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.
22 *
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 ScopeValue* _is_init;
134 GrowableArray<ScopeValue*> _field_values;
135 Handle _value;
136 bool _visited;
137 bool _is_scalar_replaced; // Whether this ObjectValue describes an object scalar replaced or just
138 // an object (possibly null) participating in an allocation merge.
139 bool _is_root; // Will be true if this object is referred to
140 // as a local/expression/monitor in the JVMs.
141 // Otherwise false, meaning it's just a candidate
142 // in an object allocation merge.
143 public:
144 ObjectValue(int id, ScopeValue* klass = nullptr, bool is_scalar_replaced = true, ScopeValue* is_init = nullptr)
145 : _id(id)
146 , _klass(klass)
147 , _is_init((is_init == nullptr) ? new MarkerValue() : is_init)
148 , _field_values()
149 , _value()
150 , _visited(false)
151 , _is_scalar_replaced(is_scalar_replaced)
152 , _is_root(true) {
153 assert(klass == nullptr || klass->is_constant_oop(), "should be constant java mirror oop");
154 }
155
156 // Accessors
157 bool is_object() const { return true; }
158 int id() const { return _id; }
159 virtual ScopeValue* klass() const { return _klass; }
160 virtual ScopeValue* is_init() const { return _is_init; }
161 virtual GrowableArray<ScopeValue*>* field_values() { return &_field_values; }
162 virtual ScopeValue* field_at(int i) const { return _field_values.at(i); }
163 virtual int field_size() { return _field_values.length(); }
164 virtual Handle value() const { return _value; }
165 bool is_visited() const { return _visited; }
166 bool is_scalar_replaced() const { return _is_scalar_replaced; }
167 bool is_root() const { return _is_root; }
168 bool maybe_null() const { return !_is_init->is_marker(); }
169
170 void set_id(int id) { _id = id; }
171 virtual void set_value(oop value);
172 void set_visited(bool visited) { _visited = visited; }
173 void set_is_scalar_replaced(bool scd) { _is_scalar_replaced = scd; }
174 void set_root(bool root) { _is_root = root; }
175
176 // Serialization of debugging information
177 void read_object(DebugInfoReadStream* stream);
178 void write_on(DebugInfoWriteStream* stream);
179
180 // Printing
181 void print_on(outputStream* st) const;
182 void print_fields_on(outputStream* st) const;
183 };
184
185 // An ObjectMergeValue describes objects that were inputs to a Phi in C2 and at
186 // least one of them was scalar replaced.
187 // '_selector' is an integer value that will be '-1' if during the execution of
188 // the C2 compiled code the path taken was that of the Phi input that was NOT
189 // scalar replaced. In that case '_merge_pointer' is a pointer to an already
190 // allocated object. If '_selector' is not '-1' then it should be the index of
191 // an object in '_possible_objects'. That object is an ObjectValue describing an
192 // object that was scalar replaced.
193
194 class ObjectMergeValue: public ObjectValue {
195 protected:
196 ScopeValue* _selector;
197 ScopeValue* _merge_pointer;
198 GrowableArray<ScopeValue*> _possible_objects;
199
200 // This holds the ObjectValue that should be used in place of this
201 // ObjectMergeValue. I.e., it's the ScopeValue from _possible_objects that was
202 // selected by 'select()' or is a on-the-fly created ScopeValue representing
203 // the _merge_pointer if _selector is -1.
204 //
205 // We need to keep this reference around because there will be entries in
206 // ScopeDesc that reference this ObjectMergeValue directly. After
207 // rematerialization ObjectMergeValue will be just a wrapper for the
208 // Objectvalue pointed by _selected.
209 ObjectValue* _selected;
210 public:
211 ObjectMergeValue(int id, ScopeValue* merge_pointer, ScopeValue* selector)
212 : ObjectValue(id, nullptr, false)
213 , _selector(selector)
214 , _merge_pointer(merge_pointer)
215 , _possible_objects()
216 , _selected(nullptr) {}
217
218 ObjectMergeValue(int id)
219 : ObjectValue(id, nullptr, false)
220 , _selector(nullptr)
221 , _merge_pointer(nullptr)
222 , _possible_objects()
223 , _selected(nullptr) {}
224
225 bool is_object_merge() const { return true; }
226 ScopeValue* selector() const { return _selector; }
227 ScopeValue* merge_pointer() const { return _merge_pointer; }
228 GrowableArray<ScopeValue*>* possible_objects() { return &_possible_objects; }
229 ObjectValue* select(frame& fr, RegisterMap& reg_map) ;
230
231 ScopeValue* klass() const { ShouldNotReachHere(); return nullptr; }
232 GrowableArray<ScopeValue*>* field_values() { ShouldNotReachHere(); return nullptr; }
233 ScopeValue* field_at(int i) const { ShouldNotReachHere(); return nullptr; }
234 int field_size() { ShouldNotReachHere(); return -1; }
235
236 Handle value() const;
237 void set_value(oop value) { assert(_selected != nullptr, "Should call select() first."); _selected->set_value(value); }
238
239 // Serialization of debugging information
240 void read_object(DebugInfoReadStream* stream);
241 void write_on(DebugInfoWriteStream* stream);
242 };
243
244 class AutoBoxObjectValue : public ObjectValue {
245 bool _cached;
246 public:
247 bool is_auto_box() const { return true; }
248 bool is_cached() const { return _cached; }
249 void set_cached(bool cached) { _cached = cached; }
250 AutoBoxObjectValue(int id, ScopeValue* klass) : ObjectValue(id, klass), _cached(false) { }
251 AutoBoxObjectValue(int id) : ObjectValue(id), _cached(false) { }
252 };
253
254
255 // A ConstantIntValue describes a constant int; i.e., the corresponding logical entity
256 // is either a source constant or its computation has been constant-folded.
