[llvm] e8ee944 - [llvm][docs] Note Windows on Arm setting in Visual Studio guide (#147710)

[via llvm-commits]

Author: David Spickett
Date: 2025-10-14T15:37:05+01:00
New Revision: e8ee944a4f2e9f70c8b49452878c2ebe038a8da4

URL: https://github.com/llvm/llvm-project/commit/e8ee944a4f2e9f70c8b49452878c2ebe038a8da4
DIFF: https://github.com/llvm/llvm-project/commit/e8ee944a4f2e9f70c8b49452878c2ebe038a8da4.diff

LOG: [llvm][docs] Note Windows on Arm setting in Visual Studio guide (#147710)

As it very specifically wants ARM64 not what you'd guess which is arm64.

This guide talks about VS2019 that probably has little or no Windows on
Arm support, but I don't have the bandwidth to follow the whole thing
and update it right now.

I think this small change will be enough for most people who download
the latest Visual Studio on a Windows on Arm machine.


https://cmake.org/cmake/help/latest/variable/CMAKE_GENERATOR_TOOLSET.html

https://cmake.org/cmake/help/latest/variable/CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE.html#variable:CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE

"CMake provides the selected toolchain architecture preference in this
variable (x86, x64, ARM64 or empty)."

Added: 
    

Modified: 
    llvm/docs/GettingStartedVS.rst

Removed: 
    


################################################################################
diff  --git a/llvm/docs/GettingStartedVS.rst b/llvm/docs/GettingStartedVS.rst
index bc5746df66e20..e65fd8fde829d 100644
--- a/llvm/docs/GettingStartedVS.rst
+++ b/llvm/docs/GettingStartedVS.rst
@@ -126,6 +126,15 @@ These instructions were tested with Visual Studio 2019 and Python 3.9.6:
        cmake -S llvm\llvm -B build -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=X86 -Thost=x64
        exit
 
+   .. note::
+     By default, the Visual Studio project files generated by CMake use the
+     32-bit toolset. If you are developing on a 64-bit version of Windows and
+     want to use the 64-bit toolset, pass the ``-Thost=x64`` flag when
+     generating the Visual Studio solution. This requires CMake 3.8.0 or later.
+
+     For Windows on Arm the equivalent is ``-Thost=ARM64``, but this the default
+     for those hosts, so you do not have to use this option.
+
    ``LLVM_ENABLE_PROJECTS`` specifies any additional LLVM projects you want to
    build while ``LLVM_TARGETS_TO_BUILD`` selects the compiler targets. If
    ``LLVM_TARGETS_TO_BUILD`` is omitted by default all targets are built
@@ -149,10 +158,6 @@ These instructions were tested with Visual Studio 2019 and Python 3.9.6:
    * CMake generates project files for all build types. To select a specific
      build type, use the Configuration manager from the VS IDE or the
      ``/property:Configuration`` command-line option when using MSBuild.
-   * By default, the Visual Studio project files generated by CMake use the
-     32-bit toolset. If you are developing on a 64-bit version of Windows and
-     want to use the 64-bit toolset, pass the ``-Thost=x64`` flag when
-     generating the Visual Studio solution. This requires CMake 3.8.0 or later.
 
 13. Start Visual Studio and select configuration: