Add IMPLY() and EQUIV() macros

Added for upstream compatibility, they are of the form:

* IMPLY(a, b) - if (a) then (b)
* EQUIV(a, b) - if (a) then (b) *AND* if (b) then (a)

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

diff --git a/lib/libspl/include/assert.h b/lib/libspl/include/assert.h
index d749d1e9c3bf8a440fc181567bf089b68e3efd86..52924e8baf96bc3658ddb4d3466fcd520b21a65d 100644 (file)
--- a/lib/libspl/include/assert.h
+++ b/lib/libspl/include/assert.h
@@ -63,6 +63,13 @@ __assert_c99(const char *expr, const char *file, int line, const char *func)
 
 extern void __assert(const char *, const char *, int);
 
+static inline int
+assfail(const char *buf, const char *file, int line)
+{
+       __assert(buf, file, line);
+       return (0);
+}
+
 /* BEGIN CSTYLED */
 #define        VERIFY3_IMPL(LEFT, OP, RIGHT, TYPE) do { \
        const TYPE __left = (TYPE)(LEFT); \
@@ -72,7 +79,7 @@ extern void __assert(const char *, const char *, int);
                (void) snprintf(__buf, 256, "%s %s %s (0x%llx %s 0x%llx)", \
                        #LEFT, #OP, #RIGHT, \
                        (u_longlong_t)__left, #OP, (u_longlong_t)__right); \
-               __assert(__buf, __FILE__, __LINE__); \
+               assfail(__buf, __FILE__, __LINE__); \
        } \
 } while (0)
 /* END CSTYLED */
@@ -88,12 +95,21 @@ extern void __assert(const char *, const char *, int);
 #define        ASSERT3P(x, y, z)       ((void)0)
 #define        ASSERT0(x)              ((void)0)
 #define        ASSERTV(x)
+#define        IMPLY(A, B)             ((void)0)
+#define        EQUIV(A, B)             ((void)0)
 #else
 #define        ASSERT3S(x, y, z)       VERIFY3S(x, y, z)
 #define        ASSERT3U(x, y, z)       VERIFY3U(x, y, z)
 #define        ASSERT3P(x, y, z)       VERIFY3P(x, y, z)
 #define        ASSERT0(x)              VERIFY0(x)
 #define        ASSERTV(x)              x
+#define        IMPLY(A, B) \
+       ((void)(((!(A)) || (B)) || \
+           assfail("(" #A ") implies (" #B ")", __FILE__, __LINE__)))
+#define        EQUIV(A, B) \
+       ((void)((!!(A) == !!(B)) || \
+           assfail("(" #A ") is equivalent to (" #B ")", __FILE__, __LINE__)))
+
 #endif  /* NDEBUG */
 
 #endif  /* _LIBSPL_ASSERT_H */