[Feature #19579] Remove !USE_RVARGC code (#7655)

Remove !USE_RVARGC code

[Feature #19579]

The Variable Width Allocation feature was turned on by default in Ruby
3.2. Since then, we haven't received bug reports or backports to the
non-Variable Width Allocation code paths, so we assume that nobody is
using it. We also don't plan on maintaining the non-Variable Width
Allocation code, so we are going to remove it.

4 files changed, 0 insertions, 90 deletions

diff --git a/include/ruby/internal/config.h b/include/ruby/internal/config.h
index aa63376d7c..da070f0979 100644
--- a/include/ruby/internal/config.h
+++ b/include/ruby/internal/config.h
@@ -148,8 +148,4 @@
 # undef RBIMPL_TEST3
 #endif /* HAVE_VA_ARGS_MACRO */
 
-#ifndef USE_RVARGC
-# define USE_RVARGC 1
-#endif
-
 #endif /* RBIMPL_CONFIG_H */
diff --git a/include/ruby/internal/core/rarray.h b/include/ruby/internal/core/rarray.h
index 8fc3062f1b..9670f93d0c 100644
--- a/include/ruby/internal/core/rarray.h
+++ b/include/ruby/internal/core/rarray.h
@@ -130,12 +130,8 @@ enum ruby_rarray_flags {
      * 3rd parties must  not be aware that  there even is more than  one way to
      * store array elements.  It was a bad idea to expose this to them.
      */
-#if USE_RVARGC
     RARRAY_EMBED_LEN_MASK  = RUBY_FL_USER9 | RUBY_FL_USER8 | RUBY_FL_USER7 | RUBY_FL_USER6 |
                                  RUBY_FL_USER5 | RUBY_FL_USER4 | RUBY_FL_USER3
-#else
-    RARRAY_EMBED_LEN_MASK  = RUBY_FL_USER4 | RUBY_FL_USER3
-#endif
 
 #if USE_TRANSIENT_HEAP
     ,
@@ -163,13 +159,6 @@ enum ruby_rarray_flags {
 enum ruby_rarray_consts {
     /** Where ::RARRAY_EMBED_LEN_MASK resides. */
     RARRAY_EMBED_LEN_SHIFT = RUBY_FL_USHIFT + 3
-
-#if !USE_RVARGC
-    ,
-
-    /** Max possible number elements that can be embedded. */
-    RARRAY_EMBED_LEN_MAX   = RBIMPL_EMBED_LEN_MAX_OF(VALUE)
-#endif
 };
 
 /** Ruby's array. */
@@ -228,16 +217,12 @@ struct RArray {
          * to store its elements.  In this  case the length is encoded into the
          * flags.
          */
-#if USE_RVARGC
         /* This is a length 1 array because:
          *   1. GCC has a bug that does not optimize C flexible array members
          *      (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102452)
          *   2. Zero length arrays are not supported by all compilers
          */
         const VALUE ary[1];
-#else
-        const VALUE ary[RARRAY_EMBED_LEN_MAX];
-#endif
     } as;
 };
 
diff --git a/include/ruby/internal/core/robject.h b/include/ruby/internal/core/robject.h
index b1c2e1b0a9..dc1faad89f 100644
--- a/include/ruby/internal/core/robject.h
+++ b/include/ruby/internal/core/robject.h
@@ -74,17 +74,6 @@ enum ruby_robject_flags {
     ROBJECT_EMBED = RUBY_FL_USER1
 };
 
-#if !USE_RVARGC
-/**
- * This is an enum because GDB wants it (rather than a macro).  People need not
- * bother.
- */
-enum ruby_robject_consts {
-    /** Max possible number of instance variables that can be embedded. */
-    ROBJECT_EMBED_LEN_MAX = RBIMPL_EMBED_LEN_MAX_OF(VALUE)
-};
-#endif
-
 struct st_table;
 
 /**
@@ -118,7 +107,6 @@ struct RObject {
             struct rb_id_table *iv_index_tbl;
         } heap;
 
