Wed, 03 Jul 2013 11:50:29 -0700
Merge
1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #ifndef SHARE_VM_INTERPRETER_BYTECODESTREAM_HPP
26 #define SHARE_VM_INTERPRETER_BYTECODESTREAM_HPP
28 #include "interpreter/bytecode.hpp"
29 #include "memory/allocation.hpp"
30 #include "oops/method.hpp"
31 #include "runtime/handles.inline.hpp"
32 #ifdef TARGET_ARCH_x86
33 # include "bytes_x86.hpp"
34 #endif
35 #ifdef TARGET_ARCH_sparc
36 # include "bytes_sparc.hpp"
37 #endif
38 #ifdef TARGET_ARCH_zero
39 # include "bytes_zero.hpp"
40 #endif
41 #ifdef TARGET_ARCH_arm
42 # include "bytes_arm.hpp"
43 #endif
44 #ifdef TARGET_ARCH_ppc
45 # include "bytes_ppc.hpp"
46 #endif
48 // A BytecodeStream is used for fast iteration over the bytecodes
49 // of a Method*.
50 //
51 // Usage:
52 //
53 // BytecodeStream s(method);
54 // Bytecodes::Code c;
55 // while ((c = s.next()) >= 0) {
56 // ...
57 // }
59 // A RawBytecodeStream is a simple version of BytecodeStream.
60 // It is used ONLY when we know the bytecodes haven't been rewritten
61 // yet, such as in the rewriter or the verifier.
63 // Here is the common base class for both RawBytecodeStream and BytecodeStream:
64 class BaseBytecodeStream: StackObj {
65 protected:
66 // stream buffer
67 methodHandle _method; // read from method directly
69 // reading position
70 int _bci; // bci if current bytecode
71 int _next_bci; // bci of next bytecode
72 int _end_bci; // bci after the current iteration interval
74 // last bytecode read
75 Bytecodes::Code _raw_code;
76 bool _is_wide;
77 bool _is_raw; // false in 'cooked' BytecodeStream
79 // Construction
80 BaseBytecodeStream(methodHandle method) : _method(method) {
81 set_interval(0, _method->code_size());
82 _is_raw = false;
83 }
85 public:
86 // Iteration control
87 void set_interval(int beg_bci, int end_bci) {
88 // iterate over the interval [beg_bci, end_bci)
89 assert(0 <= beg_bci && beg_bci <= method()->code_size(), "illegal beg_bci");
90 assert(0 <= end_bci && end_bci <= method()->code_size(), "illegal end_bci");
91 // setup of iteration pointers
92 _bci = beg_bci;
93 _next_bci = beg_bci;
94 _end_bci = end_bci;
95 }
96 void set_start (int beg_bci) {
97 set_interval(beg_bci, _method->code_size());
98 }
100 bool is_raw() const { return _is_raw; }
102 // Stream attributes
103 methodHandle method() const { return _method; }
105 int bci() const { return _bci; }
106 int next_bci() const { return _next_bci; }
107 int end_bci() const { return _end_bci; }
109 Bytecodes::Code raw_code() const { return _raw_code; }
110 bool is_wide() const { return _is_wide; }
111 int instruction_size() const { return (_next_bci - _bci); }
112 bool is_last_bytecode() const { return _next_bci >= _end_bci; }
114 address bcp() const { return method()->code_base() + _bci; }
115 Bytecode bytecode() const { return Bytecode(_method(), bcp()); }
117 // State changes
118 void set_next_bci(int bci) { assert(0 <= bci && bci <= method()->code_size(), "illegal bci"); _next_bci = bci; }
120 // Bytecode-specific attributes
121 int dest() const { return bci() + bytecode().get_offset_s2(raw_code()); }
122 int dest_w() const { return bci() + bytecode().get_offset_s4(raw_code()); }
124 // One-byte indices.
