/*

 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2016, 2017, SAP SE. 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 "asm/macroAssembler.inline.hpp"

#include "classfile/javaClasses.inline.hpp"

#include "interpreter/interpreter.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/resourceArea.hpp"

#include "prims/methodHandles.hpp"

#ifdef PRODUCT

#define __ _masm->

#define BLOCK_COMMENT(str) /* nothing */

#else

#define __ (Verbose ? (_masm->block_comment(FILE_AND_LINE),_masm):_masm)->

#define BLOCK_COMMENT(str) __ block_comment(str)

#endif

#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")

// Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.

static RegisterOrConstant constant(int value) {

  return RegisterOrConstant(value);

}

void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg,

                                          Register temp_reg, Register temp2_reg) {

  if (VerifyMethodHandles) {

    verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class),

                 temp_reg, temp2_reg, "MH argument is a Class");

  }

  __ z_lg(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));

}

#ifdef ASSERT

static int check_nonzero(const char* xname, int x) {

  assert(x != 0, "%s should be nonzero", xname);

  return x;

}

#define NONZERO(x) check_nonzero(#x, x)

#else

#define NONZERO(x) (x)

#endif

#ifdef ASSERT

void MethodHandles::verify_klass(MacroAssembler* _masm,

                                 Register obj_reg, SystemDictionary::WKID klass_id,

                                 Register temp_reg, Register temp2_reg,

                                 const char* error_message) {

  InstanceKlass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);

  Klass* klass = SystemDictionary::well_known_klass(klass_id);

  assert(temp_reg != Z_R0 && // Is used as base register!

         temp_reg != noreg && temp2_reg != noreg, "need valid registers!");

  NearLabel L_ok, L_bad;

  BLOCK_COMMENT("verify_klass {");

  __ verify_oop(obj_reg);

  __ compareU64_and_branch(obj_reg, (intptr_t)0L, Assembler::bcondEqual, L_bad);

  __ load_klass(temp_reg, obj_reg);

  // klass_addr is a klass in allstatic SystemDictionaryHandles. Can't get GCed.

  __ load_const_optimized(temp2_reg, (address)klass_addr);

  __ z_lg(temp2_reg, Address(temp2_reg));

  __ compareU64_and_branch(temp_reg, temp2_reg, Assembler::bcondEqual, L_ok);

  intptr_t super_check_offset = klass->super_check_offset();

  __ z_lg(temp_reg, Address(temp_reg, super_check_offset));

  __ compareU64_and_branch(temp_reg, temp2_reg, Assembler::bcondEqual, L_ok);

  __ BIND(L_bad);

  __ stop(error_message);

  __ BIND(L_ok);

  BLOCK_COMMENT("} verify_klass");

}

void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind,

                                    Register member_reg, Register temp  ) {

  NearLabel L;

  BLOCK_COMMENT("verify_ref_kind {");

  __ z_llgf(temp,

            Address(member_reg,

                    NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())));

  __ z_srl(temp,  java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);

  __ z_nilf(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);

  __ compare32_and_branch(temp, constant(ref_kind), Assembler::bcondEqual, L);

  {

    char *buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);

    jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);

    if (ref_kind == JVM_REF_invokeVirtual || ref_kind == JVM_REF_invokeSpecial) {

      // Could do this for all ref_kinds, but would explode assembly code size.

      trace_method_handle(_masm, buf);

    }

    __ stop(buf);

  }

  BLOCK_COMMENT("} verify_ref_kind");

  __ bind(L);

}

#endif // ASSERT

void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target,

                                            Register temp, bool for_compiler_entry) {

  assert(method == Z_method, "interpreter calling convention");

  __ verify_method_ptr(method);

  assert(target != method, "don 't you kill the method reg!");

  Label L_no_such_method;

  if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {

    // JVMTI events, such as single-stepping, are implemented partly

    // by avoiding running compiled code in threads for which the

    // event is enabled. Check here for interp_only_mode if these

    // events CAN be enabled.

    __ verify_thread();

    Label run_compiled_code;

    __ load_and_test_int(temp, Address(Z_thread, JavaThread::interp_only_mode_offset()));

    __ z_bre(run_compiled_code);

    // Null method test is replicated below in compiled case,

    // it might be able to address across the verify_thread().

    __ z_ltgr(temp, method);

    __ z_bre(L_no_such_method);

    __ z_lg(target, Address(method, Method::interpreter_entry_offset()));

    __ z_br(target);

    __ bind(run_compiled_code);

  }

  // Compiled case, either static or fall-through from runtime conditional.

