[14547] | 1 | /* Basic data types for Objective C. |
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| 2 | Copyright (C) 1998 Free Software Foundation, Inc. |
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| 3 | Contributed by Ovidiu Predescu. |
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| 4 | |
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| 5 | This file is part of GNU CC. |
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| 6 | |
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| 7 | GNU CC is free software; you can redistribute it and/or modify |
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| 8 | it under the terms of the GNU General Public License as published by |
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| 9 | the Free Software Foundation; either version 2, or (at your option) |
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| 10 | any later version. |
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| 11 | |
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| 12 | GNU CC is distributed in the hope that it will be useful, |
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| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 15 | GNU General Public License for more details. |
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| 16 | |
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| 17 | You should have received a copy of the GNU General Public License |
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| 18 | along with GNU CC; see the file COPYING. If not, write to |
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| 19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
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| 20 | Boston, MA 02111-1307, USA. */ |
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| 21 | |
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| 22 | /* As a special exception, if you link this library with files |
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| 23 | compiled with GCC to produce an executable, this does not cause |
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| 24 | the resulting executable to be covered by the GNU General Public License. |
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| 25 | This exception does not however invalidate any other reasons why |
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| 26 | the executable file might be covered by the GNU General Public License. */ |
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| 27 | |
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| 28 | #include "tconfig.h" |
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| 29 | #include "objc.h" |
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| 30 | #include "encoding.h" |
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| 31 | |
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| 32 | #include <assert.h> |
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| 33 | #include <string.h> |
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| 34 | |
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| 35 | #if OBJC_WITH_GC |
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| 36 | |
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| 37 | #include <gc.h> |
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| 38 | |
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| 39 | /* gc_typed.h uses the following but doesn't declare them */ |
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| 40 | typedef GC_word word; |
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| 41 | typedef GC_signed_word signed_word; |
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| 42 | |
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| 43 | #if BITS_PER_WORD == 32 |
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| 44 | # define LOGWL 5 |
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| 45 | # define modWORDSZ(n) ((n) & 0x1f) /* n mod size of word */ |
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| 46 | #endif |
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| 47 | |
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| 48 | #if BITS_PER_WORD == 64 |
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| 49 | # define LOGWL 6 |
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| 50 | # define modWORDSZ(n) ((n) & 0x3f) /* n mod size of word */ |
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| 51 | #endif |
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| 52 | |
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| 53 | #define divWORDSZ(n) ((n) >> LOGWL) /* divide n by size of word */ |
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| 54 | |
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| 55 | #include <gc_typed.h> |
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| 56 | |
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| 57 | /* The following functions set up in `mask` the corresponding pointers. |
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| 58 | The offset is incremented with the size of the type. */ |
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| 59 | |
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| 60 | #define ROUND(V, A) \ |
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| 61 | ({ typeof(V) __v=(V); typeof(A) __a=(A); \ |
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| 62 | __a*((__v+__a-1)/__a); }) |
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| 63 | |
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| 64 | #define SET_BIT_FOR_OFFSET(mask, offset) \ |
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| 65 | GC_set_bit(mask, offset / sizeof (void*)) |
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| 66 | |
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| 67 | /* Some prototypes */ |
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| 68 | static void |
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| 69 | __objc_gc_setup_struct (GC_bitmap mask, const char *type, int offset); |
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| 70 | static void |
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| 71 | __objc_gc_setup_union (GC_bitmap mask, const char *type, int offset); |
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| 72 | |
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| 73 | |
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| 74 | static void |
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| 75 | __objc_gc_setup_array (GC_bitmap mask, const char *type, int offset) |
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| 76 | { |
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| 77 | int i, len = atoi(type + 1); |
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| 78 | |
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| 79 | while (isdigit(*++type)) |
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| 80 | /* do nothing */; /* skip the size of the array */ |
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| 81 | |
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| 82 | switch (*type) { |
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| 83 | case _C_ARY_B: |
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| 84 | for (i = 0; i < len; i++) |
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| 85 | __objc_gc_setup_array (mask, type, offset); |
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| 86 | break; |
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| 87 | |
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| 88 | case _C_STRUCT_B: |
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| 89 | for (i = 0; i < len; i++) |
