On Tuesday, 28 April 2015, at 9:56 am, Rich Felker wrote: > What I do think is a bad idea is providing a hackish environment where > only some things work correctly with 64-bit off_t and others silently > fail or even misinterpret their arguments and blow up. If that can be > avoided and the ugliness can be contained in a pit that's isolated to > Bionic, I'm not opposed to it.
For what it's worth, BusyBox *presently* misinterprets arguments on Bionic because Bionic's struct stat has 64-bit st_ino and st_size, but BusyBox happily assigns the values of these fields into variables of type ino_t and off_t, which breaks at run-time. These problems would be apparent at compile-time too, except that BusyBox's build system doesn't specify -Wconversion, so no warnings are produced. Specifying -Wconversion reveals numerous places throughout the BusyBox sources where rvalues are implicitly narrowed. My personal belief is that these warnings should always be enabled, and implicit narrowing conversions should always be avoided by using explicit casts, to make obvious that a change in value is possible, but I am not here to convince the BusyBox devs to eliminate all the implicit narrowing conversions in BusyBox. Besides, I agree that Bionic is at fault for deviating from the standard here by declaring st_ino and st_size as unsigned long long and long long rather than as ino_t and off_t. I'll work on finishing the Large File Support in Bionic and adding support for _FILE_OFFSET_BITS==64. Is there any chance that a Bionic headers patch could be shipped with BusyBox? Again, there is no reason to require BusyBox users to compile against the latest Bionic headers just to get support for large files. In fact, LFS could be implemented on all versions of Bionic with a simple "-include" in CFLAGS. (That's almost no different than implementing it in platform.h, but maybe you'd like it better in a separate file.) _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox
