Firebreath NPAPI Plugin How to Log - c++

Question

How to output log messages with an NPAPI plugin built with FireBreath in C++.
The log should be available during development and test and/or in Debug builds.
Modified:
The FireBreath way to log is with Log4cplus, and I have attempted to implement as closely as I can to these instructions.
I appended add_firebreath_library(log4cplus) to the bottom of "PluginConfig.cmake".
I have not yet been able to create a log file that I can read on Windows 8. I have browsed through other resources, such as this: FBLOG_TRACE() No logging to Logfile -- FBLOG_INFO() logging OK -- What is the DIFFERENCE
So far, all of my logging attempts are as follows:
#include "logging.h"
...
FBLOG_INFO("my function name", "and some text");
Optional Debug Level:
I am not sure if I have to override getLogLevel() because I am happy with the default level of INFO, and I am not sure exactly where to put it if I do override it:
FB::Log::LogLevel getLogLevel(){
return FB::Log::LogLevel_Trace; // Now Trace and above is logged.
}
Log File Path:
I am also uncertain about the proper path to writing the log file in windows. I have tried:
- outMethods.push_back(std::make_pair(FB::Log::LogMethod_File, "C:/logs/XXXX/yyyy.log"));
- outMethods.push_back(std::make_pair(FB::Log::LogMethod_File, "C:\logs\XXXX\yyyy.log"));
- outMethods.push_back(std::make_pair(FB::Log::LogMethod_File, "/logs/XXXX/yyyy.log"));
etc.
Prep Script Errors:
After enabling Log4cplus in "PluginConfig.cmake" with add_firebreath_library(log4cplus), I get some "not found" errors in my prep script on Windows, but the script otherwise appears to complete successfully, and my plugin builds without error, so I have chosen to so far ignore these errors. But, here they are:
Note: Partial path replacement with 'XXXXX'.
Z:\XXXXX\firebreath>firebreath-dev\prep2010.cmd projects fbbuildwin
A subdirectory or file fbbuildwin already exists.
Using projects in: "Z:\XXXXX\firebreath\projects"
Generating build files in: "Z:\XXXXX\firebreath\fbbuildwin"
NOTE: The build files in "Z:\XXXXX\firebreath\fbbuildwin" should *NEVER* be modified directly.
When needed, make project changes in cmake files and re-run this script.
Project-specific cmake files are found in [plugin dir]\CMakeLists.txt and
[plugin dir]\Win\projectDef.cmake.
Note that parameters for cmake should be enclosed in double quotes, e.g. "-DVERBOSE=1"
CMAKE parameters:
Z:\XXXXX\firebreath\fbbuildwin>cmake -G "Visual Studio 10" -DFB_PROJECTS_DIR="Z:\dmanpearl On My Mac\pixelmonks\LaasTech\firebreath\projects" "Z:\XXXXX\firebreath\firebreath-dev"
-- Balanced size/speed optimization project dir: Z:/XXXXX/firebreath/projects
-- Looking for include file pthread.h
-- Looking for include file pthread.h - not found
-- Found Threads: TRUE
-- Threads:
-- Looking for include file dlfcn.h
-- Looking for include file dlfcn.h - not found
-- Looking for include file errno.h
-- Looking for include file errno.h - found
-- Looking for include file iconv.h
-- Looking for include file iconv.h - not found
-- Looking for include file limits.h
-- Looking for include file limits.h - found
-- Looking for include file sys/types.h
-- Looking for include file sys/types.h - found
-- Looking for include file sys/socket.h
-- Looking for include file sys/socket.h - not found
-- Looking for include file sys/syscall.h
-- Looking for include file sys/syscall.h - not found
-- Looking for include file sys/time.h
-- Looking for include file sys/time.h - not found
-- Looking for include file sys/timeb.h
-- Looking for include file sys/timeb.h - found
-- Looking for include file sys/stat.h
