Liming, The MSVC is required only because the Windows SDK Universal C runtime (UCRT) library depends on the MSVC. Please see the dependency description here: “When you install Visual C++, Visual Studio setup installs the subset of the Windows 10 SDK required to use the UCRT.” https://docs.microsoft.com/en-us/cpp/c-runtime-library/crt-library-features?view=msvc-160. If the MSVC is not installed, the ucrt will complain cannot find the msvc header files. Below is an example: C:\Program Files\LLVM\bin\clang -c -I .. -I ../Include/Common -I ../Include/ -I ../Include/IndustryStandard -I ../Common/ -I .. -I . -I ../Include/X64/ -I "" -MD -fshort-wchar -fno-strict-aliasing -fwrapv -fno-delete-null-pointer-checks -Wall -Werror -Wno-deprecated-declarations -Wno-self-assign -Wno-unused-result -nostdlib -Wno-unused-function -g -m32 -O2 BasePeCoff.c -o BasePeCoff.o In file included from BasePeCoff.c:13: In file included from ../Common\CommonLib.h:14: In file included from C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt\assert.h:12: C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt\corecrt.h:10:10: fatal error: 'vcruntime.h' file not found #include ^~~~~~~~~~~~~ 1 error generated. BTW, the compiler dependency requirement also exists in Linux side. Below is the Linux GCC CRT library example. Although I build with clang, it still needs link the crt libraries in GCC installation. Below is an example: $ /home/jshi19/llvm/clang+llvm-11.0.0-x86_64-linux-gnu-ubuntu-20.04/bin/clang -o ../bin/LzmaCompress LzmaCompress.o Sdk/C/Alloc.o Sdk/C/LzFind.o Sdk/C/LzmaDec.o Sdk/C/LzmaEnc.o Sdk/C/7zFile.o Sdk/C/7zStream.o Sdk/C/Bra86.o -L../libs -lCommon -### clang version 11.0.0 (https://github.com/llvm/llvm-project.git 0160ad802e899c2922bc9b29564080c22eb0908c) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /home/jshi19/llvm/clang+llvm-11.0.0-x86_64-linux-gnu-ubuntu-20.04/bin "/usr/bin/ld" "-z" "relro" "--hash-style=gnu" "--eh-frame-hdr" "-m" "elf_x86_64" "-dynamic-linker" "/lib64/ld-linux-x86-64.so.2" "-o" "../bin/LzmaCompress" "/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crt1.o" "/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crti.o" "/usr/lib/gcc/x86_64-linux-gnu/10/crtbegin.o" "-L../libs" "-L/usr/lib/gcc/x86_64-linux-gnu/10" "-L/usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/lib/../lib64" "-L/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu" "-L/lib/x86_64-linux-gnu" "-L/lib/../lib64" "-L/usr/lib/x86_64-linux-gnu" "-L/usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/lib" "-L/usr/lib/gcc/x86_64-linux-gnu/10/../../.." "-L/home/jshi19/llvm/clang+llvm-11.0.0-x86_64-linux-gnu-ubuntu-20.04/bin/../lib" "-L/lib" "-L/usr/lib" "LzmaCompress.o" "Sdk/C/Alloc.o" "Sdk/C/LzFind.o" "Sdk/C/LzmaDec.o" "Sdk/C/LzmaEnc.o" "Sdk/C/7zFile.o" "Sdk/C/7zStream.o" "Sdk/C/Bra86.o" "-lCommon" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "/usr/lib/gcc/x86_64-linux-gnu/10/crtend.o" "/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crtn.o" Thanks Steven Shi Intel\SATG\SFP\FIA (Firmware Infrastructure Automation) From: devel@edk2.groups.io On Behalf Of gaoliming Sent: Friday, August 13, 2021 9:18 AM To: devel@edk2.groups.io; yuqi.chen@mail.utoronto.ca Subject: 回复: [edk2-devel] [2021-gsoc-llvm-gnumake]: proposal for building using llvm/gnumake Yuqi: On Windows, can Clang + make combination drop the dependency of Visual studio? If I don’t install Visual studio 2015 or 2017, I only install LLVM, can I fully compile BaseTools and Edk2 code? Thanks Liming 发件人: devel@edk2.groups.io > 代表 Yuqi Chen 发送时间: 2021年8月12日 9:52 收件人: devel@edk2.groups.io 主题: [edk2-devel] [2021-gsoc-llvm-gnumake]: proposal for building using llvm/gnumake Hi, I want to push my change to my codes to edk2-staging, yet it seems like I don’t have permission to do so: [cid:image001.png@01D79030.EEE25800] My mentor and I have enabled edk2 building using llvm+make and gnumake+clang in windows command prompt. The attached patch indicates changes we made to make this happen. I also attach the readme file to go through the steps to build Basetools. Please review our codes and thank you very much for your time. Best regards, Yuqi