Updated debug_print(): Enhanced Adaptability for Various Environments

The debug_print() function has been updated for better adaptability.
It now integrates with diverse environments through the customized
implementation of the cmp_debug_puts() function.

lib/common/cmp_debug.c

+/**
+ * @file   cmp_debug.c
+ * @author Dominik Loidolt (dominik.loidolt@univie.ac.at)
+ * @date   2024
+ *
+ * @copyright GPLv2
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * @brief compression/decompression debugging printing functions
+ */
+
+
+#ifndef ICU_ASW
+#  include <stdio.h>
+#endif
+#include <string.h>
+#include <stdarg.h>
+
+#include "cmp_debug.h"
+#include "compiler.h"
+#include "vsnprintf.h"
+
+
+/**
+ * @brief outputs a debug string
+ *
+ * This function outputs a string for debugging purposes
+ *
+ * @param str The string to output
+ */
+
+static void cmp_debug_puts(const char *str)
+{
+#ifdef ICU_ASW
+	/* XXX adapt it to your needs */
+	/* asw_puts(str); */
+	(void)str;
+#else
+	fputs(str, stderr);
+	fputs("\n", stderr);
+#endif
+}
+
+
+/**
+ * @brief implements debug printing
+ *
+ * This function formats a string and prints it for debugging. It uses a static
+ * buffer to format the string
+ *
+ * @param fmt	pointer to a null-terminated byte string specifying how to
+ *		interpret the data
+ * @param ...	arguments specifying data to print
+ */
+
+void cmp_debug_print_impl(const char *fmt, ...)
+{
+	static char print_buffer[PRINT_BUFFER_SIZE];
+	int len;
+	va_list args;
+
+	va_start(args, fmt);
+	len = my_vsnprintf(print_buffer, sizeof(print_buffer)-1, fmt, args);
+	va_end(args);
+
+	if (len < 0) {
+		const char str[] = "my_snprintf is broken";
+
+		compile_time_assert(sizeof(str) <= sizeof(print_buffer), CMP_DEBUG_PRINT_BUFFER_SIZE_TO_SMALL);
+		memcpy(print_buffer, str, sizeof(str));
+	}
+	if ((size_t)len >= sizeof(print_buffer)-1) {
+		const char str[] =  "cmp_debug print_buffer too small";
+
+		compile_time_assert(sizeof(str) <= sizeof(print_buffer), CMP_DEBUG_PRINT_BUFFER_SIZE_TO_SMALL);
+		memcpy(print_buffer, str, sizeof(str));
+	}
+
+	cmp_debug_puts(print_buffer);
+}

lib/common/cmp_debug.h

@@ -13,7 +13,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
- * @brief compression/decompression debugging defines
+ * @brief compression/decompression debugging printing functions
  */
 
 #ifndef CMP_DEBUG_H
@@ -26,17 +26,16 @@
 #  define DEBUGLEVEL 0
 #endif
 
-#if !defined(ICU_ASW) && (defined(DEBUG) || DEBUGLEVEL > 0)
-	#include <stdio.h>
+
+#define PRINT_BUFFER_SIZE 256
+
 __extension__
-	#define debug_print(...)			\
-		do {					\
-			fprintf(stderr, __VA_ARGS__);	\
-			fprintf(stderr, "\n");		\
-		} while (0)
+#if (defined(DEBUG) || DEBUGLEVEL > 0)
+#  define debug_print(...) cmp_debug_print_impl(__VA_ARGS__)
 #else
-	#define debug_print(...) \
-		do {} while (0)
+#  define debug_print(...) do {} while (0)
 #endif
 
+void cmp_debug_print_impl(const char *fmt, ...);
+
 #endif /* CMP_DEBUG_H */

lib/common/compiler.h

@@ -37,13 +37,6 @@
 #endif
 
 
-/**
- * Compile time check usable outside of function scope.
- * Stolen from Linux (hpi_internal.h)
- */
-#define compile_time_assert(cond, msg) typedef char ASSERT_##msg[(cond) ? 1 : -1]
-
-
 /**
  * same with the stuff below
  */
@@ -127,7 +120,7 @@
  * It also tries to prevent the actual use of the "unused" variables.
  */
 
-#if GNUC_PREREQ(4, 5)
+#if GNUC_PREREQ(4, 5) || defined(__clang__)
 #define UNUSED __attribute__((unused)) \
 	__attribute__((deprecated ("parameter declared as UNUSED")))
 #elif defined(__GNUC__)
@@ -154,4 +147,11 @@
 #endif
 
 
+/**
+ * Compile time check usable outside of function scope.
+ * Stolen from Linux (hpi_internal.h)
+ */
+#define compile_time_assert(cond, msg) UNUSED typedef char ASSERT_##msg[(cond) ? 1 : -1]
+
+
 #endif /* COMPILER_H */

lib/common/meson.build

 common_sources = files([
   'cmp_data_types.c',
+  'cmp_debug.c',
   'cmp_entity.c',
   'cmp_max_used_bits.c',
-  'cmp_support.c'
+  'cmp_support.c',
+  'vsnprintf.c'
 ])

lib/common/vsnprintf.h

+/**
+ * @file   vsnprintf.h
+ * @author Dominik Loidolt (dominik.loidolt@univie.ac.at)
+ * @date   2024
+ *
+ * @copyright GPLv2
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * @brief Tiny vsnprintf implementation
+ */
+
+
+#ifndef VSNPRINTF_H
+#define VSNPRINTF_H
+
+int my_vsnprintf(char* buffer, size_t count, const char* format, va_list va);
+
+#endif /* VSNPRINTF_H */