----- Original Message -----
> From: Paul Durrant <paul.durr...@citrix.com>
> To: Ian Murray <murra...@yahoo.co.uk>; "xen-de...@lists.xensource.com"
> <xen-de...@lists.xensource.com>
> Cc:
> Sent: Monday, 16 March 2015, 9:45
> Subject: Re: [Xen-devel] Compliling Xen 4.5.0 Fails with error:
> ‘bufioreq_pfn’ may be used uninitialised in this function
> [-Werror=uninitialized]
>
>> -----Original Message-----
>> From: xen-devel-boun...@lists.xen.org [mailto:xen-devel-
>> boun...@lists.xen.org] On Behalf Of Ian Murray
>> Sent: 15 March 2015 22:59
>> To: xen-de...@lists.xensource.com
>> Subject: [Xen-devel] Compliling Xen 4.5.0 Fails with error: ‘bufioreq_pfn’
> may
>> be used uninitialised in this function [-Werror=uninitialized]
>>
>> Hi,
>>
>> This was originally posted to the user list but it was suggested to me to
> post it
>> here also. I am getting a failed compilation when I try to compile Xen
> 4.5.0
>> from the tarball and also from Git. I can compile RC4, although a bisect
>> reveals that they pertinent difference is debug=y in Config.mk, which
> allows
>> it to compile. That compiles without a problem and that is what I am
> running
>> with. I have tried to build on two different servers with the same result,
>> however both are running Ubuntu 12.04.5 and are similarly configured.
>>
>> Steps I (would) use to build are simply...
>>
>> ./configure
>> make dist
>> make install
>>
>>
>> which results in...
>>
>> ...
>> gcc -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 -Wall
>> -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-
>> variable
>> -DNDEBUG -I/root/xen450/xen-4.5.0/xen/include
>> -I/root/xen450/xen-4.5.0/xen/include/asm-x86/mach-generic
>> -I/root/xen450/xen-4.5.0/xen/include/asm-x86/mach-default -msoft-float
>> -fno-stack-protector -fno-exceptions -Wnested-externs -DHAVE_GAS_VMX
>> -DHAVE_GAS_EPT -DHAVE_GAS_FSGSBASE -mno-red-zone -mno-sse -fpic
>> -fno-asynchronous-unwind-tables -DGCC_HAS_VISIBILITY_ATTRIBUTE -fno-
>> builtin
>> -fno-common -Werror -Wredundant-decls -Wno-pointer-arith -pipe -g -
>> D__XEN__
>> -include /root/xen450/xen-4.5.0/xen/include/xen/config.h -nostdinc -
>> DHAS_ACPI
>> -DHAS_GDBSX -DHAS_PASSTHROUGH -DHAS_MEM_ACCESS -
>> DHAS_MEM_PAGING
>> -DHAS_MEM_SHARING -DHAS_PCI -DHAS_IOPORTS -DHAS_PDX -MMD -MF
>> .hvm.o.d -c hvm.c
>> -o hvm.o
>> hvm.c: In function ‘hvm_create_ioreq_server’:
>> hvm.c:487:18: error: ‘bufioreq_pfn’ may be used uninitialised in this
> function
>> [-Werror=uninitialized]
>> hvm.c:718:30: note: ‘bufioreq_pfn’ was declared here
>> cc1: all warnings being treated as errors
>> make[5]: *** [hvm.o] Error 1
>>
>> Any suggestions are welcome,
>>
>
> Those line numbers don't work for me. I did a checkout of RELEASE-4.5.0 and,
> whilst bufioreq_pfn is indeed declared on line 718, I see no reference to it
> on
> line 487. Also, if I compile debug=n I see no problem. Is it possible you
> don't have a clean checkout of 4.5.0? What version of gcc are you using?
>
> Paul
>
Thanks for replying.
# gcc --version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
This is both from a brand new clone of Git and also the release tarball. Ian C
has commented elsewhere about what the compiler might be up to, although it's
beyond my knowledge in terms of how "clever" the compiler is being. FWIW, I
couldn't really understand the line numbering, so I looked at the files
themselves and couldn't see a direct, either.... and surely the variable in
question is well out of scope at that point. (obviously I am being naive about
something here.)
>
>> Thanks for reading,
>>
>> Ian.
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xen.org
>> http://lists.xen.org/xen-devel
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