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