/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "class_linker.h"
#include "dex_verifier.h"
#include "object.h"
#include "object_utils.h"
#include "runtime_support.h"
#include "runtime_support_llvm.h"
#include "shadow_frame.h"
#include "thread.h"
#include "thread_list.h"

#include <algorithm>
#include <stdint.h>

namespace art {

//----------------------------------------------------------------------------
// Thread
//----------------------------------------------------------------------------

Thread* art_get_current_thread_from_code() {
  return Thread::Current();
}

void art_set_current_thread_from_code(void* thread_object_addr) {
  // TODO: LLVM IR generating something like "r9 = thread_object_addr"
  // UNIMPLEMENTED(WARNING);
}

void art_lock_object_from_code(Object* obj) {
  Thread* thread = Thread::Current();
  DCHECK(obj != NULL);        // Assumed to have been checked before entry
  obj->MonitorEnter(thread);  // May block
  DCHECK(thread->HoldsLock(obj));
  // Only possible exception is NPE and is handled before entry
  DCHECK(!thread->IsExceptionPending());
}

void art_unlock_object_from_code(Object* obj) {
  Thread* thread = Thread::Current();
  DCHECK(obj != NULL);  // Assumed to have been checked before entry
  // MonitorExit may throw exception
  obj->MonitorExit(thread);
}

void art_test_suspend_from_code() {
  Thread* thread = Thread::Current();
  Runtime::Current()->GetThreadList()->FullSuspendCheck(thread);
}

void art_push_shadow_frame_from_code(void* new_shadow_frame) {
  Thread* thread = Thread::Current();
  thread->PushShadowFrame(static_cast<ShadowFrame*>(new_shadow_frame));
}

void art_pop_shadow_frame_from_code() {
  Thread* thread = Thread::Current();
  thread->PopShadowFrame();
}


//----------------------------------------------------------------------------
// Exception
//----------------------------------------------------------------------------

bool art_is_exception_pending_from_code() {
  return Thread::Current()->IsExceptionPending();
}

void art_throw_div_zero_from_code() {
  Thread* thread = Thread::Current();
  thread->ThrowNewException("Ljava/lang/ArithmeticException;",
                            "divide by zero");
}

void art_throw_array_bounds_from_code(int32_t length, int32_t index) {
  Thread* thread = Thread::Current();
  thread->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
                             "length=%d; index=%d", length, index);
}

void art_throw_no_such_method_from_code(int32_t method_idx) {
  Thread* thread = Thread::Current();
  // We need the calling method as context for the method_idx
  Frame frame = thread->GetTopOfStack();
  frame.Next();
  Method* method = frame.GetMethod();
  thread->ThrowNewException("Ljava/lang/NoSuchMethodError;",
                            MethodNameFromIndex(method,
                                                method_idx,
                                                verifier::VERIFY_ERROR_REF_METHOD,
                                                false).c_str());
}

void art_throw_null_pointer_exception_from_code() {
  Thread* thread = Thread::Current();
  thread->ThrowNewException("Ljava/lang/NullPointerException;", NULL);
}

void art_throw_stack_overflow_from_code() {
  Thread* thread = Thread::Current();
  if (Runtime::Current()->IsMethodTracingActive()) {
    TraceMethodUnwindFromCode(thread);
  }
  thread->SetStackEndForStackOverflow();  // Allow space on the stack for constructor to execute
  thread->ThrowNewExceptionF("Ljava/lang/StackOverflowError;",
      "stack size %zdkb; default stack size: %zdkb",
      thread->GetStackSize() / KB,
      Runtime::Current()->GetDefaultStackSize() / KB);
  thread->ResetDefaultStackEnd();  // Return to default stack size
}

void art_throw_exception_from_code(Object* exception) {
  Thread* thread = Thread::Current();
  if (exception == NULL) {
    thread->ThrowNewException("Ljava/lang/NullPointerException;", "throw with null exception");
  } else {
    thread->SetException(static_cast<Throwable*>(exception));
  }
}

