298 lines
10 KiB
C
298 lines
10 KiB
C
/***********************************************************************/
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/* */
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/* Objective Caml */
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/* */
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/* Xavier Leroy and Damien Doligez, INRIA Rocquencourt */
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/* */
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/* Copyright 1996 Institut National de Recherche en Informatique et */
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/* en Automatique. All rights reserved. This file is distributed */
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/* under the terms of the GNU Library General Public License, with */
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/* the special exception on linking described in file ../LICENSE. */
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/* */
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/***********************************************************************/
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/* $Id$ */
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#ifndef _mlvalues_
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#define _mlvalues_
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#include "config.h"
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#include "misc.h"
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/* Definitions
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word: Four bytes on 32 and 16 bit architectures,
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eight bytes on 64 bit architectures.
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long: A C long integer.
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val: The ML representation of something. A long or a block or a pointer
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outside the heap. If it is a block, it is the (encoded) address
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of an object. If it is a long, it is encoded as well.
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block: Something allocated. It always has a header and some
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fields or some number of bytes (a multiple of the word size).
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field: A word-sized val which is part of a block.
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bp: Pointer to the first byte of a block. (a char *)
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op: Pointer to the first field of a block. (a value *)
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hp: Pointer to the header of a block. (a char *)
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int32: Four bytes on all architectures.
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int64: Eight bytes on all architectures.
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Remark: A block size is always a multiple of the word size, and at least
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one word plus the header.
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bosize: Size (in bytes) of the "bytes" part.
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wosize: Size (in words) of the "fields" part.
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bhsize: Size (in bytes) of the block with its header.
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whsize: Size (in words) of the block with its header.
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hd: A header.
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tag: The value of the tag field of the header.
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color: The value of the color field of the header.
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This is for use only by the GC.
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*/
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typedef long value;
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typedef unsigned long header_t;
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typedef unsigned long mlsize_t;
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typedef unsigned int tag_t; /* Actually, an unsigned char */
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typedef unsigned long color_t;
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typedef unsigned long mark_t;
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/* Longs vs blocks. */
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#define Is_long(x) (((x) & 1) != 0)
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#define Is_block(x) (((x) & 1) == 0)
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/* Conversion macro names are always of the form "to_from". */
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/* Example: Val_long as in "Val from long" or "Val of long". */
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#define Val_long(x) (((long)(x) << 1) + 1)
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#define Long_val(x) ((x) >> 1)
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#define Max_long ((1L << (8 * sizeof(value) - 2)) - 1)
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#define Min_long (-(1L << (8 * sizeof(value) - 2)))
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#define Val_int(x) Val_long(x)
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#define Int_val(x) ((int) Long_val(x))
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/* Structure of the header:
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For 16-bit and 32-bit architectures:
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+--------+-------+-----+
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| wosize | color | tag |
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+--------+-------+-----+
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bits 31 10 9 8 7 0
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For 64-bit architectures:
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+--------+-------+-----+
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| wosize | color | tag |
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+--------+-------+-----+
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bits 63 10 9 8 7 0
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*/
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#define Tag_hd(hd) ((tag_t) ((hd) & 0xFF))
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#define Wosize_hd(hd) ((mlsize_t) ((hd) >> 10))
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#define Hd_val(val) (((header_t *) (val)) [-1]) /* Also an l-value. */
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#define Hd_op(op) (Hd_val (op)) /* Also an l-value. */
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#define Hd_bp(bp) (Hd_val (bp)) /* Also an l-value. */
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#define Hd_hp(hp) (* ((header_t *) (hp))) /* Also an l-value. */
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#define Hp_val(val) ((char *) (((header_t *) (val)) - 1))
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#define Hp_op(op) (Hp_val (op))
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#define Hp_bp(bp) (Hp_val (bp))
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#define Val_op(op) ((value) (op))
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#define Val_hp(hp) ((value) (((header_t *) (hp)) + 1))
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#define Op_hp(hp) ((value *) Val_hp (hp))
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#define Bp_hp(hp) ((char *) Val_hp (hp))
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#define Num_tags (1 << 8)
