Teach `-fsanitize=fuzzer` to respect `-static` and `-static-libstdc++` when adding C++ standard libraries.

[chandlerc]

Summary

Makes linking the sanitizers follow the same logic as the rest of the
driver with respect to the static linking strategy for the C++ standard
library.

[MaskRay]

clang/lib/Driver/ToolChains/CommonArgs.cpp

754

This is correct. If GNU ld<2.25 compatibility is not needed, --push-state, -Bstatic, link, --pop-state

[chandlerc]

Ping (and adding some sanitizer folks)? I'd really love to stop building with this local patch....

clang/lib/Driver/ToolChains/CommonArgs.cpp

754

I'd prefer to keep this as-is because it matches exactly what the toolchain does elsewhere. If we want to drop support for older lds, we should update in both places.

[vitalybuka]

LGTM, but it could be better with a test

[chandlerc]

Update with a regression test.

[chandlerc]

In D80488#2341009, @vitalybuka wrote:

LGTM, but it could be better with a test

Thanks, added test and landing.

clang/lib/Driver/ToolChains/CommonArgs.cpp

collectSanitizerRuntimes(TC, Args, SharedRuntimes, StaticRuntimes,
                            RequiredSymbols);
 
   const SanitizerArgs &SanArgs = TC.getSanitizerArgs();
   // Inject libfuzzer dependencies.
   if (SanArgs.needsFuzzer() && SanArgs.linkRuntimes() &&
       !Args.hasArg(options::OPT_shared)) {
 
     addSanitizerRuntime(TC, Args, CmdArgs, "fuzzer", false, true);
-    if (!Args.hasArg(clang::driver::options::OPT_nostdlibxx))
+    if (!Args.hasArg(clang::driver::options::OPT_nostdlibxx)) {
+      bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
+                                 !Args.hasArg(options::OPT_static);
+      if (OnlyLibstdcxxStatic)
+        CmdArgs.push_back("-Bstatic");
       TC.AddCXXStdlibLibArgs(Args, CmdArgs);
+      if (OnlyLibstdcxxStatic)
+        CmdArgs.push_back("-Bdynamic");
+    }
   }
 
   for (auto RT : SharedRuntimes)
     addSanitizerRuntime(TC, Args, CmdArgs, RT, true, false);
   for (auto RT : HelperStaticRuntimes)
     addSanitizerRuntime(TC, Args, CmdArgs, RT, false, true);
   bool AddExportDynamic = false;
   for (auto RT : StaticRuntimes) {