1 | /* GNU Objective C Runtime message lookup |
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2 | Copyright (C) 1993, 1995 Free Software Foundation, Inc. |
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3 | Contributed by Kresten Krab Thorup |
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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 it under the |
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8 | terms of the GNU General Public License as published by the Free Software |
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9 | Foundation; either version 2, or (at your option) any later version. |
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10 | |
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11 | GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY |
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12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
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13 | FOR A PARTICULAR PURPOSE. See the GNU General Public License for more |
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14 | details. |
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15 | |
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16 | You should have received a copy of the GNU General Public License along with |
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17 | GNU CC; see the file COPYING. If not, write to the Free Software |
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18 | Foundation, 59 Temple Place - Suite 330, |
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19 | Boston, MA 02111-1307, USA. */ |
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20 | |
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21 | /* As a special exception, if you link this library with files compiled with |
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22 | GCC to produce an executable, this does not cause the resulting executable |
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23 | to be covered by the GNU General Public License. This exception does not |
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24 | however invalidate any other reasons why the executable file might be |
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25 | covered by the GNU General Public License. */ |
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26 | |
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27 | #include "../tconfig.h" |
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28 | #include "runtime.h" |
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29 | #include "sarray.h" |
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30 | #include "encoding.h" |
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31 | |
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32 | /* this is how we hack STRUCT_VALUE to be 1 or 0 */ |
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33 | #define gen_rtx(args...) 1 |
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34 | #define rtx int |
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35 | |
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36 | #if STRUCT_VALUE == 0 |
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37 | #define INVISIBLE_STRUCT_RETURN 1 |
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38 | #else |
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39 | #define INVISIBLE_STRUCT_RETURN 0 |
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40 | #endif |
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41 | |
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42 | /* The uninstalled dispatch table */ |
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43 | struct sarray* __objc_uninstalled_dtable = 0; |
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44 | |
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45 | /* Send +initialize to class */ |
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46 | static void __objc_send_initialize(Class); |
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47 | |
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48 | static void __objc_install_dispatch_table_for_class (Class); |
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49 | |
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50 | /* Forward declare some functions */ |
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51 | static void __objc_init_install_dtable(id, SEL); |
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52 | static id __objc_word_forward(id, SEL, ...); |
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53 | typedef struct { id many[8]; } __big; |
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54 | #if INVISIBLE_STRUCT_RETURN |
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55 | static __big |
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56 | #else |
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57 | static id |
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58 | #endif |
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59 | __objc_block_forward(id, SEL, ...); |
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60 | static Method_t search_for_method_in_hierarchy (Class class, SEL sel); |
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61 | static Method_t search_for_method_in_list(MethodList_t list, SEL op); |
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62 | id nil_method(id, SEL, ...); |
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63 | |
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64 | id |
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65 | nil_method(id receiver, SEL op, ...) |
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66 | { |
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67 | return receiver; |
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68 | } |
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69 | |
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70 | /* Given a class and selector, return the selector's implementation. */ |
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71 | __inline__ |
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72 | IMP |
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73 | get_imp (Class class, SEL sel) |
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74 | { |
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75 | IMP impl; |
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76 | void* res = sarray_get (class->dtable, (size_t) sel->sel_id); |
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77 | if(res == __objc_init_install_dtable) |
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78 | { |
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79 | __objc_install_dispatch_table_for_class (class); |
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80 | res = sarray_get (class->dtable, (size_t) sel->sel_id); |
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81 | } |
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82 | if (res == 0) |
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83 | { |
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84 | const char *t = sel->sel_types; |
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85 | if (t && (*t == '[' || *t == '(' || *t == '{')) |
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86 | res = (IMP)__objc_block_forward; |
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87 | else |
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88 | res = (IMP)__objc_word_forward; |
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89 | } |
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90 | return res; |
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91 | } |
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92 | |
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93 | __inline__ BOOL |
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94 | __objc_responds_to (id object, SEL sel) |
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95 | { |
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96 | void* res = sarray_get (object->class_pointer->dtable, (size_t) sel->sel_id); |
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97 | if(res == __objc_init_install_dtable) |
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98 | { |
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99 | __objc_install_dispatch_table_for_class (object->class_pointer); |
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100 | res = sarray_get (object->class_pointer->dtable, (size_t) sel->sel_id); |
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101 | } |
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102 | return (res != 0); |
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103 | } |
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104 | |
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105 | /* This is the lookup function. All entries in the table are either a |
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106 | valid method *or* one of `__objc_missing_method' which calls |
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107 | forward:: etc, or `__objc_init_install_dtable' which installs the |
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108 | real dtable */ |
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109 | __inline__ IMP |
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110 | objc_msg_lookup(id receiver, SEL op) |
