Modifications to build C++ with Visual Studio 2026 and the v145 toolset.

cmake/CMakeLists.txt

@@ -178,26 +178,31 @@ if((BUILD_CONVERT OR BUILD_GEOMSERVER OR BUILD_IFCPYTHON) AND(NOT BUILD_IFCGEOM)
     set(BUILD_IFCGEOM ON)
 endif()
 
-find_program(CCACHE_FOUND ccache)
-if(CCACHE_FOUND)
-    message(STATUS "`ccache` is found, using it as a compiler launcher.")
-    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_FOUND}")
-    if(MSVC)
-        # By default Visual Studio generators will use /Zi which is not compatible
-        # with ccache, so tell Visual Studio to use /Z7 instead.
-        set(CMAKE_MSVC_DEBUG_INFORMATION_FORMAT "$<$<CONFIG:Debug,RelWithDebInfo>:Embedded>")
-        # Not needed for Ninja.
-        if(CMAKE_GENERATOR MATCHES "Visual Studio")
-            file(COPY_FILE
-                ${CCACHE_FOUND} ${CMAKE_BINARY_DIR}/cl.exe
-                ONLY_IF_DIFFERENT)
-            set(CMAKE_VS_GLOBALS
-                "CLToolExe=cl.exe"
-                "CLToolPath=${CMAKE_BINARY_DIR}"
-                "UseMultiToolTask=true"
-            )
+option(USE_CCACHE "Use ccache as a compiler launcher if it is found" ON)
+if(USE_CCACHE)
+    find_program(CCACHE_FOUND ccache)
+    if(CCACHE_FOUND)
+        message(STATUS "`ccache` is found, using it as a compiler launcher.")
+        set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_FOUND}")
+        if(MSVC)
+            # By default Visual Studio generators will use /Zi which is not compatible
+            # with ccache, so tell Visual Studio to use /Z7 instead.
+            set(CMAKE_MSVC_DEBUG_INFORMATION_FORMAT "$<$<CONFIG:Debug,RelWithDebInfo>:Embedded>")
+            # Not needed for Ninja.
+            if(CMAKE_GENERATOR MATCHES "Visual Studio")
+                file(COPY_FILE
+                    ${CCACHE_FOUND} ${CMAKE_BINARY_DIR}/cl.exe
+                    ONLY_IF_DIFFERENT)
+                set(CMAKE_VS_GLOBALS
+                    "CLToolExe=cl.exe"
+                    "CLToolPath=${CMAKE_BINARY_DIR}"
+                    "UseMultiToolTask=true"
+                )
+            endif()
         endif()
     endif()
+else()
+    message(STATUS "ccache usage disabled via USE_CCACHE=OFF")
 endif()
 
 if(MSVC AND MSVC_PARALLEL_BUILD)

win/build-deps.cmd

@@ -464,6 +464,10 @@ cd "%DEPENDENCY_DIR%"
 :: so disable it from the build altogether as we have no use for it
 findstr #add_subdirectory(COLLADAValidator) CMakeLists.txt>NUL
 IF NOT %ERRORLEVEL%==0 git apply --reject --whitespace=fix "%~dp0patches\OpenCOLLADA_CMakeLists.txt.patch" --ignore-whitespace
+:: std::tr1::unordered_map was a legacy MSVC compatibility shim kept around through VS2022's STL, but newer
+:: toolsets (e.g. VS2026/v145) no longer provide it, breaking the build with error C2039: 'tr1' is not a member of 'std'.
+findstr /C:"typedef std::unordered_map<MarkId, FilePosType > MarkIdToFilePos;" common\libBuffer\include\CommonFWriteBufferFlusher.h>NUL
+IF NOT %ERRORLEVEL%==0 git apply --reject --whitespace=fix "%~dp0patches\OpenCOLLADA_CommonFWriteBufferFlusher_tr1.patch" --ignore-whitespace
 :: NOTE OpenCOLLADA has been observed to have problems with switching between debug and release builds so
 :: uncomment to following line in order to delete the CMakeCache.txt always if experiencing problems.
 REM IF EXIST "%DEPENDENCY_DIR%\%BUILD_DIR%\CMakeCache.txt". del "%DEPENDENCY_DIR%\%BUILD_DIR%\CMakeCache.txt"
@@ -747,7 +751,12 @@ set QT6_MSVC_YEAR=%VS_VER%
 IF /I "%VS_TOOLSET%"=="v141" set QT6_MSVC_YEAR=2017
 IF /I "%VS_TOOLSET%"=="v142" set QT6_MSVC_YEAR=2019
 IF /I "%VS_TOOLSET%"=="v143" set QT6_MSVC_YEAR=2022
-IF /I "%VS_TOOLSET%"=="v145" set QT6_MSVC_YEAR=2026
+:: Qt has not published prebuilt msvc2026 binaries yet (aqt only lists win64_msvc2022_64 as of
+:: Qt 6.7-6.10). The v14x MSVC toolsets share a stable ABI/CRT, so fall back to the msvc2022
+:: binaries until Qt ships msvc2026 ones. Revisit once `aqt list-qt windows desktop --arch <ver>`
+:: shows a msvc2026 entry.
+IF /I "%VS_TOOLSET%"=="v145" set QT6_MSVC_YEAR=2022
+IF "%VS_VER%"=="2026" set QT6_MSVC_YEAR=2022
 
