internal/struct.h

   1 #ifndef INTERNAL_STRUCT_H                                /*-*-C-*-vi:se ft=c:*/
   2 #define INTERNAL_STRUCT_H
   3 /**
   4  * @author     Ruby developers <ruby-core@ruby-lang.org>
   5  * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
   6  *             Permission  is hereby  granted,  to  either redistribute  and/or
   7  *             modify this file, provided that  the conditions mentioned in the
   8  *             file COPYING are met.  Consult the file for details.
   9  * @brief      Internal header for Struct.
  10  */
  11 #include "ruby/internal/stdbool.h"     /* for bool */
  12 #include "ruby/ruby.h"          /* for struct RBasic */
  13
  14 enum {
  15     RSTRUCT_EMBED_LEN_MASK = RUBY_FL_USER7 | RUBY_FL_USER6 | RUBY_FL_USER5 | RUBY_FL_USER4 |
  16                                  RUBY_FL_USER3 | RUBY_FL_USER2 | RUBY_FL_USER1,
  17     RSTRUCT_EMBED_LEN_SHIFT = (RUBY_FL_USHIFT+1),
  18     RSTRUCT_TRANSIENT_FLAG = RUBY_FL_USER8,
  19 };
  20
  21 struct RStruct {
  22     struct RBasic basic;
  23     union {
  24         struct {
  25             long len;
  26             const VALUE *ptr;
  27         } heap;
  28         /* This is a length 1 array because:
  29          *   1. GCC has a bug that does not optimize C flexible array members
  30          *      (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102452)
  31          *   2. Zero length arrays are not supported by all compilers
  32          */
  33         const VALUE ary[1];
  34     } as;
  35 };
  36
  37 #define RSTRUCT(obj) ((struct RStruct *)(obj))
  38