/*

 * Copyright (c) 1999, 2017, 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 "jvmci/jvmciEnv.hpp"

#include "classfile/javaAssertions.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "code/codeCache.hpp"

#include "code/scopeDesc.hpp"

#include "runtime/sweeper.hpp"

#include "compiler/compileBroker.hpp"

#include "compiler/compileLog.hpp"

#include "compiler/compilerOracle.hpp"

#include "interpreter/linkResolver.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/oopFactory.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.inline.hpp"

#include "oops/methodData.hpp"

#include "oops/objArrayKlass.hpp"

#include "oops/oop.inline.hpp"

#include "prims/jvmtiExport.hpp"

#include "runtime/init.hpp"

#include "runtime/reflection.hpp"

#include "runtime/sharedRuntime.hpp"

#include "utilities/dtrace.hpp"

#include "jvmci/jvmciRuntime.hpp"

#include "jvmci/jvmciJavaClasses.hpp"

JVMCIEnv::JVMCIEnv(CompileTask* task, int system_dictionary_modification_counter):

  _task(task),

  _system_dictionary_modification_counter(system_dictionary_modification_counter),

  _failure_reason(NULL),

  _retryable(true)

{

  // Get Jvmti capabilities under lock to get consistent values.

  MutexLocker mu(JvmtiThreadState_lock);

  _jvmti_can_hotswap_or_post_breakpoint = JvmtiExport::can_hotswap_or_post_breakpoint();

  _jvmti_can_access_local_variables     = JvmtiExport::can_access_local_variables();

  _jvmti_can_post_on_exceptions         = JvmtiExport::can_post_on_exceptions();

}

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

// Note: the logic of this method should mirror the logic of

// constantPoolOopDesc::verify_constant_pool_resolve.

bool JVMCIEnv::check_klass_accessibility(Klass* accessing_klass, Klass* resolved_klass) {

  if (accessing_klass->is_objArray_klass()) {

    accessing_klass = ObjArrayKlass::cast(accessing_klass)->bottom_klass();

  }

  if (!accessing_klass->is_instance_klass()) {

    return true;

  }

  if (resolved_klass->is_objArray_klass()) {

    // Find the element klass, if this is an array.

    resolved_klass = ObjArrayKlass::cast(resolved_klass)->bottom_klass();

  }

  if (resolved_klass->is_instance_klass()) {

    Reflection::VerifyClassAccessResults result =

      Reflection::verify_class_access(accessing_klass, InstanceKlass::cast(resolved_klass), true);

    return result == Reflection::ACCESS_OK;

  }

  return true;

}

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

Klass* JVMCIEnv::get_klass_by_name_impl(Klass* accessing_klass,

                                        const constantPoolHandle& cpool,

                                        Symbol* sym,

                                        bool require_local) {

  JVMCI_EXCEPTION_CONTEXT;

  // Now we need to check the SystemDictionary

  if (sym->byte_at(0) == 'L' &&

    sym->byte_at(sym->utf8_length()-1) == ';') {

    // This is a name from a signature.  Strip off the trimmings.

    // Call recursive to keep scope of strippedsym.

    TempNewSymbol strippedsym = SymbolTable::new_symbol(sym->as_utf8()+1,

                    sym->utf8_length()-2,

                    CHECK_NULL);

    return get_klass_by_name_impl(accessing_klass, cpool, strippedsym, require_local);

  }

  Handle loader(THREAD, (oop)NULL);

  Handle domain(THREAD, (oop)NULL);

  if (accessing_klass != NULL) {

    loader = Handle(THREAD, accessing_klass->class_loader());

    domain = Handle(THREAD, accessing_klass->protection_domain());

  }

  Klass* found_klass = NULL;

  {

    ttyUnlocker ttyul;  // release tty lock to avoid ordering problems

    MutexLocker ml(Compile_lock);

    if (!require_local) {

      found_klass = SystemDictionary::find_constrained_instance_or_array_klass(sym, loader, CHECK_NULL);

    } else {

      found_klass = SystemDictionary::find_instance_or_array_klass(sym, loader, domain, CHECK_NULL);

    }

  }

  // If we fail to find an array klass, look again for its element type.

  // The element type may be available either locally or via constraints.

  // In either case, if we can find the element type in the system dictionary,

  // we must build an array type around it.  The CI requires array klasses

  // to be loaded if their element klasses are loaded, except when memory

  // is exhausted.

  if (sym->byte_at(0) == '[' &&

      (sym->byte_at(1) == '[' || sym->byte_at(1) == 'L')) {

    // We have an unloaded array.

