Update -redo option such that it removes CMakeCache.txt and CMakeFiles/

In the case of re-doing, `configure` and `configure.bat` pass an extra
parameter to the `QtProcessConfigureArgs.cmake`. As a result, CMake
removes CMakeCache.txt and CMakeFiles/ before the reconfiguration. If
the user is using CMake 3.24 or newer, this is achieved by passing
the `--fresh` option to CMake call. In older CMake(s), CMakeCache.txt
and CMakeFiles/ found in CMAKE_BINARY_DIR will be removed using a
file(REMOVE_RECURSIVE call.

[ChangeLog] The -redo option now additionally removes existing
CMakeCache.txt file, and CMakeFiles/ directory, and recreates them from
scratch.

Task-number: QTBUG-108287
Change-Id: I11a5c8f9df1247d11eb7097552e6764463583346
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

cmake/QtBuildInformation.cmake

@@ -93,7 +93,13 @@ function(qt_print_build_instructions)
         "\nTo configure and build other Qt modules, you can use the following convenience script:
         ${local_install_prefix}/${INSTALL_BINDIR}/${configure_module_command}")
     list(APPEND msg "\nIf reconfiguration fails for some reason, try removing 'CMakeCache.txt' \
-from the build directory \n")
+from the build directory")
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.24")
+        list(APPEND msg "Alternatively, you can add the --fresh flag to your CMake flags.\n")
+    else()
+        list(APPEND msg "\n")
+    endif()
+
     list(JOIN msg "\n" msg)
 
     if(NOT QT_INTERNAL_BUILD_INSTRUCTIONS_SHOWN)

cmake/QtBuildInternals/QtBuildInternalsConfig.cmake

@@ -531,6 +531,10 @@ macro(qt_build_repo_end)
         qt_internal_save_previously_found_packages()
     endif()
 
+    if(QT_INTERNAL_FRESH_REQUESTED)
+        set(QT_INTERNAL_FRESH_REQUESTED "FALSE" CACHE INTERNAL "")
+    endif()
+
     list(POP_BACK CMAKE_MESSAGE_CONTEXT)
 endmacro()
 

cmake/QtProcessConfigureArgs.cmake

@@ -144,6 +144,15 @@ while(NOT "${configure_args}" STREQUAL "")
     endif()
 endwhile()
 
+if(FRESH_REQUESTED)
+    push("-DQT_INTERNAL_FRESH_REQUESTED:BOOL=TRUE")
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.24")
+        push("--fresh")
+    else()
+        file(REMOVE_RECURSE "${CMAKE_BINARY_DIR}/CMakeCache.txt"
+                            "${CMAKE_BINARY_DIR}/CMakeFiles")
+    endif()
+endif()
 
 ####################################################################################################
 # Define functions/macros that are called in configure.cmake files

config_help.txt

@@ -44,7 +44,9 @@ options without auto-detection.
 Configure meta:
 
   -help, -h ............ Display this help screen
-  -redo ................ Re-configure with previously used options.
+  -redo ................ Re-configure with previously used options. In addition,
+                         redo removes CMakeCache.txt file and CMakeFiles/ directory
+                         and recreates them from scratch.
                          Additional options may be passed, but will not be
                          saved for later use by -redo.
 

configure

@@ -221,6 +221,8 @@ checkTopLevelBuild "$@"
 parseCommandline "$@"
 handleHelp
 determineOptFilePath "$@"
+
+fresh_requested_arg=
 optfilename=config.opt
 if [ -z "$optfile" ]; then   # only write optfile if not currently redoing
     optfilepath=${outpathPrefix}${optfilename}
@@ -231,6 +233,8 @@ if [ -z "$optfile" ]; then   # only write optfile if not currently redoing
         fi
         echo $arg >> "$optfilepath"
     done
+else
+    fresh_requested_arg=-DFRESH_REQUESTED=TRUE
 fi
 
 top_level_arg=
@@ -239,4 +243,4 @@ if [ -n "$CFG_TOPLEVEL" ]; then
     cd ..
 fi
 
-cmake "-DOPTFILE=$optfilename" $top_level_arg -P "$relpath/cmake/QtProcessConfigureArgs.cmake"
+cmake "-DOPTFILE=$optfilename" $top_level_arg $fresh_requested_arg -P "$relpath/cmake/QtProcessConfigureArgs.cmake"

configure.bat

@@ -78,12 +78,15 @@ goto doneargs
 cd "%TOPQTDIR%"
 
 rem Write config.opt if we're not currently -redo'ing
+set FRESH_REQUESTED_ARG=
 if "!rargs!" == "" (
     echo.%*>config.opt.in
     cmake -DIN_FILE=config.opt.in -DOUT_FILE=config.opt -DIGNORE_ARGS=-top-level -P "%QTSRC%\cmake\QtWriteArgsFile.cmake"
+) else if NOT "!rargs!" == "" (
+    set FRESH_REQUESTED_ARG=-DFRESH_REQUESTED=TRUE
 )
 
 rem Launch CMake-based configure
 set TOP_LEVEL_ARG=
 if %TOPLEVEL% == true set TOP_LEVEL_ARG=-DTOP_LEVEL=TRUE
-cmake -DOPTFILE=config.opt %TOP_LEVEL_ARG% -P "%QTSRC%\cmake\QtProcessConfigureArgs.cmake"
+cmake -DOPTFILE=config.opt %TOP_LEVEL_ARG% %FRESH_REQUESTED_ARG% -P "%QTSRC%\cmake\QtProcessConfigureArgs.cmake"