  __ z_ltgr(temp, method);

  __ z_bre(L_no_such_method);

  ByteSize offset = for_compiler_entry ?

                       Method::from_compiled_offset() : Method::from_interpreted_offset();

  Address method_from(method, offset);

  __ z_lg(target, method_from);

  __ z_br(target);

  __ bind(L_no_such_method);

  assert(StubRoutines::throw_AbstractMethodError_entry() != NULL, "not yet generated!");

  __ load_const_optimized(target, StubRoutines::throw_AbstractMethodError_entry());

  __ z_br(target);

}

void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,

                                        Register recv, Register method_temp,

                                        Register temp2, Register temp3,

                                        bool for_compiler_entry) {

  // This is the initial entry point of a lazy method handle.

  // After type checking, it picks up the invoker from the LambdaForm.

  assert_different_registers(recv, method_temp, temp2, temp3);

  assert(method_temp == Z_method, "required register for loading method");

  BLOCK_COMMENT("jump_to_lambda_form {");

  // Load the invoker, as MH -> MH.form -> LF.vmentry

  __ verify_oop(recv);

  __ load_heap_oop(method_temp,

                     Address(recv,

                             NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())));

  __ verify_oop(method_temp);

  __ load_heap_oop(method_temp,

                     Address(method_temp,

                             NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())));

  __ verify_oop(method_temp);

  __ load_heap_oop(method_temp,

          Address(method_temp,

                  NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes())));

  __ verify_oop(method_temp);

  __ z_lg(method_temp,

          Address(method_temp,

                  NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes())));

  if (VerifyMethodHandles && !for_compiler_entry) {

    // Make sure recv is already on stack.

    NearLabel L;

    Address paramSize(temp2, ConstMethod::size_of_parameters_offset());

    __ z_lg(temp2, Address(method_temp, Method::const_offset()));

    __ load_sized_value(temp2, paramSize, sizeof(u2), /*is_signed*/ false);

    // if (temp2 != recv) stop

    __ z_lg(temp2, __ argument_address(temp2, temp2, 0));

    __ compare64_and_branch(temp2, recv, Assembler::bcondEqual, L);

    __ stop("receiver not on stack");

    __ BIND(L);

  }

  jump_from_method_handle(_masm, method_temp, temp2, Z_R0, for_compiler_entry);

  BLOCK_COMMENT("} jump_to_lambda_form");

}

// code generation

address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,

                                                                vmIntrinsics::ID iid) {

  const bool not_for_compiler_entry = false;  // This is the interpreter entry.

  assert(is_signature_polymorphic(iid), "expected invoke iid");

  if (iid == vmIntrinsics::_invokeGeneric || iid == vmIntrinsics::_compiledLambdaForm) {

    // Perhaps surprisingly, the symbolic references visible to Java

    // are not directly used. They are linked to Java-generated

    // adapters via MethodHandleNatives.linkMethod. They all allow an

    // appendix argument.

    __ should_not_reach_here();           // Empty stubs make SG sick.

    return NULL;

  }

  // Z_R10: sender SP (must preserve; see prepare_to_jump_from_interprted)

  // Z_method: method

  // Z_ARG1 (Gargs): incoming argument list (must preserve)

  Register Z_R4_param_size = Z_R4;   // size of parameters

  address code_start = __ pc();

  // Here is where control starts out:

  __ align(CodeEntryAlignment);

  address entry_point = __ pc();

  if (VerifyMethodHandles) {

    Label L;

    BLOCK_COMMENT("verify_intrinsic_id {");

    // Supplement to 8139891: _intrinsic_id exceeded 1-byte size limit.

    if (Method::intrinsic_id_size_in_bytes() == 1) {

      __ z_cli(Address(Z_method, Method::intrinsic_id_offset_in_bytes()), (int)iid);

    } else {

      assert(Method::intrinsic_id_size_in_bytes() == 2, "size error: check Method::_intrinsic_id");

      __ z_lh(Z_R0_scratch, Address(Z_method, Method::intrinsic_id_offset_in_bytes()));

      __ z_chi(Z_R0_scratch, (int)iid);

    }

    __ z_bre(L);

    if (iid == vmIntrinsics::_linkToVirtual || iid == vmIntrinsics::_linkToSpecial) {

      // Could do this for all kinds, but would explode assembly code size.

      trace_method_handle(_masm, "bad Method::intrinsic_id");

    }

    __ stop("bad Method::intrinsic_id");

    __ bind(L);

    BLOCK_COMMENT("} verify_intrinsic_id");

  }

  // First task: Find out how big the argument list is.

