Infinite Loop in `script/cmake_generic.bat`

[SirNate0]

It is easy to reach an infinite loop when using the windows cmake scripts. For example, if you call script\cmake_vs2022.bat build -DURHO3D_HOME="C:\Path\To\U3D\Build", you will get such a loop, as cmake_generic.bat only recognizes -D options when they are followed by a space.

The loop

:loop
if not "%~1" == "" (
    if "%~1" == "-D" (
        if "%~2" == "MINGW" if "%~3" == "1" set "OPTS=-G "MinGW Makefiles""
        if "%~2" == "URHO3D_64BIT" if "%~3" == "1" set "arch=-A x64"
        if "%~2" == "URHO3D_64BIT" if "%~3" == "0" set "arch=-A Win32"
        set "BUILD_OPTS=%BUILD_OPTS% -D %~2=%~3"
        shift
        shift
        shift
    )
    if "%~1" == "-VS" (
        set "OPTS=-G "Visual Studio %~2" %arch% %TOOLSET%"
        shift
        shift
    )
    if "%~1" == "-G" (
        set "OPTS=%OPTS% -G %~2"
        shift
        shift
    )
    goto loop
)

should be changed to something like

:loop
if not "%~1" == "" (
    if "%~1" == "-D" (
        if "%~2" == "MINGW" if "%~3" == "1" set "OPTS=-G "MinGW Makefiles""
        if "%~2" == "URHO3D_64BIT" if "%~3" == "1" set "arch=-A x64"
        if "%~2" == "URHO3D_64BIT" if "%~3" == "0" set "arch=-A Win32"
        set "BUILD_OPTS=%BUILD_OPTS% -D %~2=%~3"
        shift
        shift
        shift
    )
    else if "%~1" == "-VS" (
        set "OPTS=-G "Visual Studio %~2" %arch% %TOOLSET%"
        shift
        shift
    )
    else if "%~1" == "-G" (
        set "OPTS=%OPTS% -G %~2"
        shift
        shift
    )
    else (
        set "OPTS=%OPTS% %~1"
        shift
    )
    goto loop
)

to prevent the possibility of endlessly looping on an unrecognized argument.

[BlueMagnificent]

Good observation. I ran into this somedays back while using Emcripten's emcmake which emits the CMAKE_TOOLCHAIN_FILE and CMAKE_CROSSCOMPILING_EMULATOR build options with no space after -D. I have a slightly different change I made to the loop section:

:loop
:: Cache the first argument so substring operation can be performed on it
set "ARG1=%~1"
if not "%~1" == "" (
    if "%~1" == "-D" (
        if "%~2" == "MINGW" if "%~3" == "1" set "OPTS=-G "MinGW Makefiles""
        if "%~2" == "URHO3D_64BIT" if "%~3" == "1" set "arch=-A x64"
        if "%~2" == "URHO3D_64BIT" if "%~3" == "0" set "arch=-A Win32"
        set "BUILD_OPTS=%BUILD_OPTS% -D %~2=%~3"
        shift
        shift
        shift
    ) else if "%ARG1:~0,2%" == "-D" (
        :: Handle case where there is no space after "-D" in the options
        set "BUILD_OPTS=%BUILD_OPTS% %~1=%~2"
        shift
        shift
    )
    if "%~1" == "-VS" (
        set "OPTS=-G "Visual Studio %~2" %arch% %TOOLSET%"
        shift
        shift
    )
    if "%~1" == "-G" (
        :: Add quote to MinGW Makefiles flag since Emscripten's `emcmake` emits them without quotes and this breaks CMake
        if "%~2" == "MinGW Makefiles" (
            set "OPTS=%OPTS% -G "%~2""
        ) else (
            set "OPTS=%OPTS% -G %~2"
        )
        shift
        shift
    )
    goto loop
)

Right after checking if "%~1" == "-D" an else part checks if %~1 starts with -D and if so appends %~1=%~2 to %BUILD_OPTS%.

I also noticed that emcmake emits the MinGW makefiles generator flag without quotes around MinGW Makefiles and this breaks CMake. This is also handled in the change I made.