Re: [edk2-devel] [Patch 0/7] Add new CLANG8ELF tool chain for new LLVM/CLANG8

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On Fri, 26 Apr 2019 at 16:43, Liming Gao <liming.gao@intel.com> wrote:
>
> BZ:https://bugzilla.tianocore.org/show_bug.cgi?id=1603
> LLVM/CLANG8 formal release http://releases.llvm.org/download.html#8.0.0
> It can be downloaded and installed in Windows/Linux/Mac OS.
>
> CLANG8ELF tool chain is added to generate ELF image, and convert to PE/COFF.
> On Windows OS, set CLANG_HOST_BIN=n, set CLANG8_BIN=LLVM installed directory
> CLANG_HOST_BIN is used CLANG_HOST_PREFIX. Prefix n is for nmake.
> For example:
>   set CLANG_HOST_BIN=n
>   set CLANG8_BIN=C:\Program Files\LLVM\bin\
> On Linux/Mac, export CLANG8_BIN=LLVM installed directory, CLANG_HOST_BIN is
> not required, because there is no prefix for make.
> For example:
>   export CLANG8_BIN=/home/clang8/bin/
>
> This tool chain can be used to compile the firmware code. On windows OS,
> Visual Studio is still required to compile BaseTools C tools and
> provide nmake.exe for makefile. On Linux/Mac OS, gcc is used to compile
> BaseTools C tools. make is used for makefile.
>
> This tool chain is verified on OVMF Ia32, X64 and Ia32X64 to boot Shell.
> This tool chain is verified in Windows/Linux and Mac OS.
>

Hello Liming,

This series confuses me. The existing CLANGxx toolchains already use
GenFw and ELF to PE/COFF conversion, so the name CLANG8ELF is
misleading.

Also, it seems that the primary difference is using LLD instead of GNU
ld, but this has nothing to do with the Clang version.

What is the benefit of using LLD over GNU ld? It seems we are working
around various incompatibilities, and I think this is only justified
if LLD has some benefit over GNU ld.

Thanks,
Ard.



> Liming Gao (7):
>   BaseTools: Add ClangBase.lds for CLANG8 tool chain with max-page-size
>   BaseTools GenFw: Support CLANG8ELF with conversion ELF to PE/COFF
>     image
>   BaseTools: Update build_rule.template for ASLC rule with full C flags
>   BaseTools: Update build_rule to skip CLANG resource section generation
>   BaseTools: Update tools_def.template to directly refer to AutoGen.h
>   BaseTools: Add new CLANG8ELF tool chain for new LLVM/CLANG8
>   OvmfPkg: Update DSC/FDF to support CLANG8ELF tool chain
>
>  BaseTools/Source/C/GenFw/Elf32Convert.c |  12 +---
>  BaseTools/Source/C/GenFw/Elf64Convert.c |  11 +--
>  BaseTools/Conf/build_rule.template      |   8 +--
>  BaseTools/Conf/tools_def.template       | 121 +++++++++++++++++++++++++++++---
>  BaseTools/Scripts/ClangBase.lds         |  79 +++++++++++++++++++++
>  OvmfPkg/OvmfPkgIa32.dsc                 |   4 +-
>  OvmfPkg/OvmfPkgIa32.fdf                 |   2 +-
>  OvmfPkg/OvmfPkgIa32X64.dsc              |   4 +-
>  OvmfPkg/OvmfPkgIa32X64.fdf              |   2 +-
>  OvmfPkg/OvmfPkgX64.dsc                  |   4 +-
>  OvmfPkg/OvmfPkgX64.fdf                  |   2 +-
>  11 files changed, 213 insertions(+), 36 deletions(-)
>  create mode 100644 BaseTools/Scripts/ClangBase.lds
>
> --
> 2.13.0.windows.1
>
>
> 
>