1 /*
2 * Copyright (c) 1997, 2024, 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.
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23 */
24
25 #ifndef SHARE_CODE_DEBUGINFO_HPP
26 #define SHARE_CODE_DEBUGINFO_HPP
27
28 #include "code/compressedStream.hpp"
29 #include "code/location.hpp"
30 #include "code/nmethod.hpp"
31 #include "code/oopRecorder.hpp"
32 #include "runtime/javaThread.hpp"
33 #include "utilities/growableArray.hpp"
34
35 // Classes used for serializing debugging information.
36 // These abstractions are introducted to provide symmetric
37 // read and write operations.
38
39 // ScopeValue describes the value of a variable/expression in a scope
40 // - LocationValue describes a value in a given location (in frame or register)
41 // - ConstantValue describes a constant
42
43 class ConstantOopReadValue;
44 class ConstantOopWriteValue;
45 class LocationValue;
46 class ObjectValue;
47 class ObjectMergeValue;
48
49 class ScopeValue: public AnyObj {
50 public:
51 // Testers
52 virtual bool is_location() const { return false; }
53 virtual bool is_object() const { return false; }
54 virtual bool is_object_merge() const { return false; }
55 virtual bool is_auto_box() const { return false; }
56 virtual bool is_marker() const { return false; }
57 virtual bool is_constant_int() const { return false; }
58 virtual bool is_constant_double() const { return false; }
59 virtual bool is_constant_long() const { return false; }
60 virtual bool is_constant_oop() const { return false; }
61 virtual bool equals(ScopeValue* other) const { return false; }
62
63 ConstantOopReadValue* as_ConstantOopReadValue() {
64 assert(is_constant_oop(), "must be");
65 return (ConstantOopReadValue*) this;
66 }
67
68 ConstantOopWriteValue* as_ConstantOopWriteValue() {
69 assert(is_constant_oop(), "must be");
70 return (ConstantOopWriteValue*) this;
71 }
72
73 ObjectValue* as_ObjectValue() {
74 assert(is_object(), "must be");
75 return (ObjectValue*)this;
76 }
77
78 ObjectMergeValue* as_ObjectMergeValue() {
79 assert(is_object_merge(), "must be");
80 return (ObjectMergeValue*)this;
81 }
82
83 LocationValue* as_LocationValue() {
84 assert(is_location(), "must be");
85 return (LocationValue*)this;
86 }
87
88 // Serialization of debugging information
89 virtual void write_on(DebugInfoWriteStream* stream) = 0;
90 static ScopeValue* read_from(DebugInfoReadStream* stream);
91 };
92
93
94 // A Location value describes a value in a given location; i.e. the corresponding
95 // logical entity (e.g., a method temporary) lives in this location.
96
97 class LocationValue: public ScopeValue {
98 private:
99 Location _location;
100 public:
101 LocationValue(Location location) { _location = location; }
102 bool is_location() const { return true; }
103 Location location() const { return _location; }
104
105 // Serialization of debugging information
106 LocationValue(DebugInfoReadStream* stream);
107 void write_on(DebugInfoWriteStream* stream);
108
109 // Printing
110 void print_on(outputStream* st) const;
111 };
112
113 // A placeholder value that has no concrete meaning other than helping constructing
114 // other values.
115
116 class MarkerValue: public ScopeValue {
117 public:
118 bool is_marker() const { return true; }
119
120 // Serialization of debugging information
121 void write_on(DebugInfoWriteStream* stream);
122
123 // Printing
124 void print_on(outputStream* st) const;
125 };
126
127 // An ObjectValue describes an object eliminated by escape analysis.
128
129 class ObjectValue: public ScopeValue {
130 protected:
131 int _id;
132 ScopeValue* _klass;
133 GrowableArray<ScopeValue*> _field_values;
134 Handle _value;
135 bool _visited;
136 bool _is_scalar_replaced; // Whether this ObjectValue describes an object scalar replaced or just
137 // an object (possibly null) participating in an allocation merge.
138 bool _is_root; // Will be true if this object is referred to
139 // as a local/expression/monitor in the JVMs.
140 // Otherwise false, meaning it's just a candidate
141 // in an object allocation merge.
