Re: [PATCH] Use -mx32 for _{POSIX_V7|_POSIX_V6|XBS5}_ILP32_OFFBIG

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Mon, Jun 4, 2012 at 1:59 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Mon, Jun 4, 2012 at 12:48 PM, Roland McGrath <roland@hack.frob.com> wrote:
>> This is a regression for an -m32 build, where ILP32_OFFBIG will no
>> longer be offered. ?That is unacceptable. ?This whole area is subtle
>> and nonobvious, because it's a header in one build environment talking
>> about what other build environments are available.
>>
>> If a user program is using confstr itself, and that program is built
>> with -mx32, then it recommending -mx32 makes some sense. ?But having
>> which environment the installed getconf binary was built for affect
>> what it reports to scripts is much more questionable.
>>
>> I think we need to leave this alone for now, file a bug to track the
>> issue, and consider it further after 2.16.
>>
>
> I opened:
>
> http://sourceware.org/bugzilla/show_bug.cgi?id=14200
>
> One possible solution:
>
> 1. -mx32 build provides POSIX_V6_ILP32_OFFBIG,
> POSIX_V7_ILP32_OFFBIG and XBS5_ILP32_OFFBIG.
> 2. -m32 build provides POSIX_V6_ILP32_OFF32,
> POSIX_V7_ILP32_OFF32, XBS5_ILP32_OFF32,
> POSIX_V6_ILP32_OFFBIG, POSIX_V7_ILP32_OFFBIG
> and XBS5_ILP32_OFFBIG.
>
> If x32 glibc is installed, ia32 glibc won't install
> the ia32 version of POSIX_V6_ILP32_OFFBIG,
> POSIX_V7_ILP32_OFFBIG and XBS5_ILP32_OFFBIG.
>
>

Here is the patch to implement it.  There is no difference
in -m32 build and -mx32 build gets -mx32 for
_{POSIX_V7|_POSIX_V6|XBS5}_ILP32_OFFBIG/

OK for trunk after 2.16 is branched?

Thanks.

-- 
H.J.
----
	[BZ #14200]
	* sysdeps/unix/sysv/linux/x86/bits/environments.h
	(_POSIX_V7_ILP32_OFF32): Defined as 1 only if __x86_64__ isn't
	defined.
	(_POSIX_V6_ILP32_OFF32): Likewise.
	(_XBS5_ILP32_OFF32): Likewise.
	(__ILP32_OFFBIG_CFLAGS): Defined as "-mx32" for x32.
	(__ILP32_OFFBIG_LDFLAGS): Likewise.

diff --git a/sysdeps/unix/sysv/linux/x86/bits/environments.h b/sysdeps/unix/sysv
/linux/x86/bits/environments.h
index 793a04f..8ebc837 100644
--- a/sysdeps/unix/sysv/linux/x86/bits/environments.h
+++ b/sysdeps/unix/sysv/linux/x86/bits/environments.h
@@ -64,15 +64,19 @@

 #else /* __WORDSIZE == 32 */

-/* By default we have 32-bit wide `int', `long int', pointers and `off_t'
-   and all platforms support LFS.  */
-# define _POSIX_V7_ILP32_OFF32	1
+/* We have 32-bit wide `int', `long int' and pointers and all platforms
+   support LFS.  -mx32 has 64-bit wide `off_t'.  */
 # define _POSIX_V7_ILP32_OFFBIG	1
-# define _POSIX_V6_ILP32_OFF32	1
-# define _POSIX_V6_ILP32_OFFBIG	1
-# define _XBS5_ILP32_OFF32	1
+# define _POSIX_V6_ILP32_OFFBIG 1
 # define _XBS5_ILP32_OFFBIG	1

+# ifndef __x86_64__
+/* -m32 has 32-bit wide `off_t'.  */
+#  define _POSIX_V7_ILP32_OFF32	1
+#  define _POSIX_V6_ILP32_OFF32	1
+#  define _XBS5_ILP32_OFF32	1
+# endif
+
 /* We optionally provide an environment with the above size but an 64-bit
    side `off_t'.  Therefore we don't define _POSIX_V7_ILP32_OFFBIG.  */

@@ -89,8 +93,13 @@
 #endif /* __WORDSIZE == 32 */

 #define __ILP32_OFF32_CFLAGS	"-m32"
-#define __ILP32_OFFBIG_CFLAGS	"-m32 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
"
 #define __ILP32_OFF32_LDFLAGS	"-m32"
-#define __ILP32_OFFBIG_LDFLAGS	"-m32"
+#if defined __x86_64__ && defined __ILP32__
+# define __ILP32_OFFBIG_CFLAGS	"-mx32"
+# define __ILP32_OFFBIG_LDFLAGS	"-mx32"
+#else
+# define __ILP32_OFFBIG_CFLAGS	"-m32 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
"
+# define __ILP32_OFFBIG_LDFLAGS	"-m32"
+#endif
 #define __LP64_OFF64_CFLAGS	"-m64"
 #define __LP64_OFF64_LDFLAGS	"-m64"
-- 
1.7.6.5