From 46bfa65fccf58cee280bf552193f93388b00d16d Mon Sep 17 00:00:00 2001
From: normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 27 Jan 2018 21:04:42 +0000
Subject: [PATCH] internal.h: add BITFIELD macro to aid C99 users

I plan to use this macro to pack other enums in the VM.

* internal.h: add BITFIELD macro
* method.h: use BITFIELD for rb_method_visibility_t
  [ruby-core:85074] [Misc #14395]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62077 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 internal.h | 13 +++++++++++++
 method.h   |  8 +-------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/internal.h b/internal.h
index 59f5d640cc..f6742cd458 100644
--- a/internal.h
+++ b/internal.h
@@ -2066,6 +2066,19 @@ rb_obj_builtin_type(VALUE obj)
 # define FLEX_ARY_LEN 1 /* VALUE ary[1]; */
 #endif
 
+/*
+ * For declaring bitfields out of non-unsigned int types:
+ *   struct date {
+ *      BITFIELD(enum months) month:4;
+ *      ...
+ *   };
+ */
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+# define BITFIELD(type) type
+#else
+# define BITFIELD(type) unsigned int
+#endif
+
 #if defined(__cplusplus)
 #if 0
 { /* satisfy cc-mode */
diff --git a/method.h b/method.h
index 83f3acac06..e2d121d9b8 100644
--- a/method.h
+++ b/method.h
@@ -32,16 +32,10 @@ typedef enum {
     METHOD_VISI_MASK = 0x03
 } rb_method_visibility_t;
 
-#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
-#define bits_t rb_method_visibility_t
-#else
-#define bits_t unsigned int
-#endif
 typedef struct rb_scope_visi_struct {
-    bits_t method_visi : 3;
+    BITFIELD(rb_method_visibility_t) method_visi : 3;
     unsigned int module_func : 1;
 } rb_scope_visibility_t;
-#undef bits_t
 
 /*! CREF (Class REFerence) */
 typedef struct rb_cref_struct {