    // Build it on the fly if the element class exists.

    TempNewSymbol elem_sym = SymbolTable::new_symbol(sym->as_utf8()+1,

                                                 sym->utf8_length()-1,

                                                 CHECK_NULL);

    // Get element Klass recursively.

    Klass* elem_klass =

      get_klass_by_name_impl(accessing_klass,

                             cpool,

                             elem_sym,

                             require_local);

    if (elem_klass != NULL) {

      // Now make an array for it

      return elem_klass->array_klass(CHECK_NULL);

    }

  }

  if (found_klass == NULL && !cpool.is_null() && cpool->has_preresolution()) {

    // Look inside the constant pool for pre-resolved class entries.

    for (int i = cpool->length() - 1; i >= 1; i--) {

      if (cpool->tag_at(i).is_klass()) {

        Klass*  kls = cpool->resolved_klass_at(i);

        if (kls->name() == sym) {

          return kls;

        }

      }

    }

  }

  return found_klass;

}

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

Klass* JVMCIEnv::get_klass_by_name(Klass* accessing_klass,

                                  Symbol* klass_name,

                                  bool require_local) {

  ResourceMark rm;

  constantPoolHandle cpool;

  return get_klass_by_name_impl(accessing_klass,

                                cpool,

                                klass_name,

                                require_local);

}

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

// Implementation of get_klass_by_index.

Klass* JVMCIEnv::get_klass_by_index_impl(const constantPoolHandle& cpool,

                                        int index,

                                        bool& is_accessible,

                                        Klass* accessor) {

  JVMCI_EXCEPTION_CONTEXT;

  Klass* klass = ConstantPool::klass_at_if_loaded(cpool, index);

  Symbol* klass_name = NULL;

  if (klass == NULL) {

    klass_name = cpool->klass_name_at(index);

  }

  if (klass == NULL) {

    // Not found in constant pool.  Use the name to do the lookup.

    Klass* k = get_klass_by_name_impl(accessor,

                                      cpool,

                                      klass_name,

                                      false);

    // Calculate accessibility the hard way.

    if (k == NULL) {

      is_accessible = false;

    } else if (k->class_loader() != accessor->class_loader() &&

               get_klass_by_name_impl(accessor, cpool, k->name(), true) == NULL) {

      // Loaded only remotely.  Not linked yet.

      is_accessible = false;

    } else {

      // Linked locally, and we must also check public/private, etc.

      is_accessible = check_klass_accessibility(accessor, k);

    }

    if (!is_accessible) {

      return NULL;

    }

    return k;

  }

  // It is known to be accessible, since it was found in the constant pool.

  is_accessible = true;

  return klass;

}

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

// Get a klass from the constant pool.

Klass* JVMCIEnv::get_klass_by_index(const constantPoolHandle& cpool,

                                    int index,

                                    bool& is_accessible,

                                    Klass* accessor) {

  ResourceMark rm;

  return get_klass_by_index_impl(cpool, index, is_accessible, accessor);

}

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

// Implementation of get_field_by_index.

//

// Implementation note: the results of field lookups are cached

// in the accessor klass.

void JVMCIEnv::get_field_by_index_impl(InstanceKlass* klass, fieldDescriptor& field_desc,

                                        int index) {

  JVMCI_EXCEPTION_CONTEXT;

  assert(klass->is_linked(), "must be linked before using its constant-pool");

  constantPoolHandle cpool(thread, klass->constants());

  // Get the field's name, signature, and type.

  Symbol* name  = cpool->name_ref_at(index);

  int nt_index = cpool->name_and_type_ref_index_at(index);

  int sig_index = cpool->signature_ref_index_at(nt_index);

  Symbol* signature = cpool->symbol_at(sig_index);

  // Get the field's declared holder.

  int holder_index = cpool->klass_ref_index_at(index);

  bool holder_is_accessible;

  Klass* declared_holder = get_klass_by_index(cpool, holder_index,

                                              holder_is_accessible,

                                              klass);

  // The declared holder of this field may not have been loaded.

  // Bail out with partial field information.

  if (!holder_is_accessible) {

    return;

  }

  // Perform the field lookup.

