jdk

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/*
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 * Copyright (c) 1997, 2024, 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 "asm/codeBuffer.hpp"
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#include "code/compiledIC.hpp"
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#include "code/oopRecorder.inline.hpp"
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#include "compiler/disassembler.hpp"
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#include "logging/log.hpp"
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#include "oops/klass.inline.hpp"
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#include "oops/methodData.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/icache.hpp"
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#include "runtime/safepointVerifiers.hpp"
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#include "utilities/align.hpp"
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#include "utilities/copy.hpp"
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#include "utilities/powerOfTwo.hpp"
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#include "utilities/xmlstream.hpp"
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// The structure of a CodeSection:
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//
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//    _start ->           +----------------+
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//                        | machine code...|
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//    _end ->             |----------------|
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//                        |                |
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//                        |    (empty)     |
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//                        |                |
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//                        |                |
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//                        +----------------+
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//    _limit ->           |                |
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//
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//    _locs_start ->      +----------------+
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//                        |reloc records...|
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//                        |----------------|
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//    _locs_end ->        |                |
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//                        |                |
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//                        |    (empty)     |
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//                        |                |
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//                        |                |
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//                        +----------------+
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//    _locs_limit ->      |                |
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// The _end (resp. _limit) pointer refers to the first
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// unused (resp. unallocated) byte.
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// The structure of the CodeBuffer while code is being accumulated:
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//
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//    _total_start ->    \
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//    _consts._start ->             +----------------+
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//                                  |                |
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//                                  |   Constants    |
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//                                  |                |
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//    _insts._start ->              |----------------|
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//                                  |                |
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//                                  |     Code       |
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//                                  |                |
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//    _stubs._start ->              |----------------|
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//                                  |                |
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//                                  |    Stubs       | (also handlers for deopt/exception)
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//                                  |                |
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//                                  +----------------+
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//    + _total_size ->              |                |
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//
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// When the code and relocations are copied to the code cache,
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// the empty parts of each section are removed, and everything
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// is copied into contiguous locations.
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typedef CodeBuffer::csize_t csize_t;  // file-local definition
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// External buffer, in a predefined CodeBlob.
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// Important: The code_start must be taken exactly, and not realigned.
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CodeBuffer::CodeBuffer(CodeBlob* blob) DEBUG_ONLY(: Scrubber(this, sizeof(*this))) {
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  // Provide code buffer with meaningful name
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  initialize_misc(blob->name());
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  initialize(blob->content_begin(), blob->content_size());
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  debug_only(verify_section_allocation();)
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}
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void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
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  // Always allow for empty slop around each section.
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  int slop = (int) CodeSection::end_slop();
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  assert(SECT_LIMIT == 3, "total_size explicitly lists all section alignments");
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  int total_size = code_size + _consts.alignment() + _insts.alignment() + _stubs.alignment() + SECT_LIMIT * slop;
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  assert(blob() == nullptr, "only once");
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  set_blob(BufferBlob::create(_name, total_size));
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  if (blob() == nullptr) {
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    // The assembler constructor will throw a fatal on an empty CodeBuffer.
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    return;  // caller must test this
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  }
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  // Set up various pointers into the blob.
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  initialize(_total_start, _total_size);
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  assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
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  pd_initialize();
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  if (locs_size != 0) {
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    _insts.initialize_locs(locs_size / sizeof(relocInfo));
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  }
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  debug_only(verify_section_allocation();)
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}
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CodeBuffer::~CodeBuffer() {
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  verify_section_allocation();
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  // If we allocated our code buffer from the CodeCache via a BufferBlob, and
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  // it's not permanent, then free the BufferBlob.  The rest of the memory
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  // will be freed when the ResourceObj is released.
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  for (CodeBuffer* cb = this; cb != nullptr; cb = cb->before_expand()) {
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    // Previous incarnations of this buffer are held live, so that internal
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    // addresses constructed before expansions will not be confused.
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    cb->free_blob();
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  }
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  if (_overflow_arena != nullptr) {
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    // free any overflow storage
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    delete _overflow_arena;
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  }
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  if (_shared_trampoline_requests != nullptr) {
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    delete _shared_trampoline_requests;
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  }
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  NOT_PRODUCT(clear_strings());
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}
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void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
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  assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
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  DEBUG_ONLY(_default_oop_recorder.freeze());  // force unused OR to be frozen
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  _oop_recorder = r;
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}
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void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
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  assert(cs != &_insts, "insts is the memory provider, not the consumer");
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  csize_t slop = CodeSection::end_slop();  // margin between sections
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  int align = cs->alignment();
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  assert(is_power_of_2(align), "sanity");
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  address start  = _insts._start;
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  address limit  = _insts._limit;
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  address middle = limit - size;
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  middle -= (intptr_t)middle & (align-1);  // align the division point downward
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  guarantee(middle - slop > start, "need enough space to divide up");
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  _insts._limit = middle - slop;  // subtract desired space, plus slop
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  cs->initialize(middle, limit - middle);
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  assert(cs->start() == middle, "sanity");
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  assert(cs->limit() == limit,  "sanity");
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  // give it some relocations to start with, if the main section has them
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  if (_insts.has_locs())  cs->initialize_locs(1);
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}
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void CodeBuffer::set_blob(BufferBlob* blob) {
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  _blob = blob;
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  if (blob != nullptr) {
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    address start = blob->content_begin();
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    address end   = blob->content_end();
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    // Round up the starting address.
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    int align = _insts.alignment();
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    start += (-(intptr_t)start) & (align-1);
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    _total_start = start;
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    _total_size  = end - start;
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  } else {
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#ifdef ASSERT
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    // Clean out dangling pointers.
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    _total_start    = badAddress;
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    _consts._start  = _consts._end  = badAddress;
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    _insts._start   = _insts._end   = badAddress;
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    _stubs._start   = _stubs._end   = badAddress;
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#endif //ASSERT
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  }
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}
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void CodeBuffer::free_blob() {
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  if (_blob != nullptr) {
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    BufferBlob::free(_blob);
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    set_blob(nullptr);
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  }
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}
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const char* CodeBuffer::code_section_name(int n) {
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#ifdef PRODUCT
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  return nullptr;
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#else //PRODUCT
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  switch (n) {
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  case SECT_CONSTS:            return "consts";
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  case SECT_INSTS:             return "insts";
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  case SECT_STUBS:             return "stubs";
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  default:                     return nullptr;
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  }
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#endif //PRODUCT
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}
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int CodeBuffer::section_index_of(address addr) const {
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  for (int n = 0; n < (int)SECT_LIMIT; n++) {
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    const CodeSection* cs = code_section(n);
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    if (cs->allocates(addr))  return n;
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  }
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  return SECT_NONE;
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}
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int CodeBuffer::locator(address addr) const {
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  for (int n = 0; n < (int)SECT_LIMIT; n++) {
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    const CodeSection* cs = code_section(n);
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    if (cs->allocates(addr)) {
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      return locator(addr - cs->start(), n);
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    }
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  }
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  return -1;
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}
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bool CodeBuffer::is_backward_branch(Label& L) {
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  return L.is_bound() && insts_end() <= locator_address(L.loc());
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}
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#ifndef PRODUCT
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address CodeBuffer::decode_begin() {
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  address begin = _insts.start();
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  if (_decode_begin != nullptr && _decode_begin > begin)
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    begin = _decode_begin;
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  return begin;
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}
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#endif // !PRODUCT
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GrowableArray<int>* CodeBuffer::create_patch_overflow() {
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  if (_overflow_arena == nullptr) {
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    _overflow_arena = new (mtCode) Arena(mtCode);
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  }
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  return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
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}
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// Helper function for managing labels and their target addresses.
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// Returns a sensible address, and if it is not the label's final
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// address, notes the dependency (at 'branch_pc') on the label.
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address CodeSection::target(Label& L, address branch_pc) {
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  if (L.is_bound()) {
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    int loc = L.loc();
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    if (index() == CodeBuffer::locator_sect(loc)) {
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      return start() + CodeBuffer::locator_pos(loc);
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    } else {
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      return outer()->locator_address(loc);
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    }
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  } else {
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    assert(allocates2(branch_pc), "sanity");
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    address base = start();
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    int patch_loc = CodeBuffer::locator(branch_pc - base, index());
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    L.add_patch_at(outer(), patch_loc);
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    // Need to return a pc, doesn't matter what it is since it will be
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    // replaced during resolution later.
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    // Don't return null or badAddress, since branches shouldn't overflow.
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    // Don't return base either because that could overflow displacements
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    // for shorter branches.  It will get checked when bound.
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    return branch_pc;
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  }
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}
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void CodeSection::relocate(address at, relocInfo::relocType rtype, int format, jint method_index) {
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  RelocationHolder rh;
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  switch (rtype) {
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    case relocInfo::none: return;
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    case relocInfo::opt_virtual_call_type: {
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      rh = opt_virtual_call_Relocation::spec(method_index);
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      break;
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    }
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    case relocInfo::static_call_type: {
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      rh = static_call_Relocation::spec(method_index);
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      break;
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    }
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    case relocInfo::virtual_call_type: {
294
      assert(method_index == 0, "resolved method overriding is not supported");
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      rh = Relocation::spec_simple(rtype);
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      break;
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    }
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    default: {
299
      rh = Relocation::spec_simple(rtype);
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      break;
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    }
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  }
303
  relocate(at, rh, format);
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}
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void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
307
  // Do not relocate in scratch buffers.
308
  if (scratch_emit()) { return; }
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  Relocation* reloc = spec.reloc();
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  relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
311
  if (rtype == relocInfo::none)  return;
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  // The assertion below has been adjusted, to also work for
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  // relocation for fixup.  Sometimes we want to put relocation
315
  // information for the next instruction, since it will be patched
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  // with a call.
317
  assert(start() <= at && at <= end()+1,
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         "cannot relocate data outside code boundaries");
319

