/*

 * Copyright (c) 1997, 2015, 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 "asm/macroAssembler.inline.hpp"

#include "classfile/javaClasses.inline.hpp"

#include "interpreter/interpreter.hpp"

#include "memory/allocation.inline.hpp"

#include "prims/methodHandles.hpp"

#define __ _masm->

#ifdef PRODUCT

#define BLOCK_COMMENT(str) // nothing

#else

#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.

inline 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");

  }

  __ ld(klass_reg, java_lang_Class::klass_offset_in_bytes(), klass_reg);

}

#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 //ASSERT

#define NONZERO(x) (x)

#endif //ASSERT

#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);

  KlassHandle klass = SystemDictionary::well_known_klass(klass_id);

  Label L_ok, L_bad;

  BLOCK_COMMENT("verify_klass {");

  __ verify_oop(obj_reg);

  __ cmpdi(CCR0, obj_reg, 0);

  __ beq(CCR0, L_bad);

  __ load_klass(temp_reg, obj_reg);

  __ load_const_optimized(temp2_reg, (address) klass_addr);

  __ ld(temp2_reg, 0, temp2_reg);

  __ cmpd(CCR0, temp_reg, temp2_reg);

  __ beq(CCR0, L_ok);

  __ ld(temp_reg, klass->super_check_offset(), temp_reg);

  __ cmpd(CCR0, temp_reg, temp2_reg);

  __ beq(CCR0, 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) {

  Label L;

  BLOCK_COMMENT("verify_ref_kind {");

  __ load_sized_value(temp, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes()), member_reg,

                      sizeof(u4), /*is_signed*/ false);

  // assert(sizeof(u4) == sizeof(java.lang.invoke.MemberName.flags), "");

  __ srwi( temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);

  __ andi(temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);

  __ cmpwi(CCR1, temp, ref_kind);

  __ beq(CCR1, 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) {

  Label L_no_such_method;

  assert(method == R19_method, "interpreter calling convention");

  assert_different_registers(method, target, temp);

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

    Label run_compiled_code;

    // 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();

    __ lwz(temp, in_bytes(JavaThread::interp_only_mode_offset()), R16_thread);

    __ cmplwi(CCR0, temp, 0);

    __ beq(CCR0, run_compiled_code);

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

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

    __ cmplwi(CCR0, R19_method, 0);

    __ beq(CCR0, L_no_such_method);

    __ ld(target, in_bytes(Method::interpreter_entry_offset()), R19_method);

    __ mtctr(target);

    __ bctr();

    __ BIND(run_compiled_code);

  }

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

  __ cmplwi(CCR0, R19_method, 0);

  __ beq(CCR0, L_no_such_method);

  const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :

                                                     Method::from_interpreted_offset();

  __ ld(target, in_bytes(entry_offset), R19_method);

  __ mtctr(target);

  __ bctr();

  __ bind(L_no_such_method);

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

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

  __ mtctr(target);

  __ bctr();

}

void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,

                                        Register recv, Register method_temp,

                                        Register temp2, Register temp3,

                                        bool for_compiler_entry) {

  BLOCK_COMMENT("jump_to_lambda_form {");

  // 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 is only passed on

  assert(method_temp == R19_method, "required register for loading method");

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

  __ verify_oop(recv);

  __ load_heap_oop_not_null(method_temp, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes()), recv, temp2);

  __ verify_oop(method_temp);

  __ load_heap_oop_not_null(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes()), method_temp, temp2);

  __ verify_oop(method_temp);

  // The following assumes that a Method* is normally compressed in the vmtarget field:

  __ ld(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), method_temp);

  if (VerifyMethodHandles && !for_compiler_entry) {

    // Make sure recv is already on stack.

    __ ld(temp2, in_bytes(Method::const_offset()), method_temp);

    __ load_sized_value(temp2, in_bytes(ConstMethod::size_of_parameters_offset()), temp2,

                        sizeof(u2), /*is_signed*/ false);

    // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");

    Label L;

    __ ld(temp2, __ argument_offset(temp2, temp2, 0), R15_esp);

    __ cmpd(CCR1, temp2, recv);

    __ beq(CCR1, L);

    __ stop("receiver not on stack");

    __ BIND(L);

  }

  jump_from_method_handle(_masm, method_temp, temp2, temp3, 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.

    __ stop("Should not reach here");           // empty stubs make SG sick

    return NULL;

  }

  Register argbase    = R15_esp; // parameter (preserved)

  Register argslot    = R3;

  Register temp1      = R6;

  Register param_size = R7;

  // here's where control starts out:

  __ align(CodeEntryAlignment);

  address entry_point = __ pc();

  if (VerifyMethodHandles) {

    assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");

    Label L;

    BLOCK_COMMENT("verify_intrinsic_id {");

    __ load_sized_value(temp1, Method::intrinsic_id_offset_in_bytes(), R19_method,

                        sizeof(u2), /*is_signed*/ false);

    __ cmpwi(CCR1, temp1, (int) iid);

    __ beq(CCR1, 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.

  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)) {

    __ ld(param_size, in_bytes(Method::const_offset()), R19_method);

    __ load_sized_value(param_size, in_bytes(ConstMethod::size_of_parameters_offset()), param_size,

                        sizeof(u2), /*is_signed*/ false);

    // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");

  } else {

    DEBUG_ONLY(param_size = noreg);

  }

  Register tmp_mh = noreg;

  if (!is_signature_polymorphic_static(iid)) {

    __ ld(tmp_mh = temp1, __ argument_offset(param_size, param_size, 0), argbase);

    DEBUG_ONLY(param_size = noreg);

  }

  if (TraceMethodHandles) {

    if (tmp_mh != noreg) {

      __ mr(R23_method_handle, tmp_mh);  // make stub happy

    }

    trace_method_handle_interpreter_entry(_masm, iid);

  }

  if (iid == vmIntrinsics::_invokeBasic) {

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

  } else {

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

    Register tmp_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.

      __ ld(tmp_recv = temp1, __ argument_offset(param_size, param_size, 0), argbase);

      DEBUG_ONLY(param_size = noreg);

    }

    Register R19_member = R19_method;  // MemberName ptr; incoming method ptr is dead now

    __ ld(R19_member, RegisterOrConstant((intptr_t)8), argbase);

    __ add(argbase, Interpreter::stackElementSize, argbase);

    generate_method_handle_dispatch(_masm, iid, tmp_recv, R19_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 ? R25_tmp5 : R7);

  Register temp2 = (for_compiler_entry ? R22_tmp2 : R8);

  Register temp3 = (for_compiler_entry ? R23_tmp3 : R9);

  Register temp4 = (for_compiler_entry ? R24_tmp4 : R10);

  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 (iid == vmIntrinsics::_invokeBasic) {

    // indirect through MH.form.vmentry.vmtarget

    jump_to_lambda_form(_masm, receiver_reg, R19_method, temp1, temp2, for_compiler_entry);

  } else {

    // 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.");

    }

    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_throw(receiver_reg, -1, temp1,

                            Interpreter::throw_NullPointerException_entry());

      } else {

        // load receiver klass itself

        __ null_check_throw(receiver_reg, oopDesc::klass_offset_in_bytes(), temp1,

                            Interpreter::throw_NullPointerException_entry());

        __ 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) {

        Label L_ok;

        Register temp2_defc = temp2;

        __ load_heap_oop_not_null(temp2_defc, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()), member_reg, temp3);

        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

    //  O5_savedSP - interpreter linkage (if interpreted)

    //  O0..O5 - compiler arguments (if compiled)

    Label L_incompatible_class_change_error;

    switch (iid) {

    case vmIntrinsics::_linkToSpecial:

      if (VerifyMethodHandles) {

        verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp2);

      }

      __ ld(R19_method, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), member_reg);

      break;

    case vmIntrinsics::_linkToStatic:

      if (VerifyMethodHandles) {

        verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp2);

      }

      __ ld(R19_method, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), member_reg);

      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, temp2);

      }

      // pick out the vtable index from the MemberName, and then we can discard it:

      Register temp2_index = temp2;

      __ ld(temp2_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()), member_reg);

      if (VerifyMethodHandles) {

        Label L_index_ok;

