From 8e8055e680d2071e71bd17d055cd5029d7ac5f12 Mon Sep 17 00:00:00 2001
From: Hiroshi Yamauchi <hjyamauchi@gmail.com>
Date: Thu, 16 Oct 2025 15:51:53 -0700
Subject: [PATCH] Add CAS support

---
 utils/build.ps1 | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/utils/build.ps1 b/utils/build.ps1
index 8d49c02efd281..3c4b6585c7364 100644
--- a/utils/build.ps1
+++ b/utils/build.ps1
@@ -158,6 +158,10 @@ param
   [ValidatePattern('^\d+(\.\d+)*$')]
   [string] $SCCacheVersion = "0.10.0",
 
+  # Build with CAS
+  [switch] $EnableCAS = $false,
+  [string] $CASPath = "S:\cas",
+
   # SBoM Support
   [switch] $IncludeSBoM = $false,
   [string] $SyftVersion = "1.29.1",
@@ -560,6 +564,10 @@ if (-not $PinnedBuild) {
 
 $PinnedToolchain = [IO.Path]::GetFileNameWithoutExtension($PinnedBuild)
 
+if ($EnableCAS -and ($UseHostToolchain -or ($PinnedVersion -ne "0.0.0"))) {
+  throw "CAS currently requires using a main-branch pinned toolchain."
+}
+
 $HostPlatform = switch ($HostArchName) {
   "AMD64" { $KnownPlatforms[$HostOS.ToString() + "X64"] }
   "ARM64" { $KnownPlatforms[$HostOS.ToString() + "ARM64"] }
@@ -1569,6 +1577,14 @@ function Build-CMakeProject {
             @("/GS-", "/Gw", "/Gy", "/Oy", "/Oi", "/Zc:inline")
           }
 
+          if ($EnableCAS -and $UsePinnedCompilers.Contains("C")) {
+            $CFLAGS += if ($UseGNUDriver) {
+              @("-fdepscan=inline", "-fdepscan-include-tree", "-Xclang", "-fcas-path", "-Xclang", $CASPath)
+            } else {
+              @("/clang:-fdepscan=inline", "/clang:-fdepscan-include-tree", "-Xclang", "-fcas-path", "-Xclang", $CASPath)
+            }
+          }
+
           if ($DebugInfo) {
             if ($UsePinnedCompilers.Contains("C") -or $UseBuiltCompilers.Contains("C")) {
               if ($CDebugFormat -eq "dwarf") {
@@ -1609,6 +1625,14 @@ function Build-CMakeProject {
             @("/GS-", "/Gw", "/Gy", "/Oy", "/Oi", "/Zc:inline", "/Zc:__cplusplus")
           }
 
+          if ($EnableCAS -and $UsePinnedCompilers.Contains("CXX")) {
+            $CXXFLAGS += if ($UseGNUDriver) {
+              @("-fdepscan=inline", "-fdepscan-include-tree", "-Xclang", "-fcas-path", "-Xclang", $CASPath)
+            } else {
+              @("/clang:-fdepscan=inline", "/clang:-fdepscan-include-tree", "-Xclang", "-fcas-path", "-Xclang", $CASPath)
+            }
+          }
+
           if ($DebugInfo) {
             if ($UsePinnedCompilers.Contains("CXX") -or $UseBuiltCompilers.Contains("CXX")) {
               if ($CDebugFormat -eq "dwarf") {
@@ -2156,6 +2180,12 @@ function Get-CompilersDefines([Hashtable] $Platform, [string] $Variant, [switch]
     $SwiftFlags += @("-use-ld=lld");
   }
 
+  $CMakeStaticLibPrefixSwiftDefine = if ((Get-PinnedToolchainVersion) -eq "0.0.0") {
+    @{ CMAKE_STATIC_LIBRARY_PREFIX_Swift = "lib"; }
+  } else {
+    @{}
+  }
+
   return $TestDefines + $DebugDefines + @{
     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");
@@ -2207,7 +2237,7 @@ function Get-CompilersDefines([Hashtable] $Platform, [string] $Variant, [switch]
     SWIFT_STDLIB_ASSERTIONS = "NO";
     SWIFTSYNTAX_ENABLE_ASSERTIONS = "NO";
     "cmark-gfm_DIR" = "$($Platform.ToolchainInstallRoot)\usr\lib\cmake";
-  }
+  } + $CMakeStaticLibPrefixSwiftDefine
 }
 
 function Build-Compilers([Hashtable] $Platform, [string] $Variant) {