src/hotspot/share/compiler/compilerOracle.cpp

/*
 * Copyright (c) 1998, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "classfile/symbolTable.hpp"
#include "compiler/compilerDirectives.hpp"
#include "compiler/compilerOracle.hpp"
#include "compiler/methodMatcher.hpp"
#include "jvm.h"
#include "memory/allocation.inline.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "oops/klass.hpp"
#include "oops/method.inline.hpp"
#include "oops/symbol.hpp"
#include "opto/phasetype.hpp"
#include "opto/traceAutoVectorizationTag.hpp"
#include "opto/traceMergeStoresTag.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/jniHandles.hpp"
#include "runtime/os.hpp"
#include "utilities/istream.hpp"
#include "utilities/parseInteger.hpp"

// Default compile commands, if defined, are parsed before any of the
// explicitly defined compile commands. Thus, explicitly defined compile
// commands take precedence over default compile commands. The effect is
// as if the default compile commands had been specified at the start of
// the command line.
static const char* const default_compile_commands[] = {
#ifdef ASSERT
    // In debug builds, impose a (generous) per-compilation memory limit
    // to catch pathological compilations during testing. The suboption
    // "crash" will cause the JVM to assert.
    //
    // Note: to disable the default limit at the command line,
    // set a limit of 0 (e.g. -XX:CompileCommand=MemLimit,*.*,0).
    "MemLimit,*.*,1G~crash",
#endif
    nullptr };

static const char* optiontype_names[] = {
#define enum_of_types(type, name) name,
        OPTION_TYPES(enum_of_types)
#undef enum_of_types
};

static const char* optiontype2name(enum OptionType type) {
  return optiontype_names[static_cast<int>(type)];
}

static enum OptionType option_types[] = {
#define enum_of_options(option, name, ctype) OptionType::ctype,
        COMPILECOMMAND_OPTIONS(enum_of_options)
#undef enum_of_options
};

static enum OptionType option2type(CompileCommandEnum option) {
  return option_types[static_cast<int>(option)];
}

static const char* option_names[] = {
#define enum_of_options(option, name, ctype) name,
        COMPILECOMMAND_OPTIONS(enum_of_options)
#undef enum_of_options
};

static const char* option2name(CompileCommandEnum option) {
  return option_names[static_cast<int>(option)];
}

/* Methods to map real type names to OptionType */
template<typename T>
static OptionType get_type_for() {
  return OptionType::Unknown;
};

template<> OptionType get_type_for<intx>() {
  return OptionType::Intx;
}

template<> OptionType get_type_for<uintx>() {
  return OptionType::Uintx;
}

template<> OptionType get_type_for<bool>() {
  return OptionType::Bool;
}

template<> OptionType get_type_for<ccstr>() {
  return OptionType::Ccstr;
}

template<> OptionType get_type_for<double>() {
  return OptionType::Double;
}

class MethodMatcher;
class TypedMethodOptionMatcher;

static TypedMethodOptionMatcher* option_list = nullptr;
static bool any_set = false;

// A filter for quick lookup if an option is set
static bool option_filter[static_cast<int>(CompileCommandEnum::Unknown) + 1] = { 0 };

static void command_set_in_filter(CompileCommandEnum option) {
  assert(option != CompileCommandEnum::Unknown, "sanity");
  assert(option2type(option) != OptionType::Unknown, "sanity");

  if ((option != CompileCommandEnum::DontInline) &&
      (option != CompileCommandEnum::Inline) &&
      (option != CompileCommandEnum::Log)) {
    any_set = true;
  }
  option_filter[static_cast<int>(option)] = true;
}

static bool has_command(CompileCommandEnum option) {
  return option_filter[static_cast<int>(option)];
}

class TypedMethodOptionMatcher : public MethodMatcher {
 private:
  TypedMethodOptionMatcher* _next;
  CompileCommandEnum _option;
 public:

  union {
    bool bool_value;
    intx intx_value;
    uintx uintx_value;
    double double_value;
    ccstr ccstr_value;
  } _u;

  TypedMethodOptionMatcher() : MethodMatcher(),
    _next(nullptr),
    _option(CompileCommandEnum::Unknown) {
      memset(&_u, 0, sizeof(_u));
  }

  ~TypedMethodOptionMatcher();
  static TypedMethodOptionMatcher* parse_method_pattern(char*& line, char* errorbuf, const int buf_size);
  TypedMethodOptionMatcher* match(const methodHandle &method, CompileCommandEnum option);

  void init(CompileCommandEnum option, TypedMethodOptionMatcher* next) {
    _next = next;
    _option = option;
  }

  void init_matcher(Symbol* class_name, Mode class_mode,
                    Symbol* method_name, Mode method_mode,
                    Symbol* signature) {
    MethodMatcher::init(class_name, class_mode, method_name, method_mode, signature);
  }

  void set_next(TypedMethodOptionMatcher* next) {_next = next; }
  TypedMethodOptionMatcher* next() { return _next; }
  CompileCommandEnum option() { return _option; }
  template<typename T> T value();
  template<typename T> void set_value(T value);
  void print();
  void print_all();
  TypedMethodOptionMatcher* clone();
};

// A few templated accessors instead of a full template class.
template<> intx TypedMethodOptionMatcher::value<intx>() {
  return _u.intx_value;
}

template<> uintx TypedMethodOptionMatcher::value<uintx>() {
  return _u.uintx_value;
}

template<> bool TypedMethodOptionMatcher::value<bool>() {
  return _u.bool_value;
}

template<> double TypedMethodOptionMatcher::value<double>() {
  return _u.double_value;
}

template<> ccstr TypedMethodOptionMatcher::value<ccstr>() {
  return _u.ccstr_value;
}

template<> void TypedMethodOptionMatcher::set_value(intx value) {
  _u.intx_value = value;
}

template<> void TypedMethodOptionMatcher::set_value(uintx value) {
  _u.uintx_value = value;
}

template<> void TypedMethodOptionMatcher::set_value(double value) {
  _u.double_value = value;
}

template<> void TypedMethodOptionMatcher::set_value(bool value) {
  _u.bool_value = value;
}

template<> void TypedMethodOptionMatcher::set_value(ccstr value) {
  _u.ccstr_value = (ccstr)os::strdup_check_oom(value);
}

void TypedMethodOptionMatcher::print() {
  ttyLocker ttyl;
  print_base(tty);
  const char* name = option2name(_option);
  enum OptionType type = option2type(_option);
  switch (type) {
    case OptionType::Intx:
    tty->print_cr(" intx %s = %zd", name, value<intx>());
    break;
    case OptionType::Uintx:
    tty->print_cr(" uintx %s = %zu", name, value<uintx>());
    break;
    case OptionType::Bool:
    tty->print_cr(" bool %s = %s", name, value<bool>() ? "true" : "false");
    break;
    case OptionType::Double:
    tty->print_cr(" double %s = %f", name, value<double>());
    break;
    case OptionType::Ccstr:
    case OptionType::Ccstrlist:
    tty->print_cr(" const char* %s = '%s'", name, value<ccstr>());
    break;
  default:
    ShouldNotReachHere();
  }
}

void TypedMethodOptionMatcher::print_all() {
   print();
   if (_next != nullptr) {
     tty->print(" ");
     _next->print_all();
   }
 }

TypedMethodOptionMatcher* TypedMethodOptionMatcher::clone() {
  TypedMethodOptionMatcher* m = new TypedMethodOptionMatcher();
  m->_class_mode = _class_mode;
  m->_class_name = _class_name;
  m->_method_mode = _method_mode;
  m->_method_name = _method_name;
  m->_signature = _signature;
  // Need to ref count the symbols
  if (_class_name != nullptr) {
    _class_name->increment_refcount();
  }
  if (_method_name != nullptr) {
    _method_name->increment_refcount();
  }
  if (_signature != nullptr) {
    _signature->increment_refcount();
  }
  return m;
}

TypedMethodOptionMatcher::~TypedMethodOptionMatcher() {
  enum OptionType type = option2type(_option);
  if (type == OptionType::Ccstr || type == OptionType::Ccstrlist) {
    ccstr v = value<ccstr>();
    os::free((void*)v);
  }
}

TypedMethodOptionMatcher* TypedMethodOptionMatcher::parse_method_pattern(char*& line, char* errorbuf, const int buf_size) {
  assert(*errorbuf == '\0', "Dont call here with error_msg already set");
  const char* error_msg = nullptr;
  TypedMethodOptionMatcher* tom = new TypedMethodOptionMatcher();
  MethodMatcher::parse_method_pattern(line, error_msg, tom);
  if (error_msg != nullptr) {
    jio_snprintf(errorbuf, buf_size, error_msg);
    delete tom;
    return nullptr;
  }
  return tom;
}

TypedMethodOptionMatcher* TypedMethodOptionMatcher::match(const methodHandle& method, CompileCommandEnum option) {
  TypedMethodOptionMatcher* current = this;
  while (current != nullptr) {
    if (current->_option == option) {
      if (current->matches(method)) {
        return current;
      }
    }
    current = current->next();
  }
  return nullptr;
}

template<typename T>
static bool register_command(TypedMethodOptionMatcher* matcher,
                             CompileCommandEnum option,
                             char* errorbuf,
                             const int buf_size,
                             T value) {
  assert(matcher != option_list, "No circular lists please");
  if (option == CompileCommandEnum::Log && !LogCompilation) {
    tty->print_cr("Warning:  +LogCompilation must be enabled in order for individual methods to be logged with ");
    tty->print_cr("          CompileCommand=log,<method pattern>");
  }
  assert(CompilerOracle::option_matches_type(option, value), "Value must match option type");

  if (option == CompileCommandEnum::Blackhole && !UnlockExperimentalVMOptions) {
    warning("Blackhole compile option is experimental and must be enabled via -XX:+UnlockExperimentalVMOptions");
    // Delete matcher as we don't keep it
    delete matcher;
    return true;
  }

  if (!UnlockDiagnosticVMOptions) {
    const char* name = option2name(option);
    JVMFlag* flag = JVMFlag::find_declared_flag(name);
    if (flag != nullptr && flag->is_diagnostic()) {
      jio_snprintf(errorbuf, buf_size, "VM option '%s' is diagnostic and must be enabled via -XX:+UnlockDiagnosticVMOptions.", name);
      delete matcher;
      return false;
    }
  }

  matcher->init(option, option_list);
  matcher->set_value<T>(value);
  option_list = matcher;
  command_set_in_filter(option);

  if (!CompilerOracle::be_quiet()) {
    // Print out the successful registration of a compile command
    ttyLocker ttyl;
    tty->print("CompileCommand: %s ", option2name(option));
    matcher->print();
  }

