lldb/source/Plugins/Process/POSIX/ProcessPOSIXLog.cpp

//===-- ProcessPOSIXLog.cpp ---------------------------------------*- C++
//-*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "ProcessPOSIXLog.h"

#include <mutex>

#include "lldb/Core/StreamFile.h"
#include "lldb/Interpreter/Args.h"

#include "ProcessPOSIXLog.h"

using namespace lldb;
using namespace lldb_private;

// We want to avoid global constructors where code needs to be run so here we
// control access to our static g_log_sp by hiding it in a singleton function
// that will construct the static g_log_sp the first time this function is
// called.
static bool g_log_enabled = false;
static Log *g_log = NULL;
static Log *GetLog() {
  if (!g_log_enabled)
    return NULL;
  return g_log;
}

void ProcessPOSIXLog::Initialize(ConstString name) {
  static std::once_flag g_once_flag;

  std::call_once(g_once_flag, [name]() {
    Log::Callbacks log_callbacks = {DisableLog, EnableLog, ListLogCategories};

    Log::RegisterLogChannel(name, log_callbacks);
    RegisterPluginName(name);
  });
}

Log *ProcessPOSIXLog::GetLogIfAllCategoriesSet(uint32_t mask) {
  Log *log(GetLog());
  if (log && mask) {
    uint32_t log_mask = log->GetMask().Get();
    if ((log_mask & mask) != mask)
      return NULL;
  }
  return log;
}

static uint32_t GetFlagBits(const char *arg) {
  if (::strcasecmp(arg, "all") == 0)
    return POSIX_LOG_ALL;
  else if (::strcasecmp(arg, "async") == 0)
    return POSIX_LOG_ASYNC;
  else if (::strncasecmp(arg, "break", 5) == 0)
    return POSIX_LOG_BREAKPOINTS;
  else if (::strncasecmp(arg, "comm", 4) == 0)
    return POSIX_LOG_COMM;
  else if (::strcasecmp(arg, "default") == 0)
    return POSIX_LOG_DEFAULT;
  else if (::strcasecmp(arg, "packets") == 0)
    return POSIX_LOG_PACKETS;
  else if (::strcasecmp(arg, "memory") == 0)
    return POSIX_LOG_MEMORY;
  else if (::strcasecmp(arg, "data-short") == 0)
    return POSIX_LOG_MEMORY_DATA_SHORT;
  else if (::strcasecmp(arg, "data-long") == 0)
    return POSIX_LOG_MEMORY_DATA_LONG;
  else if (::strcasecmp(arg, "process") == 0)
    return POSIX_LOG_PROCESS;
  else if (::strcasecmp(arg, "ptrace") == 0)
    return POSIX_LOG_PTRACE;
  else if (::strcasecmp(arg, "registers") == 0)
    return POSIX_LOG_REGISTERS;
  else if (::strcasecmp(arg, "step") == 0)
    return POSIX_LOG_STEP;
  else if (::strcasecmp(arg, "thread") == 0)
    return POSIX_LOG_THREAD;
  else if (::strcasecmp(arg, "verbose") == 0)
    return POSIX_LOG_VERBOSE;
  else if (::strncasecmp(arg, "watch", 5) == 0)
    return POSIX_LOG_WATCHPOINTS;
  return 0;
}

void ProcessPOSIXLog::DisableLog(const char **args, Stream *feedback_strm) {
  Log *log(GetLog());
  if (log) {
    uint32_t flag_bits = 0;

    flag_bits = log->GetMask().Get();
    for (; args[0]; args++) {
      const char *arg = args[0];
      uint32_t bits = GetFlagBits(arg);

      if (bits) {
        flag_bits &= ~bits;
      } else {
        feedback_strm->Printf("error: unrecognized log category '%s'\n", arg);
        ListLogCategories(feedback_strm);
      }
    }

    log->GetMask().Reset(flag_bits);
    if (flag_bits == 0)
      g_log_enabled = false;
  }

  return;
}

Log *ProcessPOSIXLog::EnableLog(StreamSP &log_stream_sp, uint32_t log_options,
                                const char **args, Stream *feedback_strm) {
  // Try see if there already is a log - that way we can reuse its settings.
  // We could reuse the log in toto, but we don't know that the stream is the
  // same.
  uint32_t flag_bits = 0;
  if (g_log)
    flag_bits = g_log->GetMask().Get();

  // Now make a new log with this stream if one was provided
  if (log_stream_sp) {
    if (g_log)
      g_log->SetStream(log_stream_sp);
    else
      g_log = new Log(log_stream_sp);
  }

  if (g_log) {
    bool got_unknown_category = false;
    for (; args[0]; args++) {
      const char *arg = args[0];
      uint32_t bits = GetFlagBits(arg);

      if (bits) {
        flag_bits |= bits;
      } else {
        feedback_strm->Printf("error: unrecognized log category '%s'\n", arg);
        if (got_unknown_category == false) {
          got_unknown_category = true;
          ListLogCategories(feedback_strm);
        }
      }
    }
    if (flag_bits == 0)
      flag_bits = POSIX_LOG_DEFAULT;
    g_log->GetMask().Reset(flag_bits);
    g_log->GetOptions().Reset(log_options);
    g_log_enabled = true;
  }
  return g_log;
}

void ProcessPOSIXLog::ListLogCategories(Stream *strm) {
  strm->Printf(
      "Logging categories for '%s':\n"
      "  all - turn on all available logging categories\n"
      "  async - log asynchronous activity\n"
      "  break - log breakpoints\n"
      "  communication - log communication activity\n"
      "  default - enable the default set of logging categories for liblldb\n"
      "  packets - log gdb remote packets\n"
      "  memory - log memory reads and writes\n"
      "  data-short - log memory bytes for memory reads and writes for short "
      "transactions only\n"
      "  data-long - log memory bytes for memory reads and writes for all "
      "transactions\n"
      "  process - log process events and activities\n"
#ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
      "  ptrace - log all calls to ptrace\n"
#endif
      "  registers - log register read/writes\n"
      "  thread - log thread events and activities\n"
      "  step - log step related activities\n"
      "  verbose - enable verbose logging\n"
      "  watch - log watchpoint related activities\n",
      ProcessPOSIXLog::m_pluginname);
}

void ProcessPOSIXLog::LogIf(uint32_t mask, const char *format, ...) {
  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(mask));
  if (log) {
    va_list args;
    va_start(args, format);
    log->VAPrintf(format, args);
    va_end(args);
  }
}

int ProcessPOSIXLog::m_nestinglevel;
const char *ProcessPOSIXLog::m_pluginname = "";