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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 * 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 "code/debugInfo.hpp"
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#include "oops/access.hpp"
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#include "oops/compressedOops.inline.hpp"
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#include "oops/oop.hpp"
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#include "runtime/frame.inline.hpp"
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#include "runtime/globals.hpp"
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#include "runtime/handles.inline.hpp"
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#include "runtime/stackValue.hpp"
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#if INCLUDE_ZGC
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#include "gc/z/zBarrier.inline.hpp"
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#endif
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#if INCLUDE_SHENANDOAHGC
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#include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
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#endif
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class RegisterMap;
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class SmallRegisterMap;
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template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
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template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv);
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template<typename RegisterMapT>
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StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
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  return create_stack_value(sv, stack_value_address(fr, reg_map, sv), reg_map);
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}
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static oop oop_from_oop_location(stackChunkOop chunk, void* addr) {
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  if (addr == nullptr) {
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    return nullptr;
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  }
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  if (UseCompressedOops) {
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    // When compressed oops is enabled, an oop location may
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    // contain narrow oop values - we deal with that here
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    if (chunk != nullptr && chunk->has_bitmap()) {
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      // Transformed stack chunk with narrow oops
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      return chunk->load_oop((narrowOop*)addr);
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    }
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#ifdef _LP64
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    if (CompressedOops::is_base(*(void**)addr)) {
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      // Compiled code may produce decoded oop = narrow_oop_base
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      // when a narrow oop implicit null check is used.
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      // The narrow_oop_base could be null or be the address
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      // of the page below heap. Use null value for both cases.
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      return nullptr;
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    }
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#endif
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  }
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  if (chunk != nullptr) {
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    // Load oop from chunk
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    return chunk->load_oop((oop*)addr);
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  }
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  // Load oop from stack
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  oop val = *(oop*)addr;
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#if INCLUDE_SHENANDOAHGC
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  if (UseShenandoahGC) {
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    // Pass the value through the barrier to avoid capturing bad oops as
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    // stack values. Note: do not heal the location, to avoid accidentally
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    // corrupting the stack. Stack watermark barriers are supposed to handle
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    // the healing.
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    val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
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  }
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#endif
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  return val;
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}
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static oop oop_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
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  assert(UseCompressedOops, "Narrow oops should not exist");
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  assert(addr != nullptr, "Not expecting null address");
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  narrowOop* narrow_addr;
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  if (is_register) {
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    // The callee has no clue whether the register holds an int,
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    // long or is unused.  He always saves a long.  Here we know
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    // a long was saved, but we only want an int back.  Narrow the
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    // saved long to the int that the JVM wants.  We can't just
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    // use narrow_oop_cast directly, because we don't know what
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    // the high bits of the value might be.
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    narrow_addr = ((narrowOop*)addr) BIG_ENDIAN_ONLY(+ 1);
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  } else {
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    narrow_addr = (narrowOop*)addr;
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  }
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  if (chunk != nullptr) {
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    // Load oop from chunk
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    return chunk->load_oop(narrow_addr);
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  }
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  // Load oop from stack
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  oop val = CompressedOops::decode(*narrow_addr);
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#if INCLUDE_SHENANDOAHGC
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  if (UseShenandoahGC) {
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    // Pass the value through the barrier to avoid capturing bad oops as
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    // stack values. Note: do not heal the location, to avoid accidentally
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    // corrupting the stack. Stack watermark barriers are supposed to handle
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    // the healing.
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    val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
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  }
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#endif
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  return val;
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}
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StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) {
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  oop val = oop_from_oop_location(chunk, addr);
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  assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
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         p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
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  Handle h(Thread::current(), val); // Wrap a handle around the oop
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  return new StackValue(h);
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}
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StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
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  oop val = oop_from_narrowOop_location(chunk, addr, is_register);
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  assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
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         p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
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  Handle h(Thread::current(), val); // Wrap a handle around the oop
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  return new StackValue(h);
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}
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template<typename RegisterMapT>
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StackValue* StackValue::create_stack_value(ScopeValue* sv, address value_addr, const RegisterMapT* reg_map) {
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  stackChunkOop chunk = reg_map->stack_chunk()();
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  if (sv->is_location()) {
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    // Stack or register value
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    Location loc = ((LocationValue *)sv)->location();
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    // Then package it right depending on type
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    // Note: the transfer of the data is thru a union that contains
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    // an intptr_t. This is because an interpreter stack slot is
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    // really an intptr_t. The use of a union containing an intptr_t
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    // ensures that on a 64 bit platform we have proper alignment
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    // and that we store the value where the interpreter will expect
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    // to find it (i.e. proper endian). Similarly on a 32bit platform
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    // using the intptr_t ensures that when a value is larger than
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    // a stack slot (jlong/jdouble) that we capture the proper part
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    // of the value for the stack slot in question.
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    //
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    switch( loc.type() ) {
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    case Location::float_in_dbl: { // Holds a float in a double register?
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      // The callee has no clue whether the register holds a float,
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      // double or is unused.  He always saves a double.  Here we know
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      // a double was saved, but we only want a float back.  Narrow the
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      // saved double to the float that the JVM wants.
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      assert( loc.is_register(), "floats always saved to stack in 1 word" );
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      union { intptr_t p; jfloat jf; } value;
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      value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
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      value.jf = (jfloat) *(jdouble*) value_addr;
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      return new StackValue(value.p); // 64-bit high half is stack junk
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    }
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    case Location::int_in_long: { // Holds an int in a long register?
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      // The callee has no clue whether the register holds an int,
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      // long or is unused.  He always saves a long.  Here we know
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      // a long was saved, but we only want an int back.  Narrow the
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      // saved long to the int that the JVM wants.