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  if (!has_locs()) {
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    // no space for relocation information provided => code cannot be
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    // relocated.  Make sure that relocate is only called with rtypes
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    // that can be ignored for this kind of code.
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    assert(rtype == relocInfo::none              ||
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           rtype == relocInfo::runtime_call_type ||
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           rtype == relocInfo::internal_word_type||
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           rtype == relocInfo::section_word_type ||
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           rtype == relocInfo::external_word_type||
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           rtype == relocInfo::barrier_type,
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           "code needs relocation information");
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    // leave behind an indication that we attempted a relocation
332
    DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
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    return;
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  }
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  // Advance the point, noting the offset we'll have to record.
337
  csize_t offset = at - locs_point();
338
  set_locs_point(at);
339

340
  // Test for a couple of overflow conditions; maybe expand the buffer.
341
  relocInfo* end = locs_end();
342
  relocInfo* req = end + relocInfo::length_limit;
343
  // Check for (potential) overflow
344
  if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
345
    req += (uint)offset / (uint)relocInfo::offset_limit();
346
    if (req >= locs_limit()) {
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      // Allocate or reallocate.
348
      expand_locs(locs_count() + (req - end));
349
      // reload pointer
350
      end = locs_end();
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    }
352
  }
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354
  // If the offset is giant, emit filler relocs, of type 'none', but
355
  // each carrying the largest possible offset, to advance the locs_point.
356
  while (offset >= relocInfo::offset_limit()) {
357
    assert(end < locs_limit(), "adjust previous paragraph of code");
358
    *end++ = relocInfo::filler_info();
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    offset -= relocInfo::filler_info().addr_offset();
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  }
361

362
  // If it's a simple reloc with no data, we'll just write (rtype | offset).
363
  (*end) = relocInfo(rtype, offset, format);
364

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  // If it has data, insert the prefix, as (data_prefix_tag | data1), data2.
366
  end->initialize(this, reloc);
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}
368

369
void CodeSection::initialize_locs(int locs_capacity) {
370
  assert(_locs_start == nullptr, "only one locs init step, please");
371
  // Apply a priori lower limits to relocation size:
372
  csize_t min_locs = MAX2(size() / 16, (csize_t)4);
373
  if (locs_capacity < min_locs)  locs_capacity = min_locs;
374
  relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity);
375
  _locs_start    = locs_start;
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  _locs_end      = locs_start;
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  _locs_limit    = locs_start + locs_capacity;
378
  _locs_own      = true;
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}
380