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111 | { |
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112 | IMP result; |
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113 | if(receiver) |
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114 | { |
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115 | result = sarray_get(receiver->class_pointer->dtable, (sidx)op->sel_id); |
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116 | if (result == 0) |
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117 | { |
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118 | const char *t = op->sel_types; |
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119 | if (t && (*t == '[' || *t == '(' || *t == '{')) |
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120 | result = (IMP)__objc_block_forward; |
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121 | else |
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122 | result = (IMP)__objc_word_forward; |
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123 | } |
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124 | return result; |
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125 | } |
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126 | else |
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127 | return nil_method; |
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128 | } |
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129 | |
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130 | IMP |
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131 | objc_msg_lookup_super (Super_t super, SEL sel) |
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132 | { |
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133 | if (super->self) |
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134 | return get_imp (super->class, sel); |
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135 | else |
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136 | return nil_method; |
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137 | } |
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138 | |
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139 | int method_get_sizeof_arguments (Method*); |
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140 | |
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141 | retval_t |
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142 | objc_msg_sendv(id object, SEL op, arglist_t arg_frame) |
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143 | { |
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144 | Method* m = class_get_instance_method(object->class_pointer, op); |
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145 | const char *type; |
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146 | *((id*)method_get_first_argument (m, arg_frame, &type)) = object; |
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147 | *((SEL*)method_get_next_argument (arg_frame, &type)) = op; |
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148 | return __builtin_apply((apply_t)m->method_imp, |
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149 | arg_frame, |
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150 | method_get_sizeof_arguments (m)); |
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151 | } |
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152 | |
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153 | void __objc_init_dispatch_tables() |
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154 | { |
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155 | __objc_uninstalled_dtable |
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156 | = sarray_new(200, __objc_init_install_dtable); |
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157 | } |
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158 | |
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159 | /* This one is a bit hairy. This function is installed in the |
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160 | premature dispatch table, and thus called once for each class, |
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161 | namely when the very first message is send to it. */ |
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162 | |
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163 | static void __objc_init_install_dtable(id receiver, SEL op) |
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164 | { |
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165 | __label__ already_initialized; |
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166 | IMP imp; |
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167 | void* args; |
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168 | void* result; |
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169 | |
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170 | /* This may happen, if the programmer has taken the address of a |
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171 | method before the dtable was initialized... too bad for him! */ |
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172 | if(receiver->class_pointer->dtable != __objc_uninstalled_dtable) |
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173 | goto already_initialized; |
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174 | |
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175 | if(CLS_ISCLASS(receiver->class_pointer)) |
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176 | { |
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177 | /* receiver is an ordinary object */ |
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178 | assert(CLS_ISCLASS(receiver->class_pointer)); |
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179 | |
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180 | /* install instance methods table */ |
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181 | __objc_install_dispatch_table_for_class (receiver->class_pointer); |
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182 | |
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183 | /* call +initialize -- this will in turn install the factory |
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184 | dispatch table if not already done :-) */ |
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185 | __objc_send_initialize(receiver->class_pointer); |
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186 | } |
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187 | else |
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188 | { |
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189 | /* receiver is a class object */ |
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190 | assert(CLS_ISCLASS((Class)receiver)); |
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191 | assert(CLS_ISMETA(receiver->class_pointer)); |
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192 | |
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193 | /* Install real dtable for factory methods */ |
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194 | __objc_install_dispatch_table_for_class (receiver->class_pointer); |
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195 | |
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196 | if (strcmp (sel_get_name (op), "initialize")) |
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197 | __objc_send_initialize((Class)receiver); |
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198 | else |
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199 | CLS_SETINITIALIZED((Class)receiver); |
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200 | } |
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201 | |
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202 | already_initialized: |
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203 | |
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204 | /* Get real method for this in newly installed dtable */ |
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205 | imp = get_imp(receiver->class_pointer, op); |
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206 | |
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207 | args = __builtin_apply_args(); |
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208 | result = __builtin_apply((apply_t)imp, args, 96); |
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209 | if (result) |
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210 | __builtin_return (result); |
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211 | else |
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212 | return; |
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213 | |
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214 | } |
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215 | |
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216 | /* Install dummy table for class which causes the first message to |
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217 | that class (or instances hereof) to be initialized properly */ |
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218 | void __objc_install_premature_dtable(Class class) |
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219 | { |
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220 | assert(__objc_uninstalled_dtable); |
