1 /*
  2  * Copyright (c) 1998, 2025, 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 #include "classfile/javaClasses.hpp"
 26 #include "classfile/systemDictionary.hpp"
 27 #include "classfile/vmClasses.hpp"
 28 #include "classfile/vmSymbols.hpp"
 29 #include "compiler/compileBroker.hpp"
 30 #include "logging/log.hpp"
 31 #include "logging/logStream.hpp"
 32 #include "memory/resourceArea.hpp"
 33 #include "memory/universe.hpp"
 34 #include "oops/oop.inline.hpp"
 35 #include "runtime/atomicAccess.hpp"
 36 #include "runtime/handles.inline.hpp"
 37 #include "runtime/init.hpp"
 38 #include "runtime/java.hpp"
 39 #include "runtime/javaCalls.hpp"
 40 #include "runtime/javaThread.hpp"
 41 #include "runtime/os.hpp"
 42 #include "utilities/events.hpp"
 43 #include "utilities/exceptions.hpp"
 44 #include "utilities/utf8.hpp"
 45 
 46 // Limit exception message components to 64K (the same max as Symbols)
 47 #define MAX_LEN 65535
 48 
 49 // Implementation of ThreadShadow
 50 void check_ThreadShadow() {
 51   const ByteSize offset1 = byte_offset_of(ThreadShadow, _pending_exception);
 52   const ByteSize offset2 = Thread::pending_exception_offset();
 53   if (offset1 != offset2) fatal("ThreadShadow::_pending_exception is not positioned correctly");
 54 }
 55 
 56 
 57 void ThreadShadow::set_pending_exception(oop exception, const char* file, int line) {
 58   assert(exception != nullptr && oopDesc::is_oop(exception), "invalid exception oop");
 59   _pending_exception = exception;
 60   _exception_file    = file;
 61   _exception_line    = line;
 62 }
 63 
 64 void ThreadShadow::clear_pending_exception() {
 65   assert(_pending_exception == nullptr || !_pending_exception->is_a(vmClasses::PreemptedException_klass()),
 66          "unexpected PreemptedException, missing NoPreemptMark?");
 67   LogTarget(Debug, exceptions) lt;
 68   if (_pending_exception != nullptr && lt.is_enabled()) {
 69     ResourceMark rm;
 70     LogStream ls(lt);
 71     ls.print("Thread::clear_pending_exception: cleared exception:");
 72     _pending_exception->print_on(&ls);
 73   }
 74   _pending_exception = nullptr;
 75   _exception_file    = nullptr;
 76   _exception_line    = 0;
 77 }
 78 
 79 void ThreadShadow::clear_pending_nonasync_exception() {
 80   // Do not clear probable async exceptions.
 81   if ((_pending_exception->klass() != vmClasses::InternalError_klass() ||
 82        java_lang_InternalError::during_unsafe_access(_pending_exception) != JNI_TRUE)) {
 83     clear_pending_exception();
 84   }
 85 }
 86 
 87 void ThreadShadow::set_pending_preempted_exception() {
 88   assert(!has_pending_exception(), "");
 89   // We always install the same pre-allocated exception since we only
 90   // want to use the TRAPS mechanism to bail out from all methods until
 91   // reaching the one using the CHECK_AND_CLEAR_PREEMPTED macro.
 92   set_pending_exception(Universe::preempted_exception_instance(), __FILE__, __LINE__);
 93 }
 94 
 95 void ThreadShadow::clear_pending_preempted_exception() {
 96   assert(has_pending_exception(), "");
 97   if (pending_exception()->is_a(vmClasses::PreemptedException_klass())) {
 98     _pending_exception = nullptr;
 99     _exception_file    = nullptr;
100     _exception_line    = 0;
101   }
102 }
103 
104 #ifdef ASSERT
105 void ThreadShadow::check_preempted_exception() {
106   assert(has_pending_exception(), "");
107   assert(pending_exception()->is_a(vmClasses::PreemptedException_klass()), "should only be PreemptedException");
108 }
109 #endif
110 
111 // Implementation of Exceptions
112 
113 bool Exceptions::special_exception(JavaThread* thread, const char* file, int line, Handle h_exception, Symbol* h_name, const char* message) {
114   assert(h_exception.is_null() != (h_name == nullptr), "either exception (" PTR_FORMAT ") or "
115          "symbol (" PTR_FORMAT ") must be non-null but not both", p2i(h_exception()), p2i(h_name));
116 
117   // bootstrapping check
118   if (!Universe::is_fully_initialized()) {
119     if (h_exception.not_null()) {
120       vm_exit_during_initialization(h_exception);
121     } else if (h_name == nullptr) {
122       // at least an informative message.
