Hi Steven, Have you considered using the --rtlib switch? It would eliminate the dependency on the system's libgcc, crtbegin/end.o and crti/o.o, for most systems. I don't know exactly how the build system works but I assume there's some way to force a compiler flag. Best regards, Pedro On Fri, 13 Aug 2021 at 14:34, Steven Shi wrote: > 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:* > > *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 > > > > > > -- Pedro Falcato