  Klass*  canonical_holder =

    InstanceKlass::cast(declared_holder)->find_field(name, signature, &field_desc);

  if (canonical_holder == NULL) {

    return;

  }

  assert(canonical_holder == field_desc.field_holder(), "just checking");

}

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

// Get a field by index from a klass's constant pool.

void JVMCIEnv::get_field_by_index(InstanceKlass* accessor, fieldDescriptor& fd, int index) {

  ResourceMark rm;

  return get_field_by_index_impl(accessor, fd, index);

}

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

// Perform an appropriate method lookup based on accessor, holder,

// name, signature, and bytecode.

methodHandle JVMCIEnv::lookup_method(InstanceKlass* accessor,

                               Klass*         holder,

                               Symbol*        name,

                               Symbol*        sig,

                               Bytecodes::Code bc,

                               constantTag   tag) {

  // Accessibility checks are performed in JVMCIEnv::get_method_by_index_impl().

  assert(check_klass_accessibility(accessor, holder), "holder not accessible");

  methodHandle dest_method;

  LinkInfo link_info(holder, name, sig, accessor, LinkInfo::needs_access_check, tag);

  switch (bc) {

  case Bytecodes::_invokestatic:

    dest_method =

      LinkResolver::resolve_static_call_or_null(link_info);

    break;

  case Bytecodes::_invokespecial:

    dest_method =

      LinkResolver::resolve_special_call_or_null(link_info);

    break;

  case Bytecodes::_invokeinterface:

    dest_method =

      LinkResolver::linktime_resolve_interface_method_or_null(link_info);

    break;

  case Bytecodes::_invokevirtual:

    dest_method =

      LinkResolver::linktime_resolve_virtual_method_or_null(link_info);

    break;

  default: ShouldNotReachHere();

  }

  return dest_method;

}

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

methodHandle JVMCIEnv::get_method_by_index_impl(const constantPoolHandle& cpool,

                                          int index, Bytecodes::Code bc,

                                          InstanceKlass* accessor) {

  if (bc == Bytecodes::_invokedynamic) {

    ConstantPoolCacheEntry* cpce = cpool->invokedynamic_cp_cache_entry_at(index);

    bool is_resolved = !cpce->is_f1_null();

    if (is_resolved) {

      // Get the invoker Method* from the constant pool.

      // (The appendix argument, if any, will be noted in the method's signature.)

      Method* adapter = cpce->f1_as_method();

      return methodHandle(adapter);

    }

    return NULL;

  }

  int holder_index = cpool->klass_ref_index_at(index);

  bool holder_is_accessible;

  Klass* holder = get_klass_by_index_impl(cpool, holder_index, holder_is_accessible, accessor);

  // Get the method's name and signature.

  Symbol* name_sym = cpool->name_ref_at(index);

  Symbol* sig_sym  = cpool->signature_ref_at(index);

  if (cpool->has_preresolution()

      || ((holder == SystemDictionary::MethodHandle_klass() || holder == SystemDictionary::VarHandle_klass()) &&

          MethodHandles::is_signature_polymorphic_name(holder, name_sym))) {

    // Short-circuit lookups for JSR 292-related call sites.

    // That is, do not rely only on name-based lookups, because they may fail

    // if the names are not resolvable in the boot class loader (7056328).

    switch (bc) {

    case Bytecodes::_invokevirtual:

    case Bytecodes::_invokeinterface:

    case Bytecodes::_invokespecial:

    case Bytecodes::_invokestatic:

      {

        Method* m = ConstantPool::method_at_if_loaded(cpool, index);

        if (m != NULL) {

          return m;

        }

      }

      break;

    default:

      break;

    }

  }

  if (holder_is_accessible) { // Our declared holder is loaded.

    constantTag tag = cpool->tag_ref_at(index);

    methodHandle m = lookup_method(accessor, holder, name_sym, sig_sym, bc, tag);

    if (!m.is_null() &&

        (bc == Bytecodes::_invokestatic

         ?  InstanceKlass::cast(m->method_holder())->is_not_initialized()

         : !InstanceKlass::cast(m->method_holder())->is_loaded())) {

      m = NULL;

    }

    if (!m.is_null()) {

      // We found the method.

      return m;

    }

  }

  // Either the declared holder was not loaded, or the method could

  // not be found.

  return NULL;

}

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

InstanceKlass* JVMCIEnv::get_instance_klass_for_declared_method_holder(Klass* method_holder) {

  // For the case of <array>.clone(), the method holder can be an ArrayKlass*

  // instead of an InstanceKlass*.  For that case simply pretend that the

  // declared holder is Object.clone since that's where the call will bottom out.

  if (method_holder->is_instance_klass()) {

    return InstanceKlass::cast(method_holder);

  } else if (method_holder->is_array_klass()) {

    return SystemDictionary::Object_klass();

  } else {

    ShouldNotReachHere();

  }

  return NULL;