        __ cmpdi(CCR1, temp2_index, 0);

        __ bge(CCR1, 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* & entry point

      __ lookup_virtual_method(temp1_recv_klass, temp2_index, R19_method);

      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, temp2);

      }

      Register temp2_intf = temp2;

      __ load_heap_oop_not_null(temp2_intf, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()), member_reg, temp3);

      load_klass_from_Class(_masm, temp2_intf, temp3, temp4);

      __ verify_klass_ptr(temp2_intf);

      Register vtable_index = R19_method;

      __ ld(vtable_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()), member_reg);

      if (VerifyMethodHandles) {

        Label L_index_ok;

        __ cmpdi(CCR1, vtable_index, 0);

        __ bge(CCR1, L_index_ok);

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

        __ BIND(L_index_ok);

      }

      // given intf, index, and recv klass, dispatch to the implementation method

      __ lookup_interface_method(temp1_recv_klass, temp2_intf,

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

                                 vtable_index, R19_method,

                                 temp3, temp4,

                                 L_incompatible_class_change_error);

      break;

    }

    default:

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

      break;

    }

    // Live at this point:

    //   R19_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.

    __ verify_method_ptr(R19_method);

    jump_from_method_handle(_masm, R19_method, temp1, temp2, for_compiler_entry);

    if (iid == vmIntrinsics::_linkToInterface) {

      __ BIND(L_incompatible_class_change_error);

      __ load_const_optimized(temp1, StubRoutines::throw_IncompatibleClassChangeError_entry());

      __ mtctr(temp1);

      __ bctr();

    }

  }

}

#ifndef PRODUCT

void trace_method_handle_stub(const char* adaptername,

                              oopDesc* mh,

                              intptr_t* entry_sp,

                              intptr_t* saved_regs) {

  bool has_mh = (strstr(adaptername, "/static") == NULL &&

                 strstr(adaptername, "linkTo") == NULL);    // static linkers don't have MH

  const char* mh_reg_name = has_mh ? "R23_method_handle" : "G23";

  tty->print_cr("MH %s %s=" INTPTR_FORMAT " sp=" INTPTR_FORMAT,

                adaptername, mh_reg_name, p2i(mh), p2i(entry_sp));

  if (Verbose) {

    tty->print_cr("Registers:");

    const int abi_offset = frame::abi_reg_args_size / 8;

    for (int i = R3->encoding(); i <= R12->encoding(); i++) {

      Register r = as_Register(i);

      int count = i - R3->encoding();

      // The registers are stored in reverse order on the stack (by save_volatile_gprs(R1_SP, abi_reg_args_size)).

      tty->print("%3s=" PTR_FORMAT, r->name(), saved_regs[abi_offset + count]);

      if ((count + 1) % 4 == 0) {

        tty->cr();

      } else {

        tty->print(", ");

      }

    }

    tty->cr();

    {

      // dumping last frame with frame::describe

      JavaThread* p = JavaThread::active();

      ResourceMark rm;

      PRESERVE_EXCEPTION_MARK; // may not be needed by safer and unexpensive here

      FrameValues values;

      // Note: We want to allow trace_method_handle from any call site.

      // While trace_method_handle creates a frame, it may be entered

      // without a PC on the stack top (e.g. not just after a call).

      // Walking that frame could lead to failures due to that invalid PC.

      // => carefully detect that frame when doing the stack walking

      // Current C frame

      frame cur_frame = os::current_frame();

      // Robust search of trace_calling_frame (independant of inlining).

      assert(cur_frame.sp() <= saved_regs, "registers not saved on stack ?");

      frame trace_calling_frame = os::get_sender_for_C_frame(&cur_frame);

      while (trace_calling_frame.fp() < saved_regs) {

        trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame);

      }

      // Safely create a frame and call frame::describe.

      intptr_t *dump_sp = trace_calling_frame.sender_sp();

      frame dump_frame = frame(dump_sp);

      dump_frame.describe(values, 1);

      values.describe(-1, saved_regs, "raw top of stack");

      tty->print_cr("Stack layout:");

      values.print(p);

    }