[compiler-rt] [compiler-rt] [CMake] Skip find_darwin_sdk_dir on disabled platforms (PR #163591)

[Andrew Haberlandt via llvm-commits]

https://github.com/ndrewh created https://github.com/llvm/llvm-project/pull/163591

find_darwin_sdk_dir can be slow, especially if xcrun does not immediately find the corresponding SDK (i.e. because it is missing).

This skips those checks if the user has already set the corresponding CMake variable to disable the platform anyway.

>From 7fc90dcd96499ffc95783d8deada35127af37427 Mon Sep 17 00:00:00 2001
From: Andrew Haberlandt <ahaberlandt at apple.com>
Date: Wed, 15 Oct 2025 09:40:31 -0700
Subject: [PATCH] [compiler-rt] [CMake] Skip find_darwin_sdk_dir on disabled
 platforms

find_darwin_sdk_dir can be slow, especially if xcrun does not
immediately find the corresponding SDK (i.e. because it is missing).

This skips those checks if the user has already set the corresponding
CMake variable to disable the platform anyway.
---
 compiler-rt/cmake/builtin-config-ix.cmake | 24 +++++++++++++++--------
 compiler-rt/cmake/config-ix.cmake         | 18 +++++++++++------
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/compiler-rt/cmake/builtin-config-ix.cmake b/compiler-rt/cmake/builtin-config-ix.cmake
index b86bb1bca7cda..eaff8135cff45 100644
--- a/compiler-rt/cmake/builtin-config-ix.cmake
+++ b/compiler-rt/cmake/builtin-config-ix.cmake
@@ -117,14 +117,22 @@ include(CompilerRTDarwinUtils)
 if(APPLE)
 
   find_darwin_sdk_dir(DARWIN_osx_SYSROOT macosx)
-  find_darwin_sdk_dir(DARWIN_iossim_SYSROOT iphonesimulator)
-  find_darwin_sdk_dir(DARWIN_ios_SYSROOT iphoneos)
-  find_darwin_sdk_dir(DARWIN_watchossim_SYSROOT watchsimulator)
-  find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
-  find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
-  find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
-  find_darwin_sdk_dir(DARWIN_xrossim_SYSROOT xrsimulator)
-  find_darwin_sdk_dir(DARWIN_xros_SYSROOT xros)
+  if(COMPILER_RT_ENABLE_IOS)
+    find_darwin_sdk_dir(DARWIN_iossim_SYSROOT iphonesimulator)
+    find_darwin_sdk_dir(DARWIN_ios_SYSROOT iphoneos)
+  endif()
+  if(COMPILER_RT_ENABLE_WATCHOS)
+    find_darwin_sdk_dir(DARWIN_watchossim_SYSROOT watchsimulator)
+    find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
+  endif()
+  if(COMPILER_RT_ENABLE_TVOS)
+    find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
+    find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
+  endif()
+  if(COMPILER_RT_ENABLE_XROS)
+    find_darwin_sdk_dir(DARWIN_xrossim_SYSROOT xrsimulator)
+    find_darwin_sdk_dir(DARWIN_xros_SYSROOT xros)
+  endif()
 
   # Get supported architecture from SDKSettings.
   function(sdk_has_arch_support sdk_path os arch has_support)
diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index 67db4383ec3dc..8dfbdecbd6b97 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -408,12 +408,18 @@ if(APPLE)
   include(CompilerRTDarwinUtils)
 
   find_darwin_sdk_dir(DARWIN_osx_SYSROOT macosx)
-  find_darwin_sdk_dir(DARWIN_iossim_SYSROOT iphonesimulator)
-  find_darwin_sdk_dir(DARWIN_ios_SYSROOT iphoneos)
-  find_darwin_sdk_dir(DARWIN_watchossim_SYSROOT watchsimulator)
-  find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
-  find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
-  find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
+  if(COMPILER_RT_ENABLE_IOS)
+    find_darwin_sdk_dir(DARWIN_iossim_SYSROOT iphonesimulator)
+    find_darwin_sdk_dir(DARWIN_ios_SYSROOT iphoneos)
+  endif()
+  if(COMPILER_RT_ENABLE_WATCHOS)
+    find_darwin_sdk_dir(DARWIN_watchossim_SYSROOT watchsimulator)
+    find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
+  endif()
+  if(COMPILER_RT_ENABLE_TVOS)
+    find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
+    find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
+  endif()
 
   if(NOT DARWIN_osx_SYSROOT)
     message(WARNING "Could not determine OS X sysroot, trying /usr/include")