1 files changed, 159 insertions, 0 deletions
diff --git a/external/build-llvm.ps1 b/external/build-llvm.ps1
new file mode 100644
index 000000000..b777d2173
--- /dev/null
+++ b/external/build-llvm.ps1
@@ -0,0 +1,159 @@
+# PowerShell script to fetch, build, and install LLVM for Slang
+
+# Set script to fail on errors
+$ErrorActionPreference = "Stop"
+
+function Show-Help {
+    Write-Host "Fetch, build and install LLVM for Slang
+
+Options:
+  --repo: The source git repo, default: $repo
+  --branch: The branch (or tag) to fetch, default: $branch
+  --source-dir: Unpack and build in this directory: default $source_dir
+  --config: The configuration to build, default $config
+  --install-prefix: Install under this prefix
+  --: Any following arguments will be passed to the CMake configuration command
+"
+}
+
+function Msg {
+    Write-Host "$args" -ForegroundColor Yellow
+}
+
+function Fail {
+    Msg "$args"
+    exit 1
+}
+
+function New-TemporaryDirectory {
+  $tmp = [System.IO.Path]::GetTempPath() # Not $env:TEMP, see https://stackoverflow.com/a/946017
+  $name = (New-Guid).ToString("N")
+  New-Item -ItemType Directory -Path (Join-Path $tmp $name)
+}
+
+# Check if required programs are available
+$requiredPrograms = "cmake", "git"
+foreach ($prog in $requiredPrograms) {
+    if (-not (Get-Command $prog -ErrorAction SilentlyContinue)) {
+        Msg "This script needs $prog, but it isn't in PATH"
+        $missingBin = $true
+    }
+}
+if ($missingBin) {
+    exit 1
+}
+
+# Temp directory with cleanup on exit
+$tempDir = New-TemporaryDirectory
+$cleanup = {
+    if ($tempDir) {
+        Remove-Item -Recurse -Force $tempDir
+    }
+    exit $lastExitCode
+}
+$null = Register-EngineEvent PowerShell.Exiting -Action $cleanup
+
+# Default values
+$repo = "https://github.com/llvm/llvm-project"
+$branch = "llvmorg-13.0.1"
+$sourceDir = $tempDir.FullName
+$installPrefix = ""
+$config = "Release"
+$extraArguments = @()
+
+# Argument parsing
+for ($i = 0; $i -lt $args.Length; $i++) {
+    switch ($args[$i]) {
+        "--help" {
+            Show-Help
+            exit
+        }
+        "--repo" {
+            $repo = $args[++$i]
+        }
+        "--branch" {
+            $branch = $args[++$i]
+        }
+        "--source-dir" {
+            $sourceDir = $args[++$i]
+        }
+        "--config" {
+            $config = $args[++$i]
+        }
+        "--install-prefix" {
+            $installPrefix = $args[++$i]
+        }
+        "--" {
+            $extraArguments = $args[$i + 1..$args.Length]
+            break
+        }
+        default {
+            Msg "Unknown parameter passed: $($args[$i])"
+            Show-Help
+            exit 1
+        }
+    }
+}
+
+if (-not $repo) { Fail "please set --repo" }
+if (-not $branch) { Fail "please set --branch" }
+if (-not $sourceDir) { Fail "please set --source-dir" }
+if (-not $config) { Fail "please set --config" }
+if (-not $installPrefix) { Fail "please set --install-prefix" }
+
+# Fetch LLVM from the repo
+Msg "##########################################################"
+Msg "# Fetching LLVM from $repo at $branch"
+Msg "##########################################################"
+# git clone --depth 1 --branch $branch $repo $sourceDir
+
+# Configure LLVM with CMake
+Msg "##########################################################"
+Msg "# Configuring LLVM in $sourceDir"
+Msg "##########################################################"
+$msvcRuntimeLib = "MultiThreaded"
+if ($config -eq 'Debug')
+{
+    $msvcRuntimeLib = "MultiThreadedDebug"
+}
+$cmakeArgumentsForSlang = @(
+    "-DLLVM_BUILD_LLVM_C_DYLIB=0"
+    "-DLLVM_INCLUDE_BENCHMARKS=0"
+    "-DLLVM_INCLUDE_DOCS=0"
+    "-DLLVM_INCLUDE_EXAMPLES=0"
+    "-DLLVM_INCLUDE_TESTS=0"
+    "-DLLVM_ENABLE_TERMINFO=0"
+    "-DCLANG_BUILD_TOOLS=0"
+    "-DCLANG_ENABLE_STATIC_ANALYZER=0"
+    "-DCLANG_ENABLE_ARCMT=0"
+    "-DCLANG_INCLUDE_DOCS=0"
+    "-DCLANG_INCLUDE_TESTS=0"
+    "-DLLVM_ENABLE_PROJECTS=clang"
+    "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64"
+    "-DLLVM_BUILD_TOOLS=0"
+    "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded$<$<CONFIG:Debug>:Debug>"
+    "-DLLVM_USE_CRT_RELEASE=MT"
+    "-DLLVM_USE_CRT_DEBUG=MTd"
+)
+
+$buildDir = Join-Path $sourceDir "build"
+New-Item -Path $buildDir -ItemType Directory -Force
+
+cmake -S $sourceDir\llvm -B $buildDir $cmakeArgumentsForSlang + $extraArguments
+
+# Build LLVM
+Msg "##########################################################"
+Msg "# Building LLVM in $buildDir"
+Msg "##########################################################"
+cmake --build $buildDir -j --config $config
+
+# Install LLVM
+Msg "##########################################################"
+Msg "# Installing LLVM to $installPrefix"
+Msg "##########################################################"
+cmake --install $buildDir --prefix $installPrefix --config $config
+
+Msg "##########################################################"
+Msg "LLVM installed in $installPrefix"
+Msg "Please add $installPrefix to CMAKE_PREFIX_PATH"
+Msg "##########################################################"