+ * @param x code to expand when debugging is enabled
+ */
+
+/**
+ * @def DBG_LEVEL
+ * Current debug level. 
+ *
+ * You can only read this "variable".
+ */
+
+/** @def ENTRY(name)
+ * Expands to sane_BACKEND_NAME_name.
+ *
+ * Example: ENTRY(init) in mustek.c will expand to sane_mustek_init.
+ */
+
+/* @} */
+
+/** @name Internal macros and functions
+ * Do not use in your own code.
+ * @{
+ */
+
+/** @def DBG_LOCAL
+ * Do not use in backends directly.
+ *
+ * Internal wrapper for printing function.
+ */
+
+/** @fn extern void sanei_init_debug (const char * backend, int * debug_level_var);
+ * Do not use in backends directly.
+ *
+ * Actual init function.
+ */
+
+/** @fn extern void sanei_debug_msg (int level, int max_level, const char *be, const char *fmt, va_list ap);
+ * Do not use in backends directly.
+ *
+ * Actual printing function.
+ */
+/* @} */
+
+                                  /** @hideinitializer*/
+#define ENTRY(name)     PASTE(PASTE(PASTE(sane_,BACKEND_NAME),_),name)
+
+#ifdef NDEBUG
+  
+extern void sanei_debug_ndebug (int level, const char *msg, ...);
+	
+# define DBG_LEVEL	(0)
+# define DBG_INIT()
+# define DBG		sanei_debug_ndebug
+# define IF_DBG(x)
+	
+#else /* !NDEBUG */
+	
+                                  /** @hideinitializer*/
+# define DBG_LEVEL      PASTE(sanei_debug_,BACKEND_NAME)
+
+# if defined(BACKEND_NAME) && !defined(STUBS)
+#  ifdef DEBUG_DECLARE_ONLY
+extern int DBG_LEVEL;
+#  else /* !DEBUG_DECLARE_ONLY */
+int DBG_LEVEL = 0;
+#  endif /* DEBUG_DECLARE_ONLY */
+# endif /* BACKEND_NAME && !STUBS */
+
+                                  /** @hideinitializer*/
+# define DBG_INIT()                                     \
+  sanei_init_debug (STRINGIFY(BACKEND_NAME), &DBG_LEVEL)
+
+                                  /** @hideinitializer*/
+# define DBG_LOCAL	PASTE(DBG_LEVEL,_call)
+
+
+# ifndef STUBS
+
+#  ifdef DEBUG_DECLARE_ONLY
+
+extern void DBG_LOCAL (int level, const char *msg, ...) 
+#ifdef __GNUC__
+__attribute__ ((format (printf, 2, 3)))
+#endif
+;
+
+#  else /* !DEBUG_DECLARE_ONLY */
+
+#   include <stdarg.h>
+	
+extern void sanei_debug_msg 
+  (int level, int max_level, const char *be, const char *fmt, va_list ap);
+
+#ifdef __GNUC__
+#   ifndef DEBUG_NOT_STATIC
+static
+#   endif /* !DEBUG_NOT_STATIC */
+void DBG_LOCAL (int level, const char *msg, ...) __attribute__ ((format (printf, 2, 3)));
+#endif /* __GNUC__ */
+
+#   ifndef DEBUG_NOT_STATIC
+static
+#   endif /* !DEBUG_NOT_STATIC */
+void
+DBG_LOCAL (int level, const char *msg, ...)
+{
+  va_list ap;
+
+  va_start (ap, msg);
+  sanei_debug_msg (level, DBG_LEVEL, STRINGIFY(BACKEND_NAME), msg, ap);
+  va_end (ap);
+}
+
+#  endif /* DEBUG_DECLARE_ONLY */
+
+# endif /* !STUBS */
+
+                                  /** @hideinitializer*/
+# define DBG            DBG_LOCAL
+
+extern void sanei_init_debug (const char * backend, int * debug_level_var);
+  
+                                  /** @hideinitializer*/
+# define IF_DBG(x)      x
+
+#endif /* NDEBUG */
+
+#endif /* _SANEI_DEBUG_H */