Tests: Cleanup CMake_TEST_XCODE_VERSION code

- Consolidate calls to xcodebuild -version
- Handles cases where CMake_TEST_XCODE_VERSION is 0 to allow
running tests with only	command-line tools.

Tests/BuildDepends/CMakeLists.txt

@@ -47,6 +47,10 @@ if(NOT CMAKE_GENERATOR MATCHES "Visual Studio ([^9]|9[0-9])")
   list(APPEND _cmake_options "-DTEST_MULTI3=1")
 endif()
 
+if (APPLE)
+  list(APPEND _cmake_options "-DCMake_TEST_XCODE_VERSION=${CMake_TEST_XCODE_VERSION}")
+endif()
+
 file(MAKE_DIRECTORY ${BuildDepends_BINARY_DIR}/Project)
 message("Creating Project/foo.cxx")
 write_file(${BuildDepends_BINARY_DIR}/Project/foo.cxx

Tests/BuildDepends/Project/CMakeLists.txt

@@ -1,19 +1,7 @@
 cmake_minimum_required(VERSION 2.6)
 project(testRebuild)
 
-if(APPLE)
-  set(CMake_TEST_XCODE_VERSION 0)
-  if(XCODE_VERSION)
-    set(CMake_TEST_XCODE_VERSION "${XCODE_VERSION}")
-  else()
-    execute_process(
-      COMMAND xcodebuild -version
-      OUTPUT_VARIABLE _version ERROR_VARIABLE _version_err
-      )
-    if(_version MATCHES "^Xcode ([0-9]+(\\.[0-9]+)*)")
-      set(CMake_TEST_XCODE_VERSION "${CMAKE_MATCH_1}")
-    endif()
-  endif()
+if(APPLE AND CMake_TEST_XCODE_VERSION)
   # only use multi-arch if the sysroot exists on this machine
   # Ninja needs -M which could not be used with multiple -arch flags
   if(EXISTS "${CMAKE_OSX_SYSROOT}" AND NOT "${CMAKE_GENERATOR}" MATCHES "Ninja")

Tests/CMakeLists.txt

@@ -299,25 +299,20 @@ if(BUILD_TESTING)
     "Should the tests that use '--build-target package' be run?"
     ON)
   mark_as_advanced(CTEST_TEST_CPACK)
-  set(CTEST_TEST_OSX_ARCH 0)
   set(CMake_TEST_XCODE_VERSION 0)
   if(APPLE)
-    set(CTEST_TEST_OSX_ARCH 1)
     if(XCODE_VERSION)
       set(CMake_TEST_XCODE_VERSION "${XCODE_VERSION}")
     else()
       execute_process(
         COMMAND xcodebuild -version
-        OUTPUT_VARIABLE _version ERROR_VARIABLE _version_err
+        OUTPUT_VARIABLE _version
+        RESULT_VARIABLE _failed
         )
-      if(_version MATCHES "^Xcode ([0-9]+(\\.[0-9]+)*)")
+      if(NOT _failed AND _version MATCHES "^Xcode ([0-9]+(\\.[0-9]+)*)")
         set(CMake_TEST_XCODE_VERSION "${CMAKE_MATCH_1}")
       endif()
     endif()
-    if(NOT CMake_TEST_XCODE_VERSION VERSION_LESS 10)
-      # Since Xcode 10 we do not have two supported architectures for the host.
-      set(CTEST_TEST_OSX_ARCH 0)
-    endif()
     if(CMAKE_OSX_SYSROOT)
       execute_process(
         COMMAND xcodebuild -sdk ${CMAKE_OSX_SYSROOT} -version ProductName
@@ -952,6 +947,8 @@ if(BUILD_TESTING)
     "${CMake_BINARY_DIR}/Tests/BuildDepends"
     ${build_generator_args}
     --build-project BuildDepends
+    --build-options
+    "-DCMake_TEST_XCODE_VERSION=${CMake_TEST_XCODE_VERSION}"
     )
   list(APPEND TEST_BUILD_DIRS "${CMake_BINARY_DIR}/Tests/BuildDepends")