[llvm] [libcxx] passthrough OSX_DEPLOYMENT_TARGET for runtimes (PR #126668)

[Benjamin Schaaf via llvm-commits]

https://github.com/BenjaminSchaaf created https://github.com/llvm/llvm-project/pull/126668

This makes it possible to use libcxx and libunwind on version of macOS older than the build environment. Without this change there are missing symbols.

This is already done for compiler-rt in clang/runtime/CMakeLists.txt.

>From 22c027ca99d083d47c63b73cec40debf48bb72aa Mon Sep 17 00:00:00 2001
From: Benjamin Schaaf <bschaaf at sublimetext.com>
Date: Tue, 11 Feb 2025 16:28:03 +1100
Subject: [PATCH] [libcxx] passthrough OSX_DEPLOYMENT_TARGET for runtimes

This makes it possible to use libcxx and libunwind on version of macOS
older than the build environment. Without this change there are missing
symbols.

This is already done for compiler-rt in clang/runtime/CMakeLists.txt.
---
 llvm/runtimes/CMakeLists.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
index 70e85c123e41273..4745404ea22b55f 100644
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -271,6 +271,7 @@ function(runtime_default_target)
                                       -DCMAKE_C_COMPILER_WORKS=ON
                                       -DCMAKE_CXX_COMPILER_WORKS=ON
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
+                                      -DCMAKE_OSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}
                                       ${COMMON_CMAKE_ARGS}
                                       ${RUNTIMES_CMAKE_ARGS}
                                       ${ARG_CMAKE_ARGS}
@@ -407,6 +408,7 @@ function(runtime_register_target name)
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
                                       -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
                                       -DLLVM_RUNTIMES_TARGET=${name}
+                                      -DCMAKE_OSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}
                                       ${COMMON_CMAKE_ARGS}
                                       ${${name}_extra_args}
                            EXTRA_TARGETS ${${name}_extra_targets}