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#ifdef ARCH_SIXTYFOUR
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#define Max_wosize ((1L << 54) - 1)
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#else
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#define Max_wosize ((1 << 22) - 1)
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#endif
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#define Wosize_val(val) (Wosize_hd (Hd_val (val)))
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#define Wosize_op(op) (Wosize_val (op))
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#define Wosize_bp(bp) (Wosize_val (bp))
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#define Wosize_hp(hp) (Wosize_hd (Hd_hp (hp)))
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#define Whsize_wosize(sz) ((sz) + 1)
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#define Wosize_whsize(sz) ((sz) - 1)
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#define Wosize_bhsize(sz) ((sz) / sizeof (value) - 1)
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#define Bsize_wsize(sz) ((sz) * sizeof (value))
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#define Wsize_bsize(sz) ((sz) / sizeof (value))
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#define Bhsize_wosize(sz) (Bsize_wsize (Whsize_wosize (sz)))
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#define Bhsize_bosize(sz) ((sz) + sizeof (header_t))
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#define Bosize_val(val) (Bsize_wsize (Wosize_val (val)))
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#define Bosize_op(op) (Bosize_val (Val_op (op)))
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#define Bosize_bp(bp) (Bosize_val (Val_bp (bp)))
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#define Bosize_hd(hd) (Bsize_wsize (Wosize_hd (hd)))
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#define Whsize_hp(hp) (Whsize_wosize (Wosize_hp (hp)))
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#define Whsize_val(val) (Whsize_hp (Hp_val (val)))
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#define Whsize_bp(bp) (Whsize_val (Val_bp (bp)))
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#define Whsize_hd(hd) (Whsize_wosize (Wosize_hd (hd)))
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#define Bhsize_hp(hp) (Bsize_wsize (Whsize_hp (hp)))
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#define Bhsize_hd(hd) (Bsize_wsize (Whsize_hd (hd)))
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#ifdef ARCH_BIG_ENDIAN
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#define Tag_val(val) (((unsigned char *) (val)) [-1])
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/* Also an l-value. */
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#define Tag_hp(hp) (((unsigned char *) (hp)) [sizeof(value)-1])
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/* Also an l-value. */
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#else
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#define Tag_val(val) (((unsigned char *) (val)) [-sizeof(value)])
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/* Also an l-value. */
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#define Tag_hp(hp) (((unsigned char *) (hp)) [0])
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/* Also an l-value. */
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#endif
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/* The lowest tag for blocks containing no value. */
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#define No_scan_tag 251
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/* 1- If tag < No_scan_tag : a tuple of fields. */
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/* Pointer to the first field. */
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#define Op_val(x) ((value *) (x))
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/* Fields are numbered from 0. */
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#define Field(x, i) (((value *)(x)) [i]) /* Also an l-value. */
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typedef int32 opcode_t;
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typedef opcode_t * code_t;
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/* NOTE: [Forward_tag] and [Infix_tag] must be just under
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[No_scan_tag], with [Infix_tag] the lower one.
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See [oldify_one] in minor_gc.c for more details.
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NOTE: Update stdlib/obj.ml whenever you change the tags.
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*/
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/* Forward_tag: forwarding pointer that the GC may silently shortcut.
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See stdlib/lazy.ml. */
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#define Forward_tag 250
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#define Forward_val(v) Field(v, 0)
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/* If tag == Infix_tag : an infix header inside a closure */
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/* Infix_tag must be odd so that the infix header is scanned as an integer */
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/* Infix_tag must be 1 modulo 4 and infix headers can only occur in blocks
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with tag Closure_tag (see compact.c). */
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#define Infix_tag 249
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#define Infix_offset_hd(hd) (Bosize_hd(hd))
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#define Infix_offset_val(v) Infix_offset_hd(Hd_val(v))
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/* Another special case: objects */
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#define Object_tag 248
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#define Class_val(val) Field((val), 0)
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#define Oid_val(val) Long_val(Field((val), 1))
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/* Special case of tuples of fields: closures */
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#define Closure_tag 247
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#define Code_val(val) (((code_t *) (val)) [0]) /* Also an l-value. */
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/* This tag is not special for the runtime, but it must not be used
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for any constructor. See stdlib/lazy.ml. */
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#define Lazy_tag 246
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/* Another special case: variants */
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CAMLextern value hash_variant(char * tag);
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/* 2- If tag >= No_scan_tag : a sequence of bytes. */
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/* Pointer to the first byte */
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#define Bp_val(v) ((char *) (v))
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#define Val_bp(p) ((value) (p))
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/* Bytes are numbered from 0. */
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#define Byte(x, i) (((char *) (x)) [i]) /* Also an l-value. */
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#define Byte_u(x, i) (((unsigned char *) (x)) [i]) /* Also an l-value. */
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/* Abstract things. Their contents is not traced by the GC; therefore they
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must not contain any [value].
