The three patched files use PATH_MAX without defining the required
_POSIX_C_SOURCE feature test macro. This prevents compilation with the
musl libc. The patch applies to 2.6.38.2.
Changes since v1:
- fix scripts/kconfig/lex.zconf.c_shipped
- fix scripts/kconfig/mconf.c
Sorry about the incomplete patch I sent a few hours ago, it won't happen
again. :)
Best regards,
Valentin
Signed-off-by: Valentin Ochs <[email protected]>
---
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -102,7 +102,7 @@
* through arch/um/include/uml-config.h; this fixdep "bug" makes sure that
* those files will have correct dependencies.
*/
+#define _POSIX_C_SOURCE 200809L
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
--- a/scripts/kconfig/lex.zconf.c_shipped
+++ b/scripts/kconfig/lex.zconf.c_shipped
@@ -35,6 +35,7 @@
/* First, we deal with platform-specific or compiler-specific issues. */
/* begin standard C headers. */
+#define _POSIX_C_SOURCE 200809L
#include <stdio.h>
#include <string.h>
#include <errno.h>
--- a/scripts/kconfig/mconf.c
+++ b/scripts/kconfig/mconf.c
@@ -7,7 +7,7 @@
*
* i18n, 2005, Arnaldo Carvalho de Melo <[email protected]>
*/
+#define _POSIX_C_SOURCE 200809L
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
Hi,
On Sat, Apr 9, 2011 at 10:09 PM, Valentin Ochs <[email protected]> wrote:
> The three patched files use PATH_MAX without defining the required
> _POSIX_C_SOURCE feature test macro. ?This prevents compilation with the
> musl libc. ?The patch applies to 2.6.38.2.
>
> Changes since v1:
> ?- fix scripts/kconfig/lex.zconf.c_shipped
this file is autogenerated from zconf.l, which should be updated as
well. I'm not sure how you searched for PATH_MAX, but you're still
missing `confdata.c' and `nconf.c'.
I had a quick look to different libc implementation, glibc and uClibc
default to _POSIX_C_SOURCE == 200112L, FreeBSD >8.0 defaults to
200809L for >8.0, FreeBSD 7.x to 200112L. None of these seems to
requires _POSIX_C_SOURCE to define PATH_MAX, so I'm not certain of the
requirement of the change. Moreover, musl libc seems to be really
young (first public version less than two month old), and still marked
"alpha", not sure if its the best time to start fixing things.
- Arnaud
> ?- fix scripts/kconfig/mconf.c
>
> Sorry about the incomplete patch I sent a few hours ago, it won't happen
> again. :)
>
> Best regards,
> Valentin
>
> Signed-off-by: Valentin Ochs <[email protected]>
> ---
> --- a/scripts/basic/fixdep.c
> +++ b/scripts/basic/fixdep.c
> @@ -102,7 +102,7 @@
> ?* through arch/um/include/uml-config.h; this fixdep "bug" makes sure that
> ?* those files will have correct dependencies.
> ?*/
>
> +#define _POSIX_C_SOURCE 200809L
> ?#include <sys/types.h>
> ?#include <sys/stat.h>
> ?#include <sys/mman.h>
> --- a/scripts/kconfig/lex.zconf.c_shipped
> +++ b/scripts/kconfig/lex.zconf.c_shipped
> @@ -35,6 +35,7 @@
> ?/* First, we deal with ?platform-specific or compiler-specific issues. */
>
> ?/* begin standard C headers. */
> +#define _POSIX_C_SOURCE 200809L
> ?#include <stdio.h>
> ?#include <string.h>
> ?#include <errno.h>
> --- a/scripts/kconfig/mconf.c
> +++ b/scripts/kconfig/mconf.c
> @@ -7,7 +7,7 @@
> ?*
> ?* i18n, 2005, Arnaldo Carvalho de Melo <[email protected]>
> ?*/
>
> +#define _POSIX_C_SOURCE 200809L
> ?#include <ctype.h>
> ?#include <errno.h>
> ?#include <fcntl.h>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in
> the body of a message to [email protected]
> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
>
Thanks for the answer!
On Sat, Apr 09, 2011 at 11:34:00PM -0400, Arnaud Lacombe wrote:
> Hi,
>
> On Sat, Apr 9, 2011 at 10:09 PM, Valentin Ochs <[email protected]> wrote:
> > The three patched files use PATH_MAX without defining the required
> > _POSIX_C_SOURCE feature test macro. This prevents compilation with the
> > musl libc. The patch applies to 2.6.38.2.
