RARRAY_AREF: convert into an inline function

RARRAY_AREF has been a macro for reasons.  We might not be able to
change that for public APIs, but why not relax the situation internally
to make it an inline function.

array.c

@@ -7221,7 +7221,7 @@ rb_ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VA
 	return rb_ary_new_capa(0);
       case 1:
 	i = rnds[0];
-	return rb_ary_new_from_values(1, &RARRAY_AREF(ary, i));
+	return rb_ary_new_from_args(1, RARRAY_AREF(ary, i));
       case 2:
 	i = rnds[0];
 	j = rnds[1];

complex.c

@@ -19,6 +19,7 @@
 #define NDEBUG
 #include "id.h"
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/class.h"
 #include "internal/complex.h"
 #include "internal/math.h"

dir.c

@@ -105,6 +105,7 @@ char *strchr(char*,char);
 #include "encindex.h"
 #include "id.h"
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/dir.h"
 #include "internal/encoding.h"
 #include "internal/error.h"

enumerator.c

@@ -2087,7 +2087,8 @@ lazy_flat_map_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo
         long i;
         LAZY_MEMO_RESET_BREAK(result);
         for (i = 0; i + 1 < RARRAY_LEN(ary); i++) {
-            lazy_yielder_yield(result, proc_index, 1, &RARRAY_AREF(ary, i));
+            const VALUE argv = RARRAY_AREF(ary, i);
+            lazy_yielder_yield(result, proc_index, 1, &argv);
         }
         if (break_p) LAZY_MEMO_SET_BREAK(result);
         if (i >= RARRAY_LEN(ary)) return 0;

include/ruby/internal/core/rarray.h

@@ -256,20 +256,15 @@ RARRAY_ASET(VALUE ary, long i, VALUE v)
         RB_OBJ_WRITE(ary, &ptr[i], v));
 }
 
-/* RARRAY_AREF is used as a lvalue.  Cannot be a function. */
-#if 0
-RBIMPL_ATTR_PURE_UNLESS_DEBUG()
-RBIMPL_ATTR_ARTIFICIAL()
-static inline VALUE
-RARRAY_AREF(VALUE ary, long i)
-{
-    RBIMPL_ASSERT_TYPE(ary, RUBY_T_ARRAY);
-
-    return RARRAY_CONST_PTR_TRANSIENT(ary)[i];
-}
-#else
-# undef RARRAY_AREF
-# define RARRAY_AREF(a, i) RARRAY_CONST_PTR_TRANSIENT(a)[i]
-#endif
+/*
+ * :FIXME: we want to convert RARRAY_AREF into an inline function (to add rooms
+ * for more sanity checks).  However there were situations where the address of
+ * this macro is taken i.e. &RARRAY_AREF(...).  They cannot be possible if this
+ * is not a  macro.  Such usages are abuse, and  we eliminated them internally.
+ * However we are afraid  of similar things to remain in  the wild.  This macro
+ * remains as  it is due to  that.  If we could  warn such usages we  can set a
+ * transition path, but currently no way is found to do so.
+ */
+#define RARRAY_AREF(a, i) RARRAY_CONST_PTR_TRANSIENT(a)[i]
 
 #endif /* RBIMPL_RARRAY_H */

internal.h

@@ -31,6 +31,9 @@
 /* Following macros were formerly defined in this header but moved to somewhere
  * else.  In order to detect them we undef here. */
 
+/* internal/array.h */
+#undef RARRAY_AREF
+
 /* internal/class.h */
 #undef RClass
 #undef RCLASS_SUPER

internal/array.h

@@ -100,4 +100,15 @@ RARY_TRANSIENT_UNSET(VALUE ary)
     })
 #endif
 
+#undef RARRAY_AREF
+RBIMPL_ATTR_PURE_UNLESS_DEBUG()
+RBIMPL_ATTR_ARTIFICIAL()
+static inline VALUE
+RARRAY_AREF(VALUE ary, long i)
+{
+    RBIMPL_ASSERT_TYPE(ary, RUBY_T_ARRAY);
+
+    return RARRAY_CONST_PTR_TRANSIENT(ary)[i];
+}
+
 #endif /* INTERNAL_ARRAY_H */

marshal.c

@@ -22,6 +22,7 @@
 #include "encindex.h"
 #include "id_table.h"
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/bignum.h"
 #include "internal/class.h"
 #include "internal/encoding.h"

pack.c

@@ -17,6 +17,7 @@
 #include <sys/types.h>
 
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/bits.h"
 #include "internal/string.h"
 #include "internal/symbol.h"

random.c

@@ -56,6 +56,7 @@
 #endif
 
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/compilers.h"
 #include "internal/numeric.h"
 #include "internal/random.h"

rational.c

@@ -24,6 +24,7 @@
 #define NDEBUG
 #include "id.h"
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/complex.h"
 #include "internal/gc.h"
 #include "internal/numeric.h"

transcode.c

@@ -14,6 +14,7 @@
 #include <ctype.h>
 
 #include "internal.h"
+#include "internal/array.h"
 #include "internal/inits.h"
 #include "internal/object.h"
 #include "internal/string.h"