-- Looking for include file sys/stat.h - found
-- Looking for include file sys/file.h
-- Looking for include file sys/file.h - not found
-- Looking for include file syslog.h
-- Looking for include file syslog.h - not found
-- Looking for include file arpa/inet.h
-- Looking for include file arpa/inet.h - not found
-- Looking for include file netinet/in.h
-- Looking for include file netinet/in.h - not found
-- Looking for include file netinet/tcp.h
-- Looking for include file netinet/tcp.h - not found
-- Looking for include file netdb.h
-- Looking for include file netdb.h - not found
-- Looking for include file unistd.h
-- Looking for include file unistd.h - not found
-- Looking for include file fcntl.h
-- Looking for include file fcntl.h - found
-- Looking for include file stdio.h
-- Looking for include file stdio.h - found
-- Looking for include file stdarg.h
-- Looking for include file stdarg.h - found
-- Looking for include file stdlib.h
-- Looking for include file stdlib.h - found
-- Looking for include file time.h
-- Looking for include file time.h - found
-- Looking for include file wchar.h
-- Looking for include file wchar.h - found
-- Looking for include file inttypes.h
-- Looking for include file inttypes.h - not found
-- Looking for include file memory.h
-- Looking for include file memory.h - found
-- Looking for include file stdint.h
-- Looking for include file stdint.h - found
-- Looking for include file strings.h
-- Looking for include file strings.h - not found
-- Looking for include file string.h
-- Looking for include file string.h - found
-- Looking for 5 include files stdlib.h, ..., float.h
-- Looking for 5 include files stdlib.h, ..., float.h - found
-- Looking for gmtime_r
-- Looking for gmtime_r - not found
-- Looking for localtime_r
-- Looking for localtime_r - not found
-- Looking for gettimeofday
-- Looking for gettimeofday - not found
-- Looking for getpid
-- Looking for getpid - found
-- Looking for ftime
-- Looking for ftime - found
-- Looking for stat
-- Looking for stat - found
-- Looking for lstat
-- Looking for lstat - not found
-- Looking for fcntl
-- Looking for fcntl - not found
-- Looking for lockf
-- Looking for lockf - not found
-- Looking for flock
-- Looking for flock - not found
-- Looking for htons
-- Looking for htons - not found
-- Looking for ntohs
-- Looking for ntohs - not found
-- Looking for htonl
-- Looking for htonl - not found
-- Looking for ntohl
-- Looking for ntohl - not found
-- Looking for vsnprintf
-- Looking for vsnprintf - found
-- Looking for _vsnprintf
-- Looking for _vsnprintf - found
-- Looking for vsprintf_s
-- Looking for vsprintf_s - found
-- Looking for vswprintf_s
-- Looking for vswprintf_s - found
-- Looking for vfprintf_s
-- Looking for vfprintf_s - found
-- Looking for vfwprintf_s
-- Looking for vfwprintf_s - found
-- Looking for _vsnprintf_s
-- Looking for _vsnprintf_s - found
-- Looking for _vsnwprintf_s
-- Looking for _vsnwprintf_s - found
-- Looking for mbstowcs
-- Looking for mbstowcs - found
-- Looking for wcstombs
-- Looking for wcstombs - found
-- Looking for ENAMETOOLONG
-- Looking for ENAMETOOLONG - found
-- Looking for SYS_gettid
-- Looking for SYS_gettid - not found
-- Looking for __FUNCTION__
-- Looking for __FUNCTION__ - found
-- Looking for __PRETTY_FUNCTION__
-- Looking for __PRETTY_FUNCTION__ - not found
-- Looking for __func__
-- Looking for __func__ - not found
-- Performing Test LOG4CPLUS_HAVE___SYNC_ADD_AND_FETCH
-- Performing Test LOG4CPLUS_HAVE___SYNC_ADD_AND_FETCH - Failed
-- Performing Test LOG4CPLUS_HAVE___SYNC_SUB_AND_FETCH