> >
> > Changes since v1:
> > - fix scripts/kconfig/lex.zconf.c_shipped
> this file is autogenerated from zconf.l, which should be updated as
> well. I'm not sure how you searched for PATH_MAX, but you're still
> missing `confdata.c' and `nconf.c'.
To be honest, I only fixed the files that did not compile when I ran
'make menuconfig'. It didn't even occur to me that it could be in other
files as well. I've grepped for it now, and there are lots of other
files that use PATH_MAX - it's probably safe to assume that kernel/* and
fs/* use the limits.h in include/linux. What about the files in tools/*?
Would it be preferable to have the makefile define _POSIX_C_SOURCE, or
is that too hackish?
> I had a quick look to different libc implementation, glibc and uClibc
> default to _POSIX_C_SOURCE == 200112L, FreeBSD >8.0 defaults to
> 200809L for >8.0, FreeBSD 7.x to 200112L.
I got the value I used from the Open Group System Interfaces
specification, but the musl author said that 200112L would be fine too.
> None of these seems to requires _POSIX_C_SOURCE to define PATH_MAX, so
> I'm not certain of the requirement of the change.
While I don't want to appear like a language lawyer, the specification
says that 'all symbols required by POSIX.1-2008 to appear when the
header is included shall be made visible' when an application defines
_POSIX_C_SOURCE. I guess the musl author interprets that as 'if you
don't define the feature test macros, you're not getting PATH_MAX.' This
does not seem to be incorrect behaviour to me.
> Moreover, musl libc seems to be really young (first public version
> less than two month old), and still marked "alpha", not sure if its
> the best time to start fixing things.
I don't think that the musl headers are going to change much in that
regard, and the patch only changes the files to better conform to POSIX.
But if you don't want to apply the patch now, I can resubmit it in a
few months and just ask the musl author to put it on the musl website
for now.
Best regards,
Valentin
> - Arnaud
>
> > - fix scripts/kconfig/mconf.c
> >
> > Sorry about the incomplete patch I sent a few hours ago, it won't
> > happen again. :)
On 10.4.2011 16:31, Valentin Ochs wrote:
> On Sat, Apr 09, 2011 at 11:34:00PM -0400, Arnaud Lacombe wrote:
>> On Sat, Apr 9, 2011 at 10:09 PM, Valentin Ochs <[email protected]> wrote:
>>> The three patched files use PATH_MAX without defining the required
>>> _POSIX_C_SOURCE feature test macro. This prevents compilation with the
>>> musl libc. The patch applies to 2.6.38.2.
>>>
>>> Changes since v1:
>>> - fix scripts/kconfig/lex.zconf.c_shipped
>> this file is autogenerated from zconf.l, which should be updated as
>> well. I'm not sure how you searched for PATH_MAX, but you're still
>> missing `confdata.c' and `nconf.c'.
Yes, please fix the bison parser and run make GENERATE_PARSER=1
menuconfig to update the *_shipped files.
>> I had a quick look to different libc implementation, glibc and uClibc
>> default to _POSIX_C_SOURCE == 200112L, FreeBSD >8.0 defaults to
>> 200809L for >8.0, FreeBSD 7.x to 200112L.
>
> I got the value I used from the Open Group System Interfaces
> specification, but the musl author said that 200112L would be fine too.
I suggest you use 200112L, so that it is a nop for glibc/uClibc builds.
Please also accompany it with a /* for PATH_MAX */ comment or so.
>
>> None of these seems to requires _POSIX_C_SOURCE to define PATH_MAX, so
>> I'm not certain of the requirement of the change.
>
> While I don't want to appear like a language lawyer, the specification
> says that 'all symbols required by POSIX.1-2008 to appear when the
> header is included shall be made visible' when an application defines
> _POSIX_C_SOURCE. I guess the musl author interprets that as 'if you
> don't define the feature test macros, you're not getting PATH_MAX.' This
> does not seem to be incorrect behaviour to me.
While I don't completely understand the motivation for such
super-pedantic libc implementation, the fact is that POSIX says one
should define this macro, so let's define it, it does not hurt us.
Michal
Hi,
On Tue, Apr 19, 2011 at 5:54 AM, Michal Marek <[email protected]> wrote:
> On 10.4.2011 16:31, Valentin Ochs wrote:
>> On Sat, Apr 09, 2011 at 11:34:00PM -0400, Arnaud Lacombe wrote:
>>> On Sat, Apr 9, 2011 at 10:09 PM, Valentin Ochs <[email protected]> wrote:
>>>> The three patched files use PATH_MAX without defining the required
>>>> _POSIX_C_SOURCE feature test macro. ?This prevents compilation with the
>>>> musl libc. ?The patch applies to 2.6.38.2.
