The current llvm/clang build procedure in samples/bpf/README.rst is out of date.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 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" - $ 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
