[UBSan] Use shared library for UBSan on OS X (Clang part).

[samsonov]

Summary

UBSan is now used in the same way as ASan, and is supported on
OSX and on iOS simulator. At the moment ASan and UBSan can't be used
together due to PR21112, but I hope to resolve it soon by
embedding UBSan into ASan.

[samsonov]

• Update to still allow ASan+UBSan combination.

cfe/trunk/lib/Driver/ToolChains.h

public:
 
   virtual void addClangWarningOptions(llvm::opt::ArgStringList &CC1Args)
                                                       const override;
 
   void
   AddLinkARCArgs(const llvm::opt::ArgList &Args,
                  llvm::opt::ArgStringList &CmdArgs) const override;
   /// }
+
+private:
+  void AddLinkSanitizerLibArgs(const llvm::opt::ArgList &Args,
+                               llvm::opt::ArgStringList &CmdArgs,
+                               StringRef Sanitizer) const;
 };
 
 class LLVM_LIBRARY_VISIBILITY Generic_ELF : public Generic_GCC {
   virtual void anchor();
 public:
   Generic_ELF(const Driver &D, const llvm::Triple &Triple,
               const llvm::opt::ArgList &Args)
       : Generic_GCC(D, Triple, Args) {}

cfe/trunk/lib/Driver/ToolChains.cpp

if (AddRPath) {
 
     // Add the path to the resource dir to rpath to support using the dylib
     // from the default location without copying.
     CmdArgs.push_back("-rpath");
     CmdArgs.push_back(Args.MakeArgString(Dir));
   }
 }
 
+void DarwinClang::AddLinkSanitizerLibArgs(const ArgList &Args,
+                                          ArgStringList &CmdArgs,
+                                          StringRef Sanitizer) const {
+  if (!Args.hasArg(options::OPT_dynamiclib) &&
+      !Args.hasArg(options::OPT_bundle)) {
+    // Sanitizer runtime libraries requires C++.
+    AddCXXStdlibLibArgs(Args, CmdArgs);
+  }
+  assert(isTargetMacOS() || isTargetIOSSimulator());
+  StringRef OS = isTargetMacOS() ? "osx" : "iossim";
+  AddLinkRuntimeLib(Args, CmdArgs, (Twine("libclang_rt.") + Sanitizer + "_" +
+                                    OS + "_dynamic.dylib").str(),
+                    /*AlwaysLink*/ true, /*IsEmbedded*/ false,
+                    /*AddRPath*/ true);
+}
+
 void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
                                         ArgStringList &CmdArgs) const {
   // Darwin only supports the compiler-rt based runtime libraries.
   switch (GetRuntimeLibType(Args)) {
   case ToolChain::RLT_CompilerRT:
     break;
   default:
     getDriver().Diag(diag::err_drv_unsupported_rtlib_for_platform)
if (Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
     if (isTargetIOSBased())
       AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.profile_ios.a");
     else
       AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.profile_osx.a");
   }
 
   const SanitizerArgs &Sanitize = getSanitizerArgs();
 
-  // Add Ubsan runtime library, if required.
-  if (Sanitize.needsUbsanRt()) {
+  if (Sanitize.needsAsanRt()) {
+    if (!isTargetMacOS() && !isTargetIOSSimulator()) {
       // FIXME: Move this check to SanitizerArgs::filterUnsupportedKinds.
-    if (isTargetIOSBased()) {
       getDriver().Diag(diag::err_drv_clang_unsupported_per_platform)
-        << "-fsanitize=undefined";
+          << "-fsanitize=address";
     } else {
-      assert(isTargetMacOS() && "unexpected non OS X target");
-      AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.ubsan_osx.a", true);
-
-      // The Ubsan runtime library requires C++.
-      AddCXXStdlibLibArgs(Args, CmdArgs);
+      AddLinkSanitizerLibArgs(Args, CmdArgs, "asan");
     }
   }
 
