jdk

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/*
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 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
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 * Copyright (c) 2014, Red Hat Inc. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#include "asm/macroAssembler.hpp"
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#include "classfile/javaClasses.inline.hpp"
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#include "classfile/vmClasses.hpp"
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#include "interpreter/interpreter.hpp"
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#include "interpreter/interpreterRuntime.hpp"
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#include "memory/allocation.inline.hpp"
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#include "prims/jvmtiExport.hpp"
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#include "prims/methodHandles.hpp"
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#include "runtime/flags/flagSetting.hpp"
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#include "runtime/frame.inline.hpp"
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#include "runtime/stubRoutines.hpp"
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#define __ _masm->
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#ifdef PRODUCT
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#define BLOCK_COMMENT(str) /* nothing */
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#else
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#define BLOCK_COMMENT(str) __ block_comment(str)
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#endif
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#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
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void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
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  if (VerifyMethodHandles)
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    verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class),
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                 "MH argument is a Class");
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  __ ldr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset()));
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}
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#ifdef ASSERT
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static int check_nonzero(const char* xname, int x) {
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  assert(x != 0, "%s should be nonzero", xname);
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  return x;
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}
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#define NONZERO(x) check_nonzero(#x, x)
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#else //ASSERT
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#define NONZERO(x) (x)
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#endif //PRODUCT
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#ifdef ASSERT
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void MethodHandles::verify_klass(MacroAssembler* _masm,
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                                 Register obj, vmClassID klass_id,
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                                 const char* error_message) {
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  InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
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  Klass* klass = vmClasses::klass_at(klass_id);
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  Register temp = rscratch2;
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  Register temp2 = rscratch1; // used by MacroAssembler::cmpptr
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  Label L_ok, L_bad;
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  BLOCK_COMMENT("verify_klass {");
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  __ verify_oop(obj);
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  __ cbz(obj, L_bad);
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  __ push(RegSet::of(temp, temp2), sp);
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  __ load_klass(temp, obj);
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  __ cmpptr(temp, ExternalAddress((address) klass_addr));
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  __ br(Assembler::EQ, L_ok);
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  intptr_t super_check_offset = klass->super_check_offset();
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  __ ldr(temp, Address(temp, super_check_offset));
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  __ cmpptr(temp, ExternalAddress((address) klass_addr));
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  __ br(Assembler::EQ, L_ok);
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  __ pop(RegSet::of(temp, temp2), sp);
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  __ bind(L_bad);
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  __ stop(error_message);
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  __ BIND(L_ok);
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  __ pop(RegSet::of(temp, temp2), sp);
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  BLOCK_COMMENT("} verify_klass");
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}
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void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {  }
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#endif //ASSERT
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void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
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                                            bool for_compiler_entry) {
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  assert(method == rmethod, "interpreter calling convention");
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  Label L_no_such_method;
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  __ cbz(rmethod, L_no_such_method);
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  __ verify_method_ptr(method);
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  if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
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    Label run_compiled_code;
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    // JVMTI events, such as single-stepping, are implemented partly by avoiding running
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    // compiled code in threads for which the event is enabled.  Check here for
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    // interp_only_mode if these events CAN be enabled.
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    __ ldrw(rscratch1, Address(rthread, JavaThread::interp_only_mode_offset()));
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    __ cbzw(rscratch1, run_compiled_code);
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    __ ldr(rscratch1, Address(method, Method::interpreter_entry_offset()));
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    __ br(rscratch1);
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    __ BIND(run_compiled_code);
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  }
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  const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
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                                                     Method::from_interpreted_offset();
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  __ ldr(rscratch1,Address(method, entry_offset));
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  __ br(rscratch1);
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  __ bind(L_no_such_method);
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  __ far_jump(RuntimeAddress(StubRoutines::throw_AbstractMethodError_entry()));
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}
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void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
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                                        Register recv, Register method_temp,
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                                        Register temp2,
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                                        bool for_compiler_entry) {
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  BLOCK_COMMENT("jump_to_lambda_form {");
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  // This is the initial entry point of a lazy method handle.
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  // After type checking, it picks up the invoker from the LambdaForm.
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  assert_different_registers(recv, method_temp, temp2);
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  assert(recv != noreg, "required register");
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  assert(method_temp == rmethod, "required register for loading method");
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  // Load the invoker, as MH -> MH.form -> LF.vmentry
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  __ verify_oop(recv);
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  __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2, rscratch2);
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  __ verify_oop(method_temp);
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  __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2, rscratch2);
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  __ verify_oop(method_temp);
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  __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2, rscratch2);
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  __ verify_oop(method_temp);
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  __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
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  if (VerifyMethodHandles && !for_compiler_entry) {
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    // make sure recv is already on stack
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    __ ldr(temp2, Address(method_temp, Method::const_offset()));
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    __ load_sized_value(temp2,
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                        Address(temp2, ConstMethod::size_of_parameters_offset()),
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                        sizeof(u2), /*is_signed*/ false);
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    // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
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    Label L;
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    __ ldr(rscratch1, __ argument_address(temp2, -1));
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    __ cmpoop(recv, rscratch1);
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    __ br(Assembler::EQ, L);
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    __ ldr(r0, __ argument_address(temp2, -1));
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    __ hlt(0);
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    __ BIND(L);
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  }
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  jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
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  BLOCK_COMMENT("} jump_to_lambda_form");
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}
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// Code generation
