mono/metadata/abi-details.h

   1 /**
   2  * \file
   3  * Copyright 2014 Xamarin Inc
   4  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   5  */
   6 #ifndef __MONO_METADATA_ABI_DETAILS_H__
   7 #define __MONO_METADATA_ABI_DETAILS_H__
   8
   9 #include <config.h>
  10 #include <glib.h>
  11
  12 /*
  13  * This file defines macros to compute sizes/alignments/field offsets which depend on
  14  * the ABI. It is needed during cross compiling since the generated code needs to
  15  * contain offsets which correspond to the ABI of the target, not the host.
  16  * It defines the following macros:
  17  * - MONO_ABI_SIZEOF(type) for every basic type
  18  * - MONO_ABI_ALIGNOF(type) for every basic type
  19  * - MONO_STRUCT_OFFSET(struct, field) for various runtime structures
  20  * When not cross compiling, these correspond to the host ABI (i.e. sizeof/offsetof).
  21  * When cross compiling, these are defined in a generated header file which is
  22  * generated by the offsets tool in tools/offsets-tool. The name of the file
  23  * is given by the --with-cross-offsets= configure argument.
  24  */
  25
  26 typedef enum {
  27         MONO_ALIGN_gint8,
  28         MONO_ALIGN_gint16,
  29         MONO_ALIGN_gint32,
  30         MONO_ALIGN_gint64,
  31         MONO_ALIGN_float,
  32         MONO_ALIGN_double,
  33         MONO_ALIGN_gpointer,
  34         MONO_ALIGN_COUNT
  35 } CoreTypeAlign;
  36
  37 int mono_abi_alignment (CoreTypeAlign type);
  38
  39 #define MONO_ABI_ALIGNOF(type) mono_abi_alignment (MONO_ALIGN_ ## type)
  40 #define MONO_ABI_SIZEOF(type) (MONO_STRUCT_SIZE (type))
  41 #define MONO_CURRENT_ABI_SIZEOF(type) ((int)sizeof(type))
  42
  43 #undef DECL_OFFSET2
  44 #define DECL_OFFSET(struct,field) MONO_OFFSET_ ## struct ## _ ## field = -1,
  45 #define DECL_OFFSET2(struct,field,offset) MONO_OFFSET_ ## struct ## _ ## field = offset,
  46 #define DECL_ALIGN2(type,size)
  47 #define DECL_SIZE(type) MONO_SIZEOF_ ##type = -1,
  48 #define DECL_SIZE2(type,size) MONO_SIZEOF_ ##type = size,
  49
  50
  51 enum {
  52 #include "object-offsets.h"
  53 };
  54
  55 #ifdef USED_CROSS_COMPILER_OFFSETS
  56 #define MONO_STRUCT_OFFSET(struct,field) MONO_OFFSET_ ## struct ## _ ## field
  57 #define MONO_STRUCT_OFFSET_CONSTANT(struct,field) MONO_STRUCT_OFFSET(struct,field)
  58 #define MONO_STRUCT_SIZE(struct) MONO_SIZEOF_ ## struct
  59 #else
  60 /* This macro is expanding to something that uses the comma operator in C [0].
  61  * The first part introduces an expression that uses the `MONO_OFFSET_*`
  62  * define. The result isn't used, but it forces the compiler to bail out if the
  63  * define doesn't exist; this happens when we forgot to add an entry in
  64  * `object-offsets.h` accordingly.
  65  *
  66  * [0] https://en.wikipedia.org/wiki/Comma_operator
  67  */
  68 #define MONO_STRUCT_OFFSET(struct,field) (MONO_OFFSET_ ## struct ## _ ## field == -1, G_STRUCT_OFFSET (struct,field))
  69 #define MONO_STRUCT_OFFSET_CONSTANT(struct,field) G_STRUCT_OFFSET (struct,field)
  70 #define MONO_STRUCT_SIZE(struct) (MONO_SIZEOF_ ## struct == -1, (int)sizeof(struct))
  71 #endif
  72
  73 // #define MONO_SIZEOF_MonoObject (2 * MONO_ABI_SIZEOF(gpointer))
  74 #define MONO_SIZEOF_MonoObject (2 * MONO_SIZEOF_gpointer)
  75 #endif