/*

 * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "compiler/compileBroker.hpp"

#include "logging/log.hpp"

#include "memory/resourceArea.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/init.hpp"

#include "runtime/java.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/thread.inline.hpp"

#include "runtime/threadCritical.hpp"

#include "utilities/events.hpp"

#include "utilities/exceptions.hpp"

// Implementation of ThreadShadow

void check_ThreadShadow() {

  const ByteSize offset1 = byte_offset_of(ThreadShadow, _pending_exception);

  const ByteSize offset2 = Thread::pending_exception_offset();

  if (offset1 != offset2) fatal("ThreadShadow::_pending_exception is not positioned correctly");

}

void ThreadShadow::set_pending_exception(oop exception, const char* file, int line) {

  assert(exception != NULL && exception->is_oop(), "invalid exception oop");

  _pending_exception = exception;

  _exception_file    = file;

  _exception_line    = line;

}

void ThreadShadow::clear_pending_exception() {

  if (_pending_exception != NULL && log_is_enabled(Debug, exceptions)) {

    ResourceMark rm;

    outputStream* logst = Log(exceptions)::debug_stream();

    logst->print("Thread::clear_pending_exception: cleared exception:");

    _pending_exception->print_on(logst);

  }

  _pending_exception = NULL;

  _exception_file    = NULL;

  _exception_line    = 0;

}

// Implementation of Exceptions

bool Exceptions::special_exception(Thread* thread, const char* file, int line, Handle h_exception) {

  // bootstrapping check

  if (!Universe::is_fully_initialized()) {

   vm_exit_during_initialization(h_exception);

   ShouldNotReachHere();

  }

#ifdef ASSERT

  // Check for trying to throw stack overflow before initialization is complete

  // to prevent infinite recursion trying to initialize stack overflow without

  // adequate stack space.

  // This can happen with stress testing a large value of StackShadowPages

  if (h_exception()->klass() == SystemDictionary::StackOverflowError_klass()) {

    InstanceKlass* ik = InstanceKlass::cast(h_exception->klass());

    assert(ik->is_initialized(),

           "need to increase java_thread_min_stack_allowed calculation");

  }

#endif // ASSERT

  if (thread->is_VM_thread()

      || !thread->can_call_java()

      || DumpSharedSpaces ) {

    // We do not care what kind of exception we get for the vm-thread or a thread which

    // is compiling.  We just install a dummy exception object

    //

    // We also cannot throw a proper exception when dumping, because we cannot run

    // Java bytecodes now. A dummy exception will suffice.

    thread->set_pending_exception(Universe::vm_exception(), file, line);

    return true;

  }

  return false;

}

bool Exceptions::special_exception(Thread* thread, const char* file, int line, Symbol* h_name, const char* message) {

  // bootstrapping check

  if (!Universe::is_fully_initialized()) {

    if (h_name == NULL) {

      // atleast an informative message.

      vm_exit_during_initialization("Exception", message);

    } else {

      vm_exit_during_initialization(h_name, message);

    }

    ShouldNotReachHere();

  }

  if (thread->is_VM_thread()

      || !thread->can_call_java()

      || DumpSharedSpaces ) {

    // We do not care what kind of exception we get for the vm-thread or a thread which

    // is compiling.  We just install a dummy exception object

    //

    // We also cannot throw a proper exception when dumping, because we cannot run

    // Java bytecodes now. A dummy exception will suffice.

    thread->set_pending_exception(Universe::vm_exception(), file, line);

    return true;

  }

  return false;

}

// This method should only be called from generated code,

// therefore the exception oop should be in the oopmap.

void Exceptions::_throw_oop(Thread* thread, const char* file, int line, oop exception) {

  assert(exception != NULL, "exception should not be NULL");

  Handle h_exception = Handle(thread, exception);

  _throw(thread, file, line, h_exception);

}

void Exceptions::_throw(Thread* thread, const char* file, int line, Handle h_exception, const char* message) {

  ResourceMark rm;

  assert(h_exception() != NULL, "exception should not be NULL");

  // tracing (do this up front - so it works during boot strapping)

  log_info(exceptions)("Exception <%s%s%s> (" INTPTR_FORMAT ") \n"

                       "thrown [%s, line %d]\nfor thread " INTPTR_FORMAT,

                       h_exception->print_value_string(),

                       message ? ": " : "", message ? message : "",

                       p2i(h_exception()), file, line, p2i(thread));

  // for AbortVMOnException flag

  Exceptions::debug_check_abort(h_exception, message);

  // Check for special boot-strapping/vm-thread handling

  if (special_exception(thread, file, line, h_exception)) {

    return;

  }

  if (h_exception->is_a(SystemDictionary::OutOfMemoryError_klass())) {

    count_out_of_memory_exceptions(h_exception);

  }

  assert(h_exception->is_a(SystemDictionary::Throwable_klass()), "exception is not a subclass of java/lang/Throwable");

  // set the pending exception

  thread->set_pending_exception(h_exception(), file, line);

  // vm log

  if (LogEvents){

    Events::log_exception(thread, "Exception <%s%s%s> (" INTPTR_FORMAT ") thrown at [%s, line %d]",

                          h_exception->print_value_string(), message ? ": " : "", message ? message : "",

                          p2i(h_exception()), file, line);

  }

}

void Exceptions::_throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message,

                            Handle h_loader, Handle h_protection_domain) {

  // Check for special boot-strapping/vm-thread handling

  if (special_exception(thread, file, line, name, message)) return;

  // Create and throw exception

  Handle h_cause(thread, NULL);

  Handle h_exception = new_exception(thread, name, message, h_cause, h_loader, h_protection_domain);

  _throw(thread, file, line, h_exception, message);

}

void Exceptions::_throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,

                                  Handle h_loader, Handle h_protection_domain) {

  // Check for special boot-strapping/vm-thread handling

  if (special_exception(thread, file, line, name, message)) return;

  // Create and throw exception and init cause

  Handle h_exception = new_exception(thread, name, message, h_cause, h_loader, h_protection_domain);

  _throw(thread, file, line, h_exception, message);

}

void Exceptions::_throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause,

                              Handle h_loader, Handle h_protection_domain) {

  // Check for special boot-strapping/vm-thread handling

  if (special_exception(thread, file, line, h_cause)) return;

  // Create and throw exception

  Handle h_exception = new_exception(thread, name, h_cause, h_loader, h_protection_domain);

  _throw(thread, file, line, h_exception, NULL);

}

void Exceptions::_throw_args(Thread* thread, const char* file, int line, Symbol* name, Symbol* signature, JavaCallArguments *args) {

  // Check for special boot-strapping/vm-thread handling

  if (special_exception(thread, file, line, name, NULL)) return;

  // Create and throw exception

  Handle h_loader(thread, NULL);

  Handle h_prot(thread, NULL);

  Handle exception = new_exception(thread, name, signature, args, h_loader, h_prot);

  _throw(thread, file, line, exception);

}

// Methods for default parameters.

// NOTE: These must be here (and not in the header file) because of include circularities.

void Exceptions::_throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause) {

  _throw_msg_cause(thread, file, line, name, message, h_cause, Handle(thread, NULL), Handle(thread, NULL));

}

void Exceptions::_throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message) {

  _throw_msg(thread, file, line, name, message, Handle(thread, NULL), Handle(thread, NULL));

}

void Exceptions::_throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause) {

  _throw_cause(thread, file, line, name, h_cause, Handle(thread, NULL), Handle(thread, NULL));

}

void Exceptions::throw_stack_overflow_exception(Thread* THREAD, const char* file, int line, const methodHandle& method) {

  Handle exception;

  if (!THREAD->has_pending_exception()) {

    Klass* k = SystemDictionary::StackOverflowError_klass();

    oop e = InstanceKlass::cast(k)->allocate_instance(CHECK);

    exception = Handle(THREAD, e);  // fill_in_stack trace does gc

    assert(InstanceKlass::cast(k)->is_initialized(), "need to increase java_thread_min_stack_allowed calculation");

    if (StackTraceInThrowable) {

      java_lang_Throwable::fill_in_stack_trace(exception, method());

    }

    // Increment counter for hs_err file reporting

    Atomic::inc(&Exceptions::_stack_overflow_errors);

  } else {

    // if prior exception, throw that one instead

    exception = Handle(THREAD, THREAD->pending_exception());

  }

  _throw(THREAD, file, line, exception);

}

void Exceptions::fthrow(Thread* thread, const char* file, int line, Symbol* h_name, const char* format, ...) {

  const int max_msg_size = 1024;

  va_list ap;

  va_start(ap, format);

  char msg[max_msg_size];

  vsnprintf(msg, max_msg_size, format, ap);

  msg[max_msg_size-1] = '\0';

  va_end(ap);

  _throw_msg(thread, file, line, h_name, msg);

}

// Creates an exception oop, calls the <init> method with the given signature.

// and returns a Handle

Handle Exceptions::new_exception(Thread *thread, Symbol* name,

                                 Symbol* signature, JavaCallArguments *args,

                                 Handle h_loader, Handle h_protection_domain) {

  assert(Universe::is_fully_initialized(),

    "cannot be called during initialization");

  assert(thread->is_Java_thread(), "can only be called by a Java thread");

  assert(!thread->has_pending_exception(), "already has exception");

  Handle h_exception;

  // Resolve exception klass

  Klass* ik = SystemDictionary::resolve_or_fail(name, h_loader, h_protection_domain, true, thread);

  instanceKlassHandle klass(thread, ik);

  if (!thread->has_pending_exception()) {

    assert(klass.not_null(), "klass must exist");

    // We are about to create an instance - so make sure that klass is initialized

    klass->initialize(thread);

    if (!thread->has_pending_exception()) {

      // Allocate new exception

      h_exception = klass->allocate_instance_handle(thread);

      if (!thread->has_pending_exception()) {

        JavaValue result(T_VOID);

        args->set_receiver(h_exception);

        // Call constructor

        JavaCalls::call_special(&result, klass,

                                         vmSymbols::object_initializer_name(),

                                         signature,

                                         args,

                                         thread);

      }

    }

  }

  // Check if another exception was thrown in the process, if so rethrow that one

  if (thread->has_pending_exception()) {

    h_exception = Handle(thread, thread->pending_exception());

    thread->clear_pending_exception();

  }

  return h_exception;

}

// Creates an exception oop, calls the <init> method with the given signature.

// and returns a Handle

// Initializes the cause if cause non-null

Handle Exceptions::new_exception(Thread *thread, Symbol* name,

                                 Symbol* signature, JavaCallArguments *args,

                                 Handle h_cause,

                                 Handle h_loader, Handle h_protection_domain) {

  Handle h_exception = new_exception(thread, name, signature, args, h_loader, h_protection_domain);

  // Future: object initializer should take a cause argument

  if (h_cause.not_null()) {

    assert(h_cause->is_a(SystemDictionary::Throwable_klass()),

        "exception cause is not a subclass of java/lang/Throwable");

    JavaValue result1(T_OBJECT);

    JavaCallArguments args1;

    args1.set_receiver(h_exception);

    args1.push_oop(h_cause);

    JavaCalls::call_virtual(&result1, h_exception->klass(),

                                      vmSymbols::initCause_name(),

                                      vmSymbols::throwable_throwable_signature(),

                                      &args1,

                                      thread);

  }

  // Check if another exception was thrown in the process, if so rethrow that one

  if (thread->has_pending_exception()) {

    h_exception = Handle(thread, thread->pending_exception());

    thread->clear_pending_exception();

  }

  return h_exception;

}

// Convenience method. Calls either the <init>() or <init>(Throwable) method when

// creating a new exception

Handle Exceptions::new_exception(Thread* thread, Symbol* name,

                                 Handle h_cause,

                                 Handle h_loader, Handle h_protection_domain,

                                 ExceptionMsgToUtf8Mode to_utf8_safe) {

  JavaCallArguments args;

  Symbol* signature = NULL;

  if (h_cause.is_null()) {

    signature = vmSymbols::void_method_signature();

  } else {

    signature = vmSymbols::throwable_void_signature();

    args.push_oop(h_cause);

  }

  return new_exception(thread, name, signature, &args, h_loader, h_protection_domain);

}

// Convenience method. Calls either the <init>() or <init>(String) method when

// creating a new exception

Handle Exceptions::new_exception(Thread* thread, Symbol* name,

                                 const char* message, Handle h_cause,

                                 Handle h_loader, Handle h_protection_domain,

                                 ExceptionMsgToUtf8Mode to_utf8_safe) {

  JavaCallArguments args;

  Symbol* signature = NULL;

  if (message == NULL) {

    signature = vmSymbols::void_method_signature();

  } else {

    // We want to allocate storage, but we can't do that if there's

    // a pending exception, so we preserve any pending exception

    // around the allocation.

    // If we get an exception from the allocation, prefer that to

    // the exception we are trying to build, or the pending exception.

    // This is sort of like what PRESERVE_EXCEPTION_MARK does, except

    // for the preferencing and the early returns.

    Handle incoming_exception(thread, NULL);

    if (thread->has_pending_exception()) {

      incoming_exception = Handle(thread, thread->pending_exception());

      thread->clear_pending_exception();

    }

    Handle msg;

    if (to_utf8_safe == safe_to_utf8) {

      // Make a java UTF8 string.

      msg = java_lang_String::create_from_str(message, thread);

    } else {

      // Make a java string keeping the encoding scheme of the original string.

      msg = java_lang_String::create_from_platform_dependent_str(message, thread);

    }

    if (thread->has_pending_exception()) {

      Handle exception(thread, thread->pending_exception());

      thread->clear_pending_exception();

      return exception;

    }

    if (incoming_exception.not_null()) {

      return incoming_exception;

    }

    args.push_oop(msg);

    signature = vmSymbols::string_void_signature();

  }

  return new_exception(thread, name, signature, &args, h_cause, h_loader, h_protection_domain);

}

// Another convenience method that creates handles for null class loaders and

// protection domains and null causes.

