### Example: Stand-alone Clang Build

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStarted.rst

A shell script demonstrating the process of building LLVM, installing it, and then building Clang as a stand-alone project.

```shell
#!/bin/sh

build_llvm=`pwd`/build-llvm
build_clang=`pwd`/build-clang
installprefix=`pwd`/install
llvm=`pwd`/llvm-project
mkdir -p $build_llvm
mkdir -p $installprefix

cmake -G Ninja -S $llvm/llvm -B $build_llvm \
      -DLLVM_INSTALL_UTILS=ON \
      -DCMAKE_INSTALL_PREFIX=$installprefix \
      -DCMAKE_BUILD_TYPE=Release

ninja -C $build_llvm install

cmake -G Ninja -S $llvm/clang -B $build_clang \
      -DLLVM_EXTERNAL_LIT=$build_llvm/utils/lit \
      -DLLVM_ROOT=$installprefix

ninja -C $build_clang
```

--------------------------------

### Test Polly Installation

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/polly/www/get_started.html

Runs the test suite for Polly after building.

```bash
cmake --build . --target check-polly
```

--------------------------------

### LLVM Installation for Stand-alone Builds

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStarted.rst

Installs LLVM with utility files, specifying the installation prefix, to be used for stand-alone builds of other projects.

```console
cmake -G Ninja -S path/to/llvm-project/llvm -B $builddir \
      -DLLVM_INSTALL_UTILS=ON \
      -DCMAKE_INSTALL_PREFIX=/path/to/llvm/install/prefix \
      < other options >

ninja -C $builddir install
```

--------------------------------

### Install LLVM

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStarted.rst

Installs LLVM header files, libraries, tools, and documentation to the path specified by CMAKE_INSTALL_PREFIX.

```console
make install
```

--------------------------------

### Install GCC from Source

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStarted.rst

Provides console commands to download, verify, build, and install a specific version of GCC from source. This is useful for systems with outdated default compilers.

```console
%gcc_version=7.4.0
%wget https://ftp.gnu.org/gnu/gcc/gcc-${gcc_version}/gcc-${gcc_version}.tar.bz2
%wget https://ftp.gnu.org/gnu/gcc/gcc-${gcc_version}/gcc-${gcc_version}.tar.bz2.sig
%wget https://ftp.gnu.org/gnu/gnu-keyring.gpg
%signature_invalid=`gpg --verify --no-default-keyring --keyring ./gnu-keyring.gpg gcc-${gcc_version}.tar.bz2.sig`
%if [ $signature_invalid ]; then echo "Invalid signature" ; exit 1 ; fi
%tar -xvjf gcc-${gcc_version}.tar.bz2
%cd gcc-${gcc_version}
%./contrib/download_prerequisites
%cd ..
%mkdir gcc-${gcc_version}-build
%cd gcc-${gcc_version}-build
%${PWD}/../gcc-${gcc_version}/configure --prefix=$HOME/toolchains --enable-languages=c,c++
%make -j$(nproc)
%make install
```

--------------------------------

### LLVM Installation Steps (Windows Batch)

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStartedVS.rst

This snippet outlines the command-line steps to set up the LLVM development environment on Windows. It includes changing directories, registering DLLs, installing Python packages, and cloning the LLVM source code repository.

```bat
c:
cd \
regsvr32 "%VSINSTALLDIR%\DIA SDK\bin\msdia140.dll"
regsvr32 "%VSINSTALLDIR%\DIA SDK\bin\amd64\msdia140.dll"
pip install psutil
git clone https://github.com/llvm/llvm-project.git llvm
```

--------------------------------

### Clang Preprocessing Example

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/clang/www/get_started.html

Shows how to use the Clang driver to preprocess a C source file, displaying the output after the preprocessing stage.

```C
typedef float V __attribute__((vector_size(16)));
V foo(V a, V b) { return a+b*a; }
```

```Shell
clang ~/t.c -E
```

--------------------------------

### Native Assembly to Executable

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStarted.rst

Provides commands for assembling native assembly language files into executable programs, with platform-specific examples for Solaris and other systems.

```console
# On Solaris
% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
```

```console
# On others
% gcc hello.s -o hello.native
```

--------------------------------

### Clang CMake Configuration

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/clang/www/get_started.html

Example CMake command to configure the build for LLVM and Clang, specifying projects, build type, and generator.

```cmake
cmake -DLLVM_ENABLE_PROJECTS=clang -DCMAKE_BUILD_TYPE=Release -G "Unix Makefiles" ../llvm
```

--------------------------------

### Example jscop export output

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/polly/docs/HowToManuallyUseTheIndividualPiecesOfPolly.rst

