/*

 * Copyright (c) 1997, 2010, 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/javaClasses.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "memory/oopFactory.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.inline.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/methodOop.hpp"

#include "oops/oop.inline.hpp"

#include "oops/symbolOop.hpp"

#include "prims/jvm_misc.hpp"

#include "prims/nativeLookup.hpp"

#include "runtime/arguments.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/signature.hpp"

#ifdef TARGET_OS_FAMILY_linux

# include "os_linux.inline.hpp"

#endif

#ifdef TARGET_OS_FAMILY_solaris

# include "os_solaris.inline.hpp"

#endif

#ifdef TARGET_OS_FAMILY_windows

# include "os_windows.inline.hpp"

#endif

static void mangle_name_on(outputStream* st, symbolOop name, int begin, int end) {

  char* bytes = (char*)name->bytes() + begin;

  char* end_bytes = (char*)name->bytes() + end;

  while (bytes < end_bytes) {

    jchar c;

    bytes = UTF8::next(bytes, &c);

    if (c <= 0x7f && isalnum(c)) {

      st->put((char) c);

    } else {

           if (c == '_') st->print("_1");

      else if (c == '/') st->print("_");

      else if (c == ';') st->print("_2");

      else if (c == '[') st->print("_3");

      else               st->print("_%.5x", c);

    }

  }

}

static void mangle_name_on(outputStream* st, symbolOop name) {

  mangle_name_on(st, name, 0, name->utf8_length());

}

char* NativeLookup::pure_jni_name(methodHandle method) {

  stringStream st;

  // Prefix

  st.print("Java_");

  // Klass name

  mangle_name_on(&st, method->klass_name());

  st.print("_");

  // Method name

  mangle_name_on(&st, method->name());

  return st.as_string();

}

char* NativeLookup::long_jni_name(methodHandle method) {

  // Signature ignore the wrapping parenteses and the trailing return type

  stringStream st;

  symbolOop signature = method->signature();

  st.print("__");

  // find ')'

  int end;

  for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++);

  // skip first '('

  mangle_name_on(&st, signature, 1, end);

  return st.as_string();

}

extern "C" {

  void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls);

  void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls);

  void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass);

}

static address lookup_special_native(char* jni_name) {

  // NB: To ignore the jni prefix and jni postfix strstr is used matching.

  if (!JDK_Version::is_gte_jdk14x_version()) {

    // These functions only exist for compatibility with 1.3.1 and earlier

    // Intercept ObjectOutputStream getPrimitiveFieldValues for faster serialization

    if (strstr(jni_name, "Java_java_io_ObjectOutputStream_getPrimitiveFieldValues") != NULL) {

      return CAST_FROM_FN_PTR(address, JVM_GetPrimitiveFieldValues);

    }

    // Intercept ObjectInputStream setPrimitiveFieldValues for faster serialization

    if (strstr(jni_name, "Java_java_io_ObjectInputStream_setPrimitiveFieldValues") != NULL) {

      return CAST_FROM_FN_PTR(address, JVM_SetPrimitiveFieldValues);

    }

  }

  if (strstr(jni_name, "Java_sun_misc_Unsafe_registerNatives") != NULL) {

    return CAST_FROM_FN_PTR(address, JVM_RegisterUnsafeMethods);

  }

  if (strstr(jni_name, "Java_sun_dyn_MethodHandleNatives_registerNatives") != NULL) {

    return CAST_FROM_FN_PTR(address, JVM_RegisterMethodHandleMethods);

  }

  if (strstr(jni_name, "Java_sun_misc_Perf_registerNatives") != NULL) {

    return CAST_FROM_FN_PTR(address, JVM_RegisterPerfMethods);

  }

  return NULL;

}

address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {

  address entry;

  // Compute complete JNI name for style

  stringStream st;

  if (os_style) os::print_jni_name_prefix_on(&st, args_size);

  st.print_raw(pure_name);

  st.print_raw(long_name);

  if (os_style) os::print_jni_name_suffix_on(&st, args_size);

  char* jni_name = st.as_string();

  // If the loader is null we have a system class, so we attempt a lookup in

  // the native Java library. This takes care of any bootstrapping problems.

  // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find

  // gets found the first time around - otherwise an infinite loop can occure. This is

  // another VM/library dependency

  Handle loader(THREAD,

                instanceKlass::cast(method->method_holder())->class_loader());

  if (loader.is_null()) {

    entry = lookup_special_native(jni_name);

    if (entry == NULL) {

    }

    if (entry != NULL) {

      in_base_library = true;

      return entry;

    }

  }

  // Otherwise call static method findNative in ClassLoader

  KlassHandle   klass (THREAD, SystemDictionary::ClassLoader_klass());

  Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);

  JavaValue result(T_LONG);

  JavaCalls::call_static(&result,

                         klass,

                         vmSymbolHandles::findNative_name(),

                         vmSymbolHandles::classloader_string_long_signature(),

                         // Arguments

                         loader,

                         name_arg,

                         CHECK_NULL);

  entry = (address) (intptr_t) result.get_jlong();

  if (entry == NULL) {

    // findNative didn't find it, if there are any agent libraries look in them

    AgentLibrary* agent;

    for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {

      if (entry != NULL) {

        return entry;

      }

    }

  }

  return entry;

}

// Check all the formats of native implementation name to see if there is one

// for the specified method.

address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) {

  address entry = NULL;

  in_base_library = false;

  // Compute pure name

  char* pure_name = pure_jni_name(method);

  // Compute argument size

  int args_size = 1                             // JNIEnv

                + (method->is_static() ? 1 : 0) // class for static methods

                + method->size_of_parameters(); // actual parameters

  // 1) Try JNI short style

  entry = lookup_style(method, pure_name, "",        args_size, true,  in_base_library, CHECK_NULL);

  if (entry != NULL) return entry;

  // Compute long name

  char* long_name = long_jni_name(method);

  // 2) Try JNI long style

  entry = lookup_style(method, pure_name, long_name, args_size, true,  in_base_library, CHECK_NULL);

  if (entry != NULL) return entry;

  // 3) Try JNI short style without os prefix/suffix

  entry = lookup_style(method, pure_name, "",        args_size, false, in_base_library, CHECK_NULL);

  if (entry != NULL) return entry;

  // 4) Try JNI long style without os prefix/suffix

  entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL);

  return entry; // NULL indicates not found

}

// Check if there are any JVM TI prefixes which have been applied to the native method name.

// If any are found, remove them before attemping the look up of the

// native implementation again.

// See SetNativeMethodPrefix in the JVM TI Spec for more details.

address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) {

  ResourceMark rm(THREAD);

  int prefix_count;

  char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);

  char* in_name = method->name()->as_C_string();

  char* wrapper_name = in_name;

  // last applied prefix will be first -- go backwards

  for (int i = prefix_count-1; i >= 0; i--) {

    char* prefix = prefixes[i];

    size_t prefix_len = strlen(prefix);

    if (strncmp(prefix, wrapper_name, prefix_len) == 0) {

      // has this prefix remove it

      wrapper_name += prefix_len;

    }

  }

  if (wrapper_name != in_name) {

    // we have a name for a wrapping method

    int wrapper_name_len = (int)strlen(wrapper_name);

    symbolHandle wrapper_symbol(THREAD, SymbolTable::probe(wrapper_name, wrapper_name_len));

    if (!wrapper_symbol.is_null()) {

      KlassHandle kh(method->method_holder());

      methodOop wrapper_method = Klass::cast(kh())->lookup_method(wrapper_symbol(),

                                                                  method->signature());

      if (wrapper_method != NULL && !wrapper_method->is_native()) {

        // we found a wrapper method, use its native entry

        method->set_is_prefixed_native();

        return lookup_entry(wrapper_method, in_base_library, THREAD);

      }

    }

  }

  return NULL;

}

address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) {

  address entry = NULL;

  ResourceMark rm(THREAD);

  entry = lookup_entry(method, in_base_library, THREAD);

  if (entry != NULL) return entry;

  // standard native method resolution has failed.  Check if there are any

  // JVM TI prefixes which have been applied to the native method name.

  entry = lookup_entry_prefixed(method, in_base_library, THREAD);

  if (entry != NULL) return entry;

  // Native function not found, throw UnsatisfiedLinkError

  THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(),

              method->name_and_sig_as_C_string());

}

address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {

  if (!method->has_native_function()) {

    address entry = lookup_base(method, in_base_library, CHECK_NULL);

    method->set_native_function(entry,

      methodOopDesc::native_bind_event_is_interesting);

    // -verbose:jni printing

    if (PrintJNIResolving) {

      ResourceMark rm(THREAD);

      tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",

        Klass::cast(method->method_holder())->external_name(),

        method->name()->as_C_string());

    }

  }

  return method->native_function();

}

address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) {

  EXCEPTION_MARK;

  bool in_base_library = true;  // SharedRuntime inits some math methods.

  symbolHandle c_name = oopFactory::new_symbol_handle(class_name,  CATCH);

  symbolHandle m_name = oopFactory::new_symbol_handle(method_name, CATCH);

  symbolHandle s_name = oopFactory::new_symbol_handle(signature,   CATCH);

  // Find the class

  klassOop k = SystemDictionary::resolve_or_fail(c_name, true, CATCH);

  instanceKlassHandle klass (THREAD, k);

  // Find method and invoke standard lookup

  methodHandle method (THREAD,

                       klass->uncached_lookup_method(m_name(), s_name()));

  address result = lookup(method, in_base_library, CATCH);

  assert(in_base_library, "must be in basic library");

  guarantee(result != NULL, "must be non NULL");

  return result;

}