[PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Andrew Cooper]

c/s 6276f66ebe "libxl: libxl_uuid_copy now takes a ctx argument" introduces
API compatibiltiy for libxl_uuid_copy() which sadly is not valid C.  Fix it.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl_uuid.h |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/libxl/libxl_uuid.h b/tools/libxl/libxl_uuid.h
index 196b5bc..c5041c7 100644
--- a/tools/libxl/libxl_uuid.h
+++ b/tools/libxl/libxl_uuid.h
@@ -61,7 +61,12 @@ int libxl_uuid_from_string(libxl_uuid *uuid, const char *in);
 void libxl_uuid_copy(libxl_ctx *ctx_opt, libxl_uuid *dst,
                      const libxl_uuid *src);
 #if defined(LIBXL_API_VERSION) && LIBXL_API_VERSION < 0x040500
-void libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
+void static inline libxl_uuid_copy_0x040400(libxl_uuid *dst,
+                                            const libxl_uuid *src)
+{
+    libxl_uuid_copy(NULL, dst, src);
+}
+#define libxl_uuid_copy libxl_uuid_copy_0x040400
 #endif
 
 void libxl_uuid_clear(libxl_uuid *uuid);
-- 
1.7.10.4

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Wei Liu]

On Fri, Oct 17, 2014 at 09:56:19AM +0100, Andrew Cooper wrote:
> c/s 6276f66ebe "libxl: libxl_uuid_copy now takes a ctx argument" introduces
> API compatibiltiy for libxl_uuid_copy() which sadly is not valid C.  Fix it.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: Ian Campbell <Ian.Campbell@citrix.com>
> CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
> CC: Wei Liu <wei.liu2@citrix.com>

Acked-by: Wei Liu <wei.liu2@citrix.com>

> ---
>  tools/libxl/libxl_uuid.h |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/libxl/libxl_uuid.h b/tools/libxl/libxl_uuid.h
> index 196b5bc..c5041c7 100644
> --- a/tools/libxl/libxl_uuid.h
> +++ b/tools/libxl/libxl_uuid.h
> @@ -61,7 +61,12 @@ int libxl_uuid_from_string(libxl_uuid *uuid, const char *in);
>  void libxl_uuid_copy(libxl_ctx *ctx_opt, libxl_uuid *dst,
>                       const libxl_uuid *src);
>  #if defined(LIBXL_API_VERSION) && LIBXL_API_VERSION < 0x040500
> -void libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
> +void static inline libxl_uuid_copy_0x040400(libxl_uuid *dst,
> +                                            const libxl_uuid *src)
> +{
> +    libxl_uuid_copy(NULL, dst, src);
> +}
> +#define libxl_uuid_copy libxl_uuid_copy_0x040400
>  #endif
>  
>  void libxl_uuid_clear(libxl_uuid *uuid);
> -- 
> 1.7.10.4

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Ian Jackson]

Andrew Cooper writes ("[PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
> c/s 6276f66ebe "libxl: libxl_uuid_copy now takes a ctx argument" introduces
> API compatibiltiy for libxl_uuid_copy() which sadly is not valid C.  Fix it.
...
>  #if defined(LIBXL_API_VERSION) && LIBXL_API_VERSION < 0x040500
> -void libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)

I think this was intended to read
  #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
but should in fact read
  #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))

I don't understand why you want to introduce a function as well as a
macro.

Ian.

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Andrew Cooper]

On 17/10/14 12:00, Ian Jackson wrote:
> Andrew Cooper writes ("[PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
>> c/s 6276f66ebe "libxl: libxl_uuid_copy now takes a ctx argument" introduces
>> API compatibiltiy for libxl_uuid_copy() which sadly is not valid C.  Fix it.
> ...
>>  #if defined(LIBXL_API_VERSION) && LIBXL_API_VERSION < 0x040500
>> -void libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
> I think this was intended to read
>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
> but should in fact read
>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))

Does this even work?

Won't the parser complain about passing 3 parameters to a two-parameter
macro?

