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1 /* |
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2 * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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20 * CA 95054 USA or visit www.sun.com if you need additional information or |
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21 * have any questions. |
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22 * |
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23 */ |
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24 |
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25 // ciObject |
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26 // |
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27 // This class represents an oop in the HotSpot virtual machine. |
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28 // Its subclasses are structured in a hierarchy which mirrors |
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29 // an aggregate of the VM's oop and klass hierarchies (see |
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30 // oopHierarchy.hpp). Each instance of ciObject holds a handle |
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31 // to a corresponding oop on the VM side and provides routines |
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32 // for accessing the information in its oop. By using the ciObject |
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33 // hierarchy for accessing oops in the VM, the compiler ensures |
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34 // that it is safe with respect to garbage collection; that is, |
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35 // GC and compilation can proceed independently without |
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36 // interference. |
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37 // |
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38 // Within the VM, the oop and klass hierarchies are separate. |
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39 // The compiler interface does not preserve this separation -- |
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40 // the distinction between `klassOop' and `Klass' are not |
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41 // reflected in the interface and instead the Klass hierarchy |
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42 // is directly modeled as the subclasses of ciKlass. |
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43 class ciObject : public ResourceObj { |
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44 CI_PACKAGE_ACCESS |
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45 friend class ciEnv; |
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46 |
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47 private: |
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48 // A JNI handle referring to an oop in the VM. This |
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49 // handle may, in a small set of cases, correctly be NULL. |
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50 jobject _handle; |
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51 ciKlass* _klass; |
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52 uint _ident; |
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53 |
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54 enum { FLAG_BITS = 1}; |
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55 enum { |
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56 PERM_FLAG = 1 |
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57 }; |
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58 protected: |
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59 ciObject(); |
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60 ciObject(oop o); |
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61 ciObject(Handle h); |
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62 ciObject(ciKlass* klass); |
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63 |
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64 jobject handle() const { return _handle; } |
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65 // Get the VM oop that this object holds. |
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66 oop get_oop() const { |
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67 assert(_handle != NULL, "null oop"); |
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68 return JNIHandles::resolve_non_null(_handle); |
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69 } |
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70 |
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71 void set_perm() { |
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72 _ident |= PERM_FLAG; |
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73 } |
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74 |
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75 // Virtual behavior of the print() method. |
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76 virtual void print_impl(outputStream* st) {} |
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77 |
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78 virtual const char* type_string() { return "ciObject"; } |
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79 |
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80 void set_ident(uint id); |
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81 public: |
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82 // The klass of this ciObject. |
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83 ciKlass* klass(); |
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84 |
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85 // A number unique to this object. |
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86 uint ident(); |
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87 |
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88 // Are two ciObjects equal? |
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89 bool equals(ciObject* obj); |
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90 |
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91 // A hash value for the convenience of compilers. |
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92 int hash(); |
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93 |
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94 // Tells if this oop has an encoding. (I.e., is it null or perm?) |
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95 // If it does not have an encoding, the compiler is responsible for |
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96 // making other arrangements for dealing with the oop. |
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97 // See ciEnv::make_perm_array |
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98 bool has_encoding(); |
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99 |
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100 // Is this object guaranteed to be in the permanent part of the heap? |
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101 // If so, CollectedHeap::can_elide_permanent_oop_store_barriers is relevant. |
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102 // If the answer is false, no guarantees are made. |
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103 bool is_perm() { return (_ident & PERM_FLAG) != 0; } |
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104 |
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105 // The address which the compiler should embed into the |
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106 // generated code to represent this oop. This address |
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107 // is not the true address of the oop -- it will get patched |
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108 // during nmethod creation. |
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109 // |
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110 // Usage note: no address arithmetic allowed. Oop must |
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111 // be registered with the oopRecorder. |
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112 jobject encoding(); |
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113 |
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114 // What kind of ciObject is this? |
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115 virtual bool is_null_object() const { return false; } |
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116 virtual bool is_instance() { return false; } |
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117 virtual bool is_method() { return false; } |
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118 virtual bool is_method_data() { return false; } |
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119 virtual bool is_array() { return false; } |
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120 virtual bool is_obj_array() { return false; } |
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121 virtual bool is_type_array() { return false; } |
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122 virtual bool is_symbol() { return false; } |
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123 virtual bool is_type() { return false; } |
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124 virtual bool is_return_address() { return false; } |
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125 virtual bool is_klass() { return false; } |
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126 virtual bool is_instance_klass() { return false; } |
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127 virtual bool is_method_klass() { return false; } |
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128 virtual bool is_array_klass() { return false; } |
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129 virtual bool is_obj_array_klass() { return false; } |
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130 virtual bool is_type_array_klass() { return false; } |
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131 virtual bool is_symbol_klass() { return false; } |
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132 virtual bool is_klass_klass() { return false; } |
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133 virtual bool is_instance_klass_klass() { return false; } |
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134 virtual bool is_array_klass_klass() { return false; } |
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135 virtual bool is_obj_array_klass_klass() { return false; } |
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136 virtual bool is_type_array_klass_klass() { return false; } |
