[Pkg-xen-devel] Bug#625438: Bug#625438: xen: ftbfs with gcc-4.6 -Werror

[Ian Campbell]

On Tue, 2011-05-03 at 10:34 +0000, Matthias Klose wrote:
> Package: xen
> Version: 4.1.0-3
> Severity: important
> Tags: wheezy sid
> User: debian-gcc at lists.debian.org
> Usertags: ftbfs-gcc-4.6 ftbfs-werror
> 
> This package builds with -Werror, and GCC 4.6 triggers new warnings
> which will make the package fail to build.  Currently a Debian patch
> just passes
>     -Wno-error=unused-but-set-variable and
>     -Wno-error=unused-but-set-parameter
> to avoid build failures, but this patch will be reverted with the
> GCC 4.6.1 release, and the severity of the report will be raised.
> 
> The full build log can be found at:
> http://people.debian.org/~doko/tmp/werror/xen_4.1.0-3_lsid64.buildlog
> The last lines of the build log are at the end of this report.

The build error in that log seems to be:
gcc -g -O2 -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wno-unused-value -Wdeclaration-after-statement  -DNDEBUG -nostdinc -fno-builtin -fno-common -Wredundant-decls -iwithprefix include -Werror -Wno-pointer-arith -pipe -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include  -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm-x86/mach-generic -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm-x86/mach-default -msoft-float -fno-stack-protector -fno-exceptions -mno-red-zone -fpic -fno-asynchronous-unwind-tables -DGCC_HAS_VISIBILITY_ATTRIBUTE -g -D__XEN__ -MMD -MF .xen.d -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wno-unused-value -Wdeclaration-after-statement  -DNDEBUG -nostdinc -fno-builtin -fno-common -Wredundant-decls -iwithprefix include -Werror -Wno-pointer-arith -pipe -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include  -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm-x86/mach-generic -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm-x86/mach-default -msoft-float -fno-stack-protector -fno-exceptions -mno-red-zone -fpic -fno-asynchronous-unwind-tables -DGCC_HAS_VISIBILITY_ATTRIBUTE -g -D__XEN__ -MMD -MF .built_in.o.d -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wno-unused-value -Wdeclaration-after-statement  -DNDEBUG -nostdinc -fno-builtin -fno-common -Wredundant-decls -iwithprefix include -Werror -Wno-pointer-arith -pipe -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include  -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm-x86/mach-generic -I/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm-x86/mach-default -msoft-float -fno-stack-protector -fno-exceptions -mno-red-zone -fpic -fno-asynchronous-unwind-tables -DGCC_HAS_VISIBILITY_ATTRIBUTE -g -D__XEN__ -MMD -MF .io_apic.o.d -c io_apic.c -o io_apic.o
io_apic.c: In function 'restore_IO_APIC_setup':
/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm/io_apic.h:150:26: error: '*((void *)&entry+4)' may be used uninitialized in this function [-Werror=uninitialized]
io_apic.c:221:32: note: '*((void *)&entry+4)' was declared here
/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm/io_apic.h:150:26: error: 'entry' may be used uninitialized in this function [-Werror=uninitialized]
io_apic.c:221:32: note: 'entry' was declared here
cc1: all warnings being treated as errors

which unless I'm mistaken is unrelated to the unused-but-set-variable or
unused-but-set-parameter warnings (although the warning does seem
valid), is this the right log or am I missing something?

Ian.
-- 
Ian Campbell
Current Noise: Enslaved - Havenless

Inspiration without perspiration is usually sterile.