Does anyone know why the following deep voodoo magic in include/cramfs/cramfs_fs.h is needed?
#define CRAMFS_GET_NAMELEN(x) (((u8*)(x))[8] & 0x3f) #define CRAMFS_GET_OFFSET(x) ((CRAMFS_24(((u32*)(x))[2] & 0xffffff) << 2) |\ ((((u32*)(x))[2] & 0xc0000000) >> 30)) #define CRAMFS_SET_NAMELEN(x,y) (((u8*)(x))[8] = (((0x3f & (y))) | \ (0xc0 & ((u8*)(x))[8]))) #define CRAMFS_SET_OFFSET(x,y) (((u32*)(x))[2] = (((y) & 3) << 30) | \ CRAMFS_24((((y) & 0x03ffffff) >> 2)) | \ (((u32)(((u8*)(x))[8] & 0x3f)) << 24))
It looks like a workaround for buggy bitfield handling in the compiler, but newer versions of gcc are not at all happy with it and spews warnings like this:
cramfs.c:82: warning: dereferencing type-punned pointer will break strict-aliasing rules
which indicates that the generated code is probably wrong.
Can we get rid of it somehow?
Haavard