Ubuntu-20.04 based pytorch/llvm:12.0.0 image (pytorch#794)

* Ubuntu-20.04 based `pytorch/llvm:12.0.0` image

* Also, build clang

* Download llvm-project instead of just llvm

llvm/Dockerfile

@@ -1,6 +1,6 @@
-FROM ubuntu:xenial as dev
+FROM ubuntu:focal as dev
 ARG LLVM_VERSION=9.0.1
-ENV LLVM_URL https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VERSION}/llvm-${LLVM_VERSION}.src.tar.xz
+ENV LLVM_URL https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VERSION}/llvm-project-${LLVM_VERSION}.src.tar.xz
 ENV DEBIAN_FRONTEND noninteractive
 RUN apt-get update && apt-get install -y \
         build-essential \
@@ -14,18 +14,21 @@ RUN apt-get update && apt-get install -y \
 # Build LLVM with CXX11 ABI (default)
 RUN mkdir -p /opt/llvm /tmp/llvm/build
 WORKDIR /tmp/llvm
-RUN curl -fL -o llvm.tar.xz "${LLVM_URL}" && \
-        tar -xf llvm.tar.xz --strip-components=1
+RUN curl -fL -o llvm-project.tar.xz "${LLVM_URL}" && \
+        tar -xf llvm-project.tar.xz --strip-components=1
 WORKDIR /tmp/llvm/build
 RUN cmake -G "Unix Makefiles" \
         -DCMAKE_BUILD_TYPE=MinSizeRel \
         -DLLVM_ENABLE_ASSERTIONS=ON \
         -DCMAKE_INSTALL_PREFIX=/opt/llvm \
         -DLLVM_TARGETS_TO_BUILD="host" \
         -DLLVM_BUILD_TOOLS=OFF \
-        -DLLVM_BUILD_UTILS=OFF \
+        -DLLVM_BUILD_UTILS=ON \
+        -DLLVM_INSTALL_UTILS=ON \
+        -DLLVM_ENABLE_RTTI=ON \
+        -DLLVM_ENABLE_PROJECTS=clang \
         -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON \
-        ../
+        ../llvm/
 RUN make -j"$(nproc --ignore=2)" && make install
 
 # Build LLVM without CXX11 ABI
@@ -39,8 +42,8 @@ RUN cmake -G "Unix Makefiles" \
         -DLLVM_BUILD_TOOLS=OFF \
         -DLLVM_BUILD_UTILS=OFF \
         -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON \
-	-DCMAKE_CXX_FLAGS=-D_GLIBCXX_USE_CXX11_ABI=0 \
-        ../
+        -DCMAKE_CXX_FLAGS=-D_GLIBCXX_USE_CXX11_ABI=0 \
+        ../llvm/
 RUN make -j"$(nproc --ignore=2)" && make install
 
 

llvm/env_vars.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-LLVM_VERSION="9.0.1"
+LLVM_VERSION="12.0.0"