1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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,
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 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
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 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 hierachy 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 != NULL; }
 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   ThreadShadow() : _pending_exception(NULL),
 98                    _exception_file(NULL), _exception_line(0) {}
 99 };
100 
101 
102 // Exceptions is a helper class that encapsulates all operations
103 // that require access to the thread interface and which are
104 // relatively rare. The Exceptions operations should only be
105 // used directly if the macros below are insufficient.
106 
107 class Exceptions {
108   static bool special_exception(JavaThread* thread, const char* file, int line, Handle exception);
109   static bool special_exception(JavaThread* thread, const char* file, int line, Symbol* name, const char* message);
110 
111   // Count out of memory errors that are interesting in error diagnosis
112   static volatile int _out_of_memory_error_java_heap_errors;
113   static volatile int _out_of_memory_error_metaspace_errors;
114   static volatile int _out_of_memory_error_class_metaspace_errors;
115 
116   // Count linkage errors
117   static volatile int _linkage_errors;
118  public:
119   // this enum is defined to indicate whether it is safe to
120   // ignore the encoding scheme of the original message string.
121   typedef enum {
122     safe_to_utf8 = 0,
123     unsafe_to_utf8 = 1
124   } ExceptionMsgToUtf8Mode;
125   // Throw exceptions: w/o message, w/ message & with formatted message.
126   static void _throw_oop(JavaThread* thread, const char* file, int line, oop exception);
127   static void _throw(JavaThread* thread, const char* file, int line, Handle exception, const char* msg = NULL);
128 
129   static void _throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message);
130   static void _throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message,
131                          Handle loader, Handle protection_domain);
132 
133   static void _throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause);
134   static void _throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
135                                Handle h_loader, Handle h_protection_domain);
136 
137   static void _throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause);
138   static void _throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause,
139                            Handle h_loader, Handle h_protection_domain);
140 
141   static void _throw_args(JavaThread* thread, const char* file, int line,
142                           Symbol* name, Symbol* signature,
143                           JavaCallArguments* args);
144 
145   // There is no THROW... macro for this method. Caller should remember
146   // to do a return after calling it.
147   static void fthrow(JavaThread* thread, const char* file, int line, Symbol* name,
148                      const char* format, ...) ATTRIBUTE_PRINTF(5, 6);
149 
150   // Create and initialize a new exception
151   static Handle new_exception(JavaThread* thread, Symbol* name,
152                               Symbol* signature, JavaCallArguments* args,
153                               Handle loader, Handle protection_domain);
154 
155   static Handle new_exception(JavaThread* thread, Symbol* name,
156                               Symbol* signature, JavaCallArguments* args,
157                               Handle cause,
158                               Handle loader, Handle protection_domain);
159 
160   static Handle new_exception(JavaThread* thread, Symbol* name,
161                               Handle cause,
162                               Handle loader, Handle protection_domain,
163                               ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
164 
165   static Handle new_exception(JavaThread* thread, Symbol* name,
166                               const char* message, Handle cause,
167                               Handle loader, Handle protection_domain,
168                               ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
169 
170   static Handle new_exception(JavaThread* thread, Symbol* name,
171                               const char* message,
172                               ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
173 
174   static void throw_stack_overflow_exception(JavaThread* thread, const char* file, int line, const methodHandle& method);
175 
176   static void throw_unsafe_access_internal_error(JavaThread* thread, const char* file, int line, const char* message);
177 
178   static void wrap_dynamic_exception(bool is_indy, JavaThread* thread);
179 
180   // Exception counting for error files of interesting exceptions that may have
181   // caused a problem for the jvm
182   static volatile int _stack_overflow_errors;
183 
184   static bool has_exception_counts();
185   static void count_out_of_memory_exceptions(Handle exception);
186   static void print_exception_counts_on_error(outputStream* st);
187 
188   // for AbortVMOnException flag
189   static void debug_check_abort(Handle exception, const char* message = NULL);
190   static void debug_check_abort_helper(Handle exception, const char* message = NULL);
191   static void debug_check_abort(const char *value_string, const char* message = NULL);
192 
193   // for logging exceptions
194   static void log_exception(Handle exception, const char* message);
195 };
196 
197 
198 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions.