123       vm_exit_during_initialization("Exception", message);
124     } else {
125       vm_exit_during_initialization(h_name, message);
126     }
127    ShouldNotReachHere();
128   }
129 
130 #ifdef ASSERT
131   // Check for trying to throw stack overflow before initialization is complete
132   // to prevent infinite recursion trying to initialize stack overflow without
133   // adequate stack space.
134   // This can happen with stress testing a large value of StackShadowPages
135   if (h_exception.not_null() && h_exception()->klass() == vmClasses::StackOverflowError_klass()) {
136     InstanceKlass* ik = InstanceKlass::cast(h_exception->klass());
137     assert(ik->is_initialized(),
138            "need to increase java_thread_min_stack_allowed calculation");
139   }
140 #endif // ASSERT
141 
142   if (h_exception.is_null() && !thread->can_call_java()) {
143     if (log_is_enabled(Info, exceptions)) {
144       ResourceMark rm(thread);
145       const char* exc_value = h_name != nullptr ? h_name->as_C_string() : "null";
146       log_info(exceptions)("Thread cannot call Java so instead of throwing exception <%.*s%s%.*s> (" PTR_FORMAT ") \n"
147                            "at [%s, line %d]\nfor thread " PTR_FORMAT ",\n"
148                            "throwing pre-allocated exception: %s",
149                            MAX_LEN, exc_value, message ? ": " : "",
150                            MAX_LEN, message ? message : "",
151                            p2i(h_exception()), file, line, p2i(thread),
152                            Universe::vm_exception()->print_value_string());
153     }
154     // We do not care what kind of exception we get for a thread which
155     // is compiling.  We just install a dummy exception object
156     thread->set_pending_exception(Universe::vm_exception(), file, line);
157     return true;
158   }
159 
160   return false;
161 }
162 
163 // This method should only be called from generated code,
164 // therefore the exception oop should be in the oopmap.
165 void Exceptions::_throw_oop(JavaThread* thread, const char* file, int line, oop exception) {
166   assert(exception != nullptr, "exception should not be null");
167   Handle h_exception(thread, exception);
168   _throw(thread, file, line, h_exception);
169 }
170 
171 void Exceptions::_throw(JavaThread* thread, const char* file, int line, Handle h_exception, const char* message) {
172   ResourceMark rm(thread);
173   assert(h_exception() != nullptr, "exception should not be null");
174 
175   // tracing (do this up front - so it works during boot strapping)
176   // Note, the print_value_string() argument is not called unless logging is enabled!
177   log_info(exceptions)("Exception <%.*s%s%.*s> (" PTR_FORMAT ") \n"
178                        "thrown [%s, line %d]\nfor thread " PTR_FORMAT,
179                        MAX_LEN, h_exception->print_value_string(),
180                        message ? ": " : "",
181                        MAX_LEN, message ? message : "",
182                        p2i(h_exception()), file, line, p2i(thread));
183   if (log_is_enabled(Info, exceptions, stacktrace)) {
184     log_exception_stacktrace(h_exception);
185   }
186 
187   // for AbortVMOnException flag
188   Exceptions::debug_check_abort(h_exception, message);
189 
190   // Check for special boot-strapping/compiler-thread handling
191   if (special_exception(thread, file, line, h_exception)) {
192     return;
193   }
194 
195   if (h_exception->is_a(vmClasses::VirtualMachineError_klass())) {
196     // Remove the ScopedValue bindings in case we got a virtual machine
197     // Error while we were trying to manipulate ScopedValue bindings.
