[PATCH] xenctrl: Make the headers C++ friendly

[PATCH] xenctrl: Make the headers C++ friendly

[Razvan Cojocaru]

Moved an enum definition before the typedef that uses it.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
 tools/libxc/xenctrl.h |   19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index af6f249..abd8947 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -119,6 +119,16 @@ typedef struct xc_interface_core xc_interface;
 typedef struct xc_interface_core xc_evtchn;
 typedef struct xc_interface_core xc_gnttab;
 typedef struct xc_interface_core xc_gntshr;
+
+enum xc_error_code {
+  XC_ERROR_NONE = 0,
+  XC_INTERNAL_ERROR = 1,
+  XC_INVALID_KERNEL = 2,
+  XC_INVALID_PARAM = 3,
+  XC_OUT_OF_MEMORY = 4,
+  /* new codes need to be added to xc_error_level_to_desc too */
+};
+
 typedef enum xc_error_code xc_error_code;
 
 
@@ -1766,15 +1776,6 @@ int xc_hvm_inject_trap(
  */
 
 
-enum xc_error_code {
-  XC_ERROR_NONE = 0,
-  XC_INTERNAL_ERROR = 1,
-  XC_INVALID_KERNEL = 2,
-  XC_INVALID_PARAM = 3,
-  XC_OUT_OF_MEMORY = 4,
-  /* new codes need to be added to xc_error_level_to_desc too */
-};
-
 #define XC_MAX_ERROR_MSG_LEN 1024
 typedef struct xc_error {
   enum xc_error_code code;
-- 
1.7.9.5

Re: [PATCH] xenctrl: Make the headers C++ friendly

[George Dunlap]

On Wed, Jul 2, 2014 at 5:30 PM, Razvan Cojocaru
<rcojocaru@bitdefender.com> wrote:
> Moved an enum definition before the typedef that uses it.

Presumably you want this because you have an out-of-tree program that
you want to compile against libxc.  You do realize that libxc isn't a
stable API, right?  That it may change in incompatible ways in every
release?

I presume you'd rather use a stable API -- in which case maybe we
should ask what it is your application needs, and we can try to come
up with a way to support you.  (Perhaps by declaring certain parts of
the libxc interface as "stable", if libxl isn't suitable for some
reason.)

 -George

Re: [PATCH] xenctrl: Make the headers C++ friendly

[Razvan Cojocaru]

On 07/03/2014 01:56 PM, George Dunlap wrote:
> On Wed, Jul 2, 2014 at 5:30 PM, Razvan Cojocaru
> <rcojocaru@bitdefender.com> wrote:
>> Moved an enum definition before the typedef that uses it.
> 
> Presumably you want this because you have an out-of-tree program that
> you want to compile against libxc.  You do realize that libxc isn't a
> stable API, right?  That it may change in incompatible ways in every
> release?

Yes, I've glimpsed into that by following it since Xen 4.1.
I am indeed compiling an application against libxc.

> I presume you'd rather use a stable API -- in which case maybe we
> should ask what it is your application needs, and we can try to come
> up with a way to support you.  (Perhaps by declaring certain parts of
> the libxc interface as "stable", if libxl isn't suitable for some
> reason.)

Thanks, that's a very gracious offer. Well, here's what nm has to say
about what I'm using from the Xen libraries:

xc_copy_to_domain_page
xc_domain_decrease_reservation_exact
xc_domain_get_tsc_info
xc_domain_getinfo
xc_domain_hvm_getcontext_partial
xc_domain_pause
xc_domain_populate_physmap_exact
xc_domain_set_access_required
xc_domain_set_pagefault_info
xc_domain_shutdown
xc_domain_unpause
xc_evtchn_bind_interdomain
xc_evtchn_close
xc_evtchn_fd
xc_evtchn_notify
xc_evtchn_open
xc_evtchn_pending
xc_evtchn_unbind
xc_evtchn_unmask
xc_get_hvm_param
xc_get_mem_access
xc_interface_close
xc_interface_open
xc_map_foreign_batch
xc_map_foreign_range
xc_mem_access_disable
xc_mem_access_enable
xc_mem_access_resume
xc_set_hvm_param
xc_set_mem_access
xc_translate_foreign_address
xc_vcpu_getcontext
xc_vcpu_setcontext
xc_version
xs_close
xs_directory
xs_fileno
xs_is_domain_introduced
xs_open
xs_read
xs_read_watch
xs_unwatch
xs_watch

Libxl is, unfortunately, too high-level for our needs.


Thanks,
Razvan Cojocaru

Re: [PATCH] xenctrl: Make the headers C++ friendly

[Slutz, Donald Christopher]

On 07/03/14 07:08, Razvan Cojocaru wrote:
> On 07/03/2014 01:56 PM, George Dunlap wrote:
>> On Wed, Jul 2, 2014 at 5:30 PM, Razvan Cojocaru
>> <rcojocaru@bitdefender.com> wrote:
>>> Moved an enum definition before the typedef that uses it.
>> Presumably you want this because you have an out-of-tree program that
>> you want to compile against libxc.  You do realize that libxc isn't a
>> stable API, right?  That it may change in incompatible ways in every
>> release?
> Yes, I've glimpsed into that by following it since Xen 4.1.
> I am indeed compiling an application against libxc.

I also have one that is both libxc and libxl in c++.  I fixed it by 
moving the
typedef:



diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 13f816b..37031ad 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -119,7 +119,6 @@ typedef struct xc_interface_core xc_interface;
  typedef struct xc_interface_core xc_evtchn;
  typedef struct xc_interface_core xc_gnttab;
  typedef struct xc_interface_core xc_gntshr;
-typedef enum xc_error_code xc_error_code;


  /*
@@ -1756,14 +1755,14 @@ int xc_hvm_inject_trap(
   */


-enum xc_error_code {
+typedef enum xc_error_code {
    XC_ERROR_NONE = 0,
    XC_INTERNAL_ERROR = 1,
    XC_INVALID_KERNEL = 2,
    XC_INVALID_PARAM = 3,
    XC_OUT_OF_MEMORY = 4,
    /* new codes need to be added to xc_error_level_to_desc too */
-};
+} xc_error_code;

  #define XC_MAX_ERROR_MSG_LEN 1024
  typedef struct xc_error {


So I would like to see either of these done.

>> I presume you'd rather use a stable API -- in which case maybe we
>> should ask what it is your application needs, and we can try to come
>> up with a way to support you.  (Perhaps by declaring certain parts of
>> the libxc interface as "stable", if libxl isn't suitable for some
>> reason.)


I have no need for a stable API; but it might allow the C++ code to not
include this file from /usr/include/xenctrl.h


    -Don Slutz

Re: [PATCH] xenctrl: Make the headers C++ friendly

[Ian Campbell]

On Wed, 2014-07-02 at 19:30 +0300, Razvan Cojocaru wrote:
> Moved an enum definition before the typedef that uses it.
> 
> Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

Previously the idea of C++ifying the headers has been controversial but
this particular patch seems OK.

Acked + applied.

Ian.

Re: [PATCH] xenctrl: Make the headers C++ friendly

[Razvan Cojocaru]

On 07/16/2014 05:48 PM, Ian Campbell wrote:
> On Wed, 2014-07-02 at 19:30 +0300, Razvan Cojocaru wrote:
>> Moved an enum definition before the typedef that uses it.
>>
>> Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
>> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
> 
> Previously the idea of C++ifying the headers has been controversial but
> this particular patch seems OK.
> 
> Acked + applied.

Thanks!