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| 90 | __objc_gc_setup_struct (mask, type, offset); |
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| 91 | break; |
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| 92 | |
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| 93 | case _C_UNION_B: |
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| 94 | for (i = 0; i < len; i++) |
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| 95 | __objc_gc_setup_union (mask, type, offset); |
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| 96 | break; |
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| 97 | |
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| 98 | default: |
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| 99 | break; |
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| 100 | } |
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| 101 | } |
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| 102 | |
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| 103 | static void |
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| 104 | __objc_gc_setup_struct (GC_bitmap mask, const char *type, int offset) |
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| 105 | { |
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| 106 | struct objc_struct_layout layout; |
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| 107 | unsigned int position; |
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| 108 | const char *mtype; |
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| 109 | |
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| 110 | objc_layout_structure (type, &layout); |
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| 111 | |
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| 112 | while (objc_layout_structure_next_member (&layout)) |
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| 113 | { |
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| 114 | BOOL gc_invisible = NO; |
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| 115 | |
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| 116 | objc_layout_structure_get_info (&layout, &position, NULL, &mtype); |
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| 117 | |
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| 118 | /* Skip the variable name */ |
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| 119 | if (*mtype == '"') |
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| 120 | { |
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| 121 | for (mtype++; *mtype++ != '"';) |
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| 122 | /* do nothing */; |
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| 123 | } |
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| 124 | |
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| 125 | if (*mtype == _C_GCINVISIBLE) |
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| 126 | { |
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| 127 | gc_invisible = YES; |
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| 128 | mtype++; |
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| 129 | } |
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| 130 | |
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| 131 | /* Add to position the offset of this structure */ |
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| 132 | position += offset; |
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| 133 | |
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| 134 | switch (*mtype) { |
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| 135 | case _C_ID: |
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| 136 | case _C_CLASS: |
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| 137 | case _C_SEL: |
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| 138 | case _C_PTR: |
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| 139 | case _C_CHARPTR: |
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| 140 | case _C_ATOM: |
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| 141 | if (!gc_invisible) |
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| 142 | SET_BIT_FOR_OFFSET(mask, position); |
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| 143 | break; |
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| 144 | |
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| 145 | case _C_ARY_B: |
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| 146 | __objc_gc_setup_array (mask, mtype, position); |
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| 147 | break; |
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| 148 | |
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| 149 | case _C_STRUCT_B: |
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| 150 | __objc_gc_setup_struct (mask, mtype, position); |
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| 151 | break; |
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| 152 | |
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| 153 | case _C_UNION_B: |
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| 154 | __objc_gc_setup_union (mask, mtype, position); |
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| 155 | break; |
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| 156 | |
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| 157 | default: |
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| 158 | break; |
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| 159 | } |
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| 160 | } |
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| 161 | } |
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| 162 | |
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| 163 | static void |
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| 164 | __objc_gc_setup_union (GC_bitmap mask, const char *type, int offset) |
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| 165 | { |
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| 166 | /* Sub-optimal, quick implementation: assume the union is made of |
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| 167 | pointers, set up the mask accordingly. */ |
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| 168 | |
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| 169 | int i, size, align; |
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| 170 | |
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| 171 | /* Skip the variable name */ |
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| 172 | if (*type == '"') |
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| 173 | { |
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| 174 | for (type++; *type++ != '"';) |
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| 175 | /* do nothing */; |
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| 176 | } |
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| 177 | |
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| 178 | size = objc_sizeof_type (type); |
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| 179 | align = objc_alignof_type (type); |
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| 180 | |
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| 181 | offset = ROUND(offset, align); |
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| 182 | for (i = 0; i < size; i += sizeof (void*)) |
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| 183 | { |
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| 184 | SET_BIT_FOR_OFFSET(mask, offset); |
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| 185 | offset += sizeof (void*); |
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| 186 | } |
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| 187 | } |
