[CMake] Revisit PR23539: allow to override SANITIZER_MIN_OSX_VERSION at configure time.

Some users may need to configure Clang/compiler-rt with
-DMACOSX_DEPLOYMENT_TARGET=10.6, as they expect Clang to produce working
(non-sanitized) binaries on 10.6. In this case they would need to
additionally provide -DSANITIZER_MIN_OSX_VERSION=10.7 to mark
that sanitizer runtimes may only be used on 10.7+ (where they are
supported).

llvm-svn: 242363

1 files changed, 12 insertions, 10 deletions

diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
index 66334869a89..646bc3228c4 100644
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -292,16 +292,18 @@ if(APPLE)
   find_darwin_sdk_dir(IOSSIM_SDK_DIR iphonesimulator)
 
   set(SANITIZER_COMMON_SUPPORTED_OS osx)
-  string(REGEX MATCH "-mmacosx-version-min=([.0-9]+)"
-         MACOSX_VERSION_MIN_FLAG "${CMAKE_CXX_FLAGS}")
-  if(MACOSX_VERSION_MIN_FLAG)
-    set(SANITIZER_MIN_OSX_VERSION "${CMAKE_MATCH_1}")
-  elseif(CMAKE_OSX_DEPLOYMENT_TARGET)
-    set(SANITIZER_MIN_OSX_VERSION ${CMAKE_OSX_DEPLOYMENT_TARGET})
-  else()
-    set(SANITIZER_MIN_OSX_VERSION 10.9)
-    if(IOSSIM_SDK_DIR)
-      list(APPEND SANITIZER_COMMON_SUPPORTED_OS iossim)
+  if(NOT SANITIZER_MIN_OSX_VERSION)
+    string(REGEX MATCH "-mmacosx-version-min=([.0-9]+)"
+           MACOSX_VERSION_MIN_FLAG "${CMAKE_CXX_FLAGS}")
+    if(MACOSX_VERSION_MIN_FLAG)
+      set(SANITIZER_MIN_OSX_VERSION "${CMAKE_MATCH_1}")
+    elseif(CMAKE_OSX_DEPLOYMENT_TARGET)
+      set(SANITIZER_MIN_OSX_VERSION ${CMAKE_OSX_DEPLOYMENT_TARGET})
+    else()
+      set(SANITIZER_MIN_OSX_VERSION 10.9)
+      if(IOSSIM_SDK_DIR)
+        list(APPEND SANITIZER_COMMON_SUPPORTED_OS iossim)
+      endif()
     endif()
   endif()
   if(SANITIZER_MIN_OSX_VERSION VERSION_LESS "10.7")