int32_t art_find_catch_block_from_code(Method* current_method, int32_t dex_pc) {
  Thread* thread = Thread::Current();
  Class* exception_type = thread->GetException()->GetClass();
  MethodHelper mh(current_method);
  const DexFile::CodeItem* code_item = mh.GetCodeItem();
  int iter_index = 0;
  // Iterate over the catch handlers associated with dex_pc
  for (CatchHandlerIterator it(*code_item, dex_pc); it.HasNext(); it.Next()) {
    uint16_t iter_type_idx = it.GetHandlerTypeIndex();
    // Catch all case
    if (iter_type_idx == DexFile::kDexNoIndex16) {
      return iter_index;
    }
    // Does this catch exception type apply?
    Class* iter_exception_type = mh.GetDexCacheResolvedType(iter_type_idx);
    if (iter_exception_type == NULL) {
      // The verifier should take care of resolving all exception classes early
      LOG(WARNING) << "Unresolved exception class when finding catch block: "
          << mh.GetTypeDescriptorFromTypeIdx(iter_type_idx);
    } else if (iter_exception_type->IsAssignableFrom(exception_type)) {
      return iter_index;
    }
    ++iter_index;
  }
  // Handler not found
  return -1;
}


//----------------------------------------------------------------------------
// Object Space
//----------------------------------------------------------------------------

Object* art_alloc_object_from_code(uint32_t type_idx, Method* referrer) {
  return AllocObjectFromCode(type_idx, referrer, Thread::Current(), false);
}

Object* art_alloc_object_from_code_with_access_check(uint32_t type_idx, Method* referrer) {
  return AllocObjectFromCode(type_idx, referrer, Thread::Current(), true);
}

Object* art_alloc_array_from_code(uint32_t type_idx, Method* referrer, uint32_t length) {
  return AllocArrayFromCode(type_idx, referrer, length, Thread::Current(), false);
}

Object* art_alloc_array_from_code_with_access_check(uint32_t type_idx,
                                                    Method* referrer,
                                                    uint32_t length) {
  return AllocArrayFromCode(type_idx, referrer, length, Thread::Current(), true);
}

Object* art_check_and_alloc_array_from_code(uint32_t type_idx,
                                            Method* referrer,
                                            uint32_t length) {
  return CheckAndAllocArrayFromCode(type_idx, referrer, length, Thread::Current(), false);
}

Object* art_check_and_alloc_array_from_code_with_access_check(uint32_t type_idx,
                                                              Method* referrer,
                                                              uint32_t length) {
  return CheckAndAllocArrayFromCode(type_idx, referrer, length, Thread::Current(), true);
}

static Method* FindMethodHelper(uint32_t method_idx, Object* this_object, Method* caller_method,
                                bool access_check, InvokeType type) {
  Method* method = FindMethodFast(method_idx, this_object, caller_method, access_check, type);
  if (UNLIKELY(method == NULL)) {
    method = FindMethodFromCode(method_idx, this_object, caller_method,
                                Thread::Current(), access_check, type);
    if (UNLIKELY(method == NULL)) {
      CHECK(Thread::Current()->IsExceptionPending());
      return 0;  // failure
    }
  }
  DCHECK(!Thread::Current()->IsExceptionPending());
  return method;
}

Object* art_find_interface_method_from_code(uint32_t method_idx,
                                            Object* this_object,
                                            Method* referrer) {
  return FindMethodHelper(method_idx, this_object, referrer, true, kInterface);
}

Object* art_find_virtual_method_from_code(uint32_t method_idx,
                                          Object* this_object,
                                          Method* referrer) {
  return FindMethodHelper(method_idx, this_object, referrer, true, kVirtual);
}

Object* art_find_super_method_from_code(uint32_t method_idx,
                                        Object* this_object,
                                        Method* referrer) {
  return FindMethodHelper(method_idx, this_object, referrer, true, kSuper);
}

Object* art_initialize_static_storage_from_code(uint32_t type_idx, Method* referrer) {
  return ResolveVerifyAndClinit(type_idx, referrer, Thread::Current(), true, true);
}

Object* art_initialize_type_from_code(uint32_t type_idx, Method* referrer) {
  return ResolveVerifyAndClinit(type_idx, referrer, Thread::Current(), false, false);
}

Object* art_initialize_type_and_verify_access_from_code(uint32_t type_idx, Method* referrer) {
  // Called when caller isn't guaranteed to have access to a type and the dex cache may be
  // unpopulated
  return ResolveVerifyAndClinit(type_idx, referrer, Thread::Current(), false, true);
}

Object* art_resolve_string_from_code(Method* referrer, uint32_t string_idx) {
  return ResolveStringFromCode(referrer, string_idx);
}

int32_t art_set32_static_from_code(uint32_t field_idx, Method* referrer, int32_t new_value) {
  Field* field = FindFieldFast(field_idx, referrer, true, true, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    field->Set32(NULL, new_value);
    return 0;
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            true, true, true, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    field->Set32(NULL, new_value);
    return 0;
  }
  return -1;
}

int32_t art_set64_static_from_code(uint32_t field_idx, Method* referrer, int64_t new_value) {
  Field* field = FindFieldFast(field_idx, referrer, true, true, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    field->Set64(NULL, new_value);
    return 0;
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            true, true, true, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    field->Set64(NULL, new_value);
    return 0;
  }
  return -1;
}

int32_t art_set_obj_static_from_code(uint32_t field_idx, Method* referrer, Object* new_value) {
  Field* field = FindFieldFast(field_idx, referrer, false, true, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    field->SetObj(NULL, new_value);
    return 0;
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            true, false, true, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    field->SetObj(NULL, new_value);
    return 0;
  }
  return -1;
}

int32_t art_get32_static_from_code(uint32_t field_idx, Method* referrer) {
  Field* field = FindFieldFast(field_idx, referrer, true, false, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    return field->Get32(NULL);
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            true, true, false, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    return field->Get32(NULL);
  }
  return 0;
}

int64_t art_get64_static_from_code(uint32_t field_idx, Method* referrer) {
  Field* field = FindFieldFast(field_idx, referrer, true, false, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    return field->Get64(NULL);
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            true, true, false, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    return field->Get64(NULL);
  }
  return 0;
}

Object* art_get_obj_static_from_code(uint32_t field_idx, Method* referrer) {
  Field* field = FindFieldFast(field_idx, referrer, false, false, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    return field->GetObj(NULL);
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            true, false, false, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    return field->GetObj(NULL);
  }
  return 0;
}

int32_t art_set32_instance_from_code(uint32_t field_idx, Method* referrer,
                                     Object* obj, uint32_t new_value) {
  Field* field = FindFieldFast(field_idx, referrer, true, true, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    field->Set32(obj, new_value);
    return 0;
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            false, true, true, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    field->Set32(obj, new_value);
    return 0;
  }
  return -1;
}

int32_t art_set64_instance_from_code(uint32_t field_idx, Method* referrer,
                                     Object* obj, int64_t new_value) {
  Field* field = FindFieldFast(field_idx, referrer, true, true, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    field->Set64(obj, new_value);
    return 0;
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            false, true, true, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    field->Set64(obj, new_value);
    return 0;
  }
  return -1;
}

int32_t art_set_obj_instance_from_code(uint32_t field_idx, Method* referrer,
                                       Object* obj, Object* new_value) {
  Field* field = FindFieldFast(field_idx, referrer, false, true, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    field->SetObj(obj, new_value);
    return 0;
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            false, false, true, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    field->SetObj(obj, new_value);
    return 0;
  }
  return -1;
}

int32_t art_get32_instance_from_code(uint32_t field_idx, Method* referrer, Object* obj) {
  Field* field = FindFieldFast(field_idx, referrer, true, false, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    return field->Get32(obj);
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            false, true, false, sizeof(uint32_t));
  if (LIKELY(field != NULL)) {
    return field->Get32(obj);
  }
  return 0;
}

int64_t art_get64_instance_from_code(uint32_t field_idx, Method* referrer, Object* obj) {
  Field* field = FindFieldFast(field_idx, referrer, true, false, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    return field->Get64(obj);
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            false, true, false, sizeof(uint64_t));
  if (LIKELY(field != NULL)) {
    return field->Get64(obj);
  }
  return 0;
}

Object* art_get_obj_instance_from_code(uint32_t field_idx, Method* referrer, Object* obj) {
  Field* field = FindFieldFast(field_idx, referrer, false, false, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    return field->GetObj(obj);
  }
  field = FindFieldFromCode(field_idx, referrer, Thread::Current(),
                            false, false, false, sizeof(Object*));
  if (LIKELY(field != NULL)) {
    return field->GetObj(obj);
  }
  return 0;
}

Object* art_decode_jobject_in_thread(Thread* thread, jobject obj) {
  if (thread->IsExceptionPending()) {
    return NULL;
  }
  return thread->DecodeJObject(obj);
}

