Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/interpreter/bytecodeStream.hpp
src/share/vm/interpreter/bytecodeStream.hpp
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| 1 /* | |
| 2 * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved. | |
| 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
| 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 // A BytecodeStream is used for fast iteration over the bytecodes | |
| 26 // of a methodOop. | |
| 27 // | |
| 28 // Usage: | |
| 29 // | |
| 30 // BytecodeStream s(method); | |
| 31 // Bytecodes::Code c; | |
| 32 // while ((c = s.next()) >= 0) { | |
| 33 // ... | |
| 34 // } | |
| 35 // | |
| 36 // A RawBytecodeStream is a simple version of BytecodeStream. | |
| 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 | |
| 39 // verifier uses this class. | |
| 40 | |
| 41 class RawBytecodeStream: StackObj { | |
| 42 protected: | |
| 43 // stream buffer | |
| 44 methodHandle _method; // read from method directly | |
| 45 | |
| 46 // reading position | |
| 47 int _bci; // bci if current bytecode | |
| 48 int _next_bci; // bci of next bytecode | |
| 49 int _end_bci; // bci after the current iteration interval | |
| 50 | |
| 51 // last bytecode read | |
| 52 Bytecodes::Code _code; | |
| 53 bool _is_wide; | |
| 54 | |
| 55 public: | |
| 56 // Construction | |
| 57 RawBytecodeStream(methodHandle method) : _method(method) { | |
| 58 set_interval(0, _method->code_size()); | |
| 59 } | |
| 60 | |
| 61 // Iteration control | |
| 62 void set_interval(int beg_bci, int end_bci) { | |
| 63 // iterate over the interval [beg_bci, end_bci) | |
| 64 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"); | |
| 66 // setup of iteration pointers | |
| 67 _bci = beg_bci; | |
| 68 _next_bci = beg_bci; | |
| 69 _end_bci = end_bci; | |
| 70 } | |
| 71 void set_start (int beg_bci) { | |
| 72 set_interval(beg_bci, _method->code_size()); | |
| 73 } | |
| 74 | |
| 75 // Iteration | |
| 76 // Use raw_next() rather than next() for faster method reference | |
| 77 Bytecodes::Code raw_next() { | |
| 78 Bytecodes::Code code; | |
| 79 // set reading position | |
| 80 _bci = _next_bci; | |
| 81 assert(!is_last_bytecode(), "caller should check is_last_bytecode()"); | |
| 82 | |
| 83 address bcp = RawBytecodeStream::bcp(); | |
| 84 code = Bytecodes::code_or_bp_at(bcp); | |
| 85 | |
| 86 // set next bytecode position | |
| 87 int l = Bytecodes::length_for(code); | |
| 88 if (l > 0 && (_bci + l) <= _end_bci) { | |
| 89 assert(code != Bytecodes::_wide && code != Bytecodes::_tableswitch | |
| 90 && code != Bytecodes::_lookupswitch, "can't be special bytecode"); | |
| 91 _is_wide = false; | |
| 92 _next_bci += l; | |
| 93 _code = code; | |
| 94 return code; | |
| 95 } else if (code == Bytecodes::_wide && _bci + 1 >= _end_bci) { | |
| 96 return Bytecodes::_illegal; | |
| 97 } else { | |
| 98 return raw_next_special(code); | |
| 99 } | |
| 100 } | |
| 101 Bytecodes::Code raw_next_special(Bytecodes::Code code); | |
| 102 | |
| 103 // Stream attributes | |
| 104 methodHandle method() const { return _method; } | |
| 105 | |
| 106 int bci() const { return _bci; } | |
| 107 int next_bci() const { return _next_bci; } | |
| 108 int end_bci() const { return _end_bci; } | |
| 109 | |
| 110 Bytecodes::Code code() const { return _code; } | |
| 111 bool is_wide() const { return _is_wide; } | |
| 112 bool is_last_bytecode() const { return _next_bci >= _end_bci; } | |
| 113 | |
| 114 address bcp() const { return method()->code_base() + _bci; } | |
| 115 address next_bcp() { return method()->code_base() + _next_bci; } | |
| 116 | |
| 117 // State changes | |
| 118 void set_next_bci(int bci) { assert(0 <= bci && bci <= method()->code_size(), "illegal bci"); _next_bci = bci; } | |
| 119 | |
| 120 // Bytecode-specific attributes | |
| 121 int dest() const { return bci() + (short)Bytes::get_Java_u2(bcp() + 1); } | |
| 122 int dest_w() const { return bci() + (int )Bytes::get_Java_u4(bcp() + 1); } | |
| 123 | |
| 124 // Unsigned indices, widening | |
| 125 int get_index() const { return (is_wide()) ? Bytes::get_Java_u2(bcp() + 2) : bcp()[1]; } | |
| 126 int get_index_big() const { return (int)Bytes::get_Java_u2(bcp() + 1); } | |
| 127 }; | |
| 128 | |
| 129 // In BytecodeStream, non-java bytecodes will be translated into the | |
| 130 // corresponding java bytecodes. | |
| 131 | |
| 132 class BytecodeStream: public RawBytecodeStream { | |
| 133 public: | |
| 134 // Construction | |
| 135 BytecodeStream(methodHandle method) : RawBytecodeStream(method) { } | |
| 136 | |
| 137 // Iteration | |
| 138 Bytecodes::Code next() { | |
| 139 Bytecodes::Code code; | |
| 140 // set reading position | |
| 141 _bci = _next_bci; | |
| 142 if (is_last_bytecode()) { | |
| 143 // indicate end of bytecode stream | |
| 144 code = Bytecodes::_illegal; | |
| 145 } else { | |
| 146 // get bytecode | |
| 147 address bcp = BytecodeStream::bcp(); | |
| 148 code = Bytecodes::java_code_at(bcp); | |
| 149 // set next bytecode position | |
| 150 // | |
| 151 // note that we cannot advance before having the | |
| 152 // tty bytecode otherwise the stepping is wrong! | |
| 153 // (carefull: length_for(...) must be used first!) | |
| 154 int l = Bytecodes::length_for(code); | |
| 155 if (l == 0) l = Bytecodes::length_at(bcp); | |
| 156 _next_bci += l; | |
| 157 assert(_bci < _next_bci, "length must be > 0"); | |
| 158 // set attributes | |
| 159 _is_wide = false; | |
| 160 // check for special (uncommon) cases | |
| 161 if (code == Bytecodes::_wide) { | |
| 162 code = (Bytecodes::Code)bcp[1]; | |
| 163 _is_wide = true; | |
| 164 } | |
| 165 assert(Bytecodes::is_java_code(code), "sanity check"); | |
| 166 } | |
| 167 _code = code; | |
| 168 return _code; | |
| 169 } | |
| 170 | |
| 171 bool is_active_breakpoint() const { return Bytecodes::is_active_breakpoint_at(bcp()); } | |
| 172 }; |