381
void CodeSection::initialize_shared_locs(relocInfo* buf, int length) {
382
  assert(_locs_start == nullptr, "do this before locs are allocated");
383
  // Internal invariant:  locs buf must be fully aligned.
384
  // See copy_relocations_to() below.
385
  while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) {
386
    ++buf; --length;
387
  }
388
  if (length > 0) {
389
    _locs_start = buf;
390
    _locs_end   = buf;
391
    _locs_limit = buf + length;
392
    _locs_own   = false;
393
  }
394
}
395

396
void CodeSection::initialize_locs_from(const CodeSection* source_cs) {
397
  int lcount = source_cs->locs_count();
398
  if (lcount != 0) {
399
    initialize_shared_locs(source_cs->locs_start(), lcount);
400
    _locs_end = _locs_limit = _locs_start + lcount;
401
    assert(is_allocated(), "must have copied code already");
402
    set_locs_point(start() + source_cs->locs_point_off());
403
  }
404
  assert(this->locs_count() == source_cs->locs_count(), "sanity");
405
}
406

407
void CodeSection::expand_locs(int new_capacity) {
408
  if (_locs_start == nullptr) {
409
    initialize_locs(new_capacity);
410
    return;
411
  } else {
412
    int old_count    = locs_count();
413
    int old_capacity = locs_capacity();
414
    if (new_capacity < old_capacity * 2)
415
      new_capacity = old_capacity * 2;
416
    relocInfo* locs_start;
417
    if (_locs_own) {
418
      locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity);
419
    } else {
420
      locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity);
421
      Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo));
422
      _locs_own = true;
423
    }
424
    _locs_start    = locs_start;
425
    _locs_end      = locs_start + old_count;
426
    _locs_limit    = locs_start + new_capacity;
427
  }
428
}
429

430
int CodeSection::alignment() const {
431
  if (_index == CodeBuffer::SECT_CONSTS) {
432
    // CodeBuffer controls the alignment of the constants section
433
    return _outer->_const_section_alignment;
434
  }
435
  if (_index == CodeBuffer::SECT_INSTS) {
436
    return (int) CodeEntryAlignment;
437
  }
438
  if (_index == CodeBuffer::SECT_STUBS) {
439
    // CodeBuffer installer expects sections to be HeapWordSize aligned
440
    return HeapWordSize;
441
  }
442
  ShouldNotReachHere();
443
  return 0;
444
}
445

446
/// Support for emitting the code to its final location.
447
/// The pattern is the same for all functions.
448
/// We iterate over all the sections, padding each to alignment.
449

450
csize_t CodeBuffer::total_content_size() const {
451
  csize_t size_so_far = 0;
452
  for (int n = 0; n < (int)SECT_LIMIT; n++) {
453
    const CodeSection* cs = code_section(n);
454
    if (cs->is_empty())  continue;  // skip trivial section
455
    size_so_far = cs->align_at_start(size_so_far);
456
    size_so_far += cs->size();
457
  }
458
  return size_so_far;
459
}
460

461
void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
462
  address buf = dest->_total_start;
463
  csize_t buf_offset = 0;
464
  assert(dest->_total_size >= total_content_size(), "must be big enough");
465
  assert(!_finalize_stubs, "non-finalized stubs");
466

467
  {
468
    // not sure why this is here, but why not...
469
    int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment);
470
    assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment");
471
  }
472

473
  const CodeSection* prev_cs      = nullptr;
474
  CodeSection*       prev_dest_cs = nullptr;
475

476
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
477
    // figure compact layout of each section
478
    const CodeSection* cs = code_section(n);
479
    csize_t csize = cs->size();
480

481
    CodeSection* dest_cs = dest->code_section(n);
482
    if (!cs->is_empty()) {
483
      // Compute initial padding; assign it to the previous non-empty guy.
484
      // Cf. figure_expanded_capacities.
485
      csize_t padding = cs->align_at_start(buf_offset) - buf_offset;
486
      if (prev_dest_cs != nullptr) {
487
        if (padding != 0) {
488
          buf_offset += padding;
489
          prev_dest_cs->_limit += padding;
490
        }
491
      } else {
492
        guarantee(padding == 0, "In first iteration no padding should be needed.");
493
      }
494
      prev_dest_cs = dest_cs;
495
      prev_cs      = cs;
496
    }
497

498
    debug_only(dest_cs->_start = nullptr);  // defeat double-initialization assert
499
    dest_cs->initialize(buf+buf_offset, csize);
500
    dest_cs->set_end(buf+buf_offset+csize);
501
    assert(dest_cs->is_allocated(), "must always be allocated");
502
    assert(cs->is_empty() == dest_cs->is_empty(), "sanity");
503

504
    buf_offset += csize;
505
  }
506

507
  // Done calculating sections; did it come out to the right end?
508
  assert(buf_offset == total_content_size(), "sanity");
509
  debug_only(dest->verify_section_allocation();)
510
}
511

512
// Append an oop reference that keeps the class alive.
513
static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
514
  oop cl = k->klass_holder();
515
  if (cl != nullptr && !oops->contains(cl)) {
516
    oops->append(cl);
517
  }
518
}
519

520
void CodeBuffer::finalize_oop_references(const methodHandle& mh) {
521
  NoSafepointVerifier nsv;
522

523
  GrowableArray<oop> oops;
524

525
  // Make sure that immediate metadata records something in the OopRecorder
526
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
527
    // pull code out of each section
528
    CodeSection* cs = code_section(n);
529
    if (cs->is_empty() || (cs->locs_count() == 0)) continue;  // skip trivial section
530
    RelocIterator iter(cs);
531
    while (iter.next()) {
532
      if (iter.type() == relocInfo::metadata_type) {
533
        metadata_Relocation* md = iter.metadata_reloc();
534
        if (md->metadata_is_immediate()) {
535
          Metadata* m = md->metadata_value();
536
          if (oop_recorder()->is_real(m)) {
537
            if (m->is_methodData()) {
538
              m = ((MethodData*)m)->method();
539
            }
540
            if (m->is_method()) {
541
              m = ((Method*)m)->method_holder();
542
            }
543
            if (m->is_klass()) {
544
              append_oop_references(&oops, (Klass*)m);
545
            } else {
546
              // XXX This will currently occur for MDO which don't
547
              // have a backpointer.  This has to be fixed later.
548
              m->print();
549
              ShouldNotReachHere();
550
            }
551
          }
552
        }
553
      }
554
    }
555
  }
556