198     thread->clear_scopedValueBindings();
199 
200     if (h_exception->is_a(vmClasses::OutOfMemoryError_klass())) {
201       count_out_of_memory_exceptions(h_exception);
202     }
203   }
204 
205   if (h_exception->is_a(vmClasses::LinkageError_klass())) {
206     AtomicAccess::inc(&_linkage_errors, memory_order_relaxed);
207   }
208 
209   assert(h_exception->is_a(vmClasses::Throwable_klass()), "exception is not a subclass of java/lang/Throwable");
210 
211   // set the pending exception
212   thread->set_pending_exception(h_exception(), file, line);
213 
214   // vm log
215   Events::log_exception(thread, h_exception, message, file, line, MAX_LEN);
216 }
217 
218 
219 void Exceptions::_throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message,
220                             Handle h_loader) {
221   // Check for special boot-strapping/compiler-thread handling
222   if (special_exception(thread, file, line, Handle(), name, message)) return;
223   // Create and throw exception
224   Handle h_cause(thread, nullptr);
225   Handle h_exception = new_exception(thread, name, message, h_cause, h_loader);
226   _throw(thread, file, line, h_exception, message);
227 }
228 
229 void Exceptions::_throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
230                                   Handle h_loader) {
231   // Check for special boot-strapping/compiler-thread handling
232   if (special_exception(thread, file, line, Handle(), name, message)) return;
233   // Create and throw exception and init cause
234   Handle h_exception = new_exception(thread, name, message, h_cause, h_loader);
235   _throw(thread, file, line, h_exception, message);
236 }
237 
238 void Exceptions::_throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause,
239                               Handle h_loader) {
240   // Check for special boot-strapping/compiler-thread handling
241   if (special_exception(thread, file, line, Handle(), name)) return;
242   // Create and throw exception
243   Handle h_exception = new_exception(thread, name, h_cause, h_loader);
244   _throw(thread, file, line, h_exception, nullptr);
245 }
246 
247 void Exceptions::_throw_args(JavaThread* thread, const char* file, int line, Symbol* name, Symbol* signature, JavaCallArguments *args) {
248   // Check for special boot-strapping/compiler-thread handling
249   if (special_exception(thread, file, line, Handle(), name, nullptr)) return;
250   // Create and throw exception
251   Handle h_loader(thread, nullptr);
252   Handle h_prot(thread, nullptr);
253   Handle exception = new_exception(thread, name, signature, args, h_loader, h_prot);
254   _throw(thread, file, line, exception);
255 }
256 
257 
258 // Methods for default parameters.
259 // NOTE: These must be here (and not in the header file) because of include circularities.
260 void Exceptions::_throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause) {
261   _throw_msg_cause(thread, file, line, name, message, h_cause, Handle());
262 }
263 void Exceptions::_throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message) {
264   _throw_msg(thread, file, line, name, message, Handle());
265 }
266 void Exceptions::_throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause) {
267   _throw_cause(thread, file, line, name, h_cause, Handle());
268 }
269 
270 
271 void Exceptions::throw_stack_overflow_exception(JavaThread* THREAD, const char* file, int line, const methodHandle& method) {
272   Handle exception;
273   if (!THREAD->has_pending_exception()) {
274     InstanceKlass* k = vmClasses::StackOverflowError_klass();
275     oop e = k->allocate_instance(CHECK);
276     exception = Handle(THREAD, e);  // fill_in_stack trace does gc
277     assert(k->is_initialized(), "need to increase java_thread_min_stack_allowed calculation");
278     if (StackTraceInThrowable) {
279       java_lang_Throwable::fill_in_stack_trace(exception, method);
280     }
281     // Increment counter for hs_err file reporting
282     AtomicAccess::inc(&Exceptions::_stack_overflow_errors, memory_order_relaxed);
283   } else {
284     // if prior exception, throw that one instead
285     exception = Handle(THREAD, THREAD->pending_exception());
286   }
287   _throw(THREAD, file, line, exception);
288 }
289 
290 // All callers are expected to have ensured that the incoming expanded format string
291 // will be within reasonable limits - specifically we will never hit the INT_MAX limit
292 // of os::vsnprintf when it tries to report how big a buffer is needed. Even so we
293 // further limit the formatted output to 1024 characters.
