On Thu, Mar 09, 2017 at 11:52:17AM +1100, Alexey Kardashevskiy wrote: > On 09/03/17 01:21, Peter Maydell wrote: > > On 8 March 2017 at 13:49, Alexey Kardashevskiy <a...@ozlabs.ru> wrote: > >> After 6e85fce0225f "dtc: Update requirement to v1.4.2" QEMU stopped > >> compiling in CentOS7: > >> > >> In file included from /home/aik/p/qemu/dtc/libfdt/libfdt.h:54:0, > >> from /home/aik/p/qemu/device_tree.c:30: > >> /home/aik/p/qemu/dtc/libfdt/libfdt_env.h:64:0: error: "__bitwise" > >> redefined [-Werror] > >> #define __bitwise > >> ^ > >> In file included from /usr/include/asm/ptrace.h:27:0, > >> from /usr/include/asm/sigcontext.h:11, > >> from /usr/include/bits/sigcontext.h:27, > >> from /usr/include/signal.h:340, > >> from /home/aik/p/qemu/include/qemu/osdep.h:86, > >> from /home/aik/p/qemu/device_tree.c:14: > >> /usr/include/linux/types.h:21:0: note: this is the location of the > >> previous definition > >> #define __bitwise __bitwise__ > >> ^ > >> cc1: all warnings being treated as errors > >> make: *** [device_tree.o] Error 1 > >> make: *** Waiting for unfinished jobs.... > >> > >> The reason is that CentOS7 comes with libfdt 1.4.0 so QEMU tries using > >> the internal one which does not compile as CentOS7 comes with gcc v4.8.5 > >> which reports warnings which it would not if the OS's libfdt was used > >> (libfdt_env.h has not changed between 1.4.0 and 1.4.2). > >> > >> gcc 6.2.0 from Ubuntu v16.10 handles this fine. > >> > >> This replaces -I with -isystem to suppress the warning (which turns > >> to an error because of -Werror). > > > > Thanks for the bug report. I think it would be cleaner to fix this > > Agree. > > > by fixing the problem upstream in libfdt and then moving our > > submodule forward to the fixed version. (libfdt should not be > > defining __ prefixed symbols as these are reserved for the > > system.)
Yes. I've now fixed this in upstream libfdt, at Paolo's suggestion.
Unfortunately, it came just after the 1.4.3 release. I was just leery
about making a new release and qemu pull so soon after the last one.
Should I do that anyway?
> Also agree, regardless my proposal, libfdt should be fixed. However v2.9
> won't compile on CentOS7 (and I suppose on RHEL7) which is a bit annoying.
> And having "-isystem" makes some sense as these headers are normally system
> ones and I'd think they should be treated the same way (i.e. path should be
> included via -isystem vs. -I).
I'm not really clear on why -isystem fixes this problem anyway.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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