Shows example output from the jscop export process, indicating which SCoPs were written to .jscop files.

```text
        [...]Writing JScop '%for.cond1.preheader---%for.end19' in function 'init_array' to './init_array___%for.cond1.preheader---%for.end19.jscop'.

        Writing JScop '%for.cond1.preheader---%for.end30' in function 'main' to './main___%for.cond1.preheader---%for.end30.jscop'.
```

--------------------------------

### Compile with Polly

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/polly/www/get_started.html

Compiles a C program using the Polly-enabled clang compiler.

```bash
bin/clang -O3 -mllvm -polly hello.c
```

--------------------------------

### MLIR Operation Constant Folder Example

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/mlir/docs/Tutorials/QuickstartRewrites.md

Provides a C++ example of a constant folder method for an MLIR operation, demonstrating how to handle folding logic.

```c++
OpFoldResult SpecificOp::fold(ArrayRef<Attribute> constOperands) {
  if (unable_to_fold)
    return {};
  ....
  return val;
}
```

--------------------------------

### Clone LLVM Project

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/polly/www/get_started.html

Clones the LLVM project repository, which includes Polly. Supports both full and shallow clones.

```bash
git clone https://github.com/llvm/llvm-project.git
```

```bash
git clone --depth 1 https://github.com/llvm/llvm-project.git
```

--------------------------------

### Polly Analysis Output Example

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/polly/docs/HowToManuallyUseTheIndividualPiecesOfPolly.rst

Example output from Polly's analysis, detailing the structure of a detected SCoP in the 'init_array' function, including loop depth and context.

```text
[...]Printing analysis 'Polly - Create polyhedral description of Scops' for region: 'for.cond1.preheader => for.end19' in function 'init_array':
    Function: init_array
    Region: %for.cond1.preheader---%for.end19
    Max Loop Depth:  2
        Invariant Accesses: {
        }
        Context:
        {  :  }
        Assumed Context:
        {  :  }
```

--------------------------------

### MLIR Python Bindings Development Setup

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/mlir/docs/Bindings/Python.md

Steps to set up a Python virtual environment and install MLIR Python dependencies.

```Shell
# Make sure your 'python' is what you expect. Note that on multi-python
# systems, this may have a version suffix, and on many Linuxes and MacOS where
# python2 and python3 co-exist, you may also want to use `python3`.
which python
python -m venv ~/.venv/mlirdev
source ~/.venv/mlirdev/bin/activate

# Note that many LTS distros will bundle a version of pip itself that is too
# old to download all of the latest binaries for certain platforms.
# The pip version can be obtained with `python -m pip --version`, and for
# Linux specifically, this should be cross checked with minimum versions
# here: https://github.com/pypa/manylinux
# It is recommended to upgrade pip:
python -m pip install --upgrade pip


# Now the `python` command will resolve to your virtual environment and
# packages will be installed there.
python -m pip install -r mlir/python/requirements.txt

# Now run `cmake`, `ninja`, et al.
```

--------------------------------

### Build Example Directory Setup

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/libc/examples/README.md

Steps to set up the build directory for an example program. This involves navigating to the example's directory, creating a 'build' subdirectory, and changing into it.

```bash
cd <example directory>
mkdir build
cd build
```

--------------------------------

### Install flang and create version file

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/flang/docs/GettingStarted.md

Commands to install the built flang components and create a version marker file in the installation directory.

```bash
ninja install

echo "latest" > $INSTALLDIR/bin/versionrc
```

--------------------------------

### Clang Build and Run

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/clang/www/get_started.html

Instructions for building and running Clang on Unix-like systems, including checking out the LLVM project, configuring with CMake, building, and testing.

```bash
git clone https://github.com/llvm/llvm-project.git
```

```bash
git clone --depth=1 https://github.com/llvm/llvm-project.git
```

```bash
cd llvm-project
git fetch --unshallow
```

```bash
cd llvm-project
mkdir build
cd build
```

```bash
cmake -DLLVM_ENABLE_PROJECTS=clang -DCMAKE_BUILD_TYPE=Release -G "Unix Makefiles" ../llvm
```

```bash
make
```

```bash
make check-clang
```

```bash
clang --help
```

```bash
clang file.c -fsyntax-only
```

```bash
clang file.c -S -emit-llvm -o -
```

```bash
clang file.c -S -emit-llvm -o - -O3
```

```bash
clang file.c -S -O3 -o -
```

--------------------------------

### Install LLVM Dependencies with Chocolatey

Source: https://github.com/rocm/rocmlir/blob/develop/external/llvm-project/llvm/docs/GettingStartedVS.rst

Installs Git, CMake, and Python 3 using Chocolatey, and installs the psutil library using pip.

```bat
choco install -y git cmake python3
pip3 install psutil
```