Merge pull request #1723 from secondlife/brad/maint-a-merge-to-gltf-dev

maint a merge to gltf dev

31 files changed, 255 insertions, 268 deletions

diff --git a/indra/llcommon/StackWalker.cpp b/indra/llcommon/StackWalker.cpp
index 2c1bc47d0e..e9ae1723fb 100644
--- a/indra/llcommon/StackWalker.cpp
+++ b/indra/llcommon/StackWalker.cpp
@@ -1,5 +1,5 @@
 /**********************************************************************
- * 
+ *
  * StackWalker.cpp
  * http://stackwalker.codeplex.com/
  *
@@ -13,14 +13,14 @@
  *                       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 
+ *  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, 
+ *                     - 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
@@ -60,26 +60,26 @@
  *   Copyright (c) 2005-2013, Jochen Kalmbach
  *   All rights reserved.
  *
- *   Redistribution and use in source and binary forms, with or without modification, 
+ *   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 
+ *   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.
  *
  **********************************************************************/
@@ -234,7 +234,7 @@ DWORD64
 // Some missing defines (for VC5/6):
 #ifndef INVALID_FILE_ATTRIBUTES
 #define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
-#endif  
+#endif
 
 
 // secure-CRT_functions are only available starting with VC8
@@ -396,7 +396,7 @@ public:
       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;
@@ -512,11 +512,11 @@ struct IMAGEHLP_MODULE64_V2 {
   tSSO pSSO;
 
   // StackWalk64()
-  typedef BOOL (__stdcall *tSW)( 
-    DWORD MachineType, 
+  typedef BOOL (__stdcall *tSW)(
+    DWORD MachineType,
     HANDLE hProcess,
-    HANDLE hThread, 
-    LPSTACKFRAME64 StackFrame, 
+    HANDLE hThread,
+    LPSTACKFRAME64 StackFrame,
     PVOID ContextRecord,
     PREAD_PROCESS_MEMORY_ROUTINE64 ReadMemoryRoutine,
     PFUNCTION_TABLE_ACCESS_ROUTINE64 FunctionTableAccessRoutine,
@@ -1012,7 +1012,7 @@ bool StackWalker::LoadModules()
 
 // 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 
+// 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;
@@ -1222,7 +1222,7 @@ bool StackWalker::ShowCallstack(bool verbose, HANDLE hThread, const CONTEXT *con
                   csEntry.symTypeString = NULL;
                   break;
               }
-        
+
               MyStrCpy(csEntry.moduleName, STACKWALK_MAX_NAMELEN, Module.ModuleName);
               csEntry.baseOfImage = Module.BaseOfImage;
               MyStrCpy(csEntry.loadedImageName, STACKWALK_MAX_NAMELEN, Module.LoadedImageName);
@@ -1243,7 +1243,7 @@ bool StackWalker::ShowCallstack(bool verbose, HANDLE hThread, const CONTEXT *con
       et = firstEntry;
     bLastEntryCalled = false;
     this->OnCallstackEntry(et, csEntry);
-    
+
     if (s.AddrReturn.Offset == 0)
     {
       bLastEntryCalled = true;
@@ -1358,7 +1358,7 @@ void StackWalker::OnSymInit(LPCSTR szSearchPath, DWORD symOptions, LPCSTR szUser
   ver.dwOSVersionInfoSize = sizeof(ver);
   if (GetVersionExA(&ver) != FALSE)
   {
-    _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "OS-Version: %d.%d.%d (%s)\n", 
+    _snprintf_s(buffer, STACKWALK_MAX_NAMELEN, "OS-Version: %d.%d.%d (%s)\n",
       ver.dwMajorVersion, ver.dwMinorVersion, ver.dwBuildNumber,
       ver.szCSDVersion);
     if (m_verbose)
@@ -1372,7 +1372,7 @@ void StackWalker::OnSymInit(LPCSTR szSearchPath, DWORD symOptions, LPCSTR szUser
   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", 
+    _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)
diff --git a/indra/llcommon/is_approx_equal_fraction.h b/indra/llcommon/is_approx_equal_fraction.h
index 732d168986..371a1307c1 100644
--- a/indra/llcommon/is_approx_equal_fraction.h
+++ b/indra/llcommon/is_approx_equal_fraction.h
@@ -5,25 +5,25 @@
  * @brief  lltut.h uses is_approx_equal_fraction(). Moved to this header
  *         file in llcommon so we can use lltut.h for llcommon tests without
  *         making llcommon depend on llmath.
- * 
+ *
  * $LicenseInfo:firstyear=2009&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, 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
  * $/LicenseInfo$
  */
diff --git a/indra/llcommon/llalignedarray.h b/indra/llcommon/llalignedarray.h
index 0ba8b34cb6..8248f82186 100644
--- a/indra/llcommon/llalignedarray.h
+++ b/indra/llcommon/llalignedarray.h
@@ -116,7 +116,7 @@ void LLAlignedArray<T, alignment>::resize(U32 size)
 template <class T, U32 alignment>
 T& LLAlignedArray<T, alignment>::operator[](int idx)
 {
-    if(idx >= mElementCount || idx < 0)
+    if (idx < 0 || unsigned(idx) >= mElementCount)
     {
         LL_ERRS() << "Out of bounds LLAlignedArray, requested: " << (S32)idx << " size: " << mElementCount << LL_ENDL;
     }
@@ -126,7 +126,7 @@ T& LLAlignedArray<T, alignment>::operator[](int idx)
 template <class T, U32 alignment>
 const T& LLAlignedArray<T, alignment>::operator[](int idx) const
 {
-    if (idx >= mElementCount || idx < 0)
+    if (idx < 0 || unsigned(idx) >= mElementCount)
     {
         LL_ERRS() << "Out of bounds LLAlignedArray, requested: " << (S32)idx << " size: " << mElementCount << LL_ENDL;
     }
diff --git a/indra/llcommon/llapp.cpp b/indra/llcommon/llapp.cpp
index 64497df875..b85bd2573b 100644
--- a/indra/llcommon/llapp.cpp
+++ b/indra/llcommon/llapp.cpp
@@ -199,9 +199,9 @@ bool LLApp::parseCommandOptions(int argc, char** argv)
 
 #if LL_WINDOWS
         //Windows changed command line parsing.  Deal with it.
-        S32 slen = value.length() - 1;
-        S32 start = 0;
-        S32 end = slen;
+        size_t slen = value.length() - 1;
+        size_t start = 0;
+        size_t end = slen;
         if (argv[ii][start]=='"')start++;
         if (argv[ii][end]=='"')end--;
         if (start!=0 || end!=slen)
@@ -264,9 +264,9 @@ bool LLApp::parseCommandOptions(int argc, wchar_t** wargv)
 
