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1 /* |
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2 * Copyright 2003-2006 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 class StackMapReader; |
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26 |
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27 // StackMapTable class is the StackMap table used by type checker |
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28 class StackMapTable : public StackObj { |
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29 private: |
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30 // Logically, the _frame_count (as well as many fields in the StackFrame) |
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31 // should be a u2, but if we defined the variable as that type it will |
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32 // be difficult to detect/recover from overflow or underflow conditions. |
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33 // Widening the type and making it signed will help detect these. |
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34 int32_t _code_length; |
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35 int32_t _frame_count; // Stackmap frame count |
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36 StackMapFrame** _frame_array; |
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37 |
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38 public: |
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39 StackMapTable(StackMapReader* reader, StackMapFrame* init_frame, |
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40 u2 max_locals, u2 max_stack, |
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41 char* code_data, int code_len, TRAPS); |
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42 |
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43 inline int32_t get_frame_count() const { return _frame_count; } |
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44 inline int get_offset(int index) const { |
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45 return _frame_array[index]->offset(); |
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46 } |
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47 |
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48 // Match and/or update current_frame to the frame in stackmap table with |
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49 // specified offset. Return true if the two frames match. |
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50 bool match_stackmap( |
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51 StackMapFrame* current_frame, int32_t offset, |
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52 bool match, bool update, TRAPS) const; |
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53 // Match and/or update current_frame to the frame in stackmap table with |
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54 // specified offset and frame index. Return true if the two frames match. |
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55 bool match_stackmap( |
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56 StackMapFrame* current_frame, int32_t offset, int32_t frame_index, |
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57 bool match, bool update, TRAPS) const; |
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58 |
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59 // Check jump instructions. Make sure there are no uninitialized |
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60 // instances on backward branch. |
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61 void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const; |
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62 |
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63 // The following methods are only used inside this class. |
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64 |
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65 // Returns the frame array index where the frame with offset is stored. |
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66 int get_index_from_offset(int32_t offset) const; |
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67 |
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68 // Make sure that there's no uninitialized object exist on backward branch. |
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69 void check_new_object( |
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70 const StackMapFrame* frame, int32_t target, TRAPS) const; |
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71 |
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72 // Debugging |
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73 void print() const PRODUCT_RETURN; |
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74 }; |
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75 |
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76 class StackMapStream : StackObj { |
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77 private: |
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78 typeArrayHandle _data; |
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79 int _index; |
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80 public: |
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81 StackMapStream(typeArrayHandle ah) |
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82 : _data(ah), _index(0) { |
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83 } |
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84 u1 get_u1(TRAPS) { |
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85 if (_data == NULL || _index >= _data->length()) { |
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86 stackmap_format_error("access beyond the end of attribute", CHECK_0); |
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87 } |
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88 return _data->byte_at(_index++); |
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89 } |
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90 u2 get_u2(TRAPS) { |
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91 if (_data == NULL || _index >= _data->length() - 1) { |
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92 stackmap_format_error("access beyond the end of attribute", CHECK_0); |
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93 } |
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94 u2 res = Bytes::get_Java_u2((u1*)_data->byte_at_addr(_index)); |
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95 _index += 2; |
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96 return res; |
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97 } |
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98 bool at_end() { |
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99 return (_data == NULL) || (_index == _data->length()); |
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100 } |
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101 static void stackmap_format_error(const char* msg, TRAPS); |
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102 }; |
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103 |
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104 class StackMapReader : StackObj { |
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105 private: |
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106 // information about the class and method |
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107 constantPoolHandle _cp; |
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108 ClassVerifier* _verifier; |
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109 StackMapStream* _stream; |
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110 char* _code_data; |
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111 int32_t _code_length; |
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112 |
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113 // information get from the attribute |
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114 int32_t _frame_count; // frame count |
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115 |
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116 int32_t chop(VerificationType* locals, int32_t length, int32_t chops); |
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117 VerificationType parse_verification_type(u1* flags, TRAPS); |
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118 void check_verification_type_array_size( |
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119 int32_t size, int32_t max_size, TRAPS) { |
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120 if (size < 0 || size > max_size) { |
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121 // Since this error could be caused someone rewriting the method |
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122 // but not knowing to update the stackmap data, we call the the |
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123 // verifier's error method, which may not throw an exception and |
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124 // failover to the old verifier instead. |
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125 _verifier->class_format_error( |
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126 "StackMapTable format error: bad type array size"); |
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127 } |
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128 } |
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129 |
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130 enum { |
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131 SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247, |
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132 SAME_EXTENDED = 251, |
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133 FULL = 255 |
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134 }; |
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135 |
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136 public: |
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137 // Constructor |
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138 StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data, |
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139 int32_t code_len, TRAPS) : |
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140 _verifier(v), _stream(stream), |
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141 _code_data(code_data), _code_length(code_len) { |
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142 methodHandle m = v->method(); |
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143 if (m->has_stackmap_table()) { |
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144 _cp = constantPoolHandle(THREAD, m->constants()); |
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145 _frame_count = _stream->get_u2(CHECK); |
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146 } else { |
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147 // There's no stackmap table present. Frame count and size are 0. |
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148 _frame_count = 0; |
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149 } |
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150 } |
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151 |
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152 inline int32_t get_frame_count() const { return _frame_count; } |
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153 StackMapFrame* next(StackMapFrame* pre_frame, bool first, |
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154 u2 max_locals, u2 max_stack, TRAPS); |
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155 |
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156 void check_end(TRAPS) { |
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157 if (!_stream->at_end()) { |
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158 StackMapStream::stackmap_format_error("wrong attribute size", CHECK); |
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159 } |
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160 } |
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161 }; |