[libc-commits] [libc] [libc] Pass correct system include flag for macOS. (PR #223116)

[via libc-commits]

https://github.com/lntue updated https://github.com/llvm/llvm-project/pull/223116

>From 8bea6cbcadaa22071d17d0b32a9b2dccb859a7ce Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue at google.com>
Date: Fri, 11 Sep 2026 22:42:29 -0400
Subject: [PATCH 1/2] [libc] Pass correct system include flag for macOS.

---
 libc/cmake/modules/LLVMLibCArchitectures.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libc/cmake/modules/LLVMLibCArchitectures.cmake b/libc/cmake/modules/LLVMLibCArchitectures.cmake
index 3149c16f9e2eba..5ad77341edc92e 100644
--- a/libc/cmake/modules/LLVMLibCArchitectures.cmake
+++ b/libc/cmake/modules/LLVMLibCArchitectures.cmake
@@ -250,7 +250,7 @@ if(LIBC_TARGET_OS_IS_DARWIN)
     OUTPUT_STRIP_TRAILING_WHITESPACE
   )
   if(MACOSX_SDK_PATH_RESULT EQUAL 0)
-    list(APPEND LIBC_COMPILE_OPTIONS_DEFAULT "-I" "${MACOSX_SDK_PATH}/usr/include")
+    list(APPEND LIBC_COMPILE_OPTIONS_DEFAULT "-isystem" "${MACOSX_SDK_PATH}/usr/include")
   else()
     message(WARNING "Could not find macOS SDK path. `xcrun --sdk macosx --show-sdk-path` failed.")
   endif()

>From 0246abfbed484120898bef4c2ae6d1ced85c861b Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue at google.com>
Date: Fri, 11 Sep 2026 23:35:54 -0400
Subject: [PATCH 2/2] Use -isysroot instead of -isystem.

---
 libc/cmake/modules/LLVMLibCArchitectures.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libc/cmake/modules/LLVMLibCArchitectures.cmake b/libc/cmake/modules/LLVMLibCArchitectures.cmake
index 5ad77341edc92e..436f863b445e5a 100644
--- a/libc/cmake/modules/LLVMLibCArchitectures.cmake
+++ b/libc/cmake/modules/LLVMLibCArchitectures.cmake
@@ -250,7 +250,7 @@ if(LIBC_TARGET_OS_IS_DARWIN)
     OUTPUT_STRIP_TRAILING_WHITESPACE
   )
   if(MACOSX_SDK_PATH_RESULT EQUAL 0)
-    list(APPEND LIBC_COMPILE_OPTIONS_DEFAULT "-isystem" "${MACOSX_SDK_PATH}/usr/include")
+    list(APPEND LIBC_COMPILE_OPTIONS_DEFAULT "-isysroot" "${MACOSX_SDK_PATH}")
   else()
     message(WARNING "Could not find macOS SDK path. `xcrun --sdk macosx --show-sdk-path` failed.")
   endif()