Get the linker version and pass the it to compiler-rt tests on Darwin.

clang/CMakeLists.txt

@@ -15,6 +15,7 @@ endif()
 
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GetDarwinLinkerVersion)
 
 if(CLANG_BUILT_STANDALONE)
   set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to conform to")
@@ -346,20 +347,7 @@ endif ()
 # Determine HOST_LINK_VERSION on Darwin.
 set(HOST_LINK_VERSION)
 if (APPLE AND NOT CMAKE_LINKER MATCHES ".*lld.*")
-  set(LD_V_OUTPUT)
-  execute_process(
-    COMMAND sh -c "${CMAKE_LINKER} -v 2>&1 | head -1"
-    RESULT_VARIABLE HAD_ERROR
-    OUTPUT_VARIABLE LD_V_OUTPUT
-  )
-  if (HAD_ERROR)
-    message(FATAL_ERROR "${CMAKE_LINKER} failed with status ${HAD_ERROR}")
-  endif()
-  if ("${LD_V_OUTPUT}" MATCHES ".*ld64-([0-9.]+).*")
-    string(REGEX REPLACE ".*ld64-([0-9.]+).*" "\\1" HOST_LINK_VERSION ${LD_V_OUTPUT})
-  elseif ("${LD_V_OUTPUT}" MATCHES "[^0-9]*([0-9.]+).*")
-    string(REGEX REPLACE "[^0-9]*([0-9.]+).*" "\\1" HOST_LINK_VERSION ${LD_V_OUTPUT})
-  endif()
+  get_darwin_linker_version(HOST_LINK_VERSION)
   message(STATUS "Host linker version: ${HOST_LINK_VERSION}")
 endif()
 

cmake/Modules/GetDarwinLinkerVersion.cmake

@@ -0,0 +1,19 @@
+# Get the linker version on Darwin
+function(get_darwin_linker_version variable)
+  set(LINK_VERSION)
+  set(LD_V_OUTPUT)
+  execute_process(
+    COMMAND sh -c "${CMAKE_LINKER} -v 2>&1 | head -1"
+    RESULT_VARIABLE HAD_ERROR
+    OUTPUT_VARIABLE LD_V_OUTPUT
+    )
+  if (HAD_ERROR)
+    message(FATAL_ERROR "${CMAKE_LINKER} failed with status ${HAD_ERROR}")
+  endif()
+  if ("${LD_V_OUTPUT}" MATCHES ".*ld64-([0-9.]+).*")
+    string(REGEX REPLACE ".*ld64-([0-9.]+).*" "\\1" LINK_VERSION ${LD_V_OUTPUT})
+  elseif ("${LD_V_OUTPUT}" MATCHES "[^0-9]*([0-9.]+).*")
+    string(REGEX REPLACE "[^0-9]*([0-9.]+).*" "\\1" LINK_VERSION ${LD_V_OUTPUT})
+  endif()
+  set(${variable} ${LINK_VERSION} PARENT_SCOPE)
+endfunction()

compiler-rt/CMakeLists.txt

@@ -36,6 +36,7 @@ include(SetPlatformToolchainTools)
 include(base-config-ix)
 include(CompilerRTUtils)
 include(CMakeDependentOption)
+include(GetDarwinLinkerVersion)
 
 option(COMPILER_RT_BUILD_BUILTINS "Build builtins" ON)
 mark_as_advanced(COMPILER_RT_BUILD_BUILTINS)
@@ -444,6 +445,15 @@ else()
   set(SANITIZER_USE_SYMBOLS FALSE)
 endif()
 
+# Get the linker version while configuring compiler-rt and explicitly pass it
+# in cflags during testing. This fixes the compiler/linker version mismatch
+# issue when running a clang built with a newer Xcode in an older Xcode
+set(COMPILER_RT_DARWIN_LINKER_VERSION)
+if (APPLE AND NOT CMAKE_LINKER MATCHES ".*lld.*")
+  get_darwin_linker_version(COMPILER_RT_DARWIN_LINKER_VERSION)
+  message(STATUS "Host linker version: ${COMPILER_RT_DARWIN_LINKER_VERSION}")
+endif()
+
 # Build sanitizer runtimes with debug info.
 if(MSVC)
   # Use /Z7 instead of /Zi for the asan runtime. This avoids the LNK4099

compiler-rt/test/lit.common.cfg.py

@@ -882,6 +882,10 @@ def is_windows_lto_supported():
 elif config.use_lld and (not config.has_lld):
     config.unsupported = True
 
+if config.host_os == "Darwin":
+    if getattr(config, "darwin_linker_version", None):
+        extra_cflags += ["-mlinker-version=" + config.darwin_linker_version]
+
 # Append any extra flags passed in lit_config
 append_target_cflags = lit_config.params.get("append_target_cflags", None)
 if append_target_cflags:

compiler-rt/test/lit.common.configured.in

@@ -51,6 +51,7 @@ set_default("expensive_checks", @LLVM_ENABLE_EXPENSIVE_CHECKS_PYBOOL@)
 set_default("test_standalone_build_libs", @COMPILER_RT_TEST_STANDALONE_BUILD_LIBS_PYBOOL@)
 set_default("has_compiler_rt_libatomic", @COMPILER_RT_BUILD_STANDALONE_LIBATOMIC_PYBOOL@)
 set_default("aarch64_sme", @COMPILER_RT_HAS_AARCH64_SME_PYBOOL@)
+set_default("darwin_linker_version", "@COMPILER_RT_DARWIN_LINKER_VERSION@")
 # True iff the test suite supports ignoring the test compiler's runtime library path
 # and using `config.compiler_rt_libdir` instead. This only matters when the runtime
 # library paths differ.