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| 188 | |
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| 189 | |
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| 190 | /* Iterates over the types in the structure that represents the class |
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| 191 | encoding and sets the bits in mask according to each ivar type. */ |
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| 192 | static void |
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| 193 | __objc_gc_type_description_from_type (GC_bitmap mask, const char *type) |
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| 194 | { |
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| 195 | struct objc_struct_layout layout; |
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| 196 | unsigned int offset, align; |
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| 197 | const char *ivar_type; |
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| 198 | |
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| 199 | objc_layout_structure (type, &layout); |
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| 200 | |
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| 201 | while (objc_layout_structure_next_member (&layout)) |
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| 202 | { |
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| 203 | BOOL gc_invisible = NO; |
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| 204 | |
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| 205 | objc_layout_structure_get_info (&layout, &offset, &align, &ivar_type); |
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| 206 | |
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| 207 | /* Skip the variable name */ |
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| 208 | if (*ivar_type == '"') |
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| 209 | { |
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| 210 | for (ivar_type++; *ivar_type++ != '"';) |
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| 211 | /* do nothing */; |
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| 212 | } |
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| 213 | |
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| 214 | if (*ivar_type == _C_GCINVISIBLE) |
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| 215 | { |
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| 216 | gc_invisible = YES; |
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| 217 | ivar_type++; |
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| 218 | } |
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| 219 | |
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| 220 | switch (*ivar_type) { |
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| 221 | case _C_ID: |
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| 222 | case _C_CLASS: |
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| 223 | case _C_SEL: |
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| 224 | case _C_PTR: |
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| 225 | case _C_CHARPTR: |
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| 226 | if (!gc_invisible) |
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| 227 | SET_BIT_FOR_OFFSET(mask, offset); |
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| 228 | break; |
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| 229 | |
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| 230 | case _C_ARY_B: |
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| 231 | __objc_gc_setup_array (mask, ivar_type, offset); |
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| 232 | break; |
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| 233 | |
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| 234 | case _C_STRUCT_B: |
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| 235 | __objc_gc_setup_struct (mask, ivar_type, offset); |
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| 236 | break; |
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| 237 | |
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| 238 | case _C_UNION_B: |
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| 239 | __objc_gc_setup_union (mask, ivar_type, offset); |
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| 240 | break; |
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| 241 | |
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| 242 | default: |
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| 243 | break; |
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| 244 | } |
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| 245 | } |
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| 246 | } |
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| 247 | |
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| 248 | /* Computes in *type the full type encoding of this class including |
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| 249 | its super classes. '*size' gives the total number of bytes allocated |
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| 250 | into *type, '*current' the number of bytes used so far by the |
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| 251 | encoding. */ |
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| 252 | static void |
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| 253 | __objc_class_structure_encoding (Class class, char **type, int *size, |
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| 254 | int *current) |
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| 255 | { |
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| 256 | int i, ivar_count; |
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| 257 | struct objc_ivar_list* ivars; |
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| 258 | |
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| 259 | if (!class) |
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| 260 | { |
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| 261 | strcat (*type, "{"); |
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| 262 | *current++; |
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| 263 | return; |
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| 264 | } |
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| 265 | |
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| 266 | /* Add the type encodings of the super classes */ |
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| 267 | __objc_class_structure_encoding (class->super_class, type, size, current); |
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| 268 | |
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| 269 | ivars = class->ivars; |
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| 270 | if (!ivars) |
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| 271 | return; |
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| 272 | |
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| 273 | ivar_count = ivars->ivar_count; |
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| 274 | |
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| 275 | for (i = 0; i < ivar_count; i++) |
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| 276 | { |
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| 277 | struct objc_ivar *ivar = &(ivars->ivar_list[i]); |
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| 278 | const char *ivar_type = ivar->ivar_type; |
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| 279 | int len = strlen (ivar_type); |
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| 280 | |
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| 281 | if (*current + len + 1 >= *size) |
