define jbyte as signed char

[Yuri Dario]

In the OS/2 sdk, jni_mh.h defines the following types:

#ifdef __GNUC__
typedef int jint;
typedef __int64_t jlong;
typedef char jbyte;
#else
typedef long jint;
typedef __int64 jlong;
typedef signed char jbyte;
#endif

but the GNUC defines are different from default ones on other platforms.

When building Apache OpenOffice, errors are issued because there isn't a direct cast from signed char to char, even if signed char is the default setting (they are treated as different types).

[dmik]

Corrected your description. It contained a wrong excerpt, probably the one you have already fixed (instead of the original one). Also, please don't forget to use and when pasting code samples here, otherwise formatting gets broken.

[dmik]

Regarding the matter. I used signed char instead of just char for jbyte to make it compatible with char arrays used everywhere in the C/C++ code in Hotspot/JDK (which saved me from many warnings and sometimes from errors), see r329. On Windows such a difference is not a problem since MSVC ignores it.

However, I didn't notice that on *nix platforms it's also defined as signed char. But GCC compiler is used there as well, this means they somehow solve this difference problem. Quick search through the sources shows that they simply use C-style casts, like (char *) jbytebuf or (jbyte *) charbuf - the thing that I wanted to avoid.

Anyway, given that jbyte is signed char on all platforms but OS/2, for the sake of compatibility I give up. I will have to change it to signed char and fix all casting warnings/errors manually as described above. This ticket will track the task.