[Scons-users] MSVC is broken for x86 builds on x64 hosts

[Mats Wichmann]

On 3/28/19 8:04 AM, Michael Hartmann wrote:
> The code to support Visual Studio tries to construct a path to cl.exe
> form the host arch (amd64) and the target arch (x86):
> 
>  
> 
> vc.py:get_host_target()
> 
> vc.py:get_host_target() req_target_platform:x86
> 
> _check_cl_exists_in_vc_dir(): host platform amd64, target platform x86
> 
> _check_cl_exists_in_vc_dir(): checking for cl.exe at C:\Program Files
> (x86)\Microsoft Visual
> Studio\2017\WDExpress\VC\Tools\MSVC\14.14.26428\bin\Hostx64\x86\cl.exe
> 
> find_vc_pdir no compiler found 14.1
> 
> trying to find VC 14.0
> 
> find_vc_dir(): found VC in registry: C:\Program Files (x86)\Microsoft
> Visual Studio 14.0\VC\
> 
> found VC 14.0
> 
> vc.py:get_host_target()
> 
> vc.py:get_host_target() req_target_platform:x86
> 
> _check_cl_exists_in_vc_dir(): host platform amd64, target platform x86
> 
> _check_cl_exists_in_vc_dir(): checking for cl.exe at C:\Program Files
> (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64_x86\cl.exe
> 
> find_vc_pdir no compiler found 14.0
> 
> trying to find VC 14.0Exp
> 
> find_vc_dir(): no VC registry key
> 'Microsoft\\VCExpress\\14.0\\Setup\\VC\\ProductDir'
> 
> find_vc_pdir return None for ver 14.0Exp
> 
>  
> 
> The problem is: Visual Studio is always a x86 application. The compiler
> for a x86 target is not a cross compiler and is found in VC\bin, not
> VC\bin\amd64_x86.

Looking at a system here, both exist... under
"Microsoft Visual Studio 14.0/VC/bin" I see:

amd64/cl.exe
amd64_arm/cl.exe
amd64_x86/cl.exe
cl.exe
x86_amd64/cl.exe
x86_arm/cl.exe

(and of course VS 2017 has changed the equation completely)

nobody seems to be an expert here, so we're just guessing at the right
approaches...