Driver: Stop linking to C++ when using sanitizers on Darwin

[kastiglione]

Summary

Sanitizers on Darwin are built as dynamic libraries, not static libraries. Sanitizers will have their C++ dependency satisfied internally (LC_LOAD_DYLIB) in the libclang_rt dylib. As long as the sanitizers stay dynamic and not static, linking against C++ when enabling a sanitizer becomes over linkage.

[compnerd]

Similar on all the sanitizers.

test/Driver/darwin-sanitizer-ld.c

8

I think that this can be made into a stronger assertion. Changing it to:

// CHECK-ASAN-NOT: stdc++

seems better.

While you are here, can you double up the tests and check against both libstdc++ and libc++?

[kastiglione]

Add CHECK-NOTs for C++

[compnerd]

LGTM; @beanz, any objections to this?

[compnerd]

Spoke with @beanz offline, he didnt have any concerns with this.

[compnerd]

SVN r274797

lib/Driver/ToolChains.cpp

void Darwin::addProfileRTLibs(const ArgList &Args,
   AddLinkRuntimeLib(Args, CmdArgs, (Twine("libclang_rt.profile_") +
        getOSLibraryNameSuffix() + ".a").str(),
                     /*AlwaysLink*/ true);
 }
 
 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);
-  }
-
   AddLinkRuntimeLib(
       Args, CmdArgs,
       (Twine("libclang_rt.") + Sanitizer + "_" +
        getOSLibraryNameSuffix() + "_dynamic.dylib").str(),
       /*AlwaysLink*/ true, /*IsEmbedded*/ false,
       /*AddRPath*/ true);
-
-  if (GetCXXStdlibType(Args) == ToolChain::CST_Libcxx) {
-    // Add explicit dependcy on -lc++abi, as -lc++ doesn't re-export
-    // all RTTI-related symbols that UBSan uses.
-    CmdArgs.push_back("-lc++abi");
-  }
 }
 
 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;

test/Driver/darwin-sanitizer-ld.c

 // Test sanitizer link flags on Darwin.
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -stdlib=platform -fsanitize=address %s -o %t.o 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-ASAN %s
 
 // CHECK-ASAN: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN: stdc++
+// CHECK-ASAN-NOT: "-lstdc++"
+// CHECK-ASAN-NOT: "-lc++"
 // CHECK-ASAN: libclang_rt.asan_osx_dynamic.dylib"
 // CHECK-ASAN: "-rpath" "@executable_path"
 // CHECK-ASAN: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -fPIC -shared -fsanitize=address %s -o %t.so 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-DYN-ASAN %s
 
 // CHECK-DYN-ASAN: "{{.*}}ld{{(.exe)?}}"
 // CHECK-DYN-ASAN: "-dylib"
 // CHECK-DYN-ASAN: libclang_rt.asan_osx_dynamic.dylib"
 // CHECK-DYN-ASAN: "-rpath" "@executable_path"
 // CHECK-DYN-ASAN: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -stdlib=platform -fsanitize=undefined %s -o %t.o 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-UBSAN %s
 
 // CHECK-UBSAN: "{{.*}}ld{{(.exe)?}}"
-// CHECK-UBSAN: stdc++
+// CHECK-UBSAN-NOT: "-lstdc++"
+// CHECK-UBSAN-NOT: "-lc++"
 // 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-DYN-BOUNDS: "{{.*}}ld{{(.exe)?}}"
 // CHECK-DYN-BOUNDS-NOT: ubsan_osx
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -stdlib=platform -fsanitize=address -mios-simulator-version-min=7.0 \
 // RUN:   %s -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-ASAN-IOSSIM %s
 
