Add support for -stdlib=libc++ in the NetBSD toolchain.

llvm-svn: 180766
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index faad1dc..06f5410 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -1861,6 +1861,42 @@
   return new tools::netbsd::Link(*this);
 }
 
+ToolChain::CXXStdlibType
+NetBSD::GetCXXStdlibType(const ArgList &Args) const {
+  if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
+    StringRef Value = A->getValue();
+    if (Value == "libstdc++")
+      return ToolChain::CST_Libstdcxx;
+    if (Value == "libc++")
+      return ToolChain::CST_Libcxx;
+
+    getDriver().Diag(diag::err_drv_invalid_stdlib_name)
+      << A->getAsString(Args);
+  }
+
+  return ToolChain::CST_Libstdcxx;
+}
+
+void NetBSD::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
+                                          ArgStringList &CC1Args) const {
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
+      DriverArgs.hasArg(options::OPT_nostdincxx))
+    return;
+
+  switch (GetCXXStdlibType(DriverArgs)) {
+  case ToolChain::CST_Libcxx:
+    addSystemInclude(DriverArgs, CC1Args,
+                     getDriver().SysRoot + "/usr/include/c++/");
+    break;
+  case ToolChain::CST_Libstdcxx:
+    addSystemInclude(DriverArgs, CC1Args,
+                     getDriver().SysRoot + "/usr/include/g++");
+    addSystemInclude(DriverArgs, CC1Args,
+                     getDriver().SysRoot + "/usr/include/g++/backward");
+    break;
+  }
+}
+
 /// Minix - Minix tool chain which can call as(1) and ld(1) directly.
 
 Minix::Minix(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)