SL-315 WIP - added a call stack extractor for windows to help with tracing joint issues (of course, could be used for other things as well).

7 files changed, 1751 insertions, 0 deletions

diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 5863310162..635344bc4b 100755
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -38,6 +38,7 @@ set(llcommon_SOURCE_FILES
     llbase64.cpp
     llbitpack.cpp
     llcallbacklist.cpp
+    llcallstack.cpp
     llcommon.cpp
     llcommonutils.cpp
     llcoros.cpp
@@ -111,6 +112,7 @@ set(llcommon_SOURCE_FILES
     llworkerthread.cpp
     timing.cpp
     u64.cpp
+    StackWalker.cpp
     )
     
 set(llcommon_HEADER_FILES
@@ -131,6 +133,7 @@ set(llcommon_HEADER_FILES
     llbitpack.h
     llboost.h
     llcallbacklist.h
+    llcallstack.h
     llcommon.h
     llcommonutils.h
     llcoros.h
@@ -231,6 +234,7 @@ set(llcommon_HEADER_FILES
     stringize.h
     timer.h
     u64.h
+    StackWalker.h
     )
 
 set_source_files_properties(${llcommon_HEADER_FILES}
diff --git a/indra/llcommon/StackWalker.cpp b/indra/llcommon/StackWalker.cpp
new file mode 100644
index 0000000000..da52386a22
--- /dev/null
+++ b/indra/llcommon/StackWalker.cpp
@@ -0,0 +1,1385 @@
+/**********************************************************************
+ * 
+ * StackWalker.cpp
+ * http://stackwalker.codeplex.com/
+ *
+ *
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ *
+ * History:
+ *  2005-07-27   v1    - First public release on http://www.codeproject.com/
+ *                       http://www.codeproject.com/threads/StackWalker.asp
+ *  2005-07-28   v2    - Changed the params of the constructor and ShowCallstack
+ *                       (to simplify the usage)
+ *  2005-08-01   v3    - Changed to use 'CONTEXT_FULL' instead of CONTEXT_ALL 
+ *                       (should also be enough)
+ *                     - Changed to compile correctly with the PSDK of VC7.0
+ *                       (GetFileVersionInfoSizeA and GetFileVersionInfoA is wrongly defined:
+ *                        it uses LPSTR instead of LPCSTR as first paremeter)
+ *                     - Added declarations to support VC5/6 without using 'dbghelp.h'
+ *                     - Added a 'pUserData' member to the ShowCallstack function and the 
+ *                       PReadProcessMemoryRoutine declaration (to pass some user-defined data, 
+ *                       which can be used in the readMemoryFunction-callback)
+ *  2005-08-02   v4    - OnSymInit now also outputs the OS-Version by default
+ *                     - Added example for doing an exception-callstack-walking in main.cpp
+ *                       (thanks to owillebo: http://www.codeproject.com/script/profile/whos_who.asp?id=536268)
+ *  2005-08-05   v5    - Removed most Lint (http://www.gimpel.com/) errors... thanks to Okko Willeboordse!
+ *  2008-08-04   v6    - Fixed Bug: Missing LEAK-end-tag
+ *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=2502890#xx2502890xx
+ *                       Fixed Bug: Compiled with "WIN32_LEAN_AND_MEAN"
+ *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=1824718#xx1824718xx
+ *                       Fixed Bug: Compiling with "/Wall"
+ *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=2638243#xx2638243xx
+ *                       Fixed Bug: Now checking SymUseSymSrv
+ *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=1388979#xx1388979xx
+ *                       Fixed Bug: Support for recursive function calls
+ *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=1434538#xx1434538xx
+ *                       Fixed Bug: Missing FreeLibrary call in "GetModuleListTH32"
+ *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=1326923#xx1326923xx
+ *                       Fixed Bug: SymDia is number 7, not 9!
+ *  2008-09-11   v7      For some (undocumented) reason, dbhelp.h is needing a packing of 8!
+ *                       Thanks to Teajay which reported the bug...
+ *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=2718933#xx2718933xx
+ *  2008-11-27   v8      Debugging Tools for Windows are now stored in a different directory
+ *                       Thanks to Luiz Salamon which reported this "bug"...
+ *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=2822736#xx2822736xx
+ *  2009-04-10   v9      License slihtly corrected (<ORGANIZATION> replaced)
+ *  2009-11-01   v10     Moved to http://stackwalker.codeplex.com/
+ *  2009-11-02   v11     Now try to use IMAGEHLP_MODULE64_V3 if available
+ *  2010-04-15   v12     Added support for VS2010 RTM
+ *  2010-05-25   v13     Now using secure MyStrcCpy. Thanks to luke.simon:
+ *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=3477467#xx3477467xx
+ *  2013-01-07   v14     Runtime Check Error VS2010 Debug Builds fixed:
+ *                       http://stackwalker.codeplex.com/workitem/10511
+ *
+ *
+ * LICENSE (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ *   Copyright (c) 2005-2013, Jochen Kalmbach
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without modification, 
+ *   are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, 
+ *   this list of conditions and the following disclaimer. 
+ *   Redistributions in binary form must reproduce the above copyright notice, 
+ *   this list of conditions and the following disclaimer in the documentation 
+ *   and/or other materials provided with the distribution. 
+ *   Neither the name of Jochen Kalmbach nor the names of its contributors may be 
+ *   used to endorse or promote products derived from this software without 
+ *   specific prior written permission. 
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+ *   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
+ *   THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ *   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 
+ *   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
+ *   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+ *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 
+ *   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
+ *   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ **********************************************************************/
+#if LL_WINDOWS
+
+#include <windows.h>
+#include <tchar.h>
+#include <stdio.h>
+#include <stdlib.h>
+#pragma comment(lib, "version.lib")  // for "VerQueryValue"
+#pragma warning(disable:4826)
+
+#include "StackWalker.h"
+
+
+// If VC7 and later, then use the shipped 'dbghelp.h'-file
+#pragma pack(push,8)
+#if _MSC_VER >= 1300
+#include <dbghelp.h>
+#else
+// inline the important dbghelp.h-declarations...
+typedef enum {
+    SymNone = 0,
+    SymCoff,
+    SymCv,
+    SymPdb,
+    SymExport,
+    SymDeferred,
+    SymSym,
+    SymDia,
+    SymVirtual,
+    NumSymTypes
+} SYM_TYPE;
+typedef struct _IMAGEHLP_LINE64 {
+    DWORD                       SizeOfStruct;           // set to sizeof(IMAGEHLP_LINE64)
+    PVOID                       Key;                    // internal
+    DWORD                       LineNumber;             // line number in file
+    PCHAR                       FileName;               // full filename
+    DWORD64                     Address;                // first instruction of line
+} IMAGEHLP_LINE64, *PIMAGEHLP_LINE64;
+typedef struct _IMAGEHLP_MODULE64 {
+    DWORD                       SizeOfStruct;           // set to sizeof(IMAGEHLP_MODULE64)
+    DWORD64                     BaseOfImage;            // base load address of module
+    DWORD                       ImageSize;              // virtual size of the loaded module
+    DWORD                       TimeDateStamp;          // date/time stamp from pe header
+    DWORD                       CheckSum;               // checksum from the pe header
+    DWORD                       NumSyms;                // number of symbols in the symbol table
+    SYM_TYPE                    SymType;                // type of symbols loaded
+    CHAR                        ModuleName[32];         // module name
+    CHAR                        ImageName[256];         // image name
+    CHAR                        LoadedImageName[256];   // symbol file name
+} IMAGEHLP_MODULE64, *PIMAGEHLP_MODULE64;
+typedef struct _IMAGEHLP_SYMBOL64 {
+    DWORD                       SizeOfStruct;           // set to sizeof(IMAGEHLP_SYMBOL64)
+    DWORD64                     Address;                // virtual address including dll base address
+    DWORD                       Size;                   // estimated size of symbol, can be zero
+    DWORD                       Flags;                  // info about the symbols, see the SYMF defines
+    DWORD                       MaxNameLength;          // maximum size of symbol name in 'Name'
+    CHAR                        Name[1];                // symbol name (null terminated string)
+} IMAGEHLP_SYMBOL64, *PIMAGEHLP_SYMBOL64;
+typedef enum {
+    AddrMode1616,
+    AddrMode1632,
+    AddrModeReal,
+    AddrModeFlat
+} ADDRESS_MODE;
+typedef struct _tagADDRESS64 {
+    DWORD64       Offset;
+    WORD          Segment;
+    ADDRESS_MODE  Mode;
+} ADDRESS64, *LPADDRESS64;
+typedef struct _KDHELP64 {
+    DWORD64   Thread;
+    DWORD   ThCallbackStack;
+    DWORD   ThCallbackBStore;
+    DWORD   NextCallback;
+    DWORD   FramePointer;
+    DWORD64   KiCallUserMode;
+    DWORD64   KeUserCallbackDispatcher;
+    DWORD64   SystemRangeStart;
+    DWORD64  Reserved[8];
+} KDHELP64, *PKDHELP64;
+typedef struct _tagSTACKFRAME64 {
+    ADDRESS64   AddrPC;               // program counter
+    ADDRESS64   AddrReturn;           // return address
+    ADDRESS64   AddrFrame;            // frame pointer
+    ADDRESS64   AddrStack;            // stack pointer
+    ADDRESS64   AddrBStore;           // backing store pointer
+    PVOID       FuncTableEntry;       // pointer to pdata/fpo or NULL
+    DWORD64     Params[4];            // possible arguments to the function
+    BOOL        Far;                  // WOW far call
+    BOOL        Virtual;              // is this a virtual frame?
