Add build instructions to the README (#27)

Author: j2kun

README.md

@@ -3,6 +3,8 @@
 This is the code repository for a series of articles
 on the [MLIR framework](https://mlir.llvm.org/) for building compilers.
 
+## Articles
+
 1. [Build System (Getting Started)](https://jeremykun.com/2023/08/10/mlir-getting-started/)
 2. [Running and Testing a Lowering](https://jeremykun.com/2023/08/10/mlir-running-and-testing-a-lowering/)
 3. [Writing Our First Pass](https://jeremykun.com/2023/08/10/mlir-writing-our-first-pass/)
@@ -14,3 +16,129 @@ on the [MLIR framework](https://mlir.llvm.org/) for building compilers.
 9. [Canonicalizers and Declarative Rewrite Patterns](https://jeremykun.com/2023/09/20/mlir-canonicalizers-and-declarative-rewrite-patterns/)
 10. [Dialect Conversion](https://jeremykun.com/2023/10/23/mlir-dialect-conversion/)
 11. Lowering through LLVM
+
+
+## Bazel build
+
+Bazel is one of two supported build systems for this tutorial. The other is
+CMake. If you're unfamiliar with Bazel, you can read the tutorials at
+[https://bazel.build/start](https://bazel.build/start). Familiarity with Bazel
+is not required to build or test, but it is required to follow the articles in
+the tutorial series and explained in the first article, [Build System (Getting
+Started)](https://jeremykun.com/2023/08/10/mlir-getting-started/). The CMake
+build is maintained, but was added at article 10 (Dialect Conversion) and will
+not be explained in the articles.
+
+### Prerequisites
+
+Install Bazelisk via instructions at
+[https://github.com/bazelbuild/bazelisk#installation](https://github.com/bazelbuild/bazelisk#installation).
+This should create the `bazel` command on your system.
+
+You should also have a modern C++ compiler on your system, either `gcc` or
+`clang`, which Bazel will detect.
+
+### Build and test
+
+Run
+
+```bash
+bazel build ...:all
+bazel test ...:all
+```
+
+## CMake build
+
+CMake is one of two supported build systems for this tutorial. The other is
+Bazel. If you're unfamiliar with CMake, you can read the tutorials at
+[https://cmake.org/getting-started/](https://cmake.org/getting-started/).
+The CMake build is maintained, but was added at article 10 (Dialect Conversion)
+and will not be explained in the articles.
+
+### Prerequisites
+
+* Make sure you have installed everything needed to build LLVM
+https://llvm.org/docs/GettingStarted.html#software
+* For this recipe Ninja is used so be sure to have it as well installed
+https://github.com/ninja-build/ninja/wiki/Pre-built-Ninja-packages
+
+### Checking out the code
+
+Checkout the tutorial including the LLVM dependency (submodules):
+
+```bash
+git clone --recurse-submodules https://github.com/j2kun/mlir-tutorial.git
+cd mlir-tutorial
+```
+
+### Building dependencies
+
+Note: The following steps are suitable for macOs and use ninja as building
+system, they should not be hard to adapt for your environment.
+
+*Build LLVM/MLIR*
+
+```bash
+#!/bin/sh
+
+BUILD_SYSTEM=Ninja
+BUILD_TAG=ninja
+THIRDPARTY_LLVM_DIR=$PWD/externals/llvm-project
+BUILD_DIR=$THIRDPARTY_LLVM_DIR/build
+INSTALL_DIR=$THIRDPARTY_LLVM_DIR/install
+
+mkdir -p $BUILD_DIR
+mkdir -p $INSTALL_DIR
+
+pushd $BUILD_DIR
+
+cmake ../llvm -G $BUILD_SYSTEM \
+      -DCMAKE_CXX_COMPILER="$(xcrun --find clang++)" \
+      -DCMAKE_C_COMPILER="$(xcrun --find clang)" \
+      -DCMAKE_INSTALL_PREFIX=$INSTALL_DIR \
+      -DLLVM_LOCAL_RPATH=$INSTALL_DIR/lib \
+      -DLLVM_PARALLEL_COMPILE_JOBS=7 \
+      -DLLVM_PARALLEL_LINK_JOBS=1 \
+      -DLLVM_BUILD_EXAMPLES=OFF \
+      -DLLVM_INSTALL_UTILS=ON \
+      -DCMAKE_OSX_ARCHITECTURES="$(uname -m)" \
+      -DCMAKE_BUILD_TYPE=Release \
+      -DLLVM_ENABLE_ASSERTIONS=ON \
+      -DLLVM_CCACHE_BUILD=ON \
+      -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
+      -DLLVM_ENABLE_PROJECTS='mlir' \
+      -DDEFAULT_SYSROOT="$(xcrun --show-sdk-path)" \
+      -DCMAKE_OSX_SYSROOT="$(xcrun --show-sdk-path)"
+
+cmake --build . --target check-mlir
+
+popd
+```
+
+### Build and test
+
+```bash
+#!/bin/sh
+
+BUILD_SYSTEM="Ninja"
+BUILD_DIR=./build-`echo ${BUILD_SYSTEM}| tr '[:upper:]' '[:lower:]'`
+
+rm -rf $BUILD_DIR
+mkdir $BUILD_DIR
+pushd $BUILD_DIR
+
+LLVM_BUILD_DIR=externals/llvm-project/build
+cmake -G $BUILD_SYSTEM .. \
+    -DLLVM_DIR="$LLVM_BUILD_DIR/lib/cmake/llvm" \
+    -DMLIR_DIR="$LLVM_BUILD_DIR/lib/cmake/mlir" \
+    -DCMAKE_BUILD_TYPE=Debug
+
+popd
+
+cmake --build $BUILD_DIR --target MLIRAffineFullUnrollPasses
+cmake --build $BUILD_DIR --target MLIRMulToAddPasses
+cmake --build $BUILD_DIR --target mlir-headers
+cmake --build $BUILD_DIR --target mlir-doc
+cmake --build $BUILD_DIR --target tutorial-opt
+cmake --build $BUILD_DIR --target check-mlir-tutorial
+```