Support: Clean up TSan annotations.

[pcc]

Summary

Remove support for Valgrind-based TSan, which hasn't been maintained for a
few years. We now use the TSan annotations only if LLVM is compiled with
-fsanitize=thread. We no longer need the weak function definitions as we
are guaranteed that our program is linked directly with the TSan runtime.

[eugenis]

lib/Support/ManagedStatic.cpp

17

why do you need this?

lib/Support/Statistic.cpp

27

why do you need this? Part of the following change?

[pcc]

lib/Support/ManagedStatic.cpp

17

This file uses tsan annotations, so it needs this header. I imagine we got away with this until now because ManagedStatic.h included Valgrind.h.

lib/Support/Statistic.cpp

27

Likewise

[dvyukov]

Isn't llvm now compiled with C++11? If so, it would make sense to replace these annotations with proper code. Uses of the annotations and code around looks terrifying.

include/llvm/PassSupport.h

 #ifndef LLVM_PASSSUPPORT_H
 #define LLVM_PASSSUPPORT_H
 
 #include "Pass.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/PassInfo.h"
 #include "llvm/PassRegistry.h"
 #include "llvm/Support/Atomic.h"
-#include "llvm/Support/Valgrind.h"
+#include "llvm/Support/Compiler.h"
 #include <vector>
 
 namespace llvm {
 
 class TargetMachine;
 
 #define CALL_ONCE_INITIALIZATION(function) \
   static volatile sys::cas_flag initialized = 0; \

include/llvm/Support/Compiler.h

 /// \macro LLVM_ADDRESS_SANITIZER_BUILD
 /// \brief Whether LLVM itself is built with AddressSanitizer instrumentation.
 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
 # define LLVM_ADDRESS_SANITIZER_BUILD 1
 #else
 # define LLVM_ADDRESS_SANITIZER_BUILD 0
 #endif
 
+/// \macro LLVM_THREAD_SANITIZER_BUILD
+/// \brief Whether LLVM itself is built with ThreadSanitizer instrumentation.
+#if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
+# define LLVM_THREAD_SANITIZER_BUILD 1
+#else
+# define LLVM_THREAD_SANITIZER_BUILD 0
+#endif
+
+#if LLVM_THREAD_SANITIZER_BUILD
+// Thread Sanitizer is a tool that finds races in code.
+// See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations .
+// tsan detects these exact functions by name.
+extern "C" {
+void AnnotateHappensAfter(const char *file, int line, const volatile void *cv);
+void AnnotateHappensBefore(const char *file, int line, const volatile void *cv);
+void AnnotateIgnoreWritesBegin(const char *file, int line);
+void AnnotateIgnoreWritesEnd(const char *file, int line);
+}
+
+// This marker is used to define a happens-before arc. The race detector will
+// infer an arc from the begin to the end when they share the same pointer
+// argument.
+# define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv)
+
+// This marker defines the destination of a happens-before arc.
+# define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv)
+
+// Ignore any races on writes between here and the next TsanIgnoreWritesEnd.
+# define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
+
+// Resume checking for racy writes.
+# define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
+#else
+# define TsanHappensBefore(cv)
+# define TsanHappensAfter(cv)
+# define TsanIgnoreWritesBegin()
+# define TsanIgnoreWritesEnd()
+#endif
+
 /// \brief Mark debug helper function definitions like dump() that should not be
 /// stripped from debug builds.
 // FIXME: Move this to a private config.h as it's not usable in public headers.
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
 #else
 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
 #endif

include/llvm/Support/ManagedStatic.h

 // This file defines the ManagedStatic class and the llvm_shutdown() function.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_SUPPORT_MANAGEDSTATIC_H
 #define LLVM_SUPPORT_MANAGEDSTATIC_H
 
 #include "llvm/Support/Atomic.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Threading.h"
-#include "llvm/Support/Valgrind.h"
 
 namespace llvm {
 
 /// object_creator - Helper method for ManagedStatic.
 template<class C>
 void* object_creator() {
   return new C();
 }

include/llvm/Support/Valgrind.h

 
 #ifndef LLVM_SUPPORT_VALGRIND_H
 #define LLVM_SUPPORT_VALGRIND_H
 
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/Compiler.h"
 #include <stddef.h>
 