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| 282 | { |
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| 283 | /* Increase the size of the encoding string so that it |
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| 284 | contains this ivar's type. */ |
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| 285 | *size = ROUND(*current + len + 1, 10); |
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| 286 | *type = objc_realloc (*type, *size); |
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| 287 | } |
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| 288 | strcat (*type + *current, ivar_type); |
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| 289 | *current += len; |
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| 290 | } |
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| 291 | } |
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| 292 | |
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| 293 | |
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| 294 | /* Allocates the memory that will hold the type description for class |
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| 295 | and calls the __objc_class_structure_encoding that generates this |
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| 296 | value. */ |
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| 297 | void |
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| 298 | __objc_generate_gc_type_description (Class class) |
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| 299 | { |
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| 300 | GC_bitmap mask; |
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| 301 | int bits_no, size; |
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| 302 | int type_size = 10, current; |
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| 303 | char *class_structure_type; |
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| 304 | |
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| 305 | if (!CLS_ISCLASS(class)) |
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| 306 | return; |
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| 307 | |
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| 308 | /* We have to create a mask in which each bit counts for a pointer member. |
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| 309 | We take into consideration all the non-pointer instance variables and we |
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| 310 | round them up to the alignment. */ |
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| 311 | |
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| 312 | /* The number of bits in the mask is the size of an instance in bytes divided |
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| 313 | by the size of a pointer. */ |
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| 314 | bits_no = (ROUND(class_get_instance_size (class), sizeof(void*)) |
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| 315 | / sizeof (void*)); |
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| 316 | size = ROUND(bits_no, BITS_PER_WORD) / BITS_PER_WORD; |
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| 317 | mask = objc_atomic_malloc (size * sizeof (int)); |
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| 318 | memset (mask, 0, size * sizeof (int)); |
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| 319 | |
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| 320 | class_structure_type = objc_atomic_malloc (type_size); |
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| 321 | *class_structure_type = current = 0; |
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| 322 | __objc_class_structure_encoding (class, &class_structure_type, |
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| 323 | &type_size, ¤t); |
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| 324 | if (current + 1 == type_size) |
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| 325 | class_structure_type = objc_realloc (class_structure_type, ++type_size); |
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| 326 | strcat (class_structure_type + current, "}"); |
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[18473] | 327 | #ifdef DEBUG |
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| 328 | printf ("type description for '%s' is %s\n", class->name, class_structure_type); |
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| 329 | #endif |
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[14547] | 330 | |
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| 331 | __objc_gc_type_description_from_type (mask, class_structure_type); |
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| 332 | objc_free (class_structure_type); |
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| 333 | |
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| 334 | #ifdef DEBUG |
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| 335 | printf (" mask for '%s', type '%s' (bits %d, mask size %d) is:", |
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| 336 | class_structure_type, class->name, bits_no, size); |
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| 337 | { |
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| 338 | int i; |
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| 339 | for (i = 0; i < size; i++) |
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| 340 | printf (" %lx", mask[i]); |
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| 341 | } |
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| 342 | puts (""); |
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| 343 | #endif |
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| 344 | |
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| 345 | class->gc_object_type = (void*)GC_make_descriptor (mask, bits_no); |
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| 346 | } |
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| 347 | |
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| 348 | |
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| 349 | /* Returns YES if type denotes a pointer type, NO otherwise */ |
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| 350 | static inline BOOL |
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| 351 | __objc_ivar_pointer (const char *type) |
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| 352 | { |
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| 353 | type = objc_skip_type_qualifiers (type); |
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| 354 | |
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| 355 | return (*type == _C_ID |
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| 356 | || *type == _C_CLASS |
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| 357 | || *type == _C_SEL |
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| 358 | || *type == _C_PTR |
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| 359 | || *type == _C_CHARPTR |
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| 360 | || *type == _C_ATOM); |
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| 361 | } |
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| 362 | |
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| 363 | |
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| 364 | /* Mark the instance variable whose name is given by ivarname as a |
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| 365 | weak pointer (a pointer hidden to the garbage collector) if |
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| 366 | gc_invisible is true. If gc_invisible is false it unmarks the |
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| 367 | instance variable and makes it a normal pointer, visible to the |