 // CHECK-ASAN-IOSSIM: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN-IOSSIM: lc++
+// CHECK-ASAN-IOSSIM-NOT: "-lstdc++"
+// CHECK-ASAN-IOSSIM-NOT: "-lc++"
 // CHECK-ASAN-IOSSIM: libclang_rt.asan_iossim_dynamic.dylib"
 // CHECK-ASAN-IOSSIM: "-rpath" "@executable_path"
 // CHECK-ASAN-IOSSIM: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -stdlib=platform -fsanitize=address \
 // RUN:   -mtvos-simulator-version-min=8.3.0 %s -o %t.o 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-ASAN-TVOSSIM %s
 
 // CHECK-ASAN-TVOSSIM: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN-TVOSSIM: lc++
+// CHECK-ASAN-TVOSSIM-NOT: "-lstdc++"
+// CHECK-ASAN-TVOSSIM-NOT: "-lc++"
 // CHECK-ASAN-TVOSSIM: libclang_rt.asan_tvossim_dynamic.dylib"
 // CHECK-ASAN-TVOSSIM: "-rpath" "@executable_path"
 // CHECK-ASAN-TVOSSIM: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target x86_64-darwin \
 // RUN:   -stdlib=platform -fsanitize=address \
 // RUN:   -mwatchos-simulator-version-min=2.0.0 %s -o %t.o 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-ASAN-WATCHOSSIM %s
 
 // CHECK-ASAN-WATCHOSSIM: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN-WATCHOSSIM: lc++
+// CHECK-ASAN-WATCHOSSIM-NOT: "-lstdc++"
+// CHECK-ASAN-WATCHOSSIM-NOT: "-lc++"
 // CHECK-ASAN-WATCHOSSIM: libclang_rt.asan_watchossim_dynamic.dylib"
 // CHECK-ASAN-WATCHOSSIM: "-rpath" "@executable_path"
 // CHECK-ASAN-WATCHOSSIM: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target armv7-apple-ios  \
 // RUN:   -stdlib=platform -fsanitize=address -miphoneos-version-min=7 \
 // RUN:   %s -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-ASAN-IOS %s
 
 // CHECK-ASAN-IOS: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN-IOS: lc++
+// CHECK-ASAN-IOS-NOT: "-lstdc++"
+// CHECK-ASAN-IOS-NOT: "-lc++"
 // CHECK-ASAN-IOS: libclang_rt.asan_ios_dynamic.dylib"
 // CHECK-ASAN-IOS: "-rpath" "@executable_path"
 // CHECK-ASAN-IOS: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target arm64-apple-tvos \
 // RUN:   -stdlib=platform -fsanitize=address -mtvos-version-min=8.3 \
 // RUN:   %s -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-ASAN-TVOS %s
 
 // CHECK-ASAN-TVOS: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN-TVOS: lc++
+// CHECK-ASAN-TVOS-NOT: "-lstdc++"
+// CHECK-ASAN-TVOS-NOT: "-lc++"
 // CHECK-ASAN-TVOS: libclang_rt.asan_tvos_dynamic.dylib"
 // CHECK-ASAN-TVOS: "-rpath" "@executable_path"
 // CHECK-ASAN-TVOS: "-rpath" "{{.*}}lib{{.*}}darwin"
 
 // RUN: %clang -no-canonical-prefixes -### -target armv7k-apple-watchos \
 // RUN:   -stdlib=platform -fsanitize=address -mwatchos-version-min=2.0 \
 // RUN:   %s -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-ASAN-WATCHOS %s
 
 // CHECK-ASAN-WATCHOS: "{{.*}}ld{{(.exe)?}}"
-// CHECK-ASAN-WATCHOS: lc++
+// CHECK-ASAN-WATCHOS-NOT: "-lstdc++"
+// CHECK-ASAN-WATCHOS-NOT: "-lc++"
 // CHECK-ASAN-WATCHOS: libclang_rt.asan_watchos_dynamic.dylib"
 // CHECK-ASAN-WATCHOS: "-rpath" "@executable_path"
 // CHECK-ASAN-WATCHOS: "-rpath" "{{.*}}lib{{.*}}darwin"