6 files changed, 20 insertions, 6 deletions
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 1f86b09cc97..d5dcdc06354 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1611,6 +1611,12 @@ def WeakRef : InheritableAttr {
   let Documentation = [Undocumented];
 }
 
+def LTOVisibilityPublic : InheritableAttr {
+  let Spellings = [CXX11<"clang", "lto_visibility_public">];
+  let Subjects = SubjectList<[Record]>;
+  let Documentation = [LTOVisibilityDocs];
+}
+
 def AnyX86Interrupt : InheritableAttr, TargetSpecificAttr<TargetAnyX86> {
   // NOTE: If you add any additional spellings, ARMInterrupt's,
   // MSP430Interrupt's and MipsInterrupt's spellings must match.
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index b1b9e444383..39c4257ddfe 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -2380,3 +2380,10 @@ The ``ifunc`` attribute may only be used on a function declaration.  A function
 Not all targets support this attribute.  ELF targets support this attribute when using binutils v2.20.1 or higher and glibc v2.11.1 or higher.  Non-ELF targets currently do not support this attribute.
   }];
 }
+
+def LTOVisibilityDocs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+See :doc:`LTOVisibility`.
+  }];
+}
diff --git a/clang/include/clang/Driver/CC1Options.td b/clang/include/clang/Driver/CC1Options.td
index e88e4bd259f..7c1777fc186 100644
--- a/clang/include/clang/Driver/CC1Options.td
+++ b/clang/include/clang/Driver/CC1Options.td
@@ -282,6 +282,9 @@ def fprofile_instrument_path_EQ : Joined<["-"], "fprofile-instrument-path=">,
 def fprofile_instrument_use_path_EQ :
     Joined<["-"], "fprofile-instrument-use-path=">,
     HelpText<"Specify the profile path in PGO use compilation">;
+def flto_visibility_public_std:
+    Flag<["-"], "flto-visibility-public-std">,
+    HelpText<"Use public LTO visibility for classes in std and stdext namespaces">;
 
 //===----------------------------------------------------------------------===//
 // Dependency Output Options
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index d2e66572884..aaa4ce92f7b 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1152,9 +1152,6 @@ def fwhole_program_vtables : Flag<["-"], "fwhole-program-vtables">, Group<f_Grou
   Flags<[CC1Option]>,
   HelpText<"Enables whole-program vtable optimization. Requires -flto">;
 def fno_whole_program_vtables : Flag<["-"], "fno-whole-program-vtables">, Group<f_Group>;
-def fwhole_program_vtables_blacklist_EQ : Joined<["-"], "fwhole-program-vtables-blacklist=">,
-  Group<f_Group>, Flags<[CC1Option]>,
-  HelpText<"Path to a blacklist file for whole-program vtable optimization">;
 def fwrapv : Flag<["-"], "fwrapv">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Treat signed integer overflow as two's complement">;
 def fwritable_strings : Flag<["-"], "fwritable-strings">, Group<f_Group>, Flags<[CC1Option]>,
diff --git a/clang/include/clang/Frontend/CodeGenOptions.def b/clang/include/clang/Frontend/CodeGenOptions.def
index 14a6ae50c1a..49b306fd777 100644
--- a/clang/include/clang/Frontend/CodeGenOptions.def
+++ b/clang/include/clang/Frontend/CodeGenOptions.def
@@ -187,6 +187,10 @@ CODEGENOPT(EmitLLVMUseLists, 1, 0) ///< Control whether to serialize use-lists.
 CODEGENOPT(WholeProgramVTables, 1, 0) ///< Whether to apply whole-program
                                       ///  vtable optimization.
 
+/// Whether to use public LTO visibility for entities in std and stdext
+/// namespaces. This is enabled by clang-cl's /MT and /MTd flags.
+CODEGENOPT(LTOVisibilityPublicStd, 1, 0)
+
 /// The user specified number of registers to be used for integral arguments,
 /// or 0 if unspecified.
 VALUE_CODEGENOPT(NumRegisterParameters, 32, 0)
diff --git a/clang/include/clang/Frontend/CodeGenOptions.h b/clang/include/clang/Frontend/CodeGenOptions.h
index be176df7f7b..71acfc6da40 100644
--- a/clang/include/clang/Frontend/CodeGenOptions.h
+++ b/clang/include/clang/Frontend/CodeGenOptions.h
@@ -199,9 +199,6 @@ public:
   /// \brief A list of all -fno-builtin-* function names (e.g., memset).
   std::vector<std::string> NoBuiltinFuncs;
 
-  /// List of blacklist files for the whole-program vtable optimization feature.
-  std::vector<std::string> WholeProgramVTablesBlacklistFiles;
-
 public:
   // Define accessors/mutators for code generation options of enumeration type.
 #define CODEGENOPT(Name, Bits, Default)