+    DWORD64     Reserved[3];
+    KDHELP64    KdHelp;
+} STACKFRAME64, *LPSTACKFRAME64;
+typedef
+BOOL
+(__stdcall *PREAD_PROCESS_MEMORY_ROUTINE64)(
+    HANDLE      hProcess,
+    DWORD64     qwBaseAddress,
+    PVOID       lpBuffer,
+    DWORD       nSize,
+    LPDWORD     lpNumberOfBytesRead
+    );
+typedef
+PVOID
+(__stdcall *PFUNCTION_TABLE_ACCESS_ROUTINE64)(
+    HANDLE  hProcess,
+    DWORD64 AddrBase
+    );
+typedef
+DWORD64
+(__stdcall *PGET_MODULE_BASE_ROUTINE64)(
+    HANDLE  hProcess,
+    DWORD64 Address
+    );
+typedef
+DWORD64
+(__stdcall *PTRANSLATE_ADDRESS_ROUTINE64)(
+    HANDLE    hProcess,
+    HANDLE    hThread,
+    LPADDRESS64 lpaddr
+    );
+#define SYMOPT_CASE_INSENSITIVE         0x00000001
+#define SYMOPT_UNDNAME                  0x00000002
+#define SYMOPT_DEFERRED_LOADS           0x00000004
+#define SYMOPT_NO_CPP                   0x00000008
+#define SYMOPT_LOAD_LINES               0x00000010
+#define SYMOPT_OMAP_FIND_NEAREST        0x00000020
+#define SYMOPT_LOAD_ANYTHING            0x00000040
+#define SYMOPT_IGNORE_CVREC             0x00000080
+#define SYMOPT_NO_UNQUALIFIED_LOADS     0x00000100
+#define SYMOPT_FAIL_CRITICAL_ERRORS     0x00000200
+#define SYMOPT_EXACT_SYMBOLS            0x00000400
+#define SYMOPT_ALLOW_ABSOLUTE_SYMBOLS   0x00000800
+#define SYMOPT_IGNORE_NT_SYMPATH        0x00001000
+#define SYMOPT_INCLUDE_32BIT_MODULES    0x00002000
+#define SYMOPT_PUBLICS_ONLY             0x00004000
+#define SYMOPT_NO_PUBLICS               0x00008000
+#define SYMOPT_AUTO_PUBLICS             0x00010000
+#define SYMOPT_NO_IMAGE_SEARCH          0x00020000
+#define SYMOPT_SECURE                   0x00040000
+#define SYMOPT_DEBUG                    0x80000000
+#define UNDNAME_COMPLETE                 (0x0000)  // Enable full undecoration
+#define UNDNAME_NAME_ONLY                (0x1000)  // Crack only the name for primary declaration;
+#endif  // _MSC_VER < 1300
+#pragma pack(pop)
+
+// Some missing defines (for VC5/6):
+#ifndef INVALID_FILE_ATTRIBUTES
+#define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
+#endif  
+
+
+// secure-CRT_functions are only available starting with VC8
+#if _MSC_VER < 1400
+#define strcpy_s(dst, len, src) strcpy(dst, src)
+#define strncpy_s(dst, len, src, maxLen) strncpy(dst, len, src)
+#define strcat_s(dst, len, src) strcat(dst, src)
+#define _snprintf_s _snprintf
+#define _tcscat_s _tcscat
+#endif
+
+static void MyStrCpy(char* szDest, size_t nMaxDestSize, const char* szSrc)
+{
+  if (nMaxDestSize <= 0) return;
+  strncpy_s(szDest, nMaxDestSize, szSrc, _TRUNCATE);
+  szDest[nMaxDestSize-1] = 0;  // INFO: _TRUNCATE will ensure that it is nul-terminated; but with older compilers (<1400) it uses "strncpy" and this does not!)
+}  // MyStrCpy
+
+// Normally it should be enough to use 'CONTEXT_FULL' (better would be 'CONTEXT_ALL')
+#define USED_CONTEXT_FLAGS CONTEXT_FULL
+
+
+class StackWalkerInternal
+{
+public:
+  StackWalkerInternal(StackWalker *parent, HANDLE hProcess)
+  {
+    m_parent = parent;
+    m_hDbhHelp = NULL;
+    pSC = NULL;
+    m_hProcess = hProcess;
+    m_szSymPath = NULL;
+    pSFTA = NULL;
+    pSGLFA = NULL;
+    pSGMB = NULL;
+    pSGMI = NULL;
+    pSGO = NULL;
+    pSGSFA = NULL;
+    pSI = NULL;
+    pSLM = NULL;
+    pSSO = NULL;
+    pSW = NULL;
+    pUDSN = NULL;
+    pSGSP = NULL;
+  }
+  ~StackWalkerInternal()
+  {
+    if (pSC != NULL)
+      pSC(m_hProcess);  // SymCleanup
+    if (m_hDbhHelp != NULL)
+      FreeLibrary(m_hDbhHelp);
+    m_hDbhHelp = NULL;
+    m_parent = NULL;
+    if(m_szSymPath != NULL)
+      free(m_szSymPath);
+    m_szSymPath = NULL;
+  }
+  BOOL Init(LPCSTR szSymPath)
+  {
+    if (m_parent == NULL)
+      return FALSE;
+    // Dynamically load the Entry-Points for dbghelp.dll:
+    // First try to load the newsest one from
+    TCHAR szTemp[4096];
+    // But before wqe do this, we first check if the ".local" file exists
+    if (GetModuleFileName(NULL, szTemp, 4096) > 0)
+    {
+      _tcscat_s(szTemp, _T(".local"));
+      if (GetFileAttributes(szTemp) == INVALID_FILE_ATTRIBUTES)
+      {
+        // ".local" file does not exist, so we can try to load the dbghelp.dll from the "Debugging Tools for Windows"
+        // Ok, first try the new path according to the archtitecture:
+#ifdef _M_IX86
+        if ( (m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0) )
+        {
+          _tcscat_s(szTemp, _T("\\Debugging Tools for Windows (x86)\\dbghelp.dll"));
+          // now check if the file exists:
+          if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
+          {
+            m_hDbhHelp = LoadLibrary(szTemp);
+          }
+        }
+#elif _M_X64
+        if ( (m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0) )
+        {
+          _tcscat_s(szTemp, _T("\\Debugging Tools for Windows (x64)\\dbghelp.dll"));
+          // now check if the file exists:
+          if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
+          {
+            m_hDbhHelp = LoadLibrary(szTemp);
+          }
+        }
+#elif _M_IA64
+        if ( (m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0) )
+        {
+          _tcscat_s(szTemp, _T("\\Debugging Tools for Windows (ia64)\\dbghelp.dll"));
+          // now check if the file exists:
+          if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
+          {
+            m_hDbhHelp = LoadLibrary(szTemp);
+          }
+        }
+#endif
+        // If still not found, try the old directories...
+        if ( (m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0) )
+        {
+          _tcscat_s(szTemp, _T("\\Debugging Tools for Windows\\dbghelp.dll"));
+          // now check if the file exists:
+          if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
+          {
+            m_hDbhHelp = LoadLibrary(szTemp);
+          }
+        }
+#if defined _M_X64 || defined _M_IA64
+        // Still not found? Then try to load the (old) 64-Bit version:
+        if ( (m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0) )
+        {
+          _tcscat_s(szTemp, _T("\\Debugging Tools for Windows 64-Bit\\dbghelp.dll"));
+          if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
+          {
+            m_hDbhHelp = LoadLibrary(szTemp);
+          }
+        }
+#endif
+      }
+    }
+    if (m_hDbhHelp == NULL)  // if not already loaded, try to load a default-one
+      m_hDbhHelp = LoadLibrary( _T("dbghelp.dll") );
+    if (m_hDbhHelp == NULL)
+      return FALSE;
+    pSI = (tSI) GetProcAddress(m_hDbhHelp, "SymInitialize" );
+    pSC = (tSC) GetProcAddress(m_hDbhHelp, "SymCleanup" );
+
+    pSW = (tSW) GetProcAddress(m_hDbhHelp, "StackWalk64" );
+    pSGO = (tSGO) GetProcAddress(m_hDbhHelp, "SymGetOptions" );
+    pSSO = (tSSO) GetProcAddress(m_hDbhHelp, "SymSetOptions" );
+
+    pSFTA = (tSFTA) GetProcAddress(m_hDbhHelp, "SymFunctionTableAccess64" );
+    pSGLFA = (tSGLFA) GetProcAddress(m_hDbhHelp, "SymGetLineFromAddr64" );
+    pSGMB = (tSGMB) GetProcAddress(m_hDbhHelp, "SymGetModuleBase64" );
+    pSGMI = (tSGMI) GetProcAddress(m_hDbhHelp, "SymGetModuleInfo64" );
+    pSGSFA = (tSGSFA) GetProcAddress(m_hDbhHelp, "SymGetSymFromAddr64" );
+    pUDSN = (tUDSN) GetProcAddress(m_hDbhHelp, "UnDecorateSymbolName" );
+    pSLM = (tSLM) GetProcAddress(m_hDbhHelp, "SymLoadModule64" );
+    pSGSP =(tSGSP) GetProcAddress(m_hDbhHelp, "SymGetSearchPath" );
+
+    if ( pSC == NULL || pSFTA == NULL || pSGMB == NULL || pSGMI == NULL ||
+      pSGO == NULL || pSGSFA == NULL || pSI == NULL || pSSO == NULL ||
+      pSW == NULL || pUDSN == NULL || pSLM == NULL )
+    {
+      FreeLibrary(m_hDbhHelp);
+      m_hDbhHelp = NULL;
+      pSC = NULL;
+      return FALSE;
+    }
+
+    // SymInitialize
+    if (szSymPath != NULL)
+      m_szSymPath = _strdup(szSymPath);
+    if (this->pSI(m_hProcess, m_szSymPath, FALSE) == FALSE)
+      this->m_parent->OnDbgHelpErr("SymInitialize", GetLastError(), 0);
+      
+    DWORD symOptions = this->pSGO();  // SymGetOptions
+    symOptions |= SYMOPT_LOAD_LINES;
+    symOptions |= SYMOPT_FAIL_CRITICAL_ERRORS;
+    //symOptions |= SYMOPT_NO_PROMPTS;
+    // SymSetOptions
+    symOptions = this->pSSO(symOptions);
+
+    char buf[StackWalker::STACKWALK_MAX_NAMELEN] = {0};
+    if (this->pSGSP != NULL)
+    {
+      if (this->pSGSP(m_hProcess, buf, StackWalker::STACKWALK_MAX_NAMELEN) == FALSE)
+        this->m_parent->OnDbgHelpErr("SymGetSearchPath", GetLastError(), 0);
+    }
+    char szUserName[1024] = {0};
+    DWORD dwSize = 1024;
+    GetUserNameA(szUserName, &dwSize);
+    this->m_parent->OnSymInit(buf, symOptions, szUserName);
+
+    return TRUE;
+  }
+
+  StackWalker *m_parent;
+
+  HMODULE m_hDbhHelp;
+  HANDLE m_hProcess;
+  LPSTR m_szSymPath;
+
+#pragma pack(push,8)
+typedef struct IMAGEHLP_MODULE64_V3 {
+    DWORD    SizeOfStruct;           // set to sizeof(IMAGEHLP_MODULE64)
+    DWORD64  BaseOfImage;            // base load address of module
+    DWORD    ImageSize;              // virtual size of the loaded module
+    DWORD    TimeDateStamp;          // date/time stamp from pe header
+    DWORD    CheckSum;               // checksum from the pe header
+    DWORD    NumSyms;                // number of symbols in the symbol table
+    SYM_TYPE SymType;                // type of symbols loaded
+    CHAR     ModuleName[32];         // module name
+    CHAR     ImageName[256];         // image name
+    CHAR     LoadedImageName[256];   // symbol file name
+    // new elements: 07-Jun-2002
+    CHAR     LoadedPdbName[256];     // pdb file name
+    DWORD    CVSig;                  // Signature of the CV record in the debug directories
+    CHAR     CVData[MAX_PATH * 3];   // Contents of the CV record
+    DWORD    PdbSig;                 // Signature of PDB
+    GUID     PdbSig70;               // Signature of PDB (VC 7 and up)
+    DWORD    PdbAge;                 // DBI age of pdb
+    BOOL     PdbUnmatched;           // loaded an unmatched pdb
+    BOOL     DbgUnmatched;           // loaded an unmatched dbg
+    BOOL     LineNumbers;            // we have line number information
+    BOOL     GlobalSymbols;          // we have internal symbol information
+    BOOL     TypeInfo;               // we have type information
+    // new elements: 17-Dec-2003
+    BOOL     SourceIndexed;          // pdb supports source server
+    BOOL     Publics;                // contains public symbols
+};
+
+typedef struct IMAGEHLP_MODULE64_V2 {
+    DWORD    SizeOfStruct;           // set to sizeof(IMAGEHLP_MODULE64)
+    DWORD64  BaseOfImage;            // base load address of module
+    DWORD    ImageSize;              // virtual size of the loaded module
+    DWORD    TimeDateStamp;          // date/time stamp from pe header
+    DWORD    CheckSum;               // checksum from the pe header
+    DWORD    NumSyms;                // number of symbols in the symbol table
+    SYM_TYPE SymType;                // type of symbols loaded
+    CHAR     ModuleName[32];         // module name
+    CHAR     ImageName[256];         // image name
+    CHAR     LoadedImageName[256];   // symbol file name
+};
+#pragma pack(pop)
+
+
+  // SymCleanup()
+  typedef BOOL (__stdcall *tSC)( IN HANDLE hProcess );
+  tSC pSC;
+
+  // SymFunctionTableAccess64()
+  typedef PVOID (__stdcall *tSFTA)( HANDLE hProcess, DWORD64 AddrBase );
+  tSFTA pSFTA;
+
+  // SymGetLineFromAddr64()
+  typedef BOOL (__stdcall *tSGLFA)( IN HANDLE hProcess, IN DWORD64 dwAddr,
+    OUT PDWORD pdwDisplacement, OUT PIMAGEHLP_LINE64 Line );
+  tSGLFA pSGLFA;
+
+  // SymGetModuleBase64()
+  typedef DWORD64 (__stdcall *tSGMB)( IN HANDLE hProcess, IN DWORD64 dwAddr );
+  tSGMB pSGMB;
+
+  // SymGetModuleInfo64()
+  typedef BOOL (__stdcall *tSGMI)( IN HANDLE hProcess, IN DWORD64 dwAddr, OUT IMAGEHLP_MODULE64_V3 *ModuleInfo );
+  tSGMI pSGMI;
+
+  // SymGetOptions()
+  typedef DWORD (__stdcall *tSGO)( VOID );
+  tSGO pSGO;
+
+  // SymGetSymFromAddr64()
+  typedef BOOL (__stdcall *tSGSFA)( IN HANDLE hProcess, IN DWORD64 dwAddr,
+    OUT PDWORD64 pdwDisplacement, OUT PIMAGEHLP_SYMBOL64 Symbol );
+  tSGSFA pSGSFA;
+
+  // SymInitialize()
+  typedef BOOL (__stdcall *tSI)( IN HANDLE hProcess, IN PSTR UserSearchPath, IN BOOL fInvadeProcess );
+  tSI pSI;
+
+  // SymLoadModule64()
+  typedef DWORD64 (__stdcall *tSLM)( IN HANDLE hProcess, IN HANDLE hFile,
+    IN PSTR ImageName, IN PSTR ModuleName, IN DWORD64 BaseOfDll, IN DWORD SizeOfDll );
+  tSLM pSLM;
+
+  // SymSetOptions()
+  typedef DWORD (__stdcall *tSSO)( IN DWORD SymOptions );
+  tSSO pSSO;
+
+  // StackWalk64()
+  typedef BOOL (__stdcall *tSW)( 
+    DWORD MachineType, 
+    HANDLE hProcess,
+    HANDLE hThread, 
+    LPSTACKFRAME64 StackFrame, 
+    PVOID ContextRecord,
+    PREAD_PROCESS_MEMORY_ROUTINE64 ReadMemoryRoutine,
+    PFUNCTION_TABLE_ACCESS_ROUTINE64 FunctionTableAccessRoutine,
+    PGET_MODULE_BASE_ROUTINE64 GetModuleBaseRoutine,
+    PTRANSLATE_ADDRESS_ROUTINE64 TranslateAddress );
+  tSW pSW;
+
+  // UnDecorateSymbolName()
+  typedef DWORD (__stdcall WINAPI *tUDSN)( PCSTR DecoratedName, PSTR UnDecoratedName,
+    DWORD UndecoratedLength, DWORD Flags );
+  tUDSN pUDSN;
+
+  typedef BOOL (__stdcall WINAPI *tSGSP)(HANDLE hProcess, PSTR SearchPath, DWORD SearchPathLength);
+  tSGSP pSGSP;
+
+
+private:
+  // **************************************** ToolHelp32 ************************
+  #define MAX_MODULE_NAME32 255
+  #define TH32CS_SNAPMODULE   0x00000008
+  #pragma pack( push, 8 )
+  typedef struct tagMODULEENTRY32
+  {
+      DWORD   dwSize;
+      DWORD   th32ModuleID;       // This module
+      DWORD   th32ProcessID;      // owning process
+      DWORD   GlblcntUsage;       // Global usage count on the module
+      DWORD   ProccntUsage;       // Module usage count in th32ProcessID's context
+      BYTE  * modBaseAddr;        // Base address of module in th32ProcessID's context
+      DWORD   modBaseSize;        // Size in bytes of module starting at modBaseAddr
+      HMODULE hModule;            // The hModule of this module in th32ProcessID's context
+      char    szModule[MAX_MODULE_NAME32 + 1];
+      char    szExePath[MAX_PATH];
+  } MODULEENTRY32;
+  typedef MODULEENTRY32 *  PMODULEENTRY32;
+  typedef MODULEENTRY32 *  LPMODULEENTRY32;
+  #pragma pack( pop )
+
+  BOOL GetModuleListTH32(HANDLE hProcess, DWORD pid)
+  {
+    // CreateToolhelp32Snapshot()
+    typedef HANDLE (__stdcall *tCT32S)(DWORD dwFlags, DWORD th32ProcessID);
+    // Module32First()
+    typedef BOOL (__stdcall *tM32F)(HANDLE hSnapshot, LPMODULEENTRY32 lpme);
+    // Module32Next()
+    typedef BOOL (__stdcall *tM32N)(HANDLE hSnapshot, LPMODULEENTRY32 lpme);
+
+    // try both dlls...
