System.cpp

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/***********************************************************************************\
* (c) Copyright 1998-2026 CERN for the benefit of the LHCb and ATLAS collaborations *
*                                                                                   *
* This software is distributed under the terms of the Apache version 2 licence,     *
* copied verbatim in the file "LICENSE".                                            *
*                                                                                   *
* In applying this licence, CERN does not waive the privileges and immunities       *
* granted to it by virtue of its status as an Intergovernmental Organization        *
* or submit itself to any jurisdiction.                                             *
\***********************************************************************************/
#include <GaudiKernel/System.h>
#include <algorithm>
#include <array>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <memory>
#include <regex>
#include <sstream>
#include <typeinfo>
 
// Platform specific include(s):
#ifdef __linux__
#  include "Platform/SystemLinux.h"
#elif defined( __APPLE__ )
#  include "Platform/SystemMacOS.h"
#endif
 
#include <cstdio>
#include <cxxabi.h>
#include <errno.h>
#include <libgen.h>
#include <string.h>
#include <sys/times.h>
#include <unistd.h>
#if defined( __linux ) || defined( __APPLE__ )
#  include <dlfcn.h>
#  include <sys/utsname.h>
#  include <unistd.h>
#elif __hpux
#  include <dl.h>
struct HMODULE {
  shl_descriptor dsc;
  long           numSym;
  shl_symbol*    sym;
};
#endif // HPUX or not...
 
#ifdef __APPLE__
static const std::array<const char*, 2> SHLIB_SUFFIXES = { ".dylib", ".so" };
#else
static const std::array<const char*, 1> SHLIB_SUFFIXES = { ".so" };
#endif // __APPLE__
 
static unsigned long doLoad( const std::string& name, System::ImageHandle* handle ) {
  const char* path = name.c_str();
#if defined( __linux )
  void* mh = ::dlopen( name.length() == 0 ? nullptr : path, RTLD_LAZY | RTLD_GLOBAL );
  *handle  = mh;
#elif defined( __APPLE__ )
  void* mh = ::dlopen( name.length() == 0 ? nullptr : path, RTLD_LAZY | RTLD_GLOBAL );
  *handle  = mh;
#elif __hpux
  shl_t    mh  = ::shl_load( name.length() == 0 ? 0 : path, BIND_IMMEDIATE | BIND_VERBOSE, 0 );
  HMODULE* mod = new HMODULE;
  if ( 0 != mh ) {
    if ( 0 != ::shl_gethandle_r( mh, &mod->dsc ) ) {
      std::cout << "System::loadDynamicLib>" << ::strerror( getLastError() ) << std::endl;
    } else {
      typedef void* ( *___all )();
      ___all _alloc = (___all)malloc;
      mod->numSym   = ::shl_getsymbols( mod->dsc.handle, TYPE_PROCEDURE, EXPORT_SYMBOLS, malloc, &mod->sym );
      *handle       = mod;
    }
  }
#endif
  if ( !*handle ) { return System::getLastError(); }
  return 1;
}
 
static unsigned long loadWithoutEnvironment( const std::string& name, System::ImageHandle* handle ) {
 
  // If the name is empty, don't do anything complicated.
  if ( name.length() == 0 ) { return doLoad( name, handle ); }
 
  // Check if the specified name has a shared library suffix already. If it
  // does, don't bother the name any more.
  std::string dllName        = name;
  bool        hasShlibSuffix = false;
  for ( const char* suffix : SHLIB_SUFFIXES ) {
    const size_t len = strlen( suffix );
    if ( dllName.compare( dllName.length() - len, len, suffix ) == 0 ) {
      hasShlibSuffix = true;
      break;
    }
  }
 
  // If it doesn't have a shared library suffix on it, add the "default" shared
  // library suffix to the name.
  if ( !hasShlibSuffix ) { dllName += SHLIB_SUFFIXES[0]; }
 
