From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Egger Subject: Re: [PATCH] xen: Deal with stdarg.h and -nostdinc Date: Fri, 27 May 2011 09:55:59 +0200 Message-ID: <4DDF590F.5040706@amd.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" , Ian Jackson List-Id: xen-devel@lists.xenproject.org On 05/26/11 19:08, Keir Fraser wrote: > On 26/05/2011 17:11, "Ian Jackson" wrote: > >> Christoph Egger writes ("[Xen-devel] [PATCH] xen: Deal with stdarg.h and >> -nostdinc"): >>> For compiling the xen kernel we use -nostdinc which means >>> we don't want to rely on any external headers. >>> That also counts vor stdarg.h. >> >> Right, OK, but: > > Not really. We are only doing the same as Linux right now. I do note that > they add an -isystem option to their command line, with a gcc include path > that they presumably dump out of gcc in some standard way. However, our > current approach seems to work, if it fails to work in some situation it is > likely to be pretty obvious (build or link failure), and we can fix it then. The cross-compiling facility in NetBSD has been further improved which made gcc more pendantic for this. -nostdinc is used and -isystem is *not* used. > This stuff can be moderately fragile, and we've now had no actual bug > reports about it in a long while. Here is a full error message: gcc -O2 -I/usr/include -I/usr/pkg/include -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wno-unused-value -Wdeclaration-after-statement -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wno-unused-value -Wdeclaration-after-statement -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/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include -I/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/asm-x86/mach-generic -I/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/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/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include -I/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/asm-x86/mach-generic -I/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/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 .asm-offsets.s.d -S -o asm-offsets.s x86_64/asm-offsets.c In file included from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/lib.h:5, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/asm/system.h:4, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/spinlock.h:5, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/sched.h:7, from x86_64/asm-offsets.c:10: /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/stdarg.h:4:22: error: stdarg.h: No such file or directory In file included from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/asm/system.h:4, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/spinlock.h:5, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/sched.h:7, from x86_64/asm-offsets.c:10: /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/lib.h:86: error: expected declaration specifiers or '...' before 'va_list' /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/lib.h:90: error: expected declaration specifiers or '...' before 'va_list' /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/lib.h:94: error: expected declaration specifiers or '...' before 'va_list' In file included from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/acpi/acpi.h:61, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/xen/acpi.h:34, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/acpi/apei.h:8, from /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/asm/fixmap.h:23, from x86_64/asm-offsets.c:12: /tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/include/acpi/acpiosxf.h:257: error: expected declaration specifiers or '...' before 'va_list' gmake[3]: *** [asm-offsets.s] Error 1 gmake[3]: Leaving directory `/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/arch/x86' gmake[2]: *** [/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen/xen] Error 2 gmake[2]: Leaving directory `/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen' gmake[1]: *** [install] Error 2 gmake[1]: Leaving directory `/tmp/pkgsrc-obj/sysutils/xenkernel41/work.ixp/xen-4.1.0/xen' > > -- Keir > >>> Use the external header when we compile the tools. >>> Adapt libelf-loader.c which is compiled in the kernel >>> and with the tools. >> >> -#include >> +#include "../../include/xen/stdarg.h" >> >> Firstly, is this correct for all uses of libelf-loader ? This file is >> compiled both for use inside Xen and for use on the host. In the >> latter case it /should/ use the system's stdarg.h. >> >> Also, this kind of relative path should not be necessary. The >> relevant files should be on the include path. >> >> So I think this should be fixed by arranging that your new stdarg.h is >> on the relevant include path, not by changing the .c file. >> >> Ian. >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xensource.com >> http://lists.xensource.com/xen-devel > > > -- ---to satisfy European Law for business letters: Advanced Micro Devices GmbH Einsteinring 24, 85689 Dornach b. Muenchen Geschaeftsfuehrer: Alberto Bozzo, Andrew Bowd Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632