 #if LL_WINDOWS
         //Windows changed command line parsing.  Deal with it.
-        S32 slen = value.length() - 1;
-        S32 start = 0;
-        S32 end = slen;
+        size_t slen = value.length() - 1;
+        size_t start = 0;
+        size_t end = slen;
         if (wargv[ii][start]=='"')start++;
         if (wargv[ii][end]=='"')end--;
         if (start!=0 || end!=slen)
diff --git a/indra/llcommon/llcoros.cpp b/indra/llcommon/llcoros.cpp
index 23b30bcc57..1539b48bd3 100644
--- a/indra/llcommon/llcoros.cpp
+++ b/indra/llcommon/llcoros.cpp
@@ -3,25 +3,25 @@
  * @author Nat Goodspeed
  * @date   2009-06-03
  * @brief  Implementation for llcoros.
- * 
+ *
  * $LicenseInfo:firstyear=2009&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, 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
  * $/LicenseInfo$
  */
@@ -61,14 +61,14 @@
 #include <excpt.h>
 #endif
 
-// static 
+// static
 bool LLCoros::on_main_coro()
 {
     if (!LLCoros::instanceExists() || LLCoros::getName().empty())
     {
         return true;
     }
-    
+
     return false;
 }
 
diff --git a/indra/llcommon/llcoros.h b/indra/llcommon/llcoros.h
index 00650a2454..369d65407e 100644
--- a/indra/llcommon/llcoros.h
+++ b/indra/llcommon/llcoros.h
@@ -3,25 +3,25 @@
  * @author Nat Goodspeed
  * @date   2009-06-02
  * @brief  Manage running boost::coroutine instances
- * 
+ *
  * $LicenseInfo:firstyear=2009&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, 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
  * $/LicenseInfo$
  */
@@ -100,7 +100,7 @@ public:
     static bool on_main_coro();
 
     // For debugging, return true if on the main thread and not in a coroutine
-    // Non-thread-safe code in the main loop should be protected by 
+    // Non-thread-safe code in the main loop should be protected by
     // llassert(LLCoros::on_main_thread_main_coro())
     static bool on_main_thread_main_coro();
 
@@ -168,7 +168,7 @@ public:
      * LLCoros::launch()).
      */
     static std::string getName();
-    
+
     /**
      * rethrow() is called by the thread's main fiber to propagate an
      * exception from any coroutine into the main fiber, where it can engage
diff --git a/indra/llcommon/lldefs.h b/indra/llcommon/lldefs.h
index 0ba756d472..2fbb26dc1a 100644
--- a/indra/llcommon/lldefs.h
+++ b/indra/llcommon/lldefs.h
@@ -31,64 +31,64 @@
 #include <type_traits>
 
 // Often used array indices
-const U32   VX          = 0;
-const U32   VY          = 1;
-const U32   VZ          = 2;
-const U32   VW          = 3;
-const U32   VS          = 3;
-
-const U32   VRED        = 0;
-const U32   VGREEN      = 1;
-const U32   VBLUE       = 2;
-const U32   VALPHA      = 3;
-
-const U32   INVALID_DIRECTION = 0xFFFFFFFF;
-const U32   EAST        = 0;
-const U32   NORTH       = 1;
-const U32   WEST        = 2;
-const U32   SOUTH       = 3;
-
-const U32   NORTHEAST   = 4;
-const U32   NORTHWEST   = 5;
-const U32   SOUTHWEST   = 6;
-const U32   SOUTHEAST   = 7;
-const U32   MIDDLE      = 8;
-
-const U8    EAST_MASK       = 0x1<<EAST;
-const U8    NORTH_MASK      = 0x1<<NORTH;
-const U8    WEST_MASK       = 0x1<<WEST;
-const U8    SOUTH_MASK      = 0x1<<SOUTH;
-
-const U8    NORTHEAST_MASK  = NORTH_MASK | EAST_MASK;
-const U8    NORTHWEST_MASK  = NORTH_MASK | WEST_MASK;
-const U8    SOUTHWEST_MASK  = SOUTH_MASK | WEST_MASK;
-const U8    SOUTHEAST_MASK  = SOUTH_MASK | EAST_MASK;
-
-const U32 gDirOpposite[8] = {2, 3, 0, 1, 6, 7, 4, 5};
-const U32 gDirAdjacent[8][2] =  {
-                                {4, 7},
-                                {4, 5},
-                                {5, 6},
-                                {6, 7},
-                                {0, 1},
-                                {1, 2},
-                                {2, 3},
-                                {0, 3}
-                                };
+constexpr U32   VX          = 0;
+constexpr U32   VY          = 1;
+constexpr U32   VZ          = 2;
+constexpr U32   VW          = 3;
+constexpr U32   VS          = 3;
+
+constexpr U32   VRED        = 0;
+constexpr U32   VGREEN      = 1;
+constexpr U32   VBLUE       = 2;
+constexpr U32   VALPHA      = 3;
+
+constexpr U32   INVALID_DIRECTION = 0xFFFFFFFF;
+constexpr U32   EAST        = 0;
+constexpr U32   NORTH       = 1;
+constexpr U32   WEST        = 2;
+constexpr U32   SOUTH       = 3;
+
+constexpr U32   NORTHEAST   = 4;
+constexpr U32   NORTHWEST   = 5;
+constexpr U32   SOUTHWEST   = 6;
+constexpr U32   SOUTHEAST   = 7;
+constexpr U32   MIDDLE      = 8;
+
+constexpr U8    EAST_MASK       = 0x1<<EAST;
+constexpr U8    NORTH_MASK      = 0x1<<NORTH;
+constexpr U8    WEST_MASK       = 0x1<<WEST;
+constexpr U8    SOUTH_MASK      = 0x1<<SOUTH;
+
+constexpr U8    NORTHEAST_MASK  = NORTH_MASK | EAST_MASK;
+constexpr U8    NORTHWEST_MASK  = NORTH_MASK | WEST_MASK;
+constexpr U8    SOUTHWEST_MASK  = SOUTH_MASK | WEST_MASK;
+constexpr U8    SOUTHEAST_MASK  = SOUTH_MASK | EAST_MASK;
+
+constexpr U32 gDirOpposite[8] = {2, 3, 0, 1, 6, 7, 4, 5};
+constexpr U32 gDirAdjacent[8][2] =  {
+                                    {4, 7},
+                                    {4, 5},
+                                    {5, 6},
+                                    {6, 7},
+                                    {0, 1},
+                                    {1, 2},
+                                    {2, 3},
+                                    {0, 3}
+                                    };
 