-- Performing Test LOG4CPLUS_HAVE___SYNC_SUB_AND_FETCH - Failed
-- Performing Test LOG4CPLUS_HAVE_GNU_VARIADIC_MACROS
-- Performing Test LOG4CPLUS_HAVE_GNU_VARIADIC_MACROS - Failed
-- Performing Test LOG4CPLUS_HAVE_C99_VARIADIC_MACROS
-- Performing Test LOG4CPLUS_HAVE_C99_VARIADIC_MACROS - Success
-- Looking for clock_gettime
-- Looking for clock_gettime - not found
-- Looking for clock_nanosleep
-- Looking for clock_nanosleep - not found
-- Looking for nanosleep
-- Looking for nanosleep - not found
-- Looking for gethostbyname_r
-- Looking for gethostbyname_r - not found
-- Looking for getaddrinfo
-- Looking for getaddrinfo - not found
-- Performing Test HAVE_ATTRIBUTE_VISIBILITY
-- Performing Test HAVE_ATTRIBUTE_VISIBILITY - Failed
-- Performing Test HAVE_DECLSPEC_DLLEXPORT
-- Performing Test HAVE_DECLSPEC_DLLEXPORT - Success
-- Performing Test HAVE_CXX11_THREAD_LOCAL
-- Performing Test HAVE_CXX11_THREAD_LOCAL - Failed
-- Performing Test HAVE_GCC_THREAD_EXTENSION
-- Performing Test HAVE_GCC_THREAD_EXTENSION - Failed
-- Performing Test HAVE_DECLSPEC_THREAD
-- Performing Test HAVE_DECLSPEC_THREAD - Success
-- Performing Test LOG4CPLUS_HAVE_CXX11_ATOMICS
-- Performing Test LOG4CPLUS_HAVE_CXX11_ATOMICS - Failed
-- Looking for sys/types.h
-- Looking for sys/types.h - found
-- Looking for stddef.h
-- Looking for stddef.h - found
-- Check size of socklen_t
-- Check size of socklen_t - failed
Adding library log4cplus
Generating plugin configuration files in Z:/XXXXX/firebreath/fbbuildwin/projects/LaasTech/gen
-- Configuring done
-- Generating done
-- Build files have been written to: Z:/XXXXX/firebreath/fbbuildwin
My Environment:
I am currently building my plugin on Mac and Windows (Mountain Lion and Windows 8).
I am testing in the following browsers:
Mac: Safari & Chrome.
Windows: IE 10 and Chrome.
FWIW: My Win installation for development is in a Mac VMWare Fusion v5.0 Guest.
Summary:
Please help me get Log4cplus working in my plugin with an accessible log file.

Answer 1

It looks like you're on the right track, but you're missing a very important piece -- you can't write to C:\logs, since only an admin has permissions to do that.
As to the "not found" "errors", those aren't errors... just status messages. That's part of building log4cplus, it's looking to see what your platform supports. You can safely ignore those.
If you look on the Tips and Tricks page you'll find some useful examples.
The main one I'm referring to comes from a gist I created some time back; you'll need to add_boost_library(filesystem) but you can then use this code to find a valid location to put your logs in. The code currently detects if the log path (which will be in %AppData%\LocalLow\CompanyName\logs with this code) exists and only writes the log if it does. It also uses a timestamp and a process id to ensure uniqueness to plugin instance.
#include <boost/filesystem.hpp>
#include "SystemHelpers.h"
using namespace boost::filesystem;
/// ...
void getLoggingMethods( FB::Log::LogMethodList& outMethods )
{
path appDataPath = FB::System::getLocalAppDataPath("CompanyName");
path logDirPath = appDataPath / "logs";
if (exists(logDirPath) && is_directory(logDirPath)) {
std::stringstream ss;
time_t seconds = time(NULL);
boost::thread::id threadId = boost::this_thread::get_id();
ss << seconds << "_" << threadId << ".log";
path logPath = logDirPath / ss.str();
fprintf(stderr, "logging to %s", logPath.string().c_str());
outMethods.push_back(std::make_pair(FB::Log::LogMethod_File, logPath.string()));
}
#ifndef NDEBUG
outMethods.push_back(std::make_pair(FB::Log::LogMethod_Console, std::string()));
#endif
}
// ...