Using Visual Studio 2022 ClangCL to build LLVMPipe

Requirements

• Install Python3 and use pip to install
  • mako
  • meson
  • psutil
• download the Win Flex-Bisn portable and extract to a folder

Build LLVM 15.0.2

• clone the llvm project to llvm and checkout 15.0.2

• set PATH=%PATH%;<absolute Flex and Bison Path>

• Configure the LLVM

cmake -S llvm\llvm -B buildllvm -DLLVM_TARGETS_TO_BUILD=X86 \
-DLLVM_USE_CRT_RELEASE=MT -DLLVM_USE_CRT_DEBUG=MTd \
-DCMAKE_INSTALL_PREFIX=E:\LLVM15.0.2 \
-G "Visual Studio 17 2022" -Ax64 -T ClangCL

• msbuild /p:Configuration=Release INSTALL.vcxproj

Build LLVMPipe 22.2.0

• Set clang-cl for meson

set CC=clang-cl
set CXX=clang-cl
set CC_LD=lld-link
set WINDRES=llvm-rc

• Find windows.py in mesonbuild's module folder and add

('/?', '^.*Resource Converter*$', ResourceCompilerType.rc) to

for (arg, match, rc_type) in [
                ('/?', '^.*Microsoft.*Resource Compiler.*$', ResourceCompilerType.rc),
                ('--version', '^.*GNU windres.*$', ResourceCompilerType.windres),
                ('--version', '^.*Wine Resource Compiler.*$', ResourceCompilerType.wrc),
        ]:

if the code doesn't contain output string of llvm-rc /?. Otherwise the meson cannot find llvm-rc.

• set PATH=%PATH%;<LLVM INSTALL PREFIX>/bin

• set LLVM=<LLVM INSTALL PREFIX> (not necessary?)

• Configure the Mesa3d

meson setup --backend=vs2022 builddir/ -Dbuildtype=release \
-Db_vscrt=static_from_buildtype \
-Dosmesa=true \
-Ddri-drivers= \
-Dgallium-drivers=swrast \
-Dvulkan-drivers=swrast \
-Db_vscrt=static_from_buildtype

• meson compile -C builddir
• meson install -C builddir --destdir <INSTALL_PREFIX>

Known issues for mesa22.2.0 and LLVM 15.0.2

conflicting types

make sure the function signature are the same for both declaration and definition, if not modify it

unresolve symbol

Add following libs to vulkan_lvp, osmesa and libgallium_wgl projects <LLVM INSTALL PREFIX>/lib/LLVMObjCARCOpts.lib <LLVM INSTALL PREFIX>/lib/LLVMPasses.lib

lld unknown file type

Remove the osmesa.sym in linker option of osmesa

Use the batch files

Use the batch file to build

• build_llvm.bat needs admminstrator privilege

Usage

OpenGL

Place the Dlls (except the vulan_lvp.dll) to the application folder Some environment varialbes can be overrided, e.g.

set MESA_GL_VERSION_OVERRIDE=4.6
set MESA_GLSL_VERSION_OVERRIDE=460

Vulkan

Set environment variable

set VK_ICD_FILENAMES=<INSTALL_PREFIX>\share\vulkan\icd.d\lvp_icd.x86_64.json

Make sure the json file contains right path for dll