+    const TCHAR *dllname[] = { _T("kernel32.dll"), _T("tlhelp32.dll") };
+    HINSTANCE hToolhelp = NULL;
+    tCT32S pCT32S = NULL;
+    tM32F pM32F = NULL;
+    tM32N pM32N = NULL;
+
+    HANDLE hSnap;
+    MODULEENTRY32 me;
+    me.dwSize = sizeof(me);
+    BOOL keepGoing;
+    size_t i;
+
+    for (i = 0; i<(sizeof(dllname) / sizeof(dllname[0])); i++ )
+    {
+      hToolhelp = LoadLibrary( dllname[i] );
+      if (hToolhelp == NULL)
+        continue;
+      pCT32S = (tCT32S) GetProcAddress(hToolhelp, "CreateToolhelp32Snapshot");
+      pM32F = (tM32F) GetProcAddress(hToolhelp, "Module32First");
+      pM32N = (tM32N) GetProcAddress(hToolhelp, "Module32Next");
+      if ( (pCT32S != NULL) && (pM32F != NULL) && (pM32N != NULL) )
+        break; // found the functions!
+      FreeLibrary(hToolhelp);
+      hToolhelp = NULL;
+    }
+
+    if (hToolhelp == NULL)
+      return FALSE;
+
+    hSnap = pCT32S( TH32CS_SNAPMODULE, pid );
+    if (hSnap == (HANDLE) -1)
+    {
+      FreeLibrary(hToolhelp);
+      return FALSE;
+    }
+
+    keepGoing = !!pM32F( hSnap, &me );
+    int cnt = 0;
+    while (keepGoing)
+    {
+      this->LoadModule(hProcess, me.szExePath, me.szModule, (DWORD64) me.modBaseAddr, me.modBaseSize);
+      cnt++;
+      keepGoing = !!pM32N( hSnap, &me );
+    }
+    CloseHandle(hSnap);
+    FreeLibrary(hToolhelp);
+    if (cnt <= 0)
+      return FALSE;
+    return TRUE;
+  }  // GetModuleListTH32
+
+  // **************************************** PSAPI ************************
+  typedef struct _MODULEINFO {
+      LPVOID lpBaseOfDll;
+      DWORD SizeOfImage;
+      LPVOID EntryPoint;
+  } MODULEINFO, *LPMODULEINFO;
+
+  BOOL GetModuleListPSAPI(HANDLE hProcess)
+  {
+    // EnumProcessModules()
+    typedef BOOL (__stdcall *tEPM)(HANDLE hProcess, HMODULE *lphModule, DWORD cb, LPDWORD lpcbNeeded );
+    // GetModuleFileNameEx()
+    typedef DWORD (__stdcall *tGMFNE)(HANDLE hProcess, HMODULE hModule, LPSTR lpFilename, DWORD nSize );
+    // GetModuleBaseName()
+    typedef DWORD (__stdcall *tGMBN)(HANDLE hProcess, HMODULE hModule, LPSTR lpFilename, DWORD nSize );
+    // GetModuleInformation()
+    typedef BOOL (__stdcall *tGMI)(HANDLE hProcess, HMODULE hModule, LPMODULEINFO pmi, DWORD nSize );
+
+    HINSTANCE hPsapi;
+    tEPM pEPM;
+    tGMFNE pGMFNE;
+    tGMBN pGMBN;
+    tGMI pGMI;
+
+    DWORD i;
+    //ModuleEntry e;
+    DWORD cbNeeded;
+    MODULEINFO mi;
+    HMODULE *hMods = 0;
+    char *tt = NULL;
+    char *tt2 = NULL;
+    const SIZE_T TTBUFLEN = 8096;
+    int cnt = 0;
+
+    hPsapi = LoadLibrary( _T("psapi.dll") );
+    if (hPsapi == NULL)
+      return FALSE;
+
+    pEPM = (tEPM) GetProcAddress( hPsapi, "EnumProcessModules" );
+    pGMFNE = (tGMFNE) GetProcAddress( hPsapi, "GetModuleFileNameExA" );
+    pGMBN = (tGMFNE) GetProcAddress( hPsapi, "GetModuleBaseNameA" );
+    pGMI = (tGMI) GetProcAddress( hPsapi, "GetModuleInformation" );
+    if ( (pEPM == NULL) || (pGMFNE == NULL) || (pGMBN == NULL) || (pGMI == NULL) )
+    {
+      // we couldnīt find all functions
+      FreeLibrary(hPsapi);
+      return FALSE;
+    }
+
+    hMods = (HMODULE*) malloc(sizeof(HMODULE) * (TTBUFLEN / sizeof(HMODULE)));
+    tt = (char*) malloc(sizeof(char) * TTBUFLEN);
+    tt2 = (char*) malloc(sizeof(char) * TTBUFLEN);
+    if ( (hMods == NULL) || (tt == NULL) || (tt2 == NULL) )
+      goto cleanup;
+
+    if ( ! pEPM( hProcess, hMods, TTBUFLEN, &cbNeeded ) )
+    {
+      //_ftprintf(fLogFile, _T("%lu: EPM failed, GetLastError = %lu\n"), g_dwShowCount, gle );
+      goto cleanup;
+    }
+
+    if ( cbNeeded > TTBUFLEN )
+    {
+      //_ftprintf(fLogFile, _T("%lu: More than %lu module handles. Huh?\n"), g_dwShowCount, lenof( hMods ) );
+      goto cleanup;
+    }
+
+    for ( i = 0; i < cbNeeded / sizeof(hMods[0]); i++ )
+    {
+      // base address, size
+      pGMI(hProcess, hMods[i], &mi, sizeof(mi));
+      // image file name
+      tt[0] = 0;
+      pGMFNE(hProcess, hMods[i], tt, TTBUFLEN );
+      // module name
+      tt2[0] = 0;
+      pGMBN(hProcess, hMods[i], tt2, TTBUFLEN );
+
+      DWORD dwRes = this->LoadModule(hProcess, tt, tt2, (DWORD64) mi.lpBaseOfDll, mi.SizeOfImage);
+      if (dwRes != ERROR_SUCCESS)
+        this->m_parent->OnDbgHelpErr("LoadModule", dwRes, 0);
+      cnt++;
+    }
+
+  cleanup:
+    if (hPsapi != NULL) FreeLibrary(hPsapi);
+    if (tt2 != NULL) free(tt2);
+    if (tt != NULL) free(tt);
+    if (hMods != NULL) free(hMods);
+
+    return cnt != 0;
+  }  // GetModuleListPSAPI
+
+  DWORD LoadModule(HANDLE hProcess, LPCSTR img, LPCSTR mod, DWORD64 baseAddr, DWORD size)
+  {
+    CHAR *szImg = _strdup(img);
+    CHAR *szMod = _strdup(mod);
+    DWORD result = ERROR_SUCCESS;
+    if ( (szImg == NULL) || (szMod == NULL) )
+      result = ERROR_NOT_ENOUGH_MEMORY;
+    else
+    {
+      if (pSLM(hProcess, 0, szImg, szMod, baseAddr, size) == 0)
+        result = GetLastError();
+    }
+    ULONGLONG fileVersion = 0;
+    if ( (m_parent != NULL) && (szImg != NULL) )
+    {
+      // try to retrive the file-version:
+      if ( (this->m_parent->m_options & StackWalker::RetrieveFileVersion) != 0)
+      {
+        VS_FIXEDFILEINFO *fInfo = NULL;
+        DWORD dwHandle;
+        DWORD dwSize = GetFileVersionInfoSizeA(szImg, &dwHandle);
+        if (dwSize > 0)
+        {
+          LPVOID vData = malloc(dwSize);
+          if (vData != NULL)
+          {
+            if (GetFileVersionInfoA(szImg, dwHandle, dwSize, vData) != 0)
+            {
+              UINT len;
+              TCHAR szSubBlock[] = _T("\\");
+              if (VerQueryValue(vData, szSubBlock, (LPVOID*) &fInfo, &len) == 0)
+                fInfo = NULL;
+              else
+              {
+                fileVersion = ((ULONGLONG)fInfo->dwFileVersionLS) + ((ULONGLONG)fInfo->dwFileVersionMS << 32);
+              }
+            }
+            free(vData);
+          }
+        }
+      }
+
+      // Retrive some additional-infos about the module
+      IMAGEHLP_MODULE64_V3 Module;
+      const char *szSymType = "-unknown-";
+      if (this->GetModuleInfo(hProcess, baseAddr, &Module) != FALSE)
+      {
+        switch(Module.SymType)
+        {
+          case SymNone:
+            szSymType = "-nosymbols-";
+            break;
+          case SymCoff:  // 1
+            szSymType = "COFF";
+            break;
+          case SymCv:  // 2
+            szSymType = "CV";
+            break;
+          case SymPdb:  // 3
+            szSymType = "PDB";
+            break;
+          case SymExport:  // 4
+            szSymType = "-exported-";
+            break;
+          case SymDeferred:  // 5
+            szSymType = "-deferred-";
+            break;
+          case SymSym:  // 6
+            szSymType = "SYM";
+            break;
+          case 7: // SymDia:
+            szSymType = "DIA";
+            break;
+          case 8: //SymVirtual:
+            szSymType = "Virtual";
+            break;
+        }
+      }
+      LPCSTR pdbName = Module.LoadedImageName;
+      if (Module.LoadedPdbName[0] != 0)
+        pdbName = Module.LoadedPdbName;
+      this->m_parent->OnLoadModule(img, mod, baseAddr, size, result, szSymType, pdbName, fileVersion);
+    }
+    if (szImg != NULL) free(szImg);
+    if (szMod != NULL) free(szMod);
+    return result;
+  }
+public:
+  BOOL LoadModules(HANDLE hProcess, DWORD dwProcessId)
+  {
+    // first try toolhelp32
+    if (GetModuleListTH32(hProcess, dwProcessId))
+      return true;
+    // then try psapi
+    return GetModuleListPSAPI(hProcess);
+  }
+
+
+  BOOL GetModuleInfo(HANDLE hProcess, DWORD64 baseAddr, IMAGEHLP_MODULE64_V3 *pModuleInfo)
+  {
+    memset(pModuleInfo, 0, sizeof(IMAGEHLP_MODULE64_V3));
+    if(this->pSGMI == NULL)
+    {
+      SetLastError(ERROR_DLL_INIT_FAILED);
+      return FALSE;
+    }
+    // First try to use the larger ModuleInfo-Structure
+    pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V3);
+    void *pData = malloc(4096); // reserve enough memory, so the bug in v6.3.5.1 does not lead to memory-overwrites...
+    if (pData == NULL)
+    {
+      SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+      return FALSE;
+    }
+    memcpy(pData, pModuleInfo, sizeof(IMAGEHLP_MODULE64_V3));
+    static bool s_useV3Version = true;
+    if (s_useV3Version)
+    {
+      if (this->pSGMI(hProcess, baseAddr, (IMAGEHLP_MODULE64_V3*) pData) != FALSE)
+      {
+        // only copy as much memory as is reserved...
+        memcpy(pModuleInfo, pData, sizeof(IMAGEHLP_MODULE64_V3));
+        pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V3);
+        free(pData);
+        return TRUE;
+      }
+      s_useV3Version = false;  // to prevent unneccessarry calls with the larger struct...
+    }
+
+    // could not retrive the bigger structure, try with the smaller one (as defined in VC7.1)...
+    pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V2);
+    memcpy(pData, pModuleInfo, sizeof(IMAGEHLP_MODULE64_V2));
+    if (this->pSGMI(hProcess, baseAddr, (IMAGEHLP_MODULE64_V3*) pData) != FALSE)
+    {
+      // only copy as much memory as is reserved...
+      memcpy(pModuleInfo, pData, sizeof(IMAGEHLP_MODULE64_V2));
+      pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V2);
+      free(pData);
+      return TRUE;
+    }
+    free(pData);
+    SetLastError(ERROR_DLL_INIT_FAILED);
+    return FALSE;
+  }
+};
+
+// #############################################################
+StackWalker::StackWalker(DWORD dwProcessId, HANDLE hProcess)
+{
+  this->m_verbose = true;
+  this->m_options = OptionsAll;
+  this->m_modulesLoaded = FALSE;
+  this->m_hProcess = hProcess;
+  this->m_sw = new StackWalkerInternal(this, this->m_hProcess);
+  this->m_dwProcessId = dwProcessId;
+  this->m_szSymPath = NULL;
+  this->m_MaxRecursionCount = 1000;
+}
+StackWalker::StackWalker(bool verbose, int options, LPCSTR szSymPath, DWORD dwProcessId, HANDLE hProcess)
+{
+  this->m_verbose = verbose;
+  this->m_options = options;
+  this->m_modulesLoaded = FALSE;
+  this->m_hProcess = hProcess;
+  this->m_sw = new StackWalkerInternal(this, this->m_hProcess);
+  this->m_dwProcessId = dwProcessId;
+  if (szSymPath != NULL)
+  {
+    this->m_szSymPath = _strdup(szSymPath);
+    this->m_options |= SymBuildPath;
+  }
+  else
+    this->m_szSymPath = NULL;
+  this->m_MaxRecursionCount = 1000;
+}
+
+StackWalker::~StackWalker()
+{
+  if (m_szSymPath != NULL)
+    free(m_szSymPath);
+  m_szSymPath = NULL;
+  if (this->m_sw != NULL)
+    delete this->m_sw;
+  this->m_sw = NULL;
+}
+
+BOOL StackWalker::LoadModules()
+{
+  if (this->m_sw == NULL)
+  {
+    SetLastError(ERROR_DLL_INIT_FAILED);
+    return FALSE;
+  }
+  if (m_modulesLoaded != FALSE)
+    return TRUE;
+
+  // Build the sym-path:
+  char *szSymPath = NULL;
+  if ( (this->m_options & SymBuildPath) != 0)
+  {
+    const size_t nSymPathLen = 4096;
+    szSymPath = (char*) malloc(nSymPathLen);
+    if (szSymPath == NULL)
+    {
+      SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+      return FALSE;
+    }
+    szSymPath[0] = 0;
+    // Now first add the (optional) provided sympath:
+    if (this->m_szSymPath != NULL)
+    {
+      strcat_s(szSymPath, nSymPathLen, this->m_szSymPath);
+      strcat_s(szSymPath, nSymPathLen, ";");
+    }
+
+    strcat_s(szSymPath, nSymPathLen, ".;");
+
+    const size_t nTempLen = 1024;
+    char szTemp[nTempLen];
+    // Now add the current directory:
+    if (GetCurrentDirectoryA(nTempLen, szTemp) > 0)
+    {
+      szTemp[nTempLen-1] = 0;
+      strcat_s(szSymPath, nSymPathLen, szTemp);
+      strcat_s(szSymPath, nSymPathLen, ";");
+    }
+
+    // Now add the path for the main-module:
+    if (GetModuleFileNameA(NULL, szTemp, nTempLen) > 0)
+    {
+      szTemp[nTempLen-1] = 0;
+      for (char *p = (szTemp+strlen(szTemp)-1); p >= szTemp; --p)
+      {
+        // locate the rightmost path separator
+        if ( (*p == '\\') || (*p == '/') || (*p == ':') )
+        {
+          *p = 0;
+          break;
+        }
+      }  // for (search for path separator...)
+      if (strlen(szTemp) > 0)
+      {
+        strcat_s(szSymPath, nSymPathLen, szTemp);
+        strcat_s(szSymPath, nSymPathLen, ";");
+      }
+    }
+    if (GetEnvironmentVariableA("_NT_SYMBOL_PATH", szTemp, nTempLen) > 0)
+    {
+      szTemp[nTempLen-1] = 0;
+      strcat_s(szSymPath, nSymPathLen, szTemp);
+      strcat_s(szSymPath, nSymPathLen, ";");
+    }
+    if (GetEnvironmentVariableA("_NT_ALTERNATE_SYMBOL_PATH", szTemp, nTempLen) > 0)
+    {
+      szTemp[nTempLen-1] = 0;
+      strcat_s(szSymPath, nSymPathLen, szTemp);
+      strcat_s(szSymPath, nSymPathLen, ";");
+    }
+    if (GetEnvironmentVariableA("SYSTEMROOT", szTemp, nTempLen) > 0)
+    {
+      szTemp[nTempLen-1] = 0;
+      strcat_s(szSymPath, nSymPathLen, szTemp);
+      strcat_s(szSymPath, nSymPathLen, ";");
+      // also add the "system32"-directory:
+      strcat_s(szTemp, nTempLen, "\\system32");
+      strcat_s(szSymPath, nSymPathLen, szTemp);
+      strcat_s(szSymPath, nSymPathLen, ";");
+    }
+
+    if ( (this->m_options & SymUseSymSrv) != 0)
+    {
+      if (GetEnvironmentVariableA("SYSTEMDRIVE", szTemp, nTempLen) > 0)
+      {
+        szTemp[nTempLen-1] = 0;
+        strcat_s(szSymPath, nSymPathLen, "SRV*");
+        strcat_s(szSymPath, nSymPathLen, szTemp);
+        strcat_s(szSymPath, nSymPathLen, "\\websymbols");
+        strcat_s(szSymPath, nSymPathLen, "*http://msdl.microsoft.com/download/symbols;");
+      }
+      else
+        strcat_s(szSymPath, nSymPathLen, "SRV*c:\\websymbols*http://msdl.microsoft.com/download/symbols;");
+    }
+  }  // if SymBuildPath
+
+  // First Init the whole stuff...
+  BOOL bRet = this->m_sw->Init(szSymPath);
+  if (szSymPath != NULL) free(szSymPath); szSymPath = NULL;
+  if (bRet == FALSE)
+  {
+    this->OnDbgHelpErr("Error while initializing dbghelp.dll", 0, 0);
+    SetLastError(ERROR_DLL_INIT_FAILED);
+    return FALSE;
+  }
+
+  bRet = this->m_sw->LoadModules(this->m_hProcess, this->m_dwProcessId);
+  if (bRet != FALSE)
+    m_modulesLoaded = TRUE;
+  return bRet;
+}
+
+
+// The following is used to pass the "userData"-Pointer to the user-provided readMemoryFunction
+// This has to be done due to a problem with the "hProcess"-parameter in x64...
+// Because this class is in no case multi-threading-enabled (because of the limitations 
+// of dbghelp.dll) it is "safe" to use a static-variable
+static StackWalker::PReadProcessMemoryRoutine s_readMemoryFunction = NULL;
+static LPVOID s_readMemoryFunction_UserData = NULL;
+
+BOOL StackWalker::ShowCallstack(HANDLE hThread, const CONTEXT *context, PReadProcessMemoryRoutine readMemoryFunction, LPVOID pUserData)
+{
+  CONTEXT c;
+  CallstackEntry csEntry;
+  IMAGEHLP_SYMBOL64 *pSym = NULL;
+  StackWalkerInternal::IMAGEHLP_MODULE64_V3 Module;
+  IMAGEHLP_LINE64 Line;
+  int frameNum;
+  bool bLastEntryCalled = true;
+  int curRecursionCount = 0;
+
+  if (m_modulesLoaded == FALSE)
+    this->LoadModules();  // ignore the result...
+
+  if (this->m_sw->m_hDbhHelp == NULL)
+  {
+    SetLastError(ERROR_DLL_INIT_FAILED);
+    return FALSE;
+  }
+
+  s_readMemoryFunction = readMemoryFunction;
+  s_readMemoryFunction_UserData = pUserData;
+
+  if (context == NULL)
+  {
+    // If no context is provided, capture the context
+    // See: https://stackwalker.codeplex.com/discussions/446958
+#if _WIN32_WINNT <= 0x0501
+      // If we need to support XP, we need to use the "old way", because "GetThreadId" is not available!
+    if (hThread == GetCurrentThread())
+#else
+    if (GetThreadId(hThread) == GetCurrentThreadId())
+#endif
+    {
+      GET_CURRENT_CONTEXT_STACKWALKER_CODEPLEX(c, USED_CONTEXT_FLAGS);
+    }
+    else
+    {
+      SuspendThread(hThread);
+      memset(&c, 0, sizeof(CONTEXT));
+      c.ContextFlags = USED_CONTEXT_FLAGS;
+      if (GetThreadContext(hThread, &c) == FALSE)
+      {
+        ResumeThread(hThread);
+        return FALSE;
+      }
+    }
+  }
+  else
+    c = *context;
+
+  // init STACKFRAME for first call
+  STACKFRAME64 s; // in/out stackframe
+  memset(&s, 0, sizeof(s));
+  DWORD imageType;
+#ifdef _M_IX86
+  // normally, call ImageNtHeader() and use machine info from PE header
+  imageType = IMAGE_FILE_MACHINE_I386;
+  s.AddrPC.Offset = c.Eip;
+  s.AddrPC.Mode = AddrModeFlat;
+  s.AddrFrame.Offset = c.Ebp;
+  s.AddrFrame.Mode = AddrModeFlat;
+  s.AddrStack.Offset = c.Esp;
+  s.AddrStack.Mode = AddrModeFlat;
+#elif _M_X64
+  imageType = IMAGE_FILE_MACHINE_AMD64;
+  s.AddrPC.Offset = c.Rip;
+  s.AddrPC.Mode = AddrModeFlat;
+  s.AddrFrame.Offset = c.Rsp;
+  s.AddrFrame.Mode = AddrModeFlat;
+  s.AddrStack.Offset = c.Rsp;
+  s.AddrStack.Mode = AddrModeFlat;
+#elif _M_IA64
+  imageType = IMAGE_FILE_MACHINE_IA64;
+  s.AddrPC.Offset = c.StIIP;
+  s.AddrPC.Mode = AddrModeFlat;
+  s.AddrFrame.Offset = c.IntSp;
+  s.AddrFrame.Mode = AddrModeFlat;
+  s.AddrBStore.Offset = c.RsBSP;
+  s.AddrBStore.Mode = AddrModeFlat;
+  s.AddrStack.Offset = c.IntSp;
+  s.AddrStack.Mode = AddrModeFlat;
+#else
+#error "Platform not supported!"
+#endif
+
+  pSym = (IMAGEHLP_SYMBOL64 *) malloc(sizeof(IMAGEHLP_SYMBOL64) + STACKWALK_MAX_NAMELEN);
+  if (!pSym) goto cleanup;  // not enough memory...
+  memset(pSym, 0, sizeof(IMAGEHLP_SYMBOL64) + STACKWALK_MAX_NAMELEN);
+  pSym->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
+  pSym->MaxNameLength = STACKWALK_MAX_NAMELEN;
+
+  memset(&Line, 0, sizeof(Line));
+  Line.SizeOfStruct = sizeof(Line);
+
+  memset(&Module, 0, sizeof(Module));
+  Module.SizeOfStruct = sizeof(Module);
+
+  for (frameNum = 0; ; ++frameNum )
+  {
+    // get next stack frame (StackWalk64(), SymFunctionTableAccess64(), SymGetModuleBase64())
+    // if this returns ERROR_INVALID_ADDRESS (487) or ERROR_NOACCESS (998), you can
+    // assume that either you are done, or that the stack is so hosed that the next
+    // deeper frame could not be found.
+    // CONTEXT need not to be suplied if imageTyp is IMAGE_FILE_MACHINE_I386!
+    if ( ! this->m_sw->pSW(imageType, this->m_hProcess, hThread, &s, &c, myReadProcMem, this->m_sw->pSFTA, this->m_sw->pSGMB, NULL) )
+    {
+      // INFO: "StackWalk64" does not set "GetLastError"...
+      this->OnDbgHelpErr("StackWalk64", 0, s.AddrPC.Offset);
+      break;
+    }
+
+    csEntry.offset = s.AddrPC.Offset;
+    csEntry.name[0] = 0;
+    csEntry.undName[0] = 0;
+    csEntry.undFullName[0] = 0;
+    csEntry.offsetFromSmybol = 0;
+    csEntry.offsetFromLine = 0;
+    csEntry.lineFileName[0] = 0;
+    csEntry.lineNumber = 0;
+    csEntry.loadedImageName[0] = 0;
+    csEntry.moduleName[0] = 0;
+    if (s.AddrPC.Offset == s.AddrReturn.Offset)
+    {
+      if ( (this->m_MaxRecursionCount > 0) && (curRecursionCount > m_MaxRecursionCount) )
+      {
+        this->OnDbgHelpErr("StackWalk64-Endless-Callstack!", 0, s.AddrPC.Offset);
+        break;
+      }
+      curRecursionCount++;
+    }
+    else
+      curRecursionCount = 0;
+    if (s.AddrPC.Offset != 0)
+    {
+      // we seem to have a valid PC
+      // show procedure info (SymGetSymFromAddr64())
+      if (this->m_sw->pSGSFA(this->m_hProcess, s.AddrPC.Offset, &(csEntry.offsetFromSmybol), pSym) != FALSE)
+      {
+        MyStrCpy(csEntry.name, STACKWALK_MAX_NAMELEN, pSym->Name);
+        // UnDecorateSymbolName()
+        this->m_sw->pUDSN( pSym->Name, csEntry.undName, STACKWALK_MAX_NAMELEN, UNDNAME_NAME_ONLY );
+        this->m_sw->pUDSN( pSym->Name, csEntry.undFullName, STACKWALK_MAX_NAMELEN, UNDNAME_COMPLETE );
+      }
+      else
+      {
+        this->OnDbgHelpErr("SymGetSymFromAddr64", GetLastError(), s.AddrPC.Offset);
+      }
+
+      // show line number info, NT5.0-method (SymGetLineFromAddr64())
+      if (this->m_sw->pSGLFA != NULL )
+      { // yes, we have SymGetLineFromAddr64()
+        if (this->m_sw->pSGLFA(this->m_hProcess, s.AddrPC.Offset, &(csEntry.offsetFromLine), &Line) != FALSE)
+        {
+          csEntry.lineNumber = Line.LineNumber;
+          MyStrCpy(csEntry.lineFileName, STACKWALK_MAX_NAMELEN, Line.FileName);
+        }
+        else
+        {
+          this->OnDbgHelpErr("SymGetLineFromAddr64", GetLastError(), s.AddrPC.Offset);
+        }
+      } // yes, we have SymGetLineFromAddr64()
+
+      if (m_verbose) // getting module info is very slow, skip unless we're being verbose.
+      {
+          // show module info (SymGetModuleInfo64())
+          if (this->m_sw->GetModuleInfo(this->m_hProcess, s.AddrPC.Offset, &Module ) != FALSE)
+          { // got module info OK
+              switch ( Module.SymType )
+              {
+                  case SymNone:
+                  csEntry.symTypeString = "-nosymbols-";
+                  break;
+                  case SymCoff:
+                  csEntry.symTypeString = "COFF";
+                  break;
+                  case SymCv:
+                  csEntry.symTypeString = "CV";
+                  break;
+                  case SymPdb:
+                  csEntry.symTypeString = "PDB";
+                  break;
+                  case SymExport:
+                  csEntry.symTypeString = "-exported-";
+                  break;
+                  case SymDeferred:
+                  csEntry.symTypeString = "-deferred-";
+                  break;
+                  case SymSym:
+                  csEntry.symTypeString = "SYM";
+                  break;
+#if API_VERSION_NUMBER >= 9
+                  case SymDia:
+                  csEntry.symTypeString = "DIA";
+                  break;
+#endif
+                  case 8: //SymVirtual:
+                  csEntry.symTypeString = "Virtual";
+                  break;
+                  default:
+                  //_snprintf( ty, sizeof(ty), "symtype=%ld", (long) Module.SymType );
+                  csEntry.symTypeString = NULL;
+                  break;
+              }
+        
+              MyStrCpy(csEntry.moduleName, STACKWALK_MAX_NAMELEN, Module.ModuleName);
+              csEntry.baseOfImage = Module.BaseOfImage;
+              MyStrCpy(csEntry.loadedImageName, STACKWALK_MAX_NAMELEN, Module.LoadedImageName);
+          } // got module info OK
+          else
+          {
+              this->OnDbgHelpErr("SymGetModuleInfo64", GetLastError(), s.AddrPC.Offset);
+          }
+      }
+      else
+      {
+          MyStrCpy(csEntry.moduleName, STACKWALK_MAX_NAMELEN, "MODULE?");
+      }
+    } // we seem to have a valid PC
+
+    CallstackEntryType et = nextEntry;
+    if (frameNum == 0)
+      et = firstEntry;
+    bLastEntryCalled = false;
+    this->OnCallstackEntry(et, csEntry);
+    
+    if (s.AddrReturn.Offset == 0)
+    {
+      bLastEntryCalled = true;
+      this->OnCallstackEntry(lastEntry, csEntry);
+      SetLastError(ERROR_SUCCESS);
+      break;
+    }
+  } // for ( frameNum )
+
+  cleanup:
+    if (pSym) free( pSym );
+
+  if (bLastEntryCalled == false)
+      this->OnCallstackEntry(lastEntry, csEntry);
+
+  if (context == NULL)
+    ResumeThread(hThread);
+
+  return TRUE;
+}
+
+BOOL __stdcall StackWalker::myReadProcMem(
+    HANDLE      hProcess,
+    DWORD64     qwBaseAddress,
+    PVOID       lpBuffer,
+    DWORD       nSize,
+    LPDWORD     lpNumberOfBytesRead
+    )
+{
+  if (s_readMemoryFunction == NULL)
+  {
+    SIZE_T st;
+    BOOL bRet = ReadProcessMemory(hProcess, (LPVOID) qwBaseAddress, lpBuffer, nSize, &st);
+    *lpNumberOfBytesRead = (DWORD) st;
+    //printf("ReadMemory: hProcess: %p, baseAddr: %p, buffer: %p, size: %d, read: %d, result: %d\n", hProcess, (LPVOID) qwBaseAddress, lpBuffer, nSize, (DWORD) st, (DWORD) bRet);
+    return bRet;
+  }
+  else
+  {
+    return s_readMemoryFunction(hProcess, qwBaseAddress, lpBuffer, nSize, lpNumberOfBytesRead, s_readMemoryFunction_UserData);
+  }
+}
+
+void StackWalker::OnLoadModule(LPCSTR img, LPCSTR mod, DWORD64 baseAddr, DWORD size, DWORD result, LPCSTR symType, LPCSTR pdbName, ULONGLONG fileVersion)
+{
+  CHAR buffer[STACKWALK_MAX_NAMELEN];
+  if (fileVersion == 0)
+    _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "%s:%s (%p), size: %d (result: %d), SymType: '%s', PDB: '%s'\n", img, mod, (LPVOID) baseAddr, size, result, symType, pdbName);
+  else
+  {
+    DWORD v4 = (DWORD) (fileVersion & 0xFFFF);
+    DWORD v3 = (DWORD) ((fileVersion>>16) & 0xFFFF);
+    DWORD v2 = (DWORD) ((fileVersion>>32) & 0xFFFF);
+    DWORD v1 = (DWORD) ((fileVersion>>48) & 0xFFFF);
+    _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "%s:%s (%p), size: %d (result: %d), SymType: '%s', PDB: '%s', fileVersion: %d.%d.%d.%d\n", img, mod, (LPVOID) baseAddr, size, result, symType, pdbName, v1, v2, v3, v4);
+  }
+  if (m_verbose)
+  {
+      OnOutput(buffer);
+  }
+}
+
+void StackWalker::OnCallstackEntry(CallstackEntryType eType, CallstackEntry &entry)
+{
+  CHAR buffer[STACKWALK_MAX_NAMELEN];
+  if ( (eType != lastEntry) && (entry.offset != 0) )
+  {
+    if (entry.name[0] == 0)
+      MyStrCpy(entry.name, STACKWALK_MAX_NAMELEN, "(function-name not available)");
+    if (entry.undName[0] != 0)
+      MyStrCpy(entry.name, STACKWALK_MAX_NAMELEN, entry.undName);
+    if (entry.undFullName[0] != 0)
+      MyStrCpy(entry.name, STACKWALK_MAX_NAMELEN, entry.undFullName);
+    if (entry.lineFileName[0] == 0)
+    {
+      MyStrCpy(entry.lineFileName, STACKWALK_MAX_NAMELEN, "(filename not available)");
+      if (entry.moduleName[0] == 0)
+        MyStrCpy(entry.moduleName, STACKWALK_MAX_NAMELEN, "(module-name not available)");
+      _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "%p (%s): %s: %s\n", (LPVOID) entry.offset, entry.moduleName, entry.lineFileName, entry.name);
+    }
+    else
+      _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "%s (%d): %s\n", entry.lineFileName, entry.lineNumber, entry.name);
+    buffer[STACKWALK_MAX_NAMELEN-1] = 0;
+    OnOutput(buffer);
+  }
+}
+
+void StackWalker::OnDbgHelpErr(LPCSTR szFuncName, DWORD gle, DWORD64 addr)
+{
+  CHAR buffer[STACKWALK_MAX_NAMELEN];
+  _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "ERROR: %s, GetLastError: %d (Address: %p)\n", szFuncName, gle, (LPVOID) addr);
+  if (m_verbose)
+  {
+      OnOutput(buffer);
+  }
+}
+
+#pragma warning (disable : 4996)
+
+void StackWalker::OnSymInit(LPCSTR szSearchPath, DWORD symOptions, LPCSTR szUserName)
+{
+  CHAR buffer[STACKWALK_MAX_NAMELEN];
+  _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "SymInit: Symbol-SearchPath: '%s', symOptions: %d, UserName: '%s'\n", szSearchPath, symOptions, szUserName);
+  if (m_verbose)
+  {
+      OnOutput(buffer);
+  }
+  // Also display the OS-version
+#if _MSC_VER <= 1200
+  OSVERSIONINFOA ver;
+  ZeroMemory(&ver, sizeof(OSVERSIONINFOA));
+  ver.dwOSVersionInfoSize = sizeof(ver);
+  if (GetVersionExA(&ver) != FALSE)
+  {
+    _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "OS-Version: %d.%d.%d (%s)\n", 
+      ver.dwMajorVersion, ver.dwMinorVersion, ver.dwBuildNumber,
+      ver.szCSDVersion);
+    if (m_verbose)
+    {
+        OnOutput(buffer);
+    }
+  }
+#else
+  OSVERSIONINFOEXA ver;
+  ZeroMemory(&ver, sizeof(OSVERSIONINFOEXA));
+  ver.dwOSVersionInfoSize = sizeof(ver);
+  if (GetVersionExA( (OSVERSIONINFOA*) &ver) != FALSE)
+  {
+    _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "OS-Version: %d.%d.%d (%s) 0x%x-0x%x\n", 
+      ver.dwMajorVersion, ver.dwMinorVersion, ver.dwBuildNumber,
+      ver.szCSDVersion, ver.wSuiteMask, ver.wProductType);
+    if (m_verbose)
+    {
+        OnOutput(buffer);
+    }
+  }
+#endif
+}
+
+void StackWalker::OnOutput(LPCSTR buffer)
+{
+  OutputDebugStringA(buffer);
+}
+
+#endif // LL_WINDOWS
diff --git a/indra/llcommon/StackWalker.h b/indra/llcommon/StackWalker.h
new file mode 100644
index 0000000000..f4ef8d557f
--- /dev/null
+++ b/indra/llcommon/StackWalker.h
@@ -0,0 +1,223 @@
+/**********************************************************************
+ * 
+ * StackWalker.h
+ *
+ *
+ *
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ *
+ * LICENSE (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ *   Copyright (c) 2005-2009, Jochen Kalmbach
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without modification, 
+ *   are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, 
+ *   this list of conditions and the following disclaimer. 
+ *   Redistributions in binary form must reproduce the above copyright notice, 
+ *   this list of conditions and the following disclaimer in the documentation 
+ *   and/or other materials provided with the distribution. 
+ *   Neither the name of Jochen Kalmbach nor the names of its contributors may be 
+ *   used to endorse or promote products derived from this software without 
+ *   specific prior written permission. 
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+ *   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
+ *   THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ *   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 
+ *   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
+ *   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+ *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 
+ *   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
+ *   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * **********************************************************************/
+
+#if LL_WINDOWS
+
+// #pragma once is supported starting with _MCS_VER 1000, 
+// so we need not to check the version (because we only support _MSC_VER >= 1100)!