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*/
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#define Abstract_tag 251
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/* Strings. */
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#define String_tag 252
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#define String_val(x) ((char *) Bp_val(x))
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CAMLextern mlsize_t string_length (value);
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/* Floating-point numbers. */
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#define Double_tag 253
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#define Double_wosize ((sizeof(double) / sizeof(value)))
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#ifndef ARCH_ALIGN_DOUBLE
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#define Double_val(v) (* (double *)(v))
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#define Store_double_val(v,d) (* (double *)(v) = (d))
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#else
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CAMLextern double Double_val (value);
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CAMLextern void Store_double_val (value,double);
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#endif
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/* Arrays of floating-point numbers. */
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#define Double_array_tag 254
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#define Double_field(v,i) Double_val((value)((double *)(v) + (i)))
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#define Store_double_field(v,i,d) do{ \
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mlsize_t caml__temp_i = (i); \
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double caml__temp_d = (d); \
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Store_double_val((value)((double *) v + caml__temp_i), caml__temp_d); \
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}while(0)
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/* Custom blocks. They contain a pointer to a "method suite"
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of functions (for finalization, comparison, hashing, etc)
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followed by raw data. The contents of custom blocks is not traced by
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the GC; therefore, they must not contain any [value].
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See [custom.h] for operations on method suites. */
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#define Custom_tag 255
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#define Data_custom_val(v) ((void *) &Field((v), 1))
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struct custom_operations; /* defined in [custom.h] */
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/* Int32.t, Int64.t and Nativeint.t are represented as custom blocks. */
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#define Int32_val(v) (*((int32 *) Data_custom_val(v)))
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#define Nativeint_val(v) (*((long *) Data_custom_val(v)))
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#ifndef ARCH_ALIGN_INT64
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#define Int64_val(v) (*((int64 *) Data_custom_val(v)))
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#else
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CAMLextern int64 Int64_val(value v);
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#endif
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/* 3- Atoms are 0-tuples. They are statically allocated once and for all. */
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CAMLextern header_t atom_table[];
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#define Atom(tag) (Val_hp (&(atom_table [(tag)])))
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/* Is_atom tests whether a well-formed block is statically allocated
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outside the heap. For the bytecode system, only zero-sized block (Atoms)
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fall in this class. For the native-code generator, data
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emitted by the code generator (as described in the table
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caml_data_segments) are also atoms. */
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#ifndef NATIVE_CODE
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#define Is_atom(v) ((v) >= Atom(0) && (v) <= Atom(255))
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#else
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CAMLextern char * static_data_start, * static_data_end;
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#define Is_atom(v) \
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((((char *)(v) >= static_data_start && (char *)(v) < static_data_end) || \
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((v) >= Atom(0) && (v) <= Atom(255))))
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#endif
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/* Booleans are integers 0 or 1 */
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#define Val_bool(x) Val_int((x) != 0)
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#define Bool_val(x) Int_val(x)
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#define Val_false Val_int(0)
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#define Val_true Val_int(1)
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#define Val_not(x) (Val_false + Val_true - (x))
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/* The unit value is 0 (tagged) */
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#define Val_unit Val_int(0)
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/* List constructors */
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#define Val_emptylist Val_int(0)
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#define Tag_cons 0
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/* The table of global identifiers */
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extern value global_data;
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#endif /* _mlvalues_ */
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