Copy LLVM's ThreadSanitizer (TSan) library to LDC's libraries like we do for ASan, and set the correct linker flags (#3522)

* Copy LLVM's ThreadSanitizer (TSan) library to LDC's libraries like we do for ASan, and set the correct linker flags.

Requires at least LLVM 8 for executable TSan test cases and TSan execution is not supported on Windows.

Author: JohanEngelen

CMakeLists.txt

@@ -763,6 +763,7 @@ if (LDC_INSTALL_LLVM_RUNTIME_LIBS)
 
     if(APPLE)
         copy_compilerrt_lib("darwin/libclang_rt.asan_osx_dynamic.dylib" "libldc_rt.asan.dylib" TRUE)
+        copy_compilerrt_lib("darwin/libclang_rt.tsan_osx_dynamic.dylib" "libldc_rt.tsan.dylib" TRUE)
         copy_compilerrt_lib("darwin/libclang_rt.osx.a"                  "libldc_rt.builtins.a" FALSE)
         copy_compilerrt_lib("darwin/libclang_rt.profile_osx.a"          "libldc_rt.profile.a"  FALSE)
         copy_compilerrt_lib("darwin/libclang_rt.fuzzer_osx.a"           "libldc_rt.fuzzer.a"   FALSE)
@@ -777,6 +778,7 @@ if (LDC_INSTALL_LLVM_RUNTIME_LIBS)
         set(LDC_INSTALL_LLVM_RUNTIME_LIBS_ARCH "x86_64" CACHE STRING "Non-Mac Posix: architecture used as libname suffix for the compiler-rt source libraries, e.g., 'aarch64'.")
 
         copy_compilerrt_lib("${LDC_INSTALL_LLVM_RUNTIME_LIBS_OS}/libclang_rt.asan-${LDC_INSTALL_LLVM_RUNTIME_LIBS_ARCH}.a"       "libldc_rt.asan.a"     FALSE)
+        copy_compilerrt_lib("${LDC_INSTALL_LLVM_RUNTIME_LIBS_OS}/libclang_rt.tsan-${LDC_INSTALL_LLVM_RUNTIME_LIBS_ARCH}.a"       "libldc_rt.tsan.a"     FALSE)
         copy_compilerrt_lib("${LDC_INSTALL_LLVM_RUNTIME_LIBS_OS}/libclang_rt.builtins-${LDC_INSTALL_LLVM_RUNTIME_LIBS_ARCH}.a"   "libldc_rt.builtins.a" FALSE)
         copy_compilerrt_lib("${LDC_INSTALL_LLVM_RUNTIME_LIBS_OS}/libclang_rt.profile-${LDC_INSTALL_LLVM_RUNTIME_LIBS_ARCH}.a"    "libldc_rt.profile.a"  FALSE)
         copy_compilerrt_lib("${LDC_INSTALL_LLVM_RUNTIME_LIBS_OS}/libclang_rt.xray-${LDC_INSTALL_LLVM_RUNTIME_LIBS_ARCH}.a"       "libldc_rt.xray.a"     FALSE)

driver/linker-gcc.cpp

@@ -56,7 +56,9 @@ class ArgsBuilder {
 
 private:
   virtual void addSanitizers(const llvm::Triple &triple);
-  virtual void addASanLinkFlags(const llvm::Triple &triple);
+  virtual void addSanitizerLinkFlags(const llvm::Triple &triple,
+                                     const llvm::StringRef sanitizerName,
+                                     const llvm::StringRef fallbackFlag);
   virtual void addFuzzLinkFlags(const llvm::Triple &triple);
   virtual void addCppStdlibLinkFlags(const llvm::Triple &triple);
   virtual void addProfileRuntimeLinkFlags(const llvm::Triple &triple);
@@ -279,27 +281,29 @@ getFullCompilerRTLibPathCandidates(llvm::StringRef baseName,
   return r;
 }
 
-void ArgsBuilder::addASanLinkFlags(const llvm::Triple &triple) {
-  // Examples: "libclang_rt.asan-x86_64.a" or "libclang_rt.asan-arm.a" and
-  // "libclang_rt.asan-x86_64.so"
+void ArgsBuilder::addSanitizerLinkFlags(const llvm::Triple &triple,
+                                        const llvm::StringRef sanitizerName,
+                                        const llvm::StringRef fallbackFlag) {
+  // Examples: "libclang_rt.tsan-x86_64.a" or "libclang_rt.tsan-arm.a" and
+  // "libclang_rt.tsan-x86_64.so"
 