125 int get_index_u1() const { assert_raw_index_size(1); return *(jubyte*)(bcp()+1); }
127 protected:
128 void assert_raw_index_size(int size) const NOT_DEBUG_RETURN;
129 void assert_raw_stream(bool want_raw) const NOT_DEBUG_RETURN;
130 };
132 class RawBytecodeStream: public BaseBytecodeStream {
133 public:
134 // Construction
135 RawBytecodeStream(methodHandle method) : BaseBytecodeStream(method) {
136 _is_raw = true;
137 }
139 public:
140 // Iteration
141 // Use raw_next() rather than next() for faster method reference
142 Bytecodes::Code raw_next() {
143 Bytecodes::Code code;
144 // set reading position
145 _bci = _next_bci;
146 assert(!is_last_bytecode(), "caller should check is_last_bytecode()");
148 address bcp = this->bcp();
149 code = Bytecodes::code_or_bp_at(bcp);
151 // set next bytecode position
152 int l = Bytecodes::length_for(code);
153 if (l > 0 && (_bci + l) <= _end_bci) {
154 assert(code != Bytecodes::_wide && code != Bytecodes::_tableswitch
155 && code != Bytecodes::_lookupswitch, "can't be special bytecode");
156 _is_wide = false;
157 _next_bci += l;
158 _raw_code = code;
159 return code;
160 } else {
161 return raw_next_special(code);
162 }
163 }
164 Bytecodes::Code raw_next_special(Bytecodes::Code code);
166 // Unsigned indices, widening, with no swapping of bytes
167 int get_index() const { return (is_wide()) ? get_index_u2_raw(bcp() + 2) : get_index_u1(); }
168 // Get an unsigned 2-byte index, with no swapping of bytes.
169 int get_index_u2() const { assert(!is_wide(), ""); return get_index_u2_raw(bcp() + 1); }
171 private:
172 int get_index_u2_raw(address p) const {
173 assert_raw_index_size(2); assert_raw_stream(true);
174 return Bytes::get_Java_u2(p);
175 }
176 };
178 // In BytecodeStream, non-java bytecodes will be translated into the
179 // corresponding java bytecodes.
181 class BytecodeStream: public BaseBytecodeStream {
182 Bytecodes::Code _code;
184 public:
185 // Construction
186 BytecodeStream(methodHandle method) : BaseBytecodeStream(method) { }
188 // Iteration
189 Bytecodes::Code next() {
190 Bytecodes::Code raw_code, code;
191 // set reading position
192 _bci = _next_bci;
193 if (is_last_bytecode()) {
194 // indicate end of bytecode stream
195 raw_code = code = Bytecodes::_illegal;
196 } else {
197 // get bytecode
198 address bcp = this->bcp();
199 raw_code = Bytecodes::code_at(_method(), bcp);
200 code = Bytecodes::java_code(raw_code);
201 // set next bytecode position
202 //
203 // note that we cannot advance before having the
204 // tty bytecode otherwise the stepping is wrong!
205 // (carefull: length_for(...) must be used first!)
206 int l = Bytecodes::length_for(code);
207 if (l == 0) l = Bytecodes::length_at(_method(), bcp);
208 _next_bci += l;
209 assert(_bci < _next_bci, "length must be > 0");
210 // set attributes
211 _is_wide = false;
212 // check for special (uncommon) cases
213 if (code == Bytecodes::_wide) {
214 raw_code = (Bytecodes::Code)bcp[1];
215 code = raw_code; // wide BCs are always Java-normal
216 _is_wide = true;
217 }
218 assert(Bytecodes::is_java_code(code), "sanity check");
219 }
220 _raw_code = raw_code;
221 _code = code;
222 return _code;
223 }
225 bool is_active_breakpoint() const { return Bytecodes::is_active_breakpoint_at(bcp()); }
226 Bytecodes::Code code() const { return _code; }
228 // Unsigned indices, widening
229 int get_index() const { return is_wide() ? bytecode().get_index_u2(raw_code(), true) : get_index_u1(); }
230 // Get an unsigned 2-byte index, swapping the bytes if necessary.
231 int get_index_u2() const { assert_raw_stream(false);
232 return bytecode().get_index_u2(raw_code(), false); }
233 // Get an unsigned 2-byte index in native order.
234 int get_index_u2_cpcache() const { assert_raw_stream(false);
235 return bytecode().get_index_u2_cpcache(raw_code()); }
236 int get_index_u4() const { assert_raw_stream(false);
237 return bytecode().get_index_u4(raw_code()); }
238 bool has_index_u4() const { return bytecode().has_index_u4(raw_code()); }
239 };
241 #endif // SHARE_VM_INTERPRETER_BYTECODESTREAM_HPP