2 files changed, 18 insertions, 3 deletions
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index bfd9429dace..ef76cbfebd9 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -253,7 +253,7 @@ static bool ParseAnalyzerArgs(AnalyzerOptions &Opts, ArgList &Args,
     for (unsigned i = 0, e = checkers.size(); i != e; ++i)
       Opts.CheckersControlList.push_back(std::make_pair(checkers[i], enable));
   }
-  
+
   // Go through the analyzer configuration options.
   for (arg_iterator it = Args.filtered_begin(OPT_analyzer_config),
        ie = Args.filtered_end(); it != ie; ++it) {
@@ -1393,6 +1393,9 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   if (Args.hasArg(OPT_fcuda_is_device))
     Opts.CUDAIsDevice = 1;
 
+  if (Args.hasArg(OPT_fcuda_allow_host_calls_from_host_device))
+    Opts.CUDAAllowHostCallsFromHostDevice = 1;
+
   if (Opts.ObjC1) {
     if (Arg *arg = Args.getLastArg(OPT_fobjc_runtime_EQ)) {
       StringRef value = arg->getValue();
diff --git a/clang/lib/Sema/SemaCUDA.cpp b/clang/lib/Sema/SemaCUDA.cpp
index 64222fbf8ac..60338212c69 100644
--- a/clang/lib/Sema/SemaCUDA.cpp
+++ b/clang/lib/Sema/SemaCUDA.cpp
@@ -92,9 +92,21 @@ bool Sema::CheckCUDATarget(const FunctionDecl *Caller,
     if (Caller->isImplicit()) return false;
 
     bool InDeviceMode = getLangOpts().CUDAIsDevice;
-    if ((InDeviceMode && CalleeTarget != CFT_Device) ||
-        (!InDeviceMode && CalleeTarget != CFT_Host))
+    if (!InDeviceMode && CalleeTarget != CFT_Host)
+        return true;
+    if (InDeviceMode && CalleeTarget != CFT_Device) {
+      // Allow host device functions to call host functions if explicitly
+      // requested.
+      if (CalleeTarget == CFT_Host &&
+          getLangOpts().CUDAAllowHostCallsFromHostDevice) {
+        Diag(Caller->getLocation(),
+             diag::warn_host_calls_from_host_device)
+            << Callee->getNameAsString() << Caller->getNameAsString();
+        return false;
+      }
+
       return true;
+    }
   }
 
   return false;