 // Magnitude along the x and y axis
-const S32 gDirAxes[8][2] = {
-                            { 1, 0}, // east
-                            { 0, 1}, // north
-                            {-1, 0}, // west
-                            { 0,-1}, // south
-                            { 1, 1}, // ne
-                            {-1, 1}, // nw
-                            {-1,-1}, // sw
-                            { 1,-1}, // se
-                            };
-
-const S32 gDirMasks[8] = {
+constexpr S32 gDirAxes[8][2] = {
+                               { 1, 0}, // east
+                               { 0, 1}, // north
+                               {-1, 0}, // west
+                               { 0,-1}, // south
+                               { 1, 1}, // ne
+                               {-1, 1}, // nw
+                               {-1,-1}, // sw
+                               { 1,-1}, // se
+                               };
+
+constexpr S32 gDirMasks[8] = {
                             EAST_MASK,
                             NORTH_MASK,
                             WEST_MASK,
@@ -117,22 +117,22 @@ const S32 gDirMasks[8] = {
 //       | /       -6-      | /
 //       |/        /        |/
 //       +------------------+
-const U32 NO_SIDE       = 0;
-const U32 FRONT_SIDE    = 1;
-const U32 BACK_SIDE     = 2;
-const U32 LEFT_SIDE     = 3;
-const U32 RIGHT_SIDE    = 4;
-const U32 TOP_SIDE      = 5;
-const U32 BOTTOM_SIDE   = 6;
-
-const U8 LL_SOUND_FLAG_NONE =         0x0;
-const U8 LL_SOUND_FLAG_LOOP =         1<<0;
-const U8 LL_SOUND_FLAG_SYNC_MASTER =  1<<1;
-const U8 LL_SOUND_FLAG_SYNC_SLAVE =   1<<2;
-const U8 LL_SOUND_FLAG_SYNC_PENDING = 1<<3;
-const U8 LL_SOUND_FLAG_QUEUE =        1<<4;
-const U8 LL_SOUND_FLAG_STOP =         1<<5;
-const U8 LL_SOUND_FLAG_SYNC_MASK = LL_SOUND_FLAG_SYNC_MASTER | LL_SOUND_FLAG_SYNC_SLAVE | LL_SOUND_FLAG_SYNC_PENDING;
+constexpr U32 NO_SIDE       = 0;
+constexpr U32 FRONT_SIDE    = 1;
+constexpr U32 BACK_SIDE     = 2;
+constexpr U32 LEFT_SIDE     = 3;
+constexpr U32 RIGHT_SIDE    = 4;
+constexpr U32 TOP_SIDE      = 5;
+constexpr U32 BOTTOM_SIDE   = 6;
+
+constexpr U8 LL_SOUND_FLAG_NONE =         0x0;
+constexpr U8 LL_SOUND_FLAG_LOOP =         1<<0;
+constexpr U8 LL_SOUND_FLAG_SYNC_MASTER =  1<<1;
+constexpr U8 LL_SOUND_FLAG_SYNC_SLAVE =   1<<2;
+constexpr U8 LL_SOUND_FLAG_SYNC_PENDING = 1<<3;
+constexpr U8 LL_SOUND_FLAG_QUEUE =        1<<4;
+constexpr U8 LL_SOUND_FLAG_STOP =         1<<5;
+constexpr U8 LL_SOUND_FLAG_SYNC_MASK = LL_SOUND_FLAG_SYNC_MASTER | LL_SOUND_FLAG_SYNC_SLAVE | LL_SOUND_FLAG_SYNC_PENDING;
 
 //
 // *NOTE: These values may be used as hard-coded numbers in scanf() variants.
@@ -141,17 +141,17 @@ const U8 LL_SOUND_FLAG_SYNC_MASK = LL_SOUND_FLAG_SYNC_MASTER | LL_SOUND_FLAG_SYN
 // DO NOT CHANGE.
 // --------------
 //
-const U32   LL_MAX_PATH     = 1024;     // buffer size of maximum path + filename string length
+constexpr U32   LL_MAX_PATH     = 1024;     // buffer size of maximum path + filename string length
 
 // For strings we send in messages
-const U32   STD_STRING_BUF_SIZE = 255;  // Buffer size
-const U32   STD_STRING_STR_LEN  = 254;  // Length of the string (not including \0)
+constexpr U32   STD_STRING_BUF_SIZE = 255;  // Buffer size
+constexpr U32   STD_STRING_STR_LEN  = 254;  // Length of the string (not including \0)
 
 // *NOTE: This value is used as hard-coded numbers in scanf() variants.
 // DO NOT CHANGE.
-const U32   MAX_STRING          = STD_STRING_BUF_SIZE;  // Buffer size
+constexpr U32   MAX_STRING          = STD_STRING_BUF_SIZE;  // Buffer size
 
-const U32   MAXADDRSTR      = 17;       // 123.567.901.345 = 15 chars + \0 + 1 for good luck
+constexpr U32   MAXADDRSTR      = 17;       // 123.567.901.345 = 15 chars + \0 + 1 for good luck
 
 // C++ is our friend. . . use template functions to make life easier!
 
diff --git a/indra/llcommon/llevents.cpp b/indra/llcommon/llevents.cpp
index 8006f9d059..3c6743eac9 100644
--- a/indra/llcommon/llevents.cpp
+++ b/indra/llcommon/llevents.cpp
@@ -3,25 +3,25 @@
  * @author Nat Goodspeed
  * @date   2008-09-12
  * @brief  Implementation for llevents.
- * 
+ *
  * $LicenseInfo:firstyear=2008&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, 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
  * $/LicenseInfo$
  */
@@ -423,8 +423,8 @@ LLBoundListener LLEventPump::listen_impl(const std::string& name, const LLEventL
 
     float nodePosition = 1.0;
 
-    // if the supplied name is empty we are not interested in the ordering mechanism 
-    // and can bypass attempting to find the optimal location to insert the new 
+    // if the supplied name is empty we are not interested in the ordering mechanism
+    // and can bypass attempting to find the optimal location to insert the new
     // listener.  We'll just tack it on to the end.
     if (!name.empty()) // should be the same as testing against ANONYMOUS
     {
@@ -569,12 +569,12 @@ LLBoundListener LLEventPump::listen_impl(const std::string& name, const LLEventL
     // Now that newNode has a value that places it appropriately in mSignal,
     // connect it.
     LLBoundListener bound = mSignal->connect(nodePosition, listener);
-    
+
     if (!name.empty())
     {   // note that we are not tracking anonymous listeners here either.
-        // This means that it is the caller's responsibility to either assign 
-        // to a TempBoundListerer (scoped_connection) or manually disconnect 
-        // when done. 
+        // This means that it is the caller's responsibility to either assign
+        // to a TempBoundListerer (scoped_connection) or manually disconnect
+        // when done.
         mConnections[name] = bound;
     }
     return bound;
@@ -641,9 +641,9 @@ bool LLEventMailDrop::post(const LLSD& event)
 {
     // forward the call to our base class
     bool posted = LLEventStream::post(event);
-    
+
     if (!posted)
-    {   // if the event was not handled we will save it for later so that it can 
+    {   // if the event was not handled we will save it for later so that it can
         // be posted to any future listeners when they attach.
         mEventHistory.push_back(event);
     }
diff --git a/indra/llcommon/llfasttimer.h b/indra/llcommon/llfasttimer.h
index 17ad37b031..09fcf8a1af 100644
--- a/indra/llcommon/llfasttimer.h
+++ b/indra/llcommon/llfasttimer.h
@@ -215,7 +215,7 @@ private:
 
 private:
     U64                     mStartTime;
-    BlockTimerStackRecord   mParentTimerData;
+    BlockTimerStackRecord   mParentTimerData{};
 
 public:
     // statics
diff --git a/indra/llcommon/llfile.cpp b/indra/llcommon/llfile.cpp
index 1877dd54ed..ddf239f306 100644
--- a/indra/llcommon/llfile.cpp
+++ b/indra/llcommon/llfile.cpp
@@ -27,6 +27,12 @@
  * $/LicenseInfo$
  */
 
+#include "linden_common.h"
+#include "llfile.h"
+#include "llstring.h"
+#include "llerror.h"
+#include "stringize.h"
+
 #if LL_WINDOWS
 #include "llwin32headerslean.h"
 #include <stdlib.h>                 // Windows errno
@@ -35,12 +41,6 @@
 #include <errno.h>
 #endif
 
-#include "linden_common.h"
-#include "llfile.h"
-#include "llstring.h"
-#include "llerror.h"
-#include "stringize.h"
-
 using namespace std;
 
 static std::string empty;
@@ -345,7 +345,7 @@ const char *LLFile::tmpdir()
         sep = '\\';
 
         std::vector<wchar_t> utf16path(MAX_PATH + 1);
-        GetTempPathW(utf16path.size(), &utf16path[0]);
+        GetTempPathW(static_cast<DWORD>(utf16path.size()), &utf16path[0]);
         utf8path = ll_convert_wide_to_string(&utf16path[0]);
 #else
         sep = '/';
diff --git a/indra/llcommon/llfile.h b/indra/llcommon/llfile.h
index 08a008c19a..2564671b13 100644
--- a/indra/llcommon/llfile.h
+++ b/indra/llcommon/llfile.h
@@ -97,7 +97,7 @@ public:
     // no copy
     LLUniqueFile(const LLUniqueFile&) = delete;
     // move construction
-    LLUniqueFile(LLUniqueFile&& other)
+    LLUniqueFile(LLUniqueFile&& other) noexcept
     {
         mFileHandle = other.mFileHandle;
         other.mFileHandle = nullptr;
@@ -118,7 +118,7 @@ public:
     // copy assignment deleted
     LLUniqueFile& operator=(const LLUniqueFile&) = delete;
     // move assignment
-    LLUniqueFile& operator=(LLUniqueFile&& other)
+    LLUniqueFile& operator=(LLUniqueFile&& other) noexcept
     {
         close();
         std::swap(mFileHandle, other.mFileHandle);
diff --git a/indra/llcommon/llfindlocale.cpp b/indra/llcommon/llfindlocale.cpp
index e39812bfc4..ac52f90c9f 100644
--- a/indra/llcommon/llfindlocale.cpp
+++ b/indra/llcommon/llfindlocale.cpp
@@ -157,14 +157,22 @@ canonise_fl(FL_Locale *l) {
   if (l->lang && 0 == strcmp(l->lang, "en")) {
     if (l->country && 0 == strcmp(l->country, "UK")) {
       free((void*)l->country);
+#ifdef LL_WINDOWS
+      l->country = _strdup("GB");
+#else
       l->country = strdup("GB");
+#endif
     }
   }
   /* ja_JA -> ja_JP */
   if (l->lang && 0 == strcmp(l->lang, "ja")) {
     if (l->country && 0 == strcmp(l->country, "JA")) {
       free((void*)l->country);
+#ifdef LL_WINDOWS
+      l->country = _strdup("JP");
+#else
       l->country = strdup("JP");
+#endif
     }
   }
 }
diff --git a/indra/llcommon/llindexedvector.h b/indra/llcommon/llindexedvector.h
index de3ae0dcc4..0b2e9c76ca 100644
--- a/indra/llcommon/llindexedvector.h
+++ b/indra/llcommon/llindexedvector.h
@@ -47,7 +47,7 @@ public:
     typedef typename std::vector<Type>::size_type size_type;
 protected:
     std::vector<Type> mVector;
-    std::map<Key, U32> mIndexMap;
+    std::map<Key, size_t> mIndexMap;
 
 public:
     LLIndexedVector() { mVector.reserve(BlockSize); }
@@ -68,10 +68,10 @@ public:
 
     Type& operator[](const Key& k)
     {
-        typename std::map<Key, U32>::const_iterator iter = mIndexMap.find(k);
+        typename std::map<Key, size_t>::const_iterator iter = mIndexMap.find(k);
         if (iter == mIndexMap.end())
         {
-            U32 n = mVector.size();
+            auto n = mVector.size();
             mIndexMap[k] = n;
             mVector.push_back(Type());
             llassert(mVector.size() == mIndexMap.size());
@@ -85,7 +85,7 @@ public:
 
     const_iterator find(const Key& k) const
     {
-        typename std::map<Key, U32>::const_iterator iter = mIndexMap.find(k);
+        typename std::map<Key, size_t>::const_iterator iter = mIndexMap.find(k);
         if(iter == mIndexMap.end())
         {
             return mVector.end();
diff --git a/indra/llcommon/llleap.cpp b/indra/llcommon/llleap.cpp
index e93ba83434..662a2511cd 100644
--- a/indra/llcommon/llleap.cpp
+++ b/indra/llcommon/llleap.cpp
@@ -233,7 +233,7 @@ public:
 
         LL_DEBUGS("EventHost") << "Sending: "
                                << static_cast<U64>(buffer.tellp()) << ':';
-        std::string::size_type truncate(80);
+        llssize truncate(80);
         if (buffer.tellp() <= truncate)
         {
             LL_CONT << buffer.str();
diff --git a/indra/llcommon/llmainthreadtask.h b/indra/llcommon/llmainthreadtask.h
index 5fae0212c4..cec95b2356 100644
--- a/indra/llcommon/llmainthreadtask.h
+++ b/indra/llcommon/llmainthreadtask.h
@@ -4,7 +4,7 @@
  * @date   2019-12-04
  * @brief  LLMainThreadTask dispatches work to the main thread. When invoked on
  *         the main thread, it performs the work inline.
- * 
+ *
  * $LicenseInfo:firstyear=2019&license=viewerlgpl$
  * Copyright (c) 2019, Linden Research, Inc.
  * $/LicenseInfo$
diff --git a/indra/llcommon/llpreprocessor.h b/indra/llcommon/llpreprocessor.h
index a54408a852..0248e8f8b9 100644
--- a/indra/llcommon/llpreprocessor.h
+++ b/indra/llcommon/llpreprocessor.h
@@ -120,44 +120,20 @@
 #endif  //  LL_WINDOWS
 