  return true;
}

template<typename T>
bool CompilerOracle::has_option_value(const methodHandle& method, CompileCommandEnum option, T& value) {
  assert(option_matches_type(option, value), "Value must match option type");
  if (!has_command(option)) {
    return false;
  }
  if (option_list != nullptr) {
    TypedMethodOptionMatcher* m = option_list->match(method, option);
    if (m != nullptr) {
      value = m->value<T>();
      return true;
    }
  }
  return false;
}

static bool resolve_inlining_predicate(CompileCommandEnum option, const methodHandle& method) {
  assert(option == CompileCommandEnum::Inline || option == CompileCommandEnum::DontInline, "Sanity");
  bool v1 = false;
  bool v2 = false;
  bool has_inline = CompilerOracle::has_option_value(method, CompileCommandEnum::Inline, v1);
  bool has_dnotinline = CompilerOracle::has_option_value(method, CompileCommandEnum::DontInline, v2);
  if (has_inline && has_dnotinline) {
    if (v1 && v2) {
      // Conflict options detected
      // Find the last one for that method and return the predicate accordingly
      // option_list lists options in reverse order. So the first option we find is the last which was specified.
      CompileCommandEnum last_one = CompileCommandEnum::Unknown;
      TypedMethodOptionMatcher* current = option_list;
      while (current != nullptr) {
        last_one = current->option();
        if (last_one == CompileCommandEnum::Inline || last_one == CompileCommandEnum::DontInline) {
          if (current->matches(method)) {
            return last_one == option;
          }
        }
        current = current->next();
      }
      ShouldNotReachHere();
      return false;
    } else {
      // No conflicts
      return option == CompileCommandEnum::Inline ? v1 : v2;
    }
  } else {
    if (option == CompileCommandEnum::Inline) {
      return has_inline ? v1 : false;
    } else {
      return has_dnotinline ? v2 : false;
    }
  }
}

static bool check_predicate(CompileCommandEnum option, const methodHandle& method) {
  // Special handling for Inline and DontInline since conflict options may be specified
  if (option == CompileCommandEnum::Inline || option == CompileCommandEnum::DontInline) {
    return resolve_inlining_predicate(option, method);
  }

  bool value = false;
  if (CompilerOracle::has_option_value(method, option, value)) {
    return value;
  }
  return false;
}

bool CompilerOracle::has_any_command_set() {
  return any_set;
}

// Explicit instantiation for all OptionTypes supported.
template bool CompilerOracle::has_option_value<intx>(const methodHandle& method, CompileCommandEnum option, intx& value);
template bool CompilerOracle::has_option_value<uintx>(const methodHandle& method, CompileCommandEnum option, uintx& value);
template bool CompilerOracle::has_option_value<bool>(const methodHandle& method, CompileCommandEnum option, bool& value);
template bool CompilerOracle::has_option_value<ccstr>(const methodHandle& method, CompileCommandEnum option, ccstr& value);
template bool CompilerOracle::has_option_value<double>(const methodHandle& method, CompileCommandEnum option, double& value);

template<typename T>
bool CompilerOracle::option_matches_type(CompileCommandEnum option, T& value) {
  enum OptionType option_type = option2type(option);
  if (option_type == OptionType::Unknown) {
    return false; // Can't query options with type Unknown.
  }
  if (option_type == OptionType::Ccstrlist) {
    option_type = OptionType::Ccstr; // CCstrList type options are stored as Ccstr
  }
  return (get_type_for<T>() == option_type);
}

template bool CompilerOracle::option_matches_type<intx>(CompileCommandEnum option, intx& value);
template bool CompilerOracle::option_matches_type<uintx>(CompileCommandEnum option, uintx& value);
template bool CompilerOracle::option_matches_type<bool>(CompileCommandEnum option, bool& value);
template bool CompilerOracle::option_matches_type<ccstr>(CompileCommandEnum option, ccstr& value);
template bool CompilerOracle::option_matches_type<double>(CompileCommandEnum option, double& value);

bool CompilerOracle::has_option(const methodHandle& method, CompileCommandEnum option) {
  bool value = false;
  has_option_value(method, option, value);
  return value;
}

bool CompilerOracle::should_exclude(const methodHandle& method) {
  if (check_predicate(CompileCommandEnum::Exclude, method)) {
    return true;
  }
  if (has_command(CompileCommandEnum::CompileOnly)) {
    return !check_predicate(CompileCommandEnum::CompileOnly, method);
  }
  return false;
}

bool CompilerOracle::should_inline(const methodHandle& method) {
  return (check_predicate(CompileCommandEnum::Inline, method));
}

bool CompilerOracle::should_not_inline(const methodHandle& method) {
  return check_predicate(CompileCommandEnum::DontInline, method) || check_predicate(CompileCommandEnum::Exclude, method);
}

bool CompilerOracle::should_print(const methodHandle& method) {
  return check_predicate(CompileCommandEnum::Print, method);
}

bool CompilerOracle::should_print_methods() {
  return has_command(CompileCommandEnum::Print);
}

// Tells whether there are any methods to collect memory statistics for
bool CompilerOracle::should_collect_memstat() {
  return has_command(CompileCommandEnum::MemStat) || has_command(CompileCommandEnum::MemLimit);
}

bool CompilerOracle::should_log(const methodHandle& method) {
  if (!LogCompilation) return false;
  if (!has_command(CompileCommandEnum::Log)) {
    return true;  // by default, log all
  }
  return (check_predicate(CompileCommandEnum::Log, method));
}

bool CompilerOracle::should_break_at(const methodHandle& method) {
  return check_predicate(CompileCommandEnum::Break, method);
}

void CompilerOracle::tag_blackhole_if_possible(const methodHandle& method) {
  if (!check_predicate(CompileCommandEnum::Blackhole, method)) {
    return;
  }
  guarantee(UnlockExperimentalVMOptions, "Checked during initial parsing");
  if (method->result_type() != T_VOID) {
    warning("Blackhole compile option only works for methods with void type: %s",
            method->name_and_sig_as_C_string());
    return;
  }
  if (!method->is_empty_method()) {
    warning("Blackhole compile option only works for empty methods: %s",
            method->name_and_sig_as_C_string());
    return;
  }
  if (!method->is_static()) {
    warning("Blackhole compile option only works for static methods: %s",
            method->name_and_sig_as_C_string());
    return;
  }
  if (method->intrinsic_id() == vmIntrinsics::_blackhole) {
    return;
  }
  if (method->intrinsic_id() != vmIntrinsics::_none) {
    warning("Blackhole compile option only works for methods that do not have intrinsic set: %s, %s",
            method->name_and_sig_as_C_string(), vmIntrinsics::name_at(method->intrinsic_id()));
    return;
  }
  method->set_intrinsic_id(vmIntrinsics::_blackhole);
}

static CompileCommandEnum match_option_name(const char* line, int* bytes_read, char* errorbuf, int bufsize) {
  assert(ARRAY_SIZE(option_names) == static_cast<int>(CompileCommandEnum::Count), "option_names size mismatch");

  *bytes_read = 0;
  char option_buf[256];
  int matches = sscanf(line, "%255[a-zA-Z0-9]%n", option_buf, bytes_read);
  if (matches > 0 && strcasecmp(option_buf, "unknown") != 0) {
    for (uint i = 0; i < ARRAY_SIZE(option_names); i++) {
      if (strcasecmp(option_buf, option_names[i]) == 0) {
        return static_cast<CompileCommandEnum>(i);
      }
    }
  }
  jio_snprintf(errorbuf, bufsize, "Unrecognized option '%s'", option_buf);
  return CompileCommandEnum::Unknown;
}

// match exactly and don't mess with errorbuf
CompileCommandEnum CompilerOracle::parse_option_name(const char* line) {
  for (uint i = 0; i < ARRAY_SIZE(option_names); i++) {
    if (strcasecmp(line, option_names[i]) == 0) {
      return static_cast<CompileCommandEnum>(i);
    }
  }
  return CompileCommandEnum::Unknown;
}

enum OptionType CompilerOracle::parse_option_type(const char* type_str) {
  for (uint i = 0; i < ARRAY_SIZE(optiontype_names); i++) {
    if (strcasecmp(type_str, optiontype_names[i]) == 0) {
      return static_cast<enum OptionType>(i);
    }
  }
  return OptionType::Unknown;
}

static void print_tip() { // CMH Update info
  tty->cr();
  tty->print_cr("Usage: '-XX:CompileCommand=<option>,<method pattern>' - to set boolean option to true");
  tty->print_cr("Usage: '-XX:CompileCommand=<option>,<method pattern>,<value>'");
  tty->print_cr("Use:   '-XX:CompileCommand=help' for more information and to list all option.");
  tty->cr();
}

static void print_option(CompileCommandEnum option, const char* name, enum OptionType type) {
  if (type != OptionType::Unknown) {
    tty->print_cr("    %s (%s)", name, optiontype2name(type));
  }
}

static void print_commands() {
  tty->cr();
  tty->print_cr("All available options:");
#define enum_of_options(option, name, ctype) print_option(CompileCommandEnum::option, name, OptionType::ctype);
  COMPILECOMMAND_OPTIONS(enum_of_options)
#undef enum_of_options
  tty->cr();
}

static void usage() {
  tty->cr();
  tty->print_cr("The CompileCommand option enables the user of the JVM to control specific");
  tty->print_cr("behavior of the dynamic compilers.");
  tty->cr();
  tty->print_cr("Compile commands has this general form:");
  tty->print_cr("-XX:CompileCommand=<option><method pattern><value>");
  tty->print_cr("    Sets <option> to the specified value for methods matching <method pattern>");
  tty->print_cr("    All options are typed");
  tty->cr();
  tty->print_cr("-XX:CompileCommand=<option><method pattern>");
  tty->print_cr("    Sets <option> to true for methods matching <method pattern>");
  tty->print_cr("    Only applies to boolean options.");
  tty->cr();
  tty->print_cr("-XX:CompileCommand=quiet");
  tty->print_cr("    Silence the compile command output");
  tty->cr();
  tty->print_cr("-XX:CompileCommand=help");
  tty->print_cr("    Prints this help text");
  tty->cr();
  print_commands();
  tty->cr();
    tty->print_cr("Method patterns has the format:");
  tty->print_cr("  package/Class.method()");
  tty->cr();
  tty->print_cr("For backward compatibility this form is also allowed:");
  tty->print_cr("  package.Class::method()");
  tty->cr();
  tty->print_cr("The signature can be separated by an optional whitespace or comma:");
  tty->print_cr("  package/Class.method ()");
  tty->cr();
  tty->print_cr("The class and method identifier can be used together with leading or");
  tty->print_cr("trailing *'s for wildcard matching:");
  tty->print_cr("  *ackage/Clas*.*etho*()");
  tty->cr();
  tty->print_cr("It is possible to use more than one CompileCommand on the command line:");
  tty->print_cr("  -XX:CompileCommand=exclude,java/*.* -XX:CompileCommand=log,java*.*");
  tty->cr();
  tty->print_cr("The CompileCommands can be loaded from a file with the flag");
  tty->print_cr("-XX:CompileCommandFile=<file> or be added to the file '.hotspot_compiler'");
  tty->print_cr("Use the same format in the file as the argument to the CompileCommand flag.");
  tty->print_cr("Add one command on each line.");
  tty->print_cr("  exclude java/*.*");
  tty->print_cr("  option java/*.* ReplayInline");
  tty->cr();
  tty->print_cr("The following commands have conflicting behavior: 'exclude', 'inline', 'dontinline',");
  tty->print_cr("and 'compileonly'. There is no priority of commands. Applying (a subset of) these");
  tty->print_cr("commands to the same method results in undefined behavior.");
  tty->cr();
  tty->print_cr("The 'exclude' command excludes methods from top-level compilations as well as");
  tty->print_cr("from inlining, whereas the 'compileonly' command only excludes methods from");
  tty->print_cr("top-level compilations (i.e. they can still be inlined into other compilation units).");
  tty->cr();
};

static int skip_whitespace(char* &line) {
  // Skip any leading spaces
  int whitespace_read = 0;
  sscanf(line, "%*[ \t]%n", &whitespace_read);
  line += whitespace_read;
  return whitespace_read;
}

static void skip_comma(char* &line) {
  // Skip any leading spaces
  if (*line == ',') {
    line++;
  }
}

static bool parseMemLimit(const char* line, intx& value, int& bytes_read, char* errorbuf, const int buf_size) {
  // Format:
  // "<memory size>['~' <suboption>]"
  // <memory size> can have units, e.g. M
  // <suboption> one of "crash" "stop", if omitted, "stop" is implied.
  //
  // Examples:
  // -XX:CompileCommand='memlimit,*.*,20m'
  // -XX:CompileCommand='memlimit,*.*,20m~stop'
  // -XX:CompileCommand='memlimit,Option::toString,1m~crash'
  //
  // The resulting intx carries the size and whether we are to stop or crash:
  // - neg. value means crash
  // - pos. value (default) means stop
  size_t s = 0;
  char* end;
  if (!parse_integer<size_t>(line, &end, &s)) {
    jio_snprintf(errorbuf, buf_size, "MemLimit: invalid value");
    return false;
  }
  bytes_read = (int)(end - line);

  intx v = (intx)s;
  if ((*end) != '\0') {
    if (strncasecmp(end, "~crash", 6) == 0) {
      v = -v;
      bytes_read += 6;
    } else if (strncasecmp(end, "~stop", 5) == 0) {
      // ok, this is the default
      bytes_read += 5;
    } else {
      jio_snprintf(errorbuf, buf_size, "MemLimit: invalid option");
      return false;
    }
  }
  value = v;
  return true;
}

static bool parseMemStat(const char* line, uintx& value, int& bytes_read, char* errorbuf, const int buf_size) {

#define IF_ENUM_STRING(S, CMD)                \
  if (strncasecmp(line, S, strlen(S)) == 0) { \
    bytes_read += (int)strlen(S);             \
    CMD                                       \
    return true;                              \
  }

  IF_ENUM_STRING("collect", {
    value = (uintx)MemStatAction::collect;
  });
  IF_ENUM_STRING("print", {
    value = (uintx)MemStatAction::print;
  });
#undef IF_ENUM_STRING

  jio_snprintf(errorbuf, buf_size, "MemStat: invalid option");

  return false;
}

static bool scan_value(enum OptionType type, char* line, int& total_bytes_read,
        TypedMethodOptionMatcher* matcher, CompileCommandEnum option, char* errorbuf, const int buf_size) {
  int bytes_read = 0;
  const char* ccname = option2name(option);
  const char* type_str = optiontype2name(type);
  int skipped = skip_whitespace(line);
  total_bytes_read += skipped;
  if (type == OptionType::Intx) {
    intx value;
    bool success = false;
    if (option == CompileCommandEnum::MemLimit) {
      // Special parsing for MemLimit
      success = parseMemLimit(line, value, bytes_read, errorbuf, buf_size);
    } else {
      // Is it a raw number?
      success = sscanf(line, "%zd%n", &value, &bytes_read) == 1;
    }
    if (success) {
      total_bytes_read += bytes_read;
      return register_command(matcher, option, errorbuf, buf_size, value);
    } else {
      jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
      return false;
    }
  } else if (type == OptionType::Uintx) {
    uintx value;
    bool success = false;
    if (option == CompileCommandEnum::MemStat) {
      // Special parsing for MemStat
      success = parseMemStat(line, value, bytes_read, errorbuf, buf_size);
    } else {
      // parse as raw number
      success = sscanf(line, "%zu%n", &value, &bytes_read) == 1;
    }
    if (success) {
      total_bytes_read += bytes_read;
      return register_command(matcher, option, errorbuf, buf_size, value);
    } else {
      jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
      return false;
    }
  } else if (type == OptionType::Ccstr) {
    ResourceMark rm;
    char* value = NEW_RESOURCE_ARRAY(char, strlen(line) + 1);
    if (sscanf(line, "%255[_a-zA-Z0-9]%n", value, &bytes_read) == 1) {
      total_bytes_read += bytes_read;
      return register_command(matcher, option, errorbuf, buf_size, (ccstr) value);
    } else {
      jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
      return false;
    }
  } else if (type == OptionType::Ccstrlist) {
    // Accumulates several strings into one. The internal type is ccstr.
    ResourceMark rm;
    char* value = NEW_RESOURCE_ARRAY(char, strlen(line) + 1);
    char* next_value = value;
    if (sscanf(line, "%255[_a-zA-Z0-9+\\-]%n", next_value, &bytes_read) == 1) {
      total_bytes_read += bytes_read;
      line += bytes_read;
      next_value += bytes_read + 1;
      char* end_value = next_value - 1;
      while (sscanf(line, "%*[ \t]%255[_a-zA-Z0-9+\\-]%n", next_value, &bytes_read) == 1) {
        total_bytes_read += bytes_read;
        line += bytes_read;
        *end_value = ' '; // override '\0'
        next_value += bytes_read;
        end_value = next_value-1;
      }

