[LibFuzzer] Disable compiling and running the LibFuzzer dataflow sanitizer tests on Apple platforms.

This fixes a broken part of the build on OSX as the dataflow sanitizer is not supported
on OSX yet.

Differential Revision: http://reviews.llvm.org/D20894

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271492 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Fuzzer/test/CMakeLists.txt

@@ -126,7 +126,17 @@ set_target_properties(LLVMFuzzer-Unittest
 ###############################################################################
 
 include_directories(..)
-add_subdirectory(dfsan)
+
+if(APPLE)
+  message(WARNING "Dataflow sanitizer is not supported on Apple platforms."
+    " Building and running LibFuzzer dataflow sanitizer tests is disabled."
+    )
+  set(HAS_DFSAN 0)
+else()
+  set(HAS_DFSAN 1)
+  add_subdirectory(dfsan)
+endif()
+
 add_subdirectory(uninstrumented)
 add_subdirectory(ubsan)
 add_subdirectory(trace-bb)

lib/Fuzzer/test/fuzzer-dfsan.test

@@ -1,3 +1,4 @@
+REQUIRES: dfsan
 CHECK1: BINGO
 CHECK2: BINGO
 CHECK3: BINGO

lib/Fuzzer/test/lit.cfg

@@ -13,3 +13,9 @@ path = os.path.pathsep.join((llvm_tools_dir, config.test_exec_root,
                              config.environment['PATH']))
 config.environment['PATH'] = path
 
+if config.has_dfsan:
+  lit_config.note('dfsan feature available')
+  config.available_features.add('dfsan')
+else:
+  lit_config.note('dfsan feature unavailable')
+

lib/Fuzzer/test/lit.site.cfg.in

@@ -1,3 +1,4 @@
 config.test_exec_root = "@CMAKE_CURRENT_BINARY_DIR@"
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
+config.has_dfsan = True if @HAS_DFSAN@ == 1 else False
 lit_config.load_config(config, "@CMAKE_CURRENT_SOURCE_DIR@/lit.cfg")