From 20e13c1af3f65d3ad4616f2c51b2544d843341f1 Mon Sep 17 00:00:00 2001
From: Jeremy Schonfeld <jschonfeld@apple.com>
Date: Thu, 8 Aug 2024 10:51:33 -0700
Subject: [PATCH 1/4] Enable whole-module-optimization in release builds

---
 CMakeLists.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2afb0787e..7da0b48b5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -112,6 +112,13 @@ if(CMAKE_SYSTEM_NAME STREQUAL "WASI")
         "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xcc -D_WASI_EMULATED_MMAN>")
 endif()
 
+# Enable whole module optimization for release builds & incremental for debug builds
+if(POLICY CMP0157)
+    set(CMAKE_Swift_COMPILATION_MODE "$<IF:$<CONFIG:Release>,wholemodule,incremental>")
+else()
+    add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<IF:$<CONFIG:Release>>>:-wmo>)
+endif()
+
 include(GNUInstallDirs)
 include(SwiftFoundationSwiftSupport)
 

From b69c1fae2077b69fc32c58ae04f9bbcfafa778a0 Mon Sep 17 00:00:00 2001
From: Jeremy Schonfeld <jschonfeld@apple.com>
Date: Thu, 8 Aug 2024 11:21:31 -0700
Subject: [PATCH 2/4] Address feedback

---
 CMakeLists.txt | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7da0b48b5..c051b4d7f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,6 +35,13 @@ if(NOT SWIFT_SYSTEM_NAME)
   endif()
 endif()
 
+# Enable whole module optimization for release builds & incremental for debug builds
+if(POLICY CMP0157)
+    set(CMAKE_Swift_COMPILATION_MODE "$<IF:$<CONFIG:Release>,wholemodule,incremental>")
+else()
+    add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<IF:$<CONFIG:Release>>>:-wmo>)
+endif()
+
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
@@ -112,13 +119,6 @@ if(CMAKE_SYSTEM_NAME STREQUAL "WASI")
         "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xcc -D_WASI_EMULATED_MMAN>")
 endif()
 
-# Enable whole module optimization for release builds & incremental for debug builds
-if(POLICY CMP0157)
-    set(CMAKE_Swift_COMPILATION_MODE "$<IF:$<CONFIG:Release>,wholemodule,incremental>")
-else()
-    add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<IF:$<CONFIG:Release>>>:-wmo>)
-endif()
-
 include(GNUInstallDirs)
 include(SwiftFoundationSwiftSupport)
 

From afcb5460085b685e57ca96096e4c86cf0728007b Mon Sep 17 00:00:00 2001
From: Jeremy Schonfeld <jschonfeld@apple.com>
Date: Thu, 8 Aug 2024 15:51:50 -0700
Subject: [PATCH 3/4] Fix build failures

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c051b4d7f..cf4826f06 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,7 +39,7 @@ endif()
 if(POLICY CMP0157)
     set(CMAKE_Swift_COMPILATION_MODE "$<IF:$<CONFIG:Release>,wholemodule,incremental>")
 else()
-    add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<IF:$<CONFIG:Release>>>:-wmo>)
+    add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<CONFIG:Release>>:-wmo>)
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)

From 21aef2ae5f8ac2550416ceae2e0aa28b19ebb4e7 Mon Sep 17 00:00:00 2001
From: Jeremy Schonfeld <jschonfeld@apple.com>
Date: Fri, 9 Aug 2024 09:29:17 -0700
Subject: [PATCH 4/4] Don't enable WMO on Windows

---
 CMakeLists.txt | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cf4826f06..108b65726 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,11 +35,14 @@ if(NOT SWIFT_SYSTEM_NAME)
   endif()
 endif()
 
-# Enable whole module optimization for release builds & incremental for debug builds
-if(POLICY CMP0157)
-    set(CMAKE_Swift_COMPILATION_MODE "$<IF:$<CONFIG:Release>,wholemodule,incremental>")
-else()
-    add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<CONFIG:Release>>:-wmo>)
+# Don't enable WMO on Windows due to linker failures
+if(NOT CMAKE_SYSTEM_NAME STREQUAL Windows)
+    # Enable whole module optimization for release builds & incremental for debug builds
+    if(POLICY CMP0157)
+        set(CMAKE_Swift_COMPILATION_MODE "$<IF:$<CONFIG:Release>,wholemodule,incremental>")
+    else()
+        add_compile_options($<$<AND:$<COMPILE_LANGUAGE:Swift>,$<CONFIG:Release>>:-wmo>)
+    endif()
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)