 
-// Deal with VC6 problems
+// Deal with VC++ problems
 #if LL_MSVC
-#pragma warning( 3       : 4701 )   // "local variable used without being initialized"  Treat this as level 3, not level 4.
-#pragma warning( 3       : 4702 )   // "unreachable code"  Treat this as level 3, not level 4.
-#pragma warning( 3       : 4189 )   // "local variable initialized but not referenced"  Treat this as level 3, not level 4.
-//#pragma warning( 3    : 4018 )    // "signed/unsigned mismatch"  Treat this as level 3, not level 4.
-#pragma warning( 3      :  4263 )   // 'function' : member function does not override any base class virtual member function
-#pragma warning( 3      :  4264 )   // "'virtual_function' : no override available for virtual member function from base 'class'; function is hidden"
-#pragma warning( 3       : 4265 )   // "class has virtual functions, but destructor is not virtual"
-#pragma warning( 3      :  4266 )   // 'function' : no override available for virtual member function from base 'type'; function is hidden
-#pragma warning (disable : 4180)    // qualifier applied to function type has no meaning; ignored
-//#pragma warning( disable : 4284 ) // silly MS warning deep inside their <map> include file
-
-#if ADDRESS_SIZE == 64
-// That one is all over the place for x64 builds.
-#pragma warning( disable : 4267 )   // 'var' : conversion from 'size_t' to 'type', possible loss of data)
+#ifndef _CRT_SECURE_NO_WARNINGS
+#define _CRT_SECURE_NO_WARNINGS // disable warnings for methods considered unsafe
+#endif
+#ifndef _WINSOCK_DEPRECATED_NO_WARNINGS
+#define _WINSOCK_DEPRECATED_NO_WARNINGS // disable deprecated WinSock API warnings
 #endif
-
-#pragma warning( disable : 4503 )   // 'decorated name length exceeded, name was truncated'. Does not seem to affect compilation.
-#pragma warning( disable : 4800 )   // 'BOOL' : forcing value to bool 'true' or 'false' (performance warning)
-#pragma warning( disable : 4996 )   // warning: deprecated
-
-// Linker optimization with "extern template" generates these warnings
-#pragma warning( disable : 4231 )   // nonstandard extension used : 'extern' before template explicit instantiation
-#pragma warning( disable : 4506 )   // no definition for inline function
 
 // level 4 warnings that we need to disable:
-#pragma warning (disable : 4100) // unreferenced formal parameter
-#pragma warning (disable : 4127) // conditional expression is constant (e.g. while(1) )
 #pragma warning (disable : 4244) // possible loss of data on conversions
 #pragma warning (disable : 4396) // the inline specifier cannot be used when a friend declaration refers to a specialization of a function template
-#pragma warning (disable : 4512) // assignment operator could not be generated
-#pragma warning (disable : 4706) // assignment within conditional (even if((x = y)) )
-
 #pragma warning (disable : 4251) // member needs to have dll-interface to be used by clients of class
 #pragma warning (disable : 4275) // non dll-interface class used as base for dll-interface class
-#pragma warning (disable : 4018) // '<' : signed/unsigned mismatch
-
 #endif  //  LL_MSVC
 
 #if LL_WINDOWS
diff --git a/indra/llcommon/llqueuedthread.cpp b/indra/llcommon/llqueuedthread.cpp
index 39e8113587..7d77f6f6a9 100644
--- a/indra/llcommon/llqueuedthread.cpp
+++ b/indra/llcommon/llqueuedthread.cpp
@@ -210,7 +210,7 @@ void LLQueuedThread::waitOnPending()
 // MAIN thread
 void LLQueuedThread::printQueueStats()
 {
-    U32 size = mRequestQueue.size();
+    auto size = mRequestQueue.size();
     if (size > 0)
     {
         LL_INFOS() << llformat("Pending Requests:%d ", mRequestQueue.size()) << LL_ENDL;
diff --git a/indra/llcommon/llsdjson.cpp b/indra/llcommon/llsdjson.cpp
index 2fe24693dd..e95d2e6c1c 100644
--- a/indra/llcommon/llsdjson.cpp
+++ b/indra/llcommon/llsdjson.cpp
@@ -1,25 +1,25 @@
-/** 
+/**
  * @file llsdjson.cpp
  * @brief LLSD flexible data system
  *
  * $LicenseInfo:firstyear=2015&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2015, 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
  * $/LicenseInfo$
  */
diff --git a/indra/llcommon/llsdjson.h b/indra/llcommon/llsdjson.h
index 7173e26046..415bbf4821 100644
--- a/indra/llcommon/llsdjson.h
+++ b/indra/llcommon/llsdjson.h
@@ -1,25 +1,25 @@
-/** 
+/**
  * @file llsdjson.cpp
  * @brief LLSD flexible data system
  *
  * $LicenseInfo:firstyear=2015&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2015, 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
  * $/LicenseInfo$
  */
@@ -36,10 +36,10 @@
 #include "llsd.h"
 #include <boost/json.hpp>
 
-/// Convert a parsed JSON structure into LLSD maintaining member names and 
+/// Convert a parsed JSON structure into LLSD maintaining member names and
 /// array indexes.
 /// JSON/JavaScript types are converted as follows:
-/// 
+///
 /// JSON Type     | LLSD Type
 /// --------------+--------------
 ///  null         |  undefined
@@ -50,14 +50,14 @@
 ///  boolean      |  LLSD::Boolean
 ///  array        |  LLSD::Array
 ///  object       |  LLSD::Map
-///  
+///
 /// For maps and arrays child entries will be converted and added to the structure.
 /// Order is preserved for an array but not for objects.
 LLSD LlsdFromJson(const boost::json::value &val);
 
-/// Convert an LLSD object into Parsed JSON object maintaining member names and 
+/// Convert an LLSD object into Parsed JSON object maintaining member names and
 /// array indexs.
-/// 
+///
 /// Types are converted as follows:
 /// LLSD Type     |  JSON Type
 /// --------------+----------------
@@ -71,7 +71,7 @@ LLSD LlsdFromJson(const boost::json::value &val);
 /// TypeUUID      | string
 /// TypeMap       | object
 /// TypeArray     | array
-/// TypeBinary    | unsupported 
+/// TypeBinary    | unsupported
 boost::json::value LlsdToJson(const LLSD &val);
 
 #endif // LL_LLSDJSON_H
diff --git a/indra/llcommon/llsdserialize.cpp b/indra/llcommon/llsdserialize.cpp
index 92d9392477..15002580c9 100644
--- a/indra/llcommon/llsdserialize.cpp
+++ b/indra/llcommon/llsdserialize.cpp
@@ -1546,7 +1546,7 @@ S32 LLSDBinaryFormatter::format_impl(const LLSD& data, std::ostream& ostr,
     case LLSD::TypeMap:
     {
         ostr.put('{');
-        U32 size_nbo = htonl(data.size());
+        U32 size_nbo = htonl(static_cast<u_long>(data.size()));
         ostr.write((const char*)(&size_nbo), sizeof(U32));
         LLSD::map_const_iterator iter = data.beginMap();
         LLSD::map_const_iterator end = data.endMap();
@@ -1563,7 +1563,7 @@ S32 LLSDBinaryFormatter::format_impl(const LLSD& data, std::ostream& ostr,
     case LLSD::TypeArray:
     {
         ostr.put('[');
-        U32 size_nbo = htonl(data.size());
+        U32 size_nbo = htonl(static_cast<u_long>(data.size()));
         ostr.write((const char*)(&size_nbo), sizeof(U32));
         LLSD::array_const_iterator iter = data.beginArray();
         LLSD::array_const_iterator end = data.endArray();
@@ -1630,7 +1630,7 @@ S32 LLSDBinaryFormatter::format_impl(const LLSD& data, std::ostream& ostr,
     {
         ostr.put('b');
         const std::vector<U8>& buffer = data.asBinary();
-        U32 size_nbo = htonl(buffer.size());
+        U32 size_nbo = htonl(static_cast<u_long>(buffer.size()));
         ostr.write((const char*)(&size_nbo), sizeof(U32));
         if(buffer.size()) ostr.write((const char*)&buffer[0], buffer.size());
         break;
@@ -1648,7 +1648,7 @@ void LLSDBinaryFormatter::formatString(
     const std::string& string,
     std::ostream& ostr) const
 {
-    U32 size_nbo = htonl(string.size());
+    U32 size_nbo = htonl(static_cast<u_long>(string.size()));
     ostr.write((const char*)(&size_nbo), sizeof(U32));
     ostr.write(string.c_str(), string.size());
 }
diff --git a/indra/llcommon/llsingleton.h b/indra/llcommon/llsingleton.h
index 61f82a4c03..7c6be25309 100644
--- a/indra/llcommon/llsingleton.h
+++ b/indra/llcommon/llsingleton.h
@@ -1,24 +1,24 @@
-/** 
+/**
  * @file llsingleton.h
  *
  * $LicenseInfo:firstyear=2002&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, 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
  * $/LicenseInfo$
  */
@@ -36,6 +36,10 @@
 #include "llthread.h"               // on_main_thread()
 #include "llmainthreadtask.h"
 
+#ifdef LL_WINDOWS
+#pragma warning( disable : 4506 )   // no definition for inline function
+#endif
+
 class LLSingletonBase: private boost::noncopyable
 {
 public:
@@ -528,6 +532,7 @@ public:
                          classname<DERIVED_TYPE>(),
                          " -- creating new instance"});
                 // fall through
+                [[fallthrough]];
             case UNINITIALIZED:
             case QUEUED:
                 // QUEUED means some secondary thread has already requested an
@@ -826,7 +831,7 @@ private:                                                                \
 
 // Relatively unsafe singleton implementation that is much faster
 // and simpler than LLSingleton, but has no dependency tracking
-// or inherent thread safety and requires manual invocation of 
+// or inherent thread safety and requires manual invocation of
 // createInstance before first use.
 template<class T>
 class LLSimpleton
diff --git a/indra/llcommon/llstl.h b/indra/llcommon/llstl.h
index 67b4c141af..1b52d94258 100644
--- a/indra/llcommon/llstl.h
+++ b/indra/llcommon/llstl.h
@@ -326,7 +326,7 @@ inline bool vector_replace_with_last(std::vector<T>& invec, const T& val)
 template <typename T>
 inline T* vector_append(std::vector<T>& invec, S32 N)
 {
-    U32 sz = invec.size();
+    auto sz = invec.size();
     invec.resize(sz+N);
     return &(invec[sz]);
 }
diff --git a/indra/llcommon/llstreamqueue.h b/indra/llcommon/llstreamqueue.h
index a09bf4cb4b..01689457dd 100644
--- a/indra/llcommon/llstreamqueue.h
+++ b/indra/llcommon/llstreamqueue.h
@@ -216,7 +216,7 @@ std::streamsize LLGenericStreamQueue<Ch>::skip(std::streamsize n)
 {
     typename BufferList::iterator bli(mBuffer.begin()), blend(mBuffer.end());
     std::streamsize toskip(n), skipped(0);
-    while (bli != blend && toskip >= bli->length())
+    while (bli != blend && (size_t)toskip >= bli->length())
     {
         std::streamsize chunk(bli->length());
         typename BufferList::iterator zap(bli++);
diff --git a/indra/llcommon/llstring.cpp b/indra/llcommon/llstring.cpp
index 5df0f8702d..514d73b24b 100644
--- a/indra/llcommon/llstring.cpp
+++ b/indra/llcommon/llstring.cpp
@@ -809,7 +809,7 @@ std::string ll_convert_wide_to_string(const wchar_t* in, size_t len_in, unsigned
             code_page,
             0,
             in,
-            len_in,
+            static_cast<int>(len_in),
             NULL,
             0,
             0,
@@ -824,7 +824,7 @@ std::string ll_convert_wide_to_string(const wchar_t* in, size_t len_in, unsigned
                 code_page,
                 0,
                 in,
-                len_in,
+                static_cast<int>(len_in),
                 pout,
                 len_out,
                 0,
@@ -851,8 +851,8 @@ std::wstring ll_convert_string_to_wide(const char* in, size_t len, unsigned int
     std::vector<wchar_t> w_out(len + 1);
 
     memset(&w_out[0], 0, w_out.size());
-    int real_output_str_len = MultiByteToWideChar(code_page, 0, in, len,
-                                                  &w_out[0], w_out.size() - 1);
+    int real_output_str_len = MultiByteToWideChar(code_page, 0, in, static_cast<int>(len),
+                                                  &w_out[0], static_cast<int>(w_out.size() - 1));
 
     //looks like MultiByteToWideChar didn't add null terminator to converted string, see EXT-4858.
     w_out[real_output_str_len] = 0;
@@ -943,7 +943,7 @@ std::optional<std::wstring> llstring_getoptenv(const std::string& key)
     auto wkey = ll_convert_string_to_wide(key);
     // Take a wild guess as to how big the buffer should be.
     std::vector<wchar_t> buffer(1024);
-    auto n = GetEnvironmentVariableW(wkey.c_str(), &buffer[0], buffer.size());
+    auto n = GetEnvironmentVariableW(wkey.c_str(), &buffer[0], static_cast<DWORD>(buffer.size()));
     // If our initial guess was too short, n will indicate the size (in
     // wchar_t's) that buffer should have been, including the terminating nul.
     if (n > (buffer.size() - 1))
@@ -951,7 +951,7 @@ std::optional<std::wstring> llstring_getoptenv(const std::string& key)
         // make it big enough
         buffer.resize(n);
         // and try again
-        n = GetEnvironmentVariableW(wkey.c_str(), &buffer[0], buffer.size());
+        n = GetEnvironmentVariableW(wkey.c_str(), &buffer[0], static_cast<DWORD>(buffer.size()));
     }
     // did that (ultimately) succeed?
     if (n)
diff --git a/indra/llcommon/llthread.h b/indra/llcommon/llthread.h
index cf2ae00cd7..4194e0014d 100644
--- a/indra/llcommon/llthread.h
+++ b/indra/llcommon/llthread.h
@@ -1,25 +1,25 @@
-/** 
+/**
  * @file llthread.h
  * @brief Base classes for thread, mutex and condition handling.
  *
  * $LicenseInfo:firstyear=2004&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010-2013, 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
  * $/LicenseInfo$
  */
@@ -55,10 +55,10 @@ public:
     LLThread(const std::string& name, apr_pool_t *poolp = NULL);
     virtual ~LLThread(); // Warning!  You almost NEVER want to destroy a thread unless it's in the STOPPED state.
     virtual void shutdown(); // stops the thread
-    
+
     bool isQuitting() const { return (QUITTING == mStatus); }
     bool isStopped() const { return (STOPPED == mStatus) || (CRASHED == mStatus); }
-    bool isCrashed() const { return (CRASHED == mStatus); } 
+    bool isCrashed() const { return (CRASHED == mStatus); }
 
     static id_t currentID(); // Return ID of current thread
     static void yield(); // Static because it can be called by the main thread, which doesn't have an LLThread data structure.
@@ -90,11 +90,11 @@ public:
     // internal state used by LLMutex.  You must call this once early
     // in the running thread to prevent collisions with the main thread.
     static void registerThreadID();
-    
+
 private:
     bool                mPaused;
     std::thread::native_handle_type mNativeHandle; // for termination in case of issues
-    
+
     // static function passed to APR thread creation routine
     void threadRun();
 
@@ -111,21 +111,21 @@ protected:
     //a local apr_pool for APRFile operations in this thread. If it exists, LLAPRFile::sAPRFilePoolp should not be used.
     //Note: this pool is used by APRFile ONLY, do NOT use it for any other purposes.
     //      otherwise it will cause severe memory leaking!!! --bao
-    LLVolatileAPRPool  *mLocalAPRFilePoolp ; 
+    LLVolatileAPRPool  *mLocalAPRFilePoolp ;
 
     void setQuitting();
-    
+
     // virtual function overridden by subclass -- this will be called when the thread runs
-    virtual void run(void) = 0; 
-    
+    virtual void run(void) = 0;
+
     // virtual predicate function -- returns true if the thread should wake up, false if it should sleep.
     virtual bool runCondition(void);
 
     // Lock/Unlock Run Condition -- use around modification of any variable used in runCondition()
     void lockData();
     void unlockData();
-    
-    // This is the predicate that decides whether the thread should sleep.  
+
+    // This is the predicate that decides whether the thread should sleep.
     // It should only be called with mDataLock locked, since the virtual runCondition() function may need to access
     // data structures that are thread-unsafe.
     bool shouldSleep(void) { return (mStatus == RUNNING) && (isPaused() || (!runCondition())); }
diff --git a/indra/llcommon/lltraceaccumulators.h b/indra/llcommon/lltraceaccumulators.h
index 692bbe5acf..ba7acf9547 100644
--- a/indra/llcommon/lltraceaccumulators.h
+++ b/indra/llcommon/lltraceaccumulators.h
@@ -522,9 +522,9 @@ namespace LLTrace
 
     struct BlockTimerStackRecord
     {
-        class BlockTimer*   mActiveTimer;
-        class BlockTimerStatHandle* mTimeBlock;
-        U64                 mChildTime;
+        class BlockTimer*   mActiveTimer{ nullptr };
+        class BlockTimerStatHandle* mTimeBlock{ nullptr };
+        U64                 mChildTime{ 0 };
     };
 
     struct AccumulatorBufferGroup : public LLRefCount
diff --git a/indra/llcommon/lluuid.h b/indra/llcommon/lluuid.h
index b178868591..bd4edc7993 100644
--- a/indra/llcommon/lluuid.h
+++ b/indra/llcommon/lluuid.h
@@ -82,8 +82,6 @@ public:
     // to integers, among other things.  Use isNull() or notNull().
     //      operator bool() const;
 