142 public:
143 ObjectValue(int id, ScopeValue* klass = nullptr, bool is_scalar_replaced = true)
144 : _id(id)
145 , _klass(klass)
146 , _field_values()
147 , _value()
148 , _visited(false)
149 , _is_scalar_replaced(is_scalar_replaced)
150 , _is_root(true) {
151 assert(klass == nullptr || klass->is_constant_oop(), "should be constant java mirror oop");
152 }
153
154 // Accessors
155 bool is_object() const { return true; }
156 int id() const { return _id; }
157 virtual ScopeValue* klass() const { return _klass; }
158 virtual GrowableArray<ScopeValue*>* field_values() { return &_field_values; }
159 virtual ScopeValue* field_at(int i) const { return _field_values.at(i); }
160 virtual int field_size() { return _field_values.length(); }
161 virtual Handle value() const { return _value; }
162 bool is_visited() const { return _visited; }
163 bool is_scalar_replaced() const { return _is_scalar_replaced; }
164 bool is_root() const { return _is_root; }
165
166 void set_id(int id) { _id = id; }
167 virtual void set_value(oop value);
168 void set_visited(bool visited) { _visited = visited; }
169 void set_is_scalar_replaced(bool scd) { _is_scalar_replaced = scd; }
170 void set_root(bool root) { _is_root = root; }
171
172 // Serialization of debugging information
173 void read_object(DebugInfoReadStream* stream);
174 void write_on(DebugInfoWriteStream* stream);
175
176 // Printing
177 void print_on(outputStream* st) const;
178 void print_fields_on(outputStream* st) const;
179 };
180
181 // An ObjectMergeValue describes objects that were inputs to a Phi in C2 and at
182 // least one of them was scalar replaced.
183 // '_selector' is an integer value that will be '-1' if during the execution of
184 // the C2 compiled code the path taken was that of the Phi input that was NOT
185 // scalar replaced. In that case '_merge_pointer' is a pointer to an already
186 // allocated object. If '_selector' is not '-1' then it should be the index of
187 // an object in '_possible_objects'. That object is an ObjectValue describing an
188 // object that was scalar replaced.
189
190 class ObjectMergeValue: public ObjectValue {
191 protected:
192 ScopeValue* _selector;
193 ScopeValue* _merge_pointer;
194 GrowableArray<ScopeValue*> _possible_objects;
195
196 // This holds the ObjectValue that should be used in place of this
197 // ObjectMergeValue. I.e., it's the ScopeValue from _possible_objects that was
198 // selected by 'select()' or is a on-the-fly created ScopeValue representing
199 // the _merge_pointer if _selector is -1.
200 //
201 // We need to keep this reference around because there will be entries in
202 // ScopeDesc that reference this ObjectMergeValue directly. After
203 // rematerialization ObjectMergeValue will be just a wrapper for the
204 // Objectvalue pointed by _selected.
205 ObjectValue* _selected;
206 public:
207 ObjectMergeValue(int id, ScopeValue* merge_pointer, ScopeValue* selector)
208 : ObjectValue(id, nullptr, false)
209 , _selector(selector)
210 , _merge_pointer(merge_pointer)
211 , _possible_objects()
212 , _selected(nullptr) {}
213
214 ObjectMergeValue(int id)
215 : ObjectValue(id, nullptr, false)
216 , _selector(nullptr)
217 , _merge_pointer(nullptr)
218 , _possible_objects()
219 , _selected(nullptr) {}
220
221 bool is_object_merge() const { return true; }
222 ScopeValue* selector() const { return _selector; }
223 ScopeValue* merge_pointer() const { return _merge_pointer; }
224 GrowableArray<ScopeValue*>* possible_objects() { return &_possible_objects; }
225 ObjectValue* select(frame& fr, RegisterMap& reg_map) ;
226
227 ScopeValue* klass() const { ShouldNotReachHere(); return nullptr; }
228 GrowableArray<ScopeValue*>* field_values() { ShouldNotReachHere(); return nullptr; }
229 ScopeValue* field_at(int i) const { ShouldNotReachHere(); return nullptr; }
230 int field_size() { ShouldNotReachHere(); return -1; }
231
232 Handle value() const;
233 void set_value(oop value) { assert(_selected != nullptr, "Should call select() first."); _selected->set_value(value); }
234
235 // Serialization of debugging information
236 void read_object(DebugInfoReadStream* stream);
237 void write_on(DebugInfoWriteStream* stream);
238 };
239
240 class AutoBoxObjectValue : public ObjectValue {
241 bool _cached;
242 public:
243 bool is_auto_box() const { return true; }
244 bool is_cached() const { return _cached; }
245 void set_cached(bool cached) { _cached = cached; }
246 AutoBoxObjectValue(int id, ScopeValue* klass) : ObjectValue(id, klass), _cached(false) { }
247 AutoBoxObjectValue(int id) : ObjectValue(id), _cached(false) { }
248 };
249
250
251 // A ConstantIntValue describes a constant int; i.e., the corresponding logical entity
252 // is either a source constant or its computation has been constant-folded.
