| Summary: | sys-libs/uclibc incorrectly defines bwsap_64(x) to take a long long, causes sys-fs/f2fs-1.6.0 fails to build on big endian systems | ||
|---|---|---|---|
| Product: | Gentoo Linux | Reporter: | Anthony Basile <blueness> |
| Component: | [OLD] Core system | Assignee: | Embedded Gentoo Team <embedded> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | ||
| Priority: | Normal | ||
| Version: | unspecified | ||
| Hardware: | All | ||
| OS: | Linux | ||
| See Also: | https://bugs.gentoo.org/show_bug.cgi?id=577186 | ||
| Whiteboard: | |||
| Package list: | Runtime testing required: | --- | |
| Bug Depends on: | |||
| Bug Blocks: | 570544 | ||
|
Description
Anthony Basile
2016-03-12 18:19:33 UTC
Here's a little piece of code to show what fails
#include <byteswap.h>
int main() {
long long x = 42.0; // works on both glibc and uclibc
//double x = 42.0; // fails on uclibc, works on glibc
bswap_64(x);
}
Note: this only affects f2fs-tools on big endian systems because the same marcos are define in terms of __u32 and __u64 on little endian systems.
If we replace the marco defined in uclibc's /usr/include/bits/byteswap-common.h with the macro from glibc using the definition of __uint64_t from <bits/types.> it fixes the issue. Here's an inline patch just to explain the issue:
--- /usr/include/bits/byteswap-common.h.bak 2016-03-12 18:56:39.812000000 +0000
+++ /usr/include/bits/byteswap-common.h 2016-03-12 19:00:11.512000000 +0000
@@ -85,24 +85,12 @@
| (((x) & 0x000000000000ff00ull) << 40) \
| (((x) & 0x00000000000000ffull) << 56))
-# ifndef __bswap_non_constant_64
-# define __bswap_non_constant_64(x) \
- (__extension__ \
- ({ union { __extension__ unsigned long long int __ll; \
- unsigned int __l[2]; } __w, __r; \
- __w.__ll = (x); \
- __r.__l[0] = __bswap_non_constant_32 (__w.__l[1]); \
- __r.__l[1] = __bswap_non_constant_32 (__w.__l[0]); \
- __r.__ll; }))
-# endif
-# define __bswap_64(x) \
- (__extension__ \
- ({ __extension__ unsigned long long int __ll; \
- if (__builtin_constant_p (x)) \
- __ll = __bswap_constant_64 (x); \
- else \
- __ll = __bswap_non_constant_64 (x); \
- __ll; }))
+#include <bits/types.h>
+static __inline __uint64_t
+__bswap_64 (__uint64_t __bsx)
+{
+ return __bswap_constant_64 (__bsx);
+}
#endif
#endif /* _BITS_BYTESWAP_H */
Looks like we should just reimport byteswap.h + byteswap-16.h from glibc. patches gone upstream(s): https://www.mail-archive.com/uclibc@uclibc.org/msg10483.html and http://mailman.uclibc-ng.org/pipermail/devel/2016-March/000806.html |