}

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

methodHandle JVMCIEnv::get_method_by_index(const constantPoolHandle& cpool,

                                     int index, Bytecodes::Code bc,

                                     InstanceKlass* accessor) {

  ResourceMark rm;

  return get_method_by_index_impl(cpool, index, bc, accessor);

}

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

// Check for changes to the system dictionary during compilation

// class loads, evolution, breakpoints

JVMCIEnv::CodeInstallResult JVMCIEnv::check_for_system_dictionary_modification(Dependencies* dependencies, Handle compiled_code,

                                                                               JVMCIEnv* env, char** failure_detail) {

  // If JVMTI capabilities were enabled during compile, the compilation is invalidated.

  if (env != NULL) {

    if (!env->_jvmti_can_hotswap_or_post_breakpoint && JvmtiExport::can_hotswap_or_post_breakpoint()) {

      *failure_detail = (char*) "Hotswapping or breakpointing was enabled during compilation";

      return JVMCIEnv::dependencies_failed;

    }

  }

  // Dependencies must be checked when the system dictionary changes

  // or if we don't know whether it has changed (i.e., env == NULL).

  // In debug mode, always check dependencies.

  bool counter_changed = env != NULL && env->_system_dictionary_modification_counter != SystemDictionary::number_of_modifications();

  bool verify_deps = env == NULL || trueInDebug || JavaAssertions::enabled(SystemDictionary::HotSpotInstalledCode_klass()->name()->as_C_string(), true);

  if (!counter_changed && !verify_deps) {

    return JVMCIEnv::ok;

  }

  for (Dependencies::DepStream deps(dependencies); deps.next(); ) {

    Klass* witness = deps.check_dependency();

    if (witness != NULL) {

      // Use a fixed size buffer to prevent the string stream from

      // resizing in the context of an inner resource mark.

      char* buffer = NEW_RESOURCE_ARRAY(char, O_BUFLEN);

      stringStream st(buffer, O_BUFLEN);

      deps.print_dependency(witness, true, &st);

      *failure_detail = st.as_string();

      if (env == NULL || counter_changed || deps.type() == Dependencies::evol_method) {

        return JVMCIEnv::dependencies_failed;

      } else {

        // The dependencies were invalid at the time of installation

        // without any intervening modification of the system

        // dictionary.  That means they were invalidly constructed.

        return JVMCIEnv::dependencies_invalid;

      }

    }

    if (LogCompilation) {

      deps.log_dependency();

    }

  }

  return JVMCIEnv::ok;

}

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

JVMCIEnv::CodeInstallResult JVMCIEnv::register_method(

                                const methodHandle& method,

                                nmethod*& nm,

                                int entry_bci,

                                CodeOffsets* offsets,

                                int orig_pc_offset,

                                CodeBuffer* code_buffer,

                                int frame_words,

                                OopMapSet* oop_map_set,

                                ExceptionHandlerTable* handler_table,

                                AbstractCompiler* compiler,

                                DebugInformationRecorder* debug_info,

                                Dependencies* dependencies,

                                JVMCIEnv* env,

                                int compile_id,

                                bool has_unsafe_access,

                                bool has_wide_vector,

                                Handle installed_code,

                                Handle compiled_code,

                                Handle speculation_log) {

  JVMCI_EXCEPTION_CONTEXT;

  nm = NULL;

  int comp_level = CompLevel_full_optimization;

  char* failure_detail = NULL;

  JVMCIEnv::CodeInstallResult result;

  {

    // To prevent compile queue updates.

    MutexLocker locker(MethodCompileQueue_lock, THREAD);

    // Prevent SystemDictionary::add_to_hierarchy from running

    // and invalidating our dependencies until we install this method.

    MutexLocker ml(Compile_lock);

    // Encode the dependencies now, so we can check them right away.

    dependencies->encode_content_bytes();

    // Check for {class loads, evolution, breakpoints} during compilation

    result = check_for_system_dictionary_modification(dependencies, compiled_code, env, &failure_detail);

    if (result != JVMCIEnv::ok) {

      // While not a true deoptimization, it is a preemptive decompile.

      MethodData* mdp = method()->method_data();

      if (mdp != NULL) {

        mdp->inc_decompile_count();

#ifdef ASSERT

        if (mdp->decompile_count() > (uint)PerMethodRecompilationCutoff) {

          ResourceMark m;

          tty->print_cr("WARN: endless recompilation of %s. Method was set to not compilable.", method()->name_and_sig_as_C_string());

        }

#endif

      }

      // All buffers in the CodeBuffer are allocated in the CodeCache.

      // If the code buffer is created on each compile attempt

      // as in C2, then it must be freed.

      //code_buffer->free_blob();

    } else {