557
  if (!oop_recorder()->is_unused()) {
558
    for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
559
      Metadata* m = oop_recorder()->metadata_at(i);
560
      if (oop_recorder()->is_real(m)) {
561
        if (m->is_methodData()) {
562
          m = ((MethodData*)m)->method();
563
        }
564
        if (m->is_method()) {
565
          m = ((Method*)m)->method_holder();
566
        }
567
        if (m->is_klass()) {
568
          append_oop_references(&oops, (Klass*)m);
569
        } else {
570
          m->print();
571
          ShouldNotReachHere();
572
        }
573
      }
574
    }
575

576
  }
577

578
  // Add the class loader of Method* for the nmethod itself
579
  append_oop_references(&oops, mh->method_holder());
580

581
  // Add any oops that we've found
582
  Thread* thread = Thread::current();
583
  for (int i = 0; i < oops.length(); i++) {
584
    oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
585
  }
586
}
587

588

589

590
csize_t CodeBuffer::total_offset_of(const CodeSection* cs) const {
591
  csize_t size_so_far = 0;
592
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
593
    const CodeSection* cur_cs = code_section(n);
594
    if (!cur_cs->is_empty()) {
595
      size_so_far = cur_cs->align_at_start(size_so_far);
596
    }
597
    if (cur_cs->index() == cs->index()) {
598
      return size_so_far;
599
    }
600
    size_so_far += cur_cs->size();
601
  }
602
  ShouldNotReachHere();
603
  return -1;
604
}
605

606
int CodeBuffer::total_skipped_instructions_size() const {
607
  int total_skipped_size = 0;
608
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
609
    const CodeSection* cur_cs = code_section(n);
610
    if (!cur_cs->is_empty()) {
611
      total_skipped_size += cur_cs->_skipped_instructions_size;
612
    }
613
  }
614
  return total_skipped_size;
615
}
616

617
csize_t CodeBuffer::total_relocation_size() const {
618
  csize_t total = copy_relocations_to(nullptr);  // dry run only
619
  return (csize_t) align_up(total, HeapWordSize);
620
}
621

622
csize_t CodeBuffer::copy_relocations_to(address buf, csize_t buf_limit, bool only_inst) const {
623
  csize_t buf_offset = 0;
624
  csize_t code_end_so_far = 0;
625
  csize_t code_point_so_far = 0;
626

627
  assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
628
  assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
629

630
  for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
631
    if (only_inst && (n != (int)SECT_INSTS)) {
632
      // Need only relocation info for code.
633
      continue;
634
    }
635
    // pull relocs out of each section
636
    const CodeSection* cs = code_section(n);
637
    assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
638
    if (cs->is_empty())  continue;  // skip trivial section
639
    relocInfo* lstart = cs->locs_start();
640
    relocInfo* lend   = cs->locs_end();
641
    csize_t    lsize  = (csize_t)( (address)lend - (address)lstart );
642
    csize_t    csize  = cs->size();
643
    code_end_so_far = cs->align_at_start(code_end_so_far);
644

645
    if (lsize > 0) {
646
      // Figure out how to advance the combined relocation point
647
      // first to the beginning of this section.
648
      // We'll insert one or more filler relocs to span that gap.
649
      // (Don't bother to improve this by editing the first reloc's offset.)
650
      csize_t new_code_point = code_end_so_far;
651
      for (csize_t jump;
652
           code_point_so_far < new_code_point;
653
           code_point_so_far += jump) {
654
        jump = new_code_point - code_point_so_far;
655
        relocInfo filler = relocInfo::filler_info();
656
        if (jump >= filler.addr_offset()) {
657
          jump = filler.addr_offset();
658
        } else {  // else shrink the filler to fit
659
          filler = relocInfo(relocInfo::none, jump);
660
        }
661
        if (buf != nullptr) {
662
          assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
663
          *(relocInfo*)(buf+buf_offset) = filler;
664
        }
665
        buf_offset += sizeof(filler);
666
      }
667

668
      // Update code point and end to skip past this section:
669
      csize_t last_code_point = code_end_so_far + cs->locs_point_off();
670
      assert(code_point_so_far <= last_code_point, "sanity");
671
      code_point_so_far = last_code_point; // advance past this guy's relocs
672
    }
673
    code_end_so_far += csize;  // advance past this guy's instructions too
674

675
    // Done with filler; emit the real relocations:
676
    if (buf != nullptr && lsize != 0) {
677
      assert(buf_offset + lsize <= buf_limit, "target in bounds");
678
      assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
679
      if (buf_offset % HeapWordSize == 0) {
680
        // Use wordwise copies if possible:
681
        Copy::disjoint_words((HeapWord*)lstart,
682
                             (HeapWord*)(buf+buf_offset),
683
                             (lsize + HeapWordSize-1) / HeapWordSize);
684
      } else {
685
        Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
686
      }
687
    }
688
    buf_offset += lsize;
689
  }
690

691
  // Align end of relocation info in target.
692
  while (buf_offset % HeapWordSize != 0) {
693
    if (buf != nullptr) {
694
      relocInfo padding = relocInfo(relocInfo::none, 0);
695
      assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
696
      *(relocInfo*)(buf+buf_offset) = padding;
697
    }
698
    buf_offset += sizeof(relocInfo);
699
  }
700

701
  assert(only_inst || code_end_so_far == total_content_size(), "sanity");
702

703
  return buf_offset;
704
}
705

706
csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
707
  address buf = nullptr;
708
  csize_t buf_offset = 0;
709
  csize_t buf_limit = 0;
710

711
  if (dest != nullptr) {
712
    buf = (address)dest->relocation_begin();
713
    buf_limit = (address)dest->relocation_end() - buf;
714
  }
715
  // if dest is null, this is just the sizing pass
716
  //
717
  buf_offset = copy_relocations_to(buf, buf_limit, false);
718

