From d9f97c172f2846c9a322c13c249ac39f5df4dcd7 Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Wed, 1 Oct 2025 12:45:09 -0400
Subject: [PATCH 1/7] Add option to build compilers with LLVM

---
 .github/workflows/build-toolchain.yml |  5 +++--
 .github/workflows/swift-toolchain.yml | 10 ++++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/build-toolchain.yml b/.github/workflows/build-toolchain.yml
index 83f9facee..0f5c5ef61 100644
--- a/.github/workflows/build-toolchain.yml
+++ b/.github/workflows/build-toolchain.yml
@@ -54,8 +54,8 @@ on:
         default: false
         type: boolean
 
-      stable_point:
-        description: 'Use Repo Smart Sync'
+      build_compilers_with_llvm:
+        description: 'Build Windows compilers with clang-cl/lld-link'
         type: boolean
         default: false
         required: false
@@ -628,6 +628,7 @@ jobs:
       compilers_build_runner: ${{ needs.context.outputs[format('windows_{0}_compilers_runner', needs.context.outputs.windows_build_cpu)] }}
       build_android: ${{ inputs.build_android }}
       python_version: ${{ needs.context.outputs.python_version }}
+      build_compilers_with_llvm: ${{ inputs.build_compilers_with_llvm }}
     secrets:
       SYMBOL_SERVER_PAT: ${{ secrets.SYMBOL_SERVER_PAT }}
       CERTIFICATE: ${{ secrets.CERTIFICATE }}
diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index f4d777dab..b48cb2d2c 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -248,6 +248,11 @@ on:
         required: true
         type: string
 
+      build_compilers_with_llvm:
+        required: false
+        type: boolean
+        default: true
+
     secrets:
       SYMBOL_SERVER_PAT:
         required: true
@@ -1087,8 +1092,8 @@ jobs:
           bin-dir: ${{ github.workspace }}/BinaryCache/1
           install-dir: ${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/${{ inputs.swift_version }}+${{ matrix.variant }}/usr
           swift-sdk-path: ${{ steps.setup-context.outputs.sdkroot }}
-          msvc-compilers: '@("C", "CXX")'
-          pinned-compilers: '@("Swift")'
+          msvc-compilers: ${{ inputs.build_compilers_with_llvm && '@()' || '@("C", "CXX")' }}
+          pinned-compilers: ${{ inputs.build_compilers_with_llvm && '@("C", "CXX", "Swift")' || '@("Swift")' }}
           cache-script: ${{ github.workspace }}/SourceCache/swift/cmake/caches/${{ matrix.os }}-${{ matrix.cpu }}.cmake
           cmake-defines: |
             @{
@@ -1140,6 +1145,7 @@ jobs:
               'LLVM_VERSION_SUFFIX' = "";
               'LLVM_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
               'SWIFT_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
+              'CMAKE_Swift_FLAGS' = "${{ inputs.build_compilers_with_llvm && '-use-ld=lld-link' || '' }}";
             }
 
       - name: Build Compiler Distribution

From e11a1f8f9b06ad1e40f9a1d5d622784619e13c82 Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Thu, 2 Oct 2025 14:48:10 -0400
Subject: [PATCH 2/7] More LLD

---
 .github/workflows/swift-toolchain.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index b48cb2d2c..094183ae9 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -1111,6 +1111,7 @@ jobs:
               'LLDB_TABLEGEN' = "${{ github.workspace }}/BinaryCache/0/bin/lldb-tblgen${ExeSuffix}";
               'LLVM_CONFIG_PATH' = "${{ github.workspace }}/BinaryCache/0/bin/llvm-config${ExeSuffix}";
               'LLVM_ENABLE_ASSERTIONS' = ${{ matrix.variant == 'Asserts' && '"YES"' || '"NO"' }};
+              'LLVM_ENABLE_LLD' = "${{ inputs.build_compilers_with_llvm && 'YES' || 'NO' }}";
               'LLVM_EXTERNAL_SWIFT_SOURCE_DIR' = "${{ github.workspace }}/SourceCache/swift";
               'LLVM_HOST_TRIPLE' = "${{ matrix.triple }}";
               'LLVM_NATIVE_TOOL_DIR' = "${{ github.workspace }}/BinaryCache/0/bin";
@@ -1145,7 +1146,7 @@ jobs:
               'LLVM_VERSION_SUFFIX' = "";
               'LLVM_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
               'SWIFT_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
-              'CMAKE_Swift_FLAGS' = "${{ inputs.build_compilers_with_llvm && '-use-ld=lld-link' || '' }}";
+              'CMAKE_Swift_FLAGS' = "${{ inputs.build_compilers_with_llvm && '-use-ld=lld' || '' }}";
             }
 
