From 5f545b43f9eba29f6a869d9ba70ce0eabc251c7d Mon Sep 17 00:00:00 2001
From: Eric Miotto <1094986+edymtt@users.noreply.github.com>
Date: Thu, 25 Apr 2024 07:51:17 -0700
Subject: [PATCH] CMake: add option to link Swift content from Darwin toolchain

This is needed in specific Apple internal configurations -- as a result
of the limited applicability, this option is not exposed through
`build-script` on purpose.

Addresses rdar://127014753
---
 CMakeLists.txt                                        | 6 ++++++
 cmake/modules/AddSwift.cmake                          | 5 +++++
 tools/SourceKit/cmake/modules/AddSwiftSourceKit.cmake | 6 ++++++
 3 files changed, 17 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f2cfb26c7b00c..c76d78620d40b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -532,6 +532,12 @@ set(SWIFT_DARWIN_STDLIB_INSTALL_NAME_DIR "/usr/lib/swift" CACHE STRING
 set(SWIFT_DARWIN_STDLIB_PRIVATE_INSTALL_NAME_DIR "@rpath" CACHE STRING
     "The directory of the install_name for the private standard library dylibs")
 
+option(SWIFT_ALLOW_LINKING_SWIFT_CONTENT_IN_DARWIN_TOOLCHAIN
+  "Adds search paths for libraries in the toolchain
+   when building Swift programs.
+   This is needed to support Apple internal configurations."
+  FALSE)
+
 set(SWIFT_DARWIN_DEPLOYMENT_VERSION_OSX "10.13" CACHE STRING
     "Minimum deployment target version for OS X")
 
diff --git a/cmake/modules/AddSwift.cmake b/cmake/modules/AddSwift.cmake
index 534110c80202c..266ed77d46214 100644
--- a/cmake/modules/AddSwift.cmake
+++ b/cmake/modules/AddSwift.cmake
@@ -611,6 +611,11 @@ function(_add_swift_runtime_link_flags target relpath_to_lib_dir bootstrapping)
         endif()
       endif()
     endif()
+    if(SWIFT_HOST_VARIANT_SDK IN_LIST SWIFT_DARWIN_PLATFORMS AND SWIFT_ALLOW_LINKING_SWIFT_CONTENT_IN_DARWIN_TOOLCHAIN)
+      get_filename_component(TOOLCHAIN_BIN_DIR ${SWIFT_EXEC_FOR_SWIFT_MODULES} DIRECTORY)
+      get_filename_component(TOOLCHAIN_LIB_DIR "${TOOLCHAIN_BIN_DIR}/../lib/swift/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}" ABSOLUTE)
+      target_link_directories(${target} BEFORE PUBLIC ${TOOLCHAIN_LIB_DIR})
+    endif()
     if(SWIFT_HOST_VARIANT_SDK MATCHES "LINUX|ANDROID|OPENBSD|FREEBSD" AND SWIFT_USE_LINKER STREQUAL "lld")
       target_link_options(${target} PRIVATE "SHELL:-Xlinker -z -Xlinker nostart-stop-gc")
     endif()
diff --git a/tools/SourceKit/cmake/modules/AddSwiftSourceKit.cmake b/tools/SourceKit/cmake/modules/AddSwiftSourceKit.cmake
index 328de29ebb2d8..58baab5b58122 100644
--- a/tools/SourceKit/cmake/modules/AddSwiftSourceKit.cmake
+++ b/tools/SourceKit/cmake/modules/AddSwiftSourceKit.cmake
@@ -173,6 +173,12 @@ function(add_sourcekit_swift_runtime_link_flags target path HAS_SWIFT_MODULES)
         target_link_directories(${target} PUBLIC ${TOOLCHAIN_LIB_DIR})
       endif()
     endif()
+
+    if(SWIFT_HOST_VARIANT_SDK IN_LIST SWIFT_DARWIN_PLATFORMS AND SWIFT_ALLOW_LINKING_SWIFT_CONTENT_IN_DARWIN_TOOLCHAIN)
+      get_filename_component(TOOLCHAIN_BIN_DIR ${SWIFT_EXEC_FOR_SWIFT_MODULES} DIRECTORY)
+      get_filename_component(TOOLCHAIN_LIB_DIR "${TOOLCHAIN_BIN_DIR}/../lib/swift/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}" ABSOLUTE)
+      target_link_directories(${target} BEFORE PUBLIC ${TOOLCHAIN_LIB_DIR})
+    endif()
   endif()
 
   set(RPATH_LIST ${RPATH_LIST} PARENT_SCOPE)