1 files changed, 24 insertions, 3 deletions
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index b418ccb0f01..bfccf7a1dbb 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5369,9 +5369,30 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(Args.MakeArgString(TargetInfo.str()));
   }
 
-  bool WholeProgramVTables =
-      Args.hasFlag(options::OPT_fwhole_program_vtables,
-                   options::OPT_fno_whole_program_vtables, false);
+  bool VirtualFunctionElimination =
+      Args.hasFlag(options::OPT_fvirtual_function_elimination,
+                   options::OPT_fno_virtual_function_elimination, false);
+  if (VirtualFunctionElimination) {
+    // VFE requires full LTO (currently, this might be relaxed to allow ThinLTO
+    // in the future).
+    if (D.getLTOMode() != LTOK_Full)
+      D.Diag(diag::err_drv_argument_only_allowed_with)
+          << "-fvirtual-function-elimination"
+          << "-flto=full";
+
+    CmdArgs.push_back("-fvirtual-function-elimination");
+  }
+
+  // VFE requires whole-program-vtables, and enables it by default.
+  bool WholeProgramVTables = Args.hasFlag(
+      options::OPT_fwhole_program_vtables,
+      options::OPT_fno_whole_program_vtables, VirtualFunctionElimination);
+  if (VirtualFunctionElimination && !WholeProgramVTables) {
+    D.Diag(diag::err_drv_argument_not_allowed_with)
+        << "-fno-whole-program-vtables"
+        << "-fvirtual-function-elimination";
+  }
+
   if (WholeProgramVTables) {
     if (!D.isUsingLTO())
       D.Diag(diag::err_drv_argument_only_allowed_with)