bug.h

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//
// bug.h
//
// Copyright (C) 1996 Limit Point Systems, Inc.
//
// Author: Curtis Janssen <cljanss@limitpt.com>
// Maintainer: LPS
//
// This file is part of the SC Toolkit.
//
// The SC Toolkit is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// The SC Toolkit 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 Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
// the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
//
// The U.S. Government is granted a limited license as per AL 91-7.
//
 
#ifndef MPQC4_SRC_MPQC_UTIL_MISC_BUG_H_
#define MPQC4_SRC_MPQC_UTIL_MISC_BUG_H_
 
#include <cassert>
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
 
#include <pthread.h>
#if defined(__APPLE__) && defined(__x86_64__)
#include <mach/mach.h>
#include <stdexcept>
#endif
 
namespace TiledArray {
namespace detail {
 
class MemoryWatchpoint_x86_64 {
 public:
  // x86 debugging registers are described in see
  // https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-system-programming-manual-325384.html
  enum DebugRegister { kDR0 = 0, kDR1 = 1, kDR2 = 2, kDR3 = 3 };
 
  enum Size {
    kByte = 0,      // 1 byte  - 00
    kHalfWord = 1,  // 2 bytes - 01
    kWord = 3,      // 4 bytes - 11
                //        kDoubleWord = 2,  // 8 bytes - 10  NOT SUPPORTED BY
                //        SOME CHIPS!
    kSizeMask = 3  // mask      11
  };
 
  enum BreakState {
    kDisabled = 0,         // disabled   - 00
    kEnabledLocally = 1,   // task local - 01
    kEnabledGlobally = 2,  // global     - 10
    kBreakStateMask = 3    // mask         11
  };
 
  enum Condition {
    kWhenExecuted = 0,       // on execution     - 00
    kWhenWritten = 1,        // on write         - 01
    kWhenWrittenOrRead = 3,  // on read or write - 11
    kConditionMask = 3       // mask               11
  };
 
  class Pool {
   public:
    static constexpr const size_t nwatchpoints_per_thread = 4;
 
    ~Pool() = default;
 
    static void initialize_instance(
        const std::vector<const pthread_t *> &threads) {
      get_instance() = std::shared_ptr<Pool>(new Pool(threads));
    }
 
    static std::shared_ptr<Pool> instance() {
      auto result = get_instance();
      assert(result &&
             "Pool::instance() called but Pool::initialize_instance() had not "
             "been called");
      return result;
    }
 
    Pool &set(void *addr, Size size, Condition cond, const pthread_t *thread) {
      const auto it = pool_.find(thread);
      assert(it != pool_.end());
      // make sure there is no watchpoint for this address already
      for (auto &watchpt_ptr : it->second) {
        if (watchpt_ptr && watchpt_ptr->address() == addr) return *this;
      }
      // now create a watchpoint
      for (auto dr = 0; dr != nwatchpoints_per_thread; ++dr) {
        auto &watchpt_ptr = it->second[dr];
        if (!watchpt_ptr) {
          watchpt_ptr = std::make_shared<MemoryWatchpoint_x86_64>(
              addr, size, cond, static_cast<DebugRegister>(dr), thread);
          return *this;
        }
      }
      return *this;
    }
 
    MemoryWatchpoint_x86_64 *find(void *addr, const pthread_t *thread) {
      const auto it = pool_.find(thread);
      assert(it != pool_.end());
      for (auto &watchpt_ptr : it->second) {
        if (watchpt_ptr && watchpt_ptr->address() == addr)
          return watchpt_ptr.get();
      }
      return nullptr;
    }
 
    Pool &clear(void *addr, const pthread_t *thread) {
      const auto it = pool_.find(thread);
      assert(it != pool_.end());
      for (auto &watchpt_ptr : it->second) {
        if (watchpt_ptr && watchpt_ptr->address() == addr) {
          watchpt_ptr.reset();
          return *this;
        }
      }
      return *this;
    }
 
   private:
    std::unordered_map<const pthread_t *,
                       std::vector<std::shared_ptr<MemoryWatchpoint_x86_64>>>
        pool_;
 
    explicit Pool(const std::vector<const pthread_t *> &threads) {
      for (const auto &thread : threads) {
        assert(thread != nullptr);
        pool_[thread].resize(nwatchpoints_per_thread);
      }
    }
 
    static std::shared_ptr<Pool> &get_instance() {
      static std::shared_ptr<Pool> instance_;
      return instance_;
    }
  };
 
  MemoryWatchpoint_x86_64(void *addr, Size size, Condition cond,
                          DebugRegister dr, const pthread_t *thread)
      : addr_(addr), size_(size), cond_(cond), dr_(dr), thread_(thread) {
    init(true);
  }
 