       - name: Build Compiler Distribution

From 76e2557ba6671c555bc12c16f2f671b9601bb95d Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Tue, 7 Oct 2025 18:01:51 -0400
Subject: [PATCH 3/7] default: false

---
 .github/workflows/swift-toolchain.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index 094183ae9..e434d3270 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -251,7 +251,7 @@ on:
       build_compilers_with_llvm:
         required: false
         type: boolean
-        default: true
+        default: false
 
     secrets:
       SYMBOL_SERVER_PAT:

From 41984b87a7ccb5a777683c482b42c78b57eaf983 Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Tue, 7 Oct 2025 19:14:45 -0400
Subject: [PATCH 4/7] Rename, use LLVM for everything if used

---
 .github/workflows/build-toolchain.yml |  4 +--
 .github/workflows/swift-toolchain.yml | 40 +++++++++++++++++----------
 2 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/.github/workflows/build-toolchain.yml b/.github/workflows/build-toolchain.yml
index 0f5c5ef61..83219be9c 100644
--- a/.github/workflows/build-toolchain.yml
+++ b/.github/workflows/build-toolchain.yml
@@ -54,8 +54,8 @@ on:
         default: false
         type: boolean
 
-      build_compilers_with_llvm:
-        description: 'Build Windows compilers with clang-cl/lld-link'
+      llvm_clang:
+        description: 'Build with clang-cl/lld-link'
         type: boolean
         default: false
         required: false
diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index e434d3270..b33703ff4 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -248,7 +248,7 @@ on:
         required: true
         type: string
 
-      build_compilers_with_llvm:
+      llvm_clang:
         required: false
         type: boolean
         default: false
@@ -355,7 +355,8 @@ jobs:
           install-dir: ${{ github.workspace }}/BuildRoot/Library/sqlite-${{ inputs.swift_toolchain_sqlite_version }}/usr
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
-          msvc-compilers: '@("C")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
@@ -439,7 +440,8 @@ jobs:
           arch: ${{ inputs.build_arch }}
           src-dir: ${{ github.workspace }}/SourceCache/ds2/Tools/RegsGen2
           bin-dir: ${{ github.workspace }}/BinaryCache/RegsGen2
-          msvc-compilers: '@("C", "CXX")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX")' || '@()' }}
           cache-script: ${{ github.workspace }}/SourceCache/ds2/cmake/caches/MSVCWarnings.cmake
       - name: Build RegsGen2
         if: inputs.build_android
@@ -637,7 +639,8 @@ jobs:
           src-dir: ${{ github.workspace }}/SourceCache/cmark-gfm
           bin-dir: ${{ github.workspace }}/BinaryCache/cmark-gfm-${{ inputs.swift_cmark_version }}
           install-dir: ${{ github.workspace }}/BuildRoot/Library/cmark-gfm-${{ inputs.swift_cmark_version }}/usr
-          msvc-compilers: '@("C", "CXX")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX")' || '@()' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "YES";
@@ -730,7 +733,8 @@ jobs:
           arch: ${{ matrix.arch }}
           src-dir: ${{ github.workspace }}/SourceCache/llvm-project/llvm
           bin-dir: ${{ github.workspace }}/BinaryCache/0
-          msvc-compilers: '@("ASM_MASM", "C", "CXX")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("ASM_MASM", "C", "CXX")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("ASM_MASM", "C", "CXX")' || '@()' }}
           cmake-defines: |
             @{
               'CMAKE_CROSSCOMPILING' = "NO";
@@ -1092,8 +1096,8 @@ jobs:
           bin-dir: ${{ github.workspace }}/BinaryCache/1
           install-dir: ${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/${{ inputs.swift_version }}+${{ matrix.variant }}/usr
           swift-sdk-path: ${{ steps.setup-context.outputs.sdkroot }}
-          msvc-compilers: ${{ inputs.build_compilers_with_llvm && '@()' || '@("C", "CXX")' }}
-          pinned-compilers: ${{ inputs.build_compilers_with_llvm && '@("C", "CXX", "Swift")' || '@("Swift")' }}
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX", "Swift")' || '@("Swift")' }}
           cache-script: ${{ github.workspace }}/SourceCache/swift/cmake/caches/${{ matrix.os }}-${{ matrix.cpu }}.cmake
           cmake-defines: |
             @{
@@ -1111,7 +1115,7 @@ jobs:
               'LLDB_TABLEGEN' = "${{ github.workspace }}/BinaryCache/0/bin/lldb-tblgen${ExeSuffix}";
               'LLVM_CONFIG_PATH' = "${{ github.workspace }}/BinaryCache/0/bin/llvm-config${ExeSuffix}";
               'LLVM_ENABLE_ASSERTIONS' = ${{ matrix.variant == 'Asserts' && '"YES"' || '"NO"' }};
-              'LLVM_ENABLE_LLD' = "${{ inputs.build_compilers_with_llvm && 'YES' || 'NO' }}";
+              'LLVM_ENABLE_LLD' = "${{ inputs.llvm_clang && 'YES' || 'NO' }}";
               'LLVM_EXTERNAL_SWIFT_SOURCE_DIR' = "${{ github.workspace }}/SourceCache/swift";
               'LLVM_HOST_TRIPLE' = "${{ matrix.triple }}";
               'LLVM_NATIVE_TOOL_DIR' = "${{ github.workspace }}/BinaryCache/0/bin";
@@ -1146,7 +1150,7 @@ jobs:
               'LLVM_VERSION_SUFFIX' = "";
               'LLVM_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
               'SWIFT_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
-              'CMAKE_Swift_FLAGS' = "${{ inputs.build_compilers_with_llvm && '-use-ld=lld' || '' }}";
+              'CMAKE_Swift_FLAGS' = "${{ inputs.llvm_clang && '-use-ld=lld' || '' }}";
             }
 
       - name: Build Compiler Distribution
@@ -1315,7 +1319,8 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: '@("C")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
@@ -1497,7 +1502,8 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: '@("C")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
@@ -1670,7 +1676,8 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: '@("C", "CXX")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX")' || '@()' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
@@ -1802,7 +1809,8 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: '@("ASM_MASM", "C", "CXX")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("ASM_MASM", "C", "CXX")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("ASM_MASM", "C", "CXX")' || '@()' }}
           cmake-defines: |
             @{
               'LLVM_ENABLE_ASSERTIONS' = "YES";
@@ -3713,7 +3721,8 @@ jobs:
           bin-dir: ${{ github.workspace }}/BinaryCache/swift-format
           install-dir: ${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/${{ inputs.swift_version }}+Asserts/usr
           swift-sdk-path: ${{ github.workspace }}/BinaryCache/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk
-          msvc-compilers: '@("C")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
           built-compilers: '@("Swift")'
           cmake-defines: |
             @{
@@ -3740,7 +3749,8 @@ jobs:
           src-dir: ${{ github.workspace }}/SourceCache/swift-lmdb
           bin-dir: ${{ github.workspace }}/BinaryCache/swift-lmdb
           swift-sdk-path: ${{ github.workspace }}/BinaryCache/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk
-          msvc-compilers: '@("C")'
+          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
+          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
       - name: Build swift-lmdb
         run: cmake --build ${{ github.workspace }}/BinaryCache/swift-lmdb
 

From e25bc903e402fd49c0137cc6ce7219139c04f469 Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Tue, 7 Oct 2025 19:29:21 -0400
Subject: [PATCH 5/7] Fix

---
 .github/workflows/build-toolchain.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build-toolchain.yml b/.github/workflows/build-toolchain.yml
index 83219be9c..39c248e86 100644
--- a/.github/workflows/build-toolchain.yml
+++ b/.github/workflows/build-toolchain.yml
@@ -628,7 +628,7 @@ jobs:
       compilers_build_runner: ${{ needs.context.outputs[format('windows_{0}_compilers_runner', needs.context.outputs.windows_build_cpu)] }}
       build_android: ${{ inputs.build_android }}
       python_version: ${{ needs.context.outputs.python_version }}
-      build_compilers_with_llvm: ${{ inputs.build_compilers_with_llvm }}
+      llvm_clang: ${{ inputs.llvm_clang }}
     secrets:
       SYMBOL_SERVER_PAT: ${{ secrets.SYMBOL_SERVER_PAT }}
       CERTIFICATE: ${{ secrets.CERTIFICATE }}

From fec01cf90b0971147759907d05a45e5546ed2b4b Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Thu, 9 Oct 2025 14:11:07 -0400
Subject: [PATCH 6/7] LLD everywhere and invert name

---
 .github/workflows/build-toolchain.yml |  8 +--
 .github/workflows/swift-toolchain.yml | 75 +++++++++++++++++----------
 2 files changed, 53 insertions(+), 30 deletions(-)

diff --git a/.github/workflows/build-toolchain.yml b/.github/workflows/build-toolchain.yml
index 39c248e86..7d82b805f 100644
--- a/.github/workflows/build-toolchain.yml
+++ b/.github/workflows/build-toolchain.yml
@@ -54,10 +54,10 @@ on:
         default: false
         type: boolean
 
-      llvm_clang:
-        description: 'Build with clang-cl/lld-link'
+      use_host_toolchain:
+        description: 'Use host toolchain (MSVC) instead of clang-cl/lld-link'
         type: boolean
-        default: false
+        default: true
         required: false
 
   workflow_call:
@@ -628,7 +628,7 @@ jobs:
       compilers_build_runner: ${{ needs.context.outputs[format('windows_{0}_compilers_runner', needs.context.outputs.windows_build_cpu)] }}
       build_android: ${{ inputs.build_android }}
       python_version: ${{ needs.context.outputs.python_version }}
-      llvm_clang: ${{ inputs.llvm_clang }}
+      use_host_toolchain: ${{ inputs.use_host_toolchain }}
     secrets:
       SYMBOL_SERVER_PAT: ${{ secrets.SYMBOL_SERVER_PAT }}
       CERTIFICATE: ${{ secrets.CERTIFICATE }}
diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index b33703ff4..f998cdae5 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -248,10 +248,10 @@ on:
         required: true
         type: string
 
-      llvm_clang:
+      use_host_toolchain:
         required: false
         type: boolean
-        default: false
+        default: true
 
     secrets:
       SYMBOL_SERVER_PAT:
@@ -355,11 +355,12 @@ jobs:
           install-dir: ${{ github.workspace }}/BuildRoot/Library/sqlite-${{ inputs.swift_toolchain_sqlite_version }}/usr
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C")' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build SQLite
         run: cmake --build ${{ github.workspace }}/BinaryCache/sqlite-${{ inputs.swift_toolchain_sqlite_version }}
@@ -440,9 +441,14 @@ jobs:
           arch: ${{ inputs.build_arch }}
           src-dir: ${{ github.workspace }}/SourceCache/ds2/Tools/RegsGen2
           bin-dir: ${{ github.workspace }}/BinaryCache/RegsGen2
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C", "CXX")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C", "CXX")' }}
           cache-script: ${{ github.workspace }}/SourceCache/ds2/cmake/caches/MSVCWarnings.cmake
+          cmake-defines: |
+            @{
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_CXX_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+            }
       - name: Build RegsGen2
         if: inputs.build_android
         run: cmake --build ${{ github.workspace }}/BinaryCache/RegsGen2 --config Release
@@ -639,13 +645,15 @@ jobs:
           src-dir: ${{ github.workspace }}/SourceCache/cmark-gfm
           bin-dir: ${{ github.workspace }}/BinaryCache/cmark-gfm-${{ inputs.swift_cmark_version }}
           install-dir: ${{ github.workspace }}/BuildRoot/Library/cmark-gfm-${{ inputs.swift_cmark_version }}/usr
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C", "CXX")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C", "CXX")' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "YES";
               'BUILD_TESTING' = "NO";
               'CMAKE_INSTALL_SYSTEM_RUNTIME_LIBS_SKIP' = "YES";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_CXX_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build cmark-gfm
         run: cmake --build ${{ github.workspace }}/BinaryCache/cmark-gfm-${{ inputs.swift_cmark_version }}
@@ -733,8 +741,8 @@ jobs:
           arch: ${{ matrix.arch }}
           src-dir: ${{ github.workspace }}/SourceCache/llvm-project/llvm
           bin-dir: ${{ github.workspace }}/BinaryCache/0
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("ASM_MASM", "C", "CXX")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("ASM_MASM", "C", "CXX")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("ASM_MASM", "C", "CXX")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("ASM_MASM", "C", "CXX")' }}
           cmake-defines: |
             @{
               'CMAKE_CROSSCOMPILING' = "NO";
@@ -764,6 +772,8 @@ jobs:
               'SWIFT_INCLUDE_DOCS' = "NO";
               'SWIFT_INCLUDE_TESTS' = "NO";
               'cmark-gfm_DIR' = "${{ github.workspace }}/BuildRoot/Library/cmark-gfm-${{ inputs.swift_cmark_version }}/usr/lib/cmake";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_CXX_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build llvm-tblgen
         run: cmake --build ${{ github.workspace }}/BinaryCache/0 --target llvm-tblgen
@@ -1096,8 +1106,8 @@ jobs:
           bin-dir: ${{ github.workspace }}/BinaryCache/1
           install-dir: ${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/${{ inputs.swift_version }}+${{ matrix.variant }}/usr
           swift-sdk-path: ${{ steps.setup-context.outputs.sdkroot }}
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX", "Swift")' || '@("Swift")' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C", "CXX")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@("Swift")' || '@("C", "CXX", "Swift")' }}
           cache-script: ${{ github.workspace }}/SourceCache/swift/cmake/caches/${{ matrix.os }}-${{ matrix.cpu }}.cmake
           cmake-defines: |
             @{
@@ -1115,7 +1125,7 @@ jobs:
               'LLDB_TABLEGEN' = "${{ github.workspace }}/BinaryCache/0/bin/lldb-tblgen${ExeSuffix}";
               'LLVM_CONFIG_PATH' = "${{ github.workspace }}/BinaryCache/0/bin/llvm-config${ExeSuffix}";
               'LLVM_ENABLE_ASSERTIONS' = ${{ matrix.variant == 'Asserts' && '"YES"' || '"NO"' }};
-              'LLVM_ENABLE_LLD' = "${{ inputs.llvm_clang && 'YES' || 'NO' }}";
+              'LLVM_ENABLE_LLD' = "${{ inputs.use_host_toolchain && 'NO' || 'YES' }}";
               'LLVM_EXTERNAL_SWIFT_SOURCE_DIR' = "${{ github.workspace }}/SourceCache/swift";
               'LLVM_HOST_TRIPLE' = "${{ matrix.triple }}";
               'LLVM_NATIVE_TOOL_DIR' = "${{ github.workspace }}/BinaryCache/0/bin";
@@ -1150,7 +1160,9 @@ jobs:
               'LLVM_VERSION_SUFFIX' = "";
               'LLVM_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
               'SWIFT_PARALLEL_LINK_JOBS' = "${{ steps.setup-context.outputs.link-jobs }}";
-              'CMAKE_Swift_FLAGS' = "${{ inputs.llvm_clang && '-use-ld=lld' || '' }}";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_CXX_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_Swift_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-use-ld=lld' }}";
             }
 
