diff --git a/changelog.yaml b/changelog.yaml
index baf1362..210b24a 100644
--- a/changelog.yaml
+++ b/changelog.yaml
@@ -1,4 +1,7 @@
 ---
+- 7.11.9:
+    - Made gdxOpenRead not lock the file (from being deleted) on Windows.
+    - Removed unnecessary dependency on "dladdr" as requested in GitHub issue.
 - 7.11.8:
     - Added C++ port of GDX utilities gdxdiff, gdxdump, and gdxmerge.
 - 7.11.7:
diff --git a/src/gdlib/gmacro.cpp b/src/gdlib/gmacro.cpp
index 0ca08de..981376a 100644
--- a/src/gdlib/gmacro.cpp
+++ b/src/gdlib/gmacro.cpp
@@ -331,6 +331,8 @@ bool TGAMSMacro::Define( const std::string &p, int &LUsed )
    }
    Body.clear();
    LUsed = static_cast<int>( p.length() );
+   // fake trailing blank
+   Rdr.pr.push_back( ' ' );
    return AddToBody( Rdr.pr );
 }
 
@@ -342,8 +344,9 @@ bool TGAMSMacro::AddToBody( const std::string &p )
 
    TPWriter Wrt;
    Wrt.StoreStr( Body );
-   const auto L = static_cast<int>( p.length() );
-   const TPReader Rdr { p };
+   //no trailing blank
+   const auto L = static_cast<int>( p.length() ) - 1;
+   const TPReader Rdr { p.substr(0, L) };
    const bool res { Rdr.ChFromEnd( 0 ) == '\\' };
    if( !res ) Wrt.StoreTrimStr( p );
    else
diff --git a/src/gdlib/gmsheapnew.h b/src/gdlib/gmsheapnew.h
index f3b7256..aa5560e 100644
--- a/src/gdlib/gmsheapnew.h
+++ b/src/gdlib/gmsheapnew.h
@@ -139,6 +139,13 @@ class THeapMgr final
       return new(XGetMem<T>()) T {};
    }
 
+   // Use perfect forwarding for arguments to T's constructor
+   template<typename T, typename... Args>
+   inline T *XGetMemCreat( Args &&...args )
+   {
+      return new( XGetMem<T>() ) T( std::forward<Args>( args )... );
+   }
+
    void *XGetMemNC( int Size );
    void *XAllocMem( int Size );
 
diff --git a/src/gdlib/nlcodebase.cpp b/src/gdlib/nlcodebase.cpp
new file mode 100644
index 0000000..3a56449
--- /dev/null
+++ b/src/gdlib/nlcodebase.cpp
@@ -0,0 +1,4 @@
+#include "nlcodebase.h"
+
+namespace gdlib::nlcodebase {
+}
diff --git a/src/gdlib/nlcodebase.h b/src/gdlib/nlcodebase.h
new file mode 100644
index 0000000..357b83c
--- /dev/null
+++ b/src/gdlib/nlcodebase.h
@@ -0,0 +1,10 @@
+#pragma once
+
+namespace gdlib::nlcodebase {
+
+class TNLInstStoreBase {
+public:
+   bool NLCodeEmitted {};
+};
+
+}
\ No newline at end of file
diff --git a/src/gdlib/statlibobj.cpp b/src/gdlib/statlibobj.cpp
index 7fb3860..91138c4 100644
--- a/src/gdlib/statlibobj.cpp
+++ b/src/gdlib/statlibobj.cpp
@@ -56,9 +56,8 @@ static std::string termString;
 
 static bool tmElapsed( uint32_t &thenT, uint32_t minDiffT )
 {
-   auto nowT = rtl::idglobal_p3::GetTickCount();
-   auto diffT = rtl::idglobal_p3::GetTickDiff( thenT, nowT );
-   if( diffT > minDiffT )
+   const auto nowT = rtl::idglobal_p3::GetTickCount();
+   if( const auto diffT = rtl::idglobal_p3::GetTickDiff( thenT, nowT ); diffT > minDiffT )
    {
       thenT = nowT;
       return true;
@@ -76,14 +75,14 @@ static void statuslerror( const std::string &s )
    debugStream << "*** gStatusL." << s << '\n';
 }
 
-bool opentextmsg( FILE *&f, const std::string &fn, gdlib::gmsgen::tfileaction fa, std::string &msg );
+bool opentextmsg( FILE *&f, const std::string &fn, tfileaction fa, std::string &msg );
 
 TGMSLogStream::TGMSLogStream( std::string &Msg ) : FLastShowTicks { rtl::idglobal_p3::GetTickCount() }
 {
    Msg.clear();
 }
 
-void TGMSLogStream::registerWriteCallback( gdlib::stattypes::tgwrite *fptr, void *usermem )
+void TGMSLogStream::registerWriteCallback( stattypes::tgwrite *fptr, void *usermem )
 {
    Fgfcb = fptr;
    Fgfusrmem = usermem;
@@ -110,7 +109,7 @@ void TGMSLogStream::LogClose()
    }
 }
 
-bool TGMSLogStream::LogOpen( int Astat, gdlib::gmsgen::tfileaction AAction, const std::string &Afn )
+bool TGMSLogStream::LogOpen( int Astat, const tfileaction AAction, const std::string &Afn )
 {
    if( FStatus != sl_closed )
    {
@@ -246,13 +245,13 @@ void TGMSLogStream::LogMessage( const std::string &s )
    FLastIsMsg = true;
 }
 
-void TGMSLogStream::LogFileName( const std::string &fn, int Lev )
+void TGMSLogStream::LogFileName( const std::string &fn, const int Lev )
 {
    if( !FLogEnabled ) return;
    if( FhasNewData && FTraceLevel > 0 ) ShowStatLine();
    FFullFileName = fn;
-   FFileName = gdlib::strutilx::ExtractFileNameEx( fn );
-   int OldLevel = FNestLevel;
+   FFileName = strutilx::ExtractFileNameEx( fn );
+   const int OldLevel = FNestLevel;
    FNestLevel = Lev;
    if( !( FNestLevel < OldLevel || FLastIsMsg || FTraceLevel > 2 ) ) FLastIsMsg = true;
    else
@@ -270,7 +269,7 @@ void TGMSLogStream::LogFileName( const std::string &fn, int Lev )
 		std::cout << "--- " << nestpoints << " " << fn << "(" << Lev << ") 0 Mb" << '\n';*/
 }
 
-void TGMSLogStream::LogLineNr( int N )
+void TGMSLogStream::LogLineNr( const int N )
 {
    if( FLogEnabled && N != FLineNr )
    {
@@ -291,11 +290,11 @@ void TGMSLogStream::LogLineNr( int N )
    }
 }
 
-void TGMSLogStream::LogAnchor( int N )
+void TGMSLogStream::LogAnchor( const int N )
 {
    if( FLogEnabled )
    {
-      std::string s = "[LST:"s + rtl::sysutils_p3::IntToStr( N ) + "]"s;
+      const std::string s = "[LST:"s + IntToStr( N ) + "]"s;
       CheckOpen();
       write_gf( s );
       FLenLast += static_cast<int>(s.length());
@@ -312,13 +311,13 @@ void TGMSLogStream::LogTitleAnchor( const std::string &Msg )
    }
 }
 
-void TGMSLogStream::LogFileAnchor( bool err, const std::string &fn, int line, int col )
+void TGMSLogStream::LogFileAnchor( const bool err, const std::string &fn, const int line, const int col )
 {
    if( !FLogEnabled ) return;
    doFileAnchor( err, fn, line, col );
 }
 
-void TGMSLogStream::LogMemory( double M )
+void TGMSLogStream::LogMemory( const double M )
 {
    if( FLogEnabled && std::abs( M - FMemory ) > 0.5 )
    {
@@ -328,7 +327,7 @@ void TGMSLogStream::LogMemory( double M )
    }
 }
 
-void TGMSLogStream::LogErrrorCnt( int N )
+void TGMSLogStream::LogErrrorCnt( const int N )
 {
 
    if( FLogEnabled && N != FErrorCnt )
@@ -348,11 +347,10 @@ void TGMSLogStream::freshenEx()
 {
    if( FLogEnabled && FStatus == sl_output && FTraceLevel > 1 )
    {
-      auto nowT = rtl::idglobal_p3::GetTickCount();
-      auto dt = rtl::idglobal_p3::GetTickDiff( FLineStartTicks, nowT );
+      const auto nowT = rtl::idglobal_p3::GetTickCount();
+      const auto dt = rtl::idglobal_p3::GetTickDiff( FLineStartTicks, nowT );
       FLastShowTicks = nowT;
-      auto secs = dt / 1000;
-      if( secs > 2 && secs > FPrevSecs && ( secs <= 30 || secs - 5 >= FPrevSecs ) )
+      if( const auto secs = dt / 1000; secs > 2 && secs > FPrevSecs && ( secs <= 30 || secs - 5 >= FPrevSecs ) )
       {
          FPrevSecs = secs;
          FhasNewData = true;
@@ -365,7 +363,7 @@ void TGMSLogStream::freshenEx()
    }
 }
 
-void TGMSLogStream::LogDumpFilename( const std::string &prfx, bool enabled, const std::string &what, const std::string &gs, gdlib::gmsgen::tfileaction fa, int ioResOrNeg )
+void TGMSLogStream::LogDumpFilename( const std::string &prfx, const bool enabled, const std::string &what, const std::string &gs, const tfileaction fa, const int ioResOrNeg )
 {
    if( !enabled || !FLogEnabled ) return;
    std::string s { prfx + " "s + what + " "s };
@@ -382,7 +380,7 @@ void TGMSLogStream::LogDumpFilename( const std::string &prfx, bool enabled, cons
          break;
    }
 
-   s += "="s + rtl::sysutils_p3::IntToStr( ioResOrNeg ) + " FN=\""s + gs + "\""s;
+   s += "="s + IntToStr( ioResOrNeg ) + " FN=\""s + gs + "\""s;
    LogMessage( s );
    if( ioResOrNeg > 0 )
       LogMessage( prfx + "MSG=" + SysErrorMessage( ioResOrNeg ) );
@@ -405,7 +403,7 @@ void TGMSLogStream::LogWriteLn( const std::string &s )
 
 void TGMSLogStream::LogWrite( const std::string &p )
 {
-   const int blockSize = 255;
+   constexpr int blockSize = 255;
    if( p.empty() || !FLogEnabled ) return;
    if( !Fgfcb ) gstatStartWriting();
    const int numBlocks = static_cast<int>( std::ceil( static_cast<double>( p.length() ) / static_cast<double>( blockSize ) ) );
@@ -417,7 +415,7 @@ void TGMSLogStream::LogWrite( const std::string &p )
    if( !Fgfcb ) std::fflush(Ffcon);;
 }
 
-void TGMSLogStream::LogWritePlain( const std::string &s )
+void TGMSLogStream::LogWritePlain( const std::string &s ) const
 {
    if( !FLogEnabled ) return;
    std::fwrite( s.c_str(), sizeof( char ), s.size(), Ffcon );
@@ -430,14 +428,14 @@ void TGMSLogStream::showCounts()
 {
 #ifdef METER
    LogMessage( "DEBUG: TGMSLogStream usage counts:" );
-   LogMessage( "  method LogLineNr: " + rtl::sysutils_p3::IntToStr( cntLogLineNr ) );
-   LogMessage( "  method LogMemory: " + rtl::sysutils_p3::IntToStr( cntLogMemory ) );
-   LogMessage( "  method   freshen: " + rtl::sysutils_p3::IntToStr( cntFreshen ) );
+   LogMessage( "  method LogLineNr: " + IntToStr( cntLogLineNr ) );
+   LogMessage( "  method LogMemory: " + IntToStr( cntLogMemory ) );
+   LogMessage( "  method   freshen: " + IntToStr( cntFreshen ) );
    LogMessage( "" );
 #endif
 }
 
-void TGMSLogStream::setIDErun( bool v )
+void TGMSLogStream::setIDErun( const bool v )
 {
    FIDE = v;
 }
@@ -447,7 +445,7 @@ bool TGMSLogStream::getLogEnabled() const
    return FLogEnabled;
 }
 
-void TGMSLogStream::setLogEnabled( bool v )
+void TGMSLogStream::setLogEnabled( const bool v )
 {
    FLogEnabled = v;
 }
@@ -457,7 +455,7 @@ int TGMSLogStream::getTraceLevel() const
    return FTraceLevel;
 }
 
-void TGMSLogStream::setTraceLevel( int v )
+void TGMSLogStream::setTraceLevel( const int v )
 {
    FTraceLevel = v;
 }
@@ -470,18 +468,18 @@ std::string TGMSLogStream::getRedirFilename() const
 std::string TGMSLogStream::getRedirString() const
 {
    if( FRedirFileName.empty() ) return ""s;
-   std::string pf = FSaveAstat == 4 ? " | tee -a " : " >> ";
+   const std::string pf = FSaveAstat == 4 ? " | tee -a " : " >> ";
    return pf + getRedirFilename();
 }
 
-std::string TGMSLogStream::getShortRedirString( const std::string &Dir )
+std::string TGMSLogStream::getShortRedirString( const std::string &Dir ) const
 {
    if( FRedirFileName.empty() ) return ""s;
-   auto k { Dir.find( FRedirFileName ) };
+   const auto k { Dir.find( FRedirFileName ) };
    return k == std::string::npos ? getRedirString() : " >> \"." + FRedirFileName.substr( Dir.length() ) + "\"";
 }
 
-void TGMSLogStream::SetOSMemory( int v )
+void TGMSLogStream::SetOSMemory( const int v )
 {
    FShowOSMem = v;
 }
@@ -492,7 +490,8 @@ void TGMSLogStream::CheckOpen()
    {
       Ffcon = stdout;//&debugStream;// new std::fstream("", std::ios_base::out);
       //debugStream << "*** Log reopened as output\n";
-      fwrite( "*** Log reopened as output\n", sizeof( char ), 27, Ffcon );
+      const auto msg {"*** Log reopened as output\n"};
+      std::fwrite( msg, sizeof( char ), 27, Ffcon );
       FStatus = sl_output;
    }
 }
@@ -510,10 +509,10 @@ void TGMSLogStream::Flush()
    FLastIsMsg = false;
 }
 
-void TGMSLogStream::doFileAnchor( bool err, const std::string &fn, int line, int col )
+void TGMSLogStream::doFileAnchor( const bool err, const std::string &fn, const int line, const int col )
 {
    CheckOpen();
-   std::string s { ( err ? "[ERR:"s : "[FIL:"s ) + "\"" + fn + "\"," + rtl::sysutils_p3::IntToStr( line ) + "," + rtl::sysutils_p3::IntToStr( col ) + "]" };
+   const std::string s { ( err ? "[ERR:"s : "[FIL:"s ) + "\""s + fn + "\","s + IntToStr( line ) + ","s + IntToStr( col ) + "]"s };
    write_gf( s );
    FLenLast += static_cast<int>(s.length());
 }
@@ -545,10 +544,11 @@ void TGMSLogStream::ShowStatLine()
       if( FNestLevel > 0 )
          s += std::string( FNestLevel, '.' ) + " "s;
       s += FFileName + "("s + IntToStr( FLineNr ) + ")"s;
-      uint64_t rss, vss;
-      if( FShowOSMem == 1 && rtl::p3utils::p3GetMemoryInfo( rss, vss ) ) FMemory = (double) rss / 1e6;
+      uint64_t vss;
+      if( uint64_t rss; FShowOSMem == 1 && rtl::p3utils::p3GetMemoryInfo( rss, vss ) )
+         FMemory = static_cast<double>( rss ) / 1e6;
       else if( FShowOSMem == 2 && rtl::p3utils::p3GetMemoryInfo( rss, vss ) )
-         FMemory = (double) vss / 1e6;
+         FMemory = static_cast<double>( vss ) / 1e6;
       s += " "s + IntToStr( utils::round<int>( FMemory ) ) + " Mb"s;
       if( FErrorCnt > 0 )
       {
@@ -558,7 +558,7 @@ void TGMSLogStream::ShowStatLine()
       if( FSpinChar != ' ' ) s += " "s + FSpinChar;
       if( FPrevSecs > 0 ) s += " " + IntToStr( FPrevSecs ) + " secs";
       if( FLenLast > 0 ) write_gf( "\r" );
-      if( (int) s.length() < FLenLast )
+      if( static_cast<int>( s.length() ) < FLenLast )
       {
          write_gf( std::string( FLenLast, ' ' ) + "\r" );
       }
@@ -576,15 +576,15 @@ void TGMSLogStream::gstatStartWriting()
    Flush();
 }
 
-void TGMSLogStream::writeln_gf( const std::string &msg )
+void TGMSLogStream::writeln_gf( const std::string &msg ) const
 {
    write_gf( msg + termString);
 }
 
 
-void TGMSLogStream::write_gf( const std::string &msg )
+void TGMSLogStream::write_gf( const std::string &msg ) const
 {
-   if( Fgfcb ) ( *Fgfcb )( msg, gdlib::stattypes::doLog, Fgfusrmem );
+   if( Fgfcb ) ( *Fgfcb )( msg, stattypes::doLog, Fgfusrmem );
    else
    {
       std::fwrite( msg.c_str(), sizeof( char ), msg.size(), Ffcon );
@@ -592,7 +592,7 @@ void TGMSLogStream::write_gf( const std::string &msg )
    }
 }
 
-void TGMSLogStream::writeln_gf(const char* msg)
+void TGMSLogStream::writeln_gf(const char* msg ) const
 {
    static std::array<char, 256> ss;
    const auto l { std::strlen( msg ) };
@@ -601,8 +601,9 @@ void TGMSLogStream::writeln_gf(const char* msg)
    write_gf( ss.data() );
 }
 
-void TGMSLogStream::write_gf(const char* msg) {
-   if( Fgfcb ) ( *Fgfcb )( msg, gdlib::stattypes::doLog, Fgfusrmem );
+void TGMSLogStream::write_gf(const char* msg ) const
+{
+   if( Fgfcb ) ( *Fgfcb )( msg, stattypes::doLog, Fgfusrmem );
    else
    {
       fwrite( msg, sizeof( char ), std::strlen(msg), Ffcon );
@@ -610,12 +611,12 @@ void TGMSLogStream::write_gf(const char* msg) {
    }
 }
 
-void TGMSStatusStream::writeln_gf( const std::string &msg )
+void TGMSStatusStream::writeln_gf( const std::string &msg ) const
 {
    write_gf( msg + termString );
 }
 
-void TGMSStatusStream::write_gf( const std::string &msg )
+void TGMSStatusStream::write_gf( const std::string &msg ) const
 {
    if( Fgfcb ) ( *Fgfcb )( msg, gdlib::stattypes::doStat, Fgfusrmem );
    else fwrite( msg.c_str(), sizeof( char ), msg.size(), Ffstat );
@@ -654,9 +655,10 @@ trcerrtxt TGMSStatusStream::SolverErrorMessage( const std::string &s )
 
 void TGMSStatusStream::SolverErrorAdd( int rownum, int columnnum, const std::string &msg )
 {
-   trcerrrec ehdrptr { Ffrsteqptr }, nextrc { ehdrptr };
+   const trcerrrec ehdrptr { Ffrsteqptr };
+   trcerrrec nextrc { ehdrptr };
    bool firsttime { true };
-   trcerrtxt newerr { SolverErrorMessage( msg ) };
+   const trcerrtxt newerr { SolverErrorMessage( msg ) };
 
    while( rownum > nextrc->seqno )// find row
       nextrc = nextrc->tnxtrc;
@@ -671,11 +673,11 @@ void TGMSStatusStream::SolverErrorAdd( int rownum, int columnnum, const std::str
 
    if( firsttime )
    {// first time on this equ/var
-      auto newtyp = new rcerrtyp {
+      const auto newtyp = new rcerrtyp {
               1,
               nullptr,
               newerr };
-      auto newrc = new rcerrrec {
+      const auto newrc = new rcerrrec {
               nextrc->seqno,
               nextrc->colnum,
               nextrc->tnxtrc,
@@ -702,7 +704,7 @@ void TGMSStatusStream::SolverErrorAdd( int rownum, int columnnum, const std::str
       }
       if( firsttime )
       {
-         auto newtyp = new rcerrtyp {
+         const auto newtyp = new rcerrtyp {
                  1,
                  nextrc->tfrsttyp,
                  newerr };
@@ -747,7 +749,7 @@ TGMSStatusStream::~TGMSStatusStream()
    }
 }
 
-void TGMSStatusStream::registerWriteCallback( gdlib::stattypes::tgwrite *fptr, void *usermem )
+void TGMSStatusStream::registerWriteCallback( stattypes::tgwrite *fptr, void *usermem )
 {
    Fgfcb = fptr;
    Fgfusrmem = usermem;
@@ -802,7 +804,7 @@ void TGMSStatusStream::StatusDumpFirst()
    Fmsgbufcount = 0;
 }
 
-bool TGMSStatusStream::StatusAppend( const std::string &fn, std::string &msg )
+bool TGMSStatusStream::StatusAppend( const std::string &fn, std::string &msg ) const
 {
    if( !Fstatusopen )
    {
@@ -912,8 +914,8 @@ bool TGMSStatusStream::StatusDumpNext( std::string &msg )
       {
          case 'B':
          {
-            std::string fnsys = utils::trim( msg.substr( 2 ) ), s;
-            if( !opentextmsg( Ffsysout, fnsys, gmsgen::forRead, s ) )
+            const std::string fnsys = utils::trim( msg.substr( 2 ) );
+            if( std::string s; !opentextmsg( Ffsysout, fnsys, forRead, s ) )
             {
                Fmsgbuf.front() = "Msg=" + s;
                Fmsgbuf[1] = "Could not process above statement";
@@ -939,10 +941,10 @@ bool TGMSStatusStream::StatusDumpNext( std::string &msg )
    return true;
 }
 
-bool TGMSStatusStream::StatusProcessNext( gdlib::stattypes::tstatusproc &statusproc, std::string &msg1, std::string &msg2, int &num )
+bool TGMSStatusStream::StatusProcessNext( stattypes::tstatusproc &statusproc, std::string &msg1, std::string &msg2, int &num )
 {
    int VarNum, EquNum, p;
-   std::string line, s;
+   std::string s;
 
    if( Fmsgbufcount > 0 )
    {
@@ -968,21 +970,18 @@ bool TGMSStatusStream::StatusProcessNext( gdlib::stattypes::tstatusproc &statusp
    {
       statusproc = stattypes::statusLine;
       assert(Ffsysout);
-      if( !feof(Ffsysout) )
+      if( !feof( Ffsysout ) )
       {
          msg1 = utils::getline( Ffsysout );
          return true;
       }
-      else
-      {
-         Fcopysysout = false;
-         std::fclose(Ffsysout);
-      }
+      Fcopysysout = false;
+      std::fclose( Ffsysout );
    }
 
    while( !feof(Ffstat) )
    {
-      line = utils::getline( Ffstat );
+      std::string line = utils::getline( Ffstat );
       msg1.clear();
       msg2.clear();
       num = 0;
@@ -1221,8 +1220,7 @@ bool TGMSStatusStream::StatusErrorNextEqu( int &row )
       if( !Fnextheader || Fnextheader->seqno == std::numeric_limits<int>::max() )
          return false;
       row = Fnextheader->seqno;
-      int col = Fnextheader->colnum;
-      if( !row || col ) Fnextheader = Fnextheader->tnxtrc;
+      if( const int col = Fnextheader->colnum; !row || col ) Fnextheader = Fnextheader->tnxtrc;
       else
       {
          Fnexterror = Fnextheader->tfrsttyp;
@@ -1240,7 +1238,7 @@ bool TGMSStatusStream::StatusErrorNextVar( int &col )
    while( true )
    {
       if( !Fnextheader || Fnextheader->seqno == std::numeric_limits<int>::max() ) return false;
-      int row = Fnextheader->seqno;
+      const int row = Fnextheader->seqno;
       col = Fnextheader->colnum;
       if( !col || row ) Fnextheader = Fnextheader->tnxtrc;
       else
@@ -1300,12 +1298,12 @@ void TGMSStatusStream::StatusClose()
    }
 }
 
-bool TGMSStatusStream::StatusFileOpen( gdlib::gmsgen::tfileaction AAction, std::string &msg )
+bool TGMSStatusStream::StatusFileOpen( const tfileaction AAction, std::string &msg )
 {
    if( checkfile(msg) )
       msg.clear();
    else return false;
-   // shouldnt this be binary mode on windows?
+   // shouldn't this be binary mode on windows?
    Ffstat = fopen( Ffnstat.c_str(), "r" );
    bool newstat;
    if(Ffstat) {
@@ -1337,7 +1335,7 @@ bool TGMSStatusStream::StatusFileOpen( gdlib::gmsgen::tfileaction AAction, std::
    // TODO: Implement me!
 }
 
-void TGMSStatusStream::StatusWriteLn( const std::string &s )
+void TGMSStatusStream::StatusWriteLn( const std::string &s ) const
 {
    try
    {
@@ -1349,63 +1347,63 @@ void TGMSStatusStream::StatusWriteLn( const std::string &s )
    }
 }
 
-void TGMSStatusStream::StatusWrite( const std::string &p )
+void TGMSStatusStream::StatusWrite( const std::string &p ) const
 {
    if( p.empty() ) return;
    write_gf( p );
 }
 
-void TGMSStatusStream::StatusWritePlain( const std::string &s )
+void TGMSStatusStream::StatusWritePlain( const std::string &s ) const
 {
    fwrite( s.c_str(), sizeof( char ), s.size(), Ffstat );
 }
 
-void TGMSStatusStream::StatusTerminationRequestfromSolver()
+void TGMSStatusStream::StatusTerminationRequestfromSolver() const
 {
    commonStatusFunc( "TerminationRequestfromSolver", "StatusTerminationRequestfromSolver" )( "" );
 }
 
-void TGMSStatusStream::StatusCopyOn()
+void TGMSStatusStream::StatusCopyOn() const
 {
    commonStatusFunc( "1", "StatusCopyOn" )( "" );
 }
 
-void TGMSStatusStream::StatusCopyOff()
+void TGMSStatusStream::StatusCopyOff() const
 {
    commonStatusFunc( "2", "StatusCopyOff" )( "" );
 }
 
-void TGMSStatusStream::StatusLSTAnchor( const std::string &s )
+void TGMSStatusStream::StatusLSTAnchor( const std::string &s ) const
 {
    commonStatusFunc( "L", "StatusLSTAnchor" )( s );
 }
 
-void TGMSStatusStream::StatusCopyLine( const std::string &s )
+void TGMSStatusStream::StatusCopyLine( const std::string &s ) const
 {
    commonStatusFunc( "C", "StatusCopyLine" )( s );
 }
 
-void TGMSStatusStream::StatusCopyFile( const std::string &s )
+void TGMSStatusStream::StatusCopyFile( const std::string &s ) const
 {
    commonStatusFunc( "A", "StatusCopyFile" )( s );
 }
 
-void TGMSStatusStream::StatusCopyFileOnSysOut( const std::string &s )
+void TGMSStatusStream::StatusCopyFileOnSysOut( const std::string &s ) const
 {
    commonStatusFunc( "B", "StatusCopyFileOnSysOut" )( s );
 }
 
-void TGMSStatusStream::StatusEndOfFile()
+void TGMSStatusStream::StatusEndOfFile() const
 {
    commonStatusFunc( "3", "StatusEndOfFile" )( "" );
 }
 
-void TGMSStatusStream::StatusSysOut()
+void TGMSStatusStream::StatusSysOut() const
 {
    commonStatusFunc( "4", "StatusSysOut" )( "" );
 }
 
-void TGMSStatusStream::StatusPageEject()
+void TGMSStatusStream::StatusPageEject() const
 {
    commonStatusFunc( "8", "StatusPageEject" )( "" );
 }
@@ -1423,7 +1421,7 @@ void TGMSStatusStream::StatusSetEditSymbol( char c )
    }
 }
 
-void TGMSStatusStream::StatusAuditLine( const std::string &s )
+void TGMSStatusStream::StatusAuditLine( const std::string &s ) const
 {
    try
    {
@@ -1436,11 +1434,11 @@ void TGMSStatusStream::StatusAuditLine( const std::string &s )
    }
 }
 
-void TGMSStatusStream::StatusEquationName( const std::string &s1, int num, std::string &s2 )
+void TGMSStatusStream::StatusEquationName( const std::string &s1, const int num, const std::string &s2 ) const
 {
    try
    {
-      writeln_gf( ""s + Feditsymbol + "E \""s + s1 + "\" "s + rtl::sysutils_p3::IntToStr( num ) + " \""s + s2 + "\""s );
+      writeln_gf( ""s + Feditsymbol + "E \""s + s1 + "\" "s + IntToStr( num ) + " \""s + s2 + "\""s );
    }
    catch( ... )
    {
@@ -1448,11 +1446,11 @@ void TGMSStatusStream::StatusEquationName( const std::string &s1, int num, std::
    }
 }
 
-void TGMSStatusStream::StatusVariableName( const std::string &s1, int num, const std::string &s2 )
+void TGMSStatusStream::StatusVariableName( const std::string &s1, const int num, const std::string &s2 ) const
 {
    try
    {
-      writeln_gf( ""s + Feditsymbol + "V \""s + s1 + "\" "s + rtl::sysutils_p3::IntToStr( num ) + " \""s + s2 + "\""s );
+      writeln_gf( ""s + Feditsymbol + "V \""s + s1 + "\" "s + IntToStr( num ) + " \""s + s2 + "\""s );
    }
    catch( ... )
    {
@@ -1460,21 +1458,21 @@ void TGMSStatusStream::StatusVariableName( const std::string &s1, int num, const
    }
 }
 
-void TGMSStatusStream::StatusEquationError( int num, const std::string &s )
+void TGMSStatusStream::StatusEquationError( const int num, const std::string &s ) const
 {
-   commonStatusFunc( "5 "s + rtl::sysutils_p3::IntToStr( num ) + " "s, "StatusEquationError"s )( s );
+   commonStatusFunc( "5 "s + IntToStr( num ) + " "s, "StatusEquationError"s )( s );
 }
 
-void TGMSStatusStream::StatusVariableError( int num, const std::string &s )
+void TGMSStatusStream::StatusVariableError( const int num, const std::string &s ) const
 {
-   commonStatusFunc( "6 " + rtl::sysutils_p3::IntToStr( num ) + " "s, "StatusVariableError" )( s );
+   commonStatusFunc( "6 " + IntToStr( num ) + " "s, "StatusVariableError" )( s );
 }
 
-void TGMSStatusStream::StatusJacobianError( int num1, int num2, const std::string &s )
+void TGMSStatusStream::StatusJacobianError( const int num1, const int num2, const std::string &s ) const
 {
    try
    {
-      writeln_gf( ""s + Feditsymbol + "7 " + rtl::sysutils_p3::IntToStr( num1 ) + " " + rtl::sysutils_p3::IntToStr( num2 ) + " " + s );
+      writeln_gf( ""s + Feditsymbol + "7 "s + IntToStr( num1 ) + ' ' + IntToStr( num2 ) + ' ' + s );
    }
    catch( std::exception &e )
    {
@@ -1482,7 +1480,7 @@ void TGMSStatusStream::StatusJacobianError( int num1, int num2, const std::strin
    }
 }
 
-std::function<void( const std::string & )> TGMSStatusStream::commonStatusFunc( const std::string &s1, const std::string &s2 )
+std::function<void( const std::string & )> TGMSStatusStream::commonStatusFunc( const std::string &s1, const std::string &s2 ) const
 {
    return [&]( const std::string &s3 ) {
       try
@@ -1496,7 +1494,7 @@ std::function<void( const std::string & )> TGMSStatusStream::commonStatusFunc( c
    };
 }
 
-bool opentextmsg( FILE *&f, const std::string &fn, gdlib::gmsgen::tfileaction fa, std::string &msg )
+bool opentextmsg( FILE *&f, const std::string &fn, const tfileaction fa, std::string &msg )
 {
    const char *mode {};
    // shouldn't these be binary mode on Windows to avoid weird \r\n behavior?
@@ -1515,14 +1513,14 @@ bool opentextmsg( FILE *&f, const std::string &fn, gdlib::gmsgen::tfileaction fa
          throw std::runtime_error( "Unknown file action provided!"s );
    }
    f = fopen( fn.c_str(), mode );
-   int ioRes { f ? 0 : errno };
+   const int ioRes { f ? 0 : errno };
    msg = !ioRes ? ""s : SysErrorMessage( ioRes );
    return !ioRes;
 }
 
 static void initialization()
 {
-   bool isntUnix = rtl::p3platform::OSFileType() != rtl::p3platform::tOSFileType::OSFileUNIX;
+   const bool isntUnix = rtl::p3platform::OSFileType() != rtl::p3platform::tOSFileType::OSFileUNIX;
    termString = isntUnix ? "\r\n"s : "\n"s;
 }
 
diff --git a/src/gdlib/statlibobj.h b/src/gdlib/statlibobj.h
index 7c2d7f8..214f570 100644
--- a/src/gdlib/statlibobj.h
+++ b/src/gdlib/statlibobj.h
@@ -76,10 +76,10 @@ class TGMSLogStream
    void CndShowStatLine();
    void ShowStatLine();
    void gstatStartWriting();
-   void writeln_gf( const std::string &msg );
-   void write_gf( const std::string &msg );
-   void writeln_gf( const char *msg );
-   void write_gf( const char *msg );
+   void writeln_gf( const std::string &msg ) const;
+   void write_gf( const std::string &msg ) const;
+   void writeln_gf( const char *msg ) const;
+   void write_gf( const char *msg ) const;
 
 public:
    explicit TGMSLogStream( std::string &Msg );
@@ -102,7 +102,7 @@ class TGMSLogStream
    void LogDumpFilename( const std::string &prfx, bool enabled, const std::string &what, const std::string &gs, gdlib::gmsgen::tfileaction fa, int ioResOrNeg );
    void LogWriteLn( const std::string &s );
    void LogWrite( const std::string &p );
-   void LogWritePlain( const std::string &s );
+   void LogWritePlain( const std::string &s ) const;
    void showCounts();
 