719
  return buf_offset;
720
}
721

722
void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
723
#ifndef PRODUCT
724
  if (PrintNMethods && (WizardMode || Verbose)) {
725
    tty->print("done with CodeBuffer:");
726
    ((CodeBuffer*)this)->print();
727
  }
728
#endif //PRODUCT
729

730
  CodeBuffer dest(dest_blob);
731
  assert(dest_blob->content_size() >= total_content_size(), "good sizing");
732
  this->compute_final_layout(&dest);
733

734
  // Set beginning of constant table before relocating.
735
  dest_blob->set_ctable_begin(dest.consts()->start());
736

737
  relocate_code_to(&dest);
738

739
  // Share assembly remarks and debug strings with the blob.
740
  NOT_PRODUCT(dest_blob->use_remarks(_asm_remarks));
741
  NOT_PRODUCT(dest_blob->use_strings(_dbg_strings));
742

743
  // Done moving code bytes; were they the right size?
744
  assert((int)align_up(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
745

746
  // Flush generated code
747
  ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
748
}
749

750
// Move all my code into another code buffer.  Consult applicable
751
// relocs to repair embedded addresses.  The layout in the destination
752
// CodeBuffer is different to the source CodeBuffer: the destination
753
// CodeBuffer gets the final layout (consts, insts, stubs in order of
754
// ascending address).
755
void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
756
  address dest_end = dest->_total_start + dest->_total_size;
757
  address dest_filled = nullptr;
758
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
759
    // pull code out of each section
760
    const CodeSection* cs = code_section(n);
761
    if (cs->is_empty())  continue;  // skip trivial section
762
    CodeSection* dest_cs = dest->code_section(n);
763
    assert(cs->size() == dest_cs->size(), "sanity");
764
    csize_t usize = dest_cs->size();
765
    csize_t wsize = align_up(usize, HeapWordSize);
766
    assert(dest_cs->start() + wsize <= dest_end, "no overflow");
767
    // Copy the code as aligned machine words.
768
    // This may also include an uninitialized partial word at the end.
769
    Copy::disjoint_words((HeapWord*)cs->start(),
770
                         (HeapWord*)dest_cs->start(),
771
                         wsize / HeapWordSize);
772

773
    if (dest->blob() == nullptr) {
774
      // Destination is a final resting place, not just another buffer.
775
      // Normalize uninitialized bytes in the final padding.
776
      Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
777
                          Assembler::code_fill_byte());
778
    }
779
    // Keep track of the highest filled address
780
    dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
781

782
    assert(cs->locs_start() != (relocInfo*)badAddress,
783
           "this section carries no reloc storage, but reloc was attempted");
784

785
    // Make the new code copy use the old copy's relocations:
786
    dest_cs->initialize_locs_from(cs);
787
  }
788

789
  // Do relocation after all sections are copied.
790
  // This is necessary if the code uses constants in stubs, which are
791
  // relocated when the corresponding instruction in the code (e.g., a
792
  // call) is relocated. Stubs are placed behind the main code
793
  // section, so that section has to be copied before relocating.
794
  for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
795
    CodeSection* dest_cs = dest->code_section(n);
796
    if (dest_cs->is_empty() || (dest_cs->locs_count() == 0)) continue;  // skip trivial section
797
    { // Repair the pc relative information in the code after the move
798
      RelocIterator iter(dest_cs);
799
      while (iter.next()) {
800
        iter.reloc()->fix_relocation_after_move(this, dest);
801
      }
802
    }
803
  }
804

805
  if (dest->blob() == nullptr && dest_filled != nullptr) {
806
    // Destination is a final resting place, not just another buffer.
807
    // Normalize uninitialized bytes in the final padding.
808
    Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
809
                        Assembler::code_fill_byte());
810

811
  }
812
}
813

814
csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
815
                                               csize_t amount,
816
                                               csize_t* new_capacity) {
817
  csize_t new_total_cap = 0;
818

819
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
820
    const CodeSection* sect = code_section(n);
821

822
    if (!sect->is_empty()) {
823
      // Compute initial padding; assign it to the previous section,
824
      // even if it's empty (e.g. consts section can be empty).
825
      // Cf. compute_final_layout
826
      csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
827
      if (padding != 0) {
828
        new_total_cap += padding;
829
        assert(n - 1 >= SECT_FIRST, "sanity");
830
        new_capacity[n - 1] += padding;
831
      }
832
    }
833

834
    csize_t exp = sect->size();  // 100% increase
835
    if ((uint)exp < 4*K)  exp = 4*K;       // minimum initial increase
836
    if (sect == which_cs) {
837
      if (exp < amount)  exp = amount;
838
      if (StressCodeBuffers)  exp = amount;  // expand only slightly
839
    } else if (n == SECT_INSTS) {
840
      // scale down inst increases to a more modest 25%
841
      exp = 4*K + ((exp - 4*K) >> 2);
842
      if (StressCodeBuffers)  exp = amount / 2;  // expand only slightly
843
    } else if (sect->is_empty()) {
844
      // do not grow an empty secondary section
845
      exp = 0;
846
    }
847
    // Allow for inter-section slop:
848
    exp += CodeSection::end_slop();
849
    csize_t new_cap = sect->size() + exp;
850
    if (new_cap < sect->capacity()) {
851
      // No need to expand after all.
852
      new_cap = sect->capacity();
853
    }
854
    new_capacity[n] = new_cap;
855
    new_total_cap += new_cap;
856
  }
857

858
  return new_total_cap;
859
}
860

861
void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
862
#ifndef PRODUCT
863
  if (PrintNMethods && (WizardMode || Verbose)) {
864
    tty->print("expanding CodeBuffer:");
865
    this->print();
866
  }
867

868
  if (StressCodeBuffers && blob() != nullptr) {
869
    static int expand_count = 0;
870
    if (expand_count >= 0)  expand_count += 1;
871
    if (expand_count > 100 && is_power_of_2(expand_count)) {
872
      tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
873
      // simulate an occasional allocation failure:
874
      free_blob();
875
    }
876
  }
877
#endif //PRODUCT
878

879
  // Resizing must be allowed
880
  {
881
    if (blob() == nullptr)  return;  // caller must check if blob is null
882
  }
883

884
  // Figure new capacity for each section.
885
  csize_t new_capacity[SECT_LIMIT];
886
  memset(new_capacity, 0, sizeof(csize_t) * SECT_LIMIT);
887
  csize_t new_total_cap
888
    = figure_expanded_capacities(which_cs, amount, new_capacity);
889

890
  // Create a new (temporary) code buffer to hold all the new data
891
  CodeBuffer cb(name(), new_total_cap, 0);
892
  if (cb.blob() == nullptr) {
893
    // Failed to allocate in code cache.
894
    free_blob();
895
    return;
896
  }
897

898
  // Create an old code buffer to remember which addresses used to go where.
899
  // This will be useful when we do final assembly into the code cache,
900
  // because we will need to know how to warp any internal address that
901
  // has been created at any time in this CodeBuffer's past.
902
  CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
903
  bxp->take_over_code_from(this);  // remember the old undersized blob
904
  DEBUG_ONLY(this->_blob = nullptr);  // silence a later assert
905
  bxp->_before_expand = this->_before_expand;
906
  this->_before_expand = bxp;
907

908
  // Give each section its required (expanded) capacity.
909
  for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
910
    CodeSection* cb_sect   = cb.code_section(n);
911
    CodeSection* this_sect = code_section(n);
912
    if (new_capacity[n] == 0)  continue;  // already nulled out
913
    if (n != SECT_INSTS) {
914
      cb.initialize_section_size(cb_sect, new_capacity[n]);
915
    }
916
    assert(cb_sect->capacity() >= new_capacity[n], "big enough");
917
    address cb_start = cb_sect->start();
918
    cb_sect->set_end(cb_start + this_sect->size());
919
    if (this_sect->mark() == nullptr) {
920
      cb_sect->clear_mark();
921
    } else {
922
      cb_sect->set_mark(cb_start + this_sect->mark_off());
923
    }
924
  }
925

926
  // Needs to be initialized when calling fix_relocation_after_move.
927
  cb.blob()->set_ctable_begin(cb.consts()->start());
928

929
  // Move all the code and relocations to the new blob:
930
  relocate_code_to(&cb);
931

932
  // some internal addresses, _last_insn _last_label, are used during code emission,
933
  // adjust them in expansion
934
  adjust_internal_address(insts_begin(), cb.insts_begin());
935

936
  // Copy the temporary code buffer into the current code buffer.
937
  // Basically, do {*this = cb}, except for some control information.
938
  this->take_over_code_from(&cb);
939
  cb.set_blob(nullptr);
940

941
  // Zap the old code buffer contents, to avoid mistakenly using them.
942
  debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
943
                                 badCodeHeapFreeVal);)
944

945
  // Make certain that the new sections are all snugly inside the new blob.
946
  debug_only(verify_section_allocation();)
947

948
#ifndef PRODUCT
949
  _decode_begin = nullptr;  // sanity
950
  if (PrintNMethods && (WizardMode || Verbose)) {
951
    tty->print("expanded CodeBuffer:");
952
    this->print();
953
  }
954
#endif //PRODUCT
955
}
956

957
void CodeBuffer::adjust_internal_address(address from, address to) {
958
  if (_last_insn != nullptr) {
959
    _last_insn += to - from;
960
  }
961
  if (_last_label != nullptr) {
962
    _last_label += to - from;
963
  }
964
}
965

966
void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
967
  // Must already have disposed of the old blob somehow.
968
  assert(blob() == nullptr, "must be empty");
969
  // Take the new blob away from cb.
970
  set_blob(cb->blob());
971
  // Take over all the section pointers.
972
  for (int n = 0; n < (int)SECT_LIMIT; n++) {
973
    CodeSection* cb_sect   = cb->code_section(n);
974
    CodeSection* this_sect = code_section(n);
975
    this_sect->take_over_code_from(cb_sect);
976
  }
977
  // Make sure the old cb won't try to use it or free it.
978
  DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
979
}
980

981
void CodeBuffer::verify_section_allocation() {
982
  address tstart = _total_start;
983
  if (tstart == badAddress)  return;  // smashed by set_blob(nullptr)
984
  address tend   = tstart + _total_size;
985
  if (_blob != nullptr) {
986
    guarantee(tstart >= _blob->content_begin(), "sanity");
987
    guarantee(tend   <= _blob->content_end(),   "sanity");
988
  }
989
  // Verify disjointness.
990
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
991
    CodeSection* sect = code_section(n);
992
    if (!sect->is_allocated() || sect->is_empty()) {
993
      continue;
994
    }
995
    guarantee(_blob == nullptr || is_aligned(sect->start(), sect->alignment()),
996
           "start is aligned");
997
    for (int m = n + 1; m < (int) SECT_LIMIT; m++) {
998
      CodeSection* other = code_section(m);
999
      if (!other->is_allocated() || other == sect) {
1000
        continue;
1001
      }
1002
      guarantee(other->disjoint(sect), "sanity");
1003
    }
1004
    guarantee(sect->end() <= tend, "sanity");
1005
    guarantee(sect->end() <= sect->limit(), "sanity");
1006
  }
1007
}
1008

1009
void CodeBuffer::log_section_sizes(const char* name) {
1010
  if (xtty != nullptr) {
1011
    ttyLocker ttyl;
1012
    // log info about buffer usage
1013
    xtty->print_cr("<blob name='%s' total_size='%d'>", name, _total_size);
1014
    for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
1015
      CodeSection* sect = code_section(n);
1016
      if (!sect->is_allocated() || sect->is_empty())  continue;
1017
      xtty->print_cr("<sect index='%d' capacity='%d' size='%d' remaining='%d'/>",
1018
                     n, sect->capacity(), sect->size(), sect->remaining());
1019
    }
1020
    xtty->print_cr("</blob>");
1021
  }
1022
}
1023

1024
bool CodeBuffer::finalize_stubs() {
1025
  if (_finalize_stubs && !pd_finalize_stubs()) {
1026
    // stub allocation failure
1027
    return false;
1028
  }
1029
  _finalize_stubs = false;
1030
  return true;
1031
}
1032

1033
void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset) {
1034
  if (_shared_stub_to_interp_requests == nullptr) {
1035
    _shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
1036
  }
1037
  SharedStubToInterpRequest request(callee, call_offset);
1038
  _shared_stub_to_interp_requests->push(request);
1039
  _finalize_stubs = true;
1040
}
1041

1042
#ifndef PRODUCT
1043
void CodeBuffer::block_comment(ptrdiff_t offset, const char* comment) {
1044
  if (_collect_comments) {
1045
    const char* str = _asm_remarks.insert(offset, comment);
1046
    postcond(str != comment);
1047
  }
1048
}
1049

1050
const char* CodeBuffer::code_string(const char* str) {
1051
  const char* tmp = _dbg_strings.insert(str);
1052
  postcond(tmp != str);
1053
  return tmp;
1054
}
1055

1056
void CodeBuffer::decode() {
1057
  ttyLocker ttyl;
1058
  Disassembler::decode(decode_begin(), insts_end(), tty NOT_PRODUCT(COMMA &asm_remarks()));
1059
  _decode_begin = insts_end();
1060
}
1061

1062
void CodeSection::print(const char* name) {
1063
  csize_t locs_size = locs_end() - locs_start();
1064
  tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)",
1065
                name, p2i(start()), p2i(end()), p2i(limit()), size(), capacity());
1066
  tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1067
                name, p2i(locs_start()), p2i(locs_end()), p2i(locs_limit()), locs_size, locs_capacity(), locs_point_off());
1068
  if (PrintRelocations && (locs_size != 0)) {
1069
    RelocIterator iter(this);
1070
    iter.print();
1071
  }
1072
}
1073

1074
void CodeBuffer::print() {
1075
  tty->print_cr("CodeBuffer:");
1076
  for (int n = 0; n < (int)SECT_LIMIT; n++) {
1077
    // print each section
1078
    CodeSection* cs = code_section(n);
1079
    cs->print(code_section_name(n));
1080
  }
1081
}
1082

1083
// ----- CHeapString -----------------------------------------------------------
1084

1085
class CHeapString : public CHeapObj<mtCode> {
1086
 public:
1087
  CHeapString(const char* str) : _string(os::strdup(str)) {}
1088
 ~CHeapString() {
1089
    os::free((void*)_string);
1090
    _string = nullptr;
1091
  }
1092
  const char* string() const { return _string; }
1093

1094
 private:
1095
  const char* _string;
1096
};
1097

1098
// ----- AsmRemarkCollection ---------------------------------------------------
1099

1100
class AsmRemarkCollection : public CHeapObj<mtCode> {
1101
 public:
1102
  AsmRemarkCollection() : _ref_cnt(1), _remarks(nullptr), _next(nullptr) {}
1103
 ~AsmRemarkCollection() {
1104
    assert(is_empty(), "Must 'clear()' before deleting!");
1105
    assert(_ref_cnt == 0, "No uses must remain when deleting!");
1106
  }
1107
  AsmRemarkCollection* reuse() {
1108
    precond(_ref_cnt > 0);
1109
    return _ref_cnt++, this;
1110
  }
1111

1112
  const char* insert(uint offset, const char* remark);
1113
  const char* lookup(uint offset) const;
1114
  const char* next(uint offset) const;
1115

1116
  bool is_empty() const { return _remarks == nullptr; }
1117
  uint clear();
1118

1119
 private:
1120
  struct Cell : CHeapString {
1121
    Cell(const char* remark, uint offset) :
1122
        CHeapString(remark), offset(offset), prev(nullptr), next(nullptr) {}
1123
    void push_back(Cell* cell) {
1124
      Cell* head = this;
1125
      Cell* tail = prev;
1126
      tail->next = cell;
1127
      cell->next = head;
1128
      cell->prev = tail;
1129
      prev = cell;
1130
    }
1131
    uint offset;
1132
    Cell* prev;
1133
    Cell* next;
1134
  };
1135
  uint  _ref_cnt;
1136
  Cell* _remarks;
1137
  // Using a 'mutable' iteration pointer to allow 'const' on lookup/next (that
1138
  // does not change the state of the list per se), supportig a simplistic
1139
  // iteration scheme.
1140
  mutable Cell* _next;
1141
};
1142

1143
// ----- DbgStringCollection ---------------------------------------------------
1144

1145
class DbgStringCollection : public CHeapObj<mtCode> {
1146
 public:
1147
  DbgStringCollection() : _ref_cnt(1), _strings(nullptr) {}
1148
 ~DbgStringCollection() {
1149
    assert(is_empty(), "Must 'clear()' before deleting!");
1150
    assert(_ref_cnt == 0, "No uses must remain when deleting!");
1151
  }
1152
  DbgStringCollection* reuse() {
1153
    precond(_ref_cnt > 0);
1154
    return _ref_cnt++, this;
1155
  }
1156

1157
  const char* insert(const char* str);
1158
  const char* lookup(const char* str) const;
1159

1160
  bool is_empty() const { return _strings == nullptr; }
1161
  uint clear();
1162

1163
 private:
1164
  struct Cell : CHeapString {
1165
    Cell(const char* dbgstr) :
1166
        CHeapString(dbgstr), prev(nullptr), next(nullptr) {}
1167
    void push_back(Cell* cell) {
1168
      Cell* head = this;
1169
      Cell* tail = prev;
1170
      tail->next = cell;
1171
      cell->next = head;
1172
      cell->prev = tail;
1173
      prev = cell;
1174
    }
1175
    Cell* prev;
1176
    Cell* next;
1177
  };
1178
  uint  _ref_cnt;
1179
  Cell* _strings;
1180
};
1181

1182
// ----- AsmRemarks ------------------------------------------------------------
1183
//
1184
// Acting as interface to reference counted mapping [offset -> remark], where
1185
// offset is a byte offset into an instruction stream (CodeBuffer, CodeBlob or
1186
// other memory buffer) and remark is a string (comment).
1187
//
1188
AsmRemarks::AsmRemarks() : _remarks(new AsmRemarkCollection()) {
1189
  assert(_remarks != nullptr, "Allocation failure!");
1190
}
1191