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137 |
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138 // Is this a type or value which has no associated class? |
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139 // It is true of primitive types and null objects. |
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140 virtual bool is_classless() const { return false; } |
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141 |
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142 // Is this ciObject a Java Language Object? That is, |
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143 // is the ciObject an instance or an array |
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144 virtual bool is_java_object() { return false; } |
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145 |
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146 // Does this ciObject represent a Java Language class? |
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147 // That is, is the ciObject an instanceKlass or arrayKlass? |
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148 virtual bool is_java_klass() { return false; } |
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149 |
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150 // Is this ciObject the ciInstanceKlass representing |
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151 // java.lang.Object()? |
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152 virtual bool is_java_lang_Object() { return false; } |
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153 |
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154 // Does this ciObject refer to a real oop in the VM? |
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155 // |
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156 // Note: some ciObjects refer to oops which have yet to be |
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157 // created. We refer to these as "unloaded". Specifically, |
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158 // there are unloaded ciMethods, ciObjArrayKlasses, and |
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159 // ciInstanceKlasses. By convention the ciNullObject is |
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160 // considered loaded, and primitive types are considered loaded. |
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161 bool is_loaded() const { |
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162 return handle() != NULL || is_classless(); |
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163 } |
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164 |
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165 // Subclass casting with assertions. |
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166 ciNullObject* as_null_object() { |
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167 assert(is_null_object(), "bad cast"); |
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168 return (ciNullObject*)this; |
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169 } |
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170 ciInstance* as_instance() { |
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171 assert(is_instance(), "bad cast"); |
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172 return (ciInstance*)this; |
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173 } |
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174 ciMethod* as_method() { |
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175 assert(is_method(), "bad cast"); |
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176 return (ciMethod*)this; |
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177 } |
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178 ciMethodData* as_method_data() { |
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179 assert(is_method_data(), "bad cast"); |
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180 return (ciMethodData*)this; |
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181 } |
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182 ciArray* as_array() { |
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183 assert(is_array(), "bad cast"); |
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184 return (ciArray*)this; |
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185 } |
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186 ciObjArray* as_obj_array() { |
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187 assert(is_obj_array(), "bad cast"); |
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188 return (ciObjArray*)this; |
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189 } |
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190 ciTypeArray* as_type_array() { |
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191 assert(is_type_array(), "bad cast"); |
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192 return (ciTypeArray*)this; |
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193 } |
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194 ciSymbol* as_symbol() { |
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195 assert(is_symbol(), "bad cast"); |
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196 return (ciSymbol*)this; |
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197 } |
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198 ciType* as_type() { |
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199 assert(is_type(), "bad cast"); |
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200 return (ciType*)this; |
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201 } |
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202 ciReturnAddress* as_return_address() { |
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203 assert(is_return_address(), "bad cast"); |
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204 return (ciReturnAddress*)this; |
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205 } |
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206 ciKlass* as_klass() { |
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207 assert(is_klass(), "bad cast"); |
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208 return (ciKlass*)this; |
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209 } |
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210 ciInstanceKlass* as_instance_klass() { |
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211 assert(is_instance_klass(), "bad cast"); |
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212 return (ciInstanceKlass*)this; |
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213 } |
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214 ciMethodKlass* as_method_klass() { |
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215 assert(is_method_klass(), "bad cast"); |
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216 return (ciMethodKlass*)this; |
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217 } |
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218 ciArrayKlass* as_array_klass() { |
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219 assert(is_array_klass(), "bad cast"); |
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220 return (ciArrayKlass*)this; |
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221 } |
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222 ciObjArrayKlass* as_obj_array_klass() { |
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223 assert(is_obj_array_klass(), "bad cast"); |
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224 return (ciObjArrayKlass*)this; |
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225 } |
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226 ciTypeArrayKlass* as_type_array_klass() { |
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227 assert(is_type_array_klass(), "bad cast"); |
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228 return (ciTypeArrayKlass*)this; |
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229 } |
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230 ciSymbolKlass* as_symbol_klass() { |
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231 assert(is_symbol_klass(), "bad cast"); |
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232 return (ciSymbolKlass*)this; |
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233 } |
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234 ciKlassKlass* as_klass_klass() { |
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235 assert(is_klass_klass(), "bad cast"); |
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236 return (ciKlassKlass*)this; |
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237 } |
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238 ciInstanceKlassKlass* as_instance_klass_klass() { |
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239 assert(is_instance_klass_klass(), "bad cast"); |
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240 return (ciInstanceKlassKlass*)this; |
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241 } |
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242 ciArrayKlassKlass* as_array_klass_klass() { |
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243 assert(is_array_klass_klass(), "bad cast"); |
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244 return (ciArrayKlassKlass*)this; |
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245 } |
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246 ciObjArrayKlassKlass* as_obj_array_klass_klass() { |
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247 assert(is_obj_array_klass_klass(), "bad cast"); |
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248 return (ciObjArrayKlassKlass*)this; |
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249 } |
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250 ciTypeArrayKlassKlass* as_type_array_klass_klass() { |
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251 assert(is_type_array_klass_klass(), "bad cast"); |
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252 return (ciTypeArrayKlassKlass*)this; |
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253 } |
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254 |
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255 // Print debugging output about this ciObject. |
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256 void print(outputStream* st = tty); |
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257 |
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258 // Print debugging output about the oop this ciObject represents. |
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259 void print_oop(outputStream* st = tty); |
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260 }; |