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      assert( loc.is_register(), "ints always saved to stack in 1 word" );
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      union { intptr_t p; jint ji;} value;
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      value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
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      value.ji = (jint) *(jlong*) value_addr;
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      return new StackValue(value.p); // 64-bit high half is stack junk
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    }
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#ifdef _LP64
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    case Location::dbl:
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      // Double value in an aligned adjacent pair
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      return new StackValue(*(intptr_t*)value_addr);
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    case Location::lng:
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      // Long   value in an aligned adjacent pair
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      return new StackValue(*(intptr_t*)value_addr);
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    case Location::narrowoop:
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      return create_stack_value_from_narrowOop_location(reg_map->stack_chunk()(), (void*)value_addr, loc.is_register());
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#endif
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    case Location::oop:
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      return create_stack_value_from_oop_location(reg_map->stack_chunk()(), (void*)value_addr);
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    case Location::addr: {
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      loc.print_on(tty);
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      ShouldNotReachHere(); // both C1 and C2 now inline jsrs
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    }
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    case Location::normal: {
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      // Just copy all other bits straight through
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      union { intptr_t p; jint ji;} value;
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      value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
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      value.ji = *(jint*)value_addr;
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      return new StackValue(value.p);
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    }
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    case Location::invalid: {
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      return new StackValue();
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    }
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    case Location::vector: {
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      loc.print_on(tty);
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      ShouldNotReachHere(); // should be handled by VectorSupport::allocate_vector()
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    }
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    default:
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      loc.print_on(tty);
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      ShouldNotReachHere();
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    }
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  } else if (sv->is_constant_int()) {
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    // Constant int: treat same as register int.
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    union { intptr_t p; jint ji;} value;
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    value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
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    value.ji = (jint)((ConstantIntValue*)sv)->value();
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    return new StackValue(value.p);
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  } else if (sv->is_constant_oop()) {
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    // constant oop
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    return new StackValue(sv->as_ConstantOopReadValue()->value());
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#ifdef _LP64
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  } else if (sv->is_constant_double()) {
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    // Constant double in a single stack slot
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    union { intptr_t p; double d; } value;
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    value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
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    value.d = ((ConstantDoubleValue *)sv)->value();
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    return new StackValue(value.p);
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  } else if (sv->is_constant_long()) {
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    // Constant long in a single stack slot
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    union { intptr_t p; jlong jl; } value;
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    value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
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    value.jl = ((ConstantLongValue *)sv)->value();
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    return new StackValue(value.p);
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#endif
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  } else if (sv->is_object()) { // Scalar replaced object in compiled frame
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    ObjectValue* ov = (ObjectValue *)sv;
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    Handle hdl = ov->value();
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    return new StackValue(hdl, hdl.is_null() && ov->is_scalar_replaced() ? 1 : 0);
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  } else if (sv->is_marker()) {
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    // Should never need to directly construct a marker.
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    ShouldNotReachHere();
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  }
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  // Unknown ScopeValue type
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  ShouldNotReachHere();
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  return new StackValue((intptr_t) 0);   // dummy
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}
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template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
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template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv);
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template<typename RegisterMapT>
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address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
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  if (!sv->is_location()) {
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    return nullptr;
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  }
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  Location loc = ((LocationValue *)sv)->location();
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  if (loc.type() == Location::invalid) {
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    return nullptr;
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  }
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  if (!reg_map->in_cont()) {
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    address value_addr = loc.is_register()
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      // Value was in a callee-save register
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      ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()), fr->sp())
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      // Else value was directly saved on the stack. The frame's original stack pointer,
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      // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
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      : ((address)fr->unextended_sp()) + loc.stack_offset();
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    assert(value_addr == nullptr || reg_map->thread() == nullptr || reg_map->thread()->is_in_usable_stack(value_addr), INTPTR_FORMAT, p2i(value_addr));
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    return value_addr;
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  }
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  address value_addr = loc.is_register()
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    ? reg_map->as_RegisterMap()->stack_chunk()->reg_to_location(*fr, reg_map->as_RegisterMap(), VMRegImpl::as_VMReg(loc.register_number()))
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    : reg_map->as_RegisterMap()->stack_chunk()->usp_offset_to_location(*fr, loc.stack_offset());
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  assert(value_addr == nullptr || Continuation::is_in_usable_stack(value_addr, reg_map->as_RegisterMap()) || (reg_map->thread() != nullptr && reg_map->thread()->is_in_usable_stack(value_addr)), INTPTR_FORMAT, p2i(value_addr));
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  return value_addr;
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}
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BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
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  assert(location.is_stack(), "for now we only look at the stack");
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  int word_offset = location.stack_offset() / wordSize;
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  // (stack picture)
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  // high: [     ]  word_offset + 1
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  // low   [     ]  word_offset
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  //
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  // sp->  [     ]  0
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  // the word_offset is the distance from the stack pointer to the lowest address
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  // The frame's original stack pointer, before any extension by its callee
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  // (due to Compiler1 linkage on SPARC), must be used.
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  return (BasicLock*) (fr->unextended_sp() + word_offset);
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}
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#ifndef PRODUCT
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void StackValue::print_on(outputStream* st) const {
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  switch(_type) {
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    case T_INT:
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      st->print("%d (int) %f (float) %x (hex)",  *(int *)&_integer_value, *(float *)&_integer_value,  *(int *)&_integer_value);
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      break;
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    case T_OBJECT:
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      if (_handle_value() != nullptr) {
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        _handle_value()->print_value_on(st);
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      } else {
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        st->print("null");
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      }
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      st->print(" <" INTPTR_FORMAT ">", p2i(_handle_value()));
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      break;
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    case T_CONFLICT:
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     st->print("conflict");
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     break;
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    default:
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     ShouldNotReachHere();
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  }
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}
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#endif
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