[XEN RFC] xen: avoid grep fodder define and undef

[Federico Serafini <federico.serafini@bugseng.com>]

Place an "#if 0" before grep fodder definitions and remove the
"#undef".

This addresses several violations of MISRA C:2012 Rule 5.5
("Identifiers shall be distinct from macro names").

No functional change.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
---
Hello, I would like to know what you think about this change.
If you want to keep grep fodders as they are, an alternative could be to
deviate violations of Rule 5.5 involving the TYPE_SAFE macro.
---
 xen/include/xen/iommu.h    |  5 +----
 xen/include/xen/mm-frame.h | 15 +++------------
 2 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 9621459c63..ef57f31417 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -33,13 +33,10 @@ TYPE_SAFE(uint64_t, dfn);
 #define PRI_dfn     PRIx64
 #define INVALID_DFN _dfn(~0ULL)
 
-#ifndef dfn_t
+#if 0
 #define dfn_t /* Grep fodder: dfn_t, _dfn() and dfn_x() are defined above */
 #define _dfn
 #define dfn_x
-#undef dfn_t
-#undef _dfn
-#undef dfn_x
 #endif
 
 static inline dfn_t __must_check dfn_add(dfn_t dfn, unsigned long i)
diff --git a/xen/include/xen/mm-frame.h b/xen/include/xen/mm-frame.h
index c25e836f25..d973aec901 100644
--- a/xen/include/xen/mm-frame.h
+++ b/xen/include/xen/mm-frame.h
@@ -14,13 +14,10 @@ TYPE_SAFE(unsigned long, mfn);
  */
 #define INVALID_MFN_INITIALIZER { INVALID_MFN_RAW }
 
-#ifndef mfn_t
+#if 0
 #define mfn_t /* Grep fodder: mfn_t, _mfn() and mfn_x() are defined above */
 #define _mfn
 #define mfn_x
-#undef mfn_t
-#undef _mfn
-#undef mfn_x
 #endif
 
 static inline mfn_t __must_check mfn_add(mfn_t mfn, unsigned long i)
@@ -53,13 +50,10 @@ TYPE_SAFE(unsigned long, gfn);
  */
 #define INVALID_GFN_INITIALIZER { INVALID_GFN_RAW }
 
-#ifndef gfn_t
+#if 0
 #define gfn_t /* Grep fodder: gfn_t, _gfn() and gfn_x() are defined above */
 #define _gfn
 #define gfn_x
-#undef gfn_t
-#undef _gfn
-#undef gfn_x
 #endif
 
 static inline gfn_t __must_check gfn_add(gfn_t gfn, unsigned long i)
@@ -85,13 +79,10 @@ static inline bool gfn_eq(gfn_t x, gfn_t y)
 TYPE_SAFE(unsigned long, pfn);
 #define PRI_pfn          "05lx"
 
-#ifndef pfn_t
+#if 0
 #define pfn_t /* Grep fodder: pfn_t, _pfn() and pfn_x() are defined above */
 #define _pfn
 #define pfn_x
-#undef pfn_t
-#undef _pfn
-#undef pfn_x
 #endif
 
 #endif /* __XEN_FRAME_NUM_H__ */
-- 
2.34.1