/*

 * Copyright 1999-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

class CompileTask;

// ciEnv

//

// This class is the top level broker for requests from the compiler

// to the VM.

class ciEnv : StackObj {

  CI_PACKAGE_ACCESS_TO

  friend class CompileBroker;

  friend class Dependencies;  // for get_object, during logging

private:

  Arena*           _arena;       // Alias for _ciEnv_arena except in init_shared_objects()

  Arena            _ciEnv_arena;

  int              _system_dictionary_modification_counter;

  ciObjectFactory* _factory;

  OopRecorder*     _oop_recorder;

  DebugInformationRecorder* _debug_info;

  Dependencies*    _dependencies;

  const char*      _failure_reason;

  int              _compilable;

  bool             _break_at_compile;

  int              _num_inlined_bytecodes;

  CompileTask*     _task;           // faster access to CompilerThread::task

  CompileLog*      _log;            // faster access to CompilerThread::log

  void*            _compiler_data;  // compiler-specific stuff, if any

  char* _name_buffer;

  int   _name_buffer_len;

  // Distinguished instances of certain ciObjects..

  static ciObject*              _null_object_instance;

  static ciMethodKlass*         _method_klass_instance;

  static ciSymbolKlass*         _symbol_klass_instance;

  static ciKlassKlass*          _klass_klass_instance;

  static ciInstanceKlassKlass*  _instance_klass_klass_instance;

  static ciTypeArrayKlassKlass* _type_array_klass_klass_instance;

  static ciObjArrayKlassKlass*  _obj_array_klass_klass_instance;

  static ciInstanceKlass* _ArrayStoreException;

  static ciInstanceKlass* _Class;

  static ciInstanceKlass* _ClassCastException;

  static ciInstanceKlass* _Object;

  static ciInstanceKlass* _Throwable;

  static ciInstanceKlass* _Thread;

  static ciInstanceKlass* _OutOfMemoryError;

  static ciInstanceKlass* _String;

  static ciSymbol*        _unloaded_cisymbol;

  static ciInstanceKlass* _unloaded_ciinstance_klass;

  static ciObjArrayKlass* _unloaded_ciobjarrayklass;

  static jobject _ArrayIndexOutOfBoundsException_handle;

  static jobject _ArrayStoreException_handle;

  static jobject _ClassCastException_handle;

  ciInstance* _NullPointerException_instance;

  ciInstance* _ArithmeticException_instance;

  ciInstance* _ArrayIndexOutOfBoundsException_instance;

  ciInstance* _ArrayStoreException_instance;

  ciInstance* _ClassCastException_instance;

  // Look up a klass by name from a particular class loader (the accessor's).

  // If require_local, result must be defined in that class loader, or NULL.

  // If !require_local, a result from remote class loader may be reported,

  // if sufficient class loader constraints exist such that initiating

  // a class loading request from the given loader is bound to return

  // the class defined in the remote loader (or throw an error).

  //

  // Return an unloaded klass if !require_local and no class at all is found.

  //

  // The CI treats a klass as loaded if it is consistently defined in

  // another loader, even if it hasn't yet been loaded in all loaders

  // that could potentially see it via delegation.

  ciKlass* get_klass_by_name(ciKlass* accessing_klass,

                             ciSymbol* klass_name,

                             bool require_local);

  // Constant pool access.

  ciKlass*   get_klass_by_index(ciInstanceKlass* loading_klass,

                                int klass_index,

                                bool& is_accessible);

  ciConstant get_constant_by_index(ciInstanceKlass* loading_klass,

                                   int constant_index);

  bool       is_unresolved_string(ciInstanceKlass* loading_klass,

                                   int constant_index) const;

  bool       is_unresolved_klass(ciInstanceKlass* loading_klass,

                                   int constant_index) const;

  ciField*   get_field_by_index(ciInstanceKlass* loading_klass,

                                int field_index);

  ciMethod*  get_method_by_index(ciInstanceKlass* loading_klass,

                                 int method_index, Bytecodes::Code bc);

  // Implementation methods for loading and constant pool access.

