1 /*
2 * Copyright (c) 1998, 2026, 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 *
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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.
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23 */
24
25 #ifndef SHARE_UTILITIES_EXCEPTIONS_HPP
26 #define SHARE_UTILITIES_EXCEPTIONS_HPP
27
28 #include "memory/allocation.hpp"
29 #include "oops/oopsHierarchy.hpp"
30 #include "runtime/atomic.hpp"
31 #include "utilities/ostream.hpp"
32 #include "utilities/sizes.hpp"
33
34 // This file provides the basic support for exception handling in the VM.
35 // Note: We do not use C++ exceptions to avoid compiler dependencies and
36 // unpredictable performance.
37 //
38 // Scheme: Exceptions are stored with the thread. There is never more
39 // than one pending exception per thread. All functions that can throw
40 // an exception carry a THREAD argument (usually the last argument and
41 // declared with the TRAPS macro). Throwing an exception means setting
42 // a pending exception in the thread. Upon return from a function that
43 // can throw an exception, we must check if an exception is pending.
44 // The CHECK macros do this in a convenient way. Carrying around the
45 // thread provides also convenient access to it (e.g. for Handle
46 // creation, w/o the need for recomputation).
47
48
49
50 // Forward declarations to be independent of the include structure.
51
52 class JavaThread;
53 class Handle;
54 class Symbol;
55 class JavaCallArguments;
56 class methodHandle;
57
58 // The ThreadShadow class is a helper class to access the _pending_exception
59 // field of the Thread class w/o having access to the Thread's interface (for
60 // include hierarchy reasons).
61
62 class ThreadShadow: public CHeapObj<mtThread> {
63 friend class VMStructs;
64
65 protected:
66 oop _pending_exception; // Thread has gc actions.
67 const char* _exception_file; // file information for exception (debugging only)
68 int _exception_line; // line information for exception (debugging only)
69 friend void check_ThreadShadow(); // checks _pending_exception offset
70
71 // The following virtual exists only to force creation of a vtable.
72 // We need ThreadShadow to have a vtable, even in product builds,
73 // so that its layout will start at an offset of zero relative to Thread.
74 // Some C++ compilers are so "clever" that they put the ThreadShadow
75 // base class at offset 4 in Thread (after Thread's vtable), if they
76 // notice that Thread has a vtable but ThreadShadow does not.
77 virtual void unused_initial_virtual() { }
78
79 public:
80 oop pending_exception() const { return _pending_exception; }
81 bool has_pending_exception() const { return _pending_exception != nullptr; }
82 const char* exception_file() const { return _exception_file; }
83 int exception_line() const { return _exception_line; }
84
85 // Code generation support
86 static ByteSize pending_exception_offset() { return byte_offset_of(ThreadShadow, _pending_exception); }
87
88 // use THROW whenever possible!
89 void set_pending_exception(oop exception, const char* file, int line);
90
91 // use CLEAR_PENDING_EXCEPTION whenever possible!
92 void clear_pending_exception();
93
94 // use CLEAR_PENDING_NONASYNC_EXCEPTION to clear probable nonasync exception.
95 void clear_pending_nonasync_exception();
96
97 void set_pending_preempted_exception();
98 void clear_pending_preempted_exception();
99 void check_preempted_exception() NOT_DEBUG_RETURN;
100
101 ThreadShadow() : _pending_exception(nullptr),
102 _exception_file(nullptr), _exception_line(0) {}
103 };
104
105
106 // Exceptions is a helper class that encapsulates all operations
107 // that require access to the thread interface and which are
108 // relatively rare. The Exceptions operations should only be
109 // used directly if the macros below are insufficient.
110
111 class Exceptions {
112 // Either `exception` or `symbol` must be non-null but not both.
113 static bool special_exception(JavaThread* thread, const char* file, int line, Handle exception, Symbol* name = nullptr, const char* message = nullptr);
114
115 // Count out of memory errors that are interesting in error diagnosis
116 static Atomic<int> _out_of_memory_error_java_heap_errors;
117 static Atomic<int> _out_of_memory_error_metaspace_errors;
118 static Atomic<int> _out_of_memory_error_class_metaspace_errors;
119
120 // Count linkage errors
121 static Atomic<int> _linkage_errors;
122
123 // Count stack overflow errors.
124 static Atomic<int> _stack_overflow_errors;
125
126 public:
127 // this enum is defined to indicate whether it is safe to
128 // ignore the encoding scheme of the original message string.
129 typedef enum {
130 safe_to_utf8 = 0,
131 unsafe_to_utf8 = 1
132 } ExceptionMsgToUtf8Mode;
133 // Throw exceptions: w/o message, w/ message & with formatted message.
