update INSTALL.md for new llvm source compilation
clang/llvm has moved from old svn with git mirror to
github based source control. The new github address is
which includes clang, llvm and other related projects.
This patch updated instruction how to build clang/llvm library
with new llvm-project setup.
@@ -532,12 +532,12 @@ sudo /usr/share/bcc/tools/execsnoop
## Build LLVM and Clang development libs
```
-git clone http://llvm.org/git/llvm.git
-cd llvm/tools; git clone http://llvm.org/git/clang.git
-cd ..; mkdir -p build/install; cd build
-cmake -G "Unix Makefiles" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
+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" \
-DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=$PWD/install ..
-make
-make install
+ninja && ninja install
export PATH=$PWD/install/bin:$PATH
```
