diff options
Diffstat (limited to 'src/lisp.h')
| -rw-r--r-- | src/lisp.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/lisp.h b/src/lisp.h index a9e7354f9fc..a46436e718b 100644 --- a/src/lisp.h +++ b/src/lisp.h @@ -763,6 +763,12 @@ extern EMACS_INT string_bytes (struct Lisp_String *); #endif /* not GC_CHECK_STRING_BYTES */ +/* A string cannot contain more bytes than a fixnum can represent, + nor can it be so long that C pointer arithmetic stops working on + the string plus a terminating null. */ +#define STRING_BYTES_MAX \ + min (MOST_POSITIVE_FIXNUM, min (SIZE_MAX, PTRDIFF_MAX) - 1) + /* Mark STR as a unibyte string. */ #define STRING_SET_UNIBYTE(STR) \ do { if (EQ (STR, empty_multibyte_string)) \ |