1 /*
2 * Copyright (c) 1998, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
8 *
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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,
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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 "utilities/ostream.hpp"
31 #include "utilities/sizes.hpp"
32
33 // This file provides the basic support for exception handling in the VM.
34 // Note: We do not use C++ exceptions to avoid compiler dependencies and
35 // unpredictable performance.
36 //
37 // Scheme: Exceptions are stored with the thread. There is never more
38 // than one pending exception per thread. All functions that can throw
39 // an exception carry a THREAD argument (usually the last argument and
40 // declared with the TRAPS macro). Throwing an exception means setting
41 // a pending exception in the thread. Upon return from a function that
42 // can throw an exception, we must check if an exception is pending.
43 // The CHECK macros do this in a convenient way. Carrying around the
44 // thread provides also convenient access to it (e.g. for Handle
45 // creation, w/o the need for recomputation).
46
47
48
49 // Forward declarations to be independent of the include structure.
50
51 class JavaThread;
52 class Handle;
53 class Symbol;
54 class JavaCallArguments;
55 class methodHandle;
56
57 // The ThreadShadow class is a helper class to access the _pending_exception
58 // field of the Thread class w/o having access to the Thread's interface (for
59 // include hierarchy reasons).
60
61 class ThreadShadow: public CHeapObj<mtThread> {
62 friend class VMStructs;
63 friend class JVMCIVMStructs;
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 volatile int _out_of_memory_error_java_heap_errors;
117 static volatile int _out_of_memory_error_metaspace_errors;
118 static volatile int _out_of_memory_error_class_metaspace_errors;
119
120 // Count linkage errors
121 static volatile int _linkage_errors;
122 public:
123 // this enum is defined to indicate whether it is safe to
124 // ignore the encoding scheme of the original message string.
125 typedef enum {
126 safe_to_utf8 = 0,
127 unsafe_to_utf8 = 1
128 } ExceptionMsgToUtf8Mode;
129 // Throw exceptions: w/o message, w/ message & with formatted message.
130 static void _throw_oop(JavaThread* thread, const char* file, int line, oop exception);
131 static void _throw(JavaThread* thread, const char* file, int line, Handle exception, const char* msg = nullptr);
132
133 static void _throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message);
134 static void _throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message,
135 Handle loader);
136
137 static void _throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause);
138 static void _throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
139 Handle h_loader);
140
141 static void _throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause);
142 static void _throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause,
143 Handle h_loader);
144
145 static void _throw_args(JavaThread* thread, const char* file, int line,
146 Symbol* name, Symbol* signature,
147 JavaCallArguments* args);
148
149 // There is no THROW... macro for this method. Caller should remember
150 // to do a return after calling it.
151 static void fthrow(JavaThread* thread, const char* file, int line, Symbol* name,
152 const char* format, ...) ATTRIBUTE_PRINTF(5, 6);
153
154 // Create and initialize a new exception
155 static Handle new_exception(JavaThread* thread, Symbol* name,
156 Symbol* signature, JavaCallArguments* args,
157 Handle loader);
158
159 static Handle new_exception(JavaThread* thread, Symbol* name,
160 Symbol* signature, JavaCallArguments* args,
161 Handle cause,
162 Handle loader);
163
164 static Handle new_exception(JavaThread* thread, Symbol* name,
165 Handle cause,
166 Handle loader,
167 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
168
169 static Handle new_exception(JavaThread* thread, Symbol* name,
170 const char* message, Handle cause,
171 Handle loader,
172 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
173
174 static Handle new_exception(JavaThread* thread, Symbol* name,
175 const char* message,
176 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
177
178 static void throw_stack_overflow_exception(JavaThread* thread, const char* file, int line, const methodHandle& method);
179
180 static void wrap_dynamic_exception(bool is_indy, JavaThread* thread);
181
182 // Exception counting for error files of interesting exceptions that may have
183 // caused a problem for the jvm
184 static volatile int _stack_overflow_errors;
185
186 static bool has_exception_counts();
187 static void count_out_of_memory_exceptions(Handle exception);
188 static void print_exception_counts_on_error(outputStream* st);
189
190 // for AbortVMOnException flag
191 static void debug_check_abort(Handle exception, const char* message = nullptr);
192 static void debug_check_abort_helper(Handle exception, const char* message = nullptr);
193 static void debug_check_abort(const char *value_string, const char* message = nullptr);
194
195 // for logging exceptions
196 static void log_exception(Handle exception, const char* message);
197 };
198
199
200 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions.
201 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.:
202 //
203 // int this_function_may_trap(int x, float y, TRAPS)
204
205 #define THREAD __the_thread__
206 #define TRAPS JavaThread* THREAD
207
208
209 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending
210 // exceptions. In special situations it is necessary to handle pending exceptions explicitly,
211 // in these cases the PENDING_EXCEPTION helper macros should be used.
212 //
213 // Macro naming conventions: Macros that end with _ require a result value to be returned. They
214 // are for functions with non-void result type. The result value is usually ignored because of
215 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for
216 // _(0) since this is a frequent case. Example:
217 //
218 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0);
219 //
220 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a
221 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state-
222 // ments! Also make sure it is not used on a function call that is part of a return statement!
223
224 #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception())
225 #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception())
226 #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception())
227
228 #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (void)(0
229 #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (void)(0
230 #define CHECK_0 CHECK_(0)
231 #define CHECK_NH CHECK_(Handle())
232 #define CHECK_NULL CHECK_(nullptr)
233 #define CHECK_false CHECK_(false)
234 #define CHECK_JNI_ERR CHECK_(JNI_ERR)
235 #define CHECK_PREEMPTABLE THREAD); if (HAS_PENDING_EXCEPTION) { THREAD->check_preempted_exception(); return; } (void)(0
236 #define CHECK_PREEMPTABLE_false THREAD); if (HAS_PENDING_EXCEPTION) { THREAD->check_preempted_exception(); return false; } (void)(0
237
238 // CAUTION: These macros clears all exceptions including async exceptions, use it with caution.