257
258 class ConstantIntValue: public ScopeValue {
259 private:
260 jint _value;
261 public:
262 ConstantIntValue(jint value) { _value = value; }
263 jint value() const { return _value; }
264 bool is_constant_int() const { return true; }
265 bool equals(ScopeValue* other) const { return false; }
266
267 // Serialization of debugging information
268 ConstantIntValue(DebugInfoReadStream* stream);
269 void write_on(DebugInfoWriteStream* stream);
270
271 // Printing
272 void print_on(outputStream* st) const;
273 };
274
275 class ConstantLongValue: public ScopeValue {
276 private:
277 jlong _value;
278 public:
279 ConstantLongValue(jlong value) { _value = value; }
280 jlong value() const { return _value; }
281 bool is_constant_long() const { return true; }
282 bool equals(ScopeValue* other) const { return false; }
283
284 // Serialization of debugging information
285 ConstantLongValue(DebugInfoReadStream* stream);
286 void write_on(DebugInfoWriteStream* stream);
287
288 // Printing
289 void print_on(outputStream* st) const;
290 };
291
292 class ConstantDoubleValue: public ScopeValue {
293 private:
294 jdouble _value;
295 public:
296 ConstantDoubleValue(jdouble value) { _value = value; }
297 jdouble value() const { return _value; }
298 bool is_constant_double() const { return true; }
299 bool equals(ScopeValue* other) const { return false; }
300
301 // Serialization of debugging information
302 ConstantDoubleValue(DebugInfoReadStream* stream);
303 void write_on(DebugInfoWriteStream* stream);
304
305 // Printing
306 void print_on(outputStream* st) const;
307 };
308
309 // A ConstantOopWriteValue is created by the compiler to
310 // be written as debugging information.
311
312 class ConstantOopWriteValue: public ScopeValue {
313 private:
314 jobject _value;
315 public:
316 ConstantOopWriteValue(jobject value) { _value = value; }
317 jobject value() const { return _value; }
318 bool is_constant_oop() const { return true; }
319 bool equals(ScopeValue* other) const { return false; }
320
321 // Serialization of debugging information
322 void write_on(DebugInfoWriteStream* stream);
323
324 // Printing
325 void print_on(outputStream* st) const;
326 };
327
328 // A ConstantOopReadValue is created by the VM when reading
329 // debug information
330
331 class ConstantOopReadValue: public ScopeValue {
332 private:
333 Handle _value;
334 public:
335 Handle value() const { return _value; }
336 bool is_constant_oop() const { return true; }
337 bool equals(ScopeValue* other) const { return false; }
338
339 // Serialization of debugging information
340 ConstantOopReadValue(DebugInfoReadStream* stream);
341 void write_on(DebugInfoWriteStream* stream);
342
343 // Printing
344 void print_on(outputStream* st) const;
345 };
346
347 // MonitorValue describes the pair used for monitor_enter and monitor_exit.
348
349 class MonitorValue: public ResourceObj {
350 private:
351 ScopeValue* _owner;
352 Location _basic_lock;
353 bool _eliminated;
354 public:
355 // Constructor
356 MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated = false);
357
358 // Accessors
359 ScopeValue* owner() const { return _owner; }
360 Location basic_lock() const { return _basic_lock; }
361 bool eliminated() const { return _eliminated; }
362
363 // Serialization of debugging information
364 MonitorValue(DebugInfoReadStream* stream);
365 void write_on(DebugInfoWriteStream* stream);
366
367 // Printing
368 void print_on(outputStream* st) const;
369 };
370
371 // DebugInfoReadStream specializes CompressedReadStream for reading
372 // debugging information. Used by ScopeDesc.
373
374 class DebugInfoReadStream : public CompressedReadStream {
375 private:
376 const nmethod* _code;
377 const nmethod* code() const { return _code; }
378 GrowableArray<ScopeValue*>* _obj_pool;
379 public:
380 DebugInfoReadStream(const nmethod* code, int offset, GrowableArray<ScopeValue*>* obj_pool = nullptr) :
381 CompressedReadStream(code->scopes_data_begin(), offset) {
382 _code = code;
383 _obj_pool = obj_pool;
384
385 } ;
386
387 oop read_oop();
388 Method* read_method() {
389 Method* o = (Method*)(code()->metadata_at(read_int()));
390 // is_metadata() is a faster check than is_metaspace_object()
391 assert(o == nullptr || o->is_metadata(), "meta data only");
392 return o;
393 }
394 ScopeValue* read_object_value(bool is_auto_box);
395 ScopeValue* read_object_merge_value();
396 ScopeValue* get_cached_object();
397 // BCI encoding is mostly unsigned, but -1 is a distinguished value
398 int read_bci() { return read_int() + InvocationEntryBci; }
399 };
400
401 // DebugInfoWriteStream specializes CompressedWriteStream for
402 // writing debugging information. Used by ScopeDescRecorder.
403
404 class DebugInfoWriteStream : public CompressedWriteStream {
405 private:
406 DebugInformationRecorder* _recorder;
407 DebugInformationRecorder* recorder() const { return _recorder; }
408 public:
409 DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size);
410 void write_handle(jobject h);
411 void write_bci(int bci) { write_int(bci - InvocationEntryBci); }
412
413 void write_metadata(Metadata* m);
414 };
415
416 #endif // SHARE_CODE_DEBUGINFO_HPP