      if (option == CompileCommandEnum::ControlIntrinsic || option == CompileCommandEnum::DisableIntrinsic) {
        ControlIntrinsicValidator validator(value, (option == CompileCommandEnum::DisableIntrinsic));

        if (!validator.is_valid()) {
          jio_snprintf(errorbuf, buf_size, "Unrecognized intrinsic detected in %s: %s", option2name(option), validator.what());
          return false;
        }
      }
#if !defined(PRODUCT) && defined(COMPILER2)
      else if (option == CompileCommandEnum::TraceAutoVectorization) {
        TraceAutoVectorizationTagValidator validator(value, true);

        if (!validator.is_valid()) {
          jio_snprintf(errorbuf, buf_size, "Unrecognized tag name in %s: %s", option2name(option), validator.what());
          return false;
        }
      } else if (option == CompileCommandEnum::TraceMergeStores) {
        TraceMergeStores::TagValidator validator(value, true);

        if (!validator.is_valid()) {
          jio_snprintf(errorbuf, buf_size, "Unrecognized tag name in %s: %s", option2name(option), validator.what());
          return false;
        }
      } else if (option == CompileCommandEnum::PrintIdealPhase) {
        PhaseNameValidator validator(value);

        if (!validator.is_valid()) {
          jio_snprintf(errorbuf, buf_size, "Unrecognized phase name in %s: %s", option2name(option), validator.what());
          return false;
        }
      } else if (option == CompileCommandEnum::TestOptionList) {
        // all values are ok
      }
#endif
      else {
        assert(false, "Ccstrlist type option missing validator");
      }

      return register_command(matcher, option, errorbuf, buf_size, (ccstr) value);
    } else {
      jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
      return false;
    }
  } else if (type == OptionType::Bool) {
    char value[256];
    if (*line == '\0') {
      // Short version of a CompileCommand sets a boolean Option to true
      // -XXCompileCommand=<Option>,<method pattern>
      return register_command(matcher, option, errorbuf, buf_size,true);
    }
    if (sscanf(line, "%255[a-zA-Z]%n", value, &bytes_read) == 1) {
      if (strcasecmp(value, "true") == 0) {
        total_bytes_read += bytes_read;
        return register_command(matcher, option, errorbuf, buf_size,true);
      } else if (strcasecmp(value, "false") == 0) {
        total_bytes_read += bytes_read;
        return register_command(matcher, option, errorbuf, buf_size,false);
      } else {
        jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
        return false;
      }
    } else {
      jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
      return false;
    }
  } else if (type == OptionType::Double) {
    char buffer[2][256];
    // Decimal separator '.' has been replaced with ' ' or '/' earlier,
    // so read integer and fraction part of double value separately.
    if (sscanf(line, "%255[0-9]%*[ /\t]%255[0-9]%n", buffer[0], buffer[1], &bytes_read) == 2) {
      char value[512] = "";
      jio_snprintf(value, sizeof(value), "%s.%s", buffer[0], buffer[1]);
      total_bytes_read += bytes_read;
      return register_command(matcher, option, errorbuf, buf_size, atof(value));
    } else {
      jio_snprintf(errorbuf, buf_size, "Value cannot be read for option '%s' of type '%s'", ccname, type_str);
      return false;
    }
  } else {
    jio_snprintf(errorbuf, buf_size, "Type '%s' not supported ", type_str);
    return false;
  }
}

// Scan next option and value in line, return MethodMatcher object on success, nullptr on failure.
// On failure, error_msg contains description for the first error.
// For future extensions: set error_msg on first error.
static bool scan_option_and_value(enum OptionType type, char* line, int& total_bytes_read,
                                TypedMethodOptionMatcher* matcher,
                                char* errorbuf, const int buf_size) {
  total_bytes_read = 0;
  int bytes_read = 0;
  char option_buf[256];

  // Read option name.
  if (sscanf(line, "%*[ \t]%255[a-zA-Z0-9]%n", option_buf, &bytes_read) == 1) {
    line += bytes_read;
    total_bytes_read += bytes_read;
    int bytes_read2 = 0;
    total_bytes_read += skip_whitespace(line);
    CompileCommandEnum option = match_option_name(option_buf, &bytes_read2, errorbuf, buf_size);
    if (option == CompileCommandEnum::Unknown) {
      assert(*errorbuf != '\0', "error must have been set");
      return false;
    }
    enum OptionType optiontype = option2type(option);
    if (option2type(option) != type) {
      const char* optiontype_name = optiontype2name(optiontype);
      const char* type_name = optiontype2name(type);
      jio_snprintf(errorbuf, buf_size, "Option '%s' with type '%s' doesn't match supplied type '%s'", option_buf, optiontype_name, type_name);
      return false;
    }
    return scan_value(type, line, total_bytes_read, matcher, option, errorbuf, buf_size);
  } else {
    const char* type_str = optiontype2name(type);
    jio_snprintf(errorbuf, buf_size, "Option name for type '%s' should be alphanumeric ", type_str);
    return false;
  }
}

void CompilerOracle::print_parse_error(char* error_msg, char* original_line) {
  assert(*error_msg != '\0', "Must have error_message");
  ttyLocker ttyl;
  tty->print_cr("CompileCommand: An error occurred during parsing");
  tty->print_cr("Error: %s", error_msg);
  tty->print_cr("Line: '%s'", original_line);
  print_tip();
}

class LineCopy : StackObj {
  const char* _copy;
public:
    LineCopy(char* line) {
      _copy = os::strdup(line, mtInternal);
    }
    ~LineCopy() {
      os::free((void*)_copy);
    }
    char* get() {
      return (char*)_copy;
    }
};

bool CompilerOracle::parse_from_line_quietly(char* line) {
  const bool quiet0 = _quiet;
  _quiet = true;
  const bool result = parse_from_line(line);
  _quiet = quiet0;
  return result;
}

bool CompilerOracle::parse_from_line(char* line) {
  if ((line[0] == '\0') || (line[0] == '#')) {
    return true;
  }

  LineCopy original(line);
  int bytes_read;
  char error_buf[1024] = {0};

  CompileCommandEnum option = match_option_name(line, &bytes_read, error_buf, sizeof(error_buf));
  line += bytes_read;
  ResourceMark rm;

  if (option == CompileCommandEnum::Unknown) {
    print_parse_error(error_buf, original.get());
    return false;
  }

  if (option == CompileCommandEnum::Quiet) {
    _quiet = true;
    return true;
  }

  if (option == CompileCommandEnum::Help) {
    usage();
    return true;
  }

  if (option == CompileCommandEnum::Option) {
    // Look for trailing options.
    //
    // Two types of trailing options are
    // supported:
    //
    // (1) CompileCommand=option,Klass::method,option
    // (2) CompileCommand=option,Klass::method,type,option,value
    //
    // Type (1) is used to enable a boolean option for a method.
    //
    // Type (2) is used to support options with a value. Values can have the
    // the following types: intx, uintx, bool, ccstr, ccstrlist, and double.

    char option_type[256]; // stores option for Type (1) and type of Type (2)
    skip_comma(line);
    TypedMethodOptionMatcher* archetype = TypedMethodOptionMatcher::parse_method_pattern(line, error_buf, sizeof(error_buf));
    if (archetype == nullptr) {
      print_parse_error(error_buf, original.get());
      return false;
    }

    skip_whitespace(line);

    // This is unnecessarily complex. Should retire multi-option lines and skip while loop
    while (sscanf(line, "%255[a-zA-Z0-9]%n", option_type, &bytes_read) == 1) {
      line += bytes_read;

      // typed_matcher is used as a blueprint for each option, deleted at the end
      TypedMethodOptionMatcher* typed_matcher = archetype->clone();
      enum OptionType type = parse_option_type(option_type);
      if (type != OptionType::Unknown) {
        // Type (2) option: parse option name and value.
        if (!scan_option_and_value(type, line, bytes_read, typed_matcher, error_buf, sizeof(error_buf))) {
          print_parse_error(error_buf, original.get());
          return false;
        }
        line += bytes_read;
      } else {
        // Type (1) option - option_type contains the option name -> bool value = true is implied
        int bytes_read;
        CompileCommandEnum option = match_option_name(option_type, &bytes_read, error_buf, sizeof(error_buf));
        if (option == CompileCommandEnum::Unknown) {
          print_parse_error(error_buf, original.get());
          return false;
        }
        if (option2type(option) == OptionType::Bool) {
          if (!register_command(typed_matcher, option, error_buf, sizeof(error_buf), true)) {
            print_parse_error(error_buf, original.get());
            return false;
          }
        } else {
          jio_snprintf(error_buf, sizeof(error_buf), "  Missing type '%s' before option '%s'",
                       optiontype2name(option2type(option)), option2name(option));
          print_parse_error(error_buf, original.get());
          return false;
        }
      }
      assert(typed_matcher != nullptr, "sanity");
      assert(*error_buf == '\0', "No error here");
      skip_whitespace(line);
    } // while(
    delete archetype;
  } else {  // not an OptionCommand
    // Command has the following form:
    // CompileCommand=<option>,<method pattern><value>
    // CompileCommand=<option>,<method pattern>     (implies option is bool and value is true)
    assert(*error_buf == '\0', "Don't call here with error_buf already set");
    enum OptionType type = option2type(option);
    int bytes_read = 0;
    skip_comma(line);
    TypedMethodOptionMatcher* matcher = TypedMethodOptionMatcher::parse_method_pattern(line, error_buf, sizeof(error_buf));
    if (matcher == nullptr) {
      print_parse_error(error_buf, original.get());
      return false;
    }
    skip_whitespace(line);
    if (*line == '\0') {
      if (option2type(option) == OptionType::Bool) {
        // if this is a bool option this implies true
        if (!register_command(matcher, option, error_buf, sizeof(error_buf), true)) {
          print_parse_error(error_buf, original.get());
          return false;
        }
        return true;
      } else if (option == CompileCommandEnum::MemStat) {
        // MemStat default action is to collect data but to not print
        if (!register_command(matcher, option, error_buf, sizeof(error_buf), (uintx)MemStatAction::collect)) {
          print_parse_error(error_buf, original.get());
          return false;
        }
        return true;
      } else {
        jio_snprintf(error_buf, sizeof(error_buf), "  Option '%s' is not followed by a value", option2name(option));
        print_parse_error(error_buf, original.get());
        return false;
      }
    }
    if (!scan_value(type, line, bytes_read, matcher, option, error_buf, sizeof(error_buf))) {
      print_parse_error(error_buf, original.get());
      return false;
    }
    assert(matcher != nullptr, "consistency");
  }
  return true;
}