  Address Z_R4_first_arg_addr;

  int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);

  assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic,

         "must be _invokeBasic or a linkTo intrinsic");

  if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {

     Address paramSize(Z_R1_scratch, ConstMethod::size_of_parameters_offset());

    __ z_lg(Z_R1_scratch, Address(Z_method, Method::const_offset()));

    __ load_sized_value(Z_R4_param_size, paramSize, sizeof(u2), /*is_signed*/ false);

    Z_R4_first_arg_addr = __ argument_address(Z_R4_param_size, Z_R4_param_size, 0);

  } else {

    DEBUG_ONLY(Z_R4_param_size = noreg);

  }

  Register Z_mh = noreg;

  if (!is_signature_polymorphic_static(iid)) {

    Z_mh = Z_ARG4;

    __ z_lg(Z_mh, Z_R4_first_arg_addr);

    DEBUG_ONLY(Z_R4_param_size = noreg);

  }

  // Z_R4_first_arg_addr is live!

  trace_method_handle_interpreter_entry(_masm, iid);

  if (iid == vmIntrinsics::_invokeBasic) {

    __ pc(); // just for the block comment

    generate_method_handle_dispatch(_masm, iid, Z_mh, noreg, not_for_compiler_entry);

  } else {

    // Adjust argument list by popping the trailing MemberName argument.

    Register Z_recv = noreg;

    if (MethodHandles::ref_kind_has_receiver(ref_kind)) {

      // Load the receiver (not the MH; the actual MemberName's receiver)

      // up from the interpreter stack.

      __ z_lg(Z_recv = Z_R5, Z_R4_first_arg_addr);

      DEBUG_ONLY(Z_R4_param_size = noreg);

    }

    Register Z_member = Z_method;  // MemberName ptr; incoming method ptr is dead now

    __ z_lg(Z_member, __ argument_address(constant(1)));

    __ add2reg(Z_esp, Interpreter::stackElementSize);

    generate_method_handle_dispatch(_masm, iid, Z_recv, Z_member, not_for_compiler_entry);

  }

  return entry_point;

}

void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,

                                                    vmIntrinsics::ID iid,

                                                    Register receiver_reg,

                                                    Register member_reg,

                                                    bool for_compiler_entry) {

  assert(is_signature_polymorphic(iid), "expected invoke iid");

  Register temp1 = for_compiler_entry ? Z_R10 : Z_R6;

  Register temp2 = Z_R12;

  Register temp3 = Z_R11;

  Register temp4 = Z_R13;

  if (for_compiler_entry) {

    assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : Z_ARG1),

           "only valid assignment");

  }

  if (receiver_reg != noreg) {

    assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);

  }

  if (member_reg != noreg) {

    assert_different_registers(temp1, temp2, temp3, temp4, member_reg);

  }

  if (!for_compiler_entry) {  // Don't trash last SP.

    assert_different_registers(temp1, temp2, temp3, temp4, Z_R10);

  }

  if (iid == vmIntrinsics::_invokeBasic) {

    __ pc(); // Just for the block comment.

    // Indirect through MH.form.vmentry.vmtarget.

    jump_to_lambda_form(_masm, receiver_reg, Z_method, Z_R1, temp3, for_compiler_entry);

    return;

  }

  // The method is a member invoker used by direct method handles.

  if (VerifyMethodHandles) {

    // Make sure the trailing argument really is a MemberName (caller responsibility).

    verify_klass(_masm, member_reg,

                 SystemDictionary::WK_KLASS_ENUM_NAME(MemberName_klass),

                 temp1, temp2,

                 "MemberName required for invokeVirtual etc.");

  }

  Address  member_clazz(   member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));

  Address  member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));

  Address  member_vmtarget(member_reg, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes()));

  Address  vmtarget_method(Z_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes()));

  Register temp1_recv_klass = temp1;

  if (iid != vmIntrinsics::_linkToStatic) {

    __ verify_oop(receiver_reg);

    if (iid == vmIntrinsics::_linkToSpecial) {

      // Don't actually load the klass; just null-check the receiver.

      __ null_check(receiver_reg);

    } else {

      // Load receiver klass itself.

      __ null_check(receiver_reg, Z_R0, oopDesc::klass_offset_in_bytes());

      __ load_klass(temp1_recv_klass, receiver_reg);

      __ verify_klass_ptr(temp1_recv_klass);

    }

    BLOCK_COMMENT("check_receiver {");

    // The receiver for the MemberName must be in receiver_reg.

