From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olivier MATZ Subject: Re: Compiling files with .S with GCC Date: Mon, 04 May 2015 17:42:02 +0200 Message-ID: <5547934A.7050600@6wind.com> References: <55472FE0.6010201@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable To: "Wiles, Keith" , "dev-VfR2kkLFssw@public.gmane.org" Return-path: In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On 05/04/2015 04:49 PM, Wiles, Keith wrote: >=20 >=20 > On 5/4/15, 1:37 AM, "Olivier MATZ" wrote: >=20 >> Hello, >> >> On 04/26/2015 06:55 PM, Wiles, Keith wrote: >>> >>> >>> On 4/26/15, 11:53 AM, "Wiles, Keith" wrote: >>> >>>> Hi All, >>>> >>>> I noticed in my builds with foo.S file I would get a warning from th= e >>>> compiler the foo_s.o.tmp linker file will not be used as the code is >>>> not >>>> linked. A strange error and the foo_s.o file would not be created. I= n >>>> the >>>> mk/internal/rte.compile-pre.mk we have the following >>>> >>>> # command to assemble a .S file to generate an object >>>> ifeq ($(USE_HOST),1) >>>> S_TO_O =3D $(CPP) $(HOST_CPPFLAGS) $($(@)_CPPFLAGS) >>>> $(HOST_EXTRA_CPPFLAGS) >>>> $< $(@).tmp && \ >>>> $(HOSTAS) $(HOST_ASFLAGS) $($(@)_ASFLAGS) $(HOST_EXTRA_ASFLAGS) -= o >>>> $@ >>>> $(@).tmp >>>> S_TO_O_STR =3D $(subst ','\'',$(S_TO_O)) #'# fix syntax highlight >>>> S_TO_O_DISP =3D $(if $(V),"$(S_TO_O_STR)"," HOSTAS $(@)") >>>> else >>>> S_TO_O =3D $(CPP) $(CPPFLAGS) $($(@)_CPPFLAGS) $(EXTRA_CPPFLAGS) $< = -o >>>> $(@).tmp && \ >>>> $(AS) $(ASFLAGS) $($(@)_ASFLAGS) $(EXTRA_ASFLAGS) -o $@ $(@).tmp >>>> S_TO_O_STR =3D $(subst ','\'',$(S_TO_O)) #'# fix syntax highlight >>>> S_TO_O_DISP =3D $(if $(V),"$(S_TO_O_STR)"," AS $(@)") >>>> endif >>>> >>>> I had to change the above =C5=92.tmp=C2=B9 strings to =C5=92.s=C2=B9= to remove this warning >>>> and get the foo_s.o file created. Using the .s the file name becomes >>>> foo_s.o.s >>> >>> Compiler used on Ubuntu 14.04 'gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2' >>> >>>> >>>> Did not try this with clang or any other compiler, but I expect we c= an >>>> safely change the =C5=92.tmp=C2=B9 to =C5=92.s=C2=B9 IMO >>>> >>>> Anyone else notice this problem? >> >> I tested a similar use-case and I don't reproduce the issue. >> I don't don't understand why replacing $(@).tmp by $(@).s would >> solve it. >=20 > In the case I saw the compiler seemed to want the .s to under stand it = was > not some other type of file. Not sure why the error occurred in my > external build. We can leave it using .tmp if you like, but I feel .s > would have been the correct name for the file. Can you send a log of the error you've seen? Can you reproduce it outside the dpdk framework by trying to assemble a file called foo.tmp? This would show that the problem really comes from the extension of the file. >=20 > If you think it needs to be changed to .s then you can submit a patch o= r I > can or just leave it along your option. Until we really understand the cause of the issue, I don't think this should be changed. But I'm not opposed to change it if we have a good justification. Regards, Olivier >=20 > Regards, > ++Keith >> >> The file $(@).tmp is used as a temporary file to store the preprocesse= d >> version of the $(@).s file. I agree that using the .s extension is not >> a bad choice (see below), but to me it is not the proper solution to >> your problem. >> >>>From https://gcc.gnu.org/onlinedocs/gcc/Overall-Options.html >> >> file.s >> Assembler code. >> file.S >> file.sx >> Assembler code that must be preprocessed. >> >> Regards, >> Olivier >=20