source/texk/web2c/luatexdir/tex/memoryword.h

   1 /* memoryword.h
   2
   3    Copyright 2009-2010 Taco Hoekwater <taco@luatex.org>
   4
   5    This file is part of LuaTeX.
   6
   7    LuaTeX is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2 of the License, or (at your
  10    option) any later version.
  11
  12    LuaTeX is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */
  19
  20
  21 /* This header file is extra special because it is read in from
  22    within the pascal source */
  23
  24 #ifndef MEMORYWORD_H
  25 #  define MEMORYWORD_H
  26
  27 /* texmfmem.h: the memory_word type, which is too hard to translate
  28    automatically from Pascal.  We have to make sure the byte-swapping
  29    that the (un)dumping routines do suffices to put things in the right
  30    place in memory.
  31
  32    A memory_word can be broken up into a `twohalves' or a
  33    `fourquarters', and a `twohalves' can be further broken up.  Here is
  34    a picture.  ..._M = most significant byte, ..._L = least significant
  35    byte.
  36
  37
  38    BigEndian:
  39    twohalves.v:  RH_MM RH_ML RH_LM RH_LL LH_MM LH_ML LH_LM LH_LL
  40    twohalves.u:  ---------JUNK---------- ----B0----- ----B1-----
  41    fourquarters: ----B0----- ----B1----- ----B2----- ----B3-----
  42    twoints:      ---------CINT0--------- ---------CINT1---------
  43
  44    LittleEndian:
  45    twohalves.v:  LH_LL LH_LM LH_ML LH_MM RH_LL RH_LM RH_ML RH_MM
  46    twohalves.u:  ----B1----- ----B0-----
  47    fourquarters: ----B3----- ----B2----- ----B1----- ----B0-----
  48    twoints:      ---------CINT1--------- ---------CINT0---------
  49
  50 */
  51
  52
  53 typedef union {
  54     struct {
  55 #  ifdef WORDS_BIGENDIAN
  56         halfword RH, LH;
  57 #  else
  58         halfword LH, RH;
  59 #  endif
  60     } v;
  61
  62     struct {                    /* Make B0,B1 overlap the most significant bytes of LH.  */
  63 #  ifdef WORDS_BIGENDIAN
  64         halfword junk;
  65         quarterword B0, B1;
  66 #  else                         /* not WORDS_BIGENDIAN */
  67         /* If 32-bit memory words, have to do something.  */
  68         quarterword B1, B0;
  69 #  endif                        /* LittleEndian */
  70     } u;
  71 } two_halves;
  72
  73 typedef struct {
  74     struct {
  75 #  ifdef WORDS_BIGENDIAN
  76         quarterword B0, B1, B2, B3;
  77 #  else
  78         quarterword B3, B2, B1, B0;
  79 #  endif
  80     } u;
  81 } four_quarters;
  82
  83 typedef struct {
  84 #  ifdef WORDS_BIGENDIAN
  85     int CINT0, CINT1;
  86 #  else
  87     int CINT1, CINT0;
  88 #  endif
  89 } two_ints;
  90
  91 typedef struct {
  92     glue_ratio GLUE;
  93 } glues;
  94
  95 typedef union {
  96     two_halves hh;
  97     four_quarters qqqq;
  98     two_ints ii;
  99     glues gg;
 100 } memory_word;
 101
 102 #  define b0 u.B0
 103 #  define b1 u.B1
 104 #  define b2 u.B2
 105 #  define b3 u.B3
 106
 107 #  define rh v.RH
 108 #  define lhfield v.LH
 109
 110 #  define cint ii.CINT0
 111 #  define cint1 ii.CINT1
 112
 113 #  define gr gg.GLUE
 114
 115 /* the next five defines are needed for the prototypes in web2c's coerce.h */
 116
 117 #  define memoryword memory_word
 118 #  define strnumber str_number
 119 #  define packedASCIIcode packed_ASCII_code
 120 #  define poolpointer pool_pointer
 121
 122 typedef FILE *word_file;
 123
 124 #  ifdef DEBUG
 125 extern void print_word(memory_word w);
 126 #  endif
 127
 128 #endif