// If the last parameter 'to_utf8_mode' is safe_to_utf8,

// it means we can safely ignore the encoding scheme of the message string and

// convert it directly to a java UTF8 string. Otherwise, we need to take the

// encoding scheme of the string into account. One thing we should do at some

// point is to push this flag down to class java_lang_String since other

// classes may need similar functionalities.

Handle Exceptions::new_exception(Thread* thread, Symbol* name,

                                 const char* message,

                                 ExceptionMsgToUtf8Mode to_utf8_safe) {

  Handle       h_loader(thread, NULL);

  Handle       h_prot(thread, NULL);

  Handle       h_cause(thread, NULL);

  return Exceptions::new_exception(thread, name, message, h_cause, h_loader,

                                   h_prot, to_utf8_safe);

}

// Exception counting for hs_err file

volatile int Exceptions::_stack_overflow_errors = 0;

volatile int Exceptions::_out_of_memory_error_java_heap_errors = 0;

volatile int Exceptions::_out_of_memory_error_metaspace_errors = 0;

volatile int Exceptions::_out_of_memory_error_class_metaspace_errors = 0;

void Exceptions::count_out_of_memory_exceptions(Handle exception) {

  if (exception() == Universe::out_of_memory_error_metaspace()) {

     Atomic::inc(&_out_of_memory_error_metaspace_errors);

  } else if (exception() == Universe::out_of_memory_error_class_metaspace()) {

     Atomic::inc(&_out_of_memory_error_class_metaspace_errors);

  } else {

     // everything else reported as java heap OOM

     Atomic::inc(&_out_of_memory_error_java_heap_errors);

  }

}

void print_oom_count(outputStream* st, const char *err, int count) {

  if (count > 0) {

    st->print_cr("OutOfMemoryError %s=%d", err, count);

  }

}

bool Exceptions::has_exception_counts() {

  return (_stack_overflow_errors + _out_of_memory_error_java_heap_errors +

         _out_of_memory_error_metaspace_errors + _out_of_memory_error_class_metaspace_errors) > 0;

}

void Exceptions::print_exception_counts_on_error(outputStream* st) {

  print_oom_count(st, "java_heap_errors", _out_of_memory_error_java_heap_errors);

  print_oom_count(st, "metaspace_errors", _out_of_memory_error_metaspace_errors);

  print_oom_count(st, "class_metaspace_errors", _out_of_memory_error_class_metaspace_errors);

  if (_stack_overflow_errors > 0) {

    st->print_cr("StackOverflowErrors=%d", _stack_overflow_errors);

  }

}

// Implementation of ExceptionMark

ExceptionMark::ExceptionMark(Thread*& thread) {

  thread     = Thread::current();

  _thread    = thread;

  if (_thread->has_pending_exception()) {

    oop exception = _thread->pending_exception();

    _thread->clear_pending_exception(); // Needed to avoid infinite recursion

    exception->print();

    fatal("ExceptionMark constructor expects no pending exceptions");

  }

}

ExceptionMark::~ExceptionMark() {

  if (_thread->has_pending_exception()) {

    Handle exception(_thread, _thread->pending_exception());

    _thread->clear_pending_exception(); // Needed to avoid infinite recursion

    if (is_init_completed()) {

      exception->print();

      fatal("ExceptionMark destructor expects no pending exceptions");

    } else {

      vm_exit_during_initialization(exception);

    }

  }

}

// ----------------------------------------------------------------------------------------

// caller frees value_string if necessary

void Exceptions::debug_check_abort(const char *value_string, const char* message) {

  if (AbortVMOnException != NULL && value_string != NULL &&

      strstr(value_string, AbortVMOnException)) {

    if (AbortVMOnExceptionMessage == NULL || (message != NULL &&

        strstr(message, AbortVMOnExceptionMessage))) {

      fatal("Saw %s, aborting", value_string);

    }

  }

}

void Exceptions::debug_check_abort(Handle exception, const char* message) {

  if (AbortVMOnException != NULL) {

    debug_check_abort_helper(exception, message);

  }

}

void Exceptions::debug_check_abort_helper(Handle exception, const char* message) {

  ResourceMark rm;

  if (message == NULL && exception->is_a(SystemDictionary::Throwable_klass())) {

    oop msg = java_lang_Throwable::message(exception);

    if (msg != NULL) {

      message = java_lang_String::as_utf8_string(msg);

    }

  }

  debug_check_abort(exception()->klass()->external_name(), message);