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221 | class->dtable = __objc_uninstalled_dtable; |
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222 | } |
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223 | |
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224 | /* Send +initialize to class if not already done */ |
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225 | static void __objc_send_initialize(Class class) |
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226 | { |
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227 | /* This *must* be a class object */ |
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228 | assert(CLS_ISCLASS(class)); |
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229 | assert(!CLS_ISMETA(class)); |
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230 | |
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231 | if (!CLS_ISINITIALIZED(class)) |
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232 | { |
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233 | CLS_SETINITIALIZED(class); |
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234 | CLS_SETINITIALIZED(class->class_pointer); |
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235 | |
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236 | if(class->super_class) |
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237 | __objc_send_initialize(class->super_class); |
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238 | |
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239 | { |
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240 | SEL op = sel_register_name ("initialize"); |
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241 | Class tmpclass = class; |
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242 | IMP imp = 0; |
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243 | |
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244 | while (!imp && tmpclass) { |
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245 | MethodList_t method_list = tmpclass->class_pointer->methods; |
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246 | |
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247 | while(!imp && method_list) { |
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248 | int i; |
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249 | Method_t method; |
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250 | |
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251 | for (i=0;i<method_list->method_count;i++) { |
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252 | method = &(method_list->method_list[i]); |
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253 | if (method->method_name->sel_id == op->sel_id) { |
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254 | imp = method->method_imp; |
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255 | break; |
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256 | } |
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257 | } |
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258 | |
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259 | method_list = method_list->method_next; |
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260 | |
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261 | } |
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262 | |
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263 | tmpclass = tmpclass->super_class; |
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264 | } |
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265 | if (imp) |
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266 | (*imp)((id)class, op); |
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267 | |
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268 | } |
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269 | } |
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270 | } |
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271 | |
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272 | static void |
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273 | __objc_install_dispatch_table_for_class (Class class) |
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274 | { |
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275 | Class super; |
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276 | MethodList_t mlist; |
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277 | int counter; |
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278 | |
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279 | /* If the class has not yet had it's class links resolved, we must |
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280 | re-compute all class links */ |
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281 | if(!CLS_ISRESOLV(class)) |
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282 | __objc_resolve_class_links(); |
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283 | |
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284 | super = class->super_class; |
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285 | |
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286 | if (super != 0 && (super->dtable == __objc_uninstalled_dtable)) |
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287 | __objc_install_dispatch_table_for_class (super); |
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288 | |
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289 | /* Allocate dtable if necessary */ |
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290 | if (super == 0) |
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291 | { |
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292 | class->dtable = sarray_new (__objc_selector_max_index, 0); |
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293 | } |
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294 | else |
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295 | class->dtable = sarray_lazy_copy (super->dtable); |
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296 | |
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297 | for (mlist = class->methods; mlist; mlist = mlist->method_next) |
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298 | { |
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299 | counter = mlist->method_count - 1; |
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300 | while (counter >= 0) |
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301 | { |
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302 | Method_t method = &(mlist->method_list[counter]); |
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303 | sarray_at_put_safe (class->dtable, |
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304 | (sidx) method->method_name->sel_id, |
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305 | method->method_imp); |
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306 | counter -= 1; |
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307 | } |
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308 | } |
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309 | } |
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310 | |
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311 | void __objc_update_dispatch_table_for_class (Class class) |
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312 | { |
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313 | Class next; |
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314 | |
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315 | /* not yet installed -- skip it */ |
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316 | if (class->dtable == __objc_uninstalled_dtable) |
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317 | return; |
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318 | |
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319 | sarray_free (class->dtable); /* release memory */ |
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320 | __objc_install_premature_dtable (class); /* someone might require it... */ |
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321 | __objc_install_dispatch_table_for_class (class); /* could have been lazy... */ |
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322 | |
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323 | if (class->subclass_list) /* Traverse subclasses */ |
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324 | for (next = class->subclass_list; next; next = next->sibling_class) |
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325 | __objc_update_dispatch_table_for_class (next); |
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326 | |
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327 | } |
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328 | |
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329 | |
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330 | /* This function adds a method list to a class. This function is |
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331 | typically called by another function specific to the run-time. As |
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332 | such this function does not worry about thread safe issued. |
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333 | |
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334 | This one is only called for categories. Class objects have their |