-#if LLVM_ENABLE_THREADS != 0 && !defined(NDEBUG)
-// tsan (Thread Sanitizer) is a valgrind-based tool that detects these exact
-// functions by name.
-extern "C" {
-void AnnotateHappensAfter(const char *file, int line, const volatile void *cv);
-void AnnotateHappensBefore(const char *file, int line, const volatile void *cv);
-void AnnotateIgnoreWritesBegin(const char *file, int line);
-void AnnotateIgnoreWritesEnd(const char *file, int line);
-}
-#endif
-
 namespace llvm {
 namespace sys {
   // True if Valgrind is controlling this process.
   bool RunningOnValgrind();
 
   // Discard valgrind's translation of code in the range [Addr .. Addr + Len).
   // Otherwise valgrind may continue to execute the old version of the code.
   void ValgrindDiscardTranslations(const void *Addr, size_t Len);
-
-#if LLVM_ENABLE_THREADS != 0 && !defined(NDEBUG)
-  // Thread Sanitizer is a valgrind tool that finds races in code.
-  // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations .
-
-  // This marker is used to define a happens-before arc. The race detector will
-  // infer an arc from the begin to the end when they share the same pointer
-  // argument.
-  #define TsanHappensBefore(cv) \
-    AnnotateHappensBefore(__FILE__, __LINE__, cv)
-
-  // This marker defines the destination of a happens-before arc.
-  #define TsanHappensAfter(cv) \
-    AnnotateHappensAfter(__FILE__, __LINE__, cv)
-
-  // Ignore any races on writes between here and the next TsanIgnoreWritesEnd.
-  #define TsanIgnoreWritesBegin() \
-    AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
-
-  // Resume checking for racy writes.
-  #define TsanIgnoreWritesEnd() \
-    AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
-#else
-  #define TsanHappensBefore(cv)
-  #define TsanHappensAfter(cv)
-  #define TsanIgnoreWritesBegin()
-  #define TsanIgnoreWritesEnd()
-#endif
 }
 }
 
 #endif

lib/Support/ManagedStatic.cpp

 //===-- ManagedStatic.cpp - Static Global wrapper -------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the ManagedStatic class and llvm_shutdown().
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/Atomic.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/MutexGuard.h"
 #include <cassert>
 using namespace llvm;
 
 static const ManagedStaticBase *StaticList = nullptr;
 
 static sys::Mutex& getManagedStaticMutex() {

lib/Support/Statistic.cpp

 //
 // Later, in the code: ++NumInstEliminated;
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cstring>
 using namespace llvm;

lib/Support/Valgrind.cpp

 bool llvm::sys::RunningOnValgrind() {
   return false;
 }
 
 void llvm::sys::ValgrindDiscardTranslations(const void *Addr, size_t Len) {
 }
 
 #endif  // !HAVE_VALGRIND_VALGRIND_H
-
-// These functions require no implementation, tsan just looks at the arguments
-// they're called with. However, they are required to be weak as some other
-// application or library may already be providing these definitions for the
-// same reason we are.
-extern "C" {
-LLVM_ATTRIBUTE_WEAK void AnnotateHappensAfter(const char *file, int line,
-                                              const volatile void *cv);
-void AnnotateHappensAfter(const char *file, int line, const volatile void *cv) {
-}
-LLVM_ATTRIBUTE_WEAK void AnnotateHappensBefore(const char *file, int line,
-                                               const volatile void *cv);
-void AnnotateHappensBefore(const char *file, int line,
-                           const volatile void *cv) {}
-LLVM_ATTRIBUTE_WEAK void AnnotateIgnoreWritesBegin(const char *file, int line);
-void AnnotateIgnoreWritesBegin(const char *file, int line) {}
-LLVM_ATTRIBUTE_WEAK void AnnotateIgnoreWritesEnd(const char *file, int line);
-void AnnotateIgnoreWritesEnd(const char *file, int line) {}
-}
-