    // Properties
@@ -116,7 +116,7 @@ class TGMSLogStream
 
    [[nodiscard]] std::string getRedirFilename() const;
    [[nodiscard]] std::string getRedirString() const;
-   std::string getShortRedirString( const std::string &Dir );
+   std::string getShortRedirString( const std::string &Dir ) const;
 
    void SetOSMemory( int v );
 
@@ -143,10 +143,10 @@ struct rcerrrec {
 };
 using trcerrrec = rcerrrec *;
 
-class TGMSStatusStream
+class TGMSStatusStream final
 {
    void *Fgfusrmem {};
-   gdlib::stattypes::tgwrite *Fgfcb {};
+   stattypes::tgwrite *Fgfcb {};
    FILE *Ffsysout {}, *Ffstat {};
    std::string Ffnstat;
    bool Fcopysysout {};
@@ -161,26 +161,26 @@ class TGMSStatusStream
    trcerrrec Fnextheader {};
    trcerrtyp Fnexterror {};
 
-   void writeln_gf( const std::string &msg );
-   void write_gf( const std::string &msg );
+   void writeln_gf( const std::string &msg ) const;
+   void write_gf( const std::string &msg ) const;
    void SolverErrorInit();
    trcerrtxt SolverErrorMessage( const std::string &s );
    void SolverErrorAdd( int rownum, int columnnum, const std::string &msg );
    bool checkfile( std::string &msg );
 
-   std::function<void( const std::string & )> commonStatusFunc( const std::string &s1, const std::string &s2 );
+   [[nodiscard]] std::function<void( const std::string & )> commonStatusFunc( const std::string &s1, const std::string &s2 ) const;
 
 public:
    explicit TGMSStatusStream( std::string &Msg );
-   virtual ~TGMSStatusStream();
+   ~TGMSStatusStream();
 
-   void registerWriteCallback( gdlib::stattypes::tgwrite *fptr, void *usermem );
+   void registerWriteCallback( stattypes::tgwrite *fptr, void *usermem );
    void StatusErrorFree();
    void StatusDumpFirst();
-   bool StatusAppend( const std::string &fn, std::string &msg );
+   bool StatusAppend( const std::string &fn, std::string &msg ) const;
    void StatusProcessFirst();
    bool StatusDumpNext( std::string &msg );
-   bool StatusProcessNext( gdlib::stattypes::tstatusproc &statusproc, std::string &msg1, std::string &msg2, int &num );
+   bool StatusProcessNext( stattypes::tstatusproc &statusproc, std::string &msg1, std::string &msg2, int &num );
    void StatusSetFilename( const std::string &fn );
    bool StatusDummy( std::string &msg );
    void StatusErrorFirst();
@@ -191,27 +191,27 @@ class TGMSStatusStream
    bool StatusErrorDetail( int &cnt, std::string &msg );
    void StatusSetRowCol( int rowmax, int colmax );
    void StatusClose();
-   bool StatusFileOpen( gdlib::gmsgen::tfileaction AAction, std::string &msg );
-   void StatusWriteLn( const std::string &s );
-   void StatusWrite( const std::string &p );
-   void StatusWritePlain( const std::string &s );
-   void StatusTerminationRequestfromSolver();
-   void StatusCopyOn();
-   void StatusCopyOff();
-   void StatusLSTAnchor( const std::string &s );
-   void StatusCopyLine( const std::string &s );
-   void StatusCopyFile( const std::string &s );
-   void StatusCopyFileOnSysOut( const std::string &s );
-   void StatusEndOfFile();
-   void StatusSysOut();
-   void StatusPageEject();
+   bool StatusFileOpen( gmsgen::tfileaction AAction, std::string &msg );
+   void StatusWriteLn( const std::string &s ) const;
+   void StatusWrite( const std::string &p ) const;
+   void StatusWritePlain( const std::string &s ) const;
+   void StatusTerminationRequestfromSolver() const;
+   void StatusCopyOn() const;
+   void StatusCopyOff() const;
+   void StatusLSTAnchor( const std::string &s ) const;
+   void StatusCopyLine( const std::string &s ) const;
+   void StatusCopyFile( const std::string &s ) const;
+   void StatusCopyFileOnSysOut( const std::string &s ) const;
+   void StatusEndOfFile() const;
+   void StatusSysOut() const;
+   void StatusPageEject() const;
    void StatusSetEditSymbol( char c );
-   void StatusAuditLine( const std::string &s );
-   void StatusEquationName( const std::string &s1, int num, std::string &s2 );
-   void StatusVariableName( const std::string &s1, int num, const std::string &s2 );
-   void StatusEquationError( int num, const std::string &s );
-   void StatusVariableError( int num, const std::string &s );
-   void StatusJacobianError( int num1, int num2, const std::string &s );
+   void StatusAuditLine( const std::string &s ) const;
+   void StatusEquationName( const std::string &s1, int num, const std::string &s2 ) const;
+   void StatusVariableName( const std::string &s1, int num, const std::string &s2 ) const;
+   void StatusEquationError( int num, const std::string &s ) const;
+   void StatusVariableError( int num, const std::string &s ) const;
+   void StatusJacobianError( int num1, int num2, const std::string &s ) const;
 };
 
 
diff --git a/src/rtl/p3utils.cpp b/src/rtl/p3utils.cpp
index d9b4324..36489c2 100644
--- a/src/rtl/p3utils.cpp
+++ b/src/rtl/p3utils.cpp
@@ -75,7 +75,6 @@
    #endif
    #include <netinet/in.h>
    #include <unistd.h>
-   #include <dlfcn.h>
    #include <poll.h>
 #endif
 
@@ -322,7 +321,7 @@ static constexpr std::array<DWORD, 3> accessMode {
 // this works for GDX so we do it: it is kind of silly to use the
 // shareMode var then but why not?
 static constexpr std::array<DWORD, 3> shareMode {
-        FILE_SHARE_READ | FILE_SHARE_WRITE,
+        FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
         FILE_SHARE_READ | FILE_SHARE_WRITE,
         FILE_SHARE_READ | FILE_SHARE_WRITE };
 static constexpr std::array<DWORD, 3> createHow {
@@ -1161,122 +1160,6 @@ int p3GetExecName( std::string &execName, std::string &msg )
 #endif
 }
 