134 static void _throw_oop(JavaThread* thread, const char* file, int line, oop exception);
135 static void _throw(JavaThread* thread, const char* file, int line, Handle exception, const char* msg = nullptr);
136
137 static void _throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message);
138 static void _throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message,
139 Handle loader);
140
141 static void _throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause);
142 static void _throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
143 Handle h_loader);
144
145 static void _throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause);
146 static void _throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause,
147 Handle h_loader);
148
149 static void _throw_args(JavaThread* thread, const char* file, int line,
150 Symbol* name, Symbol* signature,
151 JavaCallArguments* args);
152
153 // There is no THROW... macro for this method. Caller should remember
154 // to do a return after calling it.
155 static void fthrow(JavaThread* thread, const char* file, int line, Symbol* name,
156 const char* format, ...) ATTRIBUTE_PRINTF(5, 6);
157
158 // Create and initialize a new exception
159 static Handle new_exception(JavaThread* thread, Symbol* name,
160 Symbol* signature, JavaCallArguments* args,
161 Handle loader);
162
163 static Handle new_exception(JavaThread* thread, Symbol* name,
164 Symbol* signature, JavaCallArguments* args,
165 Handle cause,
166 Handle loader);
167
168 static Handle new_exception(JavaThread* thread, Symbol* name,
169 Handle cause,
170 Handle loader,
171 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
172
173 static Handle new_exception(JavaThread* thread, Symbol* name,
174 const char* message, Handle cause,
175 Handle loader,
176 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
177
178 static Handle new_exception(JavaThread* thread, Symbol* name,
179 const char* message,
180 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
181
182 static void throw_stack_overflow_exception(JavaThread* thread, const char* file, int line, const methodHandle& method);
183
184 static void wrap_dynamic_exception(bool is_indy, JavaThread* thread);
185
186 // Exception counting of interesting exceptions that may have caused a
187 // problem for the JVM, for reporting in the hs_err file.
188 static void increment_stack_overflow_errors();
189 static bool has_exception_counts();
190 static void count_out_of_memory_exceptions(Handle exception);
191 static void print_exception_counts_on_error(outputStream* st);
192
193 // for AbortVMOnException flag
194 static void debug_check_abort(Handle exception, const char* message = nullptr);
195 static void debug_check_abort_helper(Handle exception, const char* message = nullptr);
196 static void debug_check_abort(const char *value_string, const char* message = nullptr);
197
198 // for logging exceptions
199 static void log_exception(Handle exception, const char* message);
200 static void log_exception_stacktrace(Handle exception);
201 static void log_exception_stacktrace(Handle exception, methodHandle method, int bci);
202 };
203
204
205 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions.
206 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.:
207 //
208 // int this_function_may_trap(int x, float y, TRAPS)
209
210 #define THREAD __the_thread__
211 #define TRAPS JavaThread* THREAD
212
213
214 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending
215 // exceptions. In special situations it is necessary to handle pending exceptions explicitly,
216 // in these cases the PENDING_EXCEPTION helper macros should be used.
217 //
218 // Macro naming conventions: Macros that end with _ require a result value to be returned. They
219 // are for functions with non-void result type. The result value is usually ignored because of
220 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for
221 // _(0) since this is a frequent case. Example:
222 //
223 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0);
224 //
225 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a
226 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state-
227 // ments! Also make sure it is not used on a function call that is part of a return statement!
228
229 #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception())
230 #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception())
231 #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception())
232
233 #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (void)(0
234 #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (void)(0
235 #define CHECK_0 CHECK_(0)
236 #define CHECK_NH CHECK_(Handle())
237 #define CHECK_NULL CHECK_(nullptr)
238 #define CHECK_false CHECK_(false)
239 #define CHECK_JNI_ERR CHECK_(JNI_ERR)
240 #define CHECK_PREEMPTABLE THREAD); if (HAS_PENDING_EXCEPTION) { THREAD->check_preempted_exception(); return; } (void)(0
241 #define CHECK_PREEMPTABLE_false THREAD); if (HAS_PENDING_EXCEPTION) { THREAD->check_preempted_exception(); return false; } (void)(0
242
243 // CAUTION: These macros clears all exceptions including async exceptions, use it with caution.
244 #define CHECK_AND_CLEAR THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return; } (void)(0
245 #define CHECK_AND_CLEAR_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return result; } (void)(0
246 #define CHECK_AND_CLEAR_0 CHECK_AND_CLEAR_(0)
247 #define CHECK_AND_CLEAR_NH CHECK_AND_CLEAR_(Handle())
248 #define CHECK_AND_CLEAR_NULL CHECK_AND_CLEAR_(nullptr)
249 #define CHECK_AND_CLEAR_false CHECK_AND_CLEAR_(false)
250
251 // CAUTION: These macros clears all exceptions except probable async exceptions j.l.InternalError.
252 // So use it with caution.
253 #define CLEAR_PENDING_NONASYNC_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_nonasync_exception())
254 #define CHECK_AND_CLEAR_NONASYNC THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_NONASYNC_EXCEPTION; return; } (void)(0
255 #define CHECK_AND_CLEAR_NONASYNC_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_NONASYNC_EXCEPTION; return result; } (void)(0
256 #define CHECK_AND_CLEAR_NONASYNC_0 CHECK_AND_CLEAR_NONASYNC_(0)
257 #define CHECK_AND_CLEAR_NONASYNC_NH CHECK_AND_CLEAR_NONASYNC_(Handle())
258 #define CHECK_AND_CLEAR_NONASYNC_NULL CHECK_AND_CLEAR_NONASYNC_(nullptr)
259 #define CHECK_AND_CLEAR_NONASYNC_false CHECK_AND_CLEAR_NONASYNC_(false)
260
261 #define CLEAR_PENDING_PREEMPTED_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_preempted_exception())
262 #define CHECK_AND_CLEAR_PREEMPTED THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_PREEMPTED_EXCEPTION; return; } (void)(0
263
264
265 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be
266 // visible within the scope containing the THROW. Usually this is achieved by declaring the function
267 // with a TRAPS argument.
268
269 #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__
270
271 #define THROW_OOP(e) \
272 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; }
273
274 #define THROW_HANDLE(e) \
275 { Exceptions::_throw(THREAD_AND_LOCATION, e); return; }
276
277 #define THROW(name) \
278 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, nullptr); return; }
279
280 #define THROW_MSG(name, message) \
281 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; }
282
283 #define THROW_CAUSE(name, cause) \
284 { Exceptions::_throw_cause(THREAD_AND_LOCATION, name, cause); return; }
285
286 #define THROW_MSG_LOADER(name, message, loader) \
287 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader); return; }
288
289 #define THROW_ARG(name, signature, args) \
290 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; }
291
292 #define THROW_OOP_(e, result) \
293 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; }
294
295 #define THROW_HANDLE_(e, result) \
296 { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; }
297
298 #define THROW_(name, result) \
299 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, nullptr); return result; }
300
301 #define THROW_MSG_(name, message, result) \
302 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; }
303
304 #define THROW_MSG_LOADER_(name, message, loader, result) \
305 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader); return result; }
306
307 #define THROW_ARG_(name, signature, args, result) \
308 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; }
309
310 #define THROW_MSG_CAUSE(name, message, cause) \
311 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return; }
312
313 #define THROW_MSG_CAUSE_(name, message, cause, result) \
314 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; }
315
316
317 #define THROW_OOP_0(e) THROW_OOP_(e, 0)
318 #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0)
319 #define THROW_0(name) THROW_(name, 0)
320 #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0)
321 #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0)
322 #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0)
323 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0)
324 #define THROW_MSG_CAUSE_NULL(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, nullptr)
325
326 #define THROW_NULL(name) THROW_(name, nullptr)
327 #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, nullptr)
328
329 #define THROW_HANDLE_NULL(e) THROW_HANDLE_(e, nullptr)
330 #define THROW_ARG_NULL(name, signature, arg) THROW_ARG_(name, signature, arg, nullptr)
331
332 // The CATCH macro checks that no exception has been thrown by a function; it is used at
333 // call sites about which is statically known that the callee cannot throw an exception
334 // even though it is declared with TRAPS.
335
336 #define CATCH \
337 THREAD); if (HAS_PENDING_EXCEPTION) { \
338 oop ex = PENDING_EXCEPTION; \
339 CLEAR_PENDING_EXCEPTION; \
340 DEBUG_ONLY(ex->print();) \
341 assert(false, "CATCH"); \
342 } (void)(0
343
344 // ExceptionMark is a stack-allocated helper class for local exception handling.
345 // It is used with the EXCEPTION_MARK macro.
346
347 class ExceptionMark {
348 private:
349 JavaThread* _thread;
350 inline void check_no_pending_exception();
351
352 public:
353 ExceptionMark();
354 ExceptionMark(JavaThread* thread);
355 ~ExceptionMark();
356
357 JavaThread* thread() {
358 return _thread;
359 }
360 };
361
362 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no
363 // pending exception exists upon entering its scope and tests that no pending exception
364 // exists when leaving the scope.
365
366 // See also preserveException.hpp for PreserveExceptionMark
367 // which preserves pre-existing exceptions and does not allow new
368 // exceptions.
369
370 #define EXCEPTION_MARK ExceptionMark __em; JavaThread* THREAD = __em.thread();
371
372 #endif // SHARE_UTILITIES_EXCEPTIONS_HPP