       - name: Build Compiler Distribution
@@ -1319,12 +1331,13 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C")' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
               'CMAKE_POSITION_INDEPENDENT_CODE' = "YES";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build zlib
         run: cmake --build ${{ github.workspace }}/BinaryCache/zlib-${{ inputs.zlib_version }}
@@ -1502,8 +1515,8 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C")' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
@@ -1593,6 +1606,7 @@ jobs:
               'USE_WIN32_LDAP' = "NO";
               'ZLIB_ROOT' = "${{ github.workspace }}/BuildRoot/Library/zlib-${{ inputs.zlib_version }}/usr";
               'ZLIB_LIBRARY' = "${{ github.workspace }}/BuildRoot/Library/zlib-${{ inputs.zlib_version }}/usr/lib/zlibstatic.lib";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build curl
         run: cmake --build ${{ github.workspace }}/BinaryCache/curl-${{ inputs.curl_version }}
@@ -1676,8 +1690,8 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C", "CXX")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C", "CXX")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C", "CXX")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C", "CXX")' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
@@ -1689,6 +1703,8 @@ jobs:
               'LIBXML2_WITH_TESTS' = "NO";
               'LIBXML2_WITH_THREADS' = "YES";
               'LIBXML2_WITH_ZLIB' = "NO";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_CXX_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build libxml2
         run: cmake --build ${{ github.workspace }}/BinaryCache/libxml2-${{ inputs.libxml2_version }}
@@ -1809,12 +1825,14 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("ASM_MASM", "C", "CXX")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("ASM_MASM", "C", "CXX")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("ASM_MASM", "C", "CXX")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("ASM_MASM", "C", "CXX")' }}
           cmake-defines: |
             @{
               'LLVM_ENABLE_ASSERTIONS' = "YES";
               'LLVM_HOST_TRIPLE' = "${{ matrix.triple }}";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+              'CMAKE_CXX_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
              }
 
       - name: Configure Swift Standard Library
@@ -3721,8 +3739,8 @@ jobs:
           bin-dir: ${{ github.workspace }}/BinaryCache/swift-format
           install-dir: ${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/${{ inputs.swift_version }}+Asserts/usr
           swift-sdk-path: ${{ github.workspace }}/BinaryCache/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C")' }}
           built-compilers: '@("Swift")'
           cmake-defines: |
             @{
@@ -3731,6 +3749,7 @@ jobs:
               'SwiftMarkdown_DIR' = "${{ github.workspace }}/BinaryCache/swift-markdown/cmake/modules";
               'SwiftSyntax_DIR' = "${{ github.workspace }}/BinaryCache/swift-syntax/cmake/modules";
               'cmark-gfm_DIR' = "${{ github.workspace }}/BinaryCache/Library/cmark-gfm-${{ inputs.swift_cmark_version }}/usr/lib/cmake";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build swift-format
         run: cmake --build ${{ github.workspace }}/BinaryCache/swift-format
@@ -3749,8 +3768,12 @@ jobs:
           src-dir: ${{ github.workspace }}/SourceCache/swift-lmdb
           bin-dir: ${{ github.workspace }}/BinaryCache/swift-lmdb
           swift-sdk-path: ${{ github.workspace }}/BinaryCache/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk
-          msvc-compilers: ${{ inputs.llvm_clang && '@()' || '@("C")' }}
-          pinned-compilers: ${{ inputs.llvm_clang && '@("C")' || '@()' }}
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C")' }}
+          cmake-defines: |
+            @{
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
+            }
       - name: Build swift-lmdb
         run: cmake --build ${{ github.workspace }}/BinaryCache/swift-lmdb
 

From 7eb662bc36a316dc5cc3c5ba9aef55858ec8dcca Mon Sep 17 00:00:00 2001
From: Leonard Grey <leonard@leonardgrey.com>
Date: Fri, 10 Oct 2025 10:18:06 -0400
Subject: [PATCH 7/7] Rebase and add Brotli

---
 .github/workflows/swift-toolchain.yml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index f998cdae5..c2a15a928 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -1421,11 +1421,13 @@ jobs:
           android-api-level: ${{ inputs.ANDROID_API_LEVEL }}
           android-clang-version: ${{ inputs.ANDROID_CLANG_VERSION }}
           ndk-path: ${{ steps.setup-ndk.outputs.ndk-path }}
-          msvc-compilers: '@("C")'
+          msvc-compilers: ${{ inputs.use_host_toolchain && '@("C")' || '@()' }}
+          pinned-compilers: ${{ inputs.use_host_toolchain && '@()' || '@("C")' }}
           cmake-defines: |
             @{
               'BUILD_SHARED_LIBS' = "NO";
               'CMAKE_POSITION_INDEPENDENT_CODE' = "YES";
+              'CMAKE_C_FLAGS' = "${{ inputs.use_host_toolchain && '' || '-fuse-ld=lld' }}";
             }
       - name: Build brotli
         run: cmake --build ${{ github.workspace }}/BinaryCache/brotli-${{ inputs.brotli_version }}