diff options
Diffstat (limited to 'ndk/platforms/android-3/include/sys/cdefs.h')
| -rw-r--r-- | ndk/platforms/android-3/include/sys/cdefs.h | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/ndk/platforms/android-3/include/sys/cdefs.h b/ndk/platforms/android-3/include/sys/cdefs.h index 27c575c87..88ce720b2 100644 --- a/ndk/platforms/android-3/include/sys/cdefs.h +++ b/ndk/platforms/android-3/include/sys/cdefs.h @@ -37,11 +37,36 @@ #ifndef _SYS_CDEFS_H_ #define _SYS_CDEFS_H_ - -/* our implementation of wchar_t is only 8-bit - die die non-portable code */ +/* In previous NDK releases, wchar_t was defined as 'unsigned char' + * when targetting API level < 9 (i.e. Froyo or older). + * + * This is no longer the case, but you can define _WCHAR_IS_8BIT + * at compile time to restore the old behaviour. + * + * The reason for this redefine is purely historical. Until Android 2.3, + * i.e. API level 9, there was absolutely no official support for wchar_t + * in the C library, but compiling GCC and the GNU libstdc++ required a + * working <wchar.h>. + * + * To allow this while keeping the C library small, wchar_t was redefined + * explicitely as an 8-bit unsigned integer (which is perfectly allowed + * by the standard) and a very small set of wcs-xxx functions provided + * as wrappers around the corresponding str-xxx ones. + * + * Starting with API level 9, wchar_t is properly defined as a 32-bit + * type (as mandated by the compiler itself), and the lines below + * were removed (see $NDK/platforms/android-9/include/sys/cdefs.h). + * + * Note that this only affects C source compilation. For C++, wchar_t + * is a compiler keyboard that cannot be redefined and is always 32-bit. + * + * On the other hand, _WCHAR_IS_8BIT also affects the definition of + * WCHAR_MIN, WCHAR_MAX and WEOF (see <wchar.h> comments). + */ +#ifdef _WCHAR_IS_8BIT #undef __WCHAR_TYPE__ #define __WCHAR_TYPE__ unsigned char - +#endif /* * Macro to test if we're using a GNU C compiler of a specific vintage |