~Andrew

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Ian Jackson]

Andrew Cooper writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
> On 17/10/14 12:00, Ian Jackson wrote:
> > I think this was intended to read
> >   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
> > but should in fact read
> >   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))
> 
> Does this even work?
> 
> Won't the parser complain about passing 3 parameters to a two-parameter
> macro?

mariner:~> ed t.c
t.c: No such file or directory
a
#define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))
libxl_uuid_copy(1,2)
.
w
91
q
mariner:~> gcc -E t.c
# 1 "t.c"
# 1 "<command-line>"
# 1 "t.c"

libxl_uuid_copy(NULL, (1), (2))
mariner:~>

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Ian Jackson]

Ian Jackson writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
> Andrew Cooper writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
> > On 17/10/14 12:00, Ian Jackson wrote:
> > > I think this was intended to read
> > >   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
> > > but should in fact read
> > >   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))

Having checked the rules, for C++ this might conceivably have to be
    #define libxl_uuid_copy(dst, src) (libxl_uuid_copy(NULL, (dst), (src)))

Ian.

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Andrew Cooper]

On 17/10/14 12:08, Ian Jackson wrote:
> Ian Jackson writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
>> Andrew Cooper writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
>>> On 17/10/14 12:00, Ian Jackson wrote:
>>>> I think this was intended to read
>>>>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
>>>> but should in fact read
>>>>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))
> Having checked the rules, for C++ this might conceivably have to be
>     #define libxl_uuid_copy(dst, src) (libxl_uuid_copy(NULL, (dst), (src)))
>
> Ian.

Fundamentally, I am not really fussed how this is fixed, although I have
confirmed my patch fixes the libvirt build in the XenServer branch I am
attempting to test Xen-4.5 under.

~Andrew

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Ian Campbell]

On Fri, 2014-10-17 at 15:19 +0100, Andrew Cooper wrote:
> On 17/10/14 12:08, Ian Jackson wrote:
> > Ian Jackson writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
> >> Andrew Cooper writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
> >>> On 17/10/14 12:00, Ian Jackson wrote:
> >>>> I think this was intended to read
> >>>>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
> >>>> but should in fact read
> >>>>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))
> > Having checked the rules, for C++ this might conceivably have to be
> >     #define libxl_uuid_copy(dst, src) (libxl_uuid_copy(NULL, (dst), (src)))
> >
> > Ian.
> 
> Fundamentally, I am not really fussed how this is fixed, although I have
> confirmed my patch fixes the libvirt build in the XenServer branch I am
> attempting to test Xen-4.5 under.

Ian, are you happy with that or do you want to (ask Andy to) resubmit
with the #define?

Ian.

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Andrew Cooper]

On 20/10/14 15:46, Ian Campbell wrote:
> On Fri, 2014-10-17 at 15:19 +0100, Andrew Cooper wrote:
>> On 17/10/14 12:08, Ian Jackson wrote:
>>> Ian Jackson writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
>>>> Andrew Cooper writes ("Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500"):
>>>>> On 17/10/14 12:00, Ian Jackson wrote:
>>>>>> I think this was intended to read
>>>>>>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, dst, src)
>>>>>> but should in fact read
>>>>>>   #define libxl_uuid_copy(dst, src) libxl_uuid_copy(NULL, (dst), (src))
>>> Having checked the rules, for C++ this might conceivably have to be
>>>     #define libxl_uuid_copy(dst, src) (libxl_uuid_copy(NULL, (dst), (src)))
>>>
>>> Ian.
>> Fundamentally, I am not really fussed how this is fixed, although I have
>> confirmed my patch fixes the libvirt build in the XenServer branch I am
>> attempting to test Xen-4.5 under.
> Ian, are you happy with that or do you want to (ask Andy to) resubmit
> with the #define?
>
> Ian.
>

Ping (regarding question)? Whichever fix gets used eventually. this
really needs to get in before the release candidate is cut.

~Andrew

Re: [PATCH for-4.5] tools/libxl: Fix building against libxl for LIBXL_API_VERSION < 0x040500

[Ian Campbell]

On Thu, 2014-10-23 at 13:19 +0100, Andrew Cooper wrote:
> Ping (regarding question)? Whichever fix gets used eventually. this
> really needs to get in before the release candidate is cut.

I've applied it locally and kicked off my usual set of tests, I'll push
once those complete (and/or I've finished lunch, whichever comes second)
unless Ian objects before then.

Ian.