utils: build early swift-driver on Windows

This prepares the swift-driver building on Windows. By statically
linking the runtime and its dependencies, this will allow us to avoid
the runtime shuffling that is required to get the runtime required to
get the swift-driver working.

Author: compnerd

utils/build.ps1

@@ -674,6 +674,7 @@ function Invoke-BuildStep {
 enum Project {
   BuildTools
   RegsGen2
+  EarlySwiftDriver
 
   Compilers
   FoundationMacros
@@ -1203,10 +1204,10 @@ function Get-PinnedToolchainToolsDir() {
     "unknown-Asserts-development.xctoolchain", "usr", "bin")
 }
 
-function Get-PinnedToolchainSDK() {
+function Get-PinnedToolchainSDK([OS] $OS = $BuildPlatform.OS, [string] $Identifier = $OS.ToString()) {
   return [IO.Path]::Combine("$BinaryCache\", "toolchains", $PinnedToolchain,
     "LocalApp", "Programs", "Swift", "Platforms", (Get-PinnedToolchainVersion),
-    "Windows.platform", "Developer", "SDKs", "Windows.sdk")
+    "$($OS.ToString()).platform", "Developer", "SDKs", "$Identifier.sdk")
 }
 
 function Get-PinnedToolchainRuntime() {
@@ -1469,7 +1470,7 @@ function Build-CMakeProject {
 
       } else {
         Add-KeyValueIfNew $Defines CMAKE_Swift_COMPILER_TARGET $Platform.Triple
-        $SwiftArgs += @("-sdk", (Get-PinnedToolchainSDK))
+        $SwiftArgs += @("-sdk", $(if ($SwiftSDK) { $SwiftSDK } else { Get-PinnedToolchainSDK }))
       }
 
       # Debug Information
@@ -1754,6 +1755,26 @@ function Build-BuildTools([Hashtable] $Platform) {
     }
 }
 
+function Build-EarlySwiftDriver {
+  Build-CMakeProject `
+    -Src $SourceCache\swift-driver `
+    -Bin (Get-ProjectBinaryCache $Platform EarlySwiftDriver) `
+    -Platform $BuildPlatform `
+    -UsePinnedCompilers C,CXX,Swift `
+    -SwiftSDK (Get-PinnedToolchainSDK -OS $BuildPlatform.OS -Identifier "$($BuildPlatform.OS)Experimental") `
+    -BuildTargets default `
+    -Defines @{
+      BUILD_SHARED_LIBS = "NO";
+      BUILD_TESTING = "NO";
+      CMAKE_STATIC_LIBRARY_PREFIX_Swift = "lib";
+      # TODO(compnerd) - enforce dynamic BlocksRuntime and dispatch
+      CMAKE_Swift_FLAGS = @("-static-stdlib", "-Xfrontend", "-use-static-resource-dir", "-Xcc", "-static-libclosure", "-Xcc", "-Ddispatch_STATIC");
+      SWIFT_DRIVER_BUILD_TOOLS = "NO";
+      SQLite3_INCLUDE_DIR = "$SourceCache\swift-toolchain-sqlite\Sources\CSQLite\include";
+      SQLite3_LIBRARY = "$(Get-ProjectBinaryCache $Platform SQLite)\SQLite3.lib";
+    }
+}
+
 function Write-PList {
   [CmdletBinding(PositionalBinding = $false)]
   param
@@ -1823,6 +1844,7 @@ function Get-CompilersDefines([Hashtable] $Platform, [string] $Variant, [switch]
     CLANG_TABLEGEN = (Join-Path -Path $BuildTools -ChildPath "clang-tblgen.exe");
     CLANG_TIDY_CONFUSABLE_CHARS_GEN = (Join-Path -Path $BuildTools -ChildPath "clang-tidy-confusable-chars-gen.exe");
     CMAKE_FIND_PACKAGE_PREFER_CONFIG = "YES";
+    CMAKE_STATIC_LIBRARY_PREFIX_Swift = "lib";
     CMAKE_Swift_FLAGS = $SwiftFlags;
     LibXml2_DIR = "$BinaryCache\$($Platform.Triple)\usr\lib\cmake\libxml2-2.11.5";
     LLDB_LIBXML2_VERSION = "2.11.5";
@@ -3429,6 +3451,8 @@ if (-not $SkipBuild) {
 
   Invoke-BuildStep Build-CMark $BuildPlatform
   Invoke-BuildStep Build-BuildTools $BuildPlatform
+  Invoke-BuildStep Build-SQLite $BuildPlatform
+  Invoke-BuildStep Build-EarlySwiftDriver $BuildPlatform
   if ($IsCrossCompiling) {
     Invoke-BuildStep Build-XML2 $BuildPlatform
     Invoke-BuildStep Build-Compilers $BuildPlatform -Variant "Asserts"