-// FIXME: Do not always return false!
-static bool isLibrary()
-{
-   return false;
-}
-
-static int xGetLibName( std::string &libName, std::string &msg )
-{
-   char libBuf[4096];
-   msg.clear();
-   int rc;
-
-#if defined( __linux ) || defined( __APPLE__ )
-   {
-      char tmpBuf[2048];
-      static_assert( sizeof( tmpBuf ) == 2048 );
-      Dl_info dlInfo;
-      const int k = dladdr( reinterpret_cast<void *>( &xGetLibName ), &dlInfo );
-      if( k > 0 )
-      {
-         strncpy( tmpBuf, dlInfo.dli_fname, sizeof( tmpBuf ) - 1 );
-         tmpBuf[sizeof( tmpBuf ) - 1] = '\0';
-         if( realpath( tmpBuf, libBuf ) )
-            rc = 0;
-         else
-         {
-            myStrError( errno, tmpBuf, sizeof( tmpBuf ) );
-            msg = "realpath() failure: "s + tmpBuf;
-            *libBuf = '\0';
-            rc = 5;
-         }
-      }
-      else
-      {
-         msg = "dladdr() failure"s;
-         *libBuf = '\0';
-         rc = 4;
-      }
-   }
-#elif defined( _WIN32 )
-   {
-      HMODULE h;
-      int k = GetModuleHandleEx( GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
-                                     GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
-                             reinterpret_cast<LPCTSTR>( &xGetLibName ), &h );
-      if( k )
-      { /* OK: got a handle */
-         k = static_cast<int>( GetModuleFileNameA( h, libBuf, sizeof( libBuf ) ) );
-         if( 0 == k )
-         {
-            msg = "GetModuleFileName() failure: rc="s + rtl::sysutils_p3::IntToStr(k);
-            *libBuf = '\0';
-            rc = 5;
-         }
-         else
-            rc = 0;
-      }
-      else
-      {
-         msg = "GetModuleHandleEx() failure: rc="s + rtl::sysutils_p3::IntToStr(k);
-         *libBuf = '\0';
-         rc = 4;
-      }
-   }
-#else
-   *libBuf = '\0';
-   msg = "not implemented for this platform"s;
-   rc = 8;
-#endif
-   libName.assign( libBuf );
-   return 0 == rc && strlen( libBuf ) > 255 ? 1 : rc;
-} /* xGetLibName */
-
-int p3GetLibName( std::string &libName, std::string &msg )
-{
-   return xGetLibName( libName, msg );
-#if defined( _WIN32 )
-   libName.clear();
-   if( !isLibrary() )
-   {
-      msg = "Not called from a library"s;
-      return 2;
-   }
-   std::array<char, 256> buf;
-   HMODULE hinstance;
-   auto rc { GetModuleFileNameA( hinstance, buf.data(), static_cast<DWORD>(buf.size()) ) };
-   if( !rc )
-   {
-      msg = "GetModuleFileNameA call failed"s;
-      return 3;
-   }
-   else if( rc >= 256 )
-   {
-      libName.assign( buf.data() );
-      msg = "Result truncated to 255 characters"s;
-      return 1;
-   }
-   else
-   {
-      libName.assign( buf.data() );
-      msg.clear();
-      return 0;
-   }
-#else
-   if( !isLibrary() )
-   {
-      libName.clear();
-      msg = "Not called from a library"s;
-      return 2;
-   }
-   libName.clear();
-   msg = "P3: not yet implemented"s;
-   return 9;
-#endif
-}
-
 #ifdef __IN_CPPMEX__
 bool p3GetFirstMACAddress( std::string &mac )
 {
diff --git a/src/rtl/p3utils.h b/src/rtl/p3utils.h
index 668337c..f41ae00 100644
--- a/src/rtl/p3utils.h
+++ b/src/rtl/p3utils.h
@@ -86,7 +86,6 @@ bool P3SetEnvPC( const std::string &name, char *val );
 uint32_t P3GetEnvPC( const std::string &name, char *buf, uint32_t bufSize );
 
 int p3GetExecName( std::string &execName, std::string &msg );
-int p3GetLibName( std::string &libName, std::string &msg );
 
 bool p3GetMemoryInfo( uint64_t &rss, uint64_t &vss );
 
diff --git a/src/tests/gdxtests.cpp b/src/tests/gdxtests.cpp
index 70476b1..892108e 100644
--- a/src/tests/gdxtests.cpp
+++ b/src/tests/gdxtests.cpp
@@ -1891,6 +1891,25 @@ TEST_CASE( "Test simple write/read with compression activated" )
    std::filesystem::remove( fn );
 }
 
+TEST_CASE( "Test opening a file for reading and then deleting (while it is open)")
+{
+   const auto fn {"unlocked.gdx"s};
+   testWrite(fn, [&](TGXFileObj &pgx) {
+      pgx.gdxDataWriteRawStart( "i", "", 1, dt_set, 0 );
+      pgx.gdxDataWriteDone();
+   });
+   testRead( fn, [&](TGXFileObj &pgx) {
+      std::filesystem::remove(fn); // this is mean. :)
+      int nrRecs;
+      // should fail now!
+      REQUIRE(pgx.gdxDataReadRawStart( 1, nrRecs ));
+      int key, dimFrst;
+      double val;
+      REQUIRE_FALSE(pgx.gdxDataReadRaw( &key, &val, dimFrst ));
+      REQUIRE_FALSE(std::filesystem::exists( fn ));
+   } );
+}
+
 TEST_CASE( "Test symbol index max UEL length" )
 {
    testReadModelGDX( "trnsport"s, [&]( TGXFileObj &pgx ) {