  ~MemoryWatchpoint_x86_64() { init(false); }
 
  void *address() const { return addr_; }
  Size size() const { return size_; }
  Condition condition() const { return cond_; }
  DebugRegister debug_register() const { return dr_; }
 
 private:
  void *addr_;
  Size size_;
  Condition cond_;
  DebugRegister dr_;
  const pthread_t *thread_;
 
  inline uint64_t MakeFlags(DebugRegister reg, BreakState state, Condition cond,
                            Size size) {
    // N.B. each register takes 2 bits in DR7
    return (state | cond << 16 | size << 24) << (2 * reg);
  }
 
  inline uint64_t MakeMask(DebugRegister reg) {
    return MakeFlags(reg, kBreakStateMask, kConditionMask, kSizeMask);
  }
 
  friend class MemoryWatchPool;
 
  void init(bool create) {
#if defined(__APPLE__) && defined(__x86_64__)
    x86_debug_state dr;
    mach_msg_type_number_t dr_count = x86_DEBUG_STATE_COUNT;
 
    mach_port_t target_mach_thread = pthread_mach_thread_np(*thread_);
 
    kern_return_t rc =
        thread_get_state(target_mach_thread, x86_DEBUG_STATE,
                         reinterpret_cast<thread_state_t>(&dr), &dr_count);
 
    if (create && rc != KERN_SUCCESS)
      throw std::runtime_error(
          "MemoryWatchpoint_x86_64::MemoryWatchpoint_x86_64(): "
          "thread_get_state failed");
 
    switch (dr_) {
      case kDR0:
        dr.uds.ds64.__dr0 = reinterpret_cast<uint64_t>(addr_);
        break;
      case kDR1:
        dr.uds.ds64.__dr1 = reinterpret_cast<uint64_t>(addr_);
        break;
      case kDR2:
        dr.uds.ds64.__dr2 = reinterpret_cast<uint64_t>(addr_);
        break;
      case kDR3:
        dr.uds.ds64.__dr3 = reinterpret_cast<uint64_t>(addr_);
        break;
    }
 
    dr.uds.ds64.__dr7 &= ~MakeMask(dr_);
 
    dr.uds.ds64.__dr7 |=
        MakeFlags(dr_, create ? kEnabledLocally : kDisabled, cond_, size_);
 
    rc = thread_set_state(target_mach_thread, x86_DEBUG_STATE,
                          reinterpret_cast<thread_state_t>(&dr), dr_count);
 
    if (create && rc != KERN_SUCCESS)
      throw std::runtime_error(
          "MemoryWatchpoint_x86_64::MemoryWatchpoint_x86_64(): "
          "thread_set_state failed");
#endif  // defined(__APPLE__) && defined(__x86_64__)
  }
};
 
}  // namespace detail
}  // namespace TiledArray
 
namespace TiledArray {
 
class Debugger {
 protected:
  std::string prefix_;
  std::string exec_;
  std::string cmd_;
  volatile int debugger_ready_;
 
  bool debug_;
  bool traceback_;
  bool exit_on_signal_;
  bool sleep_;
  bool wait_for_debugger_;
  bool handle_sigint_;
  int *mysigs_;
 
  void init();
 
  static std::shared_ptr<Debugger> default_debugger_;
 
  static void __traceback(const std::string &prefix,
                          const char *reason = nullptr);
 
 public:
  explicit Debugger(const char *exec = nullptr);
  virtual ~Debugger();
 
  virtual void debug(const char *reason);
  virtual void traceback(const char *reason);
  virtual void set_debug_on_signal(int);
  virtual void set_traceback_on_signal(int);
  virtual void set_exit_on_signal(int);
  virtual void set_wait_for_debugger(int);
 
  virtual void handle(int sig);
  virtual void release(int sig);
  virtual void handle_defaults();
 
  virtual void set_prefix(const char *p);
  virtual void set_prefix(int p);
 
  virtual void set_cmd(const char *);
  virtual void default_cmd();
  virtual void set_exec(const char *);
 
  virtual void got_signal(int sig);
 
  static void set_default_debugger(const std::shared_ptr<Debugger> &);
  static std::shared_ptr<Debugger> default_debugger();
 
 private:
  void resolve_cmd_alias();
};
 
void launch_gdb_xterm();
void launch_lldb_xterm();
 
}  // namespace TiledArray
 
#endif  // MPQC4_SRC_MPQC_UTIL_MISC_BUG_H_
 
// Local Variables:
// mode: c++
// c-file-style: "CLJ"
// End: