From 13c213b560638f10664590d91a93c952190b848c Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Thu, 4 Feb 2021 09:13:32 -0800
Subject: [PATCH] build: allow using a build tree of dispatch, Foundation

When building swift-crypto from source for a toolchain build, it is
convenient to build it without building up a toolchain image.  This
additional knob allows for building swift-crypto with the build
artifacts of previous builds, allowing building up a toolchain image
while chaining multiple builds together.
---
 CMakeLists.txt                | 5 +++++
 Sources/Crypto/CMakeLists.txt | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab3cc98a6..881a872c1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -37,5 +37,10 @@ if(BUILD_SHARED_LIBS)
   set(CMAKE_POSITION_INDEPENDENT_CODE YES)
 endif()
 
+if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
+  find_package(dispatch CONFIG)
+  find_package(Foundation CONFIG)
+endif()
+
 add_subdirectory(Sources)
 add_subdirectory(cmake/modules)
diff --git a/Sources/Crypto/CMakeLists.txt b/Sources/Crypto/CMakeLists.txt
index 683528f1f..be6451ec0 100644
--- a/Sources/Crypto/CMakeLists.txt
+++ b/Sources/Crypto/CMakeLists.txt
@@ -80,6 +80,8 @@ target_include_directories(Crypto PRIVATE
   $<TARGET_PROPERTY:CCryptoBoringSSL,INCLUDE_DIRECTORIES>
   $<TARGET_PROPERTY:CCryptoBoringSSLShims,INCLUDE_DIRECTORIES>)
 target_link_libraries(Crypto PUBLIC
+  $<$<NOT:$<PLATFORM_ID:Darwin>>:dispatch>
+  $<$<NOT:$<PLATFORM_ID:Darwin>>:Foundation>
   CCryptoBoringSSL
   CCryptoBoringSSLShims)
 set_target_properties(Crypto PROPERTIES