239 #define CHECK_AND_CLEAR THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return; } (void)(0
240 #define CHECK_AND_CLEAR_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return result; } (void)(0
241 #define CHECK_AND_CLEAR_0 CHECK_AND_CLEAR_(0)
242 #define CHECK_AND_CLEAR_NH CHECK_AND_CLEAR_(Handle())
243 #define CHECK_AND_CLEAR_NULL CHECK_AND_CLEAR_(nullptr)
244 #define CHECK_AND_CLEAR_false CHECK_AND_CLEAR_(false)
245
246 // CAUTION: These macros clears all exceptions except probable async exceptions j.l.InternalError.
247 // So use it with caution.
248 #define CLEAR_PENDING_NONASYNC_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_nonasync_exception())
249 #define CHECK_AND_CLEAR_NONASYNC THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_NONASYNC_EXCEPTION; return; } (void)(0
250 #define CHECK_AND_CLEAR_NONASYNC_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_NONASYNC_EXCEPTION; return result; } (void)(0
251 #define CHECK_AND_CLEAR_NONASYNC_0 CHECK_AND_CLEAR_NONASYNC_(0)
252 #define CHECK_AND_CLEAR_NONASYNC_NH CHECK_AND_CLEAR_NONASYNC_(Handle())
253 #define CHECK_AND_CLEAR_NONASYNC_NULL CHECK_AND_CLEAR_NONASYNC_(nullptr)
254 #define CHECK_AND_CLEAR_NONASYNC_false CHECK_AND_CLEAR_NONASYNC_(false)
255
256 #define CLEAR_PENDING_PREEMPTED_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_preempted_exception())
257 #define CHECK_AND_CLEAR_PREEMPTED THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_PREEMPTED_EXCEPTION; return; } (void)(0
258
259
260 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be
261 // visible within the scope containing the THROW. Usually this is achieved by declaring the function
262 // with a TRAPS argument.
263
264 #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__
265
266 #define THROW_OOP(e) \
267 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; }
268
269 #define THROW_HANDLE(e) \
270 { Exceptions::_throw(THREAD_AND_LOCATION, e); return; }
271
272 #define THROW(name) \
273 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, nullptr); return; }
274
275 #define THROW_MSG(name, message) \
276 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; }
277
278 #define THROW_CAUSE(name, cause) \
279 { Exceptions::_throw_cause(THREAD_AND_LOCATION, name, cause); return; }
280
281 #define THROW_MSG_LOADER(name, message, loader) \
282 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader); return; }
283
284 #define THROW_ARG(name, signature, args) \
285 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; }
286
287 #define THROW_OOP_(e, result) \
288 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; }
289
290 #define THROW_HANDLE_(e, result) \
291 { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; }
292
293 #define THROW_(name, result) \
294 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, nullptr); return result; }
295
296 #define THROW_MSG_(name, message, result) \
297 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; }
298
299 #define THROW_MSG_LOADER_(name, message, loader, result) \
300 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader); return result; }
301
302 #define THROW_ARG_(name, signature, args, result) \
303 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; }
304
305 #define THROW_MSG_CAUSE(name, message, cause) \
306 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return; }
307
308 #define THROW_MSG_CAUSE_(name, message, cause, result) \
309 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; }
310
311
312 #define THROW_OOP_0(e) THROW_OOP_(e, 0)
313 #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0)
314 #define THROW_0(name) THROW_(name, 0)
315 #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0)
316 #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0)
317 #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0)
318 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0)
319 #define THROW_MSG_CAUSE_NULL(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, nullptr)
320
321 #define THROW_NULL(name) THROW_(name, nullptr)
322 #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, nullptr)
323
324 #define THROW_HANDLE_NULL(e) THROW_HANDLE_(e, nullptr)
325 #define THROW_ARG_NULL(name, signature, arg) THROW_ARG_(name, signature, arg, nullptr)
326
327 // The CATCH macro checks that no exception has been thrown by a function; it is used at
328 // call sites about which is statically known that the callee cannot throw an exception
329 // even though it is declared with TRAPS.
330
331 #define CATCH \
332 THREAD); if (HAS_PENDING_EXCEPTION) { \
333 oop ex = PENDING_EXCEPTION; \
334 CLEAR_PENDING_EXCEPTION; \
335 DEBUG_ONLY(ex->print();) \
336 assert(false, "CATCH"); \
337 } (void)(0
338
339 // ExceptionMark is a stack-allocated helper class for local exception handling.
340 // It is used with the EXCEPTION_MARK macro.
341
342 class ExceptionMark {
343 private:
344 JavaThread* _thread;
345 inline void check_no_pending_exception();
346
347 public:
348 ExceptionMark();
349 ExceptionMark(JavaThread* thread);
350 ~ExceptionMark();
351
352 JavaThread* thread() {
353 return _thread;
354 }
355 };
356
357 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no
358 // pending exception exists upon entering its scope and tests that no pending exception
359 // exists when leaving the scope.
360
361 // See also preserveException.hpp for PreserveExceptionMark
362 // which preserves pre-existing exceptions and does not allow new
363 // exceptions.
364
365 #define EXCEPTION_MARK ExceptionMark __em; JavaThread* THREAD = __em.thread();
366
367 #endif // SHARE_UTILITIES_EXCEPTIONS_HPP