-    // JC: These must return real bool's (not BOOLs) or else use of the STL
-    // will generate bool-to-int performance warnings.
     bool    operator==(const LLUUID &rhs) const;
     bool    operator!=(const LLUUID &rhs) const;
     bool    operator<(const LLUUID &rhs) const;
diff --git a/indra/llcommon/tests/commonmisc_test.cpp b/indra/llcommon/tests/commonmisc_test.cpp
index 3deb864c0c..0057a1f639 100644
--- a/indra/llcommon/tests/commonmisc_test.cpp
+++ b/indra/llcommon/tests/commonmisc_test.cpp
@@ -67,7 +67,7 @@ namespace tut
         std::ostringstream resp;
         resp << "{'connect':true,  'position':[r128,r128,r128], 'look_at':[r0,r1,r0], 'agent_access':'M', 'region_x':i8192, 'region_y':i8192}";
         std::string str = resp.str();
-        LLMemoryStream mstr((U8*)str.c_str(), str.size());
+        LLMemoryStream mstr((U8*)str.c_str(), static_cast<S32>(str.size()));
         LLSD response;
         S32 count = LLSDSerialize::fromNotation(response, mstr, str.size());
         ensure("stream parsed", response.isDefined());
@@ -252,7 +252,7 @@ namespace tut
         resp << "{'label':'short binary test', 'singlebinary':b(1)\"A\", 'singlerawstring':s(1)\"A\", 'endoftest':'end' }";
         std::string str = resp.str();
         LLSD sd;
-        LLMemoryStream mstr((U8*)str.c_str(), str.size());
+        LLMemoryStream mstr((U8*)str.c_str(), static_cast<S32>(str.size()));
         S32 count = LLSDSerialize::fromNotation(sd, mstr, str.size());
         ensure_equals("parse count", count, 5);
         ensure("sd created", sd.isDefined());
@@ -456,7 +456,7 @@ namespace tut
     void mem_object::test<1>()
     {
         const char HELLO_WORLD[] = "hello world";
-        LLMemoryStream mem((U8*)&HELLO_WORLD[0], strlen(HELLO_WORLD));      /* Flawfinder: ignore */
+        LLMemoryStream mem((U8*)&HELLO_WORLD[0], static_cast<S32>(strlen(HELLO_WORLD)));      /* Flawfinder: ignore */
         std::string hello;
         std::string world;
         mem >> hello >> world;
diff --git a/indra/llcommon/tests/lleventdispatcher_test.cpp b/indra/llcommon/tests/lleventdispatcher_test.cpp
index a99acba848..44f772e322 100644
--- a/indra/llcommon/tests/lleventdispatcher_test.cpp
+++ b/indra/llcommon/tests/lleventdispatcher_test.cpp
@@ -491,7 +491,7 @@ namespace tut
             // Partial defaults arrays.
             for (LLSD::String a: ab)
             {
-                LLSD::Integer partition(std::min(partial_offset, dft_array_full[a].size()));
+                LLSD::Integer partition(static_cast<LLSD::Integer>(std::min(partial_offset, dft_array_full[a].size())));
                 dft_array_partial[a] =
                     llsd_copy_array(dft_array_full[a].beginArray() + partition,
                                     dft_array_full[a].endArray());
@@ -508,7 +508,7 @@ namespace tut
                 // (params, dft_array_full). Part of the point of using map-style
                 // defaults is to allow any subset of the target function's
                 // parameters to be optional, not just the rightmost.
-                for (LLSD::Integer ix = 0, ixend = params[a].size(); ix < ixend; ix += 2)
+                for (LLSD::Integer ix = 0, ixend = static_cast<LLSD::Integer>(params[a].size()); ix < ixend; ix += 2)
                 {
                     dft_map_partial[a][params[a][ix].asString()] = dft_array_full[a][ix];
                 }
@@ -696,7 +696,7 @@ namespace tut
         LLSD zipmap(const LLSD& keys, const LLSD& values)
         {
             LLSD map;
-            for (LLSD::Integer i = 0, iend = keys.size(); i < iend; ++i)
+            for (LLSD::Integer i = 0, iend = static_cast<LLSD::Integer>(keys.size()); i < iend; ++i)
             {
                 // Have to select asString() since you can index an LLSD
                 // object with either String or Integer.
@@ -955,7 +955,7 @@ namespace tut
             allreq[a] = zipmap(params[a], LLSD::emptyArray());
             // Same for leftreq, save that we use the subset of the params not
             // supplied by dft_array_partial[a].
-            LLSD::Integer partition(params[a].size() - dft_array_partial[a].size());
+            LLSD::Integer partition(static_cast<LLSD::Integer>(params[a].size() - dft_array_partial[a].size()));
             leftreq[a] = zipmap(llsd_copy_array(params[a].beginArray(),
                                                 params[a].beginArray() + partition),
                                 LLSD::emptyArray());
diff --git a/indra/llcommon/tests/llsdserialize_test.cpp b/indra/llcommon/tests/llsdserialize_test.cpp
index 56fdc51e82..fb2af1d2db 100644
--- a/indra/llcommon/tests/llsdserialize_test.cpp
+++ b/indra/llcommon/tests/llsdserialize_test.cpp
@@ -701,7 +701,7 @@ namespace tut
                 "<key>cam</key><real>1.23</real>"
             "</map></llsd>",
             v,
-            v.size() + 1);
+            static_cast<S32>(v.size()) + 1);
     }
 
     template<> template<>
@@ -721,7 +721,7 @@ namespace tut
                 "<key>cam</key><real>1.23</real>"
             "</map></llsd>",
             v,
-            v.size() + 1);
+            static_cast<S32>(v.size()) + 1);
 
         v.clear();
         v["amy"] = 23;
@@ -734,7 +734,7 @@ namespace tut
                 "<key>cam</key><real>1.23</real>"
             "</map></llsd>",
             v,
-            v.size() + 1);
+            static_cast<S32>(v.size()) + 1);
 
         v.clear();
         v["amy"] = 23;
@@ -751,7 +751,7 @@ namespace tut
                 "<key>cam</key><real>1.23</real>"
             "</map></llsd>",
             v,
-            v.size() + 1);
+            static_cast<S32>(v.size()) + 1);
 
         v.clear();
         v[0] = 23;
@@ -766,7 +766,7 @@ namespace tut
                 "<real>1.23</real>"
             "</array></llsd>",
             v,
-            v.size() + 1);
+            static_cast<S32>(v.size()) + 1);
 
         v.clear();
         v[0] = 23;
@@ -782,7 +782,7 @@ namespace tut
                 "<real>1.23</real>"
             "</array></llsd>",
             v,
-            v.size() + 1);
+            static_cast<S32>(v.size()) + 1);
     }
 
     template<> template<>
@@ -1405,13 +1405,13 @@ namespace tut
         uint32_t size = htonl(1);
         memcpy(&vec[1], &size, sizeof(uint32_t));
         vec.push_back('k');
-        int key_size_loc = vec.size();
+        auto key_size_loc = vec.size();
         size = htonl(1); // 1 too short
         vec.resize(vec.size() + 4);
         memcpy(&vec[key_size_loc], &size, sizeof(uint32_t));
         vec.push_back('a'); vec.push_back('m'); vec.push_back('y');
         vec.push_back('i');
-        int integer_loc = vec.size();
+        auto integer_loc = vec.size();
         vec.resize(vec.size() + 4);
         uint32_t val_int = htonl(23);
         memcpy(&vec[integer_loc], &val_int, sizeof(uint32_t));
@@ -1473,7 +1473,7 @@ namespace tut
         memcpy(&vec[1], &size, sizeof(uint32_t));
         vec.push_back('"'); vec.push_back('a'); vec.push_back('m');
         vec.push_back('y'); vec.push_back('"'); vec.push_back('i');
-        int integer_loc = vec.size();
+        auto integer_loc = vec.size();
         vec.resize(vec.size() + 4);
         uint32_t val_int = htonl(23);
         memcpy(&vec[integer_loc], &val_int, sizeof(uint32_t));
diff --git a/indra/llcommon/threadpool.cpp b/indra/llcommon/threadpool.cpp
index dbcfb775da..451e60c083 100644
--- a/indra/llcommon/threadpool.cpp
+++ b/indra/llcommon/threadpool.cpp
@@ -3,7 +3,7 @@
  * @author Nat Goodspeed
  * @date   2021-10-21
  * @brief  Implementation for threadpool.
- * 
+ *
  * $LicenseInfo:firstyear=2021&license=viewerlgpl$
  * Copyright (c) 2021, Linden Research, Inc.
  * $/LicenseInfo$