[TSan] Build TSan-instrumented version of libcxx and use it in lit tests.

TSan can produce false positives in code that uses C++11 threading,
as it doesn't see synchronization inside standard library. See
http://lists.cs.uiuc.edu/pipermail/cfe-dev/2014-February/035408.html
for an example of such case.

We may build custom TSan-instrumented version libcxx to fight with that.
This change adds build rules for libcxx_tsan and integrates it into
testing infrastructure.

llvm-svn: 208737

compiler-rt/lib/tsan/CMakeLists.txt

@@ -75,6 +75,7 @@ set(TSAN_HEADERS
   rtl/tsan_update_shadow_word_inl.h
   rtl/tsan_vector.h)
 
+set(TSAN_RUNTIME_LIBRARIES)
 add_custom_target(tsan)
 # TSan is currently supported on 64-bit Linux only.
 if(CAN_TARGET_x86_64 AND UNIX AND NOT APPLE)
@@ -90,6 +91,7 @@ if(CAN_TARGET_x86_64 AND UNIX AND NOT APPLE)
             $<TARGET_OBJECTS:RTSanitizerCommonLibc.${arch}>
     CFLAGS ${TSAN_RTL_CFLAGS}
     DEFS ${TSAN_COMMON_DEFINITIONS})
+  list(APPEND TSAN_RUNTIME_LIBRARIES clang_rt.tsan-${arch})
   add_sanitizer_rt_symbols(clang_rt.tsan-${arch} rtl/tsan.syms.extra)
   add_dependencies(tsan clang_rt.tsan-${arch}
     clang_rt.tsan-${arch}-symbols)
@@ -97,6 +99,14 @@ endif()
 
 add_dependencies(compiler-rt tsan)
 
+# Build libcxx instrumented with TSan.
+if(COMPILER_RT_HAS_LIBCXX_SOURCES)
+  set(LIBCXX_PREFIX ${CMAKE_CURRENT_BINARY_DIR}/libcxx_tsan)
+  add_custom_libcxx(libcxx_tsan ${LIBCXX_PREFIX}
+    DEPS ${TSAN_RUNTIME_LIBRARIES}
+    CFLAGS -fsanitize=thread)
+endif()
+
 if(COMPILER_RT_INCLUDE_TESTS)
   add_subdirectory(tests)
 endif()

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

@@ -16,6 +16,7 @@ set_default("llvm_build_mode", "@LLVM_BUILD_MODE@")
 set_default("llvm_src_root", "@LLVM_SOURCE_DIR@")
 set_default("llvm_obj_root", "@LLVM_BINARY_DIR@")
 set_default("compiler_rt_src_root", "@COMPILER_RT_SOURCE_DIR@")
+set_default("compiler_rt_obj_root", "@COMPILER_RT_BINARY_DIR@")
 set_default("llvm_tools_dir", "@LLVM_TOOLS_DIR@")
 set_default("clang", "@COMPILER_RT_TEST_COMPILER@")
 set_default("compiler_id", "@COMPILER_RT_TEST_COMPILER_ID@")

compiler-rt/test/tsan/CMakeLists.txt

@@ -1,11 +1,17 @@
-configure_lit_site_cfg(
-  ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
-  ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg)
-
 set(TSAN_TEST_DEPS ${SANITIZER_COMMON_LIT_TEST_DEPS})
 if(NOT COMPILER_RT_STANDALONE_BUILD)
   list(APPEND TSAN_TEST_DEPS tsan)
 endif()
+if(COMPILER_RT_HAS_LIBCXX_SOURCES)
+  list(APPEND TSAN_TEST_DEPS libcxx_tsan)
+  set(TSAN_HAS_LIBCXX True)
+else()
+  set(TSAN_HAS_LIBCXX False)
+endif()
+
+configure_lit_site_cfg(
+  ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
+  ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg)
 
 if(COMPILER_RT_INCLUDE_TESTS)
   configure_lit_site_cfg(

compiler-rt/test/tsan/libcxx/lit.local.cfg

@@ -0,0 +1,10 @@
+def getRoot(config):
+  if not config.parent:
+    return config
+  return getRoot(config.parent)
+
+root = getRoot(config)
+
+if not root.has_libcxx:
+  config.unsupported = True
+

compiler-rt/test/tsan/libcxx/std_shared_ptr.cc

@@ -0,0 +1,24 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+#include <stdio.h>
+#include <memory>
+#include <thread>
+
+int main() {
+  int v1 = 0;
+  int v2 = 0;
+  std::thread t1;
+  std::thread t2;
+
+  {
+     auto thingy = std::make_shared<int>(42);
+     t1 = std::thread([thingy, &v1] { v1 = *thingy; });
+     t2 = std::thread([thingy, &v2] { v2 = *thingy; });
+  }
+
+  t1.join();
+  t2.join();
+  printf("%d %d\n", v1, v2);
+  // CHECK-NOT: ThreadSanitizer: data race
+  // CHECK: 42 42
+  return 0;
+}

compiler-rt/test/tsan/lit.cfg

@@ -31,6 +31,18 @@ clang_tsan_cflags = ["-fsanitize=thread",
                      "-ldl",
                      "-m64"]
 clang_tsan_cxxflags = config.cxx_mode_flags + clang_tsan_cflags
+# Add additional flags if we're using instrumented libc++.
+if config.has_libcxx:
+  # FIXME: Dehardcode this path somehow.
+  libcxx_path = os.path.join(config.compiler_rt_obj_root, "lib",
+                             "tsan", "libcxx_tsan")
+  libcxx_incdir = os.path.join(libcxx_path, "include", "c++", "v1")
+  libcxx_libdir = os.path.join(libcxx_path, "lib")
+  libcxx_so = os.path.join(libcxx_libdir, "libc++.so")
+  clang_tsan_cxxflags += ["-std=c++11",
+                          "-I%s" % libcxx_incdir,
+                          libcxx_so,
+                          "-Wl,-rpath=%s" % libcxx_libdir]
 
 def build_invocation(compile_flags):
   return " " + " ".join([config.clang] + compile_flags) + " "

compiler-rt/test/tsan/lit.site.cfg.in

@@ -1,6 +1,8 @@
 ## Autogenerated by LLVM/Clang configuration.
 # Do not edit!
 
+config.has_libcxx = @TSAN_HAS_LIBCXX@
+
 # Load common config for all compiler-rt lit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/test/lit.common.configured")