 set QT6_ARCH=
 set QT6_INSTALL_SUFFIX=

win/patches/OpenCOLLADA_CommonFWriteBufferFlusher_tr1.patch

@@ -0,0 +1,16 @@
+diff --git a/common/libBuffer/include/CommonFWriteBufferFlusher.h b/common/libBuffer/include/CommonFWriteBufferFlusher.h
+index c7af45b2..62b0f991 100644
+--- a/common/libBuffer/include/CommonFWriteBufferFlusher.h
++++ b/common/libBuffer/include/CommonFWriteBufferFlusher.h
+@@ -58,7 +58,11 @@ namespace Common
+ #else
+ 		typedef __int64 FilePosType;
+ #endif
++#if defined(__GNUC__) && !defined(_LIBCPP_VERSION) && !((defined(WIN64) || defined(_WIN64) || defined(__WIN64__)) || (defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || defined(__APPLE__)))
+ 	typedef std::tr1::unordered_map<MarkId, FilePosType > MarkIdToFilePos;
++#else
++	typedef std::unordered_map<MarkId, FilePosType > MarkIdToFilePos;
++#endif
+ 
+ 	public:
+ 		static const size_t DEFAUL_BUFFER_SIZE = 64*1024;

win/run-cmake.bat

@@ -20,10 +20,14 @@
 :: Example usage:
 ::   run-cmake.bat vs2022-x64
 ::   run-cmake.bat vs2022-x64 -DGLTF_SUPPORT=ON
+::   run-cmake.bat vs2022-x64 -DUSE_CCACHE=OFF
 ::
 :: Used environment variables:
 :: - `ADD_COMMIT_SHA` - if defined then `ADD_COMMIT_SHA` and `VERSION_OVERRIDE` cmake args will be set to `ON`.
 :: - `USE_NINJA` - if defined then the Ninja generator will be used instead of the Visual Studio.
+::
+:: -DUSE_CCACHE=OFF (also accepts 0/FALSE/NO/N) disables ccache: the bundled ccache
+:: install dir is kept out of CMAKE_PREFIX_PATH, and CMakeLists.txt skips detecting it.
 
 
 @if not defined ECHO_ON ( echo off )
@@ -81,6 +85,27 @@ if not (%1)==() (
     call set ARGUMENTS=%%ARGUMENTS:%1=%%
 )
 
+:: Honor -DUSE_CCACHE=OFF (also accepts 0/FALSE/NO/N, case-insensitive) by keeping
+:: the bundled ccache out of CMAKE_PREFIX_PATH so it can't be auto-detected below.
+set USE_CCACHE_VALUE=
+for %%A in (%*) do (
+    set "ARG=%%~A"
+    if not "!ARG:-DUSE_CCACHE=!"=="!ARG!" (
+        for /f "tokens=2 delims==" %%V in ("!ARG!") do set "USE_CCACHE_VALUE=%%V"
+    )
+)
+if defined USE_CCACHE_VALUE (
+    if /I "!USE_CCACHE_VALUE!"=="OFF"   set DISABLE_CCACHE=1
+    if /I "!USE_CCACHE_VALUE!"=="0"     set DISABLE_CCACHE=1
+    if /I "!USE_CCACHE_VALUE!"=="FALSE" set DISABLE_CCACHE=1
+    if /I "!USE_CCACHE_VALUE!"=="NO"    set DISABLE_CCACHE=1
+    if /I "!USE_CCACHE_VALUE!"=="N"     set DISABLE_CCACHE=1
+)
+if defined DISABLE_CCACHE (
+    echo USE_CCACHE=%USE_CCACHE_VALUE% passed, disabling ccache.
+    set "CCACHE_INSTALL_DIR="
+)
+
 pushd ..
 set CMAKE_INSTALL_PREFIX=%CD%\_installed-%GEN_SHORTHAND%
 popd