  // Load the library.
  return doLoad( dllName, handle );
}

unsigned long System::loadDynamicLib( const std::string& name, ImageHandle* handle ) {
  unsigned long res = 0;
  // if name is empty, just load it
  if ( name.length() == 0 ) {
    res = loadWithoutEnvironment( name, handle );
  } else {
    // If the name is a logical name (environment variable), the try
    // to load the corresponding library from there.
    std::string imgName;
    if ( getEnv( name, imgName ) ) {
      res = loadWithoutEnvironment( imgName, handle );
    } else {
      // build the dll name
      std::string dllName = name;
// Add a possible "lib" prefix to the name on unix platforms. But only if
// it's not an absolute path name.
#if defined( __linux ) || defined( __APPLE__ )
      if ( ( dllName.find( '/' ) == std::string::npos ) && ( dllName.compare( 0, 3, "lib" ) != 0 ) ) {
        dllName = "lib" + dllName;
      }
#endif // unix
      // Now try loading the library with all possible suffixes supported by the
      // platform.
      for ( const char* suffix : SHLIB_SUFFIXES ) {
        // Add the suffix if necessary.
        std::string  libName = dllName;
        const size_t len     = strlen( suffix );
        if ( dllName.compare( dllName.length() - len, len, suffix ) != 0 ) { libName += suffix; }
        // Try to load the library.
        res = loadWithoutEnvironment( libName, handle );
        // If the load succeeded, stop here.
        if ( res == 1 ) { break; }
      }
    }
    if ( res != 1 ) {
#if defined( __linux ) || defined( __APPLE__ )
      errno = 0xAFFEDEAD;
#endif
      // std::cout << "System::loadDynamicLib>" << getLastErrorString() << std::endl;
    }
  }
  return res;
}

unsigned long System::unloadDynamicLib( ImageHandle handle ) {
#if defined( __linux ) || defined( __APPLE__ )
  ::dlclose( handle );
  if ( 0 ) {
#elif __hpux
  // On HP we have to run finalization ourselves.....
  Creator pFinalize = 0;
  if ( getProcedureByName( handle, "_fini", &pFinalize ) ) { pFinalize(); }
  HMODULE* mod = (HMODULE*)handle;
  if ( 0 == ::shl_unload( mod->dsc.handle ) ) {
    delete mod;
  } else {
#else
  if ( false ) {
#endif
    return getLastError();
  }
  return 1;
}

unsigned long System::getProcedureByName( ImageHandle handle, const std::string& name, EntryPoint* pFunction ) {
#if defined( __linux )
  *pFunction = reinterpret_cast<EntryPoint>( ::dlsym( handle, name.c_str() ) );
  if ( !*pFunction ) {
    errno = 0xAFFEDEAD;
    // std::cout << "System::getProcedureByName>" << getLastErrorString() << std::endl;
    return 0;
  }
  return 1;
#elif defined( __APPLE__ )
  *pFunction = ( EntryPoint )::dlsym( handle, name.c_str() );
  if ( !( *pFunction ) ) {
    // Try with an underscore :
    std::string sname = "_" + name;
    *pFunction        = ( EntryPoint )::dlsym( handle, sname.c_str() );
  }
  if ( 0 == *pFunction ) {
    errno = 0xAFFEDEAD;
    std::cout << "System::getProcedureByName>" << getLastErrorString() << std::endl;
    // std::cout << "System::getProcedureByName> failure" << std::endl;
    return 0;
  }
  return 1;
#elif __hpux
  HMODULE* mod = (HMODULE*)handle;
  if ( 0 != mod ) {
    long ll1 = name.length();
    for ( int i = 0; i < mod->numSym; i++ ) {
      long ll2 = strlen( mod->sym[i].name );
      if ( 0 != ::strncmp( mod->sym[i].name, name.c_str(), ( ll1 > ll2 ) ? ll1 : ll2 ) == 0 ) {
        *pFunction = (EntryPoint)mod->sym[i].value;
        return 1;
      }
    }
  }
  return 0;
#else
  return 0;
#endif
}

unsigned long System::getProcedureByName( ImageHandle handle, const std::string& name, Creator* pFunction ) {
  return getProcedureByName( handle, name, (EntryPoint*)pFunction );
}

unsigned long System::getLastError() {
  // convert errno (int) to unsigned long
  return static_cast<unsigned long>( static_cast<unsigned int>( errno ) );
}

const std::string System::getLastErrorString() {
  const std::string errString = getErrorString( getLastError() );
  return errString;
}

const std::string System::getErrorString( unsigned long error ) {
  std::string errString = "";
  char*       cerrString( nullptr );
  // Remember: for linux dl* routines must be handled differently!
  if ( error == 0xAFFEDEAD ) {
    cerrString = ::dlerror();
    if ( !cerrString ) cerrString = ::strerror( error );
    if ( !cerrString ) {
      cerrString = (char*)"Unknown error. No information found in strerror()!";
    } else {
      errString = std::string( cerrString );
    }
    errno = 0;
  } else {
    cerrString = ::strerror( error );
    errString  = std::string( cerrString );
  }
  return errString;
}
 
const std::string System::typeinfoName( const std::type_info& tinfo ) { return typeinfoName( tinfo.name() ); }
 
const std::string System::typeinfoName( const char* class_name ) { return Platform::typeinfoName( class_name ); }

const std::string& System::hostName() {
  static const std::string host = Platform::hostName();
  return host;
}

const std::string& System::osName() {
  static const std::string osname = Platform::osName();
  return osname;
}

const std::string& System::osVersion() {
  static const std::string osver = Platform::osVersion();
  return osver;
}

