macro.h: let F_TYPE_CMP() macro fail to compile, if second parameter is not const

[elogind.git] / src / shared / macro.h

diff --git a/src/shared/macro.h b/src/shared/macro.h
index cca41a3f6ad7311877211d788a6d0d076285c909..2bb72f0d167626413aa5d91c1182050cc41da57d 100644 (file)
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -66,12 +66,16 @@
 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
 #endif
 
+#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
+#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
 
 static inline size_t ALIGN_TO(size_t l, size_t ali) {
         return ((l + ali - 1) & ~(ali - 1));
 }
 
+#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p))
+
 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 
 /*
@@ -260,6 +264,24 @@ do {                                                                    \
         }                                                               \
 } while(false)
 
+/* Remove this macro, when the kernel has f_type as unsigned int or long
+ * for every architecure. Currently some 64bit architecures (like s390x)
+ * have int in the kernel, but long in userspace for f_type, so glibc
+ * extends the int to long and carries over the sign. Negative numbers are
+ * caused by the 32bit magic constants in linux/magic.h stuffed into the
+ * signed int in the kernel and these negative numbers are extended to
+ * long, which cannot be simply compared to the magic constants anymore.
+ */
+#define F_TYPE_CMP(f_type, magic)                                       \
+        __extension__ ({                                                \
+                        __SWORD_TYPE _f = (f_type);                     \
+                        const __SWORD_TYPE _c = (magic);                \
+                        const int _c32 = 1 ? (magic)                    \
+                                    : sizeof((int[magic]){0});          \
+                        (_f == _c || _f == _c32 );                      \
+                })
+
+
 /* Returns the number of chars needed to format variables of the
  * specified type as a decimal string. Adds in extra space for a
  * negative '-' prefix. */