-#if USE_RVARGC
         /* Embedded instance variables. When an object is small enough, it
          * uses this area to store the instance variables.
          *
@@ -128,13 +116,6 @@ struct RObject {
          *   2. Zero length arrays are not supported by all compilers
          */
         VALUE ary[1];
-#else
-        /**
-        * Embedded instance  variables.  When  an object  is small  enough, it
-        * uses this area to store the instance variables.
-        */
-        VALUE ary[ROBJECT_EMBED_LEN_MAX];
-#endif
     } as;
 };
 
diff --git a/include/ruby/internal/core/rstring.h b/include/ruby/internal/core/rstring.h
index e394ab7dca..777fe6dab1 100644
--- a/include/ruby/internal/core/rstring.h
+++ b/include/ruby/internal/core/rstring.h
@@ -42,11 +42,6 @@
 
 /** @cond INTERNAL_MACRO */
 #define RSTRING_NOEMBED         RSTRING_NOEMBED
-#if !USE_RVARGC
-#define RSTRING_EMBED_LEN_MASK  RSTRING_EMBED_LEN_MASK
-#define RSTRING_EMBED_LEN_SHIFT RSTRING_EMBED_LEN_SHIFT
-#define RSTRING_EMBED_LEN_MAX   RSTRING_EMBED_LEN_MAX
-#endif
 #define RSTRING_FSTR            RSTRING_FSTR
 #define RSTRING_EMBED_LEN RSTRING_EMBED_LEN
 #define RSTRING_LEN       RSTRING_LEN
@@ -162,21 +157,6 @@ enum ruby_rstring_flags {
      */
     RSTRING_NOEMBED         = RUBY_FL_USER1,
 
-#if !USE_RVARGC
-    /**
-     * When a  string employs embedded strategy  (see ::RSTRING_NOEMBED), these
-     * bits  are  used to  store  the  number  of  bytes actually  filled  into
-     * ::RString::ary.
-     *
-     * @internal
-     *
-     * 3rd parties must  not be aware that  there even is more than  one way to
-     * store a string.  Might better be hidden.
-     */
-    RSTRING_EMBED_LEN_MASK  = RUBY_FL_USER2 | RUBY_FL_USER3 | RUBY_FL_USER4 |
-                              RUBY_FL_USER5 | RUBY_FL_USER6,
-#endif
-
     /* Actually,  string  encodings are  also  encoded  into the  flags,  using
      * remaining bits.*/
 
@@ -202,20 +182,6 @@ enum ruby_rstring_flags {
     RSTRING_FSTR            = RUBY_FL_USER17
 };
 
-#if !USE_RVARGC
-/**
- * This is an enum because GDB wants it (rather than a macro).  People need not
- * bother.
- */
-enum ruby_rstring_consts {
-    /** Where ::RSTRING_EMBED_LEN_MASK resides. */
-    RSTRING_EMBED_LEN_SHIFT = RUBY_FL_USHIFT + 2,
-
-    /** Max possible number of characters that can be embedded. */
-    RSTRING_EMBED_LEN_MAX   = RBIMPL_EMBED_LEN_MAX_OF(char) - 1
-};
-#endif
-
 /**
  * Ruby's String.  A string in ruby conceptually has these information:
  *
@@ -279,7 +245,6 @@ struct RString {
 
         /** Embedded contents. */
         struct {
-#if USE_RVARGC
             long len;
             /* This is a length 1 array because:
              *   1. GCC has a bug that does not optimize C flexible array members
@@ -287,16 +252,6 @@ struct RString {
              *   2. Zero length arrays are not supported by all compilers
              */
             char ary[1];
-#else
-            /**
-             * When a  string is short enough,  it uses this area  to store the
-             * contents themselves.  This was  impractical in the 20th century,
-             * but these days 64 bit machines can typically hold 24 bytes here.
-             * Could be sufficiently large.  In this case the length is encoded
-             * into the flags.
-             */
-            char ary[RSTRING_EMBED_LEN_MAX + 1];
-#endif
         } embed;
     } as;
 };
@@ -425,15 +380,8 @@ RSTRING_EMBED_LEN(VALUE str)
     RBIMPL_ASSERT_TYPE(str, RUBY_T_STRING);
     RBIMPL_ASSERT_OR_ASSUME(! RB_FL_ANY_RAW(str, RSTRING_NOEMBED));
 
-#if USE_RVARGC
     long f = RSTRING(str)->as.embed.len;
     return f;
-#else
-    VALUE f = RBASIC(str)->flags;
-    f &= RSTRING_EMBED_LEN_MASK;
-    f >>= RSTRING_EMBED_LEN_SHIFT;
-    return RBIMPL_CAST((long)f);
-#endif
 }
 
 RBIMPL_WARNING_PUSH()