[xen staging] libxc: simplify HYPERCALL_BUFFER()

[patchbot@xxxxxxx]

commit 5c34b9af05b9e5abd25d88efc4fb783136547810
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Aug 13 16:50:09 2021 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Aug 13 16:50:09 2021 +0200

    libxc: simplify HYPERCALL_BUFFER()
    
    _hcbuf_buf1 has been there only for a pointer comparison to validate
    type compatibility. The same can be achieved by not using typeof() on
    the definition of what so far was _hcbuf_buf2, as the initializer has
    to also be type-compatible. Drop _hcbuf_buf1 and the comaprison;
    rename _hcbuf_buf2.
    
    Since we're already using compiler extensions here, don't be shy and
    also omit the middle operand of the involved ?: operator.
    
    Bring line continuation character placement in line with that of
    related macros.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 tools/include/xenctrl.h | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 14adaa0c10..b77726eab7 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -247,13 +247,10 @@ typedef struct xc_hypercall_buffer xc_hypercall_buffer_t;
 /*
  * Returns the hypercall_buffer associated with a variable.
  */
-#define HYPERCALL_BUFFER(_name)                                 \
-    ({  xc_hypercall_buffer_t _hcbuf_buf1;                      \
-        typeof(XC__HYPERCALL_BUFFER_NAME(_name)) *_hcbuf_buf2 = \
-                &XC__HYPERCALL_BUFFER_NAME(_name);              \
-        (void)(&_hcbuf_buf1 == _hcbuf_buf2);                    \
-        (_hcbuf_buf2)->param_shadow ?                           \
-                (_hcbuf_buf2)->param_shadow : (_hcbuf_buf2);    \
+#define HYPERCALL_BUFFER(_name)                                \
+    ({  xc_hypercall_buffer_t *_hcbuf_buf =                    \
+                &XC__HYPERCALL_BUFFER_NAME(_name);             \
+        _hcbuf_buf->param_shadow ?: _hcbuf_buf;                \
      })
 
 #define HYPERCALL_BUFFER_INIT_NO_BOUNCE .dir = 0, .sz = 0, .ubuf = (void *)-1
--
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