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address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
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                                                                vmIntrinsics::ID iid) {
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  const bool not_for_compiler_entry = false;  // this is the interpreter entry
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  assert(is_signature_polymorphic(iid), "expected invoke iid");
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  if (iid == vmIntrinsics::_invokeGeneric ||
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      iid == vmIntrinsics::_compiledLambdaForm) {
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    // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
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    // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
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    // They all allow an appendix argument.
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    __ hlt(0);           // empty stubs make SG sick
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    return nullptr;
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  }
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  // No need in interpreter entry for linkToNative for now.
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  // Interpreter calls compiled entry through i2c.
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  if (iid == vmIntrinsics::_linkToNative) {
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    __ hlt(0);
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    return nullptr;
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  }
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  // r19_sender_sp: sender SP (must preserve; see prepare_to_jump_from_interpreted)
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  // rmethod: Method*
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  // r3: argument locator (parameter slot count, added to rsp)
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  // r1: used as temp to hold mh or receiver
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  // r0, r11: garbage temps, blown away
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  Register argp   = r3;   // argument list ptr, live on error paths
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  Register temp   = r0;
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  Register mh     = r1;   // MH receiver; dies quickly and is recycled
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  // here's where control starts out:
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  __ align(CodeEntryAlignment);
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  address entry_point = __ pc();
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  if (VerifyMethodHandles) {
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    assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
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    Label L;
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    BLOCK_COMMENT("verify_intrinsic_id {");
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    __ ldrh(rscratch1, Address(rmethod, Method::intrinsic_id_offset()));
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    __ subs(zr, rscratch1, (int) iid);
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    __ br(Assembler::EQ, L);
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    if (iid == vmIntrinsics::_linkToVirtual ||
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        iid == vmIntrinsics::_linkToSpecial) {
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      // could do this for all kinds, but would explode assembly code size
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      trace_method_handle(_masm, "bad Method*::intrinsic_id");
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    }
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    __ hlt(0);
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    __ bind(L);
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    BLOCK_COMMENT("} verify_intrinsic_id");
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  }
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  // First task:  Find out how big the argument list is.
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  Address r3_first_arg_addr;
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  int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
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  assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
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  if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
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    __ ldr(argp, Address(rmethod, Method::const_offset()));
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    __ load_sized_value(argp,
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                        Address(argp, ConstMethod::size_of_parameters_offset()),
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                        sizeof(u2), /*is_signed*/ false);
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    // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
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    r3_first_arg_addr = __ argument_address(argp, -1);
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  } else {
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    DEBUG_ONLY(argp = noreg);
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  }
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  if (!is_signature_polymorphic_static(iid)) {
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    __ ldr(mh, r3_first_arg_addr);
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    DEBUG_ONLY(argp = noreg);
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  }
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  // r3_first_arg_addr is live!
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  trace_method_handle_interpreter_entry(_masm, iid);
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  if (iid == vmIntrinsics::_invokeBasic) {
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    generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
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  } else {
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    // Adjust argument list by popping the trailing MemberName argument.
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    Register recv = noreg;
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    if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
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      // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
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      __ ldr(recv = r2, r3_first_arg_addr);
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    }
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    DEBUG_ONLY(argp = noreg);
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    Register rmember = rmethod;  // MemberName ptr; incoming method ptr is dead now
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    __ pop(rmember);             // extract last argument
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    generate_method_handle_dispatch(_masm, iid, recv, rmember, not_for_compiler_entry);
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  }
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  return entry_point;
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}
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void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
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  BLOCK_COMMENT("jump_to_native_invoker {");
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  assert_different_registers(nep_reg, temp_target);
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  assert(nep_reg != noreg, "required register");
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  // Load the invoker, as NEP -> .invoker
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  __ verify_oop(nep_reg);
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  __ access_load_at(T_ADDRESS, IN_HEAP, temp_target,
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                    Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())),
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                    noreg, noreg);
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  __ br(temp_target);
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  BLOCK_COMMENT("} jump_to_native_invoker");
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}
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void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
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                                                    vmIntrinsics::ID iid,
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                                                    Register receiver_reg,
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                                                    Register member_reg,
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                                                    bool for_compiler_entry) {
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  assert(is_signature_polymorphic(iid), "expected invoke iid");
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  // temps used in this code are not used in *either* compiled or interpreted calling sequences
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  Register temp1 = r10;
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  Register temp2 = r11;
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  Register temp3 = r14;
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  if (for_compiler_entry) {
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    assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
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    assert_different_registers(temp1,        j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
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    assert_different_registers(temp2,        j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
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    assert_different_registers(temp3,        j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
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  }
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  assert_different_registers(temp1, temp2, temp3, receiver_reg);
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  assert_different_registers(temp1, temp2, temp3, member_reg);
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297
  if (iid == vmIntrinsics::_invokeBasic) {
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    // indirect through MH.form.vmentry.vmtarget
299
    jump_to_lambda_form(_masm, receiver_reg, rmethod, temp1, for_compiler_entry);
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301
  } else if (iid == vmIntrinsics::_linkToNative) {
302
    assert(for_compiler_entry, "only compiler entry is supported");
303
    jump_to_native_invoker(_masm, member_reg, temp1);
304
  } else {
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    // The method is a member invoker used by direct method handles.
306
    if (VerifyMethodHandles) {
307
      // make sure the trailing argument really is a MemberName (caller responsibility)
308
      verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
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                   "MemberName required for invokeVirtual etc.");
310
    }
311