static const char* default_cc_file = ".hotspot_compiler";

static const char* cc_file() {
#ifdef ASSERT
  if (CompileCommandFile == nullptr)
    return default_cc_file;
#endif
  return CompileCommandFile;
}

bool CompilerOracle::has_command_file() {
  return cc_file() != nullptr;
}

bool CompilerOracle::_quiet = false;

bool CompilerOracle::parse_from_file() {
  assert(has_command_file(), "command file must be specified");
  FILE* stream = os::fopen(cc_file(), "rt");
  if (stream == nullptr) {
    return true;
  }

  FileInput input(stream, /*need_close=*/ true);
  return parse_from_input(&input, parse_from_line);
}

bool CompilerOracle::parse_from_input(inputStream::Input* input,
                                      CompilerOracle::
                                      parse_from_line_fn_t* parse_from_line) {
  bool success = true;
  for (inputStream in(input); !in.done(); in.next()) {
    if (!parse_from_line(in.current_line())) {
      success = false;
    }
  }
  return success;
}

bool CompilerOracle::parse_from_string(const char* str,
                                       CompilerOracle::
                                       parse_from_line_fn_t* parse_from_line) {
  MemoryInput input(str, strlen(str));
  return parse_from_input(&input, parse_from_line);
}

bool compilerOracle_init() {
  bool success = true;
  // Register default compile commands first - any commands specified via CompileCommand will
  // supersede these default commands.
  for (int i = 0; default_compile_commands[i] != nullptr; i ++) {
    char* s = os::strdup(default_compile_commands[i]);
    success = CompilerOracle::parse_from_line_quietly(s);
    os::free(s);
    assert(success, "default compile command \"%s\" failed to parse", default_compile_commands[i]);
  }
  if (!CompilerOracle::parse_from_string(CompileCommand, CompilerOracle::parse_from_line)) {
    success = false;
  }
  if (!CompilerOracle::parse_from_string(CompileOnly, CompilerOracle::parse_compile_only)) {
    success = false;
  }
  if (CompilerOracle::has_command_file()) {
    if (!CompilerOracle::parse_from_file()) {
      success = false;
    }
  } else {
    struct stat buf;
    if (os::stat(default_cc_file, &buf) == 0) {
      warning("%s file is present but has been ignored.  "
              "Run with -XX:CompileCommandFile=%s to load the file.",
              default_cc_file, default_cc_file);
    }
  }
  if (has_command(CompileCommandEnum::Print)) {
    if (PrintAssembly) {
      warning("CompileCommand and/or %s file contains 'print' commands, but PrintAssembly is also enabled", default_cc_file);
    }
  }
  return success;
}

bool CompilerOracle::parse_compile_only(char* line) {
  if (line[0] == '\0') {
    return true;
  }
  ResourceMark rm;
  char error_buf[1024] = {0};
  LineCopy original(line);
  char* method_pattern;
  do {
    if (line[0] == '\0') {
      break;
    }
    method_pattern = strtok_r(line, ",", &line);
    if (method_pattern != nullptr) {
      TypedMethodOptionMatcher* matcher = TypedMethodOptionMatcher::parse_method_pattern(method_pattern, error_buf, sizeof(error_buf));
      if (matcher != nullptr) {
        if (register_command(matcher, CompileCommandEnum::CompileOnly, error_buf, sizeof(error_buf), true)) {
          continue;
        }
      }
    }
    ttyLocker ttyl;
    tty->print_cr("CompileOnly: An error occurred during parsing");
    if (*error_buf != '\0') {
      tty->print_cr("Error: %s", error_buf);
    }
    tty->print_cr("Line: '%s'", original.get());
    return false;
  } while (method_pattern != nullptr && line != nullptr);
  return true;
}

CompileCommandEnum CompilerOracle::string_to_option(const char* name) {
  int bytes_read = 0;
  char errorbuf[1024] = {0};
  return match_option_name(name, &bytes_read, errorbuf, sizeof(errorbuf));
}