Allow using clang 15 with -Werror and -Wunreachable-code-generic-assoc (#4884)

Pre C17, there was ambiguity about the type of the controlling expression
in __Generic(). C17 explicitly states that it is subject to rvalue
promotions, which removes qualification from the outermost (or is that
deepest?) type modifier (or the base type if there are no modifiers).

(To clarify with an example, a FOO const * const will become FOO const *
as far as __Generic() is concerned.)

clang 15, perhaps anticipating C17, has -Wunreachabale-code-generic-assoc,
which warns if a __Generic() alternative type is unreachable, e.g.
FOO const * const. This change gets rid of such alternatives in a couple
of macros.

This builds and passes such tests as I can do compiling with gcc, clang 14,
and clang 15.

diff --git a/src/lib/server/cf_util.h b/src/lib/server/cf_util.h
index 6bfb77a68647c57fc6dadc85b8b9183b57c05151..d668fd3a411760c4633f0aa285bcbfeaab8b9d82 100644 (file)
--- a/src/lib/server/cf_util.h
+++ b/src/lib/server/cf_util.h
@@ -66,13 +66,10 @@ typedef struct cf_data CONF_DATA;   //!< #CONF_ITEM used to associate arbitrary da
 _Generic((_cf), \
        CONF_SECTION *                  : cf_section_to_item((CONF_SECTION const *)_cf), \
        CONF_SECTION const *            : cf_section_to_item((CONF_SECTION const *)_cf), \
-       CONF_SECTION const * const      : cf_section_to_item((CONF_SECTION const * const)_cf), \
        CONF_PAIR *                     : cf_pair_to_item((CONF_PAIR const *)_cf), \
        CONF_PAIR const *               : cf_pair_to_item((CONF_PAIR const *)_cf), \
-       CONF_PAIR const * const         : cf_pair_to_item((CONF_PAIR const * const)_cf), \
        CONF_DATA *                     : cf_data_to_item((CONF_DATA const *)_cf), \
        CONF_DATA const *               : cf_data_to_item((CONF_DATA const *)_cf), \
-       CONF_DATA const * const         : cf_data_to_item((CONF_DATA const * const)_cf), \
        default: _cf \
 )
 

diff --git a/src/lib/util/value.h b/src/lib/util/value.h
index 0bfe57ec728785e2a12bc93647e7f55ce223960b..5f2884c29a8fd74673b0e62ddf06b2672a604a83 100644 (file)
--- a/src/lib/util/value.h
+++ b/src/lib/util/value.h
@@ -687,25 +687,15 @@ _Generic((_var), \
        fr_ethernet_t const *   : fr_value_box_ethernet_addr, \
        bool                    : fr_value_box_bool, \
        uint8_t                 : fr_value_box_uint8, \
-       uint8_t const           : fr_value_box_uint8, \
        uint16_t                : fr_value_box_uint16, \
-       uint16_t const          : fr_value_box_uint16, \
        uint32_t                : fr_value_box_uint32, \
-       uint32_t const          : fr_value_box_uint32, \
        uint64_t                : fr_value_box_uint64, \
-       uint64_t const          : fr_value_box_uint64, \
        int8_t                  : fr_value_box_int8, \
-       int8_t const            : fr_value_box_int8, \
        int16_t                 : fr_value_box_int16, \
-       int16_t const           : fr_value_box_int16, \
        int32_t                 : fr_value_box_int32, \
-       int32_t const           : fr_value_box_int32, \
        int64_t                 : fr_value_box_int64, \
-       int64_t const           : fr_value_box_int64, \
        float                   : fr_value_box_float32, \
-       float const             : fr_value_box_float32, \
-       double                  : fr_value_box_float64, \
-       double const            : fr_value_box_float64 \
+       double                  : fr_value_box_float64 \
 )(_box, NULL, _var, _tainted)
 
 /** Automagically fill in a box, for types with length