294 void Exceptions::fthrow(JavaThread* thread, const char* file, int line, Symbol* h_name, const char* format, ...) {
295   const int max_msg_size = 1024;
296   va_list ap;
297   va_start(ap, format);
298   char msg[max_msg_size];
299   int ret = os::vsnprintf(msg, max_msg_size, format, ap);
300   va_end(ap);
301 
302   // If ret == -1 then either there was a format conversion error, or the required buffer size
303   // exceeds INT_MAX and so couldn't be returned (undocumented behaviour of vsnprintf). Depending
304   // on the platform the buffer may be filled to its capacity (Linux), filled to the conversion
305   // that encountered the overflow (macOS), or is empty (Windows), so it is possible we
306   // have a truncated UTF-8 sequence. Similarly, if the buffer was too small and ret >= max_msg_size
307   // we may also have a truncated UTF-8 sequence. In such cases we need to fix the buffer so the UTF-8
308   // sequence is valid.
309   assert(ret != -1, "Caller should have ensured the incoming format string is size limited!");
310   if (ret == -1 || ret >= max_msg_size) {
311     int len = (int) strlen(msg);
312     if (len > 0) {
313       // Truncation will only happen if the buffer was filled by vsnprintf,
314       // otherwise vsnprintf already terminated filling it at a well-defined point.
315       // But as this is not a clearly specified area we will perform our own UTF8
316       // truncation anyway - though for those well-defined termination points it
317       // will be a no-op.
318       UTF8::truncate_to_legal_utf8((unsigned char*)msg, len + 1);
319     }
320   }
321   // UTF8::is_legal_utf8 should actually be called is_legal_utf8_class_name as the final
322   // parameter controls a check for a specific character appearing in the "name", which is only
323   // allowed for classfile versions <= 47. We pass `true` so that we allow such strings as this code
324   // know nothing about the actual string content.
325   assert(UTF8::is_legal_utf8((const unsigned char*)msg, strlen(msg), true), "must be");
326   _throw_msg(thread, file, line, h_name, msg);
327 }
328 
329 
330 // Creates an exception oop, calls the <init> method with the given signature.
331 // and returns a Handle
332 Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
333                                  Symbol* signature, JavaCallArguments *args,
334                                  Handle h_loader) {
335   assert(Universe::is_fully_initialized(),
336     "cannot be called during initialization");
337   assert(!thread->has_pending_exception(), "already has exception");
338 
339   Handle h_exception;
340 
341   // Resolve exception klass, and check for pending exception below.
342   Klass* klass = SystemDictionary::resolve_or_fail(name, h_loader, true, thread);
343 
344   if (!thread->has_pending_exception()) {
345     assert(klass != nullptr, "klass must exist");
346     // We could get here while linking or initializing a klass
347     // from a preemptable call. Don't preempt here since before
348     // the exception is propagated we might make an upcall to
349     // Java to initialize the object with the cause of exception.
350     NoPreemptMark npm(thread);
351     h_exception = JavaCalls::construct_new_instance(InstanceKlass::cast(klass),
352                                 signature,
353                                 args,
354                                 thread);
355   }
356 
357   // Check if another exception was thrown in the process, if so rethrow that one
358   if (thread->has_pending_exception()) {
359     h_exception = Handle(thread, thread->pending_exception());
360     thread->clear_pending_exception();
361   }
362   return h_exception;
363 }
364 
365 // Creates an exception oop, calls the <init> method with the given signature.
