30 // BytecodeStream s(method); |
30 // BytecodeStream s(method); |
31 // Bytecodes::Code c; |
31 // Bytecodes::Code c; |
32 // while ((c = s.next()) >= 0) { |
32 // while ((c = s.next()) >= 0) { |
33 // ... |
33 // ... |
34 // } |
34 // } |
35 // |
35 |
36 // A RawBytecodeStream is a simple version of BytecodeStream. |
36 // A RawBytecodeStream is a simple version of BytecodeStream. |
37 // It is used ONLY when we know the bytecodes haven't been rewritten |
37 // It is used ONLY when we know the bytecodes haven't been rewritten |
38 // yet, such as in the rewriter or the verifier. Currently only the |
38 // yet, such as in the rewriter or the verifier. |
39 // verifier uses this class. |
39 |
40 |
40 // Here is the common base class for both RawBytecodeStream and BytecodeStream: |
41 class RawBytecodeStream: StackObj { |
41 class BaseBytecodeStream: StackObj { |
42 protected: |
42 protected: |
43 // stream buffer |
43 // stream buffer |
44 methodHandle _method; // read from method directly |
44 methodHandle _method; // read from method directly |
45 |
45 |
46 // reading position |
46 // reading position |
47 int _bci; // bci if current bytecode |
47 int _bci; // bci if current bytecode |
48 int _next_bci; // bci of next bytecode |
48 int _next_bci; // bci of next bytecode |
49 int _end_bci; // bci after the current iteration interval |
49 int _end_bci; // bci after the current iteration interval |
50 |
50 |
51 // last bytecode read |
51 // last bytecode read |
52 Bytecodes::Code _code; |
52 Bytecodes::Code _raw_code; |
53 bool _is_wide; |
53 bool _is_wide; |
54 |
54 bool _is_raw; // false in 'cooked' BytecodeStream |
55 public: |
55 |
56 // Construction |
56 // Construction |
57 RawBytecodeStream(methodHandle method) : _method(method) { |
57 BaseBytecodeStream(methodHandle method) : _method(method) { |
58 set_interval(0, _method->code_size()); |
58 set_interval(0, _method->code_size()); |
59 } |
59 _is_raw = false; |
60 |
60 } |
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61 |
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62 public: |
61 // Iteration control |
63 // Iteration control |
62 void set_interval(int beg_bci, int end_bci) { |
64 void set_interval(int beg_bci, int end_bci) { |
63 // iterate over the interval [beg_bci, end_bci) |
65 // iterate over the interval [beg_bci, end_bci) |
64 assert(0 <= beg_bci && beg_bci <= method()->code_size(), "illegal beg_bci"); |
66 assert(0 <= beg_bci && beg_bci <= method()->code_size(), "illegal beg_bci"); |
65 assert(0 <= end_bci && end_bci <= method()->code_size(), "illegal end_bci"); |
67 assert(0 <= end_bci && end_bci <= method()->code_size(), "illegal end_bci"); |
70 } |
72 } |
71 void set_start (int beg_bci) { |
73 void set_start (int beg_bci) { |
72 set_interval(beg_bci, _method->code_size()); |
74 set_interval(beg_bci, _method->code_size()); |
73 } |
75 } |
74 |
76 |
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77 bool is_raw() const { return _is_raw; } |
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78 |
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79 // Stream attributes |
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80 methodHandle method() const { return _method; } |
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81 |
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82 int bci() const { return _bci; } |
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83 int next_bci() const { return _next_bci; } |
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84 int end_bci() const { return _end_bci; } |
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85 |
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86 Bytecodes::Code raw_code() const { return _raw_code; } |
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87 bool is_wide() const { return _is_wide; } |
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88 int instruction_size() const { return (_next_bci - _bci); } |
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89 bool is_last_bytecode() const { return _next_bci >= _end_bci; } |
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90 |
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91 address bcp() const { return method()->code_base() + _bci; } |
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92 Bytecode* bytecode() const { return Bytecode_at(bcp()); } |
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93 |
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94 // State changes |
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95 void set_next_bci(int bci) { assert(0 <= bci && bci <= method()->code_size(), "illegal bci"); _next_bci = bci; } |
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96 |
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97 // Bytecode-specific attributes |
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98 int dest() const { return bci() + bytecode()->get_offset_s2(raw_code()); } |
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99 int dest_w() const { return bci() + bytecode()->get_offset_s4(raw_code()); } |
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100 |
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101 // One-byte indices. |
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102 int get_index_u1() const { assert_raw_index_size(1); return *(jubyte*)(bcp()+1); } |
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103 |
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104 protected: |
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105 void assert_raw_index_size(int size) const NOT_DEBUG_RETURN; |
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106 void assert_raw_stream(bool want_raw) const NOT_DEBUG_RETURN; |
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107 }; |