-  // Add ASAN runtime library, if required. Dynamic libraries and bundles
-  // should not be linked with the runtime library.
-  if (Sanitize.needsAsanRt()) {
+  if (Sanitize.needsUbsanRt()) {
+    if (!isTargetMacOS() && !isTargetIOSSimulator()) {
       // FIXME: Move this check to SanitizerArgs::filterUnsupportedKinds.
-    if (isTargetIPhoneOS()) {
       getDriver().Diag(diag::err_drv_clang_unsupported_per_platform)
-        << "-fsanitize=address";
-    } else {
-      if (!Args.hasArg(options::OPT_dynamiclib) &&
-          !Args.hasArg(options::OPT_bundle)) {
-        // The ASAN runtime library requires C++.
-        AddCXXStdlibLibArgs(Args, CmdArgs);
-      }
-      if (isTargetMacOS()) {
-        AddLinkRuntimeLib(Args, CmdArgs,
-                          "libclang_rt.asan_osx_dynamic.dylib",
-                          /*AlwaysLink*/ true, /*IsEmbedded*/ false,
-                          /*AddRPath*/ true);
-      } else {
-        if (isTargetIOSSimulator()) {
-          AddLinkRuntimeLib(Args, CmdArgs,
-                            "libclang_rt.asan_iossim_dynamic.dylib",
-                            /*AlwaysLink*/ true, /*IsEmbedded*/ false,
-                            /*AddRPath*/ true);
-        }
-      }
+          << "-fsanitize=undefined";
+      AddLinkSanitizerLibArgs(Args, CmdArgs, "ubsan");
+      // Add explicit dependcy on -lc++abi, as -lc++ doesn't re-export
+      // all RTTI-related symbols that UBSan uses.
+      CmdArgs.push_back("-lc++abi");
     }
   }
 
   // Otherwise link libSystem, then the dynamic runtime library, and finally any
   // target specific static runtime library.
   CmdArgs.push_back("-lSystem");
 
   // Select the dynamic runtime library and the target specific static library.

cfe/trunk/runtime/compiler-rt/Makefile

 # support.
 RuntimeDirs :=
 ifeq ($(OS),Darwin)
 RuntimeDirs += darwin macho_embedded
 RuntimeLibrary.darwin.Configs := \
   eprintf.a 10.4.a osx.a cc_kext.a \
   asan_osx_dynamic.dylib \
   profile_osx.a \
-  ubsan_osx.a
+  ubsan_osx_dynamic.dylib
 
 IOS_SDK := $(shell xcrun --show-sdk-path -sdk iphoneos 2> /dev/null)
 IOSSIM_SDK := $(shell xcrun --show-sdk-path -sdk iphonesimulator 2> /dev/null)
 
 ifneq ($(IOS_SDK)$(IOSSIM_SDK),)
 RuntimeLibrary.darwin.Configs += ios.a profile_ios.a
 endif
 
 ifneq ($(IOS_SDK),)
 RuntimeLibrary.darwin.Configs += cc_kext_ios5.a
 endif
 
 ifneq ($(IOSSIM_SDK),)
-RuntimeLibrary.darwin.Configs += asan_iossim_dynamic.dylib
+RuntimeLibrary.darwin.Configs += asan_iossim_dynamic.dylib \
+                                 ubsan_iossim_dynamic.dylib
 endif
 
 RuntimeLibrary.macho_embedded.Configs := \
   hard_static.a hard_pic.a
 ifneq (,$(findstring ARM,$(TARGETS_TO_BUILD)))
 RuntimeLibrary.macho_embedded.Configs += \
   soft_static.a soft_pic.a
 endif

cfe/trunk/test/Driver/darwin-sanitizer-ld.c

 // CHECK-DYN-ASAN: "-rpath" "@executable_path"
 // CHECK-DYN-ASAN: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -fsanitize=undefined %s -o %t.o 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-UBSAN %s
 
 // CHECK-UBSAN: "{{.*}}ld{{(.exe)?}}"
-// CHECK-UBSAN: libclang_rt.ubsan_osx.a"
 // CHECK-UBSAN: stdc++
+// CHECK-UBSAN: libclang_rt.ubsan_osx_dynamic.dylib"
+// CHECK-UBSAN: "-rpath" "@executable_path"
+// CHECK-UBSAN: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -fsanitize=bounds -fsanitize-undefined-trap-on-error \
 // RUN:   %s -o %t.o 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-BOUNDS %s
 
 // CHECK-BOUNDS: "{{.*}}ld{{(.exe)?}}"
 // CHECK-BOUNDS-NOT: libclang_rt.ubsan_osx.a"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -fPIC -shared -fsanitize=undefined %s -o %t.so 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-DYN-UBSAN %s
 
 // CHECK-DYN-UBSAN: "{{.*}}ld{{(.exe)?}}"
 // CHECK-DYN-UBSAN: "-dylib"
-// CHECK-DYN-UBSAN: libclang_rt.ubsan_osx.a
+// CHECK-DYN-UBSAN: libclang_rt.ubsan_osx_dynamic.dylib"
+// CHECK-DYN-UBSAN: "-rpath" "@executable_path"
+// CHECK-DYN-UBSAN: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -fsanitize=bounds -fsanitize-undefined-trap-on-error \
 // RUN:   %s -o %t.so -fPIC -shared 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-DYN-BOUNDS %s
 
 // CHECK-DYN-BOUNDS: "{{.*}}ld{{(.exe)?}}"
-// CHECK-DYN-BOUNDS-NOT: libclang_rt.ubsan_osx.a
+// CHECK-DYN-BOUNDS-NOT: ubsan_osx