diff options
Diffstat (limited to 'erts/emulator/beam/erl_term.h')
| -rw-r--r-- | erts/emulator/beam/erl_term.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/erts/emulator/beam/erl_term.h b/erts/emulator/beam/erl_term.h index 3dd1c2555c..18483fca35 100644 --- a/erts/emulator/beam/erl_term.h +++ b/erts/emulator/beam/erl_term.h @@ -1,7 +1,7 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 2000-2017. All Rights Reserved. + * Copyright Ericsson AB 2000-2018. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -345,6 +345,9 @@ _ET_DECLARE_CHECKED(Uint,thing_subtag,Eterm) * * To help find code which makes unwarranted assumptions about zero, * we now use a non-zero bit-pattern in debug mode. + * + * In order to be able to differentiata against values, the non-value + * needs to be tagged as a header of some sort. */ #if ET_DEBUG # ifdef HIPE @@ -355,7 +358,7 @@ _ET_DECLARE_CHECKED(Uint,thing_subtag,Eterm) # define THE_NON_VALUE _make_header(0,_TAG_HEADER_FLOAT) # endif #else -#define THE_NON_VALUE (0) +#define THE_NON_VALUE (TAG_PRIMARY_HEADER) #endif #define is_non_value(x) ((x) == THE_NON_VALUE) #define is_value(x) ((x) != THE_NON_VALUE) |