253
254 class ConstantIntValue: public ScopeValue {
255 private:
256 jint _value;
257 public:
258 ConstantIntValue(jint value) { _value = value; }
259 jint value() const { return _value; }
260 bool is_constant_int() const { return true; }
261 bool equals(ScopeValue* other) const { return false; }
262
263 // Serialization of debugging information
264 ConstantIntValue(DebugInfoReadStream* stream);
265 void write_on(DebugInfoWriteStream* stream);
266
267 // Printing
268 void print_on(outputStream* st) const;
269 };
270
271 class ConstantLongValue: public ScopeValue {
272 private:
273 jlong _value;
274 public:
275 ConstantLongValue(jlong value) { _value = value; }
276 jlong value() const { return _value; }
277 bool is_constant_long() const { return true; }
278 bool equals(ScopeValue* other) const { return false; }
279
280 // Serialization of debugging information
281 ConstantLongValue(DebugInfoReadStream* stream);
282 void write_on(DebugInfoWriteStream* stream);
283
284 // Printing
285 void print_on(outputStream* st) const;
286 };
287
288 class ConstantDoubleValue: public ScopeValue {
289 private:
290 jdouble _value;
291 public:
292 ConstantDoubleValue(jdouble value) { _value = value; }
293 jdouble value() const { return _value; }
294 bool is_constant_double() const { return true; }
295 bool equals(ScopeValue* other) const { return false; }
296
297 // Serialization of debugging information
298 ConstantDoubleValue(DebugInfoReadStream* stream);
299 void write_on(DebugInfoWriteStream* stream);
300
301 // Printing
302 void print_on(outputStream* st) const;
303 };
304
305 // A ConstantOopWriteValue is created by the compiler to
306 // be written as debugging information.
307
308 class ConstantOopWriteValue: public ScopeValue {
309 private:
310 jobject _value;
311 public:
312 ConstantOopWriteValue(jobject value) { _value = value; }
313 jobject value() const { return _value; }
314 bool is_constant_oop() const { return true; }
315 bool equals(ScopeValue* other) const { return false; }
316
317 // Serialization of debugging information
318 void write_on(DebugInfoWriteStream* stream);
319
320 // Printing
321 void print_on(outputStream* st) const;
322 };
323
324 // A ConstantOopReadValue is created by the VM when reading
325 // debug information
326
327 class ConstantOopReadValue: public ScopeValue {
328 private:
329 Handle _value;
330 public:
331 Handle value() const { return _value; }
332 bool is_constant_oop() const { return true; }
333 bool equals(ScopeValue* other) const { return false; }
334
335 // Serialization of debugging information
336 ConstantOopReadValue(DebugInfoReadStream* stream);
337 void write_on(DebugInfoWriteStream* stream);
338
339 // Printing
340 void print_on(outputStream* st) const;
341 };
342
343 // MonitorValue describes the pair used for monitor_enter and monitor_exit.
344
345 class MonitorValue: public ResourceObj {
346 private:
347 ScopeValue* _owner;
348 Location _basic_lock;
349 bool _eliminated;
350 public:
351 // Constructor
352 MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated = false);
353
354 // Accessors
355 ScopeValue* owner() const { return _owner; }
356 Location basic_lock() const { return _basic_lock; }
357 bool eliminated() const { return _eliminated; }
358
359 // Serialization of debugging information
360 MonitorValue(DebugInfoReadStream* stream);
361 void write_on(DebugInfoWriteStream* stream);
362
363 // Printing
364 void print_on(outputStream* st) const;
365 };
366
367 // DebugInfoReadStream specializes CompressedReadStream for reading
368 // debugging information. Used by ScopeDesc.
369
370 class DebugInfoReadStream : public CompressedReadStream {
371 private:
372 const nmethod* _code;
373 const nmethod* code() const { return _code; }
374 GrowableArray<ScopeValue*>* _obj_pool;
375 public:
376 DebugInfoReadStream(const nmethod* code, int offset, GrowableArray<ScopeValue*>* obj_pool = nullptr) :
377 CompressedReadStream(code->scopes_data_begin(), offset) {
378 _code = code;
379 _obj_pool = obj_pool;
380
381 } ;
382
383 oop read_oop();
384 Method* read_method() {
385 Method* o = (Method*)(code()->metadata_at(read_int()));
386 // is_metadata() is a faster check than is_metaspace_object()
387 assert(o == nullptr || o->is_metadata(), "meta data only");
388 return o;
389 }
390 ScopeValue* read_object_value(bool is_auto_box);
391 ScopeValue* read_object_merge_value();
392 ScopeValue* get_cached_object();
393 // BCI encoding is mostly unsigned, but -1 is a distinguished value
394 int read_bci() { return read_int() + InvocationEntryBci; }
395 };
396
397 // DebugInfoWriteStream specializes CompressedWriteStream for
398 // writing debugging information. Used by ScopeDescRecorder.
399
400 class DebugInfoWriteStream : public CompressedWriteStream {
401 private:
402 DebugInformationRecorder* _recorder;
403 DebugInformationRecorder* recorder() const { return _recorder; }
404 public:
405 DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size);
406 void write_handle(jobject h);
407 void write_bci(int bci) { write_int(bci - InvocationEntryBci); }
408
409 void write_metadata(Metadata* m);
410 };
411
412 #endif // SHARE_CODE_DEBUGINFO_HPP