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108 |
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109 class RawBytecodeStream: public BaseBytecodeStream { |
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110 public: |
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111 // Construction |
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112 RawBytecodeStream(methodHandle method) : BaseBytecodeStream(method) { |
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113 _is_raw = true; |
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114 } |
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115 |
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116 public: |
75 // Iteration |
117 // Iteration |
76 // Use raw_next() rather than next() for faster method reference |
118 // Use raw_next() rather than next() for faster method reference |
77 Bytecodes::Code raw_next() { |
119 Bytecodes::Code raw_next() { |
78 Bytecodes::Code code; |
120 Bytecodes::Code code; |
79 // set reading position |
121 // set reading position |
80 _bci = _next_bci; |
122 _bci = _next_bci; |
81 assert(!is_last_bytecode(), "caller should check is_last_bytecode()"); |
123 assert(!is_last_bytecode(), "caller should check is_last_bytecode()"); |
82 |
124 |
83 address bcp = RawBytecodeStream::bcp(); |
125 address bcp = this->bcp(); |
84 code = Bytecodes::code_or_bp_at(bcp); |
126 code = Bytecodes::code_or_bp_at(bcp); |
85 |
127 |
86 // set next bytecode position |
128 // set next bytecode position |
87 int l = Bytecodes::length_for(code); |
129 int l = Bytecodes::length_for(code); |
88 if (l > 0 && (_bci + l) <= _end_bci) { |
130 if (l > 0 && (_bci + l) <= _end_bci) { |
89 assert(code != Bytecodes::_wide && code != Bytecodes::_tableswitch |
131 assert(code != Bytecodes::_wide && code != Bytecodes::_tableswitch |
90 && code != Bytecodes::_lookupswitch, "can't be special bytecode"); |
132 && code != Bytecodes::_lookupswitch, "can't be special bytecode"); |
91 _is_wide = false; |
133 _is_wide = false; |
92 _next_bci += l; |
134 _next_bci += l; |
93 _code = code; |
135 _raw_code = code; |
94 return code; |
136 return code; |
95 } else if (code == Bytecodes::_wide && _bci + 1 >= _end_bci) { |
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96 return Bytecodes::_illegal; |
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97 } else { |
137 } else { |
98 return raw_next_special(code); |
138 return raw_next_special(code); |
99 } |
139 } |
100 } |
140 } |
101 Bytecodes::Code raw_next_special(Bytecodes::Code code); |
141 Bytecodes::Code raw_next_special(Bytecodes::Code code); |
102 |
142 |
103 // Stream attributes |
143 // Unsigned indices, widening, with no swapping of bytes |
104 methodHandle method() const { return _method; } |
144 int get_index() const { return (is_wide()) ? get_index_u2_raw(bcp() + 2) : get_index_u1(); } |
105 |
145 // Get an unsigned 2-byte index, with no swapping of bytes. |
106 int bci() const { return _bci; } |
146 int get_index_u2() const { assert(!is_wide(), ""); return get_index_u2_raw(bcp() + 1); } |
107 int next_bci() const { return _next_bci; } |
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108 int end_bci() const { return _end_bci; } |
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109 |
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110 Bytecodes::Code code() const { return _code; } |
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111 bool is_wide() const { return _is_wide; } |
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112 int instruction_size() const { return (_next_bci - _bci); } |
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113 bool is_last_bytecode() const { return _next_bci >= _end_bci; } |
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114 |
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115 address bcp() const { return method()->code_base() + _bci; } |
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116 address next_bcp() { return method()->code_base() + _next_bci; } |
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117 |
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118 // State changes |
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119 void set_next_bci(int bci) { assert(0 <= bci && bci <= method()->code_size(), "illegal bci"); _next_bci = bci; } |
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120 |
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121 // Bytecode-specific attributes |
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122 int dest() const { return bci() + (short)Bytes::get_Java_u2(bcp() + 1); } |
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123 int dest_w() const { return bci() + (int )Bytes::get_Java_u4(bcp() + 1); } |
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124 |
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125 // Unsigned indices, widening |
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126 int get_index() const { assert_index_size(is_wide() ? 2 : 1); |
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127 return (is_wide()) ? Bytes::get_Java_u2(bcp() + 2) : bcp()[1]; } |
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128 int get_index_big() const { assert_index_size(2); |
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129 return (int)Bytes::get_Java_u2(bcp() + 1); } |
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130 int get_index_int() const { return has_giant_index() ? get_index_giant() : get_index_big(); } |
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131 int get_index_giant() const { assert_index_size(4); return Bytes::get_native_u4(bcp() + 1); } |
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132 int has_giant_index() const { return (code() == Bytecodes::_invokedynamic); } |
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133 |
147 |
134 private: |
148 private: |
135 void assert_index_size(int required_size) const { |
149 int get_index_u2_raw(address p) const { |
136 #ifdef ASSERT |
150 assert_raw_index_size(2); assert_raw_stream(true); |
137 int isize = instruction_size() - (int)_is_wide - 1; |
151 return Bytes::get_Java_u2(p); |
138 if (isize == 2 && code() == Bytecodes::_iinc) |
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139 isize = 1; |
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140 else if (isize <= 2) |
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141 ; // no change |
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142 else if (has_giant_index()) |
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143 isize = 4; |
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144 else |
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145 isize = 2; |
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146 assert(isize = required_size, "wrong index size"); |
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147 #endif |
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148 } |
152 } |
149 }; |
153 }; |
150 |
154 |
151 // In BytecodeStream, non-java bytecodes will be translated into the |
155 // In BytecodeStream, non-java bytecodes will be translated into the |
152 // corresponding java bytecodes. |
156 // corresponding java bytecodes. |
153 |
157 |
154 class BytecodeStream: public RawBytecodeStream { |
158 class BytecodeStream: public BaseBytecodeStream { |
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159 Bytecodes::Code _code; |
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160 |
155 public: |
161 public: |
156 // Construction |
162 // Construction |
157 BytecodeStream(methodHandle method) : RawBytecodeStream(method) { } |
163 BytecodeStream(methodHandle method) : BaseBytecodeStream(method) { } |
158 |
164 |
159 // Iteration |
165 // Iteration |
160 Bytecodes::Code next() { |
166 Bytecodes::Code next() { |
161 Bytecodes::Code code; |
167 Bytecodes::Code raw_code, code; |
162 // set reading position |
168 // set reading position |
163 _bci = _next_bci; |
169 _bci = _next_bci; |
164 if (is_last_bytecode()) { |
170 if (is_last_bytecode()) { |
165 // indicate end of bytecode stream |
171 // indicate end of bytecode stream |
166 code = Bytecodes::_illegal; |
172 raw_code = code = Bytecodes::_illegal; |
167 } else { |
173 } else { |
168 // get bytecode |
174 // get bytecode |
169 address bcp = BytecodeStream::bcp(); |
175 address bcp = this->bcp(); |
170 code = Bytecodes::java_code_at(bcp); |
176 raw_code = Bytecodes::code_at(bcp); |
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177 code = Bytecodes::java_code(raw_code); |
171 // set next bytecode position |
178 // set next bytecode position |
172 // |
179 // |
173 // note that we cannot advance before having the |
180 // note that we cannot advance before having the |
174 // tty bytecode otherwise the stepping is wrong! |
181 // tty bytecode otherwise the stepping is wrong! |
175 // (carefull: length_for(...) must be used first!) |
182 // (carefull: length_for(...) must be used first!) |
179 assert(_bci < _next_bci, "length must be > 0"); |
186 assert(_bci < _next_bci, "length must be > 0"); |
180 // set attributes |
187 // set attributes |
181 _is_wide = false; |
188 _is_wide = false; |
182 // check for special (uncommon) cases |
189 // check for special (uncommon) cases |
183 if (code == Bytecodes::_wide) { |
190 if (code == Bytecodes::_wide) { |
184 code = (Bytecodes::Code)bcp[1]; |
191 raw_code = (Bytecodes::Code)bcp[1]; |
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192 code = raw_code; // wide BCs are always Java-normal |
185 _is_wide = true; |
193 _is_wide = true; |
186 } |
194 } |
187 assert(Bytecodes::is_java_code(code), "sanity check"); |
195 assert(Bytecodes::is_java_code(code), "sanity check"); |
188 } |
196 } |
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197 _raw_code = raw_code; |
189 _code = code; |
198 _code = code; |
190 return _code; |
199 return _code; |
191 } |
200 } |
192 |
201 |
193 bool is_active_breakpoint() const { return Bytecodes::is_active_breakpoint_at(bcp()); } |
202 bool is_active_breakpoint() const { return Bytecodes::is_active_breakpoint_at(bcp()); } |
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203 Bytecodes::Code code() const { return _code; } |
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204 |
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205 // Unsigned indices, widening |
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206 int get_index() const { return is_wide() ? bytecode()->get_index_u2(raw_code(), true) : get_index_u1(); } |
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207 // Get an unsigned 2-byte index, swapping the bytes if necessary. |
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208 int get_index_u2() const { assert_raw_stream(false); |
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209 return bytecode()->get_index_u2(raw_code(), false); } |
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210 // Get an unsigned 2-byte index in native order. |
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211 int get_index_u2_cpcache() const { assert_raw_stream(false); |
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212 return bytecode()->get_index_u2_cpcache(raw_code()); } |
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213 int get_index_u4() const { assert_raw_stream(false); |
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214 return bytecode()->get_index_u4(raw_code()); } |
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215 int has_index_u4() const { return bytecode()->get_index_u4(raw_code()); } |
194 }; |
216 }; |