I'm writing some code that depends on sizeof(wchar_t). If sizeof(wchar_t) > 2 I'm doing one things, if sizeof(wchar_t) = 2 - another things. I need to determine sizeof(wchar_t) in precompiler. How can I do this?
My logic is: sizeof(wchar_t) is given by gcc. I can use --with-target-short-wchar gcc's configure script option and gcc will generate 2-byte wchar_t variables. Therefore, there must be some predefined GCC's macro using which I can determine the size of wchar_t. Right?
The code for which I need to know sizeof(wchar_t) is written for Newlib (small standard C library). As I understand situation with wchar_t is similar to situation with other basic C types - they are defined with help of gcc's stddef.h or limits.h.
llewelly advised me to use WCHAR_MAX macro.
I tried to use something like this:
#if WCHAR_MAX > 0xFFFF blablabla #else blablabla #endif
But to my surprise I've found out that I have WCHAR_MAX==0x7FFFFFFFu when sizeof(wchar_t)==2! I've seen into wchar.h of Newlib - there is something like
#ifndef _WCHAR_MAX #define WCHAR_MAX 0x7FFFFFFFu #else #define WCHAR_MAX _WCHAR_MAX #else
This is similar to defines of other limits macros. I've seen to GCC's headers and not found any _WCHAR_MAX reference there.
I have seen to other libc's (FreeBSD's and Glibc) - they also rely on _WCHAR_MAX, but _WCHAR_MAX isn't from GCC, but is from target-depended files (also placed in that libc) as I've understood.
Therefore I can conclude that sizeof(wchar_t) is considered as target-dependent. An I can't vary gcc (using or not --with-target-short-wchar option when compiling it)...
But I want to have one target that is built differently depending on sizeof(wchar_t) that is defined by GCC. How can I do this?
One obvious way is to use construction like
if (sizeof(wchar_t) > 2)
{
blablabala
}
else
{
blablabla
}but I want to rely on precompiler, not on compiler.
What should I do?
Thanks.
P.S. Please, CC to me if answer...
-- Best Regards, Artem B. Bityuckiy, St.-Petersburg, Russia.