const std::string& System::machineType() {
  static const std::string mach = Platform::machineType();
  return mach;
}

const std::string& System::accountName() {
  static const std::string account = Platform::accountName();
  return account;
}

long System::numCmdLineArgs() { return cmdLineArgs().size(); }

long System::argc() { return cmdLineArgs().size(); }

const std::vector<std::string> System::cmdLineArgs() {
  static const std::vector<std::string> args = Platform::cmdLineArgs();
  return args;
}

char** System::argv() {
  auto helperFunc = []( const std::vector<std::string>& args ) -> std::vector<const char*> {
    std::vector<const char*> result;
    std::transform( args.begin(), args.end(), std::back_inserter( result ),
                    []( const std::string& s ) { return s.c_str(); } );
    return result;
  };
  static const std::vector<const char*> args = helperFunc( cmdLineArgs() );
  // We rely here on the fact that a vector's allocation table is contiguous
  return (char**)&( args[0] );
}

std::string System::getEnv( const char* var ) {
  char* env;
  if ( ( env = getenv( var ) ) != nullptr ) {
    return env;
  } else {
    return "UNKNOWN";
  }
}

bool System::getEnv( const char* var, std::string& value ) {
  char* env;
  if ( ( env = getenv( var ) ) != nullptr ) {
    value = env;
    return true;
  } else {
    return false;
  }
}
 
bool System::isEnvSet( const char* var ) { return getenv( var ) != nullptr; }

#if defined( __APPLE__ )
// Needed for _NSGetEnviron(void)
#  include <crt_externs.h>
#endif
std::vector<std::string> System::getEnv() {
#if defined( __APPLE__ )
  static char** environ = *_NSGetEnviron();
#endif
  std::vector<std::string> vars;
  for ( int i = 0; environ[i] != nullptr; ++i ) { vars.push_back( environ[i] ); }
  return vars;
}
 
// -----------------------------------------------------------------------------
// backtrace utilities
// -----------------------------------------------------------------------------
#if defined( __linux ) || defined( __APPLE__ )
#  include <execinfo.h>
#endif
 
int System::backTrace( [[maybe_unused]] void** addresses, [[maybe_unused]] const int depth ) {
 
#if defined( __linux ) || defined( __APPLE__ )
 
  int count = backtrace( addresses, depth );
  return count > 0 ? count : 0;
 
#else
  return 0;
#endif
}
 
bool System::backTrace( std::string& btrace, const int depth, const int offset ) {
  try {
    // Always hide the first two levels of the stack trace (that's us)
    const size_t totalOffset = offset + 2;
    const size_t totalDepth  = depth + totalOffset;
 
    std::string fnc, lib;
 
    std::vector<void*> addresses( totalDepth, nullptr );
    const size_t       count = System::backTrace( addresses.data(), totalDepth );
    for ( size_t i = totalOffset; i < count; ++i ) {
      void* addr = nullptr;
 
      if ( System::getStackLevel( addresses[i], addr, fnc, lib ) ) {
        std::ostringstream ost;
        ost << "#" << std::setw( 3 ) << std::setiosflags( std::ios::left ) << i - totalOffset + 1;
        ost << std::hex << addr << std::dec << " " << fnc << "  [" << lib << "]" << std::endl;
        btrace += ost.str();
      }
    }
    return true;
  } catch ( const std::bad_alloc& e ) { return false; }
}
 
bool System::getStackLevel( [[maybe_unused]] void* addresses, [[maybe_unused]] void*& addr,
                            [[maybe_unused]] std::string& fnc, [[maybe_unused]] std::string& lib ) {
 
#if defined( __linux ) || defined( __APPLE__ )
 
  Dl_info info;
 
  if ( dladdr( addresses, &info ) && info.dli_fname && info.dli_fname[0] != '\0' ) {
    const char* symbol = info.dli_sname && info.dli_sname[0] != '\0' ? info.dli_sname : nullptr;
 
    lib  = info.dli_fname;
    addr = info.dli_saddr;
 
    if ( symbol ) {
      int  stat = -1;
      auto dmg =
          std::unique_ptr<char, decltype( free )*>( abi::__cxa_demangle( symbol, nullptr, nullptr, &stat ), std::free );
      fnc = ( stat == 0 ) ? dmg.get() : symbol;
    } else {
      fnc = "local";
    }
    return true;
  } else {
    return false;
  }
 
#else
  return false;
#endif
}

int System::setEnv( const std::string& name, const std::string& value, int overwrite ) {
  return value.empty() ?
                       // remove if set to nothing (and return success)
         ::unsetenv( name.c_str() ),
         0 :
                       // set the value
         ::setenv( name.c_str(), value.c_str(), overwrite );
}