    // Check the receiver against the MemberName.clazz.

    if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {

      // Did not load it above...

      __ load_klass(temp1_recv_klass, receiver_reg);

      __ verify_klass_ptr(temp1_recv_klass);

    }

    if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {

      NearLabel L_ok;

      Register temp2_defc = temp2;

      __ load_heap_oop(temp2_defc, member_clazz);

      load_klass_from_Class(_masm, temp2_defc, temp3, temp4);

      __ verify_klass_ptr(temp2_defc);

      __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);

      // If we get here, the type check failed!

      __ stop("receiver class disagrees with MemberName.clazz");

      __ bind(L_ok);

    }

    BLOCK_COMMENT("} check_receiver");

  }

  if (iid == vmIntrinsics::_linkToSpecial || iid == vmIntrinsics::_linkToStatic) {

    DEBUG_ONLY(temp1_recv_klass = noreg);  // These guys didn't load the recv_klass.

  }

  // Live registers at this point:

  //   member_reg       - MemberName that was the trailing argument.

  //   temp1_recv_klass - Klass of stacked receiver, if needed.

  //   Z_R10            - Interpreter linkage if interpreted.

  bool method_is_live = false;

  switch (iid) {

    case vmIntrinsics::_linkToSpecial:

      if (VerifyMethodHandles) {

        verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);

      }

      __ load_heap_oop(Z_method, member_vmtarget);

      __ z_lg(Z_method, vmtarget_method);

      method_is_live = true;

      break;

    case vmIntrinsics::_linkToStatic:

      if (VerifyMethodHandles) {

        verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);

      }

      __ load_heap_oop(Z_method, member_vmtarget);

      __ z_lg(Z_method, vmtarget_method);

      method_is_live = true;

      break;

    case vmIntrinsics::_linkToVirtual: {

      // Same as TemplateTable::invokevirtual, minus the CP setup and profiling.

      if (VerifyMethodHandles) {

        verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);

      }

      // Pick out the vtable index from the MemberName, and then we can discard it.

      Register temp2_index = temp2;

      __ z_lg(temp2_index, member_vmindex);

      if (VerifyMethodHandles) {

        // if (member_vmindex < 0) stop

        NearLabel L_index_ok;

        __ compare32_and_branch(temp2_index, constant(0), Assembler::bcondNotLow, L_index_ok);

        __ stop("no virtual index");

        __ BIND(L_index_ok);

      }

      // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget

      // at this point. And VerifyMethodHandles has already checked clazz, if needed.

      // Get target method and entry point.

      __ lookup_virtual_method(temp1_recv_klass, temp2_index, Z_method);

      method_is_live = true;

      break;

    }

    case vmIntrinsics::_linkToInterface: {

      // Same as TemplateTable::invokeinterface, minus the CP setup

      // and profiling, with different argument motion.

      if (VerifyMethodHandles) {

        verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);

      }

      Register temp3_intf = temp3;

      __ load_heap_oop(temp3_intf, member_clazz);

      load_klass_from_Class(_masm, temp3_intf, temp2, temp4);

      Register Z_index = Z_method;

      __ z_lg(Z_index, member_vmindex);

      if (VerifyMethodHandles) {

        NearLabel L;

        // if (member_vmindex < 0) stop

        __ compare32_and_branch(Z_index, constant(0), Assembler::bcondNotLow, L);

        __ stop("invalid vtable index for MH.invokeInterface");

        __ bind(L);

      }

      // Given interface, index, and recv klass, dispatch to the implementation method.

      Label L_no_such_interface;

      __ lookup_interface_method(temp1_recv_klass, temp3_intf,

                                 // Note: next two args must be the same:

                                 Z_index, Z_method, temp2, noreg,

                                 L_no_such_interface);

      jump_from_method_handle(_masm, Z_method, temp2, Z_R0, for_compiler_entry);

      __ bind(L_no_such_interface);

      // Throw exception.

      __ load_const_optimized(Z_R1, StubRoutines::throw_IncompatibleClassChangeError_entry());

      __ z_br(Z_R1);

      break;

    }

    default:

      fatal("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid));

      break;

  }

  if (method_is_live) {

    // Live at this point: Z_method, O5_savedSP (if interpreted).

    // After figuring out which concrete method to call, jump into it.

    // Note that this works in the interpreter with no data motion.

    // But the compiled version will require that rcx_recv be shifted out.

    jump_from_method_handle(_masm, Z_method, temp1, Z_R0, for_compiler_entry);

  }

}