1192
AsmRemarks::~AsmRemarks() {
1193
  assert(_remarks == nullptr, "Must 'clear()' before deleting!");
1194
}
1195

1196
const char* AsmRemarks::insert(uint offset, const char* remstr) {
1197
  precond(remstr != nullptr);
1198
  return _remarks->insert(offset, remstr);
1199
}
1200

1201
bool AsmRemarks::is_empty() const {
1202
  return _remarks->is_empty();
1203
}
1204

1205
void AsmRemarks::share(const AsmRemarks &src) {
1206
  precond(is_empty());
1207
  clear();
1208
  _remarks = src._remarks->reuse();
1209
}
1210

1211
void AsmRemarks::clear() {
1212
  if (_remarks->clear() == 0) {
1213
    delete _remarks;
1214
  }
1215
  _remarks = nullptr;
1216
}
1217

1218
uint AsmRemarks::print(uint offset, outputStream* strm) const {
1219
  uint count = 0;
1220
  const char* prefix = " ;; ";
1221
  const char* remstr = _remarks->lookup(offset);
1222
  while (remstr != nullptr) {
1223
    strm->bol();
1224
    strm->print("%s", prefix);
1225
    // Don't interpret as format strings since it could contain '%'.
1226
    strm->print_raw(remstr);
1227
    // Advance to next line iff string didn't contain a cr() at the end.
1228
    strm->bol();
1229
    remstr = _remarks->next(offset);
1230
    count++;
1231
  }
1232
  return count;
1233
}
1234

1235
// ----- DbgStrings ------------------------------------------------------------
1236
//
1237
// Acting as interface to reference counted collection of (debug) strings used
1238
// in the code generated, and thus requiring a fixed address.
1239
//
1240
DbgStrings::DbgStrings() : _strings(new DbgStringCollection()) {
1241
  assert(_strings != nullptr, "Allocation failure!");
1242
}
1243

1244
DbgStrings::~DbgStrings() {
1245
  assert(_strings == nullptr, "Must 'clear()' before deleting!");
1246
}
1247

1248
const char* DbgStrings::insert(const char* dbgstr) {
1249
  const char* str = _strings->lookup(dbgstr);
1250
  return str != nullptr ? str : _strings->insert(dbgstr);
1251
}
1252

1253
bool DbgStrings::is_empty() const {
1254
  return _strings->is_empty();
1255
}
1256

1257
void DbgStrings::share(const DbgStrings &src) {
1258
  precond(is_empty());
1259
  clear();
1260
  _strings = src._strings->reuse();
1261
}
1262

1263
void DbgStrings::clear() {
1264
  if (_strings->clear() == 0) {
1265
    delete _strings;
1266
  }
1267
  _strings = nullptr;
1268
}
1269

1270
// ----- AsmRemarkCollection ---------------------------------------------------
1271

1272
const char* AsmRemarkCollection::insert(uint offset, const char* remstr) {
1273
  precond(remstr != nullptr);
1274
  Cell* cell = new Cell { remstr, offset };
1275
  if (is_empty()) {
1276
    cell->prev = cell;
1277
    cell->next = cell;
1278
    _remarks = cell;
1279
  } else {
1280
    _remarks->push_back(cell);
1281
  }
1282
  return cell->string();
1283
}
1284

1285
const char* AsmRemarkCollection::lookup(uint offset) const {
1286
  _next = _remarks;
1287
  return next(offset);
1288
}
1289

1290
const char* AsmRemarkCollection::next(uint offset) const {
1291
  if (_next != nullptr) {
1292
    Cell* i = _next;
1293
    do {
1294
      if (i->offset == offset) {
1295
        _next = i->next == _remarks ? nullptr : i->next;
1296
        return i->string();
1297
      }
1298
      i = i->next;
1299
    } while (i != _remarks);
1300
    _next = nullptr;
1301
  }
1302
  return nullptr;
1303
}
1304

1305
uint AsmRemarkCollection::clear() {
1306
  precond(_ref_cnt > 0);
1307
  if (--_ref_cnt > 0) {
1308
    return _ref_cnt;
1309
  }
1310
  if (!is_empty()) {
1311
    uint count = 0;
1312
    Cell* i = _remarks;
1313
    do {
1314
      Cell* next = i->next;
1315
      delete i;
1316
      i = next;
1317
      count++;
1318
    } while (i != _remarks);
1319

1320
    log_debug(codestrings)("Clear %u asm-remark%s.", count, count == 1 ? "" : "s");
1321
    _remarks = nullptr;
1322
  }
1323
  return 0; // i.e. _ref_cnt == 0
1324
}
1325

1326
// ----- DbgStringCollection ---------------------------------------------------
1327

1328
const char* DbgStringCollection::insert(const char* dbgstr) {
1329
  precond(dbgstr != nullptr);
1330
  Cell* cell = new Cell { dbgstr };
1331

1332
  if (is_empty()) {
1333
     cell->prev = cell;
1334
     cell->next = cell;
1335
     _strings = cell;
1336
  } else {
1337
    _strings->push_back(cell);
1338
  }
1339
  return cell->string();
1340
}
1341

1342
const char* DbgStringCollection::lookup(const char* dbgstr) const {
1343
  precond(dbgstr != nullptr);
1344
  if (_strings != nullptr) {
1345
    Cell* i = _strings;
1346
    do {
1347
      if (strcmp(i->string(), dbgstr) == 0) {
1348
        return i->string();
1349
      }
1350
      i = i->next;
1351
    } while (i != _strings);
1352
  }
1353
  return nullptr;
1354
}
1355

1356
uint DbgStringCollection::clear() {
1357
  precond(_ref_cnt > 0);
1358
  if (--_ref_cnt > 0) {
1359
    return _ref_cnt;
1360
  }
1361
  if (!is_empty()) {
1362
    uint count = 0;
1363
    Cell* i = _strings;
1364
    do {
1365
      Cell* next = i->next;
1366
      delete i;
1367
      i = next;
1368
      count++;
1369
    } while (i != _strings);
1370

1371
    log_debug(codestrings)("Clear %u dbg-string%s.", count, count == 1 ? "" : "s");
1372
    _strings = nullptr;
1373
  }
1374
  return 0; // i.e. _ref_cnt == 0
1375
}
1376

1377
#endif // not PRODUCT
1378