[ubsan] Split ubsan_init_standalone

[vitalybuka]

Summary

On Linux we may need preinit_array in static lib and
ubsan_standalone_initializer in shared lib.

[vitalybuka]

Rebase

compiler-rt/lib/ubsan/CMakeLists.txt

add_compiler_rt_object_libraries(UbsanDynamicRuntimeThunk
       ${SANITIZER_COMMON_SUPPORTED_OS}
       ARCHS ${UBSAN_SUPPORTED_ARCH}
       SOURCES ubsan_win_dynamic_runtime_thunk.cc
       CFLAGS ${UBSAN_CFLAGS} ${DYNAMIC_RUNTIME_THUNK_CFLAGS}
       DEFS ${UBSAN_COMMON_DEFINITIONS})
   endif()
 
   if(COMPILER_RT_HAS_UBSAN)
-    # Initializer of standalone UBSan runtime.
     add_compiler_rt_object_libraries(RTUbsan_standalone
       ARCHS ${UBSAN_SUPPORTED_ARCH}
-      SOURCES ${UBSAN_STANDALONE_SOURCES} CFLAGS ${UBSAN_STANDALONE_CFLAGS})
+      SOURCES ${UBSAN_STANDALONE_SOURCES}
+      CFLAGS ${UBSAN_STANDALONE_CFLAGS})
 
     # Standalone UBSan runtimes.
     add_compiler_rt_runtime(clang_rt.ubsan_standalone
       STATIC
       ARCHS ${UBSAN_SUPPORTED_ARCH}
+      SOURCES ubsan_init_standalone_preinit.cc
       OBJECT_LIBS RTSanitizerCommon
               RTSanitizerCommonLibc
               RTUbsan
               RTUbsan_standalone
       CFLAGS ${UBSAN_CFLAGS}
       PARENT_TARGET ubsan)
 
     add_compiler_rt_runtime(clang_rt.ubsan_standalone_cxx
       STATIC
       ARCHS ${UBSAN_SUPPORTED_ARCH}
       OBJECT_LIBS RTUbsan_cxx
       CFLAGS ${UBSAN_CXXFLAGS}
       PARENT_TARGET ubsan)
 
     if (UNIX)
       add_compiler_rt_runtime(clang_rt.ubsan_standalone
         SHARED
         ARCHS ${UBSAN_SUPPORTED_ARCH}
         OBJECT_LIBS RTSanitizerCommon
-                RTSanitizerCommonLibc
-                RTUbsan
+              RTUbsan_standalone
         CFLAGS ${UBSAN_CFLAGS}
         LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS}
         LINK_LIBS ${UBSAN_DYNAMIC_LIBS}
         PARENT_TARGET ubsan)
 
       add_compiler_rt_runtime(clang_rt.ubsan_standalone_cxx
         SHARED
         ARCHS ${UBSAN_SUPPORTED_ARCH}

compiler-rt/lib/ubsan/ubsan_init.cc

 #include "sanitizer_common/sanitizer_symbolizer.h"
 
 using namespace __ubsan;
 
 const char *__ubsan::GetSanititizerToolName() {
   return "UndefinedBehaviorSanitizer";
 }
 
-static enum {
-  UBSAN_MODE_UNKNOWN = 0,
-  UBSAN_MODE_STANDALONE,
-  UBSAN_MODE_PLUGIN
-} ubsan_mode;
+static bool ubsan_initialized;
 static StaticSpinMutex ubsan_init_mu;
 
 static void CommonInit() {
   InitializeSuppressions();
 }
 
 static void CommonStandaloneInit() {
   SanitizerToolName = GetSanititizerToolName();
   CacheBinaryName();
   InitializeFlags();
   __sanitizer_set_report_path(common_flags()->log_path);
   AndroidLogInit();
   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
   CommonInit();
-  ubsan_mode = UBSAN_MODE_STANDALONE;
 }
 
 void __ubsan::InitAsStandalone() {
-  if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
-    CHECK_EQ(UBSAN_MODE_UNKNOWN, ubsan_mode);
-    CommonStandaloneInit();
-    return;
-  }
   SpinMutexLock l(&ubsan_init_mu);
-  CHECK_NE(UBSAN_MODE_PLUGIN, ubsan_mode);
-  if (ubsan_mode == UBSAN_MODE_UNKNOWN)
+  if (!ubsan_initialized) {
     CommonStandaloneInit();
+    ubsan_initialized = true;
   }
-
-void __ubsan::InitAsStandaloneIfNecessary() {
-  if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
-    CHECK_NE(UBSAN_MODE_UNKNOWN, ubsan_mode);
-    return;
-  }
-  SpinMutexLock l(&ubsan_init_mu);
-  if (ubsan_mode == UBSAN_MODE_UNKNOWN)
-    CommonStandaloneInit();
 }
 
+void __ubsan::InitAsStandaloneIfNecessary() { return InitAsStandalone(); }
+
 void __ubsan::InitAsPlugin() {
-#if !SANITIZER_CAN_USE_PREINIT_ARRAY
   SpinMutexLock l(&ubsan_init_mu);
-#endif
-  CHECK_EQ(UBSAN_MODE_UNKNOWN, ubsan_mode);
+  if (!ubsan_initialized) {
     CommonInit();
-  ubsan_mode = UBSAN_MODE_PLUGIN;
+    ubsan_initialized = true;
+  }
 }
 
 #endif  // CAN_SANITIZE_UB

compiler-rt/lib/ubsan/ubsan_init_standalone.cc

 #include "ubsan_platform.h"
 #if !CAN_SANITIZE_UB
 # error "UBSan is not supported on this platform!"
 #endif
 
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "ubsan_init.h"
 
-#if SANITIZER_CAN_USE_PREINIT_ARRAY
-__attribute__((section(".preinit_array"), used))
-void (*__local_ubsan_preinit)(void) = __ubsan::InitAsStandalone;
-#else
-// Use a dynamic initializer.
 class UbsanStandaloneInitializer {
  public:
   UbsanStandaloneInitializer() {
     __ubsan::InitAsStandalone();
   }
 };
 static UbsanStandaloneInitializer ubsan_standalone_initializer;
-#endif  // SANITIZER_CAN_USE_PREINIT_ARRAY
-

compiler-rt/lib/ubsan/ubsan_init_standalone_preinit.cc

-//===-- ubsan_init_standalone.cc ------------------------------------------===//
+//===-- ubsan_init_standalone_preinit.cc
+//------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Initialization of standalone UBSan runtime.
 //
 //===----------------------------------------------------------------------===//
 
 #include "ubsan_platform.h"
 #if !CAN_SANITIZE_UB
-# error "UBSan is not supported on this platform!"
+#error "UBSan is not supported on this platform!"
 #endif
 
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "ubsan_init.h"
 
 #if SANITIZER_CAN_USE_PREINIT_ARRAY
-__attribute__((section(".preinit_array"), used))
-void (*__local_ubsan_preinit)(void) = __ubsan::InitAsStandalone;
-#else
-// Use a dynamic initializer.
-class UbsanStandaloneInitializer {
- public:
-  UbsanStandaloneInitializer() {
-    __ubsan::InitAsStandalone();
-  }
-};
-static UbsanStandaloneInitializer ubsan_standalone_initializer;
-#endif  // SANITIZER_CAN_USE_PREINIT_ARRAY
-
+__attribute__((section(".preinit_array"), used)) void (*__local_ubsan_preinit)(
+    void) = __ubsan::InitAsStandalone;
+#endif // SANITIZER_CAN_USE_PREINIT_ARRAY