Add an error type for circular references

include/akerror.tmpl.h

@@ -6,13 +6,19 @@
 #include <stdbool.h>
 #include <string.h>
 #include <stdio.h>
+#include <limits.h>
 #endif
 
-#define AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH              1024
+// FIXME: This is huge now. It used to be 1000 bytes, then I wanted to report errors
+// related to filesystem paths, which made it grow beyond PATH_MAX, then I started
+// reporting messages including 2 file paths (PATH_MAX * 2), so now to make the compiler warnings
+// shut up, it's enormous (PATH_MAX*3).
+#define AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH              12384
+
 #define AKERR_MAX_ERROR_NAME_LENGTH                        64
-#define AKERR_MAX_ERROR_FNAME_LENGTH                       256
+#define AKERR_MAX_ERROR_FNAME_LENGTH                       PATH_MAX
 #define AKERR_MAX_ERROR_FUNCTION_LENGTH                    128
-#define AKERR_MAX_ERROR_STACKTRACE_BUF_LENGTH              2048
+#define AKERR_MAX_ERROR_STACKTRACE_BUF_LENGTH              (AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH + AKERR_MAX_ERROR_NAME_LENGTH + AKERR_MAX_ERROR_FNAME_LENGTH + AKERR_MAX_ERROR_FUNCTION_LENGTH + 16)
 
 #define AKERR_LAST_ERRNO_VALUE      AKERR_LAST_ERRNO_VALUE_SED
 
@@ -31,6 +37,7 @@
 #define AKERR_BEHAVIOR              (AKERR_LAST_ERRNO_VALUE + 13)
 #define AKERR_RELATIONSHIP          (AKERR_LAST_ERRNO_VALUE + 14)
 #define AKERR_EOF                   (AKERR_LAST_ERRNO_VALUE + 15)
+#define AKERR_CIRCULAR_REFERENCE    (AKERR_LAST_ERRNO_VALUE + 16)
 
 #ifndef AKERR_MAX_ERR_VALUE
 #define AKERR_MAX_ERR_VALUE (AKERR_LAST_ERRNO_VALUE + 15)
@@ -74,6 +81,7 @@ char *akerr_name_for_status(int status, char *name);
 void akerr_init();
 void akerr_default_handler_unhandled_error(akerr_ErrorContext *ptr);
 void akerr_default_logger(const char *f, ...);
+int akerr_valid_error_address(akerr_ErrorContext *ptr);
 /* defined in src/errno.c which is built dynamically at build time from system errno definitions */
 void akerr_init_errno(void);
 
@@ -179,6 +187,7 @@ void akerr_init_errno(void);
 #define VALID(__err_context, __stmt)                       \
     __stmt;                                                \
     if ( akerr_valid_error_address(__err_context) == 0 ) { \
+	__err_context = NULL;                              \
 	FAIL(__err_context, AKERR_BEHAVIOR, "Received (akerr_Error *) from an invalid memory region. (Did the method finish without calling SUCCEED_RETURN?)"); \
     }
 

src/error.c

@@ -17,7 +17,11 @@ akerr_ErrorContext AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR];
 int akerr_valid_error_address(akerr_ErrorContext *ptr)
 {
     // Is this within the memory region occupied by AKERR_ARRAY_ERROR?
-    return ((ptr >= &AKERR_ARRAY_ERROR[0]) && (ptr <= &AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR-1]));
+    if ( ptr == NULL ) {
+	return 1;
+    }
+    return ((ptr >= &AKERR_ARRAY_ERROR[0]) &&
+	    (ptr <= &AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR-1]));
 }
 
 void akerr_default_logger(const char *fmt, ...)
@@ -65,6 +69,7 @@ void akerr_init()
 	akerr_name_for_status(AKERR_VALUE, "Value Error");
 	akerr_name_for_status(AKERR_BEHAVIOR, "Behavior Error");
 	akerr_name_for_status(AKERR_RELATIONSHIP, "Relationship Error");
+	akerr_name_for_status(AKERR_CIRCULAR_REFERENCE, "Circular Reference Error");
 #if (defined(AKERR_USE_STDLIB) && AKERR_USE_STDLIB == 1) || (!defined(AKERR_USE_STDLIB))
 	akerr_init_errno();
 #endif