   // TODO: let user choose to link with shared lib.
   // In case of shared ASan, I think we also need to statically link with
   // libclang_rt.asan-preinit-<arch>.a on Linux. On Darwin, the only option is
   // to use the shared library.
-  bool linkSharedASan = triple.isOSDarwin();
+  bool linkSharedLibrary = triple.isOSDarwin();
   const auto searchPaths =
-      getFullCompilerRTLibPathCandidates("asan", triple, linkSharedASan);
+      getFullCompilerRTLibPathCandidates(sanitizerName, triple, linkSharedLibrary);
 
   for (const auto &filepath : searchPaths) {
-    IF_LOG Logger::println("Searching ASan lib: %s", filepath.c_str());
+    IF_LOG Logger::println("Searching sanitizer lib: %s", filepath.c_str());
 
     if (llvm::sys::fs::exists(filepath) &&
         !llvm::sys::fs::is_directory(filepath)) {
       IF_LOG Logger::println("Found, linking with %s", filepath.c_str());
       args.push_back(filepath);
 
-      if (linkSharedASan) {
+      if (linkSharedLibrary) {
         // Add @executable_path to rpath to support having the shared lib copied
         // with the executable.
         args.push_back("-rpath");
@@ -315,11 +319,9 @@ void ArgsBuilder::addASanLinkFlags(const llvm::Triple &triple) {
     }
   }
 
-  // When we reach here, we did not find the ASan library.
-  // Fallback, requires Clang. The asan library contains a versioned symbol
-  // name and a linker error will happen when the LDC-LLVM and Clang-LLVM
-  // versions don't match.
-  args.push_back("-fsanitize=address");
+  // When we reach here, we did not find the sanitizer library.
+  // Fallback, requires Clang.
+  args.push_back(fallbackFlag);
 }
 
 // Adds all required link flags for -fsanitize=fuzzer when libFuzzer library is
@@ -446,7 +448,7 @@ void ArgsBuilder::addProfileRuntimeLinkFlags(const llvm::Triple &triple) {
 
 void ArgsBuilder::addSanitizers(const llvm::Triple &triple) {
   if (opts::isSanitizerEnabled(opts::AddressSanitizer)) {
-    addASanLinkFlags(triple);
+    addSanitizerLinkFlags(triple, "asan", "-fsanitize=address");
   }
 
   if (opts::isSanitizerEnabled(opts::FuzzSanitizer)) {
@@ -459,10 +461,8 @@ void ArgsBuilder::addSanitizers(const llvm::Triple &triple) {
     args.push_back("-fsanitize=memory");
   }
 
-  // TODO: instead of this, we should link with our own sanitizer libraries
-  // because LDC's LLVM version could be different from the system clang.
   if (opts::isSanitizerEnabled(opts::ThreadSanitizer)) {
-    args.push_back("-fsanitize=thread");
+    addSanitizerLinkFlags(triple, "tsan", "-fsanitize=thread");
   }
 }
 

tests/sanitizers/deflake.bash

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+# Copied from LLVM's testsuite: compiler-rt/test/tsan
+
+# This script is used to deflake inherently flaky tsan tests.
+# It is invoked from lit tests as:
+# %deflake $THRESHOLD  mybinary
+# which is then substituted by lit to:
+# $(dirname %s)/deflake.bash $THRESHOLD mybinary
+# - When TSAN_TEST_DEFLAKE_THRESHOLD is defined to a positive integer value,
+#   THRESHOLD will be the defined value.
+# - When TSAN_TEST_DEFLAKE_THRESHOLD is not defined, THRESHOLD will be 10.
+# The script runs the target program up to $THRESHOLD times,
+# until it fails (i.e. produces a race report).
+
+THRESHOLD="${1}"
+shift
+
+# Early exit if $THRESHOLD is not a non-negative integer
+[[  "${THRESHOLD}" =~ ^[0-9]+$ ]] || exit 1
+
+while (( THRESHOLD-- )); do
+    OUT=`$@ 2>&1`
+    if [[ $? != 0 ]]; then
+        echo "$OUT"
+        exit 0
+    fi
+done
+exit 1

tests/sanitizers/lit.local.cfg

@@ -11,6 +11,10 @@ if (platform.system() == 'Darwin') or (platform.system() == 'Linux'):
         if m is not None:
             config.available_features.add('ASan')
             continue
+        m = re.match('.*tsan.*', file)
+        if m is not None:
+            config.available_features.add('TSan')
+            continue
         m = re.match('.*(F|f)uzzer.*', file)
         if m is not None:
             config.available_features.add('Fuzzer')
@@ -25,3 +29,6 @@ if 'ASan' in config.available_features:
     config.substitutions.append(('%env_asan_opts=',
                                  'env ASAN_OPTIONS=' + default_asan_options + ':'))
 