  ciKlass* get_klass_by_name_impl(ciKlass* accessing_klass,

                                  ciSymbol* klass_name,

                                  bool require_local);

  ciKlass*   get_klass_by_index_impl(ciInstanceKlass* loading_klass,

                                     int klass_index,

                                     bool& is_accessible);

  ciConstant get_constant_by_index_impl(ciInstanceKlass* loading_klass,

                                        int constant_index);

  bool       is_unresolved_string_impl (instanceKlass* loading_klass,

                                        int constant_index) const;

  bool       is_unresolved_klass_impl (instanceKlass* loading_klass,

                                        int constant_index) const;

  ciField*   get_field_by_index_impl(ciInstanceKlass* loading_klass,

                                     int field_index);

  ciMethod*  get_method_by_index_impl(ciInstanceKlass* loading_klass,

                                      int method_index, Bytecodes::Code bc);

  // Helper methods

  bool       check_klass_accessibility(ciKlass* accessing_klass,

                                      klassOop resolved_klassOop);

  methodOop  lookup_method(instanceKlass*  accessor,

                           instanceKlass*  holder,

                           symbolOop       name,

                           symbolOop       sig,

                           Bytecodes::Code bc);

  // Get a ciObject from the object factory.  Ensures uniqueness

  // of ciObjects.

  ciObject* get_object(oop o) {

    if (o == NULL) {

      return _null_object_instance;

    } else {

      return _factory->get(o);

    }

  }

  ciMethod* get_method_from_handle(jobject method);

  ciInstance* get_or_create_exception(jobject& handle, symbolHandle name);

  // Get a ciMethod representing either an unfound method or

  // a method with an unloaded holder.  Ensures uniqueness of

  // the result.

  ciMethod* get_unloaded_method(ciInstanceKlass* holder,

                                ciSymbol*        name,

                                ciSymbol*        signature) {

    return _factory->get_unloaded_method(holder, name, signature);

  }

  // Get a ciKlass representing an unloaded klass.

  // Ensures uniqueness of the result.

  ciKlass* get_unloaded_klass(ciKlass* accessing_klass,

                              ciSymbol* name) {

    return _factory->get_unloaded_klass(accessing_klass, name, true);

  }

  // See if we already have an unloaded klass for the given name

  // or return NULL if not.

  ciKlass *check_get_unloaded_klass(ciKlass* accessing_klass, ciSymbol* name) {

    return _factory->get_unloaded_klass(accessing_klass, name, false);

  }

  // Get a ciReturnAddress corresponding to the given bci.

  // Ensures uniqueness of the result.

  ciReturnAddress* get_return_address(int bci) {

    return _factory->get_return_address(bci);

  }

  // Get a ciMethodData representing the methodData for a method

  // with none.

  ciMethodData* get_empty_methodData() {

    return _factory->get_empty_methodData();

  }

  // General utility : get a buffer of some required length.

  // Used in symbol creation.

  char* name_buffer(int req_len);

  // Is this thread currently in the VM state?

  static bool is_in_vm();

  // Helper routine for determining the validity of a compilation

  // with respect to concurrent class loading.

  void check_for_system_dictionary_modification(ciMethod* target);

public:

  enum {

    MethodCompilable,

    MethodCompilable_not_at_tier,

    MethodCompilable_never

  };

  ciEnv(CompileTask* task, int system_dictionary_modification_counter);

  // Used only during initialization of the ci

  ciEnv(Arena* arena);

  ~ciEnv();

  OopRecorder* oop_recorder() { return _oop_recorder; }

  void set_oop_recorder(OopRecorder* r) { _oop_recorder = r; }

  DebugInformationRecorder* debug_info() { return _debug_info; }

  void set_debug_info(DebugInformationRecorder* i) { _debug_info = i; }

  Dependencies* dependencies() { return _dependencies; }

  void set_dependencies(Dependencies* d) { _dependencies = d; }

  // This is true if the compilation is not going to produce code.

  // (It is reasonable to retry failed compilations.)

  bool failing() { return _failure_reason != NULL; }

  // Reason this compilation is failing, such as "too many basic blocks".

  const char* failure_reason() { return _failure_reason; }

  // Return state of appropriate compilability

  int compilable() { return _compilable; }

  bool break_at_compile() { return _break_at_compile; }

  void set_break_at_compile(bool z) { _break_at_compile = z; }

  // The compiler task which has created this env.

  // May be useful to find out compile_id, comp_level, etc.

