Re: [Qemu-devel] [PATCH] bswap: Don't rely on HOST_LONG_BITS

[Stefan Weil]

Am 30.01.2013 22:04, schrieb Stefan Weil:
> Am 30.01.2013 21:55, schrieb Richard Henderson:
> > This is not always defined in all places qemu/bswap.h is used.
> > If we include qemu-common.h to get it, we create an include loop.
> > This resolves a build problem on any big-endian host like ppc64.
> >
> > Signed-off-by: Richard Henderson<address@hidden>
> > ---
> >   include/qemu/bswap.h | 12 ++++++++++--
> >   1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
> > index e6d4798..d3af35d 100644
> > --- a/include/qemu/bswap.h
> > +++ b/include/qemu/bswap.h
> > @@ -2,8 +2,8 @@
> >   #define BSWAP_H
> >
> >   #include "config-host.h"
> > -
> >   #include<inttypes.h>
> > +#include<limits.h>
> >   #include "fpu/softfloat.h"
> >
> >   #ifdef CONFIG_MACHINE_BSWAP_H
> > @@ -458,7 +458,15 @@ static inline void cpu_to_32wu(uint32_t *p, 
> > uint32_t v)
> >
> >   static inline unsigned long leul_to_cpu(unsigned long v)
> >   {
> > -    return le_bswap(v, HOST_LONG_BITS);
> > +    /* In order to break an include loop between here and
> > +       qemu-common.h, don't rely on HOST_LONG_BITS.  */
> > +#if ULONG_MAX == UINT32_MAX
> > +    return le_bswap(v, 32);
> > +#elif ULONG_MAX == UINT64_MAX
> > +    return le_bswap(v, 64);
> > +#else
> > +# error Unknown sizeof long
> > +#endif
> >   }
> >
> >   #undef le_bswap
>
> That would be wrong for 64 bit MinGW-w64 because
> HOST_LONG_BITS is _not_ the bit size of a long value.
>
> See qemu-common.h for the correct definition.
>
> Regards
> Stefan W.

Could you please try whether this patch fixes the build problems:


From 4dd39af7a3e493669977ec6f50e91bf649b5727f Mon Sep 17 00:00:00 2001
From: Stefan Weil <address@hidden>
Date: Wed, 30 Jan 2013 22:52:12 +0100
Subject: [PATCH] Fix build problems for big endian hosts

Make sure that HOST_LONG_BITS is always defined when qemu/bswap.h
is included.

Signed-off-by: Stefan Weil <address@hidden>
---
 fsdev/virtio-9p-marshal.c |   12 +-----------
 hw/spapr_nvram.c          |    2 ++
 include/qemu/bswap.h      |    4 ++++
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/fsdev/virtio-9p-marshal.c b/fsdev/virtio-9p-marshal.c
index 20f308b..4e634df 100644
--- a/fsdev/virtio-9p-marshal.c
+++ b/fsdev/virtio-9p-marshal.c
@@ -11,20 +11,10 @@
  *
  */

-#include <glib.h>
 #include <glib/gprintf.h>
-#include <sys/types.h>
-#include <dirent.h>
-#include <sys/time.h>
-#include <utime.h>
-#include <sys/uio.h>
-#include <string.h>
-#include <stdint.h>
-#include <errno.h>

-#include "qemu/compiler.h"
+#include "qemu-common.h"
 #include "virtio-9p-marshal.h"
-#include "qemu/bswap.h"

 void v9fs_string_free(V9fsString *str)
 {
diff --git a/hw/spapr_nvram.c b/hw/spapr_nvram.c
index 680cdba..2960b15 100644
--- a/hw/spapr_nvram.c
+++ b/hw/spapr_nvram.c
@@ -22,6 +22,8 @@
  * THE SOFTWARE.
  */

+#include "qemu-common.h"
+
 #include <libfdt.h>

 #include "sysemu/device_tree.h"
diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
index e6d4798..07dadc2 100644
--- a/include/qemu/bswap.h
+++ b/include/qemu/bswap.h
@@ -13,6 +13,10 @@
 #elif defined(CONFIG_BYTESWAP_H)
 # include <byteswap.h>

+#if !defined(HOST_LONG_BITS)
+# error needs HOST_LONG_BITS
+#endif
+
 static inline uint16_t bswap16(uint16_t x)
 {
     return bswap_16(x);
--
1.7.10.4