199 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.:
200 //
201 // int this_function_may_trap(int x, float y, TRAPS)
202 
203 #define THREAD __the_thread__
204 #define TRAPS  JavaThread* THREAD
205 
206 
207 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending
208 // exceptions. In special situations it is necessary to handle pending exceptions explicitly,
209 // in these cases the PENDING_EXCEPTION helper macros should be used.
210 //
211 // Macro naming conventions: Macros that end with _ require a result value to be returned. They
212 // are for functions with non-void result type. The result value is usually ignored because of
213 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for
214 // _(0) since this is a frequent case. Example:
215 //
216 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0);
217 //
218 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a
219 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state-
220 // ments! Also make sure it is not used on a function call that is part of a return statement!
221 
222 #define PENDING_EXCEPTION                        (((ThreadShadow*)THREAD)->pending_exception())
223 #define HAS_PENDING_EXCEPTION                    (((ThreadShadow*)THREAD)->has_pending_exception())
224 #define CLEAR_PENDING_EXCEPTION                  (((ThreadShadow*)THREAD)->clear_pending_exception())
225 
226 #define CHECK                                    THREAD); if (HAS_PENDING_EXCEPTION) return       ; (void)(0
227 #define CHECK_(result)                           THREAD); if (HAS_PENDING_EXCEPTION) return result; (void)(0
228 #define CHECK_0                                  CHECK_(0)
229 #define CHECK_NH                                 CHECK_(Handle())
230 #define CHECK_NULL                               CHECK_(NULL)
231 #define CHECK_false                              CHECK_(false)
232 #define CHECK_JNI_ERR                            CHECK_(JNI_ERR)
233 
234 // CAUTION: These macros clears all exceptions including async exceptions, use it with caution.
235 #define CHECK_AND_CLEAR                         THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return;        } (void)(0
236 #define CHECK_AND_CLEAR_(result)                THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return result; } (void)(0
237 #define CHECK_AND_CLEAR_0                       CHECK_AND_CLEAR_(0)
238 #define CHECK_AND_CLEAR_NH                      CHECK_AND_CLEAR_(Handle())
239 #define CHECK_AND_CLEAR_NULL                    CHECK_AND_CLEAR_(NULL)
240 #define CHECK_AND_CLEAR_false                   CHECK_AND_CLEAR_(false)
241 
242 // CAUTION: These macros clears all exceptions except probable async exceptions j.l.InternalError and j.l.ThreadDeath.
243 // So use it with caution.
244 #define CLEAR_PENDING_NONASYNC_EXCEPTION        (((ThreadShadow*)THREAD)->clear_pending_nonasync_exception())
245 #define CHECK_AND_CLEAR_NONASYNC                THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_NONASYNC_EXCEPTION; return; } (void)(0
246 #define CHECK_AND_CLEAR_NONASYNC_(result)       THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_NONASYNC_EXCEPTION; return result; } (void)(0
247 #define CHECK_AND_CLEAR_NONASYNC_0              CHECK_AND_CLEAR_NONASYNC_(0)
248 #define CHECK_AND_CLEAR_NONASYNC_NH             CHECK_AND_CLEAR_NONASYNC_(Handle())
249 #define CHECK_AND_CLEAR_NONASYNC_NULL           CHECK_AND_CLEAR_NONASYNC_(NULL)
250 #define CHECK_AND_CLEAR_NONASYNC_false          CHECK_AND_CLEAR_NONASYNC_(false)
251 
252 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be
253 // visible within the scope containing the THROW. Usually this is achieved by declaring the function
254 // with a TRAPS argument.
