On Mon, Jan 18, 2021 at 11:56 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote: > > The current llvm/clang build procedure in samples/bpf/README.rst is > out of date. See below that the links are not accessible any more. > > $ git clone http://llvm.org/git/llvm.git > Cloning into 'llvm'... > fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed > $ git clone --depth 1 http://llvm.org/git/clang.git > Cloning into 'clang'... > fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed > > The llvm community has adopted new ways to build the compiler. There are > different ways to build llvm/clang, the Clang Getting Started page [1] has > one way. As Yonghong said, it is better to just copy the build procedure > in Documentation/bpf/bpf_devel_QA.rst to keep consistent. > > I verified the procedure and it is proved to be feasible, so we should > update README.rst to reflect the reality. At the same time, update the > related comment in Makefile. > > [1] https://clang.llvm.org/get_started.html There's also https://www.kernel.org/doc/html/latest/kbuild/llvm.html#getting-llvm (could cross link in rst/sphinx). > > Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> > Acked-by: Yonghong Song <yhs@xxxxxx> > --- > > v2: Update the commit message suggested by Yonghong, > thank you very much. > > samples/bpf/Makefile | 2 +- > samples/bpf/README.rst | 17 ++++++++++------- > 2 files changed, 11 insertions(+), 8 deletions(-) > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile > index 26fc96c..d061446 100644 > --- a/samples/bpf/Makefile > +++ b/samples/bpf/Makefile > @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock += -pthread -lcap > TPROGLDLIBS_xsk_fwd += -pthread > > # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: > -# make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang > +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang > LLC ?= llc > CLANG ?= clang > OPT ?= opt > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst > index dd34b2d..d1be438 100644 > --- a/samples/bpf/README.rst > +++ b/samples/bpf/README.rst > @@ -65,17 +65,20 @@ To generate a smaller llc binary one can use:: > Quick sniplet for manually compiling LLVM and clang > (build dependencies are cmake and gcc-c++):: > > - $ git clone http://llvm.org/git/llvm.git > - $ cd llvm/tools > - $ git clone --depth 1 http://llvm.org/git/clang.git > - $ cd ..; mkdir build; cd build > - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86" Is the BPF target not yet on by default? I frown upon disabling other backends. > - $ make -j $(getconf _NPROCESSORS_ONLN) > + $ git clone https://github.com/llvm/llvm-project.git > + $ mkdir -p llvm-project/llvm/build/install > + $ cd llvm-project/llvm/build > + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \ > + -DLLVM_ENABLE_PROJECTS="clang" \ > + -DBUILD_SHARED_LIBS=OFF \ > + -DCMAKE_BUILD_TYPE=Release \ > + -DLLVM_BUILD_RUNTIME=OFF > + $ ninja > > It is also possible to point make to the newly compiled 'llc' or > 'clang' command via redefining LLC or CLANG on the make command line:: > > - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang > + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang > > Cross compiling samples > ----------------------- > -- > 2.1.0 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/1611042978-21473-1-git-send-email-yangtiezhu%40loongson.cn. -- Thanks, ~Nick Desaulniers