+# Add the %deflake substitution, to help with flaky tests.
+# Usage: "%deflake <count> <program>", runs <program> a maximum of <count> times until a failure occurs.
+config.substitutions.append( ("%deflake", os.path.join(os.path.dirname(__file__), "deflake.bash")))

tests/sanitizers/tsan_noerror.d

@@ -0,0 +1,14 @@
+// Test that a simple program passes ThreadSanitizer without error
+
+// REQUIRES: TSan
+
+// XFAIL: *
+// Druntime does not yet work with ThreadSanitizer.
+// See Github issue 3519 (https://github.com/ldc-developers/ldc/issues/3519)
+
+// RUN: %ldc -fsanitize=thread %s -of=%t%exe
+// RUN: %t%exe
+
+void main()
+{
+}

tests/sanitizers/tsan_tiny_race.d

@@ -0,0 +1,62 @@
+// Test that ThreadSanitizer+LDC works on a very basic testcase.
+// Note that -betterC is used, to avoid relying on druntime for this test.
+
+// REQUIRES: TSan
+// REQUIRES: atleast_llvm800
+
+// RUN: %ldc -betterC -g -fsanitize=thread %s -of=%t%exe
+// RUN: %deflake 20 %t%exe | FileCheck %s
+
+// CHECK: WARNING: ThreadSanitizer: data race
+
+import core.sys.posix.pthread;
+
+shared int global;
+
+extern(C)
+void *thread1(void *x) {
+  barrier_wait(&barrier);
+// CHECK-DAG: thread1{{.*}}[[@LINE+1]]
+  global = 42;
+  return x;
+}
+
+extern(C)
+int main() {
+  barrier_init(&barrier, 2);
+  pthread_t t;
+  pthread_create(&t, null, &thread1, null);
+// CHECK-DAG: main{{.*}}[[@LINE+1]]
+  global = 43;
+  barrier_wait(&barrier);
+  pthread_join(t, null);
+  return global;
+}
+
+//----------------------------------------------------------------------------
+// Code to facilitate thread synchronization to make this test deterministic.
+// See LLVM: compiler-rt/test/tsan/test.h
+
+// TSan-invisible barrier.
+// Tests use it to establish necessary execution order in a way that does not
+// interfere with tsan (does not establish synchronization between threads).
+alias invisible_barrier_t = __c_ulonglong;
+import core.stdc.config;
+alias __c_unsigned = uint;
+// Default instance of the barrier, but a test can declare more manually.
+__gshared invisible_barrier_t barrier;
+
+extern (C) {
+  // These functions reside inside the tsan library.
+  void __tsan_testonly_barrier_init(invisible_barrier_t *barrier, __c_unsigned count);
+  void __tsan_testonly_barrier_wait(invisible_barrier_t *barrier);
+}
+
+void barrier_init(invisible_barrier_t *barrier, __c_unsigned count) {
+  __tsan_testonly_barrier_init(barrier, count);
+}
+
+void barrier_wait(invisible_barrier_t *barrier) {
+  __tsan_testonly_barrier_wait(barrier);
+}
+//----------------------------------------------------------------------------

tests/sanitizers/tsan_tiny_race_TLS.d

@@ -0,0 +1,61 @@
+// Test that ThreadSanitizer+LDC works on a very basic testcase.
+// Note that -betterC is used, to avoid relying on druntime for this test.
+
+// REQUIRES: TSan
+// REQUIRES: atleast_llvm800
+
+// RUN: %ldc -betterC -g -fsanitize=thread %s -of=%t%exe
+// RUN: %deflake 20 %t%exe | FileCheck %s
+
+// CHECK: WARNING: ThreadSanitizer: data race
+
+import core.sys.posix.pthread;
+
+extern(C)
+void *thread1(void *x) {
+  barrier_wait(&barrier);
+// CHECK-DAG: thread1{{.*}}[[@LINE+1]]
+  *cast(int*)x = 42;
+  return x;
+}
+
+extern(C)
+int main() {
+  int tls_variable;
+  barrier_init(&barrier, 2);
+  pthread_t t;
+  pthread_create(&t, null, &thread1, &tls_variable);
+// CHECK-DAG: main{{.*}}[[@LINE+1]]
+  tls_variable = 43;
+  barrier_wait(&barrier);
+  pthread_join(t, null);
+  return 0;
+}
+
+//----------------------------------------------------------------------------
+// Code to facilitate thread synchronization to make this test deterministic.
+// See LLVM: compiler-rt/test/tsan/test.h
+
+// TSan-invisible barrier.
+// Tests use it to establish necessary execution order in a way that does not
+// interfere with tsan (does not establish synchronization between threads).
+alias invisible_barrier_t = __c_ulonglong;
+import core.stdc.config;
+alias __c_unsigned = uint;
+// Default instance of the barrier, but a test can declare more manually.
+__gshared invisible_barrier_t barrier;
+
+extern (C) {
+  // These functions reside inside the tsan library.
+  void __tsan_testonly_barrier_init(invisible_barrier_t *barrier, __c_unsigned count);
+  void __tsan_testonly_barrier_wait(invisible_barrier_t *barrier);
+}
+
+void barrier_init(invisible_barrier_t *barrier, __c_unsigned count) {
+  __tsan_testonly_barrier_init(barrier, count);
+}
+
+void barrier_wait(invisible_barrier_t *barrier) {
+  __tsan_testonly_barrier_wait(barrier);
+}
+//----------------------------------------------------------------------------