312
    Address member_clazz(    member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
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    Address member_vmindex(  member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
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    Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
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    Address vmtarget_method( rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
316

317
    Register temp1_recv_klass = temp1;
318
    if (iid != vmIntrinsics::_linkToStatic) {
319
      __ verify_oop(receiver_reg);
320
      if (iid == vmIntrinsics::_linkToSpecial) {
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        // Don't actually load the klass; just null-check the receiver.
322
        __ null_check(receiver_reg);
323
      } else {
324
        // load receiver klass itself
325
        __ load_klass(temp1_recv_klass, receiver_reg);
326
        __ verify_klass_ptr(temp1_recv_klass);
327
      }
328
      BLOCK_COMMENT("check_receiver {");
329
      // The receiver for the MemberName must be in receiver_reg.
330
      // Check the receiver against the MemberName.clazz
331
      if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
332
        // Did not load it above...
333
        __ load_klass(temp1_recv_klass, receiver_reg);
334
        __ verify_klass_ptr(temp1_recv_klass);
335
      }
336
      if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
337
        Label L_ok;
338
        Register temp2_defc = temp2;
339
        __ load_heap_oop(temp2_defc, member_clazz, temp3, rscratch2);
340
        load_klass_from_Class(_masm, temp2_defc);
341
        __ verify_klass_ptr(temp2_defc);
342
        __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
343
        // If we get here, the type check failed!
344
        __ hlt(0);
345
        // __ STOP("receiver class disagrees with MemberName.clazz");
346
        __ bind(L_ok);
347
      }
348
      BLOCK_COMMENT("} check_receiver");
349
    }
350
    if (iid == vmIntrinsics::_linkToSpecial ||
351
        iid == vmIntrinsics::_linkToStatic) {
352
      DEBUG_ONLY(temp1_recv_klass = noreg);  // these guys didn't load the recv_klass
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    }
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355
    // Live registers at this point:
356
    //  member_reg - MemberName that was the trailing argument
357
    //  temp1_recv_klass - klass of stacked receiver, if needed
358
    //  r19 - interpreter linkage (if interpreted)
359
    //  r1 ... r0 - compiler arguments (if compiled)
360

361
    Label L_incompatible_class_change_error;
362
    switch (iid) {
363
    case vmIntrinsics::_linkToSpecial:
364
      if (VerifyMethodHandles) {
365
        verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
366
      }
367
      __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
368
      __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
369
      break;
370

371
    case vmIntrinsics::_linkToStatic:
372
      if (VerifyMethodHandles) {
373
        verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
374
      }
375
      __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
376
      __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
377
      break;
378

379
    case vmIntrinsics::_linkToVirtual:
380
    {
381
      // same as TemplateTable::invokevirtual,
382
      // minus the CP setup and profiling:
383

384
      if (VerifyMethodHandles) {
385
        verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
386
      }
387

388
      // pick out the vtable index from the MemberName, and then we can discard it:
389
      Register temp2_index = temp2;
390
      __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
391

392
      if (VerifyMethodHandles) {
393
        Label L_index_ok;
394
        __ cmpw(temp2_index, 0U);
395
        __ br(Assembler::GE, L_index_ok);
396
        __ hlt(0);
397
        __ BIND(L_index_ok);
398
      }
399

400
      // Note:  The verifier invariants allow us to ignore MemberName.clazz and vmtarget
401
      // at this point.  And VerifyMethodHandles has already checked clazz, if needed.
402

403
      // get target Method* & entry point
404
      __ lookup_virtual_method(temp1_recv_klass, temp2_index, rmethod);
405
      break;
406
    }
407

408
    case vmIntrinsics::_linkToInterface:
409
    {
410
      // same as TemplateTable::invokeinterface
411
      // (minus the CP setup and profiling, with different argument motion)
412
      if (VerifyMethodHandles) {
413
        verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
414
      }
415

416
      Register temp3_intf = temp3;
417
      __ load_heap_oop(temp3_intf, member_clazz, temp2, rscratch2);
418
      load_klass_from_Class(_masm, temp3_intf);
419
      __ verify_klass_ptr(temp3_intf);
420

421
      Register rindex = rmethod;
422
      __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
423
      if (VerifyMethodHandles) {
424
        Label L;
425
        __ cmpw(rindex, 0U);
426
        __ br(Assembler::GE, L);
427
        __ hlt(0);
428
        __ bind(L);
429
      }
430

431
      // given intf, index, and recv klass, dispatch to the implementation method
432
      __ lookup_interface_method(temp1_recv_klass, temp3_intf,
433
                                 // note: next two args must be the same:
434
                                 rindex, rmethod,
435
                                 temp2,
436
                                 L_incompatible_class_change_error);
437
      break;
438
    }
439

440
    default:
441
      fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
442
      break;
443
    }
444

445
    // live at this point:  rmethod, r19_sender_sp (if interpreted)
446

447
    // After figuring out which concrete method to call, jump into it.
448
    // Note that this works in the interpreter with no data motion.
449
    // But the compiled version will require that r2_recv be shifted out.
450
    __ verify_method_ptr(rmethod);
451
    jump_from_method_handle(_masm, rmethod, temp1, for_compiler_entry);
452
    if (iid == vmIntrinsics::_linkToInterface) {
453
      __ bind(L_incompatible_class_change_error);
454
      __ far_jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
455
    }
456
  }
457
}
458

459
#ifndef PRODUCT
460
void trace_method_handle_stub(const char* adaptername,
461
                              oopDesc* mh,
462
                              intptr_t* saved_regs,
463
                              intptr_t* entry_sp) {  }
464

465
// The stub wraps the arguments in a struct on the stack to avoid
466
// dealing with the different calling conventions for passing 6
467
// arguments.
468
struct MethodHandleStubArguments {
469
  const char* adaptername;
470
  oopDesc* mh;
471
  intptr_t* saved_regs;
472
  intptr_t* entry_sp;
473
};
474
void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) {  }
475

476
void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {  }
477
#endif //PRODUCT
478