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| 368 | garbage collector. |
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| 369 | |
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| 370 | This operation only makes sense on instance variables that are |
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| 371 | pointers. */ |
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| 372 | void |
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| 373 | class_ivar_set_gcinvisible (Class class, const char* ivarname, |
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| 374 | BOOL gc_invisible) |
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| 375 | { |
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| 376 | int i, ivar_count; |
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| 377 | struct objc_ivar_list* ivars; |
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| 378 | |
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| 379 | if (!class || !ivarname) |
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| 380 | return; |
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| 381 | |
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| 382 | ivars = class->ivars; |
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| 383 | if (!ivars) |
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| 384 | return; |
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| 385 | |
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| 386 | ivar_count = ivars->ivar_count; |
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| 387 | |
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| 388 | for (i = 0; i < ivar_count; i++) |
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| 389 | { |
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| 390 | struct objc_ivar *ivar = &(ivars->ivar_list[i]); |
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| 391 | const char *type; |
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| 392 | |
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| 393 | if (!ivar->ivar_name || strcmp (ivar->ivar_name, ivarname)) |
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| 394 | continue; |
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| 395 | |
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| 396 | assert (ivar->ivar_type); |
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| 397 | type = ivar->ivar_type; |
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| 398 | |
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| 399 | /* Skip the variable name */ |
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| 400 | if (*type == '"') |
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| 401 | { |
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| 402 | for (type++; *type++ != '"';) |
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| 403 | /* do nothing */; |
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| 404 | } |
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| 405 | |
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| 406 | if (*type == _C_GCINVISIBLE) |
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| 407 | { |
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| 408 | char *new_type; |
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| 409 | |
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| 410 | if (gc_invisible || !__objc_ivar_pointer (type)) |
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| 411 | return; /* The type of the variable already matches the |
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| 412 | requested gc_invisible type */ |
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| 413 | |
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| 414 | /* The variable is gc_invisible and we have to reverse it */ |
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| 415 | new_type = objc_atomic_malloc (strlen (ivar->ivar_type)); |
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| 416 | strncpy (new_type, ivar->ivar_type, |
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| 417 | (size_t)(type - ivar->ivar_type)); |
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| 418 | strcat (new_type, type + 1); |
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| 419 | ivar->ivar_type = new_type; |
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| 420 | } |
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| 421 | else |
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| 422 | { |
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| 423 | char *new_type; |
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| 424 | |
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| 425 | if (!gc_invisible || !__objc_ivar_pointer (type)) |
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| 426 | return; /* The type of the variable already matches the |
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| 427 | requested gc_invisible type */ |
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| 428 | |
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| 429 | /* The variable is gc visible and we have to make it gc_invisible */ |
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| 430 | new_type = objc_malloc (strlen (ivar->ivar_type) + 2); |
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| 431 | strncpy (new_type, ivar->ivar_type, |
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| 432 | (size_t)(type - ivar->ivar_type)); |
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| 433 | strcat (new_type, "!"); |
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| 434 | strcat (new_type, type); |
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| 435 | ivar->ivar_type = new_type; |
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| 436 | } |
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| 437 | |
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| 438 | __objc_generate_gc_type_description (class); |
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| 439 | return; |
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| 440 | } |
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| 441 | |
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| 442 | /* Search the instance variable in the superclasses */ |
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| 443 | class_ivar_set_gcinvisible (class->super_class, ivarname, gc_invisible); |
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| 444 | } |
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| 445 | |
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| 446 | #else /* !OBJC_WITH_GC */ |
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| 447 | |
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| 448 | void |
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| 449 | __objc_generate_gc_type_description (Class class) |
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| 450 | { |
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| 451 | } |
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| 452 | |
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| 453 | void class_ivar_set_gcinvisible (Class class, |
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| 454 | const char* ivarname, |
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| 455 | BOOL gc_invisible) |
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| 456 | { |
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| 457 | } |
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| 458 | |
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| 459 | #endif /* OBJC_WITH_GC */ |
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