+#pragma once
+
+#include <windows.h>
+
+// special defines for VC5/6 (if no actual PSDK is installed):
+#if _MSC_VER < 1300
+typedef unsigned __int64 DWORD64, *PDWORD64;
+#if defined(_WIN64)
+typedef unsigned __int64 SIZE_T, *PSIZE_T;
+#else
+typedef unsigned long SIZE_T, *PSIZE_T;
+#endif
+#endif  // _MSC_VER < 1300
+
+class StackWalkerInternal;  // forward
+class StackWalker
+{
+public:
+  typedef enum StackWalkOptions
+  {
+    // No addition info will be retrived 
+    // (only the address is available)
+    RetrieveNone = 0,
+    
+    // Try to get the symbol-name
+    RetrieveSymbol = 1,
+    
+    // Try to get the line for this symbol
+    RetrieveLine = 2,
+    
+    // Try to retrieve the module-infos
+    RetrieveModuleInfo = 4,
+    
+    // Also retrieve the version for the DLL/EXE
+    RetrieveFileVersion = 8,
+    
+    // Contains all the abouve
+    RetrieveVerbose = 0xF,
+    
+    // Generate a "good" symbol-search-path
+    SymBuildPath = 0x10,
+    
+    // Also use the public Microsoft-Symbol-Server
+    SymUseSymSrv = 0x20,
+    
+    // Contains all the abouve "Sym"-options
+    SymAll = 0x30,
+    
+    // Contains all options (default)
+    OptionsAll = 0x3F
+  } StackWalkOptions;
+
+  StackWalker(
+    bool verbose = true,
+    int options = OptionsAll, // 'int' is by design, to combine the enum-flags
+    LPCSTR szSymPath = NULL, 
+    DWORD dwProcessId = GetCurrentProcessId(), 
+    HANDLE hProcess = GetCurrentProcess()
+    );
+  StackWalker(DWORD dwProcessId, HANDLE hProcess);
+  virtual ~StackWalker();
+
+  typedef BOOL (__stdcall *PReadProcessMemoryRoutine)(
+    HANDLE      hProcess,
+    DWORD64     qwBaseAddress,
+    PVOID       lpBuffer,
+    DWORD       nSize,
+    LPDWORD     lpNumberOfBytesRead,
+    LPVOID      pUserData  // optional data, which was passed in "ShowCallstack"
+    );
+
+  BOOL LoadModules();
+
+  BOOL ShowCallstack(
+    HANDLE hThread = GetCurrentThread(), 
+    const CONTEXT *context = NULL, 
+    PReadProcessMemoryRoutine readMemoryFunction = NULL,
+    LPVOID pUserData = NULL  // optional to identify some data in the 'readMemoryFunction'-callback
+    );
+
+#if _MSC_VER >= 1300
+// due to some reasons, the "STACKWALK_MAX_NAMELEN" must be declared as "public" 
+// in older compilers in order to use it... starting with VC7 we can declare it as "protected"
+protected:
+#endif
+	enum { STACKWALK_MAX_NAMELEN = 1024 }; // max name length for found symbols
+
+protected:
+  // Entry for each Callstack-Entry
+  typedef struct CallstackEntry
+  {
+    DWORD64 offset;  // if 0, we have no valid entry
+    CHAR name[STACKWALK_MAX_NAMELEN];
+    CHAR undName[STACKWALK_MAX_NAMELEN];
+    CHAR undFullName[STACKWALK_MAX_NAMELEN];
+    DWORD64 offsetFromSmybol;
+    DWORD offsetFromLine;
+    DWORD lineNumber;
+    CHAR lineFileName[STACKWALK_MAX_NAMELEN];
+    DWORD symType;
+    LPCSTR symTypeString;
+    CHAR moduleName[STACKWALK_MAX_NAMELEN];
+    DWORD64 baseOfImage;
+    CHAR loadedImageName[STACKWALK_MAX_NAMELEN];
+  } CallstackEntry;
+
+  typedef enum CallstackEntryType {firstEntry, nextEntry, lastEntry};
+
+  virtual void OnSymInit(LPCSTR szSearchPath, DWORD symOptions, LPCSTR szUserName);
+  virtual void OnLoadModule(LPCSTR img, LPCSTR mod, DWORD64 baseAddr, DWORD size, DWORD result, LPCSTR symType, LPCSTR pdbName, ULONGLONG fileVersion);
+  virtual void OnCallstackEntry(CallstackEntryType eType, CallstackEntry &entry);
+  virtual void OnDbgHelpErr(LPCSTR szFuncName, DWORD gle, DWORD64 addr);
+  virtual void OnOutput(LPCSTR szText);
+
+  StackWalkerInternal *m_sw;
+  HANDLE m_hProcess;
+  DWORD m_dwProcessId;
+  BOOL m_modulesLoaded;
+  LPSTR m_szSymPath;
+
+  bool m_verbose;
+  int m_options;
+  int m_MaxRecursionCount;
+
+  static BOOL __stdcall myReadProcMem(HANDLE hProcess, DWORD64 qwBaseAddress, PVOID lpBuffer, DWORD nSize, LPDWORD lpNumberOfBytesRead);
+
+  friend StackWalkerInternal;
+};  // class StackWalker
+
+
+// The "ugly" assembler-implementation is needed for systems before XP
+// If you have a new PSDK and you only compile for XP and later, then you can use 
+// the "RtlCaptureContext"
+// Currently there is no define which determines the PSDK-Version... 
+// So we just use the compiler-version (and assumes that the PSDK is 
+// the one which was installed by the VS-IDE)
+
+// INFO: If you want, you can use the RtlCaptureContext if you only target XP and later...
+//       But I currently use it in x64/IA64 environments...
+//#if defined(_M_IX86) && (_WIN32_WINNT <= 0x0500) && (_MSC_VER < 1400)
+
+#if defined(_M_IX86)
+#ifdef CURRENT_THREAD_VIA_EXCEPTION
+// TODO: The following is not a "good" implementation, 
+// because the callstack is only valid in the "__except" block...
+#define GET_CURRENT_CONTEXT_STACKWALKER_CODEPLEX(c, contextFlags) \
+  do { \
+    memset(&c, 0, sizeof(CONTEXT)); \
+    EXCEPTION_POINTERS *pExp = NULL; \
+    __try { \
+      throw 0; \
+    } __except( ( (pExp = GetExceptionInformation()) ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_EXECUTE_HANDLER)) {} \
+    if (pExp != NULL) \
+      memcpy(&c, pExp->ContextRecord, sizeof(CONTEXT)); \
+      c.ContextFlags = contextFlags; \
+  } while(0);
+#else
+// The following should be enough for walking the callstack...
+#define GET_CURRENT_CONTEXT_STACKWALKER_CODEPLEX(c, contextFlags) \
+  do { \
+    memset(&c, 0, sizeof(CONTEXT)); \
+    c.ContextFlags = contextFlags; \
+    __asm    call x \
+    __asm x: pop eax \
+    __asm    mov c.Eip, eax \
+    __asm    mov c.Ebp, ebp \
+    __asm    mov c.Esp, esp \
+  } while(0);
+#endif
+
+#else
+
+// The following is defined for x86 (XP and higher), x64 and IA64:
+#define GET_CURRENT_CONTEXT_STACKWALKER_CODEPLEX(c, contextFlags) \
+  do { \
+    memset(&c, 0, sizeof(CONTEXT)); \
+    c.ContextFlags = contextFlags; \
+    RtlCaptureContext(&c); \
+} while(0);
+#endif
+
+#endif // LL_WINDOWS
diff --git a/indra/llcommon/llcallstack.cpp b/indra/llcommon/llcallstack.cpp
new file mode 100644
index 0000000000..87eb37de16
--- /dev/null
+++ b/indra/llcommon/llcallstack.cpp
@@ -0,0 +1,93 @@
+/** 
+ * @file llcallstack.cpp
+ * @brief run-time extraction of the current callstack
+ *
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2016, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "llcommon.h"
+#include "llcallstack.h"
+#include "StackWalker.h"
+
+#if LL_WINDOWS
+class LLCallStackImpl: public StackWalker
+{
+public:
+    LLCallStackImpl():
+        StackWalker(false,0) // non-verbose, options = 0
+    {
+    }
+    ~LLCallStackImpl()
+    {
+    }
+    void getStack(std::vector<std::string>& stack)
+    {
+        m_stack.clear();
+        ShowCallstack();
+        // Skip the first 2 lines because they're just bookkeeping for LLCallStack.
+        for (S32 i=3; i<m_stack.size(); ++i)
+        {
+            stack.push_back(m_stack[i]);
+        }
+    }
+protected:
+    virtual void OnOutput(LPCSTR szText)
+    {
+        m_stack.push_back(szText);
+    }
+    std::vector<std::string> m_stack;
+};
+#else
+// Stub - not implemented currently on other platforms.
+class LLCallStackImpl
+{
+public:
+    LLCallStackImpl() {}
+    ~LLCallStackImpl() {}
+    void getStack(std::vector<std::string>& stack)
+    {
+        stack.clear();
+    }
+};
+#endif
+
+LLCallStackImpl *LLCallStack::s_impl = NULL;
+
+LLCallStack::LLCallStack()
+{
+    if (!s_impl)
+    {
+        s_impl = new LLCallStackImpl;
+    }
+    LLTimer t;
+    s_impl->getStack(m_strings);
+}
+
+std::ostream& operator<<(std::ostream& s, const LLCallStack& call_stack)
+{
+    std::vector<std::string>::const_iterator it;
+    for (it=call_stack.m_strings.begin(); it!=call_stack.m_strings.end(); ++it)
+    {
+        s << *it;
+    }
+    return s;
+}
diff --git a/indra/llcommon/llcallstack.h b/indra/llcommon/llcallstack.h
new file mode 100644
index 0000000000..6059d4f2c5
--- /dev/null
+++ b/indra/llcommon/llcallstack.h
@@ -0,0 +1,38 @@
+/** 
+ * @file llcallstack.h
+ * @brief run-time extraction of the current callstack
+ *
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2016, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+class LLCallStackImpl;
+
+class LLCallStack
+{
+public:
+    LLCallStack();
+    std::vector<std::string> m_strings;
+private:
+    static LLCallStackImpl *s_impl;
+};
+
+LL_COMMON_API std::ostream& operator<<(std::ostream& s, const LLCallStack& call_stack);
diff --git a/indra/newview/llstartup.cpp b/indra/newview/llstartup.cpp
index 9d1a12f18a..d62cf3caab 100755
--- a/indra/newview/llstartup.cpp
+++ b/indra/newview/llstartup.cpp
@@ -28,6 +28,7 @@
 
 #include "llappviewer.h"
 #include "llstartup.h"
+#include "llcallstack.h"
 
 #if LL_WINDOWS
 #	include <process.h>		// _spawnl()
@@ -197,6 +198,8 @@
 #include "lltoolbarview.h"
 #include "llexperiencelog.h"
 
+#include "llstacktrace.h"
+
 #if LL_WINDOWS
 #include "lldxhardware.h"
 #endif
diff --git a/indra/newview/llvoavatarself.cpp b/indra/newview/llvoavatarself.cpp
index bea3ea2680..0648ee6732 100755
--- a/indra/newview/llvoavatarself.cpp
+++ b/indra/newview/llvoavatarself.cpp
@@ -65,6 +65,7 @@
 #include "llsdutil.h"
 #include "llstartup.h"
 #include "llsdserialize.h"
+#include "llcallstack.h"
 
 #if LL_MSVC
 // disable boost::lexical_cast warning
@@ -205,6 +206,10 @@ bool update_avatar_rez_metrics()
 		return true;
 	
 	gAgentAvatarp->updateAvatarRezMetrics(false);
+
+    LLCallStack cs;
+    LL_INFOS() << "CallStack:\n" << cs << LL_ENDL;
+    
 	return false;
 }