366 // and returns a Handle
367 // Initializes the cause if cause non-null
368 Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
369                                  Symbol* signature, JavaCallArguments *args,
370                                  Handle h_cause,
371                                  Handle h_loader) {
372   Handle h_exception = new_exception(thread, name, signature, args, h_loader);
373 
374   // Future: object initializer should take a cause argument
375   if (h_cause.not_null()) {
376     assert(h_cause->is_a(vmClasses::Throwable_klass()),
377         "exception cause is not a subclass of java/lang/Throwable");
378     JavaValue result1(T_OBJECT);
379     JavaCallArguments args1;
380     args1.set_receiver(h_exception);
381     args1.push_oop(h_cause);
382     JavaCalls::call_virtual(&result1, h_exception->klass(),
383                                       vmSymbols::initCause_name(),
384                                       vmSymbols::throwable_throwable_signature(),
385                                       &args1,
386                                       thread);
387   }
388 
389   // Check if another exception was thrown in the process, if so rethrow that one
390   if (thread->has_pending_exception()) {
391     h_exception = Handle(thread, thread->pending_exception());
392     thread->clear_pending_exception();
393   }
394   return h_exception;
395 }
396 
397 // Convenience method. Calls either the <init>() or <init>(Throwable) method when
398 // creating a new exception
399 Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
400                                  Handle h_cause,
401                                  Handle h_loader,
402                                  ExceptionMsgToUtf8Mode to_utf8_safe) {
403   JavaCallArguments args;
404   Symbol* signature = nullptr;
405   if (h_cause.is_null()) {
406     signature = vmSymbols::void_method_signature();
407   } else {
408     signature = vmSymbols::throwable_void_signature();
409     args.push_oop(h_cause);
410   }
411   return new_exception(thread, name, signature, &args, h_loader);
412 }
413 
414 // Convenience method. Calls either the <init>() or <init>(String) method when
415 // creating a new exception
416 Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
417                                  const char* message, Handle h_cause,
418                                  Handle h_loader,
419                                  ExceptionMsgToUtf8Mode to_utf8_safe) {
420   JavaCallArguments args;
421   Symbol* signature = nullptr;
422   if (message == nullptr) {
423     signature = vmSymbols::void_method_signature();
424   } else {
425     // There should be no pending exception. The caller is responsible for not calling
426     // this with a pending exception.
427     Handle incoming_exception;
428     if (thread->has_pending_exception()) {
429       incoming_exception = Handle(thread, thread->pending_exception());
430       thread->clear_pending_exception();
431       ResourceMark rm(thread);
432       assert(incoming_exception.is_null(), "Pending exception while throwing %s %s", name->as_C_string(), message);
433     }
434     Handle msg;
435     if (to_utf8_safe == safe_to_utf8) {
436       // Make a java UTF8 string.
437       msg = java_lang_String::create_from_str(message, thread);
438     } else {
439       // Make a java string keeping the encoding scheme of the original string.
440       msg = java_lang_String::create_from_platform_dependent_str(message, thread);
441     }
442     // If we get an exception from the allocation, prefer that to
443     // the exception we are trying to build, or the pending exception (in product mode)
444     if (thread->has_pending_exception()) {
445       Handle exception(thread, thread->pending_exception());
446       thread->clear_pending_exception();
447       return exception;
448     }
449     if (incoming_exception.not_null()) {
450       return incoming_exception;
451     }
452     args.push_oop(msg);
453     signature = vmSymbols::string_void_signature();
454   }
455   return new_exception(thread, name, signature, &args, h_cause, h_loader);
456 }
457 
458 // Another convenience method that creates handles for null class loaders and null causes.
459 // If the last parameter 'to_utf8_mode' is safe_to_utf8,
460 // it means we can safely ignore the encoding scheme of the message string and
461 // convert it directly to a java UTF8 string. Otherwise, we need to take the
462 // encoding scheme of the string into account. One thing we should do at some
463 // point is to push this flag down to class java_lang_String since other
464 // classes may need similar functionalities.
465 Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
466                                  const char* message,
467                                  ExceptionMsgToUtf8Mode to_utf8_safe) {
468 
469   Handle h_loader;
470   Handle h_cause;
471   return Exceptions::new_exception(thread, name, message, h_cause, h_loader,
472                                    to_utf8_safe);
473 }
474 
475 // invokedynamic uses wrap_dynamic_exception for:
476 //    - bootstrap method resolution
477 //    - post call to MethodHandleNatives::linkCallSite
478 // dynamically computed constant uses wrap_dynamic_exception for:
479 //    - bootstrap method resolution
480 //    - post call to MethodHandleNatives::linkDynamicConstant
481 void Exceptions::wrap_dynamic_exception(bool is_indy, JavaThread* THREAD) {
482   if (THREAD->has_pending_exception()) {
483     bool log_indy = log_is_enabled(Debug, methodhandles, indy) && is_indy;
484     bool log_condy = log_is_enabled(Debug, methodhandles, condy) && !is_indy;
485     LogStreamHandle(Debug, methodhandles, indy) lsh_indy;
486     LogStreamHandle(Debug, methodhandles, condy) lsh_condy;
487     LogStream* ls = nullptr;
488     if (log_indy) {
489       ls = &lsh_indy;
490     } else if (log_condy) {
491       ls = &lsh_condy;
492     }
493     oop exception = THREAD->pending_exception();
494 
495     // See the "Linking Exceptions" section for the invokedynamic instruction
496     // in JVMS 6.5.