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335 | methods installed right away, and their selectors are made into |
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336 | SEL's by the function __objc_register_selectors_from_class. */ |
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337 | void |
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338 | class_add_method_list (Class class, MethodList_t list) |
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339 | { |
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340 | int i; |
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341 | static SEL initialize_sel = 0; |
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342 | if (!initialize_sel) |
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343 | initialize_sel = sel_register_name ("initialize"); |
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344 | |
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345 | /* Passing of a linked list is not allowed. Do multiple calls. */ |
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346 | assert (!list->method_next); |
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347 | |
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348 | /* Check for duplicates. */ |
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349 | for (i = 0; i < list->method_count; ++i) |
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350 | { |
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351 | Method_t method = &list->method_list[i]; |
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352 | |
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353 | if (method->method_name) /* Sometimes these are NULL */ |
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354 | { |
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355 | /* This is where selector names are transmogrified to SEL's */ |
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356 | method->method_name = |
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357 | sel_register_typed_name ((const char*)method->method_name, |
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358 | method->method_types); |
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359 | |
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360 | if (search_for_method_in_list (class->methods, method->method_name) |
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361 | && method->method_name->sel_id != initialize_sel->sel_id) |
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362 | { |
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363 | /* Duplication. Print a error message an change the method name |
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364 | to NULL. */ |
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365 | fprintf (stderr, "attempt to add a existing method: %s\n", |
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366 | sel_get_name(method->method_name)); |
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367 | method->method_name = 0; |
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368 | } |
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369 | } |
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370 | } |
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371 | |
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372 | /* Add the methods to the class's method list. */ |
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373 | list->method_next = class->methods; |
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374 | class->methods = list; |
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375 | } |
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376 | |
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377 | |
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378 | Method_t |
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379 | class_get_instance_method(Class class, SEL op) |
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380 | { |
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381 | return search_for_method_in_hierarchy(class, op); |
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382 | } |
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383 | |
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384 | Method_t |
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385 | class_get_class_method(MetaClass class, SEL op) |
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386 | { |
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387 | return search_for_method_in_hierarchy(class, op); |
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388 | } |
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389 | |
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390 | |
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391 | /* Search for a method starting from the current class up its hierarchy. |
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392 | Return a pointer to the method's method structure if found. NULL |
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393 | otherwise. */ |
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394 | |
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395 | static Method_t |
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396 | search_for_method_in_hierarchy (Class cls, SEL sel) |
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397 | { |
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398 | Method_t method = NULL; |
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399 | Class class; |
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400 | |
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401 | if (! sel_is_mapped (sel)) |
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402 | return NULL; |
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403 | |
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404 | /* Scan the method list of the class. If the method isn't found in the |
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405 | list then step to its super class. */ |
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406 | for (class = cls; ((! method) && class); class = class->super_class) |
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407 | method = search_for_method_in_list (class->methods, sel); |
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408 | |
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409 | return method; |
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410 | } |
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411 | |
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412 | |
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413 | |
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414 | /* Given a linked list of method and a method's name. Search for the named |
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415 | method's method structure. Return a pointer to the method's method |
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416 | structure if found. NULL otherwise. */ |
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417 | static Method_t |
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418 | search_for_method_in_list (MethodList_t list, SEL op) |
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419 | { |
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420 | MethodList_t method_list = list; |
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421 | |
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422 | if (! sel_is_mapped (op)) |
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423 | return NULL; |
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424 | |
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425 | /* If not found then we'll search the list. */ |
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426 | while (method_list) |
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427 | { |
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428 | int i; |
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429 | |
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430 | /* Search the method list. */ |
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431 | for (i = 0; i < method_list->method_count; ++i) |
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432 | { |
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433 | Method_t method = &method_list->method_list[i]; |
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434 | |
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435 | if (method->method_name) |
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436 | if (method->method_name->sel_id == op->sel_id) |
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437 | return method; |
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438 | } |
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439 | |
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440 | /* The method wasn't found. Follow the link to the next list of |
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441 | methods. */ |
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442 | method_list = method_list->method_next; |
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443 | } |
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444 | |
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445 | return NULL; |
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446 | } |
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447 | |
