typesafe_cb: fix promotable types being incorrectly accepted by cast_if_type.

[ccan] / ccan / typesafe_cb / typesafe_cb.h

diff --git a/ccan/typesafe_cb/typesafe_cb.h b/ccan/typesafe_cb/typesafe_cb.h
index f5e416de2de26c0e65605c5ed923ce0177cf4c33..39b0312453f4a93b41c5f079468c83eecb7817ca 100644 (file)
--- a/ccan/typesafe_cb/typesafe_cb.h
+++ b/ccan/typesafe_cb/typesafe_cb.h
@@ -12,9 +12,8 @@
  *
  * This macro is used to create functions which allow multiple types.
  * The result of this macro is used somewhere that a @desttype type is
- * expected: if @expr was of type @oktype, it will be cast to
- * @desttype type.  As a result, if @expr is any type other than
- * @oktype or @desttype, a compiler warning will be issued.
+ * expected: if @test is exactly of type @oktype, then @expr will be
+ * cast to @desttype type, otherwise left alone.
  *
  * This macro can be used in static initializers.
  *
@@ -31,7 +30,7 @@
  *             _set_some_value(cast_if_type(void *, (e), (e), unsigned long))
  */
 #define cast_if_type(desttype, expr, test, oktype)                     \
-__builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(test):0), oktype), \
+       __builtin_choose_expr(__builtin_types_compatible_p(typeof(test), oktype), \
                        (desttype)(expr), (expr))
 #else
 #define cast_if_type(desttype, expr, test, oktype) ((desttype)(expr))
@@ -61,7 +60,9 @@ __builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(test):0), oktype),
        cast_if_type(desttype,                                          \
                     cast_if_type(desttype,                             \
                                  cast_if_type(desttype, (expr), (test), ok1), \
+                                 (test),                               \
                                  ok2),                                 \
+                    (test),                                            \
                     ok3)
 
 /**
@@ -103,10 +104,8 @@ __builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(test):0), oktype),
  *     #define register_callback(fn, arg) \
  *             _register_callback(typesafe_cb_const(void, (fn), (arg)), (arg))
  */
-#define typesafe_cb_const(rtype, fn, arg)                              \
-       sizeof((fn)((const void *)0)),                                  \
-               cast_if_type(rtype (*)(const void *),                   \
-                            (fn), (fn)(arg), rtype (*)(typeof(arg)))
+#define typesafe_cb_const(rtype, fn, arg)                      \
+       cast_if_type(rtype (*)(const void *), (fn), (fn)(arg), rtype)
 
 /**
  * typesafe_cb_preargs - cast a callback function if it matches the arg
@@ -124,8 +123,9 @@ __builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(test):0), oktype),
  *                                (arg))
  */
 #define typesafe_cb_preargs(rtype, fn, arg, ...)                       \
-       cast_if_type(rtype (*)(__VA_ARGS__, void *), (fn), (fn),        \
+       cast_if_type(rtype (*)(__VA_ARGS__, void *), (fn), &*(fn),      \
                     rtype (*)(__VA_ARGS__, typeof(arg)))
+
 /**
  * typesafe_cb_postargs - cast a callback function if it matches the arg
  * @rtype: the return type of the callback function
@@ -142,8 +142,9 @@ __builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(test):0), oktype),
  *                                (arg))
  */
 #define typesafe_cb_postargs(rtype, fn, arg, ...)                      \
-       cast_if_type(rtype (*)(void *, __VA_ARGS__), (fn), (fn),        \
+       cast_if_type(rtype (*)(void *, __VA_ARGS__), (fn), &*(fn),      \
                     rtype (*)(typeof(arg), __VA_ARGS__))
+
 /**
  * typesafe_cb_cmp - cast a compare function if it matches the arg
  * @rtype: the return type of the callback function
@@ -166,7 +167,7 @@ __builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(test):0), oktype),
  *                       typesafe_cb_cmp(int, (cmpfn), (base)), (arg))
  */
 #define typesafe_cb_cmp(rtype, cmpfn, arg)                             \
-       cast_if_type(rtype (*)(const void *, const void *), (cmpfn),    \
+       cast_if_type(rtype (*)(const void *, const void *), (cmpfn), &*(cmpfn), \
                     rtype (*)(const typeof(*arg)*, const typeof(*arg)*))
                     
 #endif /* CCAN_CAST_IF_TYPE_H */