255 
256 #define THREAD_AND_LOCATION                      THREAD, __FILE__, __LINE__
257 #define THREAD_AND_LOCATION_DECL                 TRAPS, const char* file, int line
258 #define THREAD_AND_LOCATION_ARGS                 THREAD, file, line
259 
260 #define THROW_OOP(e)                                \
261   { Exceptions::_throw_oop(THREAD_AND_LOCATION, e);                             return;  }
262 
263 #define THROW_HANDLE(e)                                \
264   { Exceptions::_throw(THREAD_AND_LOCATION, e);                             return;  }
265 
266 #define THROW(name)                                 \
267   { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return;  }
268 
269 #define THROW_MSG(name, message)                    \
270   { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return;  }
271 
272 #define THROW_CAUSE(name, cause)   \
273   { Exceptions::_throw_cause(THREAD_AND_LOCATION, name, cause); return; }
274 
275 #define THROW_MSG_LOADER(name, message, loader, protection_domain) \
276   { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return;  }
277 
278 #define THROW_ARG(name, signature, args) \
279   { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args);   return; }
280 
281 #define THROW_OOP_(e, result)                       \
282   { Exceptions::_throw_oop(THREAD_AND_LOCATION, e);                           return result; }
283 
284 #define THROW_HANDLE_(e, result)                       \
285   { Exceptions::_throw(THREAD_AND_LOCATION, e);                           return result; }
286 
287 #define THROW_(name, result)                        \
288   { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return result; }
289 
290 #define THROW_MSG_(name, message, result)           \
291   { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; }
292 
293 #define THROW_MSG_LOADER_(name, message, loader, protection_domain, result) \
294   { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return result; }
295 
296 #define THROW_ARG_(name, signature, args, result) \
297   { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; }
298 
299 #define THROW_MSG_CAUSE(name, message, cause)   \
300   { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return; }
301 
302 #define THROW_MSG_CAUSE_(name, message, cause, result)   \
303   { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; }
304 
305 
306 #define THROW_OOP_0(e)                      THROW_OOP_(e, 0)
307 #define THROW_HANDLE_0(e)                   THROW_HANDLE_(e, 0)
308 #define THROW_0(name)                       THROW_(name, 0)
309 #define THROW_MSG_0(name, message)          THROW_MSG_(name, message, 0)
310 #define THROW_WRAPPED_0(name, oop_to_wrap)  THROW_WRAPPED_(name, oop_to_wrap, 0)
311 #define THROW_ARG_0(name, signature, arg)   THROW_ARG_(name, signature, arg, 0)
312 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0)
313 #define THROW_MSG_CAUSE_NULL(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, NULL)
314 
315 #define THROW_NULL(name)                    THROW_(name, NULL)
316 #define THROW_MSG_NULL(name, message)       THROW_MSG_(name, message, NULL)
317 
318 // The CATCH macro checks that no exception has been thrown by a function; it is used at
319 // call sites about which is statically known that the callee cannot throw an exception
320 // even though it is declared with TRAPS.
321 
322 #define CATCH                              \
323   THREAD); if (HAS_PENDING_EXCEPTION) {    \
324     oop ex = PENDING_EXCEPTION;            \
325     CLEAR_PENDING_EXCEPTION;               \
326     DEBUG_ONLY(ex->print();)               \
327     assert(false, "CATCH");                \
328   } (void)(0
329 
330 // ExceptionMark is a stack-allocated helper class for local exception handling.
331 // It is used with the EXCEPTION_MARK macro.
332 
333 class ExceptionMark {
334  private:
335   JavaThread* _thread;
336   inline void check_no_pending_exception();
337 
338  public:
339   ExceptionMark();
340   ExceptionMark(JavaThread* thread);
341   ~ExceptionMark();
342 
343   JavaThread* thread() {
344     return _thread;
345   }
346 };
347 
348 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no
349 // pending exception exists upon entering its scope and tests that no pending exception
350 // exists when leaving the scope.
351 
352 // See also preserveException.hpp for PreserveExceptionMark
353 // which preserves pre-existing exceptions and does not allow new
354 // exceptions.
355 
356 #define EXCEPTION_MARK                           ExceptionMark __em; JavaThread* THREAD = __em.thread();
357 
358 #endif // SHARE_UTILITIES_EXCEPTIONS_HPP