diff --git a/scripts/build-llvm/build.ps1 b/scripts/build-llvm/build.ps1
new file mode 100755
index 000000000..62277b859
--- /dev/null
+++ b/scripts/build-llvm/build.ps1
@@ -0,0 +1,69 @@
+$LLVM_VERSION = $args[0]
+$LLVM_REPO_URL = $args[1]
+
+if ([string]::IsNullOrEmpty($LLVM_REPO_URL)) {
+    $LLVM_REPO_URL = "https://github.com/llvm/llvm-project.git"
+}
+
+if ([string]::IsNullOrEmpty($LLVM_VERSION)) {
+    Write-Output "Usage: $PSCommandPath <llvm-version> <llvm-repository-url>"
+    Write-Output ""
+    Write-Output "# Arguments"
+    Write-Output "  llvm-version         The name of a LLVM release branch without the 'release/' prefix"
+    Write-Output "  llvm-repository-url  The URL used to clone LLVM sources (default: https://github.com/llvm/llvm-project.git)"
+
+	exit 1
+}
+
+# Clone the LLVM project.
+if (-not (Test-Path -Path "llvm-project" -PathType Container)) {
+	git clone "$LLVM_REPO_URL" llvm-project
+}
+
+Set-Location llvm-project
+git fetch origin
+git checkout "release/$LLVM_VERSION"
+git reset --hard origin/"release/$LLVM_VERSION"
+
+# Create a directory to build the project.
+New-Item -Path "build" -Force -ItemType "directory"
+Set-Location build
+
+# Create a directory to receive the complete installation.
+New-Item -Path "install" -Force -ItemType "directory"
+
+# Adjust compilation based on the OS.
+$CMAKE_ARGUMENTS = ""
+
+# Adjust cross compilation
+$CROSS_COMPILE = ""
+
+# Run `cmake` to configure the project.
+cmake `
+  -G "Visual Studio 16 2019" `
+  -DCMAKE_BUILD_TYPE=MinSizeRel `
+  -DCMAKE_INSTALL_PREFIX=destdir `
+  -DLLVM_ENABLE_PROJECTS="clang;lld" `
+  -DLLVM_ENABLE_TERMINFO=OFF `
+  -DLLVM_ENABLE_ZLIB=OFF `
+  -DLLVM_INCLUDE_DOCS=OFF `
+  -DLLVM_INCLUDE_EXAMPLES=OFF `
+  -DLLVM_INCLUDE_GO_TESTS=OFF `
+  -DLLVM_INCLUDE_TESTS=OFF `
+  -DLLVM_INCLUDE_TOOLS=ON `
+  -DLLVM_INCLUDE_UTILS=OFF `
+  -DLLVM_OPTIMIZED_TABLEGEN=ON `
+  -DLLVM_TARGETS_TO_BUILD="X86;AArch64" `
+  $CROSS_COMPILE `
+  $CMAKE_ARGUMENTS `
+  ../llvm
+
+# Showtime!
+cmake --build . --config Release
+
+# Not using DESTDIR here, quote from
+# https://cmake.org/cmake/help/latest/envvar/DESTDIR.html
+# > `DESTDIR` may not be used on Windows because installation prefix
+# > usually contains a drive letter like in `C:/Program Files` which cannot
+# > be prepended with some other prefix.
+cmake --install . --strip --config Release
diff --git a/scripts/build-llvm/build.sh b/scripts/build-llvm/build.sh
new file mode 100755
index 000000000..56f05da22
--- /dev/null
+++ b/scripts/build-llvm/build.sh
@@ -0,0 +1,84 @@
+#!/bin/bash
+
+# Display all commands before executing them.
+set -o errexit
+set -o errtrace
+
+LLVM_VERSION=$1
+LLVM_REPO_URL=${2:-https://github.com/llvm/llvm-project.git}
+LLVM_CROSS="$3"
+
+if [[ -z "$LLVM_REPO_URL" || -z "$LLVM_VERSION" ]]
+then
+  echo "Usage: $0 <llvm-version> <llvm-repository-url> [aarch64]"
+  echo
+  echo "# Arguments"
+  echo "  llvm-version         The name of a LLVM release branch without the 'release/' prefix"
+  echo "  llvm-repository-url  The URL used to clone LLVM sources (default: https://github.com/llvm/llvm-project.git)"
+  echo "  aarch64              To cross-compile an aarch64 version of LLVM"
+
+  exit 1
+fi
+
+# Clone the LLVM project.
+if [ ! -d llvm-project ]
+then
+  git clone "$LLVM_REPO_URL" llvm-project
+fi
+
+
+cd llvm-project
+git fetch origin
+git checkout "release/$LLVM_VERSION"
+git reset --hard origin/"release/$LLVM_VERSION"
+
+# Create a directory to build the project.
+mkdir -p build
+cd build
+
+# Create a directory to receive the complete installation.
+mkdir -p install
+
+# Adjust compilation based on the OS.
+CMAKE_ARGUMENTS=""
+
+case "${OSTYPE}" in
+    darwin*) ;;
+    linux*) ;;
+    *) ;;
+esac
+
+# Adjust cross compilation
+CROSS_COMPILE=""
+
+case "${LLVM_CROSS}" in
+    aarch64*) CROSS_COMPILE="-DLLVM_HOST_TRIPLE=aarch64-linux-gnu" ;;
+    *) ;;
+esac
+
+# Run `cmake` to configure the project.
+cmake \
+  -G "Unix Makefiles" \
+  -DCMAKE_BUILD_TYPE=MinSizeRel \
+  -DCMAKE_INSTALL_PREFIX="/" \
+  -DLLVM_ENABLE_PROJECTS="clang;lld" \
+  -DLLVM_ENABLE_TERMINFO=OFF \
+  -DLLVM_ENABLE_ZLIB=OFF \
+  -DLLVM_INCLUDE_DOCS=OFF \
+  -DLLVM_INCLUDE_EXAMPLES=OFF \
+  -DLLVM_INCLUDE_GO_TESTS=OFF \
+  -DLLVM_INCLUDE_TESTS=OFF \
+  -DLLVM_INCLUDE_TOOLS=ON \
+  -DLLVM_INCLUDE_UTILS=OFF \
+  -DLLVM_OPTIMIZED_TABLEGEN=ON \
+  -DLLVM_TARGETS_TO_BUILD="X86;AArch64" \
+  "${CROSS_COMPILE}" \
+  "${CMAKE_ARGUMENTS}" \
+  ../llvm
+
+# Showtime!
+cmake --build . --config MinSizeRel
+DESTDIR=destdir cmake --install . --strip --config MinSizeRel
+
+# move usr/bin/* to bin/ or llvm-config will be broken
+mv destdir/usr/bin/* destdir/bin/