//----------------------------------------------------------------------------
// Type checking, in the nature of casting
//----------------------------------------------------------------------------

int32_t art_is_assignable_from_code(const Class* dest_type, const Class* src_type) {
  DCHECK(dest_type != NULL);
  DCHECK(src_type != NULL);
  return dest_type->IsAssignableFrom(src_type) ? 1 : 0;
}

void art_check_cast_from_code(const Class* dest_type, const Class* src_type) {
  DCHECK(dest_type->IsClass()) << PrettyClass(dest_type);
  DCHECK(src_type->IsClass()) << PrettyClass(src_type);
  if (UNLIKELY(!dest_type->IsAssignableFrom(src_type))) {
    Thread::Current()->ThrowNewExceptionF("Ljava/lang/ClassCastException;",
        "%s cannot be cast to %s",
        PrettyDescriptor(dest_type).c_str(),
        PrettyDescriptor(src_type).c_str());
  }
}

void art_check_put_array_element_from_code(const Object* element, const Object* array) {
  if (element == NULL) {
    return;
  }
  DCHECK(array != NULL);
  Class* array_class = array->GetClass();
  DCHECK(array_class != NULL);
  Class* component_type = array_class->GetComponentType();
  Class* element_class = element->GetClass();
  if (UNLIKELY(!component_type->IsAssignableFrom(element_class))) {
    Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
        "%s cannot be stored in an array of type %s",
        PrettyDescriptor(element_class).c_str(),
        PrettyDescriptor(array_class).c_str());
  }
  return;
}

//----------------------------------------------------------------------------
// Runtime Support Function Lookup Callback
//----------------------------------------------------------------------------

class CStringComparator {
 public:
  bool operator()(const char* lhs, const char* rhs) const {
    return (strcmp(lhs, rhs) < 0);
  }
};

#define EXTERNAL_LINKAGE(NAME) \
extern "C" void NAME(...);

#include "compiler_runtime_func_list.h"
COMPILER_RUNTIME_FUNC_LIST(EXTERNAL_LINKAGE)
#undef COMPILER_RUNTIME_FUNC_LIST
#undef EXTERNAL_LINKAGE

static void* art_find_compiler_runtime_func(char const* name) {
  static const char* const names[] = {
#define DEFINE_ENTRY(NAME) #NAME ,
#include "compiler_runtime_func_list.h"
    COMPILER_RUNTIME_FUNC_LIST(DEFINE_ENTRY)
#undef COMPILER_RUNTIME_FUNC_LIST
#undef DEFINE_ENTRY
  };

  static void* const funcs[] = {
#define DEFINE_ENTRY(NAME) reinterpret_cast<void*>(NAME) ,
#include "compiler_runtime_func_list.h"
    COMPILER_RUNTIME_FUNC_LIST(DEFINE_ENTRY)
#undef COMPILER_RUNTIME_FUNC_LIST
#undef DEFINE_ENTRY
  };

  static const size_t num_entries = sizeof(names) / sizeof(const char* const);

  const char* const* const names_begin = names;
  const char* const* const names_end = names + num_entries;

  const char* const* name_lbound_ptr =
      std::lower_bound(names_begin, names_end, name, CStringComparator());

  if (name_lbound_ptr < names_end && strcmp(*name_lbound_ptr, name) == 0) {
    return funcs[name_lbound_ptr - names_begin];
  } else {
    return NULL;
  }
}

void* art_find_runtime_support_func(void* context, char const* name) {
  struct func_entry_t {
    char const* name;
    size_t name_len;
    void* addr;
  };

  static struct func_entry_t const tab[] = {
#define DEFINE_ENTRY(ID, NAME) \
    { #NAME, sizeof(#NAME) - 1, reinterpret_cast<void*>(NAME) },

#include "runtime_support_func_list.h"
    RUNTIME_SUPPORT_FUNC_LIST(DEFINE_ENTRY)
#undef RUNTIME_SUPPORT_FUNC_LIST
#undef DEFINE_ENTRY
  };

  static size_t const tab_size = sizeof(tab) / sizeof(struct func_entry_t);

  // Search the compiler runtime (such as __divdi3)
  void* result = art_find_compiler_runtime_func(name);
  if (result != NULL) {
    return result;
  }

  // Note: Since our table is small, we are using trivial O(n) searching
  // function.  For bigger table, it will be better to use binary
  // search or hash function.
  size_t i;
  size_t name_len = strlen(name);
  for (i = 0; i < tab_size; ++i) {
    if (name_len == tab[i].name_len && strcmp(name, tab[i].name) == 0) {
      return tab[i].addr;
    }
  }

  LOG(FATAL) << "Error: Can't find symbol " << name;
  return 0;
}

}  // namespace art