# HG changeset patch
# User John W. Eaton <jwe@octave.org>
# Date 1711388987 14400
# Node ID 93b856b2d87e70b09fe79e36452a013abb0794a5
# Parent  40fde86be9b00fa113967c167627d9158b27bc73
don't allow error_if and error_unless macros to be defined to be empty

* error.h (error_if, error_unless): Don't allow these macros to be
defined away by compiling with NDEBUG defined.  Update comments to
discourage using error_if, error_impossible, and error_unless.

diff -r 40fde86be9b0 -r 93b856b2d87e libinterp/corefcn/error.h
--- a/libinterp/corefcn/error.h	Mon Mar 25 00:42:04 2024 -0400
+++ b/libinterp/corefcn/error.h	Mon Mar 25 13:49:47 2024 -0400
@@ -493,20 +493,23 @@
 extern OCTINTERP_API void
 parse_error_with_id (const char *id, const char *fmt, ...);
 
+// Use of the following macros (error_impossible, error_if, and
+// error_unless) is discouraged.  All of these will only display a
+// generic error of the form
+//
+//   impossible state reached in file 'FILE' at line 'N'
+//
+// If the state really is "impossible" to reach, then it is better to
+// use one of the corresponding panic* functions instead (see panic.h).
+//
+// See also the discussion here: https://octave.discourse.group/t/assert-panic-error-and-ndebug/5409
+
 #define error_impossible()                                              \
   ::error ("impossible state reached in file '%s' at line %d", __FILE__, __LINE__)
 
-#if defined (NDEBUG)
-#  define error_if(cond)
-#else
-#  define error_if(cond) do { if (cond) error_impossible (); } while (0)
-#endif
+#define error_if(cond) do { if (cond) error_impossible (); } while (0)
 
-#if defined (NDEBUG)
-#  define error_unless(cond)
-#else
-#  define error_unless(cond) error_if (! (cond))
-#endif
+#define error_unless(cond) error_if (! (cond))
 
 OCTAVE_BEGIN_NAMESPACE(octave)