Fix proper support of no stdio

and add macro M_RAISE_FATAL to raise a fatal error
with the default is using stdio.

m-core.h

@@ -41,10 +41,6 @@
 #endif
 #if M_USE_STDIO
 # include <stdio.h>
-#else
-#if !defined(M_MEMORY_FULL) || !defined(M_ASSERT_INIT)
-# error Without stdio.h, definitions for macros M_MEMORY_FULL, M_ASSERT_INIT are mandatory.
-#endif
 #endif
 
 /* By default, always use stdarg. Can be turned off in specific environment if needed
@@ -286,15 +282,13 @@ M_BEGIN_PROTECTED_CODE
 #endif
 
 /* This macro is called on memory allocation failure.
- * By default, it aborts the program execution.
+ * By default, it raises a fatal error.
  * NOTE: Can be overloaded by user code.
 */
 #ifndef M_MEMORY_FULL
-#define M_MEMORY_FULL(size) do {                                              \
+#define M_MEMORY_FULL(size)                                                   \
-    fprintf(stderr, "ERROR(M*LIB): Cannot allocate %zu bytes of memory at (%s:%s:%d).\n", \
+  M_RAISE_FATAL("Cannot allocate %zu bytes of memory at (%s:%s:%d).\n",       \
-            (size_t) (size), __FILE__, __func__, __LINE__);                   \
+                (size_t) (size), __FILE__, __func__, __LINE__)
-    abort();                                                                  \
-  } while (0)
 #endif
 
 
@@ -302,6 +296,28 @@ M_BEGIN_PROTECTED_CODE
 /*********************  ERROR handling **********************/
 /************************************************************/
 
+/* Raise a fatal error and terminate the current execution flow.
+   Default behavior performs the following actions:
+    * format and print the error message on stderr
+    * terminate the program.
+   Can be overloaded by the user code.
+   Usage:
+    M_RAISE_FATAL(message, ...)
+  with
+    message, a printf formatted message associated to the error
+*/
+#ifndef M_RAISE_FATAL
+#if M_USE_STDIO == 1
+#define M_RAISE_FATAL(...) do {                                               \
+    fprintf(stderr, "ERROR(M*LIB): " __VA_ARGS__);                            \
+    abort();                                                                  \
+  } while (0)
+#else
+# error Without stdio.h, definitions for macro M_RAISE_FATAL is mandatory.
+#endif
+#endif
+
+
 /* Define the default assertion macro used by M*LIB.
  * By default, it is an encapsulation of CLIB assert.
  * NOTE: Can be overiden by user if it needs to keep finer access 
@@ -333,9 +349,8 @@ M_BEGIN_PROTECTED_CODE
 #ifndef M_ASSERT_INIT
 #define M_ASSERT_INIT(expr, object) {                                         \
     if (!(expr)) {                                                            \
-      fprintf(stderr, "ERROR(M*LIB): Cannot initialize %s at (%s:%s:%d): %s\n", \
+      M_RAISE_FATAL("Cannot initialize %s at (%s:%s:%d): %s\n",               \
                   (object), __FILE__, __func__, __LINE__, #expr);             \
-      abort();                                                                \
     } } while (0)
 #endif