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448 | static retval_t __objc_forward (id object, SEL sel, arglist_t args); |
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449 | |
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450 | static id |
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451 | __objc_word_forward (id rcv, SEL op, ...) |
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452 | { |
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453 | void *args, *res; |
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454 | |
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455 | args = __builtin_apply_args (); |
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456 | res = __objc_forward (rcv, op, args); |
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457 | if (res) |
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458 | __builtin_return (res); |
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459 | else |
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460 | return res; |
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461 | } |
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462 | |
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463 | #if INVISIBLE_STRUCT_RETURN |
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464 | static __big |
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465 | #else |
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466 | static id |
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467 | #endif |
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468 | __objc_block_forward (id rcv, SEL op, ...) |
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469 | { |
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470 | void *args, *res; |
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471 | |
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472 | args = __builtin_apply_args (); |
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473 | res = __objc_forward (rcv, op, args); |
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474 | if (res) |
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475 | __builtin_return (res); |
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476 | } |
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477 | |
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478 | |
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479 | /* This function is installed in the dispatch table for all methods which are |
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480 | not implemented. Thus, it is called when a selector is not recognized. */ |
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481 | static retval_t |
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482 | __objc_forward (id object, SEL sel, arglist_t args) |
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483 | { |
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484 | IMP imp; |
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485 | static SEL frwd_sel = 0; |
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486 | SEL err_sel; |
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487 | |
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488 | /* first try if the object understands forward:: */ |
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489 | if (!frwd_sel) |
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490 | frwd_sel = sel_get_any_uid("forward::"); |
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491 | |
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492 | if (__objc_responds_to (object, frwd_sel)) |
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493 | { |
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494 | imp = get_imp(object->class_pointer, frwd_sel); |
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495 | return (*imp)(object, frwd_sel, sel, args); |
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496 | } |
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497 | |
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498 | /* If the object recognizes the doesNotRecognize: method then we're going |
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499 | to send it. */ |
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500 | err_sel = sel_get_any_uid ("doesNotRecognize:"); |
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501 | if (__objc_responds_to (object, err_sel)) |
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502 | { |
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503 | imp = get_imp (object->class_pointer, err_sel); |
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504 | return (*imp) (object, err_sel, sel); |
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505 | } |
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506 | |
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507 | /* The object doesn't recognize the method. Check for responding to |
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508 | error:. If it does then sent it. */ |
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509 | { |
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510 | size_t strlen (const char*); |
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511 | char msg[256 + strlen ((const char*)sel_get_name (sel)) |
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512 | + strlen ((const char*)object->class_pointer->name)]; |
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513 | |
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514 | sprintf (msg, "(%s) %s does not recognize %s", |
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515 | (CLS_ISMETA(object->class_pointer) |
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516 | ? "class" |
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517 | : "instance" ), |
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518 | object->class_pointer->name, sel_get_name (sel)); |
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519 | |
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520 | err_sel = sel_get_any_uid ("error:"); |
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521 | if (__objc_responds_to (object, err_sel)) |
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522 | { |
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523 | imp = get_imp (object->class_pointer, err_sel); |
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524 | return (*imp) (object, sel_get_any_uid ("error:"), msg); |
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525 | } |
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526 | |
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527 | /* The object doesn't respond to doesNotRecognize: or error:; Therefore, |
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528 | a default action is taken. */ |
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529 | fprintf (stderr, "fatal: %s\n", msg); |
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530 | abort (); |
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531 | } |
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532 | } |
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533 | |
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534 | void __objc_print_dtable_stats() |
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535 | { |
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536 | int total = 0; |
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537 | printf("memory usage: (%s)\n", |
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538 | #ifdef OBJC_SPARSE2 |
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539 | "2-level sparse arrays" |
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540 | #else |
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541 | "3-level sparse arrays" |
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542 | #endif |
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543 | ); |
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544 | |
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545 | printf("arrays: %d = %ld bytes\n", narrays, (int)narrays*sizeof(struct sarray)); |
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546 | total += narrays*sizeof(struct sarray); |
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547 | printf("buckets: %d = %ld bytes\n", nbuckets, (int)nbuckets*sizeof(struct sbucket)); |
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548 | total += nbuckets*sizeof(struct sbucket); |
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549 | |
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550 | printf("idxtables: %d = %ld bytes\n", idxsize, (int)idxsize*sizeof(void*)); |
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551 | total += idxsize*sizeof(void*); |
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552 | printf("-----------------------------------\n"); |
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553 | printf("total: %d bytes\n", total); |
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554 | printf("===================================\n"); |
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555 | } |
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556 | |
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557 | |
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558 | |
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