497     if (exception->is_a(vmClasses::Error_klass())) {
498       // Pass through an Error, including BootstrapMethodError, any other form
499       // of linkage error, or say OutOfMemoryError
500       if (ls != nullptr) {
501         ResourceMark rm(THREAD);
502         ls->print_cr("bootstrap method invocation wraps BSME around " PTR_FORMAT, p2i(exception));
503         exception->print_on(ls);
504       }
505       return;
506     }
507 
508     // Otherwise wrap the exception in a BootstrapMethodError
509     if (ls != nullptr) {
510       ResourceMark rm(THREAD);
511       ls->print_cr("%s throws BSME for " PTR_FORMAT, is_indy ? "invokedynamic" : "dynamic constant", p2i(exception));
512       exception->print_on(ls);
513     }
514     Handle nested_exception(THREAD, exception);
515     THREAD->clear_pending_exception();
516     THROW_CAUSE(vmSymbols::java_lang_BootstrapMethodError(), nested_exception)
517   }
518 }
519 
520 // Exception counting for hs_err file
521 volatile int Exceptions::_stack_overflow_errors = 0;
522 volatile int Exceptions::_linkage_errors = 0;
523 volatile int Exceptions::_out_of_memory_error_java_heap_errors = 0;
524 volatile int Exceptions::_out_of_memory_error_metaspace_errors = 0;
525 volatile int Exceptions::_out_of_memory_error_class_metaspace_errors = 0;
526 
527 void Exceptions::count_out_of_memory_exceptions(Handle exception) {
528   if (Universe::is_out_of_memory_error_metaspace(exception())) {
529      AtomicAccess::inc(&_out_of_memory_error_metaspace_errors, memory_order_relaxed);
530   } else if (Universe::is_out_of_memory_error_class_metaspace(exception())) {
531      AtomicAccess::inc(&_out_of_memory_error_class_metaspace_errors, memory_order_relaxed);
532   } else {
533      // everything else reported as java heap OOM
534      AtomicAccess::inc(&_out_of_memory_error_java_heap_errors, memory_order_relaxed);
535   }
536 }
537 
538 static void print_oom_count(outputStream* st, const char *err, int count) {
539   if (count > 0) {
540     st->print_cr("OutOfMemoryError %s=%d", err, count);
541   }
542 }
543 
544 bool Exceptions::has_exception_counts() {
545   return (_stack_overflow_errors + _out_of_memory_error_java_heap_errors +
546          _out_of_memory_error_metaspace_errors + _out_of_memory_error_class_metaspace_errors) > 0;
547 }
548 
549 void Exceptions::print_exception_counts_on_error(outputStream* st) {
550   print_oom_count(st, "java_heap_errors", _out_of_memory_error_java_heap_errors);
551   print_oom_count(st, "metaspace_errors", _out_of_memory_error_metaspace_errors);
552   print_oom_count(st, "class_metaspace_errors", _out_of_memory_error_class_metaspace_errors);
553   if (_stack_overflow_errors > 0) {
554     st->print_cr("StackOverflowErrors=%d", _stack_overflow_errors);
555   }
556   if (_linkage_errors > 0) {
557     st->print_cr("LinkageErrors=%d", _linkage_errors);
558   }
559 }
560 
561 // Implementation of ExceptionMark
562 
563 ExceptionMark::ExceptionMark(JavaThread* thread) {
564   assert(thread == JavaThread::current(), "must be");
565   _thread  = thread;
566   check_no_pending_exception();
567 }
568 
569 ExceptionMark::ExceptionMark() {
570   _thread = JavaThread::current();
571   check_no_pending_exception();
572 }
573 
574 inline void ExceptionMark::check_no_pending_exception() {
575   if (_thread->has_pending_exception()) {
576     oop exception = _thread->pending_exception();
577     _thread->clear_pending_exception(); // Needed to avoid infinite recursion
578     ResourceMark rm;
579     exception->print();
580     fatal("ExceptionMark constructor expects no pending exceptions");
581   }
582 }
583 
584 
585 ExceptionMark::~ExceptionMark() {
586   if (_thread->has_pending_exception()) {
587     Handle exception(_thread, _thread->pending_exception());
588     _thread->clear_pending_exception(); // Needed to avoid infinite recursion
589     if (is_init_completed()) {
590       ResourceMark rm;
591       exception->print();
592       fatal("ExceptionMark destructor expects no pending exceptions");
593     } else {
594       vm_exit_during_initialization(exception);
595     }
596   }
597 }
598 
599 // ----------------------------------------------------------------------------------------
600 
601 // caller frees value_string if necessary
602 void Exceptions::debug_check_abort(const char *value_string, const char* message) {
603   if (AbortVMOnException != nullptr && value_string != nullptr &&
604       strstr(value_string, AbortVMOnException)) {
605     if (AbortVMOnExceptionMessage == nullptr || (message != nullptr &&
606         strstr(message, AbortVMOnExceptionMessage))) {
607       if (message == nullptr) {
608         fatal("Saw %s, aborting", value_string);
609       } else {
610         fatal("Saw %s: %s, aborting", value_string, message);
611       }
612     }
613   }
614 }
615 
616 void Exceptions::debug_check_abort(Handle exception, const char* message) {
617   if (AbortVMOnException != nullptr) {
618     debug_check_abort_helper(exception, message);
619   }
620 }
621 
622 void Exceptions::debug_check_abort_helper(Handle exception, const char* message) {
623   ResourceMark rm;
624   if (message == nullptr && exception->is_a(vmClasses::Throwable_klass())) {
625     oop msg = java_lang_Throwable::message(exception());
626     if (msg != nullptr) {
627       message = java_lang_String::as_utf8_string(msg);
628     }
629   }
630   debug_check_abort(exception()->klass()->external_name(), message);
631 }
632 
633 // for logging exceptions
634 void Exceptions::log_exception(Handle exception, const char* message) {
635   ResourceMark rm;
636   const char* detail_message = java_lang_Throwable::message_as_utf8(exception());
637   if (detail_message != nullptr) {
638     log_info(exceptions)("Exception <%.*s: %.*s>\n thrown in %.*s",
639                          MAX_LEN, exception->print_value_string(),
640                          MAX_LEN, detail_message,
641                          MAX_LEN, message);
642   } else {
643     log_info(exceptions)("Exception <%.*s>\n thrown in %.*s",
644                          MAX_LEN, exception->print_value_string(),
645                          MAX_LEN, message);
646   }
647 }
648 
649 // This is called from InterpreterRuntime::exception_handler_for_exception(), which is the only
650 // easy way to be notified in the VM that an _athrow bytecode has been executed. (The alternative
651 // would be to add hooks into the interpreter and compiler, for all platforms ...).
652 //
653 // Unfortunately, InterpreterRuntime::exception_handler_for_exception() is called for every level
654 // of the Java stack when looking for an exception handler. To avoid excessive output,
655 // we print the stack only when the bci points to an _athrow bytecode.
656 //
657 // NOTE: exceptions that are NOT thrown by _athrow are handled by Exceptions::special_exception()
658 // and Exceptions::_throw()).
659 void Exceptions::log_exception_stacktrace(Handle exception, methodHandle method, int bci) {
660   if (!method->is_native() && (Bytecodes::Code) *method->bcp_from(bci) == Bytecodes::_athrow) {
661     // TODO: try to find a way to avoid repeated stacktraces when an exception gets re-thrown
662     // by a finally block
663     log_exception_stacktrace(exception);
664   }
665 }
666 
667 // This should be called only from a live Java thread.
668 void Exceptions::log_exception_stacktrace(Handle exception) {
669   LogStreamHandle(Info, exceptions, stacktrace) st;
670   ResourceMark rm;
671   const char* detail_message = java_lang_Throwable::message_as_utf8(exception());
672   if (detail_message != nullptr) {
673     st.print_cr("Exception <%.*s: %.*s>",
674                 MAX_LEN, exception->print_value_string(),
675                 MAX_LEN, detail_message);
676   } else {
677     st.print_cr("Exception <%.*s>",
678                 MAX_LEN, exception->print_value_string());
679   }
680   JavaThread* t = JavaThread::current();
681   if (t->has_last_Java_frame()) {
682     t->print_active_stack_on(&st);
683   } else {
684     st.print_cr("(Cannot print stracktrace)");
685   }
686 }