  CompileTask* task() { return _task; }

  // Handy forwards to the task:

  int comp_level();   // task()->comp_level()

  uint compile_id();  // task()->compile_id()

  // Register the result of a compilation.

  void register_method(ciMethod*                 target,

                       int                       entry_bci,

                       CodeOffsets*              offsets,

                       int                       orig_pc_offset,

                       CodeBuffer*               code_buffer,

                       int                       frame_words,

                       OopMapSet*                oop_map_set,

                       ExceptionHandlerTable*    handler_table,

                       ImplicitExceptionTable*   inc_table,

                       AbstractCompiler*         compiler,

                       int                       comp_level,

                       bool                      has_debug_info = true,

                       bool                      has_unsafe_access = false);

  // Access to certain well known ciObjects.

  ciInstanceKlass* ArrayStoreException_klass() {

    return _ArrayStoreException;

  }

  ciInstanceKlass* Class_klass() {

    return _Class;

  }

  ciInstanceKlass* ClassCastException_klass() {

    return _ClassCastException;

  }

  ciInstanceKlass* Object_klass() {

    return _Object;

  }

  ciInstanceKlass* Throwable_klass() {

    return _Throwable;

  }

  ciInstanceKlass* Thread_klass() {

    return _Thread;

  }

  ciInstanceKlass* OutOfMemoryError_klass() {

    return _OutOfMemoryError;

  }

  ciInstanceKlass* String_klass() {

    return _String;

  }

  ciInstance* NullPointerException_instance() {

    assert(_NullPointerException_instance != NULL, "initialization problem");

    return _NullPointerException_instance;

  }

  ciInstance* ArithmeticException_instance() {

    assert(_ArithmeticException_instance != NULL, "initialization problem");

    return _ArithmeticException_instance;

  }

  // Lazy constructors:

  ciInstance* ArrayIndexOutOfBoundsException_instance();

  ciInstance* ArrayStoreException_instance();

  ciInstance* ClassCastException_instance();

  static ciSymbol* unloaded_cisymbol() {

    return _unloaded_cisymbol;

  }

  static ciObjArrayKlass* unloaded_ciobjarrayklass() {

    return _unloaded_ciobjarrayklass;

  }

  static ciInstanceKlass* unloaded_ciinstance_klass() {

    return _unloaded_ciinstance_klass;

  }

  ciKlass*  find_system_klass(ciSymbol* klass_name);

  // Note:  To find a class from its name string, use ciSymbol::make,

  // but consider adding to vmSymbols.hpp instead.

  // Use this to make a holder for non-perm compile time constants.

  // The resulting array is guaranteed to satisfy "has_encoding".

  ciArray*  make_array(GrowableArray<ciObject*>* objects);

  // converts the ciKlass* representing the holder of a method into a

  // ciInstanceKlass*.  This is needed since the holder of a method in

  // the bytecodes could be an array type.  Basically this converts

  // array types into java/lang/Object and other types stay as they are.

  static ciInstanceKlass* get_instance_klass_for_declared_method_holder(ciKlass* klass);

  // Return the machine-level offset of o, which must be an element of a.

  // This may be used to form constant-loading expressions in lieu of simpler encodings.

  int       array_element_offset_in_bytes(ciArray* a, ciObject* o);

  // Access to the compile-lifetime allocation arena.

  Arena*    arena() { return _arena; }

  // What is the current compilation environment?

  static ciEnv* current() { return CompilerThread::current()->env(); }

  // Overload with current thread argument

  static ciEnv* current(CompilerThread *thread) { return thread->env(); }

  // Per-compiler data.  (Used by C2 to publish the Compile* pointer.)

  void* compiler_data() { return _compiler_data; }

  void set_compiler_data(void* x) { _compiler_data = x; }

  // Notice that a method has been inlined in the current compile;

  // used only for statistics.

  void notice_inlined_method(ciMethod* method);

  // Total number of bytecodes in inlined methods in this compile

  int num_inlined_bytecodes() const;

  // Output stream for logging compilation info.

  CompileLog* log() { return _log; }

  void set_log(CompileLog* log) { _log = log; }

  // Check for changes to the system dictionary during compilation

  bool system_dictionary_modification_counter_changed();

  void record_failure(const char* reason);

  void record_method_not_compilable(const char* reason, bool all_tiers = true);

  void record_out_of_memory_failure();

};