>>>>
>>>> Changes since v1:
>>>> ?- fix scripts/kconfig/lex.zconf.c_shipped
>>> this file is autogenerated from zconf.l, which should be updated as
>>> well. I'm not sure how you searched for PATH_MAX, but you're still
>>> missing `confdata.c' and `nconf.c'.
>
> Yes, please fix the bison parser and run make GENERATE_PARSER=1
> menuconfig to update the *_shipped files.
>
>
>>> I had a quick look to different libc implementation, glibc and uClibc
>>> default to _POSIX_C_SOURCE == 200112L, FreeBSD >8.0 defaults to
>>> 200809L for >8.0, FreeBSD 7.x to 200112L.
>>
>> I got the value I used from the Open Group System Interfaces
>> specification, but the musl author said that 200112L would be fine too.
>
> I suggest you use 200112L, so that it is a nop for glibc/uClibc builds.
> Please also accompany it with a /* for PATH_MAX */ comment or so.
>
no it's not. Defining _POSIX_C_SOURCE disables automatic definition of
a few features macros, see below.
>>
>>> None of these seems to requires _POSIX_C_SOURCE to define PATH_MAX, so
>>> I'm not certain of the requirement of the change.
>>
>> While I don't want to appear like a language lawyer, the specification
>> says that 'all symbols required by POSIX.1-2008 to appear when the
>> header is included shall be made visible' when an application defines
>> _POSIX_C_SOURCE. I guess the musl author interprets that as 'if you
>> don't define the feature test macros, you're not getting PATH_MAX.' This
>> does not seem to be incorrect behaviour to me.
>
> While I don't completely understand the motivation for such
> super-pedantic libc implementation, the fact is that POSIX says one
> should define this macro, so let's define it, it does not hurt us.
>
If we go that way, we should at least:
diff --git a/Makefile b/Makefile
index d6592b6..0490413 100644
--- a/Makefile
+++ b/Makefile
@@ -233,7 +233,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then
echo $$BASH; \
HOSTCC = gcc
HOSTCXX = g++
-HOSTCFLAGS = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2
-fomit-frame-pointer
+HOSTCFLAGS = -D_POSIX_C_SOURCE=200112L -Wall -Wmissing-prototypes
-Wstrict-prototypes -O2 -fomit-frame-pointer
HOSTCXXFLAGS = -O2
at best:
index d6592b6..0490413 100644
--- a/Makefile
+++ b/Makefile
@@ -233,7 +233,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then
echo $$BASH; \
HOSTCC = gcc
HOSTCXX = g++
-HOSTCFLAGS = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2
-fomit-frame-pointer
+HOSTCFLAGS = --std=c99 -D_POSIX_C_SOURCE=200112L -Wall
-Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
HOSTCXXFLAGS = -O2
Both introduces new warnings with the glibc shipped with fedora 14
relating to strdup(3) needing one of: _SVID_SOURCE, _BSD_SOURCE,
_XOPEN_SOURCE, _POSIX_C_SOURCE>=200809L (for __USE_XOPEN2K8).
-D_POSIX_C_SOURCE=200809L do not generate more warning, at least on my
host.
Just for reference, the second change fails anyway as `nconf' uses GNU
extension of C99.
- Arnaud
> Michal
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in
> the body of a message to [email protected]
> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
>
Hi,
On Tue, Apr 19, 2011 at 1:03 PM, Arnaud Lacombe <[email protected]> wrote:
> diff --git a/Makefile b/Makefile
> index d6592b6..0490413 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -233,7 +233,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then
> echo $$BASH; \
>
> ?HOSTCC ? ? ? = gcc
> ?HOSTCXX ? ? ?= g++
> -HOSTCFLAGS ? = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2
> -fomit-frame-pointer
> +HOSTCFLAGS ? = -D_POSIX_C_SOURCE=200112L -Wall -Wmissing-prototypes
> -Wstrict-prototypes -O2 -fomit-frame-pointer
> ?HOSTCXXFLAGS = -O2
>
Sorry, gmail wrapped long lines, the relevant part is only:
HOSTCFLAGS+= -D_POSIX_C_SOURCE=200112L
- Arnaud